]> git.proxmox.com Git - mirror_ubuntu-bionic-kernel.git/blob - kernel/module.c
Merge tag 'v4.3-rockchip32-dts3' of git://git.kernel.org/pub/scm/linux/kernel/git...
[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 /* Search for module by name: must hold module_mutex. */
606 static struct module *find_module_all(const char *name, size_t len,
607 bool even_unformed)
608 {
609 struct module *mod;
610
611 module_assert_mutex();
612
613 list_for_each_entry(mod, &modules, list) {
614 if (!even_unformed && mod->state == MODULE_STATE_UNFORMED)
615 continue;
616 if (strlen(mod->name) == len && !memcmp(mod->name, name, len))
617 return mod;
618 }
619 return NULL;
620 }
621
622 struct module *find_module(const char *name)
623 {
624 return find_module_all(name, strlen(name), false);
625 }
626 EXPORT_SYMBOL_GPL(find_module);
627
628 #ifdef CONFIG_SMP
629
630 static inline void __percpu *mod_percpu(struct module *mod)
631 {
632 return mod->percpu;
633 }
634
635 static int percpu_modalloc(struct module *mod, struct load_info *info)
636 {
637 Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu];
638 unsigned long align = pcpusec->sh_addralign;
639
640 if (!pcpusec->sh_size)
641 return 0;
642
643 if (align > PAGE_SIZE) {
644 pr_warn("%s: per-cpu alignment %li > %li\n",
645 mod->name, align, PAGE_SIZE);
646 align = PAGE_SIZE;
647 }
648
649 mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align);
650 if (!mod->percpu) {
651 pr_warn("%s: Could not allocate %lu bytes percpu data\n",
652 mod->name, (unsigned long)pcpusec->sh_size);
653 return -ENOMEM;
654 }
655 mod->percpu_size = pcpusec->sh_size;
656 return 0;
657 }
658
659 static void percpu_modfree(struct module *mod)
660 {
661 free_percpu(mod->percpu);
662 }
663
664 static unsigned int find_pcpusec(struct load_info *info)
665 {
666 return find_sec(info, ".data..percpu");
667 }
668
669 static void percpu_modcopy(struct module *mod,
670 const void *from, unsigned long size)
671 {
672 int cpu;
673
674 for_each_possible_cpu(cpu)
675 memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
676 }
677
678 /**
679 * is_module_percpu_address - test whether address is from module static percpu
680 * @addr: address to test
681 *
682 * Test whether @addr belongs to module static percpu area.
683 *
684 * RETURNS:
685 * %true if @addr is from module static percpu area
686 */
687 bool is_module_percpu_address(unsigned long addr)
688 {
689 struct module *mod;
690 unsigned int cpu;
691
692 preempt_disable();
693
694 list_for_each_entry_rcu(mod, &modules, list) {
695 if (mod->state == MODULE_STATE_UNFORMED)
696 continue;
697 if (!mod->percpu_size)
698 continue;
699 for_each_possible_cpu(cpu) {
700 void *start = per_cpu_ptr(mod->percpu, cpu);
701
702 if ((void *)addr >= start &&
703 (void *)addr < start + mod->percpu_size) {
704 preempt_enable();
705 return true;
706 }
707 }
708 }
709
710 preempt_enable();
711 return false;
712 }
713
714 #else /* ... !CONFIG_SMP */
715
716 static inline void __percpu *mod_percpu(struct module *mod)
717 {
718 return NULL;
719 }
720 static int percpu_modalloc(struct module *mod, struct load_info *info)
721 {
722 /* UP modules shouldn't have this section: ENOMEM isn't quite right */
723 if (info->sechdrs[info->index.pcpu].sh_size != 0)
724 return -ENOMEM;
725 return 0;
726 }
727 static inline void percpu_modfree(struct module *mod)
728 {
729 }
730 static unsigned int find_pcpusec(struct load_info *info)
731 {
732 return 0;
733 }
734 static inline void percpu_modcopy(struct module *mod,
735 const void *from, unsigned long size)
736 {
737 /* pcpusec should be 0, and size of that section should be 0. */
738 BUG_ON(size != 0);
739 }
740 bool is_module_percpu_address(unsigned long addr)
741 {
742 return false;
743 }
744
745 #endif /* CONFIG_SMP */
746
747 #define MODINFO_ATTR(field) \
748 static void setup_modinfo_##field(struct module *mod, const char *s) \
749 { \
750 mod->field = kstrdup(s, GFP_KERNEL); \
751 } \
752 static ssize_t show_modinfo_##field(struct module_attribute *mattr, \
753 struct module_kobject *mk, char *buffer) \
754 { \
755 return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field); \
756 } \
757 static int modinfo_##field##_exists(struct module *mod) \
758 { \
759 return mod->field != NULL; \
760 } \
761 static void free_modinfo_##field(struct module *mod) \
762 { \
763 kfree(mod->field); \
764 mod->field = NULL; \
765 } \
766 static struct module_attribute modinfo_##field = { \
767 .attr = { .name = __stringify(field), .mode = 0444 }, \
768 .show = show_modinfo_##field, \
769 .setup = setup_modinfo_##field, \
770 .test = modinfo_##field##_exists, \
771 .free = free_modinfo_##field, \
772 };
773
774 MODINFO_ATTR(version);
775 MODINFO_ATTR(srcversion);
776
777 static char last_unloaded_module[MODULE_NAME_LEN+1];
778
779 #ifdef CONFIG_MODULE_UNLOAD
780
781 EXPORT_TRACEPOINT_SYMBOL(module_get);
782
783 /* MODULE_REF_BASE is the base reference count by kmodule loader. */
784 #define MODULE_REF_BASE 1
785
786 /* Init the unload section of the module. */
787 static int module_unload_init(struct module *mod)
788 {
789 /*
790 * Initialize reference counter to MODULE_REF_BASE.
791 * refcnt == 0 means module is going.
792 */
793 atomic_set(&mod->refcnt, MODULE_REF_BASE);
794
795 INIT_LIST_HEAD(&mod->source_list);
796 INIT_LIST_HEAD(&mod->target_list);
797
798 /* Hold reference count during initialization. */
799 atomic_inc(&mod->refcnt);
800
801 return 0;
802 }
803
804 /* Does a already use b? */
805 static int already_uses(struct module *a, struct module *b)
806 {
807 struct module_use *use;
808
809 list_for_each_entry(use, &b->source_list, source_list) {
810 if (use->source == a) {
811 pr_debug("%s uses %s!\n", a->name, b->name);
812 return 1;
813 }
814 }
815 pr_debug("%s does not use %s!\n", a->name, b->name);
816 return 0;
817 }
818
819 /*
820 * Module a uses b
821 * - we add 'a' as a "source", 'b' as a "target" of module use
822 * - the module_use is added to the list of 'b' sources (so
823 * 'b' can walk the list to see who sourced them), and of 'a'
824 * targets (so 'a' can see what modules it targets).
825 */
826 static int add_module_usage(struct module *a, struct module *b)
827 {
828 struct module_use *use;
829
830 pr_debug("Allocating new usage for %s.\n", a->name);
831 use = kmalloc(sizeof(*use), GFP_ATOMIC);
832 if (!use) {
833 pr_warn("%s: out of memory loading\n", a->name);
834 return -ENOMEM;
835 }
836
837 use->source = a;
838 use->target = b;
839 list_add(&use->source_list, &b->source_list);
840 list_add(&use->target_list, &a->target_list);
841 return 0;
842 }
843
844 /* Module a uses b: caller needs module_mutex() */
845 int ref_module(struct module *a, struct module *b)
846 {
847 int err;
848
849 if (b == NULL || already_uses(a, b))
850 return 0;
851
852 /* If module isn't available, we fail. */
853 err = strong_try_module_get(b);
854 if (err)
855 return err;
856
857 err = add_module_usage(a, b);
858 if (err) {
859 module_put(b);
860 return err;
861 }
862 return 0;
863 }
864 EXPORT_SYMBOL_GPL(ref_module);
865
866 /* Clear the unload stuff of the module. */
867 static void module_unload_free(struct module *mod)
868 {
869 struct module_use *use, *tmp;
870
871 mutex_lock(&module_mutex);
872 list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
873 struct module *i = use->target;
874 pr_debug("%s unusing %s\n", mod->name, i->name);
875 module_put(i);
876 list_del(&use->source_list);
877 list_del(&use->target_list);
878 kfree(use);
879 }
880 mutex_unlock(&module_mutex);
881 }
882
883 #ifdef CONFIG_MODULE_FORCE_UNLOAD
884 static inline int try_force_unload(unsigned int flags)
885 {
886 int ret = (flags & O_TRUNC);
887 if (ret)
888 add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE);
889 return ret;
890 }
891 #else
892 static inline int try_force_unload(unsigned int flags)
893 {
894 return 0;
895 }
896 #endif /* CONFIG_MODULE_FORCE_UNLOAD */
897
898 /* Try to release refcount of module, 0 means success. */
899 static int try_release_module_ref(struct module *mod)
900 {
901 int ret;
902
903 /* Try to decrement refcnt which we set at loading */
904 ret = atomic_sub_return(MODULE_REF_BASE, &mod->refcnt);
905 BUG_ON(ret < 0);
906 if (ret)
907 /* Someone can put this right now, recover with checking */
908 ret = atomic_add_unless(&mod->refcnt, MODULE_REF_BASE, 0);
909
910 return ret;
911 }
912
913 static int try_stop_module(struct module *mod, int flags, int *forced)
914 {
915 /* If it's not unused, quit unless we're forcing. */
916 if (try_release_module_ref(mod) != 0) {
917 *forced = try_force_unload(flags);
918 if (!(*forced))
919 return -EWOULDBLOCK;
920 }
921
922 /* Mark it as dying. */
923 mod->state = MODULE_STATE_GOING;
924
925 return 0;
926 }
927
928 /**
929 * module_refcount - return the refcount or -1 if unloading
930 *
931 * @mod: the module we're checking
932 *
933 * Returns:
934 * -1 if the module is in the process of unloading
935 * otherwise the number of references in the kernel to the module
936 */
937 int module_refcount(struct module *mod)
938 {
939 return atomic_read(&mod->refcnt) - MODULE_REF_BASE;
940 }
941 EXPORT_SYMBOL(module_refcount);
942
943 /* This exists whether we can unload or not */
944 static void free_module(struct module *mod);
945
946 SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
947 unsigned int, flags)
948 {
949 struct module *mod;
950 char name[MODULE_NAME_LEN];
951 int ret, forced = 0;
952
953 if (!capable(CAP_SYS_MODULE) || modules_disabled)
954 return -EPERM;
955
956 if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
957 return -EFAULT;
958 name[MODULE_NAME_LEN-1] = '\0';
959
960 if (mutex_lock_interruptible(&module_mutex) != 0)
961 return -EINTR;
962
963 mod = find_module(name);
964 if (!mod) {
965 ret = -ENOENT;
966 goto out;
967 }
968
969 if (!list_empty(&mod->source_list)) {
970 /* Other modules depend on us: get rid of them first. */
971 ret = -EWOULDBLOCK;
972 goto out;
973 }
974
975 /* Doing init or already dying? */
976 if (mod->state != MODULE_STATE_LIVE) {
977 /* FIXME: if (force), slam module count damn the torpedoes */
978 pr_debug("%s already dying\n", mod->name);
979 ret = -EBUSY;
980 goto out;
981 }
982
983 /* If it has an init func, it must have an exit func to unload */
984 if (mod->init && !mod->exit) {
985 forced = try_force_unload(flags);
986 if (!forced) {
987 /* This module can't be removed */
988 ret = -EBUSY;
989 goto out;
990 }
991 }
992
993 /* Stop the machine so refcounts can't move and disable module. */
994 ret = try_stop_module(mod, flags, &forced);
995 if (ret != 0)
996 goto out;
997
998 mutex_unlock(&module_mutex);
999 /* Final destruction now no one is using it. */
1000 if (mod->exit != NULL)
1001 mod->exit();
1002 blocking_notifier_call_chain(&module_notify_list,
1003 MODULE_STATE_GOING, mod);
1004 async_synchronize_full();
1005
1006 /* Store the name of the last unloaded module for diagnostic purposes */
1007 strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
1008
1009 free_module(mod);
1010 return 0;
1011 out:
1012 mutex_unlock(&module_mutex);
1013 return ret;
1014 }
1015
1016 static inline void print_unload_info(struct seq_file *m, struct module *mod)
1017 {
1018 struct module_use *use;
1019 int printed_something = 0;
1020
1021 seq_printf(m, " %i ", module_refcount(mod));
1022
1023 /*
1024 * Always include a trailing , so userspace can differentiate
1025 * between this and the old multi-field proc format.
