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1/*
2 Copyright (C) 2002 Richard Henderson
3 Copyright (C) 2001 Rusty Russell, 2002, 2010 Rusty Russell IBM.
4
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 2 of the License, or
8 (at your option) any later version.
9
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
14
15 You should have received a copy of the GNU General Public License
16 along with this program; if not, write to the Free Software
17 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18*/
19#include <linux/export.h>
20#include <linux/extable.h>
21#include <linux/moduleloader.h>
22#include <linux/trace_events.h>
23#include <linux/init.h>
24#include <linux/kallsyms.h>
25#include <linux/file.h>
26#include <linux/fs.h>
27#include <linux/sysfs.h>
28#include <linux/kernel.h>
29#include <linux/slab.h>
30#include <linux/vmalloc.h>
31#include <linux/elf.h>
32#include <linux/proc_fs.h>
33#include <linux/security.h>
34#include <linux/seq_file.h>
35#include <linux/syscalls.h>
36#include <linux/fcntl.h>
37#include <linux/rcupdate.h>
38#include <linux/capability.h>
39#include <linux/cpu.h>
40#include <linux/moduleparam.h>
41#include <linux/errno.h>
42#include <linux/err.h>
43#include <linux/vermagic.h>
44#include <linux/notifier.h>
45#include <linux/sched.h>
46#include <linux/device.h>
47#include <linux/string.h>
48#include <linux/mutex.h>
49#include <linux/rculist.h>
50#include <linux/uaccess.h>
51#include <asm/cacheflush.h>
52#include <linux/set_memory.h>
53#include <asm/mmu_context.h>
54#include <linux/license.h>
55#include <asm/sections.h>
56#include <linux/tracepoint.h>
57#include <linux/ftrace.h>
58#include <linux/livepatch.h>
59#include <linux/async.h>
60#include <linux/percpu.h>
61#include <linux/kmemleak.h>
62#include <linux/jump_label.h>
63#include <linux/pfn.h>
64#include <linux/bsearch.h>
65#include <linux/dynamic_debug.h>
66#include <linux/audit.h>
67#include <uapi/linux/module.h>
68#include "module-internal.h"
69
70#define CREATE_TRACE_POINTS
71#include <trace/events/module.h>
72
73#ifndef ARCH_SHF_SMALL
74#define ARCH_SHF_SMALL 0
75#endif
76
77/*
78 * Modules' sections will be aligned on page boundaries
79 * to ensure complete separation of code and data, but
80 * only when CONFIG_STRICT_MODULE_RWX=y
81 */
82#ifdef CONFIG_STRICT_MODULE_RWX
83# define debug_align(X) ALIGN(X, PAGE_SIZE)
84#else
85# define debug_align(X) (X)
86#endif
87
88/* If this is set, the section belongs in the init part of the module */
89#define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
90
91/*
92 * Mutex protects:
93 * 1) List of modules (also safely readable with preempt_disable),
94 * 2) module_use links,
95 * 3) module_addr_min/module_addr_max.
96 * (delete and add uses RCU list operations). */
97DEFINE_MUTEX(module_mutex);
98EXPORT_SYMBOL_GPL(module_mutex);
99static LIST_HEAD(modules);
100
101#ifdef CONFIG_MODULES_TREE_LOOKUP
102
103/*
104 * Use a latched RB-tree for __module_address(); this allows us to use
105 * RCU-sched lookups of the address from any context.
106 *
107 * This is conditional on PERF_EVENTS || TRACING because those can really hit
108 * __module_address() hard by doing a lot of stack unwinding; potentially from
109 * NMI context.
110 */
111
112static __always_inline unsigned long __mod_tree_val(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->base;
117}
118
119static __always_inline unsigned long __mod_tree_size(struct latch_tree_node *n)
120{
121 struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
122
123 return (unsigned long)layout->size;
124}
125
126static __always_inline bool
127mod_tree_less(struct latch_tree_node *a, struct latch_tree_node *b)
128{
129 return __mod_tree_val(a) < __mod_tree_val(b);
130}
131
132static __always_inline int
133mod_tree_comp(void *key, struct latch_tree_node *n)
134{
135 unsigned long val = (unsigned long)key;
136 unsigned long start, end;
137
138 start = __mod_tree_val(n);
139 if (val < start)
140 return -1;
141
142 end = start + __mod_tree_size(n);
143 if (val >= end)
144 return 1;
145
146 return 0;
147}
148
149static const struct latch_tree_ops mod_tree_ops = {
150 .less = mod_tree_less,
151 .comp = mod_tree_comp,
152};
153
154static struct mod_tree_root {
155 struct latch_tree_root root;
156 unsigned long addr_min;
157 unsigned long addr_max;
158} mod_tree __cacheline_aligned = {
159 .addr_min = -1UL,
160};
161
162#define module_addr_min mod_tree.addr_min
163#define module_addr_max mod_tree.addr_max
164
165static noinline void __mod_tree_insert(struct mod_tree_node *node)
166{
167 latch_tree_insert(&node->node, &mod_tree.root, &mod_tree_ops);
168}
169
170static void __mod_tree_remove(struct mod_tree_node *node)
171{
172 latch_tree_erase(&node->node, &mod_tree.root, &mod_tree_ops);
173}
174
175/*
176 * These modifications: insert, remove_init and remove; are serialized by the
177 * module_mutex.
178 */
179static void mod_tree_insert(struct module *mod)
180{
181 mod->core_layout.mtn.mod = mod;
182 mod->init_layout.mtn.mod = mod;
183
184 __mod_tree_insert(&mod->core_layout.mtn);
185 if (mod->init_layout.size)
186 __mod_tree_insert(&mod->init_layout.mtn);
187}
188
189static void mod_tree_remove_init(struct module *mod)
190{
191 if (mod->init_layout.size)
192 __mod_tree_remove(&mod->init_layout.mtn);
193}
194
195static void mod_tree_remove(struct module *mod)
196{
197 __mod_tree_remove(&mod->core_layout.mtn);
198 mod_tree_remove_init(mod);
199}
200
201static struct module *mod_find(unsigned long addr)
202{
203 struct latch_tree_node *ltn;
204
205 ltn = latch_tree_find((void *)addr, &mod_tree.root, &mod_tree_ops);
206 if (!ltn)
207 return NULL;
208
209 return container_of(ltn, struct mod_tree_node, node)->mod;
210}
211
212#else /* MODULES_TREE_LOOKUP */
213
214static unsigned long module_addr_min = -1UL, module_addr_max = 0;
215
216static void mod_tree_insert(struct module *mod) { }
217static void mod_tree_remove_init(struct module *mod) { }
218static void mod_tree_remove(struct module *mod) { }
219
220static struct module *mod_find(unsigned long addr)
221{
222 struct module *mod;
223
224 list_for_each_entry_rcu(mod, &modules, list) {
225 if (within_module(addr, mod))
226 return mod;
227 }
228
229 return NULL;
230}
231
232#endif /* MODULES_TREE_LOOKUP */
233
234/*
235 * Bounds of module text, for speeding up __module_address.
236 * Protected by module_mutex.
237 */
238static void __mod_update_bounds(void *base, unsigned int size)
239{
240 unsigned long min = (unsigned long)base;
241 unsigned long max = min + size;
242
243 if (min < module_addr_min)
244 module_addr_min = min;
245 if (max > module_addr_max)
246 module_addr_max = max;
247}
248
249static void mod_update_bounds(struct module *mod)
250{
251 __mod_update_bounds(mod->core_layout.base, mod->core_layout.size);
252 if (mod->init_layout.size)
253 __mod_update_bounds(mod->init_layout.base, mod->init_layout.size);
254}
255
256#ifdef CONFIG_KGDB_KDB
257struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
258#endif /* CONFIG_KGDB_KDB */
259
260static void module_assert_mutex(void)
261{
262 lockdep_assert_held(&module_mutex);
263}
264
265static void module_assert_mutex_or_preempt(void)
266{
267#ifdef CONFIG_LOCKDEP
268 if (unlikely(!debug_locks))
269 return;
270
271 WARN_ON_ONCE(!rcu_read_lock_sched_held() &&
272 !lockdep_is_held(&module_mutex));
273#endif
274}
275
276static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE);
277#ifndef CONFIG_MODULE_SIG_FORCE
278module_param(sig_enforce, bool_enable_only, 0644);
279#endif /* !CONFIG_MODULE_SIG_FORCE */
280
281/*
282 * Export sig_enforce kernel cmdline parameter to allow other subsystems rely
283 * on that instead of directly to CONFIG_MODULE_SIG_FORCE config.
284 */
285bool is_module_sig_enforced(void)
286{
287 return sig_enforce;
288}
289EXPORT_SYMBOL(is_module_sig_enforced);
290
291/* Block module loading/unloading? */
292int modules_disabled = 0;
293core_param(nomodule, modules_disabled, bint, 0);
294
295/* Waiting for a module to finish initializing? */
296static DECLARE_WAIT_QUEUE_HEAD(module_wq);
297
298static BLOCKING_NOTIFIER_HEAD(module_notify_list);
299
300int register_module_notifier(struct notifier_block *nb)
301{
302 return blocking_notifier_chain_register(&module_notify_list, nb);
303}
304EXPORT_SYMBOL(register_module_notifier);
305
306int unregister_module_notifier(struct notifier_block *nb)
307{
308 return blocking_notifier_chain_unregister(&module_notify_list, nb);
309}
310EXPORT_SYMBOL(unregister_module_notifier);
311
312struct load_info {
313 const char *name;
314 Elf_Ehdr *hdr;
315 unsigned long len;
316 Elf_Shdr *sechdrs;
317 char *secstrings, *strtab;
318 unsigned long symoffs, stroffs;
319 struct _ddebug *debug;
320 unsigned int num_debug;
321 bool sig_ok;
322#ifdef CONFIG_KALLSYMS
323 unsigned long mod_kallsyms_init_off;
324#endif
325 struct {
326 unsigned int sym, str, mod, vers, info, pcpu;
327 } index;
328};
329
330/*
331 * We require a truly strong try_module_get(): 0 means success.
332 * Otherwise an error is returned due to ongoing or failed
333 * initialization etc.
334 */
335static inline int strong_try_module_get(struct module *mod)
336{
337 BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED);
338 if (mod && mod->state == MODULE_STATE_COMING)
339 return -EBUSY;
340 if (try_module_get(mod))
341 return 0;
342 else
343 return -ENOENT;
344}
345
346static inline void add_taint_module(struct module *mod, unsigned flag,
347 enum lockdep_ok lockdep_ok)
348{
349 add_taint(flag, lockdep_ok);
350 set_bit(flag, &mod->taints);
351}
352
353/*
354 * A thread that wants to hold a reference to a module only while it
355 * is running can call this to safely exit. nfsd and lockd use this.
356 */
357void __noreturn __module_put_and_exit(struct module *mod, long code)
358{
359 module_put(mod);
360 do_exit(code);
361}
362EXPORT_SYMBOL(__module_put_and_exit);
363
364/* Find a module section: 0 means not found. */
365static unsigned int find_sec(const struct load_info *info, const char *name)
366{
367 unsigned int i;
368
369 for (i = 1; i < info->hdr->e_shnum; i++) {
370 Elf_Shdr *shdr = &info->sechdrs[i];
371 /* Alloc bit cleared means "ignore it." */
372 if ((shdr->sh_flags & SHF_ALLOC)
373 && strcmp(info->secstrings + shdr->sh_name, name) == 0)
374 return i;
375 }
376 return 0;
377}
378
379/* Find a module section, or NULL. */
380static void *section_addr(const struct load_info *info, const char *name)
381{
382 /* Section 0 has sh_addr 0. */
383 return (void *)info->sechdrs[find_sec(info, name)].sh_addr;
384}
385
386/* Find a module section, or NULL. Fill in number of "objects" in section. */
387static void *section_objs(const struct load_info *info,
388 const char *name,
389 size_t object_size,
390 unsigned int *num)
391{
392 unsigned int sec = find_sec(info, name);
393
394 /* Section 0 has sh_addr 0 and sh_size 0. */
395 *num = info->sechdrs[sec].sh_size / object_size;
396 return (void *)info->sechdrs[sec].sh_addr;
397}
398
399/* Provided by the linker */
400extern const struct kernel_symbol __start___ksymtab[];
401extern const struct kernel_symbol __stop___ksymtab[];
402extern const struct kernel_symbol __start___ksymtab_gpl[];
403extern const struct kernel_symbol __stop___ksymtab_gpl[];
404extern const struct kernel_symbol __start___ksymtab_gpl_future[];
405extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
406extern const s32 __start___kcrctab[];
407extern const s32 __start___kcrctab_gpl[];
408extern const s32 __start___kcrctab_gpl_future[];
409#ifdef CONFIG_UNUSED_SYMBOLS
410extern const struct kernel_symbol __start___ksymtab_unused[];
411extern const struct kernel_symbol __stop___ksymtab_unused[];
412extern const struct kernel_symbol __start___ksymtab_unused_gpl[];
413extern const struct kernel_symbol __stop___ksymtab_unused_gpl[];
414extern const s32 __start___kcrctab_unused[];
415extern const s32 __start___kcrctab_unused_gpl[];
416#endif
417
418#ifndef CONFIG_MODVERSIONS
419#define symversion(base, idx) NULL
420#else
421#define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
422#endif
423
424static bool each_symbol_in_section(const struct symsearch *arr,
425 unsigned int arrsize,
426 struct module *owner,
427 bool (*fn)(const struct symsearch *syms,
428 struct module *owner,
429 void *data),
430 void *data)
431{
432 unsigned int j;
433
434 for (j = 0; j < arrsize; j++) {
435 if (fn(&arr[j], owner, data))
436 return true;
437 }
438
439 return false;
440}
441
442/* Returns true as soon as fn returns true, otherwise false. */
443bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
444 struct module *owner,
445 void *data),
446 void *data)
447{
448 struct module *mod;
449 static const struct symsearch arr[] = {
450 { __start___ksymtab, __stop___ksymtab, __start___kcrctab,
451 NOT_GPL_ONLY, false },
452 { __start___ksymtab_gpl, __stop___ksymtab_gpl,
453 __start___kcrctab_gpl,
454 GPL_ONLY, false },
455 { __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future,
456 __start___kcrctab_gpl_future,
457 WILL_BE_GPL_ONLY, false },
458#ifdef CONFIG_UNUSED_SYMBOLS
459 { __start___ksymtab_unused, __stop___ksymtab_unused,
460 __start___kcrctab_unused,
461 NOT_GPL_ONLY, true },
462 { __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl,
463 __start___kcrctab_unused_gpl,
464 GPL_ONLY, true },
465#endif
466 };
467
468 module_assert_mutex_or_preempt();
469
470 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data))
471 return true;
472
473 list_for_each_entry_rcu(mod, &modules, list) {
474 struct symsearch arr[] = {
475 { mod->syms, mod->syms + mod->num_syms, mod->crcs,
476 NOT_GPL_ONLY, false },
477 { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
478 mod->gpl_crcs,
479 GPL_ONLY, false },
480 { mod->gpl_future_syms,
481 mod->gpl_future_syms + mod->num_gpl_future_syms,
482 mod->gpl_future_crcs,
483 WILL_BE_GPL_ONLY, false },
484#ifdef CONFIG_UNUSED_SYMBOLS
485 { mod->unused_syms,
486 mod->unused_syms + mod->num_unused_syms,
487 mod->unused_crcs,
488 NOT_GPL_ONLY, true },
489 { mod->unused_gpl_syms,
490 mod->unused_gpl_syms + mod->num_unused_gpl_syms,
491 mod->unused_gpl_crcs,
492 GPL_ONLY, true },
493#endif
494 };
495
496 if (mod->state == MODULE_STATE_UNFORMED)
497 continue;
498
499 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data))
500 return true;
501 }
502 return false;
503}
504EXPORT_SYMBOL_GPL(each_symbol_section);
505
506struct find_symbol_arg {
507 /* Input */
508 const char *name;
509 bool gplok;
510 bool warn;
511
512 /* Output */
513 struct module *owner;
514 const s32 *crc;
515 const struct kernel_symbol *sym;
516};
517
518static bool check_symbol(const struct symsearch *syms,
519 struct module *owner,
520 unsigned int symnum, void *data)
521{
522 struct find_symbol_arg *fsa = data;
523
524 if (!fsa->gplok) {
525 if (syms->licence == GPL_ONLY)
526 return false;
527 if (syms->licence == WILL_BE_GPL_ONLY && fsa->warn) {
528 pr_warn("Symbol %s is being used by a non-GPL module, "
529 "which will not be allowed in the future\n",
530 fsa->name);
531 }
532 }
533
534#ifdef CONFIG_UNUSED_SYMBOLS
535 if (syms->unused && fsa->warn) {
536 pr_warn("Symbol %s is marked as UNUSED, however this module is "
537 "using it.\n", fsa->name);
538 pr_warn("This symbol will go away in the future.\n");
539 pr_warn("Please evaluate if this is the right api to use and "
540 "if it really is, submit a report to the linux kernel "
541 "mailing list together with submitting your code for "
542 "inclusion.\n");
543 }
544#endif
545
546 fsa->owner = owner;
547 fsa->crc = symversion(syms->crcs, symnum);
548 fsa->sym = &syms->start[symnum];
549 return true;
550}
551
552static int cmp_name(const void *va, const void *vb)
553{
554 const char *a;
555 const struct kernel_symbol *b;
556 a = va; b = vb;
557 return strcmp(a, b->name);
558}
559
560static bool find_symbol_in_section(const struct symsearch *syms,
561 struct module *owner,
562 void *data)
563{
564 struct find_symbol_arg *fsa = data;
565 struct kernel_symbol *sym;
566
567 sym = bsearch(fsa->name, syms->start, syms->stop - syms->start,
568 sizeof(struct kernel_symbol), cmp_name);
569
570 if (sym != NULL && check_symbol(syms, owner, sym - syms->start, data))
571 return true;
572
573 return false;
574}
575
576/* Find a symbol and return it, along with, (optional) crc and
577 * (optional) module which owns it. Needs preempt disabled or module_mutex. */
578const struct kernel_symbol *find_symbol(const char *name,
579 struct module **owner,
580 const s32 **crc,
581 bool gplok,
582 bool warn)
583{
584 struct find_symbol_arg fsa;
585
586 fsa.name = name;
587 fsa.gplok = gplok;
588 fsa.warn = warn;
589
590 if (each_symbol_section(find_symbol_in_section, &fsa)) {
591 if (owner)
592 *owner = fsa.owner;
593 if (crc)
594 *crc = fsa.crc;
595 return fsa.sym;
596 }
597
598 pr_debug("Failed to find symbol %s\n", name);
599 return NULL;
600}
601EXPORT_SYMBOL_GPL(find_symbol);
602
603/*
604 * Search for module by name: must hold module_mutex (or preempt disabled
605 * for read-only access).
