1/*
2 Copyright (C) 2002 Richard Henderson
3 Copyright (C) 2001 Rusty Russell, 2002, 2010 Rusty Russell IBM.
4
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 2 of the License, or
8 (at your option) any later version.
9
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
14
15 You should have received a copy of the GNU General Public License
16 along with this program; if not, write to the Free Software
17 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18*/
19#include <linux/export.h>
20#include <linux/extable.h>
21#include <linux/moduleloader.h>
22#include <linux/trace_events.h>
23#include <linux/init.h>
24#include <linux/kallsyms.h>
25#include <linux/file.h>
26#include <linux/fs.h>
27#include <linux/sysfs.h>
28#include <linux/kernel.h>
29#include <linux/slab.h>
30#include <linux/vmalloc.h>
31#include <linux/elf.h>
32#include <linux/proc_fs.h>
33#include <linux/security.h>
34#include <linux/seq_file.h>
35#include <linux/syscalls.h>
36#include <linux/fcntl.h>
37#include <linux/rcupdate.h>
38#include <linux/capability.h>
39#include <linux/cpu.h>
40#include <linux/moduleparam.h>
41#include <linux/errno.h>
42#include <linux/err.h>
43#include <linux/vermagic.h>
44#include <linux/notifier.h>
45#include <linux/sched.h>
46#include <linux/device.h>
47#include <linux/string.h>
48#include <linux/mutex.h>
49#include <linux/rculist.h>
50#include <linux/uaccess.h>
51#include <asm/cacheflush.h>
52#include <linux/set_memory.h>
53#include <asm/mmu_context.h>
54#include <linux/license.h>
55#include <asm/sections.h>
56#include <linux/tracepoint.h>
57#include <linux/ftrace.h>
58#include <linux/livepatch.h>
59#include <linux/async.h>
60#include <linux/percpu.h>
61#include <linux/kmemleak.h>
62#include <linux/jump_label.h>
63#include <linux/pfn.h>
64#include <linux/bsearch.h>
65#include <linux/dynamic_debug.h>
66#include <linux/audit.h>
67#include <uapi/linux/module.h>
68#include "module-internal.h"
69
70#define CREATE_TRACE_POINTS
71#include <trace/events/module.h>
72
73#ifndef ARCH_SHF_SMALL
74#define ARCH_SHF_SMALL 0
75#endif
76
77/*
78 * Modules' sections will be aligned on page boundaries
79 * to ensure complete separation of code and data, but
80 * only when CONFIG_STRICT_MODULE_RWX=y
81 */
82#ifdef CONFIG_STRICT_MODULE_RWX
83# define debug_align(X) ALIGN(X, PAGE_SIZE)
84#else
85# define debug_align(X) (X)
86#endif
87
88/* If this is set, the section belongs in the init part of the module */
89#define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
90
91/*
92 * Mutex protects:
93 * 1) List of modules (also safely readable with preempt_disable),
94 * 2) module_use links,
95 * 3) module_addr_min/module_addr_max.
96 * (delete and add uses RCU list operations). */
97DEFINE_MUTEX(module_mutex);
98EXPORT_SYMBOL_GPL(module_mutex);
99static LIST_HEAD(modules);
100
101#ifdef CONFIG_MODULES_TREE_LOOKUP
102
103/*
104 * Use a latched RB-tree for __module_address(); this allows us to use
105 * RCU-sched lookups of the address from any context.
106 *
107 * This is conditional on PERF_EVENTS || TRACING because those can really hit
108 * __module_address() hard by doing a lot of stack unwinding; potentially from
109 * NMI context.
110 */
111
112static __always_inline unsigned long __mod_tree_val(struct latch_tree_node *n)
113{
114 struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
115
116 return (unsigned long)layout->base;
117}
118
119static __always_inline unsigned long __mod_tree_size(struct latch_tree_node *n)
120{
121 struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
122
123 return (unsigned long)layout->size;
124}
125
126static __always_inline bool
127mod_tree_less(struct latch_tree_node *a, struct latch_tree_node *b)
128{
129 return __mod_tree_val(a) < __mod_tree_val(b);
130}
131
132static __always_inline int
133mod_tree_comp(void *key, struct latch_tree_node *n)
134{
135 unsigned long val = (unsigned long)key;
136 unsigned long start, end;
137
138 start = __mod_tree_val(n);
139 if (val < start)
140 return -1;
141
142 end = start + __mod_tree_size(n);
143 if (val >= end)
144 return 1;
145
146 return 0;
147}
148
149static const struct latch_tree_ops mod_tree_ops = {
150 .less = mod_tree_less,
151 .comp = mod_tree_comp,
152};
153
154static struct mod_tree_root {
155 struct latch_tree_root root;
156 unsigned long addr_min;
157 unsigned long addr_max;
158} mod_tree __cacheline_aligned = {
159 .addr_min = -1UL,
160};
161
162#define module_addr_min mod_tree.addr_min
163#define module_addr_max mod_tree.addr_max
164
165static noinline void __mod_tree_insert(struct mod_tree_node *node)
166{
167 latch_tree_insert(&node->node, &mod_tree.root, &mod_tree_ops);
168}
169
170static void __mod_tree_remove(struct mod_tree_node *node)
171{
172 latch_tree_erase(&node->node, &mod_tree.root, &mod_tree_ops);
173}
174
175/*
176 * These modifications: insert, remove_init and remove; are serialized by the
177 * module_mutex.