1026 */
1027 list_for_each_entry(use, &mod->source_list, source_list) {
1028 printed_something = 1;
1029 seq_printf(m, "%s,", use->source->name);
1030 }
1031
1032 if (mod->init != NULL && mod->exit == NULL) {
1033 printed_something = 1;
1034 seq_puts(m, "[permanent],");
1035 }
1036
1037 if (!printed_something)
1038 seq_puts(m, "-");
1039 }
1040
1041 void __symbol_put(const char *symbol)
1042 {
1043 struct module *owner;
1044
1045 preempt_disable();
1046 if (!find_symbol(symbol, &owner, NULL, true, false))
1047 BUG();
1048 module_put(owner);
1049 preempt_enable();
1050 }
1051 EXPORT_SYMBOL(__symbol_put);
1052
1053 /* Note this assumes addr is a function, which it currently always is. */
1054 void symbol_put_addr(void *addr)
1055 {
1056 struct module *modaddr;
1057 unsigned long a = (unsigned long)dereference_function_descriptor(addr);
1058
1059 if (core_kernel_text(a))
1060 return;
1061
1062 /* module_text_address is safe here: we're supposed to have reference
1063 * to module from symbol_get, so it can't go away. */
1064 modaddr = __module_text_address(a);
1065 BUG_ON(!modaddr);
1066 module_put(modaddr);
1067 }
1068 EXPORT_SYMBOL_GPL(symbol_put_addr);
1069
1070 static ssize_t show_refcnt(struct module_attribute *mattr,
1071 struct module_kobject *mk, char *buffer)
1072 {
1073 return sprintf(buffer, "%i\n", module_refcount(mk->mod));
1074 }
1075
1076 static struct module_attribute modinfo_refcnt =
1077 __ATTR(refcnt, 0444, show_refcnt, NULL);
1078
1079 void __module_get(struct module *module)
1080 {
1081 if (module) {
1082 preempt_disable();
1083 atomic_inc(&module->refcnt);
1084 trace_module_get(module, _RET_IP_);
1085 preempt_enable();
1086 }
1087 }
1088 EXPORT_SYMBOL(__module_get);
1089
1090 bool try_module_get(struct module *module)
1091 {
1092 bool ret = true;
1093
1094 if (module) {
1095 preempt_disable();
1096 /* Note: here, we can fail to get a reference */
1097 if (likely(module_is_live(module) &&
1098 atomic_inc_not_zero(&module->refcnt) != 0))
1099 trace_module_get(module, _RET_IP_);
1100 else
1101 ret = false;
1102
1103 preempt_enable();
1104 }
1105 return ret;
1106 }
1107 EXPORT_SYMBOL(try_module_get);
1108
1109 void module_put(struct module *module)
1110 {
1111 int ret;
1112
1113 if (module) {
1114 preempt_disable();
1115 ret = atomic_dec_if_positive(&module->refcnt);
1116 WARN_ON(ret < 0); /* Failed to put refcount */
1117 trace_module_put(module, _RET_IP_);
1118 preempt_enable();
1119 }
1120 }
1121 EXPORT_SYMBOL(module_put);
1122
1123 #else /* !CONFIG_MODULE_UNLOAD */
1124 static inline void print_unload_info(struct seq_file *m, struct module *mod)
1125 {
1126 /* We don't know the usage count, or what modules are using. */
1127 seq_puts(m, " - -");
1128 }
1129
1130 static inline void module_unload_free(struct module *mod)
1131 {
1132 }
1133
1134 int ref_module(struct module *a, struct module *b)
1135 {
1136 return strong_try_module_get(b);
1137 }
1138 EXPORT_SYMBOL_GPL(ref_module);
1139
1140 static inline int module_unload_init(struct module *mod)
1141 {
1142 return 0;
1143 }
1144 #endif /* CONFIG_MODULE_UNLOAD */
1145
1146 static size_t module_flags_taint(struct module *mod, char *buf)
1147 {
1148 size_t l = 0;
1149
1150 if (mod->taints & (1 << TAINT_PROPRIETARY_MODULE))
1151 buf[l++] = 'P';
1152 if (mod->taints & (1 << TAINT_OOT_MODULE))
1153 buf[l++] = 'O';
1154 if (mod->taints & (1 << TAINT_FORCED_MODULE))
1155 buf[l++] = 'F';
1156 if (mod->taints & (1 << TAINT_CRAP))
1157 buf[l++] = 'C';
1158 if (mod->taints & (1 << TAINT_UNSIGNED_MODULE))
1159 buf[l++] = 'E';
1160 /*
1161 * TAINT_FORCED_RMMOD: could be added.
1162 * TAINT_CPU_OUT_OF_SPEC, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't
1163 * apply to modules.
1164 */
1165 return l;
1166 }
1167
1168 static ssize_t show_initstate(struct module_attribute *mattr,
1169 struct module_kobject *mk, char *buffer)
1170 {
1171 const char *state = "unknown";
1172
1173 switch (mk->mod->state) {
1174 case MODULE_STATE_LIVE:
1175 state = "live";
1176 break;
1177 case MODULE_STATE_COMING:
1178 state = "coming";
1179 break;
1180 case MODULE_STATE_GOING:
1181 state = "going";
1182 break;
1183 default:
1184 BUG();
1185 }
1186 return sprintf(buffer, "%s\n", state);
1187 }
1188
1189 static struct module_attribute modinfo_initstate =
1190 __ATTR(initstate, 0444, show_initstate, NULL);
1191
1192 static ssize_t store_uevent(struct module_attribute *mattr,
1193 struct module_kobject *mk,
1194 const char *buffer, size_t count)
1195 {
1196 enum kobject_action action;
1197
1198 if (kobject_action_type(buffer, count, &action) == 0)
1199 kobject_uevent(&mk->kobj, action);
1200 return count;
1201 }
1202
1203 struct module_attribute module_uevent =
1204 __ATTR(uevent, 0200, NULL, store_uevent);
1205
1206 static ssize_t show_coresize(struct module_attribute *mattr,
1207 struct module_kobject *mk, char *buffer)
1208 {
1209 return sprintf(buffer, "%u\n", mk->mod->core_size);
1210 }
1211
1212 static struct module_attribute modinfo_coresize =
1213 __ATTR(coresize, 0444, show_coresize, NULL);
1214
1215 static ssize_t show_initsize(struct module_attribute *mattr,
1216 struct module_kobject *mk, char *buffer)
1217 {
1218 return sprintf(buffer, "%u\n", mk->mod->init_size);
1219 }
1220
1221 static struct module_attribute modinfo_initsize =
1222 __ATTR(initsize, 0444, show_initsize, NULL);
1223
1224 static ssize_t show_taint(struct module_attribute *mattr,
1225 struct module_kobject *mk, char *buffer)
1226 {
1227 size_t l;
1228
1229 l = module_flags_taint(mk->mod, buffer);
1230 buffer[l++] = '\n';
1231 return l;
1232 }
1233
1234 static struct module_attribute modinfo_taint =
1235 __ATTR(taint, 0444, show_taint, NULL);
1236
1237 static struct module_attribute *modinfo_attrs[] = {
1238 &module_uevent,
1239 &modinfo_version,
1240 &modinfo_srcversion,
1241 &modinfo_initstate,
1242 &modinfo_coresize,
1243 &modinfo_initsize,
1244 &modinfo_taint,
1245 #ifdef CONFIG_MODULE_UNLOAD
1246 &modinfo_refcnt,
1247 #endif
1248 NULL,
1249 };
1250
1251 static const char vermagic[] = VERMAGIC_STRING;
1252
1253 static int try_to_force_load(struct module *mod, const char *reason)
1254 {
1255 #ifdef CONFIG_MODULE_FORCE_LOAD
1256 if (!test_taint(TAINT_FORCED_MODULE))
1257 pr_warn("%s: %s: kernel tainted.\n", mod->name, reason);
1258 add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
1259 return 0;
1260 #else
1261 return -ENOEXEC;
1262 #endif
1263 }
1264
1265 #ifdef CONFIG_MODVERSIONS
1266 /* If the arch applies (non-zero) relocations to kernel kcrctab, unapply it. */
1267 static unsigned long maybe_relocated(unsigned long crc,
1268 const struct module *crc_owner)
1269 {
1270 #ifdef ARCH_RELOCATES_KCRCTAB
1271 if (crc_owner == NULL)
1272 return crc - (unsigned long)reloc_start;
1273 #endif
1274 return crc;
1275 }
1276
1277 static int check_version(Elf_Shdr *sechdrs,
1278 unsigned int versindex,
1279 const char *symname,
1280 struct module *mod,
1281 const unsigned long *crc,
1282 const struct module *crc_owner)
1283 {
1284 unsigned int i, num_versions;
1285 struct modversion_info *versions;
1286
1287 /* Exporting module didn't supply crcs? OK, we're already tainted. */
1288 if (!crc)
1289 return 1;
1290
1291 /* No versions at all? modprobe --force does this. */
1292 if (versindex == 0)
1293 return try_to_force_load(mod, symname) == 0;
1294
1295 versions = (void *) sechdrs[versindex].sh_addr;
1296 num_versions = sechdrs[versindex].sh_size
1297 / sizeof(struct modversion_info);
1298
1299 for (i = 0; i < num_versions; i++) {
1300 if (strcmp(versions[i].name, symname) != 0)
1301 continue;
1302
1303 if (versions[i].crc == maybe_relocated(*crc, crc_owner))
1304 return 1;
1305 pr_debug("Found checksum %lX vs module %lX\n",
1306 maybe_relocated(*crc, crc_owner), versions[i].crc);
1307 goto bad_version;
1308 }
1309
1310 pr_warn("%s: no symbol version for %s\n", mod->name, symname);
1311 return 0;
1312
1313 bad_version:
1314 pr_warn("%s: disagrees about version of symbol %s\n",
1315 mod->name, symname);
1316 return 0;
1317 }
1318
1319 static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1320 unsigned int versindex,
1321 struct module *mod)
1322 {
1323 const unsigned long *crc;
1324
1325 /*
1326 * Since this should be found in kernel (which can't be removed), no
1327 * locking is necessary -- use preempt_disable() to placate lockdep.
1328 */
1329 preempt_disable();
1330 if (!find_symbol(VMLINUX_SYMBOL_STR(module_layout), NULL,
1331 &crc, true, false)) {
1332 preempt_enable();
1333 BUG();
1334 }
1335 preempt_enable();
1336 return check_version(sechdrs, versindex,
1337 VMLINUX_SYMBOL_STR(module_layout), mod, crc,
1338 NULL);
1339 }
1340
1341 /* First part is kernel version, which we ignore if module has crcs. */
1342 static inline int same_magic(const char *amagic, const char *bmagic,
1343 bool has_crcs)
1344 {
1345 if (has_crcs) {
1346 amagic += strcspn(amagic, " ");
1347 bmagic += strcspn(bmagic, " ");
1348 }
1349 return strcmp(amagic, bmagic) == 0;
1350 }
1351 #else
1352 static inline int check_version(Elf_Shdr *sechdrs,
1353 unsigned int versindex,
1354 const char *symname,
1355 struct module *mod,
1356 const unsigned long *crc,
1357 const struct module *crc_owner)
1358 {
1359 return 1;
1360 }
1361
1362 static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1363 unsigned int versindex,
1364 struct module *mod)
1365 {
1366 return 1;
1367 }
1368
1369 static inline int same_magic(const char *amagic, const char *bmagic,
1370 bool has_crcs)
1371 {
1372 return strcmp(amagic, bmagic) == 0;
1373 }
1374 #endif /* CONFIG_MODVERSIONS */
1375
1376 /* Resolve a symbol for this module. I.e. if we find one, record usage. */
1377 static const struct kernel_symbol *resolve_symbol(struct module *mod,
1378 const struct load_info *info,
1379 const char *name,
1380 char ownername[])
1381 {
1382 struct module *owner;
1383 const struct kernel_symbol *sym;
1384 const unsigned long *crc;
1385 int err;
1386
1387 /*
1388 * The module_mutex should not be a heavily contended lock;
1389 * if we get the occasional sleep here, we'll go an extra iteration
1390 * in the wait_event_interruptible(), which is harmless.
1391 */
1392 sched_annotate_sleep();
1393 mutex_lock(&module_mutex);
1394 sym = find_symbol(name, &owner, &crc,
1395 !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
1396 if (!sym)
1397 goto unlock;
1398
1399 if (!check_version(info->sechdrs, info->index.vers, name, mod, crc,
1400 owner)) {
1401 sym = ERR_PTR(-EINVAL);
1402 goto getname;
1403 }
1404
1405 err = ref_module(mod, owner);
1406 if (err) {
1407 sym = ERR_PTR(err);
1408 goto getname;
1409 }
1410
1411 getname:
1412 /* We must make copy under the lock if we failed to get ref. */
1413 strncpy(ownername, module_name(owner), MODULE_NAME_LEN);
1414 unlock:
1415 mutex_unlock(&module_mutex);
1416 return sym;
1417 }
1418
1419 static const struct kernel_symbol *
1420 resolve_symbol_wait(struct module *mod,
1421 const struct load_info *info,
1422 const char *name)
1423 {
1424 const struct kernel_symbol *ksym;
1425 char owner[MODULE_NAME_LEN];
1426
1427 if (wait_event_interruptible_timeout(module_wq,
1428 !IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
1429 || PTR_ERR(ksym) != -EBUSY,
1430 30 * HZ) <= 0) {
1431 pr_warn("%s: gave up waiting for init of module %s.\n",
1432 mod->name, owner);
1433 }
1434 return ksym;
1435 }
1436
1437 /*
1438 * /sys/module/foo/sections stuff
1439 * J. Corbet <corbet@lwn.net>
1440 */
1441 #ifdef CONFIG_SYSFS
1442
1443 #ifdef CONFIG_KALLSYMS
1444 static inline bool sect_empty(const Elf_Shdr *sect)
1445 {
1446 return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
1447 }
1448
1449 struct module_sect_attr {
1450 struct module_attribute mattr;
1451 char *name;
1452 unsigned long address;
1453 };
1454
1455 struct module_sect_attrs {
1456 struct attribute_group grp;
1457 unsigned int nsections;
1458 struct module_sect_attr attrs[0];
1459 };
1460
1461 static ssize_t module_sect_show(struct module_attribute *mattr,
1462 struct module_kobject *mk, char *buf)
1463 {
1464 struct module_sect_attr *sattr =
1465 container_of(mattr, struct module_sect_attr, mattr);
1466 return sprintf(buf, "0x%pK\n", (void *)sattr->address);
1467 }
1468
1469 static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
1470 {
1471 unsigned int section;
1472
1473 for (section = 0; section < sect_attrs->nsections; section++)
1474 kfree(sect_attrs->attrs[section].name);
1475 kfree(sect_attrs);
1476 }
1477
1478 static void add_sect_attrs(struct module *mod, const struct load_info *info)
1479 {
1480 unsigned int nloaded = 0, i, size[2];
1481 struct module_sect_attrs *sect_attrs;
1482 struct module_sect_attr *sattr;
1483 struct attribute **gattr;
1484
1485 /* Count loaded sections and allocate structures */
1486 for (i = 0; i < info->hdr->e_shnum; i++)
1487 if (!sect_empty(&info->sechdrs[i]))
1488 nloaded++;
1489 size[0] = ALIGN(sizeof(*sect_attrs)
1490 + nloaded * sizeof(sect_attrs->attrs[0]),
1491 sizeof(sect_attrs->grp.attrs[0]));
1492 size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]);
1493 sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
1494 if (sect_attrs == NULL)
1495 return;
1496
1497 /* Setup section attributes. */
1498 sect_attrs->grp.name = "sections";
1499 sect_attrs->grp.attrs = (void *)sect_attrs + size[0];
1500
1501 sect_attrs->nsections = 0;
1502 sattr = &sect_attrs->attrs[0];
1503 gattr = &sect_attrs->grp.attrs[0];
1504 for (i = 0; i < info->hdr->e_shnum; i++) {
1505 Elf_Shdr *sec = &info->sechdrs[i];
1506 if (sect_empty(sec))
1507 continue;
1508 sattr->address = sec->sh_addr;
1509 sattr->name = kstrdup(info->secstrings + sec->sh_name,
1510 GFP_KERNEL);
1511 if (sattr->name == NULL)
1512 goto out;
1513 sect_attrs->nsections++;
1514 sysfs_attr_init(&sattr->mattr.attr);
1515 sattr->mattr.show = module_sect_show;
1516 sattr->mattr.store = NULL;
1517 sattr->mattr.attr.name = sattr->name;
1518 sattr->mattr.attr.mode = S_IRUGO;
1519 *(gattr++) = &(sattr++)->mattr.attr;
1520 }
1521 *gattr = NULL;
1522
1523 if (sysfs_create_group(&mod->mkobj.kobj, &sect_attrs->grp))
1524 goto out;
1525
1526 mod->sect_attrs = sect_attrs;
1527 return;
1528 out:
1529 free_sect_attrs(sect_attrs);
1530 }
1531
1532 static void remove_sect_attrs(struct module *mod)
1533 {
1534 if (mod->sect_attrs) {
1535 sysfs_remove_group(&mod->mkobj.kobj,
1536 &mod->sect_attrs->grp);
1537 /* We are positive that no one is using any sect attrs
1538 * at this point. Deallocate immediately. */
1539 free_sect_attrs(mod->sect_attrs);
1540 mod->sect_attrs = NULL;
1541 }
1542 }
1543
1544 /*
1545 * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
1546 */
1547
1548 struct module_notes_attrs {
1549 struct kobject *dir;
1550 unsigned int notes;
1551 struct bin_attribute attrs[0];
1552 };
1553
1554 static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
1555 struct bin_attribute *bin_attr,
1556 char *buf, loff_t pos, size_t count)
1557 {
1558 /*
1559 * The caller checked the pos and count against our size.