606 */
607static struct module *find_module_all(const char *name, size_t len,
608 bool even_unformed)
609{
610 struct module *mod;
611
612 module_assert_mutex_or_preempt();
613
614 list_for_each_entry_rcu(mod, &modules, list) {
615 if (!even_unformed && mod->state == MODULE_STATE_UNFORMED)
616 continue;
617 if (strlen(mod->name) == len && !memcmp(mod->name, name, len))
618 return mod;
619 }
620 return NULL;
621}
622
623struct module *find_module(const char *name)
624{
625 module_assert_mutex();
626 return find_module_all(name, strlen(name), false);
627}
628EXPORT_SYMBOL_GPL(find_module);
629
630#ifdef CONFIG_SMP
631
632static inline void __percpu *mod_percpu(struct module *mod)
633{
634 return mod->percpu;
635}
636
637static int percpu_modalloc(struct module *mod, struct load_info *info)
638{
639 Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu];
640 unsigned long align = pcpusec->sh_addralign;
641
642 if (!pcpusec->sh_size)
643 return 0;
644
645 if (align > PAGE_SIZE) {
646 pr_warn("%s: per-cpu alignment %li > %li\n",
647 mod->name, align, PAGE_SIZE);
648 align = PAGE_SIZE;
649 }
650
651 mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align);
652 if (!mod->percpu) {
653 pr_warn("%s: Could not allocate %lu bytes percpu data\n",
654 mod->name, (unsigned long)pcpusec->sh_size);
655 return -ENOMEM;
656 }
657 mod->percpu_size = pcpusec->sh_size;
658 return 0;
659}
660
661static void percpu_modfree(struct module *mod)
662{
663 free_percpu(mod->percpu);
664}
665
666static unsigned int find_pcpusec(struct load_info *info)
667{
668 return find_sec(info, ".data..percpu");
669}
670
671static void percpu_modcopy(struct module *mod,
672 const void *from, unsigned long size)
673{
674 int cpu;
675
676 for_each_possible_cpu(cpu)
677 memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
678}
679
680bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
681{
682 struct module *mod;
683 unsigned int cpu;
684
685 preempt_disable();
686
687 list_for_each_entry_rcu(mod, &modules, list) {
688 if (mod->state == MODULE_STATE_UNFORMED)
689 continue;
690 if (!mod->percpu_size)
691 continue;
692 for_each_possible_cpu(cpu) {
693 void *start = per_cpu_ptr(mod->percpu, cpu);
694 void *va = (void *)addr;
695
696 if (va >= start && va < start + mod->percpu_size) {
697 if (can_addr) {
698 *can_addr = (unsigned long) (va - start);
699 *can_addr += (unsigned long)
700 per_cpu_ptr(mod->percpu,
701 get_boot_cpu_id());
702 }
703 preempt_enable();
704 return true;
705 }
706 }
707 }
708
709 preempt_enable();
710 return false;
711}
712
713/**
714 * is_module_percpu_address - test whether address is from module static percpu
715 * @addr: address to test
716 *
717 * Test whether @addr belongs to module static percpu area.
718 *
719 * RETURNS:
720 * %true if @addr is from module static percpu area
721 */
722bool is_module_percpu_address(unsigned long addr)
723{
724 return __is_module_percpu_address(addr, NULL);
725}
726
727#else /* ... !CONFIG_SMP */
728
729static inline void __percpu *mod_percpu(struct module *mod)
730{
731 return NULL;
732}
733static int percpu_modalloc(struct module *mod, struct load_info *info)
734{
735 /* UP modules shouldn't have this section: ENOMEM isn't quite right */
736 if (info->sechdrs[info->index.pcpu].sh_size != 0)
737 return -ENOMEM;
738 return 0;
739}
740static inline void percpu_modfree(struct module *mod)
741{
742}
743static unsigned int find_pcpusec(struct load_info *info)
744{
745 return 0;
746}
747static inline void percpu_modcopy(struct module *mod,
748 const void *from, unsigned long size)
749{
750 /* pcpusec should be 0, and size of that section should be 0. */
751 BUG_ON(size != 0);
752}
753bool is_module_percpu_address(unsigned long addr)
754{
755 return false;
756}
757
758bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
759{
760 return false;
761}
762
763#endif /* CONFIG_SMP */
764
765#define MODINFO_ATTR(field) \
766static void setup_modinfo_##field(struct module *mod, const char *s) \
767{ \
768 mod->field = kstrdup(s, GFP_KERNEL); \
769} \
770static ssize_t show_modinfo_##field(struct module_attribute *mattr, \
771 struct module_kobject *mk, char *buffer) \
772{ \
773 return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field); \
774} \
775static int modinfo_##field##_exists(struct module *mod) \
776{ \
777 return mod->field != NULL; \
778} \
779static void free_modinfo_##field(struct module *mod) \
780{ \
781 kfree(mod->field); \
782 mod->field = NULL; \
783} \
784static struct module_attribute modinfo_##field = { \
785 .attr = { .name = __stringify(field), .mode = 0444 }, \
786 .show = show_modinfo_##field, \
787 .setup = setup_modinfo_##field, \
788 .test = modinfo_##field##_exists, \
789 .free = free_modinfo_##field, \
790};
791
792MODINFO_ATTR(version);
793MODINFO_ATTR(srcversion);
794
795static char last_unloaded_module[MODULE_NAME_LEN+1];
796
797#ifdef CONFIG_MODULE_UNLOAD
798
799EXPORT_TRACEPOINT_SYMBOL(module_get);
800
801/* MODULE_REF_BASE is the base reference count by kmodule loader. */
802#define MODULE_REF_BASE 1
803
804/* Init the unload section of the module. */
805static int module_unload_init(struct module *mod)
806{
807 /*
808 * Initialize reference counter to MODULE_REF_BASE.
809 * refcnt == 0 means module is going.
810 */
811 atomic_set(&mod->refcnt, MODULE_REF_BASE);
812
813 INIT_LIST_HEAD(&mod->source_list);
814 INIT_LIST_HEAD(&mod->target_list);
815
816 /* Hold reference count during initialization. */
817 atomic_inc(&mod->refcnt);
818
819 return 0;
820}
821
822/* Does a already use b? */
823static int already_uses(struct module *a, struct module *b)
824{
825 struct module_use *use;
826
827 list_for_each_entry(use, &b->source_list, source_list) {
828 if (use->source == a) {
829 pr_debug("%s uses %s!\n", a->name, b->name);
830 return 1;
831 }
832 }
833 pr_debug("%s does not use %s!\n", a->name, b->name);
834 return 0;
835}
836
837/*
838 * Module a uses b
839 * - we add 'a' as a "source", 'b' as a "target" of module use
840 * - the module_use is added to the list of 'b' sources (so
841 * 'b' can walk the list to see who sourced them), and of 'a'
842 * targets (so 'a' can see what modules it targets).
843 */
844static int add_module_usage(struct module *a, struct module *b)
845{
846 struct module_use *use;
847
848 pr_debug("Allocating new usage for %s.\n", a->name);
849 use = kmalloc(sizeof(*use), GFP_ATOMIC);
850 if (!use)
851 return -ENOMEM;
852
853 use->source = a;
854 use->target = b;
855 list_add(&use->source_list, &b->source_list);
856 list_add(&use->target_list, &a->target_list);
857 return 0;
858}
859
860/* Module a uses b: caller needs module_mutex() */
861int ref_module(struct module *a, struct module *b)
862{
863 int err;
864
865 if (b == NULL || already_uses(a, b))
866 return 0;
867
868 /* If module isn't available, we fail. */
869 err = strong_try_module_get(b);
870 if (err)
871 return err;
872
873 err = add_module_usage(a, b);
874 if (err) {
875 module_put(b);
876 return err;
877 }
878 return 0;
879}
880EXPORT_SYMBOL_GPL(ref_module);
881
882/* Clear the unload stuff of the module. */
883static void module_unload_free(struct module *mod)
884{
885 struct module_use *use, *tmp;
886
887 mutex_lock(&module_mutex);
888 list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
889 struct module *i = use->target;
890 pr_debug("%s unusing %s\n", mod->name, i->name);
891 module_put(i);
892 list_del(&use->source_list);
893 list_del(&use->target_list);
894 kfree(use);
895 }
896 mutex_unlock(&module_mutex);
897}
898
899#ifdef CONFIG_MODULE_FORCE_UNLOAD
900static inline int try_force_unload(unsigned int flags)
901{
902 int ret = (flags & O_TRUNC);
903 if (ret)
904 add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE);
905 return ret;
906}
907#else
908static inline int try_force_unload(unsigned int flags)
909{
910 return 0;
911}
912#endif /* CONFIG_MODULE_FORCE_UNLOAD */
913
914/* Try to release refcount of module, 0 means success. */
915static int try_release_module_ref(struct module *mod)
916{
917 int ret;
918
919 /* Try to decrement refcnt which we set at loading */
920 ret = atomic_sub_return(MODULE_REF_BASE, &mod->refcnt);
921 BUG_ON(ret < 0);
922 if (ret)
923 /* Someone can put this right now, recover with checking */
924 ret = atomic_add_unless(&mod->refcnt, MODULE_REF_BASE, 0);
925
926 return ret;
927}
928
929static int try_stop_module(struct module *mod, int flags, int *forced)
930{
931 /* If it's not unused, quit unless we're forcing. */
932 if (try_release_module_ref(mod) != 0) {
933 *forced = try_force_unload(flags);
934 if (!(*forced))
935 return -EWOULDBLOCK;
936 }
937
938 /* Mark it as dying. */
939 mod->state = MODULE_STATE_GOING;
940
941 return 0;
942}
943
944/**
945 * module_refcount - return the refcount or -1 if unloading
946 *
947 * @mod: the module we're checking
948 *
949 * Returns:
950 * -1 if the module is in the process of unloading
951 * otherwise the number of references in the kernel to the module
952 */
953int module_refcount(struct module *mod)
954{
955 return atomic_read(&mod->refcnt) - MODULE_REF_BASE;
956}
957EXPORT_SYMBOL(module_refcount);
958
959/* This exists whether we can unload or not */
960static void free_module(struct module *mod);
961
962SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
963 unsigned int, flags)
964{
965 struct module *mod;
966 char name[MODULE_NAME_LEN];
967 int ret, forced = 0;
968
969 if (!capable(CAP_SYS_MODULE) || modules_disabled)
970 return -EPERM;
971
972 if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
973 return -EFAULT;
974 name[MODULE_NAME_LEN-1] = '\0';
975
976 audit_log_kern_module(name);
977
978 if (mutex_lock_interruptible(&module_mutex) != 0)
979 return -EINTR;
980
981 mod = find_module(name);
982 if (!mod) {
983 ret = -ENOENT;
984 goto out;
985 }
986
987 if (!list_empty(&mod->source_list)) {
988 /* Other modules depend on us: get rid of them first. */
989 ret = -EWOULDBLOCK;
990 goto out;
991 }
992
993 /* Doing init or already dying? */
994 if (mod->state != MODULE_STATE_LIVE) {
995 /* FIXME: if (force), slam module count damn the torpedoes */
996 pr_debug("%s already dying\n", mod->name);
997 ret = -EBUSY;
998 goto out;
999 }
1000
1001 /* If it has an init func, it must have an exit func to unload */
1002 if (mod->init && !mod->exit) {
1003 forced = try_force_unload(flags);
1004 if (!forced) {
1005 /* This module can't be removed */
1006 ret = -EBUSY;
1007 goto out;
1008 }
1009 }
1010
1011 /* Stop the machine so refcounts can't move and disable module. */
1012 ret = try_stop_module(mod, flags, &forced);
1013 if (ret != 0)
1014 goto out;
1015
1016 mutex_unlock(&module_mutex);
1017 /* Final destruction now no one is using it. */
1018 if (mod->exit != NULL)
1019 mod->exit();
1020 blocking_notifier_call_chain(&module_notify_list,
1021 MODULE_STATE_GOING, mod);
1022 klp_module_going(mod);
1023 ftrace_release_mod(mod);
1024
1025 async_synchronize_full();
1026
1027 /* Store the name of the last unloaded module for diagnostic purposes */
1028 strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
1029
1030 free_module(mod);
1031 return 0;
1032out:
1033 mutex_unlock(&module_mutex);
1034 return ret;
1035}
1036
1037static inline void print_unload_info(struct seq_file *m, struct module *mod)
1038{
1039 struct module_use *use;
1040 int printed_something = 0;
1041
1042 seq_printf(m, " %i ", module_refcount(mod));
1043
1044 /*
1045 * Always include a trailing , so userspace can differentiate
1046 * between this and the old multi-field proc format.
1047 */
1048 list_for_each_entry(use, &mod->source_list, source_list) {
1049 printed_something = 1;
1050 seq_printf(m, "%s,", use->source->name);
1051 }
1052
1053 if (mod->init != NULL && mod->exit == NULL) {
1054 printed_something = 1;
1055 seq_puts(m, "[permanent],");
1056 }
1057
1058 if (!printed_something)
1059 seq_puts(m, "-");
1060}
1061
1062void __symbol_put(const char *symbol)
1063{
1064 struct module *owner;
1065
1066 preempt_disable();
1067 if (!find_symbol(symbol, &owner, NULL, true, false))
1068 BUG();
1069 module_put(owner);
1070 preempt_enable();
1071}
1072EXPORT_SYMBOL(__symbol_put);
1073
1074/* Note this assumes addr is a function, which it currently always is. */
1075void symbol_put_addr(void *addr)
1076{
1077 struct module *modaddr;
1078 unsigned long a = (unsigned long)dereference_function_descriptor(addr);
1079
1080 if (core_kernel_text(a))
1081 return;
1082
1083 /*
1084 * Even though we hold a reference on the module; we still need to
1085 * disable preemption in order to safely traverse the data structure.