178 */
179static void mod_tree_insert(struct module *mod)
180{
181 mod->core_layout.mtn.mod = mod;
182 mod->init_layout.mtn.mod = mod;
183
184 __mod_tree_insert(&mod->core_layout.mtn);
185 if (mod->init_layout.size)
186 __mod_tree_insert(&mod->init_layout.mtn);
187}
188
189static void mod_tree_remove_init(struct module *mod)
190{
191 if (mod->init_layout.size)
192 __mod_tree_remove(&mod->init_layout.mtn);
193}
194
195static void mod_tree_remove(struct module *mod)
196{
197 __mod_tree_remove(&mod->core_layout.mtn);
198 mod_tree_remove_init(mod);
199}
200
201static struct module *mod_find(unsigned long addr)
202{
203 struct latch_tree_node *ltn;
204
205 ltn = latch_tree_find((void *)addr, &mod_tree.root, &mod_tree_ops);
206 if (!ltn)
207 return NULL;
208
209 return container_of(ltn, struct mod_tree_node, node)->mod;
210}
211
212#else /* MODULES_TREE_LOOKUP */
213
214static unsigned long module_addr_min = -1UL, module_addr_max = 0;
215
216static void mod_tree_insert(struct module *mod) { }
217static void mod_tree_remove_init(struct module *mod) { }
218static void mod_tree_remove(struct module *mod) { }
219
220static struct module *mod_find(unsigned long addr)
221{
222 struct module *mod;
223
224 list_for_each_entry_rcu(mod, &modules, list) {
225 if (within_module(addr, mod))
226 return mod;
227 }
228
229 return NULL;
230}
231
232#endif /* MODULES_TREE_LOOKUP */
233
234/*
235 * Bounds of module text, for speeding up __module_address.
236 * Protected by module_mutex.
237 */
238static void __mod_update_bounds(void *base, unsigned int size)
239{
240 unsigned long min = (unsigned long)base;
241 unsigned long max = min + size;
242
243 if (min < module_addr_min)
244 module_addr_min = min;
245 if (max > module_addr_max)
246 module_addr_max = max;
247}
248
249static void mod_update_bounds(struct module *mod)
250{
251 __mod_update_bounds(mod->core_layout.base, mod->core_layout.size);
252 if (mod->init_layout.size)
253 __mod_update_bounds(mod->init_layout.base, mod->init_layout.size);
254}
255
256#ifdef CONFIG_KGDB_KDB
257struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
258#endif /* CONFIG_KGDB_KDB */
259
260static void module_assert_mutex(void)
261{
262 lockdep_assert_held(&module_mutex);
263}
264
265static void module_assert_mutex_or_preempt(void)
266{
267#ifdef CONFIG_LOCKDEP
268 if (unlikely(!debug_locks))
269 return;
270
271 WARN_ON_ONCE(!rcu_read_lock_sched_held() &&
272 !lockdep_is_held(&module_mutex));
273#endif
274}
275
276static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE);
277module_param(sig_enforce, bool_enable_only, 0644);
278
279/*
280 * Export sig_enforce kernel cmdline parameter to allow other subsystems rely
281 * on that instead of directly to CONFIG_MODULE_SIG_FORCE config.
282 */
283bool is_module_sig_enforced(void)
284{
285 return sig_enforce;
286}
287EXPORT_SYMBOL(is_module_sig_enforced);
288
289/* Block module loading/unloading? */
290int modules_disabled = 0;
291core_param(nomodule, modules_disabled, bint, 0);
292
293/* Waiting for a module to finish initializing? */
294static DECLARE_WAIT_QUEUE_HEAD(module_wq);
295
296static BLOCKING_NOTIFIER_HEAD(module_notify_list);
297
298int register_module_notifier(struct notifier_block *nb)
299{
300 return blocking_notifier_chain_register(&module_notify_list, nb);
301}
302EXPORT_SYMBOL(register_module_notifier);
303
304int unregister_module_notifier(struct notifier_block *nb)
305{
306 return blocking_notifier_chain_unregister(&module_notify_list, nb);
307}
308EXPORT_SYMBOL(unregister_module_notifier);
309
310/*
311 * We require a truly strong try_module_get(): 0 means success.