1560 */
1561 memcpy(buf, bin_attr->private + pos, count);
1562 return count;
1563 }
1564
1565 static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
1566 unsigned int i)
1567 {
1568 if (notes_attrs->dir) {
1569 while (i-- > 0)
1570 sysfs_remove_bin_file(notes_attrs->dir,
1571 &notes_attrs->attrs[i]);
1572 kobject_put(notes_attrs->dir);
1573 }
1574 kfree(notes_attrs);
1575 }
1576
1577 static void add_notes_attrs(struct module *mod, const struct load_info *info)
1578 {
1579 unsigned int notes, loaded, i;
1580 struct module_notes_attrs *notes_attrs;
1581 struct bin_attribute *nattr;
1582
1583 /* failed to create section attributes, so can't create notes */
1584 if (!mod->sect_attrs)
1585 return;
1586
1587 /* Count notes sections and allocate structures. */
1588 notes = 0;
1589 for (i = 0; i < info->hdr->e_shnum; i++)
1590 if (!sect_empty(&info->sechdrs[i]) &&
1591 (info->sechdrs[i].sh_type == SHT_NOTE))
1592 ++notes;
1593
1594 if (notes == 0)
1595 return;
1596
1597 notes_attrs = kzalloc(sizeof(*notes_attrs)
1598 + notes * sizeof(notes_attrs->attrs[0]),
1599 GFP_KERNEL);
1600 if (notes_attrs == NULL)
1601 return;
1602
1603 notes_attrs->notes = notes;
1604 nattr = &notes_attrs->attrs[0];
1605 for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
1606 if (sect_empty(&info->sechdrs[i]))
1607 continue;
1608 if (info->sechdrs[i].sh_type == SHT_NOTE) {
1609 sysfs_bin_attr_init(nattr);
1610 nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
1611 nattr->attr.mode = S_IRUGO;
1612 nattr->size = info->sechdrs[i].sh_size;
1613 nattr->private = (void *) info->sechdrs[i].sh_addr;
1614 nattr->read = module_notes_read;
1615 ++nattr;
1616 }
1617 ++loaded;
1618 }
1619
1620 notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
1621 if (!notes_attrs->dir)
1622 goto out;
1623
1624 for (i = 0; i < notes; ++i)
1625 if (sysfs_create_bin_file(notes_attrs->dir,
1626 &notes_attrs->attrs[i]))
1627 goto out;
1628
1629 mod->notes_attrs = notes_attrs;
1630 return;
1631
1632 out:
1633 free_notes_attrs(notes_attrs, i);
1634 }
1635
1636 static void remove_notes_attrs(struct module *mod)
1637 {
1638 if (mod->notes_attrs)
1639 free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
1640 }
1641
1642 #else
1643
1644 static inline void add_sect_attrs(struct module *mod,
1645 const struct load_info *info)
1646 {
1647 }
1648
1649 static inline void remove_sect_attrs(struct module *mod)
1650 {
1651 }
1652
1653 static inline void add_notes_attrs(struct module *mod,
1654 const struct load_info *info)
1655 {
1656 }
1657
1658 static inline void remove_notes_attrs(struct module *mod)
1659 {
1660 }
1661 #endif /* CONFIG_KALLSYMS */
1662
1663 static void add_usage_links(struct module *mod)
1664 {
1665 #ifdef CONFIG_MODULE_UNLOAD
1666 struct module_use *use;
1667 int nowarn;
1668
1669 mutex_lock(&module_mutex);
1670 list_for_each_entry(use, &mod->target_list, target_list) {
1671 nowarn = sysfs_create_link(use->target->holders_dir,
1672 &mod->mkobj.kobj, mod->name);
1673 }
1674 mutex_unlock(&module_mutex);
1675 #endif
1676 }
1677
1678 static void del_usage_links(struct module *mod)
1679 {
1680 #ifdef CONFIG_MODULE_UNLOAD
1681 struct module_use *use;
1682
1683 mutex_lock(&module_mutex);
1684 list_for_each_entry(use, &mod->target_list, target_list)
1685 sysfs_remove_link(use->target->holders_dir, mod->name);
1686 mutex_unlock(&module_mutex);
1687 #endif
1688 }
1689
1690 static int module_add_modinfo_attrs(struct module *mod)
1691 {
1692 struct module_attribute *attr;
1693 struct module_attribute *temp_attr;
1694 int error = 0;
1695 int i;
1696
1697 mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
1698 (ARRAY_SIZE(modinfo_attrs) + 1)),
1699 GFP_KERNEL);
1700 if (!mod->modinfo_attrs)
1701 return -ENOMEM;
1702
1703 temp_attr = mod->modinfo_attrs;
1704 for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
1705 if (!attr->test ||
1706 (attr->test && attr->test(mod))) {
1707 memcpy(temp_attr, attr, sizeof(*temp_attr));
1708 sysfs_attr_init(&temp_attr->attr);
1709 error = sysfs_create_file(&mod->mkobj.kobj,
1710 &temp_attr->attr);
1711 ++temp_attr;
1712 }
1713 }
1714 return error;
1715 }
1716
1717 static void module_remove_modinfo_attrs(struct module *mod)
1718 {
1719 struct module_attribute *attr;
1720 int i;
1721
1722 for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
1723 /* pick a field to test for end of list */
1724 if (!attr->attr.name)
1725 break;
1726 sysfs_remove_file(&mod->mkobj.kobj, &attr->attr);
1727 if (attr->free)
1728 attr->free(mod);
1729 }
1730 kfree(mod->modinfo_attrs);
1731 }
1732
1733 static void mod_kobject_put(struct module *mod)
1734 {
1735 DECLARE_COMPLETION_ONSTACK(c);
1736 mod->mkobj.kobj_completion = &c;
1737 kobject_put(&mod->mkobj.kobj);
1738 wait_for_completion(&c);
1739 }
1740
1741 static int mod_sysfs_init(struct module *mod)
1742 {
1743 int err;
1744 struct kobject *kobj;
1745
1746 if (!module_sysfs_initialized) {
1747 pr_err("%s: module sysfs not initialized\n", mod->name);
1748 err = -EINVAL;
1749 goto out;
1750 }
1751
1752 kobj = kset_find_obj(module_kset, mod->name);
1753 if (kobj) {
1754 pr_err("%s: module is already loaded\n", mod->name);
1755 kobject_put(kobj);
1756 err = -EINVAL;
1757 goto out;
1758 }
1759
1760 mod->mkobj.mod = mod;
1761
1762 memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
1763 mod->mkobj.kobj.kset = module_kset;
1764 err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
1765 "%s", mod->name);
1766 if (err)
1767 mod_kobject_put(mod);
1768
1769 /* delay uevent until full sysfs population */
1770 out:
1771 return err;
1772 }
1773
1774 static int mod_sysfs_setup(struct module *mod,
1775 const struct load_info *info,
1776 struct kernel_param *kparam,
1777 unsigned int num_params)
1778 {
1779 int err;
1780
1781 err = mod_sysfs_init(mod);
1782 if (err)
1783 goto out;
1784
1785 mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1786 if (!mod->holders_dir) {
1787 err = -ENOMEM;
1788 goto out_unreg;
1789 }
1790
1791 err = module_param_sysfs_setup(mod, kparam, num_params);
1792 if (err)
1793 goto out_unreg_holders;
1794
1795 err = module_add_modinfo_attrs(mod);
1796 if (err)
1797 goto out_unreg_param;
1798
1799 add_usage_links(mod);
1800 add_sect_attrs(mod, info);
1801 add_notes_attrs(mod, info);
1802
1803 kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
1804 return 0;
1805
1806 out_unreg_param:
1807 module_param_sysfs_remove(mod);
1808 out_unreg_holders:
1809 kobject_put(mod->holders_dir);
1810 out_unreg:
1811 mod_kobject_put(mod);
1812 out:
1813 return err;
1814 }
1815
1816 static void mod_sysfs_fini(struct module *mod)
1817 {
1818 remove_notes_attrs(mod);
1819 remove_sect_attrs(mod);
1820 mod_kobject_put(mod);
1821 }
1822
1823 static void init_param_lock(struct module *mod)
1824 {
1825 mutex_init(&mod->param_lock);
1826 }
1827 #else /* !CONFIG_SYSFS */
1828
1829 static int mod_sysfs_setup(struct module *mod,
1830 const struct load_info *info,
1831 struct kernel_param *kparam,
1832 unsigned int num_params)
1833 {
1834 return 0;
1835 }
1836
1837 static void mod_sysfs_fini(struct module *mod)
1838 {
1839 }
1840
1841 static void module_remove_modinfo_attrs(struct module *mod)
1842 {
1843 }
1844
1845 static void del_usage_links(struct module *mod)
1846 {
1847 }
1848
1849 static void init_param_lock(struct module *mod)
1850 {
1851 }
1852 #endif /* CONFIG_SYSFS */
1853
1854 static void mod_sysfs_teardown(struct module *mod)
1855 {
1856 del_usage_links(mod);
1857 module_remove_modinfo_attrs(mod);
1858 module_param_sysfs_remove(mod);
1859 kobject_put(mod->mkobj.drivers_dir);
1860 kobject_put(mod->holders_dir);
1861 mod_sysfs_fini(mod);
1862 }
1863
1864 #ifdef CONFIG_DEBUG_SET_MODULE_RONX
1865 /*
1866 * LKM RO/NX protection: protect module's text/ro-data
1867 * from modification and any data from execution.
1868 */
1869 void set_page_attributes(void *start, void *end, int (*set)(unsigned long start, int num_pages))
1870 {
1871 unsigned long begin_pfn = PFN_DOWN((unsigned long)start);
1872 unsigned long end_pfn = PFN_DOWN((unsigned long)end);
1873
1874 if (end_pfn > begin_pfn)
1875 set(begin_pfn << PAGE_SHIFT, end_pfn - begin_pfn);
1876 }
1877
1878 static void set_section_ro_nx(void *base,
1879 unsigned long text_size,
1880 unsigned long ro_size,
1881 unsigned long total_size)
1882 {
1883 /* begin and end PFNs of the current subsection */
1884 unsigned long begin_pfn;
1885 unsigned long end_pfn;
1886
1887 /*
1888 * Set RO for module text and RO-data:
1889 * - Always protect first page.
1890 * - Do not protect last partial page.
1891 */
1892 if (ro_size > 0)
1893 set_page_attributes(base, base + ro_size, set_memory_ro);
1894
1895 /*
1896 * Set NX permissions for module data:
1897 * - Do not protect first partial page.
1898 * - Always protect last page.