1086 */
1087 preempt_disable();
1088 modaddr = __module_text_address(a);
1089 BUG_ON(!modaddr);
1090 module_put(modaddr);
1091 preempt_enable();
1092}
1093EXPORT_SYMBOL_GPL(symbol_put_addr);
1094
1095static ssize_t show_refcnt(struct module_attribute *mattr,
1096 struct module_kobject *mk, char *buffer)
1097{
1098 return sprintf(buffer, "%i\n", module_refcount(mk->mod));
1099}
1100
1101static struct module_attribute modinfo_refcnt =
1102 __ATTR(refcnt, 0444, show_refcnt, NULL);
1103
1104void __module_get(struct module *module)
1105{
1106 if (module) {
1107 preempt_disable();
1108 atomic_inc(&module->refcnt);
1109 trace_module_get(module, _RET_IP_);
1110 preempt_enable();
1111 }
1112}
1113EXPORT_SYMBOL(__module_get);
1114
1115bool try_module_get(struct module *module)
1116{
1117 bool ret = true;
1118
1119 if (module) {
1120 preempt_disable();
1121 /* Note: here, we can fail to get a reference */
1122 if (likely(module_is_live(module) &&
1123 atomic_inc_not_zero(&module->refcnt) != 0))
1124 trace_module_get(module, _RET_IP_);
1125 else
1126 ret = false;
1127
1128 preempt_enable();
1129 }
1130 return ret;
1131}
1132EXPORT_SYMBOL(try_module_get);
1133
1134void module_put(struct module *module)
1135{
1136 int ret;
1137
1138 if (module) {
1139 preempt_disable();
1140 ret = atomic_dec_if_positive(&module->refcnt);
1141 WARN_ON(ret < 0); /* Failed to put refcount */
1142 trace_module_put(module, _RET_IP_);
1143 preempt_enable();
1144 }
1145}
1146EXPORT_SYMBOL(module_put);
1147
1148#else /* !CONFIG_MODULE_UNLOAD */
1149static inline void print_unload_info(struct seq_file *m, struct module *mod)
1150{
1151 /* We don't know the usage count, or what modules are using. */
1152 seq_puts(m, " - -");
1153}
1154
1155static inline void module_unload_free(struct module *mod)
1156{
1157}
1158
1159int ref_module(struct module *a, struct module *b)
1160{
1161 return strong_try_module_get(b);
1162}
1163EXPORT_SYMBOL_GPL(ref_module);
1164
1165static inline int module_unload_init(struct module *mod)
1166{
1167 return 0;
1168}
1169#endif /* CONFIG_MODULE_UNLOAD */
1170
1171static size_t module_flags_taint(struct module *mod, char *buf)
1172{
1173 size_t l = 0;
1174 int i;
1175
1176 for (i = 0; i < TAINT_FLAGS_COUNT; i++) {
1177 if (taint_flags[i].module && test_bit(i, &mod->taints))
1178 buf[l++] = taint_flags[i].c_true;
1179 }
1180
1181 return l;
1182}
1183
1184static ssize_t show_initstate(struct module_attribute *mattr,
1185 struct module_kobject *mk, char *buffer)
1186{
1187 const char *state = "unknown";
1188
1189 switch (mk->mod->state) {
1190 case MODULE_STATE_LIVE:
1191 state = "live";
1192 break;
1193 case MODULE_STATE_COMING:
1194 state = "coming";
1195 break;
1196 case MODULE_STATE_GOING:
1197 state = "going";
1198 break;
1199 default:
1200 BUG();
1201 }
1202 return sprintf(buffer, "%s\n", state);
1203}
1204
1205static struct module_attribute modinfo_initstate =
1206 __ATTR(initstate, 0444, show_initstate, NULL);
1207
1208static ssize_t store_uevent(struct module_attribute *mattr,
1209 struct module_kobject *mk,
1210 const char *buffer, size_t count)
1211{
1212 kobject_synth_uevent(&mk->kobj, buffer, count);
1213 return count;
1214}
1215
1216struct module_attribute module_uevent =
1217 __ATTR(uevent, 0200, NULL, store_uevent);
1218
1219static ssize_t show_coresize(struct module_attribute *mattr,
1220 struct module_kobject *mk, char *buffer)
1221{
1222 return sprintf(buffer, "%u\n", mk->mod->core_layout.size);
1223}
1224
1225static struct module_attribute modinfo_coresize =
1226 __ATTR(coresize, 0444, show_coresize, NULL);
1227
1228static ssize_t show_initsize(struct module_attribute *mattr,
1229 struct module_kobject *mk, char *buffer)
1230{
1231 return sprintf(buffer, "%u\n", mk->mod->init_layout.size);
1232}
1233
1234static struct module_attribute modinfo_initsize =
1235 __ATTR(initsize, 0444, show_initsize, NULL);
1236
1237static ssize_t show_taint(struct module_attribute *mattr,
1238 struct module_kobject *mk, char *buffer)
1239{
1240 size_t l;
1241
1242 l = module_flags_taint(mk->mod, buffer);
1243 buffer[l++] = '\n';
1244 return l;
1245}
1246
1247static struct module_attribute modinfo_taint =
1248 __ATTR(taint, 0444, show_taint, NULL);
1249
1250static struct module_attribute *modinfo_attrs[] = {
1251 &module_uevent,
1252 &modinfo_version,
1253 &modinfo_srcversion,
1254 &modinfo_initstate,
1255 &modinfo_coresize,
1256 &modinfo_initsize,
1257 &modinfo_taint,
1258#ifdef CONFIG_MODULE_UNLOAD
1259 &modinfo_refcnt,
1260#endif
1261 NULL,
1262};
1263
1264static const char vermagic[] = VERMAGIC_STRING;
1265
1266static int try_to_force_load(struct module *mod, const char *reason)
1267{
1268#ifdef CONFIG_MODULE_FORCE_LOAD
1269 if (!test_taint(TAINT_FORCED_MODULE))
1270 pr_warn("%s: %s: kernel tainted.\n", mod->name, reason);
1271 add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
1272 return 0;
1273#else
1274 return -ENOEXEC;
1275#endif
1276}
1277
1278#ifdef CONFIG_MODVERSIONS
1279
1280static u32 resolve_rel_crc(const s32 *crc)
1281{
1282 return *(u32 *)((void *)crc + *crc);
1283}
1284
1285static int check_version(const struct load_info *info,
1286 const char *symname,
1287 struct module *mod,
1288 const s32 *crc)
1289{
1290 Elf_Shdr *sechdrs = info->sechdrs;
1291 unsigned int versindex = info->index.vers;
1292 unsigned int i, num_versions;
1293 struct modversion_info *versions;
1294
1295 /* Exporting module didn't supply crcs? OK, we're already tainted. */
1296 if (!crc)
1297 return 1;
1298
1299 /* No versions at all? modprobe --force does this. */
1300 if (versindex == 0)
1301 return try_to_force_load(mod, symname) == 0;
1302
1303 versions = (void *) sechdrs[versindex].sh_addr;
1304 num_versions = sechdrs[versindex].sh_size
1305 / sizeof(struct modversion_info);
1306
1307 for (i = 0; i < num_versions; i++) {
1308 u32 crcval;
1309
1310 if (strcmp(versions[i].name, symname) != 0)
1311 continue;
1312
1313 if (IS_ENABLED(CONFIG_MODULE_REL_CRCS))
1314 crcval = resolve_rel_crc(crc);
1315 else
1316 crcval = *crc;
1317 if (versions[i].crc == crcval)
1318 return 1;
1319 pr_debug("Found checksum %X vs module %lX\n",
1320 crcval, versions[i].crc);
1321 goto bad_version;
1322 }
1323
1324 /* Broken toolchain. Warn once, then let it go.. */
1325 pr_warn_once("%s: no symbol version for %s\n", info->name, symname);
1326 return 1;
1327
1328bad_version:
1329 pr_warn("%s: disagrees about version of symbol %s\n",
1330 info->name, symname);
1331 return 0;
1332}
1333
1334static inline int check_modstruct_version(const struct load_info *info,
1335 struct module *mod)
1336{
1337 const s32 *crc;
1338
1339 /*
1340 * Since this should be found in kernel (which can't be removed), no
1341 * locking is necessary -- use preempt_disable() to placate lockdep.
1342 */
1343 preempt_disable();
1344 if (!find_symbol(VMLINUX_SYMBOL_STR(module_layout), NULL,
1345 &crc, true, false)) {
1346 preempt_enable();
1347 BUG();
1348 }
1349 preempt_enable();
1350 return check_version(info, VMLINUX_SYMBOL_STR(module_layout),
1351 mod, crc);
1352}
1353
1354/* First part is kernel version, which we ignore if module has crcs. */
1355static inline int same_magic(const char *amagic, const char *bmagic,
1356 bool has_crcs)
1357{
1358 if (has_crcs) {
1359 amagic += strcspn(amagic, " ");
1360 bmagic += strcspn(bmagic, " ");
1361 }
1362 return strcmp(amagic, bmagic) == 0;
1363}
1364#else
1365static inline int check_version(const struct load_info *info,
1366 const char *symname,
1367 struct module *mod,
1368 const s32 *crc)
1369{
1370 return 1;
1371}
1372
1373static inline int check_modstruct_version(const struct load_info *info,
1374 struct module *mod)
1375{
1376 return 1;
1377}
1378
1379static inline int same_magic(const char *amagic, const char *bmagic,
1380 bool has_crcs)
1381{
1382 return strcmp(amagic, bmagic) == 0;
1383}
1384#endif /* CONFIG_MODVERSIONS */
1385
1386/* Resolve a symbol for this module. I.e. if we find one, record usage. */
1387static const struct kernel_symbol *resolve_symbol(struct module *mod,
1388 const struct load_info *info,
1389 const char *name,
1390 char ownername[])
1391{
1392 struct module *owner;
1393 const struct kernel_symbol *sym;
1394 const s32 *crc;
1395 int err;
1396
1397 /*
1398 * The module_mutex should not be a heavily contended lock;
1399 * if we get the occasional sleep here, we'll go an extra iteration
1400 * in the wait_event_interruptible(), which is harmless.
1401 */
1402 sched_annotate_sleep();
1403 mutex_lock(&module_mutex);
1404 sym = find_symbol(name, &owner, &crc,
1405 !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
1406 if (!sym)
1407 goto unlock;
1408
1409 if (!check_version(info, name, mod, crc)) {
1410 sym = ERR_PTR(-EINVAL);
1411 goto getname;
1412 }
1413
1414 err = ref_module(mod, owner);
1415 if (err) {
1416 sym = ERR_PTR(err);
1417 goto getname;
1418 }
1419
1420getname:
1421 /* We must make copy under the lock if we failed to get ref. */
1422 strncpy(ownername, module_name(owner), MODULE_NAME_LEN);
1423unlock:
1424 mutex_unlock(&module_mutex);
1425 return sym;
1426}
1427
1428static const struct kernel_symbol *
1429resolve_symbol_wait(struct module *mod,
1430 const struct load_info *info,
1431 const char *name)
1432{
1433 const struct kernel_symbol *ksym;
1434 char owner[MODULE_NAME_LEN];
1435
1436 if (wait_event_interruptible_timeout(module_wq,
1437 !IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
1438 || PTR_ERR(ksym) != -EBUSY,
1439 30 * HZ) <= 0) {
1440 pr_warn("%s: gave up waiting for init of module %s.\n",
1441 mod->name, owner);
1442 }
1443 return ksym;
1444}
1445
1446/*
1447 * /sys/module/foo/sections stuff
1448 * J. Corbet <corbet@lwn.net>
1449 */
1450#ifdef CONFIG_SYSFS
1451
1452#ifdef CONFIG_KALLSYMS
1453static inline bool sect_empty(const Elf_Shdr *sect)
1454{
1455 return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
1456}
1457
1458struct module_sect_attr {
1459 struct module_attribute mattr;
1460 char *name;
1461 unsigned long address;
1462};
1463
1464struct module_sect_attrs {
1465 struct attribute_group grp;
1466 unsigned int nsections;
1467 struct module_sect_attr attrs[0];
1468};
1469
1470static ssize_t module_sect_show(struct module_attribute *mattr,
1471 struct module_kobject *mk, char *buf)
1472{
1473 struct module_sect_attr *sattr =
1474 container_of(mattr, struct module_sect_attr, mattr);
1475 return sprintf(buf, "0x%px\n", kptr_restrict < 2 ?
1476 (void *)sattr->address : NULL);
1477}
1478
1479static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
1480{
1481 unsigned int section;
1482
1483 for (section = 0; section < sect_attrs->nsections; section++)
1484 kfree(sect_attrs->attrs[section].name);
1485 kfree(sect_attrs);
1486}
1487
1488static void add_sect_attrs(struct module *mod, const struct load_info *info)
1489{
1490 unsigned int nloaded = 0, i, size[2];
1491 struct module_sect_attrs *sect_attrs;
1492 struct module_sect_attr *sattr;
1493 struct attribute **gattr;
1494
1495 /* Count loaded sections and allocate structures */
1496 for (i = 0; i < info->hdr->e_shnum; i++)
1497 if (!sect_empty(&info->sechdrs[i]))
1498 nloaded++;
1499 size[0] = ALIGN(sizeof(*sect_attrs)
1500 + nloaded * sizeof(sect_attrs->attrs[0]),
1501 sizeof(sect_attrs->grp.attrs[0]));
1502 size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]);
1503 sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
1504 if (sect_attrs == NULL)
1505 return;
1506
1507 /* Setup section attributes. */
1508 sect_attrs->grp.name = "sections";
1509 sect_attrs->grp.attrs = (void *)sect_attrs + size[0];
1510
1511 sect_attrs->nsections = 0;
1512 sattr = §_attrs->attrs[0];
1513 gattr = §_attrs->grp.attrs[0];
1514 for (i = 0; i < info->hdr->e_shnum; i++) {
1515 Elf_Shdr *sec = &info->sechdrs[i];
1516 if (sect_empty(sec))
1517 continue;
1518 sattr->address = sec->sh_addr;
1519 sattr->name = kstrdup(info->secstrings + sec->sh_name,
1520 GFP_KERNEL);
1521 if (sattr->name == NULL)
1522 goto out;
1523 sect_attrs->nsections++;
1524 sysfs_attr_init(&sattr->mattr.attr);
1525 sattr->mattr.show = module_sect_show;
1526 sattr->mattr.store = NULL;
1527 sattr->mattr.attr.name = sattr->name;
1528 sattr->mattr.attr.mode = S_IRUSR;
1529 *(gattr++) = &(sattr++)->mattr.attr;
1530 }
1531 *gattr = NULL;
1532
1533 if (sysfs_create_group(&mod->mkobj.kobj, §_attrs->grp))
1534 goto out;
1535
1536 mod->sect_attrs = sect_attrs;
1537 return;
1538 out:
1539 free_sect_attrs(sect_attrs);
1540}
1541
1542static void remove_sect_attrs(struct module *mod)
1543{
1544 if (mod->sect_attrs) {
1545 sysfs_remove_group(&mod->mkobj.kobj,
1546 &mod->sect_attrs->grp);
1547 /* We are positive that no one is using any sect attrs
1548 * at this point. Deallocate immediately. */
1549 free_sect_attrs(mod->sect_attrs);
1550 mod->sect_attrs = NULL;
1551 }
1552}
1553
1554/*
1555 * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
1556 */
1557
1558struct module_notes_attrs {
1559 struct kobject *dir;
1560 unsigned int notes;
1561 struct bin_attribute attrs[0];
1562};
1563
1564static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
1565 struct bin_attribute *bin_attr,
1566 char *buf, loff_t pos, size_t count)
1567{
1568 /*
1569 * The caller checked the pos and count against our size.
1570 */
1571 memcpy(buf, bin_attr->private + pos, count);
1572 return count;
1573}
1574
1575static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
1576 unsigned int i)
1577{
1578 if (notes_attrs->dir) {
1579 while (i-- > 0)
1580 sysfs_remove_bin_file(notes_attrs->dir,
1581 ¬es_attrs->attrs[i]);
1582 kobject_put(notes_attrs->dir);
1583 }
1584 kfree(notes_attrs);
1585}
1586
1587static void add_notes_attrs(struct module *mod, const struct load_info *info)
1588{
1589 unsigned int notes, loaded, i;
1590 struct module_notes_attrs *notes_attrs;
1591 struct bin_attribute *nattr;
1592
1593 /* failed to create section attributes, so can't create notes */
1594 if (!mod->sect_attrs)
1595 return;
1596
1597 /* Count notes sections and allocate structures. */
1598 notes = 0;
1599 for (i = 0; i < info->hdr->e_shnum; i++)
1600 if (!sect_empty(&info->sechdrs[i]) &&
1601 (info->sechdrs[i].sh_type == SHT_NOTE))
1602 ++notes;
1603
1604 if (notes == 0)
1605 return;
1606
1607 notes_attrs = kzalloc(sizeof(*notes_attrs)
1608 + notes * sizeof(notes_attrs->attrs[0]),
1609 GFP_KERNEL);
1610 if (notes_attrs == NULL)
1611 return;
1612
1613 notes_attrs->notes = notes;
1614 nattr = ¬es_attrs->attrs[0];
1615 for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
1616 if (sect_empty(&info->sechdrs[i]))
1617 continue;
1618 if (info->sechdrs[i].sh_type == SHT_NOTE) {
1619 sysfs_bin_attr_init(nattr);
1620 nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
1621 nattr->attr.mode = S_IRUGO;
1622 nattr->size = info->sechdrs[i].sh_size;
1623 nattr->private = (void *) info->sechdrs[i].sh_addr;
1624 nattr->read = module_notes_read;
1625 ++nattr;
1626 }
1627 ++loaded;
1628 }
1629
1630 notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
1631 if (!notes_attrs->dir)
1632 goto out;
1633
1634 for (i = 0; i < notes; ++i)
1635 if (sysfs_create_bin_file(notes_attrs->dir,
1636 ¬es_attrs->attrs[i]))
1637 goto out;
1638
1639 mod->notes_attrs = notes_attrs;
1640 return;
1641
1642 out:
1643 free_notes_attrs(notes_attrs, i);
1644}
1645
1646static void remove_notes_attrs(struct module *mod)
1647{
1648 if (mod->notes_attrs)
1649 free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
1650}
1651
1652#else
1653
1654static inline void add_sect_attrs(struct module *mod,
1655 const struct load_info *info)
1656{
1657}
1658
1659static inline void remove_sect_attrs(struct module *mod)
1660{
1661}
1662
1663static inline void add_notes_attrs(struct module *mod,
1664 const struct load_info *info)
1665{
1666}
1667
1668static inline void remove_notes_attrs(struct module *mod)
1669{
1670}
1671#endif /* CONFIG_KALLSYMS */
1672
1673static void del_usage_links(struct module *mod)
1674{
1675#ifdef CONFIG_MODULE_UNLOAD
1676 struct module_use *use;
1677
1678 mutex_lock(&module_mutex);
1679 list_for_each_entry(use, &mod->target_list, target_list)
1680 sysfs_remove_link(use->target->holders_dir, mod->name);
1681 mutex_unlock(&module_mutex);
1682#endif
1683}
1684
1685static int add_usage_links(struct module *mod)
1686{
1687 int ret = 0;
1688#ifdef CONFIG_MODULE_UNLOAD
1689 struct module_use *use;
1690
1691 mutex_lock(&module_mutex);
1692 list_for_each_entry(use, &mod->target_list, target_list) {
1693 ret = sysfs_create_link(use->target->holders_dir,
1694 &mod->mkobj.kobj, mod->name);
1695 if (ret)
1696 break;
1697 }
1698 mutex_unlock(&module_mutex);
1699 if (ret)
1700 del_usage_links(mod);
1701#endif
1702 return ret;
1703}
1704
1705static int module_add_modinfo_attrs(struct module *mod)
1706{
1707 struct module_attribute *attr;
1708 struct module_attribute *temp_attr;
1709 int error = 0;
1710 int i;
1711
1712 mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
1713 (ARRAY_SIZE(modinfo_attrs) + 1)),
1714 GFP_KERNEL);
1715 if (!mod->modinfo_attrs)
1716 return -ENOMEM;
1717
1718 temp_attr = mod->modinfo_attrs;
1719 for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
1720 if (!attr->test || attr->test(mod)) {
1721 memcpy(temp_attr, attr, sizeof(*temp_attr));
1722 sysfs_attr_init(&temp_attr->attr);
1723 error = sysfs_create_file(&mod->mkobj.kobj,
1724 &temp_attr->attr);
1725 ++temp_attr;
1726 }
1727 }
1728 return error;
1729}
1730
1731static void module_remove_modinfo_attrs(struct module *mod)
1732{
1733 struct module_attribute *attr;
1734 int i;
1735
1736 for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
1737 /* pick a field to test for end of list */
1738 if (!attr->attr.name)
1739 break;
1740 sysfs_remove_file(&mod->mkobj.kobj, &attr->attr);
1741 if (attr->free)
1742 attr->free(mod);
1743 }
1744 kfree(mod->modinfo_attrs);
1745}
1746
1747static void mod_kobject_put(struct module *mod)
1748{
1749 DECLARE_COMPLETION_ONSTACK(c);
1750 mod->mkobj.kobj_completion = &c;
1751 kobject_put(&mod->mkobj.kobj);
1752 wait_for_completion(&c);
1753}
1754
1755static int mod_sysfs_init(struct module *mod)
1756{
1757 int err;
1758 struct kobject *kobj;
1759
1760 if (!module_sysfs_initialized) {
1761 pr_err("%s: module sysfs not initialized\n", mod->name);
1762 err = -EINVAL;
1763 goto out;
1764 }
1765
1766 kobj = kset_find_obj(module_kset, mod->name);
1767 if (kobj) {
1768 pr_err("%s: module is already loaded\n", mod->name);
1769 kobject_put(kobj);
1770 err = -EINVAL;
1771 goto out;
1772 }
1773
1774 mod->mkobj.mod = mod;
1775
1776 memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
1777 mod->mkobj.kobj.kset = module_kset;
1778 err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
1779 "%s", mod->name);
1780 if (err)
1781 mod_kobject_put(mod);
1782
1783 /* delay uevent until full sysfs population */
1784out:
1785 return err;
1786}
1787
1788static int mod_sysfs_setup(struct module *mod,
1789 const struct load_info *info,
1790 struct kernel_param *kparam,
1791 unsigned int num_params)
1792{
1793 int err;
1794
1795 err = mod_sysfs_init(mod);
1796 if (err)
1797 goto out;
1798
1799 mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1800 if (!mod->holders_dir) {
1801 err = -ENOMEM;
1802 goto out_unreg;
1803 }
1804
1805 err = module_param_sysfs_setup(mod, kparam, num_params);
1806 if (err)
1807 goto out_unreg_holders;
1808
1809 err = module_add_modinfo_attrs(mod);
1810 if (err)
1811 goto out_unreg_param;
1812
1813 err = add_usage_links(mod);
1814 if (err)
1815 goto out_unreg_modinfo_attrs;
1816
1817 add_sect_attrs(mod, info);
1818 add_notes_attrs(mod, info);
1819
1820 kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
1821 return 0;
1822
1823out_unreg_modinfo_attrs:
1824 module_remove_modinfo_attrs(mod);
1825out_unreg_param:
1826 module_param_sysfs_remove(mod);
1827out_unreg_holders:
1828 kobject_put(mod->holders_dir);
1829out_unreg:
1830 mod_kobject_put(mod);
1831out:
1832 return err;
1833}
1834
1835static void mod_sysfs_fini(struct module *mod)
1836{
1837 remove_notes_attrs(mod);
1838 remove_sect_attrs(mod);
1839 mod_kobject_put(mod);
1840}
1841
1842static void init_param_lock(struct module *mod)
1843{
1844 mutex_init(&mod->param_lock);
1845}
1846#else /* !CONFIG_SYSFS */
1847
1848static int mod_sysfs_setup(struct module *mod,
1849 const struct load_info *info,
1850 struct kernel_param *kparam,
1851 unsigned int num_params)
1852{
1853 return 0;
1854}
1855
1856static void mod_sysfs_fini(struct module *mod)
1857{
1858}
1859
1860static void module_remove_modinfo_attrs(struct module *mod)
1861{
1862}
1863
1864static void del_usage_links(struct module *mod)
1865{
1866}
1867
1868static void init_param_lock(struct module *mod)
1869{
1870}
1871#endif /* CONFIG_SYSFS */
1872
1873static void mod_sysfs_teardown(struct module *mod)
1874{
1875 del_usage_links(mod);
1876 module_remove_modinfo_attrs(mod);
1877 module_param_sysfs_remove(mod);
1878 kobject_put(mod->mkobj.drivers_dir);
1879 kobject_put(mod->holders_dir);
1880 mod_sysfs_fini(mod);
1881}
1882
1883#ifdef CONFIG_STRICT_MODULE_RWX
1884/*
1885 * LKM RO/NX protection: protect module's text/ro-data
1886 * from modification and any data from execution.
