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