1899 */
1900 if (total_size > text_size) {
1901 begin_pfn = PFN_UP((unsigned long)base + text_size);
1902 end_pfn = PFN_UP((unsigned long)base + total_size);
1903 if (end_pfn > begin_pfn)
1904 set_memory_nx(begin_pfn << PAGE_SHIFT, end_pfn - begin_pfn);
1905 }
1906 }
1907
1908 static void unset_module_core_ro_nx(struct module *mod)
1909 {
1910 set_page_attributes(mod->module_core + mod->core_text_size,
1911 mod->module_core + mod->core_size,
1912 set_memory_x);
1913 set_page_attributes(mod->module_core,
1914 mod->module_core + mod->core_ro_size,
1915 set_memory_rw);
1916 }
1917
1918 static void unset_module_init_ro_nx(struct module *mod)
1919 {
1920 set_page_attributes(mod->module_init + mod->init_text_size,
1921 mod->module_init + mod->init_size,
1922 set_memory_x);
1923 set_page_attributes(mod->module_init,
1924 mod->module_init + mod->init_ro_size,
1925 set_memory_rw);
1926 }
1927
1928 /* Iterate through all modules and set each module's text as RW */
1929 void set_all_modules_text_rw(void)
1930 {
1931 struct module *mod;
1932
1933 mutex_lock(&module_mutex);
1934 list_for_each_entry_rcu(mod, &modules, list) {
1935 if (mod->state == MODULE_STATE_UNFORMED)
1936 continue;
1937 if ((mod->module_core) && (mod->core_text_size)) {
1938 set_page_attributes(mod->module_core,
1939 mod->module_core + mod->core_text_size,
1940 set_memory_rw);
1941 }
1942 if ((mod->module_init) && (mod->init_text_size)) {
1943 set_page_attributes(mod->module_init,
1944 mod->module_init + mod->init_text_size,
1945 set_memory_rw);
1946 }
1947 }
1948 mutex_unlock(&module_mutex);
1949 }
1950
1951 /* Iterate through all modules and set each module's text as RO */
1952 void set_all_modules_text_ro(void)
1953 {
1954 struct module *mod;
1955
1956 mutex_lock(&module_mutex);
1957 list_for_each_entry_rcu(mod, &modules, list) {
1958 if (mod->state == MODULE_STATE_UNFORMED)
1959 continue;
1960 if ((mod->module_core) && (mod->core_text_size)) {
1961 set_page_attributes(mod->module_core,
1962 mod->module_core + mod->core_text_size,
1963 set_memory_ro);
1964 }
1965 if ((mod->module_init) && (mod->init_text_size)) {
1966 set_page_attributes(mod->module_init,
1967 mod->module_init + mod->init_text_size,
1968 set_memory_ro);
1969 }
1970 }
1971 mutex_unlock(&module_mutex);
1972 }
1973 #else
1974 static inline void set_section_ro_nx(void *base, unsigned long text_size, unsigned long ro_size, unsigned long total_size) { }
1975 static void unset_module_core_ro_nx(struct module *mod) { }
1976 static void unset_module_init_ro_nx(struct module *mod) { }
1977 #endif
1978
1979 void __weak module_memfree(void *module_region)
1980 {
1981 vfree(module_region);
1982 }
1983
1984 void __weak module_arch_cleanup(struct module *mod)
1985 {
1986 }
1987
1988 void __weak module_arch_freeing_init(struct module *mod)
1989 {
1990 }
1991
1992 /* Free a module, remove from lists, etc. */
1993 static void free_module(struct module *mod)
1994 {
1995 trace_module_free(mod);
1996
1997 mod_sysfs_teardown(mod);
1998
1999 /* We leave it in list to prevent duplicate loads, but make sure
2000 * that noone uses it while it's being deconstructed. */
2001 mutex_lock(&module_mutex);
2002 mod->state = MODULE_STATE_UNFORMED;
2003 mutex_unlock(&module_mutex);
2004
2005 /* Remove dynamic debug info */
2006 ddebug_remove_module(mod->name);
2007
2008 /* Arch-specific cleanup. */
2009 module_arch_cleanup(mod);
2010
2011 /* Module unload stuff */
2012 module_unload_free(mod);
2013
2014 /* Free any allocated parameters. */
2015 destroy_params(mod->kp, mod->num_kp);
2016
2017 /* Now we can delete it from the lists */
2018 mutex_lock(&module_mutex);
2019 /* Unlink carefully: kallsyms could be walking list. */
2020 list_del_rcu(&mod->list);
2021 mod_tree_remove(mod);
2022 /* Remove this module from bug list, this uses list_del_rcu */
2023 module_bug_cleanup(mod);
2024 /* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */
2025 synchronize_sched();
2026 mutex_unlock(&module_mutex);
2027
2028 /* This may be NULL, but that's OK */
2029 unset_module_init_ro_nx(mod);
2030 module_arch_freeing_init(mod);
2031 module_memfree(mod->module_init);
2032 kfree(mod->args);
2033 percpu_modfree(mod);
2034
2035 /* Free lock-classes; relies on the preceding sync_rcu(). */
2036 lockdep_free_key_range(mod->module_core, mod->core_size);
2037
2038 /* Finally, free the core (containing the module structure) */
2039 unset_module_core_ro_nx(mod);
2040 module_memfree(mod->module_core);
2041
2042 #ifdef CONFIG_MPU
2043 update_protections(current->mm);
2044 #endif
2045 }
2046
2047 void *__symbol_get(const char *symbol)
2048 {
2049 struct module *owner;
2050 const struct kernel_symbol *sym;
2051
2052 preempt_disable();
2053 sym = find_symbol(symbol, &owner, NULL, true, true);
2054 if (sym && strong_try_module_get(owner))
2055 sym = NULL;
2056 preempt_enable();
2057
2058 return sym ? (void *)sym->value : NULL;
2059 }
2060 EXPORT_SYMBOL_GPL(__symbol_get);
2061
2062 /*
2063 * Ensure that an exported symbol [global namespace] does not already exist
2064 * in the kernel or in some other module's exported symbol table.
2065 *
2066 * You must hold the module_mutex.
2067 */
2068 static int verify_export_symbols(struct module *mod)
2069 {
2070 unsigned int i;
2071 struct module *owner;
2072 const struct kernel_symbol *s;
2073 struct {
2074 const struct kernel_symbol *sym;
2075 unsigned int num;
2076 } arr[] = {
2077 { mod->syms, mod->num_syms },
2078 { mod->gpl_syms, mod->num_gpl_syms },
2079 { mod->gpl_future_syms, mod->num_gpl_future_syms },
2080 #ifdef CONFIG_UNUSED_SYMBOLS
2081 { mod->unused_syms, mod->num_unused_syms },
2082 { mod->unused_gpl_syms, mod->num_unused_gpl_syms },
2083 #endif
2084 };
2085
2086 for (i = 0; i < ARRAY_SIZE(arr); i++) {
2087 for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
2088 if (find_symbol(s->name, &owner, NULL, true, false)) {
2089 pr_err("%s: exports duplicate symbol %s"
2090 " (owned by %s)\n",
2091 mod->name, s->name, module_name(owner));
2092 return -ENOEXEC;
2093 }
2094 }
2095 }
2096 return 0;
2097 }
2098
2099 /* Change all symbols so that st_value encodes the pointer directly. */
2100 static int simplify_symbols(struct module *mod, const struct load_info *info)
2101 {
2102 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2103 Elf_Sym *sym = (void *)symsec->sh_addr;
2104 unsigned long secbase;
2105 unsigned int i;
2106 int ret = 0;
2107 const struct kernel_symbol *ksym;
2108
2109 for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
2110 const char *name = info->strtab + sym[i].st_name;
2111
2112 switch (sym[i].st_shndx) {
2113 case SHN_COMMON:
2114 /* Ignore common symbols */
2115 if (!strncmp(name, "__gnu_lto", 9))
2116 break;
2117
2118 /* We compiled with -fno-common. These are not
2119 supposed to happen. */
2120 pr_debug("Common symbol: %s\n", name);
2121 pr_warn("%s: please compile with -fno-common\n",
2122 mod->name);
2123 ret = -ENOEXEC;
2124 break;
2125
2126 case SHN_ABS:
2127 /* Don't need to do anything */
2128 pr_debug("Absolute symbol: 0x%08lx\n",
2129 (long)sym[i].st_value);
2130 break;
2131
2132 case SHN_UNDEF:
2133 ksym = resolve_symbol_wait(mod, info, name);
2134 /* Ok if resolved. */
2135 if (ksym && !IS_ERR(ksym)) {
2136 sym[i].st_value = ksym->value;
2137 break;
2138 }
2139
2140 /* Ok if weak. */
2141 if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
2142 break;
2143
2144 pr_warn("%s: Unknown symbol %s (err %li)\n",
2145 mod->name, name, PTR_ERR(ksym));
2146 ret = PTR_ERR(ksym) ?: -ENOENT;
2147 break;
2148
2149 default:
2150 /* Divert to percpu allocation if a percpu var. */
2151 if (sym[i].st_shndx == info->index.pcpu)
2152 secbase = (unsigned long)mod_percpu(mod);
2153 else
2154 secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
2155 sym[i].st_value += secbase;
2156 break;
2157 }
2158 }
2159
2160 return ret;
2161 }
2162
2163 static int apply_relocations(struct module *mod, const struct load_info *info)
2164 {
2165 unsigned int i;
2166 int err = 0;
2167
2168 /* Now do relocations. */
2169 for (i = 1; i < info->hdr->e_shnum; i++) {
2170 unsigned int infosec = info->sechdrs[i].sh_info;
2171
2172 /* Not a valid relocation section? */
2173 if (infosec >= info->hdr->e_shnum)
2174 continue;
2175
2176 /* Don't bother with non-allocated sections */
2177 if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
2178 continue;
2179
2180 if (info->sechdrs[i].sh_type == SHT_REL)
2181 err = apply_relocate(info->sechdrs, info->strtab,
2182 info->index.sym, i, mod);
2183 else if (info->sechdrs[i].sh_type == SHT_RELA)
2184 err = apply_relocate_add(info->sechdrs, info->strtab,
2185 info->index.sym, i, mod);
2186 if (err < 0)
2187 break;
2188 }
2189 return err;
2190 }
2191
2192 /* Additional bytes needed by arch in front of individual sections */
2193 unsigned int __weak arch_mod_section_prepend(struct module *mod,
2194 unsigned int section)
2195 {
2196 /* default implementation just returns zero */
2197 return 0;
2198 }
2199
2200 /* Update size with this section: return offset. */
2201 static long get_offset(struct module *mod, unsigned int *size,
2202 Elf_Shdr *sechdr, unsigned int section)
2203 {
2204 long ret;
2205
2206 *size += arch_mod_section_prepend(mod, section);
2207 ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
2208 *size = ret + sechdr->sh_size;
2209 return ret;
2210 }
2211
2212 /* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
2213 might -- code, read-only data, read-write data, small data. Tally
2214 sizes, and place the offsets into sh_entsize fields: high bit means it
2215 belongs in init. */
2216 static void layout_sections(struct module *mod, struct load_info *info)
2217 {
2218 static unsigned long const masks[][2] = {
2219 /* NOTE: all executable code must be the first section
2220 * in this array; otherwise modify the text_size
2221 * finder in the two loops below */
2222 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
2223 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
2224 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
2225 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
2226 };
2227 unsigned int m, i;
2228
2229 for (i = 0; i < info->hdr->e_shnum; i++)
2230 info->sechdrs[i].sh_entsize = ~0UL;
2231
2232 pr_debug("Core section allocation order:\n");
2233 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2234 for (i = 0; i < info->hdr->e_shnum; ++i) {
2235 Elf_Shdr *s = &info->sechdrs[i];
2236 const char *sname = info->secstrings + s->sh_name;
2237
2238 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2239 || (s->sh_flags & masks[m][1])
2240 || s->sh_entsize != ~0UL
2241 || strstarts(sname, ".init"))
2242 continue;
2243 s->sh_entsize = get_offset(mod, &mod->core_size, s, i);
2244 pr_debug("\t%s\n", sname);
2245 }
2246 switch (m) {
2247 case 0: /* executable */
2248 mod->core_size = debug_align(mod->core_size);
2249 mod->core_text_size = mod->core_size;
2250 break;
2251 case 1: /* RO: text and ro-data */
2252 mod->core_size = debug_align(mod->core_size);
2253 mod->core_ro_size = mod->core_size;
2254 break;
2255 case 3: /* whole core */
2256 mod->core_size = debug_align(mod->core_size);
2257 break;
2258 }
2259 }
2260
2261 pr_debug("Init section allocation order:\n");
2262 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2263 for (i = 0; i < info->hdr->e_shnum; ++i) {
2264 Elf_Shdr *s = &info->sechdrs[i];
2265 const char *sname = info->secstrings + s->sh_name;
2266
2267 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2268 || (s->sh_flags & masks[m][1])
2269 || s->sh_entsize != ~0UL
2270 || !strstarts(sname, ".init"))
2271 continue;
2272 s->sh_entsize = (get_offset(mod, &mod->init_size, s, i)
2273 | INIT_OFFSET_MASK);
2274 pr_debug("\t%s\n", sname);
2275 }
2276 switch (m) {
2277 case 0: /* executable */
2278 mod->init_size = debug_align(mod->init_size);
2279 mod->init_text_size = mod->init_size;
2280 break;
2281 case 1: /* RO: text and ro-data */
2282 mod->init_size = debug_align(mod->init_size);
2283 mod->init_ro_size = mod->init_size;
2284 break;
2285 case 3: /* whole init */
2286 mod->init_size = debug_align(mod->init_size);
2287 break;
2288 }
2289 }
2290 }
2291
2292 static void set_license(struct module *mod, const char *license)
2293 {
2294 if (!license)
2295 license = "unspecified";
2296
2297 if (!license_is_gpl_compatible(license)) {
2298 if (!test_taint(TAINT_PROPRIETARY_MODULE))
2299 pr_warn("%s: module license '%s' taints kernel.\n",
2300 mod->name, license);
2301 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2302 LOCKDEP_NOW_UNRELIABLE);
2303 }
2304 }
2305
2306 /* Parse tag=value strings from .modinfo section */
2307 static char *next_string(char *string, unsigned long *secsize)
2308 {
2309 /* Skip non-zero chars */
2310 while (string[0]) {
2311 string++;
2312 if ((*secsize)-- <= 1)
2313 return NULL;
2314 }
2315
2316 /* Skip any zero padding. */
2317 while (!string[0]) {
2318 string++;
2319 if ((*secsize)-- <= 1)
2320 return NULL;
2321 }
2322 return string;
2323 }
2324
2325 static char *get_modinfo(struct load_info *info, const char *tag)
2326 {
2327 char *p;
2328 unsigned int taglen = strlen(tag);
2329 Elf_Shdr *infosec = &info->sechdrs[info->index.info];
2330 unsigned long size = infosec->sh_size;
2331
2332 for (p = (char *)infosec->sh_addr; p; p = next_string(p, &size)) {
2333 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
2334 return p + taglen + 1;
2335 }
2336 return NULL;
2337 }
2338
2339 static void setup_modinfo(struct module *mod, struct load_info *info)
2340 {
2341 struct module_attribute *attr;
2342 int i;
2343
2344 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2345 if (attr->setup)
2346 attr->setup(mod, get_modinfo(info, attr->attr.name));
2347 }
2348 }
2349
2350 static void free_modinfo(struct module *mod)
2351 {
2352 struct module_attribute *attr;
2353 int i;
2354
2355 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2356 if (attr->free)
2357 attr->free(mod);
2358 }
2359 }
2360
2361 #ifdef CONFIG_KALLSYMS
2362
2363 /* lookup symbol in given range of kernel_symbols */
2364 static const struct kernel_symbol *lookup_symbol(const char *name,
2365 const struct kernel_symbol *start,
2366 const struct kernel_symbol *stop)
2367 {
2368 return bsearch(name, start, stop - start,
2369 sizeof(struct kernel_symbol), cmp_name);
2370 }
2371
2372 static int is_exported(const char *name, unsigned long value,
2373 const struct module *mod)
2374 {
2375 const struct kernel_symbol *ks;
2376 if (!mod)
2377 ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
2378 else
2379 ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
2380 return ks != NULL && ks->value == value;
2381 }
2382
2383 /* As per nm */
2384 static char elf_type(const Elf_Sym *sym, const struct load_info *info)
2385 {
2386 const Elf_Shdr *sechdrs = info->sechdrs;
2387
2388 if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
2389 if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
2390 return 'v';
2391 else
2392 return 'w';
2393 }
2394 if (sym->st_shndx == SHN_UNDEF)
2395 return 'U';
2396 if (sym->st_shndx == SHN_ABS)
2397 return 'a';
2398 if (sym->st_shndx >= SHN_LORESERVE)
2399 return '?';
2400 if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
2401 return 't';
2402 if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
2403 && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
2404 if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
2405 return 'r';
2406 else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2407 return 'g';
2408 else
2409 return 'd';
2410 }
2411 if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
2412 if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2413 return 's';
2414 else
2415 return 'b';
2416 }
2417 if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
2418 ".debug")) {
2419 return 'n';
2420 }
2421 return '?';
2422 }
2423
2424 static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
2425 unsigned int shnum)
2426 {
2427 const Elf_Shdr *sec;
2428
2429 if (src->st_shndx == SHN_UNDEF
2430 || src->st_shndx >= shnum
2431 || !src->st_name)
2432 return false;
2433
2434 sec = sechdrs + src->st_shndx;
2435 if (!(sec->sh_flags & SHF_ALLOC)
2436 #ifndef CONFIG_KALLSYMS_ALL
2437 || !(sec->sh_flags & SHF_EXECINSTR)
2438 #endif
2439 || (sec->sh_entsize & INIT_OFFSET_MASK))
2440 return false;
2441
2442 return true;
2443 }
2444
2445 /*
2446 * We only allocate and copy the strings needed by the parts of symtab
2447 * we keep. This is simple, but has the effect of making multiple
2448 * copies of duplicates. We could be more sophisticated, see
2449 * linux-kernel thread starting with
2450 * <73defb5e4bca04a6431392cc341112b1@localhost>.