1887 *
1888 * General layout of module is:
1889 * [text] [read-only-data] [ro-after-init] [writable data]
1890 * text_size -----^ ^ ^ ^
1891 * ro_size ------------------------| | |
1892 * ro_after_init_size -----------------------------| |
1893 * size -----------------------------------------------------------|
1894 *
1895 * These values are always page-aligned (as is base)
1896 */
1897static void frob_text(const struct module_layout *layout,
1898 int (*set_memory)(unsigned long start, int num_pages))
1899{
1900 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1901 BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
1902 set_memory((unsigned long)layout->base,
1903 layout->text_size >> PAGE_SHIFT);
1904}
1905
1906static void frob_rodata(const struct module_layout *layout,
1907 int (*set_memory)(unsigned long start, int num_pages))
1908{
1909 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1910 BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
1911 BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
1912 set_memory((unsigned long)layout->base + layout->text_size,
1913 (layout->ro_size - layout->text_size) >> PAGE_SHIFT);
1914}
1915
1916static void frob_ro_after_init(const struct module_layout *layout,
1917 int (*set_memory)(unsigned long start, int num_pages))
1918{
1919 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1920 BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
1921 BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
1922 set_memory((unsigned long)layout->base + layout->ro_size,
1923 (layout->ro_after_init_size - layout->ro_size) >> PAGE_SHIFT);
1924}
1925
1926static void frob_writable_data(const struct module_layout *layout,
1927 int (*set_memory)(unsigned long start, int num_pages))
1928{
1929 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1930 BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
1931 BUG_ON((unsigned long)layout->size & (PAGE_SIZE-1));
1932 set_memory((unsigned long)layout->base + layout->ro_after_init_size,
1933 (layout->size - layout->ro_after_init_size) >> PAGE_SHIFT);
1934}
1935
1936/* livepatching wants to disable read-only so it can frob module. */
1937void module_disable_ro(const struct module *mod)
1938{
1939 if (!rodata_enabled)
1940 return;
1941
1942 frob_text(&mod->core_layout, set_memory_rw);
1943 frob_rodata(&mod->core_layout, set_memory_rw);
1944 frob_ro_after_init(&mod->core_layout, set_memory_rw);
1945 frob_text(&mod->init_layout, set_memory_rw);
1946 frob_rodata(&mod->init_layout, set_memory_rw);
1947}
1948
1949void module_enable_ro(const struct module *mod, bool after_init)
1950{
1951 if (!rodata_enabled)
1952 return;
1953
1954 frob_text(&mod->core_layout, set_memory_ro);
1955 frob_rodata(&mod->core_layout, set_memory_ro);
1956 frob_text(&mod->init_layout, set_memory_ro);
1957 frob_rodata(&mod->init_layout, set_memory_ro);
1958
1959 if (after_init)
1960 frob_ro_after_init(&mod->core_layout, set_memory_ro);
1961}
1962
1963static void module_enable_nx(const struct module *mod)
1964{
1965 frob_rodata(&mod->core_layout, set_memory_nx);
1966 frob_ro_after_init(&mod->core_layout, set_memory_nx);
1967 frob_writable_data(&mod->core_layout, set_memory_nx);
1968 frob_rodata(&mod->init_layout, set_memory_nx);
1969 frob_writable_data(&mod->init_layout, set_memory_nx);
1970}
1971
1972static void module_disable_nx(const struct module *mod)
1973{
1974 frob_rodata(&mod->core_layout, set_memory_x);
1975 frob_ro_after_init(&mod->core_layout, set_memory_x);
1976 frob_writable_data(&mod->core_layout, set_memory_x);
1977 frob_rodata(&mod->init_layout, set_memory_x);
1978 frob_writable_data(&mod->init_layout, set_memory_x);
1979}
1980
1981/* Iterate through all modules and set each module's text as RW */
1982void set_all_modules_text_rw(void)
1983{
1984 struct module *mod;
1985
1986 if (!rodata_enabled)
1987 return;
1988
1989 mutex_lock(&module_mutex);
1990 list_for_each_entry_rcu(mod, &modules, list) {
1991 if (mod->state == MODULE_STATE_UNFORMED)
1992 continue;
1993
1994 frob_text(&mod->core_layout, set_memory_rw);
1995 frob_text(&mod->init_layout, set_memory_rw);
1996 }
1997 mutex_unlock(&module_mutex);
1998}
1999
2000/* Iterate through all modules and set each module's text as RO */
2001void set_all_modules_text_ro(void)
2002{
2003 struct module *mod;
2004
2005 if (!rodata_enabled)
2006 return;
2007
2008 mutex_lock(&module_mutex);
2009 list_for_each_entry_rcu(mod, &modules, list) {
2010 /*
2011 * Ignore going modules since it's possible that ro
2012 * protection has already been disabled, otherwise we'll
2013 * run into protection faults at module deallocation.
2014 */
2015 if (mod->state == MODULE_STATE_UNFORMED ||
2016 mod->state == MODULE_STATE_GOING)
2017 continue;
2018
2019 frob_text(&mod->core_layout, set_memory_ro);
2020 frob_text(&mod->init_layout, set_memory_ro);
2021 }
2022 mutex_unlock(&module_mutex);
2023}
2024
2025static void disable_ro_nx(const struct module_layout *layout)
2026{
2027 if (rodata_enabled) {
2028 frob_text(layout, set_memory_rw);
2029 frob_rodata(layout, set_memory_rw);
2030 frob_ro_after_init(layout, set_memory_rw);
2031 }
2032 frob_rodata(layout, set_memory_x);
2033 frob_ro_after_init(layout, set_memory_x);
2034 frob_writable_data(layout, set_memory_x);
2035}
2036
2037#else
2038static void disable_ro_nx(const struct module_layout *layout) { }
2039static void module_enable_nx(const struct module *mod) { }
2040static void module_disable_nx(const struct module *mod) { }
2041#endif
2042
2043#ifdef CONFIG_LIVEPATCH
2044/*
2045 * Persist Elf information about a module. Copy the Elf header,
2046 * section header table, section string table, and symtab section
2047 * index from info to mod->klp_info.
2048 */
2049static int copy_module_elf(struct module *mod, struct load_info *info)
2050{
2051 unsigned int size, symndx;
2052 int ret;
2053
2054 size = sizeof(*mod->klp_info);
2055 mod->klp_info = kmalloc(size, GFP_KERNEL);
2056 if (mod->klp_info == NULL)
2057 return -ENOMEM;
2058
2059 /* Elf header */
2060 size = sizeof(mod->klp_info->hdr);
2061 memcpy(&mod->klp_info->hdr, info->hdr, size);
2062
2063 /* Elf section header table */
2064 size = sizeof(*info->sechdrs) * info->hdr->e_shnum;
2065 mod->klp_info->sechdrs = kmalloc(size, GFP_KERNEL);
2066 if (mod->klp_info->sechdrs == NULL) {
2067 ret = -ENOMEM;
2068 goto free_info;
2069 }
2070 memcpy(mod->klp_info->sechdrs, info->sechdrs, size);
2071
2072 /* Elf section name string table */
2073 size = info->sechdrs[info->hdr->e_shstrndx].sh_size;
2074 mod->klp_info->secstrings = kmalloc(size, GFP_KERNEL);
2075 if (mod->klp_info->secstrings == NULL) {
2076 ret = -ENOMEM;
2077 goto free_sechdrs;
2078 }
2079 memcpy(mod->klp_info->secstrings, info->secstrings, size);
2080
2081 /* Elf symbol section index */
2082 symndx = info->index.sym;
2083 mod->klp_info->symndx = symndx;
2084
2085 /*
2086 * For livepatch modules, core_kallsyms.symtab is a complete
2087 * copy of the original symbol table. Adjust sh_addr to point
2088 * to core_kallsyms.symtab since the copy of the symtab in module
2089 * init memory is freed at the end of do_init_module().
2090 */
2091 mod->klp_info->sechdrs[symndx].sh_addr = \
2092 (unsigned long) mod->core_kallsyms.symtab;
2093
2094 return 0;
2095
2096free_sechdrs:
2097 kfree(mod->klp_info->sechdrs);
2098free_info:
2099 kfree(mod->klp_info);
2100 return ret;
2101}
2102
2103static void free_module_elf(struct module *mod)
2104{
2105 kfree(mod->klp_info->sechdrs);
2106 kfree(mod->klp_info->secstrings);
2107 kfree(mod->klp_info);
2108}
2109#else /* !CONFIG_LIVEPATCH */
2110static int copy_module_elf(struct module *mod, struct load_info *info)
2111{
2112 return 0;
2113}
2114
2115static void free_module_elf(struct module *mod)
2116{
2117}
2118#endif /* CONFIG_LIVEPATCH */
2119
2120void __weak module_memfree(void *module_region)
2121{
2122 vfree(module_region);
2123}
2124
2125void __weak module_arch_cleanup(struct module *mod)
2126{
2127}
2128
2129void __weak module_arch_freeing_init(struct module *mod)
2130{
2131}
2132
2133/* Free a module, remove from lists, etc. */
2134static void free_module(struct module *mod)
2135{
2136 trace_module_free(mod);
2137
2138 mod_sysfs_teardown(mod);
2139
2140 /* We leave it in list to prevent duplicate loads, but make sure
2141 * that noone uses it while it's being deconstructed. */
2142 mutex_lock(&module_mutex);
2143 mod->state = MODULE_STATE_UNFORMED;
2144 mutex_unlock(&module_mutex);
2145
2146 /* Remove dynamic debug info */
2147 ddebug_remove_module(mod->name);
2148
2149 /* Arch-specific cleanup. */
2150 module_arch_cleanup(mod);
2151
2152 /* Module unload stuff */
2153 module_unload_free(mod);
2154
2155 /* Free any allocated parameters. */
2156 destroy_params(mod->kp, mod->num_kp);
2157
2158 if (is_livepatch_module(mod))
2159 free_module_elf(mod);
2160
2161 /* Now we can delete it from the lists */
2162 mutex_lock(&module_mutex);
2163 /* Unlink carefully: kallsyms could be walking list. */
2164 list_del_rcu(&mod->list);
2165 mod_tree_remove(mod);
2166 /* Remove this module from bug list, this uses list_del_rcu */
2167 module_bug_cleanup(mod);
2168 /* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */
2169 synchronize_sched();
2170 mutex_unlock(&module_mutex);
2171
2172 /* This may be empty, but that's OK */
2173 disable_ro_nx(&mod->init_layout);
2174 module_arch_freeing_init(mod);
2175 module_memfree(mod->init_layout.base);
2176 kfree(mod->args);
2177 percpu_modfree(mod);
2178
2179 /* Free lock-classes; relies on the preceding sync_rcu(). */
2180 lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
2181
2182 /* Finally, free the core (containing the module structure) */
2183 disable_ro_nx(&mod->core_layout);
2184 module_memfree(mod->core_layout.base);
2185}
2186
2187void *__symbol_get(const char *symbol)
2188{
2189 struct module *owner;
2190 const struct kernel_symbol *sym;
2191
2192 preempt_disable();
2193 sym = find_symbol(symbol, &owner, NULL, true, true);
2194 if (sym && strong_try_module_get(owner))
2195 sym = NULL;
2196 preempt_enable();
2197
2198 return sym ? (void *)sym->value : NULL;
2199}
2200EXPORT_SYMBOL_GPL(__symbol_get);
2201
2202/*
2203 * Ensure that an exported symbol [global namespace] does not already exist
2204 * in the kernel or in some other module's exported symbol table.
2205 *
2206 * You must hold the module_mutex.
2207 */
2208static int verify_export_symbols(struct module *mod)
2209{
2210 unsigned int i;
2211 struct module *owner;
2212 const struct kernel_symbol *s;
2213 struct {
2214 const struct kernel_symbol *sym;
2215 unsigned int num;
2216 } arr[] = {
2217 { mod->syms, mod->num_syms },
2218 { mod->gpl_syms, mod->num_gpl_syms },
2219 { mod->gpl_future_syms, mod->num_gpl_future_syms },
2220#ifdef CONFIG_UNUSED_SYMBOLS
2221 { mod->unused_syms, mod->num_unused_syms },
2222 { mod->unused_gpl_syms, mod->num_unused_gpl_syms },
2223#endif
2224 };
2225
2226 for (i = 0; i < ARRAY_SIZE(arr); i++) {
2227 for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
2228 if (find_symbol(s->name, &owner, NULL, true, false)) {
2229 pr_err("%s: exports duplicate symbol %s"
2230 " (owned by %s)\n",
2231 mod->name, s->name, module_name(owner));
2232 return -ENOEXEC;
2233 }
2234 }
2235 }
2236 return 0;
2237}
2238
2239/* Change all symbols so that st_value encodes the pointer directly. */
2240static int simplify_symbols(struct module *mod, const struct load_info *info)
2241{
2242 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2243 Elf_Sym *sym = (void *)symsec->sh_addr;
2244 unsigned long secbase;
2245 unsigned int i;
2246 int ret = 0;
2247 const struct kernel_symbol *ksym;
2248
2249 for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
2250 const char *name = info->strtab + sym[i].st_name;
2251
2252 switch (sym[i].st_shndx) {
2253 case SHN_COMMON:
2254 /* Ignore common symbols */
2255 if (!strncmp(name, "__gnu_lto", 9))
2256 break;
2257
2258 /* We compiled with -fno-common. These are not
2259 supposed to happen. */
2260 pr_debug("Common symbol: %s\n", name);
2261 pr_warn("%s: please compile with -fno-common\n",
2262 mod->name);
2263 ret = -ENOEXEC;
2264 break;
2265
2266 case SHN_ABS:
2267 /* Don't need to do anything */
2268 pr_debug("Absolute symbol: 0x%08lx\n",
2269 (long)sym[i].st_value);
2270 break;
2271
2272 case SHN_LIVEPATCH:
2273 /* Livepatch symbols are resolved by livepatch */
2274 break;
2275
2276 case SHN_UNDEF:
2277 ksym = resolve_symbol_wait(mod, info, name);
2278 /* Ok if resolved. */
2279 if (ksym && !IS_ERR(ksym)) {
2280 sym[i].st_value = ksym->value;
2281 break;
2282 }
2283
2284 /* Ok if weak. */
2285 if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
2286 break;
2287
2288 pr_warn("%s: Unknown symbol %s (err %li)\n",
2289 mod->name, name, PTR_ERR(ksym));
2290 ret = PTR_ERR(ksym) ?: -ENOENT;
2291 break;
2292
2293 default:
2294 /* Divert to percpu allocation if a percpu var. */
2295 if (sym[i].st_shndx == info->index.pcpu)
2296 secbase = (unsigned long)mod_percpu(mod);
2297 else
2298 secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
2299 sym[i].st_value += secbase;
2300 break;
2301 }
2302 }
2303
2304 return ret;
2305}
2306
2307static int apply_relocations(struct module *mod, const struct load_info *info)
2308{
2309 unsigned int i;
2310 int err = 0;
2311
2312 /* Now do relocations. */
2313 for (i = 1; i < info->hdr->e_shnum; i++) {
2314 unsigned int infosec = info->sechdrs[i].sh_info;
2315
2316 /* Not a valid relocation section? */
2317 if (infosec >= info->hdr->e_shnum)
2318 continue;
2319
2320 /* Don't bother with non-allocated sections */
2321 if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
2322 continue;
2323
2324 /* Livepatch relocation sections are applied by livepatch */
2325 if (info->sechdrs[i].sh_flags & SHF_RELA_LIVEPATCH)
2326 continue;
2327
2328 if (info->sechdrs[i].sh_type == SHT_REL)
2329 err = apply_relocate(info->sechdrs, info->strtab,
2330 info->index.sym, i, mod);
2331 else if (info->sechdrs[i].sh_type == SHT_RELA)
2332 err = apply_relocate_add(info->sechdrs, info->strtab,
2333 info->index.sym, i, mod);
2334 if (err < 0)
2335 break;
2336 }
2337 return err;
2338}
2339
2340/* Additional bytes needed by arch in front of individual sections */
2341unsigned int __weak arch_mod_section_prepend(struct module *mod,
2342 unsigned int section)
2343{
2344 /* default implementation just returns zero */
2345 return 0;
2346}
2347
2348/* Update size with this section: return offset. */
2349static long get_offset(struct module *mod, unsigned int *size,
2350 Elf_Shdr *sechdr, unsigned int section)
2351{
2352 long ret;
2353
2354 *size += arch_mod_section_prepend(mod, section);
2355 ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
2356 *size = ret + sechdr->sh_size;
2357 return ret;
2358}
2359
2360/* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
2361 might -- code, read-only data, read-write data, small data. Tally
2362 sizes, and place the offsets into sh_entsize fields: high bit means it
2363 belongs in init. */
2364static void layout_sections(struct module *mod, struct load_info *info)
2365{
2366 static unsigned long const masks[][2] = {
2367 /* NOTE: all executable code must be the first section
2368 * in this array; otherwise modify the text_size
2369 * finder in the two loops below */
2370 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
2371 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
2372 { SHF_RO_AFTER_INIT | SHF_ALLOC, ARCH_SHF_SMALL },
2373 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
2374 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
2375 };
2376 unsigned int m, i;
2377
2378 for (i = 0; i < info->hdr->e_shnum; i++)
2379 info->sechdrs[i].sh_entsize = ~0UL;
2380
2381 pr_debug("Core section allocation order:\n");
2382 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2383 for (i = 0; i < info->hdr->e_shnum; ++i) {
2384 Elf_Shdr *s = &info->sechdrs[i];
2385 const char *sname = info->secstrings + s->sh_name;
2386
2387 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2388 || (s->sh_flags & masks[m][1])
2389 || s->sh_entsize != ~0UL
2390 || strstarts(sname, ".init"))
2391 continue;
2392 s->sh_entsize = get_offset(mod, &mod->core_layout.size, s, i);
2393 pr_debug("\t%s\n", sname);
2394 }
2395 switch (m) {
2396 case 0: /* executable */
2397 mod->core_layout.size = debug_align(mod->core_layout.size);
2398 mod->core_layout.text_size = mod->core_layout.size;
2399 break;
2400 case 1: /* RO: text and ro-data */
2401 mod->core_layout.size = debug_align(mod->core_layout.size);
2402 mod->core_layout.ro_size = mod->core_layout.size;
2403 break;
2404 case 2: /* RO after init */
2405 mod->core_layout.size = debug_align(mod->core_layout.size);
2406 mod->core_layout.ro_after_init_size = mod->core_layout.size;
2407 break;
2408 case 4: /* whole core */
2409 mod->core_layout.size = debug_align(mod->core_layout.size);
2410 break;
2411 }
2412 }
2413
2414 pr_debug("Init section allocation order:\n");
2415 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2416 for (i = 0; i < info->hdr->e_shnum; ++i) {
2417 Elf_Shdr *s = &info->sechdrs[i];
2418 const char *sname = info->secstrings + s->sh_name;
2419
2420 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2421 || (s->sh_flags & masks[m][1])
2422 || s->sh_entsize != ~0UL
2423 || !strstarts(sname, ".init"))
2424 continue;
2425 s->sh_entsize = (get_offset(mod, &mod->init_layout.size, s, i)
2426 | INIT_OFFSET_MASK);
2427 pr_debug("\t%s\n", sname);
2428 }
2429 switch (m) {
2430 case 0: /* executable */
2431 mod->init_layout.size = debug_align(mod->init_layout.size);
2432 mod->init_layout.text_size = mod->init_layout.size;
2433 break;
2434 case 1: /* RO: text and ro-data */
2435 mod->init_layout.size = debug_align(mod->init_layout.size);
2436 mod->init_layout.ro_size = mod->init_layout.size;
2437 break;
2438 case 2:
2439 /*
2440 * RO after init doesn't apply to init_layout (only
2441 * core_layout), so it just takes the value of ro_size.
2442 */
2443 mod->init_layout.ro_after_init_size = mod->init_layout.ro_size;
2444 break;
2445 case 4: /* whole init */
2446 mod->init_layout.size = debug_align(mod->init_layout.size);
2447 break;
2448 }
2449 }
2450}
2451
2452static void set_license(struct module *mod, const char *license)
2453{
2454 if (!license)
2455 license = "unspecified";
2456
2457 if (!license_is_gpl_compatible(license)) {
2458 if (!test_taint(TAINT_PROPRIETARY_MODULE))
2459 pr_warn("%s: module license '%s' taints kernel.\n",
2460 mod->name, license);
2461 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2462 LOCKDEP_NOW_UNRELIABLE);
2463 }
2464}
2465
2466/* Parse tag=value strings from .modinfo section */
2467static char *next_string(char *string, unsigned long *secsize)
2468{
2469 /* Skip non-zero chars */
2470 while (string[0]) {
2471 string++;
2472 if ((*secsize)-- <= 1)
2473 return NULL;
2474 }
2475
2476 /* Skip any zero padding. */
2477 while (!string[0]) {
2478 string++;
2479 if ((*secsize)-- <= 1)
2480 return NULL;
2481 }
2482 return string;
2483}
2484
2485static char *get_modinfo(struct load_info *info, const char *tag)
2486{
2487 char *p;
2488 unsigned int taglen = strlen(tag);
2489 Elf_Shdr *infosec = &info->sechdrs[info->index.info];
2490 unsigned long size = infosec->sh_size;
2491
2492 for (p = (char *)infosec->sh_addr; p; p = next_string(p, &size)) {
2493 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
2494 return p + taglen + 1;
2495 }
2496 return NULL;
2497}
2498
2499static void setup_modinfo(struct module *mod, struct load_info *info)
2500{
2501 struct module_attribute *attr;
2502 int i;
2503
2504 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2505 if (attr->setup)
2506 attr->setup(mod, get_modinfo(info, attr->attr.name));
2507 }
2508}
2509
2510static void free_modinfo(struct module *mod)
2511{
2512 struct module_attribute *attr;
2513 int i;
2514
2515 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2516 if (attr->free)
2517 attr->free(mod);
2518 }
2519}
2520
2521#ifdef CONFIG_KALLSYMS
2522
2523/* lookup symbol in given range of kernel_symbols */
2524static const struct kernel_symbol *lookup_symbol(const char *name,
2525 const struct kernel_symbol *start,
2526 const struct kernel_symbol *stop)
2527{
2528 return bsearch(name, start, stop - start,
2529 sizeof(struct kernel_symbol), cmp_name);
2530}
2531
2532static int is_exported(const char *name, unsigned long value,
2533 const struct module *mod)
2534{
2535 const struct kernel_symbol *ks;
2536 if (!mod)
2537 ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
2538 else
2539 ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
2540 return ks != NULL && ks->value == value;
2541}
2542
2543/* As per nm */
2544static char elf_type(const Elf_Sym *sym, const struct load_info *info)
2545{
2546 const Elf_Shdr *sechdrs = info->sechdrs;
2547
2548 if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
2549 if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
2550 return 'v';
2551 else
2552 return 'w';
2553 }
2554 if (sym->st_shndx == SHN_UNDEF)
2555 return 'U';
2556 if (sym->st_shndx == SHN_ABS || sym->st_shndx == info->index.pcpu)
2557 return 'a';
2558 if (sym->st_shndx >= SHN_LORESERVE)
2559 return '?';
2560 if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
2561 return 't';
2562 if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
2563 && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
2564 if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
2565 return 'r';
2566 else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2567 return 'g';
2568 else
2569 return 'd';
2570 }
2571 if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
2572 if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2573 return 's';
2574 else
2575 return 'b';
2576 }
2577 if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
2578 ".debug")) {
2579 return 'n';
2580 }
2581 return '?';
2582}
2583
2584static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
2585 unsigned int shnum, unsigned int pcpundx)
2586{
2587 const Elf_Shdr *sec;
2588
2589 if (src->st_shndx == SHN_UNDEF
2590 || src->st_shndx >= shnum
2591 || !src->st_name)
2592 return false;
2593
2594#ifdef CONFIG_KALLSYMS_ALL
2595 if (src->st_shndx == pcpundx)
2596 return true;
2597#endif
2598
2599 sec = sechdrs + src->st_shndx;
2600 if (!(sec->sh_flags & SHF_ALLOC)
2601#ifndef CONFIG_KALLSYMS_ALL
2602 || !(sec->sh_flags & SHF_EXECINSTR)
2603#endif
2604 || (sec->sh_entsize & INIT_OFFSET_MASK))
2605 return false;
2606
2607 return true;
2608}
2609
2610/*
2611 * We only allocate and copy the strings needed by the parts of symtab
2612 * we keep. This is simple, but has the effect of making multiple
2613 * copies of duplicates. We could be more sophisticated, see
2614 * linux-kernel thread starting with
2615 * <73defb5e4bca04a6431392cc341112b1@localhost>.
2616 */
2617static void layout_symtab(struct module *mod, struct load_info *info)
2618{
2619 Elf_Shdr *symsect = info->sechdrs + info->index.sym;
2620 Elf_Shdr *strsect = info->sechdrs + info->index.str;
2621 const Elf_Sym *src;
2622 unsigned int i, nsrc, ndst, strtab_size = 0;
2623
2624 /* Put symbol section at end of init part of module. */
2625 symsect->sh_flags |= SHF_ALLOC;
2626 symsect->sh_entsize = get_offset(mod, &mod->init_layout.size, symsect,
2627 info->index.sym) | INIT_OFFSET_MASK;
2628 pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
2629
2630 src = (void *)info->hdr + symsect->sh_offset;
2631 nsrc = symsect->sh_size / sizeof(*src);
2632
2633 /* Compute total space required for the core symbols' strtab. */
2634 for (ndst = i = 0; i < nsrc; i++) {
2635 if (i == 0 || is_livepatch_module(mod) ||
2636 is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
2637 info->index.pcpu)) {
2638 strtab_size += strlen(&info->strtab[src[i].st_name])+1;
2639 ndst++;
2640 }
2641 }
2642
2643 /* Append room for core symbols at end of core part. */
2644 info->symoffs = ALIGN(mod->core_layout.size, symsect->sh_addralign ?: 1);
2645 info->stroffs = mod->core_layout.size = info->symoffs + ndst * sizeof(Elf_Sym);
2646 mod->core_layout.size += strtab_size;
2647 mod->core_layout.size = debug_align(mod->core_layout.size);
2648
2649 /* Put string table section at end of init part of module. */
2650 strsect->sh_flags |= SHF_ALLOC;
2651 strsect->sh_entsize = get_offset(mod, &mod->init_layout.size, strsect,
2652 info->index.str) | INIT_OFFSET_MASK;
2653 pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
2654
2655 /* We'll tack temporary mod_kallsyms on the end. */
2656 mod->init_layout.size = ALIGN(mod->init_layout.size,
2657 __alignof__(struct mod_kallsyms));
2658 info->mod_kallsyms_init_off = mod->init_layout.size;
2659 mod->init_layout.size += sizeof(struct mod_kallsyms);
2660 mod->init_layout.size = debug_align(mod->init_layout.size);
2661}
2662
2663/*
2664 * We use the full symtab and strtab which layout_symtab arranged to
2665 * be appended to the init section. Later we switch to the cut-down
2666 * core-only ones.