2451 */
2452 static void layout_symtab(struct module *mod, struct load_info *info)
2453 {
2454 Elf_Shdr *symsect = info->sechdrs + info->index.sym;
2455 Elf_Shdr *strsect = info->sechdrs + info->index.str;
2456 const Elf_Sym *src;
2457 unsigned int i, nsrc, ndst, strtab_size = 0;
2458
2459 /* Put symbol section at end of init part of module. */
2460 symsect->sh_flags |= SHF_ALLOC;
2461 symsect->sh_entsize = get_offset(mod, &mod->init_size, symsect,
2462 info->index.sym) | INIT_OFFSET_MASK;
2463 pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
2464
2465 src = (void *)info->hdr + symsect->sh_offset;
2466 nsrc = symsect->sh_size / sizeof(*src);
2467
2468 /* Compute total space required for the core symbols' strtab. */
2469 for (ndst = i = 0; i < nsrc; i++) {
2470 if (i == 0 ||
2471 is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum)) {
2472 strtab_size += strlen(&info->strtab[src[i].st_name])+1;
2473 ndst++;
2474 }
2475 }
2476
2477 /* Append room for core symbols at end of core part. */
2478 info->symoffs = ALIGN(mod->core_size, symsect->sh_addralign ?: 1);
2479 info->stroffs = mod->core_size = info->symoffs + ndst * sizeof(Elf_Sym);
2480 mod->core_size += strtab_size;
2481 mod->core_size = debug_align(mod->core_size);
2482
2483 /* Put string table section at end of init part of module. */
2484 strsect->sh_flags |= SHF_ALLOC;
2485 strsect->sh_entsize = get_offset(mod, &mod->init_size, strsect,
2486 info->index.str) | INIT_OFFSET_MASK;
2487 mod->init_size = debug_align(mod->init_size);
2488 pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
2489 }
2490
2491 static void add_kallsyms(struct module *mod, const struct load_info *info)
2492 {
2493 unsigned int i, ndst;
2494 const Elf_Sym *src;
2495 Elf_Sym *dst;
2496 char *s;
2497 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2498
2499 mod->symtab = (void *)symsec->sh_addr;
2500 mod->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
2501 /* Make sure we get permanent strtab: don't use info->strtab. */
2502 mod->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
2503
2504 /* Set types up while we still have access to sections. */
2505 for (i = 0; i < mod->num_symtab; i++)
2506 mod->symtab[i].st_info = elf_type(&mod->symtab[i], info);
2507
2508 mod->core_symtab = dst = mod->module_core + info->symoffs;
2509 mod->core_strtab = s = mod->module_core + info->stroffs;
2510 src = mod->symtab;
2511 for (ndst = i = 0; i < mod->num_symtab; i++) {
2512 if (i == 0 ||
2513 is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum)) {
2514 dst[ndst] = src[i];
2515 dst[ndst++].st_name = s - mod->core_strtab;
2516 s += strlcpy(s, &mod->strtab[src[i].st_name],
2517 KSYM_NAME_LEN) + 1;
2518 }
2519 }
2520 mod->core_num_syms = ndst;
2521 }
2522 #else
2523 static inline void layout_symtab(struct module *mod, struct load_info *info)
2524 {
2525 }
2526
2527 static void add_kallsyms(struct module *mod, const struct load_info *info)
2528 {
2529 }
2530 #endif /* CONFIG_KALLSYMS */
2531
2532 static void dynamic_debug_setup(struct _ddebug *debug, unsigned int num)
2533 {
2534 if (!debug)
2535 return;
2536 #ifdef CONFIG_DYNAMIC_DEBUG
2537 if (ddebug_add_module(debug, num, debug->modname))
2538 pr_err("dynamic debug error adding module: %s\n",
2539 debug->modname);
2540 #endif
2541 }
2542
2543 static void dynamic_debug_remove(struct _ddebug *debug)
2544 {
2545 if (debug)
2546 ddebug_remove_module(debug->modname);
2547 }
2548
2549 void * __weak module_alloc(unsigned long size)
2550 {
2551 return vmalloc_exec(size);
2552 }
2553
2554 #ifdef CONFIG_DEBUG_KMEMLEAK
2555 static void kmemleak_load_module(const struct module *mod,
2556 const struct load_info *info)
2557 {
2558 unsigned int i;
2559
2560 /* only scan the sections containing data */
2561 kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
2562
2563 for (i = 1; i < info->hdr->e_shnum; i++) {
2564 /* Scan all writable sections that's not executable */
2565 if (!(info->sechdrs[i].sh_flags & SHF_ALLOC) ||
2566 !(info->sechdrs[i].sh_flags & SHF_WRITE) ||
2567 (info->sechdrs[i].sh_flags & SHF_EXECINSTR))
2568 continue;
2569
2570 kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
2571 info->sechdrs[i].sh_size, GFP_KERNEL);
2572 }
2573 }
2574 #else
2575 static inline void kmemleak_load_module(const struct module *mod,
2576 const struct load_info *info)
2577 {
2578 }
2579 #endif
2580
2581 #ifdef CONFIG_MODULE_SIG
2582 static int module_sig_check(struct load_info *info)
2583 {
2584 int err = -ENOKEY;
2585 const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
2586 const void *mod = info->hdr;
2587
2588 if (info->len > markerlen &&
2589 memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
2590 /* We truncate the module to discard the signature */
2591 info->len -= markerlen;
2592 err = mod_verify_sig(mod, &info->len);
2593 }
2594
2595 if (!err) {
2596 info->sig_ok = true;
2597 return 0;
2598 }
2599
2600 /* Not having a signature is only an error if we're strict. */
2601 if (err == -ENOKEY && !sig_enforce)
2602 err = 0;
2603
2604 return err;
2605 }
2606 #else /* !CONFIG_MODULE_SIG */
2607 static int module_sig_check(struct load_info *info)
2608 {
2609 return 0;
2610 }
2611 #endif /* !CONFIG_MODULE_SIG */
2612
2613 /* Sanity checks against invalid binaries, wrong arch, weird elf version. */
2614 static int elf_header_check(struct load_info *info)
2615 {
2616 if (info->len < sizeof(*(info->hdr)))
2617 return -ENOEXEC;
2618
2619 if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0
2620 || info->hdr->e_type != ET_REL
2621 || !elf_check_arch(info->hdr)
2622 || info->hdr->e_shentsize != sizeof(Elf_Shdr))
2623 return -ENOEXEC;
2624
2625 if (info->hdr->e_shoff >= info->len
2626 || (info->hdr->e_shnum * sizeof(Elf_Shdr) >
2627 info->len - info->hdr->e_shoff))
2628 return -ENOEXEC;
2629
2630 return 0;
2631 }
2632
2633 #define COPY_CHUNK_SIZE (16*PAGE_SIZE)
2634
2635 static int copy_chunked_from_user(void *dst, const void __user *usrc, unsigned long len)
2636 {
2637 do {
2638 unsigned long n = min(len, COPY_CHUNK_SIZE);
2639
2640 if (copy_from_user(dst, usrc, n) != 0)
2641 return -EFAULT;
2642 cond_resched();
2643 dst += n;
2644 usrc += n;
2645 len -= n;
2646 } while (len);
2647 return 0;
2648 }
2649
2650 /* Sets info->hdr and info->len. */
2651 static int copy_module_from_user(const void __user *umod, unsigned long len,
2652 struct load_info *info)
2653 {
2654 int err;
2655
2656 info->len = len;
2657 if (info->len < sizeof(*(info->hdr)))
2658 return -ENOEXEC;
2659
2660 err = security_kernel_module_from_file(NULL);
2661 if (err)
2662 return err;
2663
2664 /* Suck in entire file: we'll want most of it. */
2665 info->hdr = __vmalloc(info->len,
2666 GFP_KERNEL | __GFP_HIGHMEM | __GFP_NOWARN, PAGE_KERNEL);
2667 if (!info->hdr)
2668 return -ENOMEM;
2669
2670 if (copy_chunked_from_user(info->hdr, umod, info->len) != 0) {
2671 vfree(info->hdr);
2672 return -EFAULT;
2673 }
2674
2675 return 0;
2676 }
2677
2678 /* Sets info->hdr and info->len. */
2679 static int copy_module_from_fd(int fd, struct load_info *info)
2680 {
2681 struct fd f = fdget(fd);
2682 int err;
2683 struct kstat stat;
2684 loff_t pos;
2685 ssize_t bytes = 0;
2686
2687 if (!f.file)
2688 return -ENOEXEC;
2689
2690 err = security_kernel_module_from_file(f.file);
2691 if (err)
2692 goto out;
2693
2694 err = vfs_getattr(&f.file->f_path, &stat);
2695 if (err)
2696 goto out;
2697
2698 if (stat.size > INT_MAX) {
2699 err = -EFBIG;
2700 goto out;
2701 }
2702
2703 /* Don't hand 0 to vmalloc, it whines. */
2704 if (stat.size == 0) {
2705 err = -EINVAL;
2706 goto out;
2707 }
2708
2709 info->hdr = vmalloc(stat.size);
2710 if (!info->hdr) {
2711 err = -ENOMEM;
2712 goto out;
2713 }
2714
2715 pos = 0;
2716 while (pos < stat.size) {
2717 bytes = kernel_read(f.file, pos, (char *)(info->hdr) + pos,
2718 stat.size - pos);
2719 if (bytes < 0) {
2720 vfree(info->hdr);
2721 err = bytes;
2722 goto out;
2723 }
2724 if (bytes == 0)
2725 break;
2726 pos += bytes;
2727 }
2728 info->len = pos;
2729
2730 out:
2731 fdput(f);
2732 return err;
2733 }
2734
2735 static void free_copy(struct load_info *info)
2736 {
2737 vfree(info->hdr);
2738 }
2739
2740 static int rewrite_section_headers(struct load_info *info, int flags)
2741 {
2742 unsigned int i;
2743
2744 /* This should always be true, but let's be sure. */
2745 info->sechdrs[0].sh_addr = 0;
2746
2747 for (i = 1; i < info->hdr->e_shnum; i++) {
2748 Elf_Shdr *shdr = &info->sechdrs[i];
2749 if (shdr->sh_type != SHT_NOBITS
2750 && info->len < shdr->sh_offset + shdr->sh_size) {
2751 pr_err("Module len %lu truncated\n", info->len);
2752 return -ENOEXEC;
2753 }
2754
2755 /* Mark all sections sh_addr with their address in the
2756 temporary image. */
2757 shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
2758
2759 #ifndef CONFIG_MODULE_UNLOAD
2760 /* Don't load .exit sections */
2761 if (strstarts(info->secstrings+shdr->sh_name, ".exit"))
2762 shdr->sh_flags &= ~(unsigned long)SHF_ALLOC;
2763 #endif
2764 }
2765
2766 /* Track but don't keep modinfo and version sections. */
2767 if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
2768 info->index.vers = 0; /* Pretend no __versions section! */
2769 else
2770 info->index.vers = find_sec(info, "__versions");
2771 info->index.info = find_sec(info, ".modinfo");
2772 info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
2773 info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
2774 return 0;
2775 }
2776
2777 /*
2778 * Set up our basic convenience variables (pointers to section headers,
2779 * search for module section index etc), and do some basic section
2780 * verification.
2781 *
2782 * Return the temporary module pointer (we'll replace it with the final
2783 * one when we move the module sections around).