2667 */
2668static void add_kallsyms(struct module *mod, const struct load_info *info)
2669{
2670 unsigned int i, ndst;
2671 const Elf_Sym *src;
2672 Elf_Sym *dst;
2673 char *s;
2674 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2675
2676 /* Set up to point into init section. */
2677 mod->kallsyms = mod->init_layout.base + info->mod_kallsyms_init_off;
2678
2679 mod->kallsyms->symtab = (void *)symsec->sh_addr;
2680 mod->kallsyms->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
2681 /* Make sure we get permanent strtab: don't use info->strtab. */
2682 mod->kallsyms->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
2683
2684 /* Set types up while we still have access to sections. */
2685 for (i = 0; i < mod->kallsyms->num_symtab; i++)
2686 mod->kallsyms->symtab[i].st_info
2687 = elf_type(&mod->kallsyms->symtab[i], info);
2688
2689 /* Now populate the cut down core kallsyms for after init. */
2690 mod->core_kallsyms.symtab = dst = mod->core_layout.base + info->symoffs;
2691 mod->core_kallsyms.strtab = s = mod->core_layout.base + info->stroffs;
2692 src = mod->kallsyms->symtab;
2693 for (ndst = i = 0; i < mod->kallsyms->num_symtab; i++) {
2694 if (i == 0 || is_livepatch_module(mod) ||
2695 is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
2696 info->index.pcpu)) {
2697 dst[ndst] = src[i];
2698 dst[ndst++].st_name = s - mod->core_kallsyms.strtab;
2699 s += strlcpy(s, &mod->kallsyms->strtab[src[i].st_name],
2700 KSYM_NAME_LEN) + 1;
2701 }
2702 }
2703 mod->core_kallsyms.num_symtab = ndst;
2704}
2705#else
2706static inline void layout_symtab(struct module *mod, struct load_info *info)
2707{
2708}
2709
2710static void add_kallsyms(struct module *mod, const struct load_info *info)
2711{
2712}
2713#endif /* CONFIG_KALLSYMS */
2714
2715static void dynamic_debug_setup(struct module *mod, struct _ddebug *debug, unsigned int num)
2716{
2717 if (!debug)
2718 return;
2719#ifdef CONFIG_DYNAMIC_DEBUG
2720 if (ddebug_add_module(debug, num, mod->name))
2721 pr_err("dynamic debug error adding module: %s\n",
2722 debug->modname);
2723#endif
2724}
2725
2726static void dynamic_debug_remove(struct module *mod, struct _ddebug *debug)
2727{
2728 if (debug)
2729 ddebug_remove_module(mod->name);
2730}
2731
2732void * __weak module_alloc(unsigned long size)
2733{
2734 return vmalloc_exec(size);
2735}
2736
2737#ifdef CONFIG_DEBUG_KMEMLEAK
2738static void kmemleak_load_module(const struct module *mod,
2739 const struct load_info *info)
2740{
2741 unsigned int i;
2742
2743 /* only scan the sections containing data */
2744 kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
2745
2746 for (i = 1; i < info->hdr->e_shnum; i++) {
2747 /* Scan all writable sections that's not executable */
2748 if (!(info->sechdrs[i].sh_flags & SHF_ALLOC) ||
2749 !(info->sechdrs[i].sh_flags & SHF_WRITE) ||
2750 (info->sechdrs[i].sh_flags & SHF_EXECINSTR))
2751 continue;
2752
2753 kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
2754 info->sechdrs[i].sh_size, GFP_KERNEL);
2755 }
2756}
2757#else
2758static inline void kmemleak_load_module(const struct module *mod,
2759 const struct load_info *info)
2760{
2761}
2762#endif
2763
2764#ifdef CONFIG_MODULE_SIG
2765static int module_sig_check(struct load_info *info, int flags)
2766{
2767 int err = -ENOKEY;
2768 const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
2769 const void *mod = info->hdr;
2770
2771 /*
2772 * Require flags == 0, as a module with version information
2773 * removed is no longer the module that was signed
2774 */
2775 if (flags == 0 &&
2776 info->len > markerlen &&
2777 memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
2778 /* We truncate the module to discard the signature */
2779 info->len -= markerlen;
2780 err = mod_verify_sig(mod, &info->len);
2781 }
2782
2783 if (!err) {
2784 info->sig_ok = true;
2785 return 0;
2786 }
2787
2788 /* Not having a signature is only an error if we're strict. */
2789 if (err == -ENOKEY && !sig_enforce)
2790 err = 0;
2791
2792 return err;
2793}
2794#else /* !CONFIG_MODULE_SIG */
2795static int module_sig_check(struct load_info *info, int flags)
2796{
2797 return 0;
2798}
2799#endif /* !CONFIG_MODULE_SIG */
2800
2801/* Sanity checks against invalid binaries, wrong arch, weird elf version. */
2802static int elf_header_check(struct load_info *info)
2803{
2804 if (info->len < sizeof(*(info->hdr)))
2805 return -ENOEXEC;
2806
2807 if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0
2808 || info->hdr->e_type != ET_REL
2809 || !elf_check_arch(info->hdr)
2810 || info->hdr->e_shentsize != sizeof(Elf_Shdr))
2811 return -ENOEXEC;
2812
2813 if (info->hdr->e_shoff >= info->len
2814 || (info->hdr->e_shnum * sizeof(Elf_Shdr) >
2815 info->len - info->hdr->e_shoff))
2816 return -ENOEXEC;
2817
2818 return 0;
2819}
2820
2821#define COPY_CHUNK_SIZE (16*PAGE_SIZE)
2822
2823static int copy_chunked_from_user(void *dst, const void __user *usrc, unsigned long len)
2824{
2825 do {
2826 unsigned long n = min(len, COPY_CHUNK_SIZE);
2827
2828 if (copy_from_user(dst, usrc, n) != 0)
2829 return -EFAULT;
2830 cond_resched();
2831 dst += n;
2832 usrc += n;
2833 len -= n;
2834 } while (len);
2835 return 0;
2836}
2837
2838#ifdef CONFIG_LIVEPATCH
2839static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
2840{
2841 if (get_modinfo(info, "livepatch")) {
2842 mod->klp = true;
2843 add_taint_module(mod, TAINT_LIVEPATCH, LOCKDEP_STILL_OK);
2844 pr_notice_once("%s: tainting kernel with TAINT_LIVEPATCH\n",
2845 mod->name);
2846 }
2847
2848 return 0;
2849}
2850#else /* !CONFIG_LIVEPATCH */
2851static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
2852{
2853 if (get_modinfo(info, "livepatch")) {
2854 pr_err("%s: module is marked as livepatch module, but livepatch support is disabled",
2855 mod->name);
2856 return -ENOEXEC;
2857 }
2858
2859 return 0;
2860}
2861#endif /* CONFIG_LIVEPATCH */
2862
2863static void check_modinfo_retpoline(struct module *mod, struct load_info *info)
2864{
2865 if (retpoline_module_ok(get_modinfo(info, "retpoline")))
2866 return;
2867
2868 pr_warn("%s: loading module not compiled with retpoline compiler.\n",
2869 mod->name);
2870}
2871
2872/* Sets info->hdr and info->len. */
2873static int copy_module_from_user(const void __user *umod, unsigned long len,
2874 struct load_info *info)
2875{
2876 int err;
2877
2878 info->len = len;
2879 if (info->len < sizeof(*(info->hdr)))
2880 return -ENOEXEC;
2881
2882 err = security_kernel_read_file(NULL, READING_MODULE);
2883 if (err)
2884 return err;
2885
2886 /* Suck in entire file: we'll want most of it. */
2887 info->hdr = __vmalloc(info->len,
2888 GFP_KERNEL | __GFP_NOWARN, PAGE_KERNEL);
2889 if (!info->hdr)
2890 return -ENOMEM;
2891
2892 if (copy_chunked_from_user(info->hdr, umod, info->len) != 0) {
2893 vfree(info->hdr);
2894 return -EFAULT;
2895 }
2896
2897 return 0;
2898}
2899
2900static void free_copy(struct load_info *info)
2901{
2902 vfree(info->hdr);
2903}
2904
2905static int rewrite_section_headers(struct load_info *info, int flags)
2906{
2907 unsigned int i;
2908
2909 /* This should always be true, but let's be sure. */
2910 info->sechdrs[0].sh_addr = 0;
2911
2912 for (i = 1; i < info->hdr->e_shnum; i++) {
2913 Elf_Shdr *shdr = &info->sechdrs[i];
2914 if (shdr->sh_type != SHT_NOBITS
2915 && info->len < shdr->sh_offset + shdr->sh_size) {
2916 pr_err("Module len %lu truncated\n", info->len);
2917 return -ENOEXEC;
2918 }
2919
2920 /* Mark all sections sh_addr with their address in the
2921 temporary image. */
2922 shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
2923
2924#ifndef CONFIG_MODULE_UNLOAD
2925 /* Don't load .exit sections */
2926 if (strstarts(info->secstrings+shdr->sh_name, ".exit"))
2927 shdr->sh_flags &= ~(unsigned long)SHF_ALLOC;
2928#endif
2929 }
2930
2931 /* Track but don't keep modinfo and version sections. */
2932 if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
2933 info->index.vers = 0; /* Pretend no __versions section! */
2934 else
2935 info->index.vers = find_sec(info, "__versions");
2936 info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
2937
2938 info->index.info = find_sec(info, ".modinfo");
2939 if (!info->index.info)
2940 info->name = "(missing .modinfo section)";
2941 else
2942 info->name = get_modinfo(info, "name");
2943 info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
2944
2945 return 0;
2946}
2947
2948/*
2949 * Set up our basic convenience variables (pointers to section headers,
2950 * search for module section index etc), and do some basic section
2951 * verification.
2952 *
2953 * Return the temporary module pointer (we'll replace it with the final
2954 * one when we move the module sections around).
2955 */
2956static struct module *setup_load_info(struct load_info *info, int flags)
2957{
2958 unsigned int i;
2959 int err;
2960 struct module *mod;
2961
2962 /* Set up the convenience variables */
2963 info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
2964 info->secstrings = (void *)info->hdr
2965 + info->sechdrs[info->hdr->e_shstrndx].sh_offset;
2966
2967 err = rewrite_section_headers(info, flags);
2968 if (err)
2969 return ERR_PTR(err);
2970
2971 /* Find internal symbols and strings. */
2972 for (i = 1; i < info->hdr->e_shnum; i++) {
2973 if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
2974 info->index.sym = i;
2975 info->index.str = info->sechdrs[i].sh_link;
2976 info->strtab = (char *)info->hdr
2977 + info->sechdrs[info->index.str].sh_offset;
2978 break;
2979 }
2980 }
2981
2982 info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
2983 if (!info->index.mod) {
2984 pr_warn("%s: No module found in object\n",
2985 info->name ?: "(missing .modinfo name field)");
2986 return ERR_PTR(-ENOEXEC);
2987 }
2988 /* This is temporary: point mod into copy of data. */
2989 mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2990
2991 /*
2992 * If we didn't load the .modinfo 'name' field, fall back to
2993 * on-disk struct mod 'name' field.
2994 */
2995 if (!info->name)
2996 info->name = mod->name;
2997
2998 if (info->index.sym == 0) {
2999 pr_warn("%s: module has no symbols (stripped?)\n", info->name);
3000 return ERR_PTR(-ENOEXEC);
3001 }
3002
3003 info->index.pcpu = find_pcpusec(info);
3004
3005 /* Check module struct version now, before we try to use module. */
3006 if (!check_modstruct_version(info, mod))
3007 return ERR_PTR(-ENOEXEC);
3008
3009 return mod;
3010}
3011
3012static int check_modinfo(struct module *mod, struct load_info *info, int flags)
3013{
3014 const char *modmagic = get_modinfo(info, "vermagic");
3015 int err;
3016
3017 if (flags & MODULE_INIT_IGNORE_VERMAGIC)
3018 modmagic = NULL;
3019
3020 /* This is allowed: modprobe --force will invalidate it. */
3021 if (!modmagic) {
3022 err = try_to_force_load(mod, "bad vermagic");
3023 if (err)
3024 return err;
3025 } else if (!same_magic(modmagic, vermagic, info->index.vers)) {
3026 pr_err("%s: version magic '%s' should be '%s'\n",
3027 info->name, modmagic, vermagic);
3028 return -ENOEXEC;
3029 }
3030
3031 if (!get_modinfo(info, "intree")) {
3032 if (!test_taint(TAINT_OOT_MODULE))
3033 pr_warn("%s: loading out-of-tree module taints kernel.\n",
3034 mod->name);
3035 add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
3036 }
3037
3038 check_modinfo_retpoline(mod, info);
3039
3040 if (get_modinfo(info, "staging")) {
3041 add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
3042 pr_warn("%s: module is from the staging directory, the quality "
3043 "is unknown, you have been warned.\n", mod->name);
3044 }
3045
3046 err = check_modinfo_livepatch(mod, info);
3047 if (err)
3048 return err;
3049
3050 /* Set up license info based on the info section */
3051 set_license(mod, get_modinfo(info, "license"));
3052
3053 return 0;
3054}
3055
3056static int find_module_sections(struct module *mod, struct load_info *info)
3057{
3058 mod->kp = section_objs(info, "__param",
3059 sizeof(*mod->kp), &mod->num_kp);
3060 mod->syms = section_objs(info, "__ksymtab",
3061 sizeof(*mod->syms), &mod->num_syms);
3062 mod->crcs = section_addr(info, "__kcrctab");
3063 mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
3064 sizeof(*mod->gpl_syms),
3065 &mod->num_gpl_syms);
3066 mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
3067 mod->gpl_future_syms = section_objs(info,
3068 "__ksymtab_gpl_future",
3069 sizeof(*mod->gpl_future_syms),
3070 &mod->num_gpl_future_syms);
3071 mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future");
3072
3073#ifdef CONFIG_UNUSED_SYMBOLS
3074 mod->unused_syms = section_objs(info, "__ksymtab_unused",
3075 sizeof(*mod->unused_syms),
3076 &mod->num_unused_syms);
3077 mod->unused_crcs = section_addr(info, "__kcrctab_unused");
3078 mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl",
3079 sizeof(*mod->unused_gpl_syms),
3080 &mod->num_unused_gpl_syms);
3081 mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl");
3082#endif
3083#ifdef CONFIG_CONSTRUCTORS
3084 mod->ctors = section_objs(info, ".ctors",
3085 sizeof(*mod->ctors), &mod->num_ctors);
3086 if (!mod->ctors)
3087 mod->ctors = section_objs(info, ".init_array",
3088 sizeof(*mod->ctors), &mod->num_ctors);
3089 else if (find_sec(info, ".init_array")) {
3090 /*
3091 * This shouldn't happen with same compiler and binutils
3092 * building all parts of the module.
3093 */
3094 pr_warn("%s: has both .ctors and .init_array.\n",
3095 mod->name);
3096 return -EINVAL;
3097 }
3098#endif
3099
3100#ifdef CONFIG_TRACEPOINTS
3101 mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
3102 sizeof(*mod->tracepoints_ptrs),
3103 &mod->num_tracepoints);
3104#endif
3105#ifdef HAVE_JUMP_LABEL
3106 mod->jump_entries = section_objs(info, "__jump_table",
3107 sizeof(*mod->jump_entries),
3108 &mod->num_jump_entries);
3109#endif
3110#ifdef CONFIG_EVENT_TRACING
3111 mod->trace_events = section_objs(info, "_ftrace_events",
3112 sizeof(*mod->trace_events),
3113 &mod->num_trace_events);
3114 mod->trace_evals = section_objs(info, "_ftrace_eval_map",
3115 sizeof(*mod->trace_evals),
3116 &mod->num_trace_evals);
3117#endif
3118#ifdef CONFIG_TRACING
3119 mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
3120 sizeof(*mod->trace_bprintk_fmt_start),
3121 &mod->num_trace_bprintk_fmt);
3122#endif
3123#ifdef CONFIG_FTRACE_MCOUNT_RECORD
3124 /* sechdrs[0].sh_size is always zero */
3125 mod->ftrace_callsites = section_objs(info, "__mcount_loc",
3126 sizeof(*mod->ftrace_callsites),
3127 &mod->num_ftrace_callsites);
3128#endif
3129#ifdef CONFIG_FUNCTION_ERROR_INJECTION
3130 mod->ei_funcs = section_objs(info, "_error_injection_whitelist",
3131 sizeof(*mod->ei_funcs),
3132 &mod->num_ei_funcs);
3133#endif
3134 mod->extable = section_objs(info, "__ex_table",
3135 sizeof(*mod->extable), &mod->num_exentries);
3136
3137 if (section_addr(info, "__obsparm"))
3138 pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
3139
3140 info->debug = section_objs(info, "__verbose",
3141 sizeof(*info->debug), &info->num_debug);
3142
3143 return 0;
3144}
3145
3146static int move_module(struct module *mod, struct load_info *info)
3147{
3148 int i;
3149 void *ptr;
3150
3151 /* Do the allocs. */
3152 ptr = module_alloc(mod->core_layout.size);
3153 /*
3154 * The pointer to this block is stored in the module structure
3155 * which is inside the block. Just mark it as not being a
3156 * leak.
3157 */
3158 kmemleak_not_leak(ptr);
3159 if (!ptr)
3160 return -ENOMEM;
3161
3162 memset(ptr, 0, mod->core_layout.size);
3163 mod->core_layout.base = ptr;
3164
3165 if (mod->init_layout.size) {
3166 ptr = module_alloc(mod->init_layout.size);
3167 /*
3168 * The pointer to this block is stored in the module structure
3169 * which is inside the block. This block doesn't need to be
3170 * scanned as it contains data and code that will be freed
3171 * after the module is initialized.
3172 */
3173 kmemleak_ignore(ptr);
3174 if (!ptr) {
3175 module_memfree(mod->core_layout.base);
3176 return -ENOMEM;
3177 }
3178 memset(ptr, 0, mod->init_layout.size);
3179 mod->init_layout.base = ptr;
3180 } else
3181 mod->init_layout.base = NULL;
3182
3183 /* Transfer each section which specifies SHF_ALLOC */
3184 pr_debug("final section addresses:\n");
3185 for (i = 0; i < info->hdr->e_shnum; i++) {
3186 void *dest;
3187 Elf_Shdr *shdr = &info->sechdrs[i];
3188
3189 if (!(shdr->sh_flags & SHF_ALLOC))
3190 continue;
3191
3192 if (shdr->sh_entsize & INIT_OFFSET_MASK)
3193 dest = mod->init_layout.base
3194 + (shdr->sh_entsize & ~INIT_OFFSET_MASK);
3195 else
3196 dest = mod->core_layout.base + shdr->sh_entsize;
3197
3198 if (shdr->sh_type != SHT_NOBITS)
3199 memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
3200 /* Update sh_addr to point to copy in image. */
3201 shdr->sh_addr = (unsigned long)dest;
3202 pr_debug("\t0x%lx %s\n",
3203 (long)shdr->sh_addr, info->secstrings + shdr->sh_name);
3204 }
3205
3206 return 0;
3207}
3208
3209static int check_module_license_and_versions(struct module *mod)
3210{
3211 int prev_taint = test_taint(TAINT_PROPRIETARY_MODULE);
3212
3213 /*
3214 * ndiswrapper is under GPL by itself, but loads proprietary modules.
3215 * Don't use add_taint_module(), as it would prevent ndiswrapper from
3216 * using GPL-only symbols it needs.
3217 */
3218 if (strcmp(mod->name, "ndiswrapper") == 0)
3219 add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
3220
3221 /* driverloader was caught wrongly pretending to be under GPL */
3222 if (strcmp(mod->name, "driverloader") == 0)
3223 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3224 LOCKDEP_NOW_UNRELIABLE);
3225
3226 /* lve claims to be GPL but upstream won't provide source */
3227 if (strcmp(mod->name, "lve") == 0)
3228 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3229 LOCKDEP_NOW_UNRELIABLE);
3230
3231 if (!prev_taint && test_taint(TAINT_PROPRIETARY_MODULE))
3232 pr_warn("%s: module license taints kernel.\n", mod->name);
3233
3234#ifdef CONFIG_MODVERSIONS
3235 if ((mod->num_syms && !mod->crcs)
3236 || (mod->num_gpl_syms && !mod->gpl_crcs)
3237 || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
3238#ifdef CONFIG_UNUSED_SYMBOLS
3239 || (mod->num_unused_syms && !mod->unused_crcs)
3240 || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
3241#endif
3242 ) {
3243 return try_to_force_load(mod,
3244 "no versions for exported symbols");
3245 }
3246#endif
3247 return 0;
3248}
3249
3250static void flush_module_icache(const struct module *mod)
3251{
3252 mm_segment_t old_fs;
3253
3254 /* flush the icache in correct context */
3255 old_fs = get_fs();
3256 set_fs(KERNEL_DS);
3257
3258 /*
3259 * Flush the instruction cache, since we've played with text.
3260 * Do it before processing of module parameters, so the module
3261 * can provide parameter accessor functions of its own.
3262 */
3263 if (mod->init_layout.base)
3264 flush_icache_range((unsigned long)mod->init_layout.base,
3265 (unsigned long)mod->init_layout.base
3266 + mod->init_layout.size);
3267 flush_icache_range((unsigned long)mod->core_layout.base,
3268 (unsigned long)mod->core_layout.base + mod->core_layout.size);
3269
3270 set_fs(old_fs);
3271}
3272
3273int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
3274 Elf_Shdr *sechdrs,
3275 char *secstrings,
3276 struct module *mod)
3277{
3278 return 0;
3279}
3280
3281/* module_blacklist is a comma-separated list of module names */
3282static char *module_blacklist;
3283static bool blacklisted(const char *module_name)
3284{
3285 const char *p;
3286 size_t len;
3287
3288 if (!module_blacklist)
3289 return false;
3290
3291 for (p = module_blacklist; *p; p += len) {
3292 len = strcspn(p, ",");
3293 if (strlen(module_name) == len && !memcmp(module_name, p, len))
3294 return true;
3295 if (p[len] == ',')
3296 len++;
3297 }
3298 return false;
3299}
3300core_param(module_blacklist, module_blacklist, charp, 0400);
3301
3302static struct module *layout_and_allocate(struct load_info *info, int flags)
3303{
3304 /* Module within temporary copy. */
3305 struct module *mod;
3306 unsigned int ndx;
3307 int err;
3308
3309 mod = setup_load_info(info, flags);
3310 if (IS_ERR(mod))
3311 return mod;
3312
3313 if (blacklisted(info->name))
3314 return ERR_PTR(-EPERM);
3315
3316 err = check_modinfo(mod, info, flags);
3317 if (err)
3318 return ERR_PTR(err);
3319
3320 /* Allow arches to frob section contents and sizes. */
3321 err = module_frob_arch_sections(info->hdr, info->sechdrs,
3322 info->secstrings, mod);
3323 if (err < 0)
3324 return ERR_PTR(err);
3325
3326 /* We will do a special allocation for per-cpu sections later. */
3327 info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC;
3328
3329 /*
3330 * Mark ro_after_init section with SHF_RO_AFTER_INIT so that
3331 * layout_sections() can put it in the right place.
3332 * Note: ro_after_init sections also have SHF_{WRITE,ALLOC} set.
3333 */
3334 ndx = find_sec(info, ".data..ro_after_init");
3335 if (ndx)
3336 info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT;
3337
3338 /* Determine total sizes, and put offsets in sh_entsize. For now
3339 this is done generically; there doesn't appear to be any
3340 special cases for the architectures. */
3341 layout_sections(mod, info);
3342 layout_symtab(mod, info);
3343
3344 /* Allocate and move to the final place */
3345 err = move_module(mod, info);
3346 if (err)
3347 return ERR_PTR(err);
3348
3349 /* Module has been copied to its final place now: return it. */
3350 mod = (void *)info->sechdrs[info->index.mod].sh_addr;
3351 kmemleak_load_module(mod, info);
3352 return mod;
3353}
3354
3355/* mod is no longer valid after this! */
3356static void module_deallocate(struct module *mod, struct load_info *info)
3357{
3358 percpu_modfree(mod);
3359 module_arch_freeing_init(mod);
3360 module_memfree(mod->init_layout.base);
3361 module_memfree(mod->core_layout.base);
3362}
3363
3364int __weak module_finalize(const Elf_Ehdr *hdr,
3365 const Elf_Shdr *sechdrs,
3366 struct module *me)
3367{
3368 return 0;
3369}
3370
3371static int post_relocation(struct module *mod, const struct load_info *info)
3372{
3373 /* Sort exception table now relocations are done. */
3374 sort_extable(mod->extable, mod->extable + mod->num_exentries);
3375
3376 /* Copy relocated percpu area over. */
3377 percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
3378 info->sechdrs[info->index.pcpu].sh_size);
3379
3380 /* Setup kallsyms-specific fields. */
3381 add_kallsyms(mod, info);
3382
3383 /* Arch-specific module finalizing. */
3384 return module_finalize(info->hdr, info->sechdrs, mod);
3385}
3386
3387/* Is this module of this name done loading? No locks held. */
3388static bool finished_loading(const char *name)
3389{
3390 struct module *mod;
3391 bool ret;
3392
3393 /*
3394 * The module_mutex should not be a heavily contended lock;
3395 * if we get the occasional sleep here, we'll go an extra iteration
3396 * in the wait_event_interruptible(), which is harmless.
3397 */
3398 sched_annotate_sleep();
3399 mutex_lock(&module_mutex);
3400 mod = find_module_all(name, strlen(name), true);
3401 ret = !mod || mod->state == MODULE_STATE_LIVE
3402 || mod->state == MODULE_STATE_GOING;
3403 mutex_unlock(&module_mutex);
3404
3405 return ret;
3406}
3407
3408/* Call module constructors. */
3409static void do_mod_ctors(struct module *mod)
3410{
3411#ifdef CONFIG_CONSTRUCTORS
3412 unsigned long i;
3413
3414 for (i = 0; i < mod->num_ctors; i++)
3415 mod->ctors[i]();
3416#endif
3417}
3418
3419/* For freeing module_init on success, in case kallsyms traversing */
3420struct mod_initfree {
3421 struct rcu_head rcu;
3422 void *module_init;
3423};
3424
3425static void do_free_init(struct rcu_head *head)
3426{
3427 struct mod_initfree *m = container_of(head, struct mod_initfree, rcu);
3428 module_memfree(m->module_init);
3429 kfree(m);
3430}
3431
3432/*
3433 * This is where the real work happens.
3434 *
3435 * Keep it uninlined to provide a reliable breakpoint target, e.g. for the gdb
3436 * helper command 'lx-symbols'.
3437 */
3438static noinline int do_init_module(struct module *mod)
3439{
3440 int ret = 0;
3441 struct mod_initfree *freeinit;
3442
3443 freeinit = kmalloc(sizeof(*freeinit), GFP_KERNEL);
3444 if (!freeinit) {
3445 ret = -ENOMEM;
3446 goto fail;
3447 }
3448 freeinit->module_init = mod->init_layout.base;
3449
3450 /*
3451 * We want to find out whether @mod uses async during init. Clear
3452 * PF_USED_ASYNC. async_schedule*() will set it.
3453 */
3454 current->flags &= ~PF_USED_ASYNC;
3455
3456 do_mod_ctors(mod);
3457 /* Start the module */
3458 if (mod->init != NULL)
3459 ret = do_one_initcall(mod->init);
3460 if (ret < 0) {
3461 goto fail_free_freeinit;
3462 }
3463 if (ret > 0) {
3464 pr_warn("%s: '%s'->init suspiciously returned %d, it should "
3465 "follow 0/-E convention\n"
3466 "%s: loading module anyway...\n",
3467 __func__, mod->name, ret, __func__);
3468 dump_stack();
3469 }
3470
3471 /* Now it's a first class citizen! */
3472 mod->state = MODULE_STATE_LIVE;
3473 blocking_notifier_call_chain(&module_notify_list,
3474 MODULE_STATE_LIVE, mod);
3475
3476 /*
3477 * We need to finish all async code before the module init sequence
3478 * is done. This has potential to deadlock. For example, a newly
3479 * detected block device can trigger request_module() of the
3480 * default iosched from async probing task. Once userland helper
3481 * reaches here, async_synchronize_full() will wait on the async
3482 * task waiting on request_module() and deadlock.
3483 *
3484 * This deadlock is avoided by perfomring async_synchronize_full()
3485 * iff module init queued any async jobs. This isn't a full
3486 * solution as it will deadlock the same if module loading from
3487 * async jobs nests more than once; however, due to the various
3488 * constraints, this hack seems to be the best option for now.
3489 * Please refer to the following thread for details.
3490 *
3491 * http://thread.gmane.org/gmane.linux.kernel/1420814
3492 */
3493 if (!mod->async_probe_requested && (current->flags & PF_USED_ASYNC))
3494 async_synchronize_full();
3495
3496 ftrace_free_mem(mod, mod->init_layout.base, mod->init_layout.base +
3497 mod->init_layout.size);
3498 mutex_lock(&module_mutex);
3499 /* Drop initial reference. */
3500 module_put(mod);
3501 trim_init_extable(mod);
3502#ifdef CONFIG_KALLSYMS
3503 /* Switch to core kallsyms now init is done: kallsyms may be walking! */
3504 rcu_assign_pointer(mod->kallsyms, &mod->core_kallsyms);
3505#endif
3506 module_enable_ro(mod, true);
3507 mod_tree_remove_init(mod);
3508 disable_ro_nx(&mod->init_layout);
3509 module_arch_freeing_init(mod);
3510 mod->init_layout.base = NULL;
3511 mod->init_layout.size = 0;
3512 mod->init_layout.ro_size = 0;
3513 mod->init_layout.ro_after_init_size = 0;
3514 mod->init_layout.text_size = 0;
3515 /*
3516 * We want to free module_init, but be aware that kallsyms may be
3517 * walking this with preempt disabled. In all the failure paths, we
3518 * call synchronize_sched(), but we don't want to slow down the success
3519 * path, so use actual RCU here.
3520 * Note that module_alloc() on most architectures creates W+X page
3521 * mappings which won't be cleaned up until do_free_init() runs. Any
3522 * code such as mark_rodata_ro() which depends on those mappings to
3523 * be cleaned up needs to sync with the queued work - ie
3524 * rcu_barrier_sched()
3525 */
3526 call_rcu_sched(&freeinit->rcu, do_free_init);
3527 mutex_unlock(&module_mutex);
3528 wake_up_all(&module_wq);
3529
3530 return 0;
3531
3532fail_free_freeinit:
3533 kfree(freeinit);
3534fail:
3535 /* Try to protect us from buggy refcounters. */
3536 mod->state = MODULE_STATE_GOING;
3537 synchronize_sched();
3538 module_put(mod);
3539 blocking_notifier_call_chain(&module_notify_list,
3540 MODULE_STATE_GOING, mod);
3541 klp_module_going(mod);
3542 ftrace_release_mod(mod);
3543 free_module(mod);
3544 wake_up_all(&module_wq);
3545 return ret;
3546}
3547
3548static int may_init_module(void)
3549{
3550 if (!capable(CAP_SYS_MODULE) || modules_disabled)
3551 return -EPERM;
3552
3553 return 0;
3554}
3555
3556/*
3557 * We try to place it in the list now to make sure it's unique before
3558 * we dedicate too many resources. In particular, temporary percpu
3559 * memory exhaustion.
3560 */
3561static int add_unformed_module(struct module *mod)
3562{
3563 int err;
3564 struct module *old;
3565
3566 mod->state = MODULE_STATE_UNFORMED;
3567
3568again:
3569 mutex_lock(&module_mutex);
3570 old = find_module_all(mod->name, strlen(mod->name), true);
3571 if (old != NULL) {
3572 if (old->state == MODULE_STATE_COMING
3573 || old->state == MODULE_STATE_UNFORMED) {
3574 /* Wait in case it fails to load. */
3575 mutex_unlock(&module_mutex);
3576 err = wait_event_interruptible(module_wq,
3577 finished_loading(mod->name));
3578 if (err)
3579 goto out_unlocked;
3580 goto again;
3581 }
3582 err = -EEXIST;
3583 goto out;
3584 }
3585 mod_update_bounds(mod);
3586 list_add_rcu(&mod->list, &modules);
3587 mod_tree_insert(mod);
3588 err = 0;
3589
3590out:
3591 mutex_unlock(&module_mutex);
3592out_unlocked:
3593 return err;
3594}
3595
3596static int complete_formation(struct module *mod, struct load_info *info)
3597{
3598 int err;
3599
3600 mutex_lock(&module_mutex);
3601
3602 /* Find duplicate symbols (must be called under lock). */
3603 err = verify_export_symbols(mod);
3604 if (err < 0)
3605 goto out;
3606
3607 /* This relies on module_mutex for list integrity. */
3608 module_bug_finalize(info->hdr, info->sechdrs, mod);
3609
3610 module_enable_ro(mod, false);
3611 module_enable_nx(mod);
3612
3613 /* Mark state as coming so strong_try_module_get() ignores us,
3614 * but kallsyms etc. can see us. */
3615 mod->state = MODULE_STATE_COMING;
3616 mutex_unlock(&module_mutex);
3617
3618 return 0;
3619
3620out:
3621 mutex_unlock(&module_mutex);
3622 return err;
3623}
3624
3625static int prepare_coming_module(struct module *mod)
3626{
3627 int err;
3628
3629 ftrace_module_enable(mod);
3630 err = klp_module_coming(mod);
3631 if (err)
3632 return err;
3633
3634 blocking_notifier_call_chain(&module_notify_list,
3635 MODULE_STATE_COMING, mod);
3636 return 0;
3637}
3638
3639static int unknown_module_param_cb(char *param, char *val, const char *modname,
3640 void *arg)
3641{
3642 struct module *mod = arg;
3643 int ret;
3644
3645 if (strcmp(param, "async_probe") == 0) {
3646 mod->async_probe_requested = true;
3647 return 0;
3648 }
3649
3650 /* Check for magic 'dyndbg' arg */
3651 ret = ddebug_dyndbg_module_param_cb(param, val, modname);
3652 if (ret != 0)
3653 pr_warn("%s: unknown parameter '%s' ignored\n", modname, param);
3654 return 0;
3655}
3656
3657/* Allocate and load the module: note that size of section 0 is always
3658 zero, and we rely on this for optional sections. */
3659static int load_module(struct load_info *info, const char __user *uargs,
3660 int flags)
3661{
3662 struct module *mod;
3663 long err;
3664 char *after_dashes;
3665
3666 err = module_sig_check(info, flags);
3667 if (err)
3668 goto free_copy;
3669
3670 err = elf_header_check(info);
3671 if (err)
3672 goto free_copy;
3673
3674 /* Figure out module layout, and allocate all the memory. */
3675 mod = layout_and_allocate(info, flags);
3676 if (IS_ERR(mod)) {
3677 err = PTR_ERR(mod);
3678 goto free_copy;
3679 }
3680
3681 audit_log_kern_module(mod->name);
3682
3683 /* Reserve our place in the list. */
3684 err = add_unformed_module(mod);
3685 if (err)
3686 goto free_module;
3687
3688#ifdef CONFIG_MODULE_SIG
3689 mod->sig_ok = info->sig_ok;
3690 if (!mod->sig_ok) {
3691 pr_notice_once("%s: module verification failed: signature "
3692 "and/or required key missing - tainting "
3693 "kernel\n", mod->name);
3694 add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK);
3695 }
3696#endif
3697
3698 /* To avoid stressing percpu allocator, do this once we're unique. */
3699 err = percpu_modalloc(mod, info);
3700 if (err)
3701 goto unlink_mod;
3702
3703 /* Now module is in final location, initialize linked lists, etc. */
3704 err = module_unload_init(mod);
3705 if (err)
3706 goto unlink_mod;
3707
3708 init_param_lock(mod);
3709
3710 /* Now we've got everything in the final locations, we can
3711 * find optional sections. */
3712 err = find_module_sections(mod, info);
3713 if (err)
3714 goto free_unload;
3715
3716 err = check_module_license_and_versions(mod);
3717 if (err)
3718 goto free_unload;
3719
3720 /* Set up MODINFO_ATTR fields */
3721 setup_modinfo(mod, info);
3722
3723 /* Fix up syms, so that st_value is a pointer to location. */
3724 err = simplify_symbols(mod, info);
3725 if (err < 0)
3726 goto free_modinfo;
3727
3728 err = apply_relocations(mod, info);
3729 if (err < 0)
3730 goto free_modinfo;
3731
3732 err = post_relocation(mod, info);
3733 if (err < 0)
3734 goto free_modinfo;
3735
3736 flush_module_icache(mod);
3737
3738 /* Now copy in args */
3739 mod->args = strndup_user(uargs, ~0UL >> 1);
3740 if (IS_ERR(mod->args)) {
3741 err = PTR_ERR(mod->args);
3742 goto free_arch_cleanup;
3743 }
3744
3745 dynamic_debug_setup(mod, info->debug, info->num_debug);
3746
3747 /* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
3748 ftrace_module_init(mod);
3749
3750 /* Finally it's fully formed, ready to start executing. */
3751 err = complete_formation(mod, info);
3752 if (err)
3753 goto ddebug_cleanup;
3754
3755 err = prepare_coming_module(mod);
3756 if (err)
3757 goto bug_cleanup;
3758
3759 /* Module is ready to execute: parsing args may do that. */
3760 after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
3761 -32768, 32767, mod,
3762 unknown_module_param_cb);
3763 if (IS_ERR(after_dashes)) {
3764 err = PTR_ERR(after_dashes);
3765 goto coming_cleanup;
3766 } else if (after_dashes) {
3767 pr_warn("%s: parameters '%s' after `--' ignored\n",
3768 mod->name, after_dashes);
3769 }
3770
3771 /* Link in to sysfs. */
3772 err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
3773 if (err < 0)
3774 goto coming_cleanup;
3775
3776 if (is_livepatch_module(mod)) {
3777 err = copy_module_elf(mod, info);
3778 if (err < 0)
3779 goto sysfs_cleanup;
3780 }
3781
3782 /* Get rid of temporary copy. */
3783 free_copy(info);
3784
3785 /* Done! */
3786 trace_module_load(mod);
3787
3788 return do_init_module(mod);
3789
3790 sysfs_cleanup:
3791 mod_sysfs_teardown(mod);
3792 coming_cleanup:
3793 mod->state = MODULE_STATE_GOING;
3794 destroy_params(mod->kp, mod->num_kp);
3795 blocking_notifier_call_chain(&module_notify_list,
3796 MODULE_STATE_GOING, mod);
3797 klp_module_going(mod);
3798 bug_cleanup:
3799 /* module_bug_cleanup needs module_mutex protection */
3800 mutex_lock(&module_mutex);
3801 module_bug_cleanup(mod);
3802 mutex_unlock(&module_mutex);
3803
3804 /* we can't deallocate the module until we clear memory protection */
3805 module_disable_ro(mod);
3806 module_disable_nx(mod);
3807
3808 ddebug_cleanup:
3809 ftrace_release_mod(mod);
3810 dynamic_debug_remove(mod, info->debug);
3811 synchronize_sched();
3812 kfree(mod->args);
3813 free_arch_cleanup:
3814 module_arch_cleanup(mod);
3815 free_modinfo:
3816 free_modinfo(mod);
3817 free_unload:
3818 module_unload_free(mod);
3819 unlink_mod:
3820 mutex_lock(&module_mutex);
3821 /* Unlink carefully: kallsyms could be walking list. */
3822 list_del_rcu(&mod->list);
3823 mod_tree_remove(mod);
3824 wake_up_all(&module_wq);
3825 /* Wait for RCU-sched synchronizing before releasing mod->list. */
3826 synchronize_sched();
3827 mutex_unlock(&module_mutex);
3828 free_module:
3829 /* Free lock-classes; relies on the preceding sync_rcu() */
3830 lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
3831
3832 module_deallocate(mod, info);
3833 free_copy:
3834 free_copy(info);
3835 return err;
3836}
3837
3838SYSCALL_DEFINE3(init_module, void __user *, umod,
3839 unsigned long, len, const char __user *, uargs)
3840{
3841 int err;
3842 struct load_info info = { };
3843
3844 err = may_init_module();
3845 if (err)
3846 return err;
3847
3848 pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
3849 umod, len, uargs);
3850
3851 err = copy_module_from_user(umod, len, &info);
3852 if (err)
3853 return err;
3854
3855 return load_module(&info, uargs, 0);
3856}
3857
3858SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
3859{
3860 struct load_info info = { };
3861 loff_t size;
3862 void *hdr;
3863 int err;
3864
3865 err = may_init_module();
3866 if (err)
3867 return err;
3868
3869 pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags);
3870
3871 if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS
3872 |MODULE_INIT_IGNORE_VERMAGIC))
3873 return -EINVAL;
3874
3875 err = kernel_read_file_from_fd(fd, &hdr, &size, INT_MAX,
3876 READING_MODULE);
3877 if (err)
3878 return err;
3879 info.hdr = hdr;
3880 info.len = size;
3881
3882 return load_module(&info, uargs, flags);
3883}
3884
3885static inline int within(unsigned long addr, void *start, unsigned long size)
3886{
3887 return ((void *)addr >= start && (void *)addr < start + size);
3888}
3889
3890#ifdef CONFIG_KALLSYMS
3891/*
3892 * This ignores the intensely annoying "mapping symbols" found
3893 * in ARM ELF files: $a, $t and $d.