2784 */
2785 static struct module *setup_load_info(struct load_info *info, int flags)
2786 {
2787 unsigned int i;
2788 int err;
2789 struct module *mod;
2790
2791 /* Set up the convenience variables */
2792 info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
2793 info->secstrings = (void *)info->hdr
2794 + info->sechdrs[info->hdr->e_shstrndx].sh_offset;
2795
2796 err = rewrite_section_headers(info, flags);
2797 if (err)
2798 return ERR_PTR(err);
2799
2800 /* Find internal symbols and strings. */
2801 for (i = 1; i < info->hdr->e_shnum; i++) {
2802 if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
2803 info->index.sym = i;
2804 info->index.str = info->sechdrs[i].sh_link;
2805 info->strtab = (char *)info->hdr
2806 + info->sechdrs[info->index.str].sh_offset;
2807 break;
2808 }
2809 }
2810
2811 info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
2812 if (!info->index.mod) {
2813 pr_warn("No module found in object\n");
2814 return ERR_PTR(-ENOEXEC);
2815 }
2816 /* This is temporary: point mod into copy of data. */
2817 mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2818
2819 if (info->index.sym == 0) {
2820 pr_warn("%s: module has no symbols (stripped?)\n", mod->name);
2821 return ERR_PTR(-ENOEXEC);
2822 }
2823
2824 info->index.pcpu = find_pcpusec(info);
2825
2826 /* Check module struct version now, before we try to use module. */
2827 if (!check_modstruct_version(info->sechdrs, info->index.vers, mod))
2828 return ERR_PTR(-ENOEXEC);
2829
2830 return mod;
2831 }
2832
2833 static int check_modinfo(struct module *mod, struct load_info *info, int flags)
2834 {
2835 const char *modmagic = get_modinfo(info, "vermagic");
2836 int err;
2837
2838 if (flags & MODULE_INIT_IGNORE_VERMAGIC)
2839 modmagic = NULL;
2840
2841 /* This is allowed: modprobe --force will invalidate it. */
2842 if (!modmagic) {
2843 err = try_to_force_load(mod, "bad vermagic");
2844 if (err)
2845 return err;
2846 } else if (!same_magic(modmagic, vermagic, info->index.vers)) {
2847 pr_err("%s: version magic '%s' should be '%s'\n",
2848 mod->name, modmagic, vermagic);
2849 return -ENOEXEC;
2850 }
2851
2852 if (!get_modinfo(info, "intree"))
2853 add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
2854
2855 if (get_modinfo(info, "staging")) {
2856 add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
2857 pr_warn("%s: module is from the staging directory, the quality "
2858 "is unknown, you have been warned.\n", mod->name);
2859 }
2860
2861 /* Set up license info based on the info section */
2862 set_license(mod, get_modinfo(info, "license"));
2863
2864 return 0;
2865 }
2866
2867 static int find_module_sections(struct module *mod, struct load_info *info)
2868 {
2869 mod->kp = section_objs(info, "__param",
2870 sizeof(*mod->kp), &mod->num_kp);
2871 mod->syms = section_objs(info, "__ksymtab",
2872 sizeof(*mod->syms), &mod->num_syms);
2873 mod->crcs = section_addr(info, "__kcrctab");
2874 mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
2875 sizeof(*mod->gpl_syms),
2876 &mod->num_gpl_syms);
2877 mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
2878 mod->gpl_future_syms = section_objs(info,
2879 "__ksymtab_gpl_future",
2880 sizeof(*mod->gpl_future_syms),
2881 &mod->num_gpl_future_syms);
2882 mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future");
2883
2884 #ifdef CONFIG_UNUSED_SYMBOLS
2885 mod->unused_syms = section_objs(info, "__ksymtab_unused",
2886 sizeof(*mod->unused_syms),
2887 &mod->num_unused_syms);
2888 mod->unused_crcs = section_addr(info, "__kcrctab_unused");
2889 mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl",
2890 sizeof(*mod->unused_gpl_syms),
2891 &mod->num_unused_gpl_syms);
2892 mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl");
2893 #endif
2894 #ifdef CONFIG_CONSTRUCTORS
2895 mod->ctors = section_objs(info, ".ctors",
2896 sizeof(*mod->ctors), &mod->num_ctors);
2897 if (!mod->ctors)
2898 mod->ctors = section_objs(info, ".init_array",
2899 sizeof(*mod->ctors), &mod->num_ctors);
2900 else if (find_sec(info, ".init_array")) {
2901 /*
2902 * This shouldn't happen with same compiler and binutils
2903 * building all parts of the module.
2904 */
2905 pr_warn("%s: has both .ctors and .init_array.\n",
2906 mod->name);
2907 return -EINVAL;
2908 }
2909 #endif
2910
2911 #ifdef CONFIG_TRACEPOINTS
2912 mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
2913 sizeof(*mod->tracepoints_ptrs),
2914 &mod->num_tracepoints);
2915 #endif
2916 #ifdef HAVE_JUMP_LABEL
2917 mod->jump_entries = section_objs(info, "__jump_table",
2918 sizeof(*mod->jump_entries),
2919 &mod->num_jump_entries);
2920 #endif
2921 #ifdef CONFIG_EVENT_TRACING
2922 mod->trace_events = section_objs(info, "_ftrace_events",
2923 sizeof(*mod->trace_events),
2924 &mod->num_trace_events);
2925 mod->trace_enums = section_objs(info, "_ftrace_enum_map",
2926 sizeof(*mod->trace_enums),
2927 &mod->num_trace_enums);
2928 #endif
2929 #ifdef CONFIG_TRACING
2930 mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
2931 sizeof(*mod->trace_bprintk_fmt_start),
2932 &mod->num_trace_bprintk_fmt);
2933 #endif
2934 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
2935 /* sechdrs[0].sh_size is always zero */
2936 mod->ftrace_callsites = section_objs(info, "__mcount_loc",
2937 sizeof(*mod->ftrace_callsites),
2938 &mod->num_ftrace_callsites);
2939 #endif
2940
2941 mod->extable = section_objs(info, "__ex_table",
2942 sizeof(*mod->extable), &mod->num_exentries);
2943
2944 if (section_addr(info, "__obsparm"))
2945 pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
2946
2947 info->debug = section_objs(info, "__verbose",
2948 sizeof(*info->debug), &info->num_debug);
2949
2950 return 0;
2951 }
2952
2953 static int move_module(struct module *mod, struct load_info *info)
2954 {
2955 int i;
2956 void *ptr;
2957
2958 /* Do the allocs. */
2959 ptr = module_alloc(mod->core_size);
2960 /*
2961 * The pointer to this block is stored in the module structure
2962 * which is inside the block. Just mark it as not being a
2963 * leak.
2964 */
2965 kmemleak_not_leak(ptr);
2966 if (!ptr)
2967 return -ENOMEM;
2968
2969 memset(ptr, 0, mod->core_size);
2970 mod->module_core = ptr;
2971
2972 if (mod->init_size) {
2973 ptr = module_alloc(mod->init_size);
2974 /*
2975 * The pointer to this block is stored in the module structure
2976 * which is inside the block. This block doesn't need to be
2977 * scanned as it contains data and code that will be freed
2978 * after the module is initialized.
2979 */
2980 kmemleak_ignore(ptr);
2981 if (!ptr) {
2982 module_memfree(mod->module_core);
2983 return -ENOMEM;
2984 }
2985 memset(ptr, 0, mod->init_size);
2986 mod->module_init = ptr;
2987 } else
2988 mod->module_init = NULL;
2989
2990 /* Transfer each section which specifies SHF_ALLOC */
2991 pr_debug("final section addresses:\n");
2992 for (i = 0; i < info->hdr->e_shnum; i++) {
2993 void *dest;
2994 Elf_Shdr *shdr = &info->sechdrs[i];
2995
2996 if (!(shdr->sh_flags & SHF_ALLOC))
2997 continue;
2998
2999 if (shdr->sh_entsize & INIT_OFFSET_MASK)
3000 dest = mod->module_init
3001 + (shdr->sh_entsize & ~INIT_OFFSET_MASK);
3002 else
3003 dest = mod->module_core + shdr->sh_entsize;
3004
3005 if (shdr->sh_type != SHT_NOBITS)
3006 memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
3007 /* Update sh_addr to point to copy in image. */
3008 shdr->sh_addr = (unsigned long)dest;
3009 pr_debug("\t0x%lx %s\n",
3010 (long)shdr->sh_addr, info->secstrings + shdr->sh_name);
3011 }
3012
3013 return 0;
3014 }
3015
3016 static int check_module_license_and_versions(struct module *mod)
3017 {
3018 /*
3019 * ndiswrapper is under GPL by itself, but loads proprietary modules.
3020 * Don't use add_taint_module(), as it would prevent ndiswrapper from
3021 * using GPL-only symbols it needs.
3022 */
3023 if (strcmp(mod->name, "ndiswrapper") == 0)
3024 add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
3025
3026 /* driverloader was caught wrongly pretending to be under GPL */
3027 if (strcmp(mod->name, "driverloader") == 0)
3028 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3029 LOCKDEP_NOW_UNRELIABLE);
3030
3031 /* lve claims to be GPL but upstream won't provide source */
3032 if (strcmp(mod->name, "lve") == 0)
3033 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3034 LOCKDEP_NOW_UNRELIABLE);
3035
3036 #ifdef CONFIG_MODVERSIONS
3037 if ((mod->num_syms && !mod->crcs)
3038 || (mod->num_gpl_syms && !mod->gpl_crcs)
3039 || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
3040 #ifdef CONFIG_UNUSED_SYMBOLS
3041 || (mod->num_unused_syms && !mod->unused_crcs)
3042 || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
3043 #endif
3044 ) {
3045 return try_to_force_load(mod,
3046 "no versions for exported symbols");
3047 }
3048 #endif
3049 return 0;
3050 }
3051
3052 static void flush_module_icache(const struct module *mod)
3053 {
3054 mm_segment_t old_fs;
3055
3056 /* flush the icache in correct context */
3057 old_fs = get_fs();
3058 set_fs(KERNEL_DS);
3059
3060 /*
3061 * Flush the instruction cache, since we've played with text.
3062 * Do it before processing of module parameters, so the module
3063 * can provide parameter accessor functions of its own.
3064 */
3065 if (mod->module_init)
3066 flush_icache_range((unsigned long)mod->module_init,
3067 (unsigned long)mod->module_init
3068 + mod->init_size);
3069 flush_icache_range((unsigned long)mod->module_core,
3070 (unsigned long)mod->module_core + mod->core_size);
3071
3072 set_fs(old_fs);
3073 }
3074
3075 int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
3076 Elf_Shdr *sechdrs,
3077 char *secstrings,
3078 struct module *mod)
3079 {
3080 return 0;
3081 }
3082
3083 static struct module *layout_and_allocate(struct load_info *info, int flags)
3084 {
3085 /* Module within temporary copy. */
3086 struct module *mod;
3087 int err;
3088
3089 mod = setup_load_info(info, flags);
3090 if (IS_ERR(mod))
3091 return mod;
3092
3093 err = check_modinfo(mod, info, flags);
3094 if (err)
3095 return ERR_PTR(err);
3096
3097 /* Allow arches to frob section contents and sizes. */
3098 err = module_frob_arch_sections(info->hdr, info->sechdrs,
3099 info->secstrings, mod);
3100 if (err < 0)
3101 return ERR_PTR(err);
3102
3103 /* We will do a special allocation for per-cpu sections later. */
3104 info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC;
3105
3106 /* Determine total sizes, and put offsets in sh_entsize. For now
3107 this is done generically; there doesn't appear to be any
3108 special cases for the architectures. */
3109 layout_sections(mod, info);
3110 layout_symtab(mod, info);
3111
3112 /* Allocate and move to the final place */
3113 err = move_module(mod, info);
3114 if (err)
3115 return ERR_PTR(err);
3116
3117 /* Module has been copied to its final place now: return it. */
3118 mod = (void *)info->sechdrs[info->index.mod].sh_addr;
3119 kmemleak_load_module(mod, info);
3120 return mod;
3121 }
3122
3123 /* mod is no longer valid after this! */
3124 static void module_deallocate(struct module *mod, struct load_info *info)
3125 {
3126 percpu_modfree(mod);
3127 module_arch_freeing_init(mod);
3128 module_memfree(mod->module_init);
3129 module_memfree(mod->module_core);
3130 }
3131
3132 int __weak module_finalize(const Elf_Ehdr *hdr,
3133 const Elf_Shdr *sechdrs,
3134 struct module *me)
3135 {
3136 return 0;
3137 }
3138
3139 static int post_relocation(struct module *mod, const struct load_info *info)
3140 {
3141 /* Sort exception table now relocations are done. */
3142 sort_extable(mod->extable, mod->extable + mod->num_exentries);
3143
3144 /* Copy relocated percpu area over. */
3145 percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
3146 info->sechdrs[info->index.pcpu].sh_size);
3147
3148 /* Setup kallsyms-specific fields. */
3149 add_kallsyms(mod, info);
3150
3151 /* Arch-specific module finalizing. */
3152 return module_finalize(info->hdr, info->sechdrs, mod);
3153 }
3154
3155 /* Is this module of this name done loading? No locks held. */
3156 static bool finished_loading(const char *name)
3157 {
3158 struct module *mod;
3159 bool ret;
3160
3161 /*
3162 * The module_mutex should not be a heavily contended lock;
3163 * if we get the occasional sleep here, we'll go an extra iteration
3164 * in the wait_event_interruptible(), which is harmless.
3165 */
3166 sched_annotate_sleep();
3167 mutex_lock(&module_mutex);
3168 mod = find_module_all(name, strlen(name), true);
3169 ret = !mod || mod->state == MODULE_STATE_LIVE
3170 || mod->state == MODULE_STATE_GOING;
3171 mutex_unlock(&module_mutex);
3172
3173 return ret;
3174 }
3175
3176 /* Call module constructors. */
3177 static void do_mod_ctors(struct module *mod)
3178 {
3179 #ifdef CONFIG_CONSTRUCTORS
3180 unsigned long i;
3181
3182 for (i = 0; i < mod->num_ctors; i++)
3183 mod->ctors[i]();
3184 #endif
3185 }
3186
3187 /* For freeing module_init on success, in case kallsyms traversing */
3188 struct mod_initfree {
3189 struct rcu_head rcu;
3190 void *module_init;
3191 };
3192
3193 static void do_free_init(struct rcu_head *head)
3194 {
3195 struct mod_initfree *m = container_of(head, struct mod_initfree, rcu);
3196 module_memfree(m->module_init);
3197 kfree(m);
3198 }
3199
3200 /*
3201 * This is where the real work happens.
3202 *
3203 * Keep it uninlined to provide a reliable breakpoint target, e.g. for the gdb
3204 * helper command 'lx-symbols'.
3205 */
3206 static noinline int do_init_module(struct module *mod)
3207 {
3208 int ret = 0;
3209 struct mod_initfree *freeinit;
3210
3211 freeinit = kmalloc(sizeof(*freeinit), GFP_KERNEL);
3212 if (!freeinit) {
3213 ret = -ENOMEM;
3214 goto fail;
3215 }
3216 freeinit->module_init = mod->module_init;
3217
3218 /*
3219 * We want to find out whether @mod uses async during init. Clear
3220 * PF_USED_ASYNC. async_schedule*() will set it.
3221 */
3222 current->flags &= ~PF_USED_ASYNC;
3223
3224 do_mod_ctors(mod);
3225 /* Start the module */
3226 if (mod->init != NULL)
3227 ret = do_one_initcall(mod->init);
3228 if (ret < 0) {
3229 goto fail_free_freeinit;
3230 }
3231 if (ret > 0) {
3232 pr_warn("%s: '%s'->init suspiciously returned %d, it should "
3233 "follow 0/-E convention\n"
3234 "%s: loading module anyway...\n",
3235 __func__, mod->name, ret, __func__);
3236 dump_stack();
3237 }
3238
3239 /* Now it's a first class citizen! */
3240 mod->state = MODULE_STATE_LIVE;
3241 blocking_notifier_call_chain(&module_notify_list,
3242 MODULE_STATE_LIVE, mod);
3243
3244 /*
3245 * We need to finish all async code before the module init sequence
3246 * is done. This has potential to deadlock. For example, a newly
3247 * detected block device can trigger request_module() of the
3248 * default iosched from async probing task. Once userland helper
3249 * reaches here, async_synchronize_full() will wait on the async
3250 * task waiting on request_module() and deadlock.
3251 *
3252 * This deadlock is avoided by perfomring async_synchronize_full()
3253 * iff module init queued any async jobs. This isn't a full
3254 * solution as it will deadlock the same if module loading from
3255 * async jobs nests more than once; however, due to the various
3256 * constraints, this hack seems to be the best option for now.
3257 * Please refer to the following thread for details.
3258 *
3259 * http://thread.gmane.org/gmane.linux.kernel/1420814
3260 */
3261 if (!mod->async_probe_requested && (current->flags & PF_USED_ASYNC))
3262 async_synchronize_full();
3263
3264 mutex_lock(&module_mutex);
3265 /* Drop initial reference. */
3266 module_put(mod);
3267 trim_init_extable(mod);
3268 #ifdef CONFIG_KALLSYMS
3269 mod->num_symtab = mod->core_num_syms;
3270 mod->symtab = mod->core_symtab;
3271 mod->strtab = mod->core_strtab;
3272 #endif
3273 mod_tree_remove_init(mod);
3274 unset_module_init_ro_nx(mod);
3275 module_arch_freeing_init(mod);
3276 mod->module_init = NULL;
3277 mod->init_size = 0;
3278 mod->init_ro_size = 0;
3279 mod->init_text_size = 0;
3280 /*
3281 * We want to free module_init, but be aware that kallsyms may be
3282 * walking this with preempt disabled. In all the failure paths, we
3283 * call synchronize_sched(), but we don't want to slow down the success
3284 * path, so use actual RCU here.
3285 */
3286 call_rcu_sched(&freeinit->rcu, do_free_init);
3287 mutex_unlock(&module_mutex);
3288 wake_up_all(&module_wq);
3289
3290 return 0;
3291
3292 fail_free_freeinit:
3293 kfree(freeinit);
3294 fail:
3295 /* Try to protect us from buggy refcounters. */
3296 mod->state = MODULE_STATE_GOING;
3297 synchronize_sched();
3298 module_put(mod);
3299 blocking_notifier_call_chain(&module_notify_list,
3300 MODULE_STATE_GOING, mod);
3301 free_module(mod);
3302 wake_up_all(&module_wq);
3303 return ret;
3304 }
3305
3306 static int may_init_module(void)
3307 {
3308 if (!capable(CAP_SYS_MODULE) || modules_disabled)
3309 return -EPERM;
3310
3311 return 0;
3312 }
3313
3314 /*
3315 * We try to place it in the list now to make sure it's unique before
3316 * we dedicate too many resources. In particular, temporary percpu
3317 * memory exhaustion.
3318 */
3319 static int add_unformed_module(struct module *mod)
3320 {
3321 int err;
3322 struct module *old;
3323
3324 mod->state = MODULE_STATE_UNFORMED;
3325
3326 again:
3327 mutex_lock(&module_mutex);
3328 old = find_module_all(mod->name, strlen(mod->name), true);
3329 if (old != NULL) {
3330 if (old->state == MODULE_STATE_COMING
3331 || old->state == MODULE_STATE_UNFORMED) {
3332 /* Wait in case it fails to load. */
3333 mutex_unlock(&module_mutex);
3334 err = wait_event_interruptible(module_wq,
3335 finished_loading(mod->name));
3336 if (err)
3337 goto out_unlocked;
3338 goto again;
3339 }
3340 err = -EEXIST;
3341 goto out;
3342 }
3343 mod_update_bounds(mod);
3344 list_add_rcu(&mod->list, &modules);
3345 mod_tree_insert(mod);
3346 err = 0;
3347
3348 out:
3349 mutex_unlock(&module_mutex);
3350 out_unlocked:
3351 return err;
3352 }
3353
3354 static int complete_formation(struct module *mod, struct load_info *info)
3355 {
3356 int err;
3357
3358 mutex_lock(&module_mutex);
3359
3360 /* Find duplicate symbols (must be called under lock). */
3361 err = verify_export_symbols(mod);
3362 if (err < 0)
3363 goto out;
3364
3365 /* This relies on module_mutex for list integrity. */
3366 module_bug_finalize(info->hdr, info->sechdrs, mod);
3367
3368 /* Set RO and NX regions for core */
3369 set_section_ro_nx(mod->module_core,
3370 mod->core_text_size,
3371 mod->core_ro_size,
3372 mod->core_size);
3373
3374 /* Set RO and NX regions for init */
3375 set_section_ro_nx(mod->module_init,
3376 mod->init_text_size,
3377 mod->init_ro_size,
3378 mod->init_size);
3379
3380 /* Mark state as coming so strong_try_module_get() ignores us,
3381 * but kallsyms etc. can see us. */
3382 mod->state = MODULE_STATE_COMING;
3383 mutex_unlock(&module_mutex);
3384
3385 blocking_notifier_call_chain(&module_notify_list,
3386 MODULE_STATE_COMING, mod);
3387 return 0;
3388
3389 out:
3390 mutex_unlock(&module_mutex);
3391 return err;
3392 }
3393
3394 static int unknown_module_param_cb(char *param, char *val, const char *modname,
3395 void *arg)
3396 {
3397 struct module *mod = arg;
3398 int ret;
3399
3400 if (strcmp(param, "async_probe") == 0) {
3401 mod->async_probe_requested = true;
3402 return 0;
3403 }
3404
3405 /* Check for magic 'dyndbg' arg */
3406 ret = ddebug_dyndbg_module_param_cb(param, val, modname);
3407 if (ret != 0)
3408 pr_warn("%s: unknown parameter '%s' ignored\n", modname, param);
3409 return 0;
3410 }
3411
3412 /* Allocate and load the module: note that size of section 0 is always
3413 zero, and we rely on this for optional sections. */
3414 static int load_module(struct load_info *info, const char __user *uargs,
3415 int flags)
3416 {
3417 struct module *mod;
3418 long err;
3419 char *after_dashes;
3420
3421 err = module_sig_check(info);
3422 if (err)
3423 goto free_copy;
3424
3425 err = elf_header_check(info);
3426 if (err)
3427 goto free_copy;
3428
3429 /* Figure out module layout, and allocate all the memory. */
3430 mod = layout_and_allocate(info, flags);
3431 if (IS_ERR(mod)) {
3432 err = PTR_ERR(mod);
3433 goto free_copy;
3434 }
3435
3436 /* Reserve our place in the list. */
3437 err = add_unformed_module(mod);
3438 if (err)
3439 goto free_module;
3440
3441 #ifdef CONFIG_MODULE_SIG
3442 mod->sig_ok = info->sig_ok;
3443 if (!mod->sig_ok) {
3444 pr_notice_once("%s: module verification failed: signature "
3445 "and/or required key missing - tainting "
3446 "kernel\n", mod->name);
3447 add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK);
3448 }
3449 #endif
3450
3451 /* To avoid stressing percpu allocator, do this once we're unique. */
3452 err = percpu_modalloc(mod, info);
3453 if (err)
3454 goto unlink_mod;
3455
3456 /* Now module is in final location, initialize linked lists, etc. */
3457 err = module_unload_init(mod);
3458 if (err)
3459 goto unlink_mod;
3460
3461 init_param_lock(mod);
3462
3463 /* Now we've got everything in the final locations, we can
3464 * find optional sections. */
3465 err = find_module_sections(mod, info);
3466 if (err)
3467 goto free_unload;
3468
3469 err = check_module_license_and_versions(mod);
3470 if (err)
3471 goto free_unload;
3472
3473 /* Set up MODINFO_ATTR fields */
3474 setup_modinfo(mod, info);
3475
3476 /* Fix up syms, so that st_value is a pointer to location. */
3477 err = simplify_symbols(mod, info);
3478 if (err < 0)
3479 goto free_modinfo;
3480
3481 err = apply_relocations(mod, info);
3482 if (err < 0)
3483 goto free_modinfo;
3484
3485 err = post_relocation(mod, info);
3486 if (err < 0)
3487 goto free_modinfo;
3488
3489 flush_module_icache(mod);
3490
3491 /* Now copy in args */
3492 mod->args = strndup_user(uargs, ~0UL >> 1);
3493 if (IS_ERR(mod->args)) {
3494 err = PTR_ERR(mod->args);
3495 goto free_arch_cleanup;
3496 }
3497
3498 dynamic_debug_setup(info->debug, info->num_debug);
3499
3500 /* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
3501 ftrace_module_init(mod);
3502
3503 /* Finally it's fully formed, ready to start executing. */
3504 err = complete_formation(mod, info);
3505 if (err)
3506 goto ddebug_cleanup;
3507
3508 /* Module is ready to execute: parsing args may do that. */
3509 after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
3510 -32768, 32767, NULL,
3511 unknown_module_param_cb);
3512 if (IS_ERR(after_dashes)) {
3513 err = PTR_ERR(after_dashes);
3514 goto bug_cleanup;
3515 } else if (after_dashes) {
3516 pr_warn("%s: parameters '%s' after `--' ignored\n",
3517 mod->name, after_dashes);
3518 }
3519
3520 /* Link in to syfs. */
3521 err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
3522 if (err < 0)
3523 goto bug_cleanup;
3524
3525 /* Get rid of temporary copy. */
3526 free_copy(info);
3527
3528 /* Done! */
3529 trace_module_load(mod);
3530
3531 return do_init_module(mod);
3532
3533 bug_cleanup:
3534 /* module_bug_cleanup needs module_mutex protection */
3535 mutex_lock(&module_mutex);
3536 module_bug_cleanup(mod);
3537 mutex_unlock(&module_mutex);
3538
3539 blocking_notifier_call_chain(&module_notify_list,
3540 MODULE_STATE_GOING, mod);
3541
3542 /* we can't deallocate the module until we clear memory protection */
3543 unset_module_init_ro_nx(mod);
3544 unset_module_core_ro_nx(mod);
3545
3546 ddebug_cleanup:
3547 dynamic_debug_remove(info->debug);
3548 synchronize_sched();
3549 kfree(mod->args);
3550 free_arch_cleanup:
3551 module_arch_cleanup(mod);
3552 free_modinfo:
3553 free_modinfo(mod);
3554 free_unload:
3555 module_unload_free(mod);
3556 unlink_mod:
3557 mutex_lock(&module_mutex);
3558 /* Unlink carefully: kallsyms could be walking list. */
3559 list_del_rcu(&mod->list);
3560 mod_tree_remove(mod);
3561 wake_up_all(&module_wq);
3562 /* Wait for RCU-sched synchronizing before releasing mod->list. */
3563 synchronize_sched();
3564 mutex_unlock(&module_mutex);
3565 free_module:
3566 /* Free lock-classes; relies on the preceding sync_rcu() */
3567 lockdep_free_key_range(mod->module_core, mod->core_size);
3568
3569 module_deallocate(mod, info);
3570 free_copy:
3571 free_copy(info);
3572 return err;
3573 }
3574
3575 SYSCALL_DEFINE3(init_module, void __user *, umod,
3576 unsigned long, len, const char __user *, uargs)
3577 {
3578 int err;
3579 struct load_info info = { };
3580
3581 err = may_init_module();
3582 if (err)
3583 return err;
3584
3585 pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
3586 umod, len, uargs);
3587
3588 err = copy_module_from_user(umod, len, &info);
3589 if (err)
3590 return err;
3591
3592 return load_module(&info, uargs, 0);
3593 }
3594
3595 SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
3596 {
3597 int err;
3598 struct load_info info = { };
3599
3600 err = may_init_module();
3601 if (err)
3602 return err;
3603
3604 pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags);
3605
3606 if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS
3607 |MODULE_INIT_IGNORE_VERMAGIC))
3608 return -EINVAL;
3609
3610 err = copy_module_from_fd(fd, &info);
3611 if (err)
3612 return err;
3613
3614 return load_module(&info, uargs, flags);
3615 }
3616
3617 static inline int within(unsigned long addr, void *start, unsigned long size)
3618 {
3619 return ((void *)addr >= start && (void *)addr < start + size);
3620 }
3621
3622 #ifdef CONFIG_KALLSYMS
3623 /*
3624 * This ignores the intensely annoying "mapping symbols" found
3625 * in ARM ELF files: $a, $t and $d.