3894 */
3895static inline int is_arm_mapping_symbol(const char *str)
3896{
3897 if (str[0] == '.' && str[1] == 'L')
3898 return true;
3899 return str[0] == '$' && strchr("axtd", str[1])
3900 && (str[2] == '\0' || str[2] == '.');
3901}
3902
3903static const char *symname(struct mod_kallsyms *kallsyms, unsigned int symnum)
3904{
3905 return kallsyms->strtab + kallsyms->symtab[symnum].st_name;
3906}
3907
3908static const char *get_ksymbol(struct module *mod,
3909 unsigned long addr,
3910 unsigned long *size,
3911 unsigned long *offset)
3912{
3913 unsigned int i, best = 0;
3914 unsigned long nextval;
3915 struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
3916
3917 /* At worse, next value is at end of module */
3918 if (within_module_init(addr, mod))
3919 nextval = (unsigned long)mod->init_layout.base+mod->init_layout.text_size;
3920 else
3921 nextval = (unsigned long)mod->core_layout.base+mod->core_layout.text_size;
3922
3923 /* Scan for closest preceding symbol, and next symbol. (ELF
3924 starts real symbols at 1). */
3925 for (i = 1; i < kallsyms->num_symtab; i++) {
3926 if (kallsyms->symtab[i].st_shndx == SHN_UNDEF)
3927 continue;
3928
3929 /* We ignore unnamed symbols: they're uninformative
3930 * and inserted at a whim. */
3931 if (*symname(kallsyms, i) == '\0'
3932 || is_arm_mapping_symbol(symname(kallsyms, i)))
3933 continue;
3934
3935 if (kallsyms->symtab[i].st_value <= addr
3936 && kallsyms->symtab[i].st_value > kallsyms->symtab[best].st_value)
3937 best = i;
3938 if (kallsyms->symtab[i].st_value > addr
3939 && kallsyms->symtab[i].st_value < nextval)
3940 nextval = kallsyms->symtab[i].st_value;
3941 }
3942
3943 if (!best)
3944 return NULL;
3945
3946 if (size)
3947 *size = nextval - kallsyms->symtab[best].st_value;
3948 if (offset)
3949 *offset = addr - kallsyms->symtab[best].st_value;
3950 return symname(kallsyms, best);
3951}
3952
3953void * __weak dereference_module_function_descriptor(struct module *mod,
3954 void *ptr)
3955{
3956 return ptr;
3957}
3958
3959/* For kallsyms to ask for address resolution. NULL means not found. Careful
3960 * not to lock to avoid deadlock on oopses, simply disable preemption. */
3961const char *module_address_lookup(unsigned long addr,
3962 unsigned long *size,
3963 unsigned long *offset,
3964 char **modname,
3965 char *namebuf)
3966{
3967 const char *ret = NULL;
3968 struct module *mod;
3969
3970 preempt_disable();
3971 mod = __module_address(addr);
3972 if (mod) {
3973 if (modname)
3974 *modname = mod->name;
3975 ret = get_ksymbol(mod, addr, size, offset);
3976 }
3977 /* Make a copy in here where it's safe */
3978 if (ret) {
3979 strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
3980 ret = namebuf;
3981 }
3982 preempt_enable();
3983
3984 return ret;
3985}
3986
3987int lookup_module_symbol_name(unsigned long addr, char *symname)
3988{
3989 struct module *mod;
3990
3991 preempt_disable();
3992 list_for_each_entry_rcu(mod, &modules, list) {
3993 if (mod->state == MODULE_STATE_UNFORMED)
3994 continue;
3995 if (within_module(addr, mod)) {
3996 const char *sym;
3997
3998 sym = get_ksymbol(mod, addr, NULL, NULL);
3999 if (!sym)
4000 goto out;
4001 strlcpy(symname, sym, KSYM_NAME_LEN);
4002 preempt_enable();
4003 return 0;
4004 }
4005 }
4006out:
4007 preempt_enable();
4008 return -ERANGE;
4009}
4010
4011int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
4012 unsigned long *offset, char *modname, char *name)
4013{
4014 struct module *mod;
4015
4016 preempt_disable();
4017 list_for_each_entry_rcu(mod, &modules, list) {
4018 if (mod->state == MODULE_STATE_UNFORMED)
4019 continue;
4020 if (within_module(addr, mod)) {
4021 const char *sym;
4022
4023 sym = get_ksymbol(mod, addr, size, offset);
4024 if (!sym)
4025 goto out;
4026 if (modname)
4027 strlcpy(modname, mod->name, MODULE_NAME_LEN);
4028 if (name)
4029 strlcpy(name, sym, KSYM_NAME_LEN);
4030 preempt_enable();
4031 return 0;
4032 }
4033 }
4034out:
4035 preempt_enable();
4036 return -ERANGE;
4037}
4038
4039int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
4040 char *name, char *module_name, int *exported)
4041{
4042 struct module *mod;
4043
4044 preempt_disable();
4045 list_for_each_entry_rcu(mod, &modules, list) {
4046 struct mod_kallsyms *kallsyms;
4047
4048 if (mod->state == MODULE_STATE_UNFORMED)
4049 continue;
4050 kallsyms = rcu_dereference_sched(mod->kallsyms);
4051 if (symnum < kallsyms->num_symtab) {
4052 *value = kallsyms->symtab[symnum].st_value;
4053 *type = kallsyms->symtab[symnum].st_info;
4054 strlcpy(name, symname(kallsyms, symnum), KSYM_NAME_LEN);
4055 strlcpy(module_name, mod->name, MODULE_NAME_LEN);
4056 *exported = is_exported(name, *value, mod);
4057 preempt_enable();
4058 return 0;
4059 }
4060 symnum -= kallsyms->num_symtab;
4061 }
4062 preempt_enable();
4063 return -ERANGE;
4064}
4065
4066static unsigned long mod_find_symname(struct module *mod, const char *name)
4067{
4068 unsigned int i;
4069 struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
4070
4071 for (i = 0; i < kallsyms->num_symtab; i++)
4072 if (strcmp(name, symname(kallsyms, i)) == 0 &&
4073 kallsyms->symtab[i].st_info != 'U')
4074 return kallsyms->symtab[i].st_value;
4075 return 0;
4076}
4077
4078/* Look for this name: can be of form module:name. */
4079unsigned long module_kallsyms_lookup_name(const char *name)
4080{
4081 struct module *mod;
4082 char *colon;
4083 unsigned long ret = 0;
4084
4085 /* Don't lock: we're in enough trouble already. */
4086 preempt_disable();
4087 if ((colon = strnchr(name, MODULE_NAME_LEN, ':')) != NULL) {
4088 if ((mod = find_module_all(name, colon - name, false)) != NULL)
4089 ret = mod_find_symname(mod, colon+1);
4090 } else {
4091 list_for_each_entry_rcu(mod, &modules, list) {
4092 if (mod->state == MODULE_STATE_UNFORMED)
4093 continue;
4094 if ((ret = mod_find_symname(mod, name)) != 0)
4095 break;
4096 }
4097 }
4098 preempt_enable();
4099 return ret;
4100}
4101
4102int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
4103 struct module *, unsigned long),
4104 void *data)
4105{
4106 struct module *mod;
4107 unsigned int i;
4108 int ret;
4109
4110 module_assert_mutex();
4111
4112 list_for_each_entry(mod, &modules, list) {
4113 /* We hold module_mutex: no need for rcu_dereference_sched */
4114 struct mod_kallsyms *kallsyms = mod->kallsyms;
4115
4116 if (mod->state == MODULE_STATE_UNFORMED)
4117 continue;
4118 for (i = 0; i < kallsyms->num_symtab; i++) {
4119 ret = fn(data, symname(kallsyms, i),
4120 mod, kallsyms->symtab[i].st_value);
4121 if (ret != 0)
4122 return ret;
4123 }
4124 }
4125 return 0;
4126}
4127#endif /* CONFIG_KALLSYMS */
4128
4129/* Maximum number of characters written by module_flags() */
4130#define MODULE_FLAGS_BUF_SIZE (TAINT_FLAGS_COUNT + 4)
4131
4132/* Keep in sync with MODULE_FLAGS_BUF_SIZE !!! */
4133static char *module_flags(struct module *mod, char *buf)
4134{
4135 int bx = 0;
4136
4137 BUG_ON(mod->state == MODULE_STATE_UNFORMED);
4138 if (mod->taints ||
4139 mod->state == MODULE_STATE_GOING ||
4140 mod->state == MODULE_STATE_COMING) {
4141 buf[bx++] = '(';
4142 bx += module_flags_taint(mod, buf + bx);
4143 /* Show a - for module-is-being-unloaded */
4144 if (mod->state == MODULE_STATE_GOING)
4145 buf[bx++] = '-';
4146 /* Show a + for module-is-being-loaded */
4147 if (mod->state == MODULE_STATE_COMING)
4148 buf[bx++] = '+';
4149 buf[bx++] = ')';
4150 }
4151 buf[bx] = '\0';
4152
4153 return buf;
4154}
4155
4156#ifdef CONFIG_PROC_FS
4157/* Called by the /proc file system to return a list of modules. */
4158static void *m_start(struct seq_file *m, loff_t *pos)
4159{
4160 mutex_lock(&module_mutex);
4161 return seq_list_start(&modules, *pos);
4162}
4163
4164static void *m_next(struct seq_file *m, void *p, loff_t *pos)
4165{
4166 return seq_list_next(p, &modules, pos);
4167}
4168
4169static void m_stop(struct seq_file *m, void *p)
4170{
4171 mutex_unlock(&module_mutex);
4172}
4173
4174static int m_show(struct seq_file *m, void *p)
4175{
4176 struct module *mod = list_entry(p, struct module, list);
4177 char buf[MODULE_FLAGS_BUF_SIZE];
4178 void *value;
4179
4180 /* We always ignore unformed modules. */
4181 if (mod->state == MODULE_STATE_UNFORMED)
4182 return 0;
4183
4184 seq_printf(m, "%s %u",
4185 mod->name, mod->init_layout.size + mod->core_layout.size);
4186 print_unload_info(m, mod);
4187
4188 /* Informative for users. */
4189 seq_printf(m, " %s",
4190 mod->state == MODULE_STATE_GOING ? "Unloading" :
4191 mod->state == MODULE_STATE_COMING ? "Loading" :
4192 "Live");
4193 /* Used by oprofile and other similar tools. */
4194 value = m->private ? NULL : mod->core_layout.base;
4195 seq_printf(m, " 0x%px", value);
4196
4197 /* Taints info */
4198 if (mod->taints)
4199 seq_printf(m, " %s", module_flags(mod, buf));
4200
4201 seq_puts(m, "\n");
4202 return 0;
4203}
4204
4205/* Format: modulename size refcount deps address
4206
4207 Where refcount is a number or -, and deps is a comma-separated list
4208 of depends or -.
4209*/
4210static const struct seq_operations modules_op = {
4211 .start = m_start,
4212 .next = m_next,
4213 .stop = m_stop,
4214 .show = m_show
4215};
4216
4217/*
4218 * This also sets the "private" pointer to non-NULL if the
4219 * kernel pointers should be hidden (so you can just test
4220 * "m->private" to see if you should keep the values private).
4221 *
4222 * We use the same logic as for /proc/kallsyms.
4223 */
4224static int modules_open(struct inode *inode, struct file *file)
4225{
4226 int err = seq_open(file, &modules_op);
4227
4228 if (!err) {
4229 struct seq_file *m = file->private_data;
4230 m->private = kallsyms_show_value() ? NULL : (void *)8ul;
4231 }
4232
4233 return err;
4234}
4235
4236static const struct file_operations proc_modules_operations = {
4237 .open = modules_open,
4238 .read = seq_read,
4239 .llseek = seq_lseek,
4240 .release = seq_release,
4241};
4242
4243static int __init proc_modules_init(void)
4244{
4245 proc_create("modules", 0, NULL, &proc_modules_operations);
4246 return 0;
4247}
4248module_init(proc_modules_init);
4249#endif
4250
4251/* Given an address, look for it in the module exception tables. */
4252const struct exception_table_entry *search_module_extables(unsigned long addr)
4253{
4254 const struct exception_table_entry *e = NULL;
4255 struct module *mod;
4256
4257 preempt_disable();
4258 mod = __module_address(addr);
4259 if (!mod)
4260 goto out;
4261
4262 if (!mod->num_exentries)
4263 goto out;
4264
4265 e = search_extable(mod->extable,
4266 mod->num_exentries,
4267 addr);
4268out:
4269 preempt_enable();
4270
4271 /*
4272 * Now, if we found one, we are running inside it now, hence
4273 * we cannot unload the module, hence no refcnt needed.
4274 */
4275 return e;
4276}
4277
4278/*
4279 * is_module_address - is this address inside a module?
4280 * @addr: the address to check.
4281 *
4282 * See is_module_text_address() if you simply want to see if the address
4283 * is code (not data).
4284 */
4285bool is_module_address(unsigned long addr)
4286{
4287 bool ret;
4288
4289 preempt_disable();
4290 ret = __module_address(addr) != NULL;
4291 preempt_enable();
4292
4293 return ret;
4294}
4295
4296/*
4297 * __module_address - get the module which contains an address.
4298 * @addr: the address.
4299 *
4300 * Must be called with preempt disabled or module mutex held so that
4301 * module doesn't get freed during this.
4302 */
4303struct module *__module_address(unsigned long addr)
4304{
4305 struct module *mod;
4306
4307 if (addr < module_addr_min || addr > module_addr_max)
4308 return NULL;
4309
4310 module_assert_mutex_or_preempt();
4311
4312 mod = mod_find(addr);
4313 if (mod) {
4314 BUG_ON(!within_module(addr, mod));
4315 if (mod->state == MODULE_STATE_UNFORMED)
4316 mod = NULL;
4317 }
4318 return mod;
4319}
4320EXPORT_SYMBOL_GPL(__module_address);
4321
4322/*
4323 * is_module_text_address - is this address inside module code?
4324 * @addr: the address to check.
4325 *
4326 * See is_module_address() if you simply want to see if the address is
4327 * anywhere in a module. See kernel_text_address() for testing if an
4328 * address corresponds to kernel or module code.
4329 */
4330bool is_module_text_address(unsigned long addr)
4331{
4332 bool ret;
4333
4334 preempt_disable();
4335 ret = __module_text_address(addr) != NULL;
4336 preempt_enable();
4337
4338 return ret;
4339}
4340
4341/*
4342 * __module_text_address - get the module whose code contains an address.
4343 * @addr: the address.
4344 *
4345 * Must be called with preempt disabled or module mutex held so that
4346 * module doesn't get freed during this.
4347 */
4348struct module *__module_text_address(unsigned long addr)
4349{
4350 struct module *mod = __module_address(addr);
4351 if (mod) {
4352 /* Make sure it's within the text section. */
4353 if (!within(addr, mod->init_layout.base, mod->init_layout.text_size)
4354 && !within(addr, mod->core_layout.base, mod->core_layout.text_size))
4355 mod = NULL;
4356 }
4357 return mod;
4358}
4359EXPORT_SYMBOL_GPL(__module_text_address);
4360
4361/* Don't grab lock, we're oopsing. */
4362void print_modules(void)
4363{
4364 struct module *mod;
4365 char buf[MODULE_FLAGS_BUF_SIZE];
4366
4367 printk(KERN_DEFAULT "Modules linked in:");
4368 /* Most callers should already have preempt disabled, but make sure */
4369 preempt_disable();
4370 list_for_each_entry_rcu(mod, &modules, list) {
4371 if (mod->state == MODULE_STATE_UNFORMED)
4372 continue;
4373 pr_cont(" %s%s", mod->name, module_flags(mod, buf));
4374 }
4375 preempt_enable();
4376 if (last_unloaded_module[0])
4377 pr_cont(" [last unloaded: %s]", last_unloaded_module);
4378 pr_cont("\n");
4379}
4380
4381#ifdef CONFIG_MODVERSIONS
4382/* Generate the signature for all relevant module structures here.
4383 * If these change, we don't want to try to parse the module. */
4384void module_layout(struct module *mod,
4385 struct modversion_info *ver,
4386 struct kernel_param *kp,
4387 struct kernel_symbol *ks,
4388 struct tracepoint * const *tp)
4389{
4390}
4391EXPORT_SYMBOL(module_layout);
4392#endif