3626 */
3627 static inline int is_arm_mapping_symbol(const char *str)
3628 {
3629 if (str[0] == '.' && str[1] == 'L')
3630 return true;
3631 return str[0] == '$' && strchr("axtd", str[1])
3632 && (str[2] == '\0' || str[2] == '.');
3633 }
3634
3635 static const char *get_ksymbol(struct module *mod,
3636 unsigned long addr,
3637 unsigned long *size,
3638 unsigned long *offset)
3639 {
3640 unsigned int i, best = 0;
3641 unsigned long nextval;
3642
3643 /* At worse, next value is at end of module */
3644 if (within_module_init(addr, mod))
3645 nextval = (unsigned long)mod->module_init+mod->init_text_size;
3646 else
3647 nextval = (unsigned long)mod->module_core+mod->core_text_size;
3648
3649 /* Scan for closest preceding symbol, and next symbol. (ELF
3650 starts real symbols at 1). */
3651 for (i = 1; i < mod->num_symtab; i++) {
3652 if (mod->symtab[i].st_shndx == SHN_UNDEF)
3653 continue;
3654
3655 /* We ignore unnamed symbols: they're uninformative
3656 * and inserted at a whim. */
3657 if (mod->symtab[i].st_value <= addr
3658 && mod->symtab[i].st_value > mod->symtab[best].st_value
3659 && *(mod->strtab + mod->symtab[i].st_name) != '\0'
3660 && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
3661 best = i;
3662 if (mod->symtab[i].st_value > addr
3663 && mod->symtab[i].st_value < nextval
3664 && *(mod->strtab + mod->symtab[i].st_name) != '\0'
3665 && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
3666 nextval = mod->symtab[i].st_value;
3667 }
3668
3669 if (!best)
3670 return NULL;
3671
3672 if (size)
3673 *size = nextval - mod->symtab[best].st_value;
3674 if (offset)
3675 *offset = addr - mod->symtab[best].st_value;
3676 return mod->strtab + mod->symtab[best].st_name;
3677 }
3678
3679 /* For kallsyms to ask for address resolution. NULL means not found. Careful
3680 * not to lock to avoid deadlock on oopses, simply disable preemption. */
3681 const char *module_address_lookup(unsigned long addr,
3682 unsigned long *size,
3683 unsigned long *offset,
3684 char **modname,
3685 char *namebuf)
3686 {
3687 const char *ret = NULL;
3688 struct module *mod;
3689
3690 preempt_disable();
3691 mod = __module_address(addr);
3692 if (mod) {
3693 if (modname)
3694 *modname = mod->name;
3695 ret = get_ksymbol(mod, addr, size, offset);
3696 }
3697 /* Make a copy in here where it's safe */
3698 if (ret) {
3699 strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
3700 ret = namebuf;
3701 }
3702 preempt_enable();
3703
3704 return ret;
3705 }
3706
3707 int lookup_module_symbol_name(unsigned long addr, char *symname)
3708 {
3709 struct module *mod;
3710
3711 preempt_disable();
3712 list_for_each_entry_rcu(mod, &modules, list) {
3713 if (mod->state == MODULE_STATE_UNFORMED)
3714 continue;
3715 if (within_module(addr, mod)) {
3716 const char *sym;
3717
3718 sym = get_ksymbol(mod, addr, NULL, NULL);
3719 if (!sym)
3720 goto out;
3721 strlcpy(symname, sym, KSYM_NAME_LEN);
3722 preempt_enable();
3723 return 0;
3724 }
3725 }
3726 out:
3727 preempt_enable();
3728 return -ERANGE;
3729 }
3730
3731 int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
3732 unsigned long *offset, char *modname, char *name)
3733 {
3734 struct module *mod;
3735
3736 preempt_disable();
3737 list_for_each_entry_rcu(mod, &modules, list) {
3738 if (mod->state == MODULE_STATE_UNFORMED)
3739 continue;
3740 if (within_module(addr, mod)) {
3741 const char *sym;
3742
3743 sym = get_ksymbol(mod, addr, size, offset);
3744 if (!sym)
3745 goto out;
3746 if (modname)
3747 strlcpy(modname, mod->name, MODULE_NAME_LEN);
3748 if (name)
3749 strlcpy(name, sym, KSYM_NAME_LEN);
3750 preempt_enable();
3751 return 0;
3752 }
3753 }
3754 out:
3755 preempt_enable();
3756 return -ERANGE;
3757 }
3758
3759 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
3760 char *name, char *module_name, int *exported)
3761 {
3762 struct module *mod;
3763
3764 preempt_disable();
3765 list_for_each_entry_rcu(mod, &modules, list) {
3766 if (mod->state == MODULE_STATE_UNFORMED)
3767 continue;
3768 if (symnum < mod->num_symtab) {
3769 *value = mod->symtab[symnum].st_value;
3770 *type = mod->symtab[symnum].st_info;
3771 strlcpy(name, mod->strtab + mod->symtab[symnum].st_name,
3772 KSYM_NAME_LEN);
3773 strlcpy(module_name, mod->name, MODULE_NAME_LEN);
3774 *exported = is_exported(name, *value, mod);
3775 preempt_enable();
3776 return 0;
3777 }
3778 symnum -= mod->num_symtab;
3779 }
3780 preempt_enable();
3781 return -ERANGE;
3782 }
3783
3784 static unsigned long mod_find_symname(struct module *mod, const char *name)
3785 {
3786 unsigned int i;
3787
3788 for (i = 0; i < mod->num_symtab; i++)
3789 if (strcmp(name, mod->strtab+mod->symtab[i].st_name) == 0 &&
3790 mod->symtab[i].st_info != 'U')
3791 return mod->symtab[i].st_value;
3792 return 0;
3793 }
3794
3795 /* Look for this name: can be of form module:name. */
3796 unsigned long module_kallsyms_lookup_name(const char *name)
3797 {
3798 struct module *mod;
3799 char *colon;
3800 unsigned long ret = 0;
3801
3802 /* Don't lock: we're in enough trouble already. */
3803 preempt_disable();
3804 if ((colon = strchr(name, ':')) != NULL) {
3805 if ((mod = find_module_all(name, colon - name, false)) != NULL)
3806 ret = mod_find_symname(mod, colon+1);
3807 } else {
3808 list_for_each_entry_rcu(mod, &modules, list) {
3809 if (mod->state == MODULE_STATE_UNFORMED)
3810 continue;
3811 if ((ret = mod_find_symname(mod, name)) != 0)
3812 break;
3813 }
3814 }
3815 preempt_enable();
3816 return ret;
3817 }
3818
3819 int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
3820 struct module *, unsigned long),
3821 void *data)
3822 {
3823 struct module *mod;
3824 unsigned int i;
3825 int ret;
3826
3827 module_assert_mutex();
3828
3829 list_for_each_entry(mod, &modules, list) {
3830 if (mod->state == MODULE_STATE_UNFORMED)
3831 continue;
3832 for (i = 0; i < mod->num_symtab; i++) {
3833 ret = fn(data, mod->strtab + mod->symtab[i].st_name,
3834 mod, mod->symtab[i].st_value);
3835 if (ret != 0)
3836 return ret;
3837 }
3838 }
3839 return 0;
3840 }
3841 #endif /* CONFIG_KALLSYMS */
3842
3843 static char *module_flags(struct module *mod, char *buf)
3844 {
3845 int bx = 0;
3846
3847 BUG_ON(mod->state == MODULE_STATE_UNFORMED);
3848 if (mod->taints ||
3849 mod->state == MODULE_STATE_GOING ||
3850 mod->state == MODULE_STATE_COMING) {
3851 buf[bx++] = '(';
3852 bx += module_flags_taint(mod, buf + bx);
3853 /* Show a - for module-is-being-unloaded */
3854 if (mod->state == MODULE_STATE_GOING)
3855 buf[bx++] = '-';
3856 /* Show a + for module-is-being-loaded */
3857 if (mod->state == MODULE_STATE_COMING)
3858 buf[bx++] = '+';
3859 buf[bx++] = ')';
3860 }
3861 buf[bx] = '\0';
3862
3863 return buf;
3864 }
3865
3866 #ifdef CONFIG_PROC_FS
3867 /* Called by the /proc file system to return a list of modules. */
3868 static void *m_start(struct seq_file *m, loff_t *pos)
3869 {
3870 mutex_lock(&module_mutex);
3871 return seq_list_start(&modules, *pos);
3872 }
3873
3874 static void *m_next(struct seq_file *m, void *p, loff_t *pos)
3875 {
3876 return seq_list_next(p, &modules, pos);
3877 }
3878
3879 static void m_stop(struct seq_file *m, void *p)
3880 {
3881 mutex_unlock(&module_mutex);
3882 }
3883
3884 static int m_show(struct seq_file *m, void *p)
3885 {
3886 struct module *mod = list_entry(p, struct module, list);
3887 char buf[8];
3888
3889 /* We always ignore unformed modules. */
3890 if (mod->state == MODULE_STATE_UNFORMED)
3891 return 0;
3892
3893 seq_printf(m, "%s %u",
3894 mod->name, mod->init_size + mod->core_size);
3895 print_unload_info(m, mod);
3896
3897 /* Informative for users. */
3898 seq_printf(m, " %s",
3899 mod->state == MODULE_STATE_GOING ? "Unloading" :
3900 mod->state == MODULE_STATE_COMING ? "Loading" :
3901 "Live");
3902 /* Used by oprofile and other similar tools. */
3903 seq_printf(m, " 0x%pK", mod->module_core);
3904
3905 /* Taints info */
3906 if (mod->taints)
3907 seq_printf(m, " %s", module_flags(mod, buf));
3908
3909 seq_puts(m, "\n");
3910 return 0;
3911 }
3912
3913 /* Format: modulename size refcount deps address
3914
3915 Where refcount is a number or -, and deps is a comma-separated list
3916 of depends or -.
3917 */
3918 static const struct seq_operations modules_op = {
3919 .start = m_start,
3920 .next = m_next,
3921 .stop = m_stop,
3922 .show = m_show
3923 };
3924
3925 static int modules_open(struct inode *inode, struct file *file)
3926 {
3927 return seq_open(file, &modules_op);
3928 }
3929
3930 static const struct file_operations proc_modules_operations = {
3931 .open = modules_open,
3932 .read = seq_read,
3933 .llseek = seq_lseek,
3934 .release = seq_release,
3935 };
3936
3937 static int __init proc_modules_init(void)
3938 {
3939 proc_create("modules", 0, NULL, &proc_modules_operations);
3940 return 0;
3941 }
3942 module_init(proc_modules_init);
3943 #endif
3944
3945 /* Given an address, look for it in the module exception tables. */
3946 const struct exception_table_entry *search_module_extables(unsigned long addr)
3947 {
3948 const struct exception_table_entry *e = NULL;
3949 struct module *mod;
3950
3951 preempt_disable();
3952 list_for_each_entry_rcu(mod, &modules, list) {
3953 if (mod->state == MODULE_STATE_UNFORMED)
3954 continue;
3955 if (mod->num_exentries == 0)
3956 continue;
3957
3958 e = search_extable(mod->extable,
3959 mod->extable + mod->num_exentries - 1,
3960 addr);
3961 if (e)
3962 break;
3963 }
3964 preempt_enable();
3965
3966 /* Now, if we found one, we are running inside it now, hence
3967 we cannot unload the module, hence no refcnt needed. */
3968 return e;
3969 }
3970
3971 /*
3972 * is_module_address - is this address inside a module?
3973 * @addr: the address to check.
3974 *
3975 * See is_module_text_address() if you simply want to see if the address
3976 * is code (not data).
3977 */
3978 bool is_module_address(unsigned long addr)
3979 {
3980 bool ret;
3981
3982 preempt_disable();
3983 ret = __module_address(addr) != NULL;
3984 preempt_enable();
3985
3986 return ret;
3987 }
3988
3989 /*
3990 * __module_address - get the module which contains an address.
3991 * @addr: the address.
3992 *
3993 * Must be called with preempt disabled or module mutex held so that
3994 * module doesn't get freed during this.
3995 */
3996 struct module *__module_address(unsigned long addr)
3997 {
3998 struct module *mod;
3999
4000 if (addr < module_addr_min || addr > module_addr_max)
4001 return NULL;
4002
4003 module_assert_mutex_or_preempt();
4004
4005 mod = mod_find(addr);
4006 if (mod) {
4007 BUG_ON(!within_module(addr, mod));
4008 if (mod->state == MODULE_STATE_UNFORMED)
4009 mod = NULL;
4010 }
4011 return mod;
4012 }
4013 EXPORT_SYMBOL_GPL(__module_address);
4014
4015 /*
4016 * is_module_text_address - is this address inside module code?
4017 * @addr: the address to check.
4018 *
4019 * See is_module_address() if you simply want to see if the address is
4020 * anywhere in a module. See kernel_text_address() for testing if an
4021 * address corresponds to kernel or module code.
4022 */
4023 bool is_module_text_address(unsigned long addr)
4024 {
4025 bool ret;
4026
4027 preempt_disable();
4028 ret = __module_text_address(addr) != NULL;
4029 preempt_enable();
4030
4031 return ret;
4032 }
4033
4034 /*
4035 * __module_text_address - get the module whose code contains an address.
4036 * @addr: the address.
4037 *
4038 * Must be called with preempt disabled or module mutex held so that
4039 * module doesn't get freed during this.
4040 */
4041 struct module *__module_text_address(unsigned long addr)
4042 {
4043 struct module *mod = __module_address(addr);
4044 if (mod) {
4045 /* Make sure it's within the text section. */
4046 if (!within(addr, mod->module_init, mod->init_text_size)
4047 && !within(addr, mod->module_core, mod->core_text_size))
4048 mod = NULL;
4049 }
4050 return mod;
4051 }
4052 EXPORT_SYMBOL_GPL(__module_text_address);
4053
4054 /* Don't grab lock, we're oopsing. */
4055 void print_modules(void)
4056 {
4057 struct module *mod;
4058 char buf[8];
4059
4060 printk(KERN_DEFAULT "Modules linked in:");
4061 /* Most callers should already have preempt disabled, but make sure */
4062 preempt_disable();
4063 list_for_each_entry_rcu(mod, &modules, list) {
4064 if (mod->state == MODULE_STATE_UNFORMED)
4065 continue;
4066 pr_cont(" %s%s", mod->name, module_flags(mod, buf));
4067 }
4068 preempt_enable();
4069 if (last_unloaded_module[0])
4070 pr_cont(" [last unloaded: %s]", last_unloaded_module);
4071 pr_cont("\n");
4072 }
4073
4074 #ifdef CONFIG_MODVERSIONS
4075 /* Generate the signature for all relevant module structures here.
4076 * If these change, we don't want to try to parse the module. */
4077 void module_layout(struct module *mod,
4078 struct modversion_info *ver,
4079 struct kernel_param *kp,
4080 struct kernel_symbol *ks,
4081 struct tracepoint * const *tp)
4082 {
4083 }
4084 EXPORT_SYMBOL(module_layout);
4085 #endif