312 * Otherwise an error is returned due to ongoing or failed
313 * initialization etc.
314 */
315static inline int strong_try_module_get(struct module *mod)
316{
317 BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED);
318 if (mod && mod->state == MODULE_STATE_COMING)
319 return -EBUSY;
320 if (try_module_get(mod))
321 return 0;
322 else
323 return -ENOENT;
324}
325
326static inline void add_taint_module(struct module *mod, unsigned flag,
327 enum lockdep_ok lockdep_ok)
328{
329 add_taint(flag, lockdep_ok);
330 set_bit(flag, &mod->taints);
331}
332
333/*
334 * A thread that wants to hold a reference to a module only while it
335 * is running can call this to safely exit. nfsd and lockd use this.
336 */
337void __noreturn __module_put_and_exit(struct module *mod, long code)
338{
339 module_put(mod);
340 do_exit(code);
341}
342EXPORT_SYMBOL(__module_put_and_exit);
343
344/* Find a module section: 0 means not found. */
345static unsigned int find_sec(const struct load_info *info, const char *name)
346{
347 unsigned int i;
348
349 for (i = 1; i < info->hdr->e_shnum; i++) {
350 Elf_Shdr *shdr = &info->sechdrs[i];
351 /* Alloc bit cleared means "ignore it." */
352 if ((shdr->sh_flags & SHF_ALLOC)
353 && strcmp(info->secstrings + shdr->sh_name, name) == 0)
354 return i;
355 }
356 return 0;
357}
358
359/* Find a module section, or NULL. */
360static void *section_addr(const struct load_info *info, const char *name)
361{
362 /* Section 0 has sh_addr 0. */
363 return (void *)info->sechdrs[find_sec(info, name)].sh_addr;
364}
365
366/* Find a module section, or NULL. Fill in number of "objects" in section. */
367static void *section_objs(const struct load_info *info,
368 const char *name,
369 size_t object_size,
370 unsigned int *num)
371{
372 unsigned int sec = find_sec(info, name);
373
374 /* Section 0 has sh_addr 0 and sh_size 0. */
375 *num = info->sechdrs[sec].sh_size / object_size;
376 return (void *)info->sechdrs[sec].sh_addr;
377}
378
379/* Provided by the linker */
380extern const struct kernel_symbol __start___ksymtab[];
381extern const struct kernel_symbol __stop___ksymtab[];
382extern const struct kernel_symbol __start___ksymtab_gpl[];
383extern const struct kernel_symbol __stop___ksymtab_gpl[];
384extern const struct kernel_symbol __start___ksymtab_gpl_future[];
385extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
386extern const s32 __start___kcrctab[];
387extern const s32 __start___kcrctab_gpl[];
388extern const s32 __start___kcrctab_gpl_future[];
389#ifdef CONFIG_UNUSED_SYMBOLS
390extern const struct kernel_symbol __start___ksymtab_unused[];
391extern const struct kernel_symbol __stop___ksymtab_unused[];
392extern const struct kernel_symbol __start___ksymtab_unused_gpl[];
393extern const struct kernel_symbol __stop___ksymtab_unused_gpl[];
394extern const s32 __start___kcrctab_unused[];
395extern const s32 __start___kcrctab_unused_gpl[];
396#endif
397
398#ifndef CONFIG_MODVERSIONS
399#define symversion(base, idx) NULL
400#else
401#define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
402#endif
403
404static bool each_symbol_in_section(const struct symsearch *arr,
405 unsigned int arrsize,
406 struct module *owner,
407 bool (*fn)(const struct symsearch *syms,
408 struct module *owner,
409 void *data),
410 void *data)
411{
412 unsigned int j;
413
414 for (j = 0; j < arrsize; j++) {
415 if (fn(&arr[j], owner, data))
416 return true;
417 }
418
419 return false;
420}
421
422/* Returns true as soon as fn returns true, otherwise false. */
423bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
424 struct module *owner,
425 void *data),
426 void *data)
427{
428 struct module *mod;
429 static const struct symsearch arr[] = {
430 { __start___ksymtab, __stop___ksymtab, __start___kcrctab,
431 NOT_GPL_ONLY, false },
432 { __start___ksymtab_gpl, __stop___ksymtab_gpl,
433 __start___kcrctab_gpl,
434 GPL_ONLY, false },
435 { __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future,
436 __start___kcrctab_gpl_future,
437 WILL_BE_GPL_ONLY, false },
438#ifdef CONFIG_UNUSED_SYMBOLS
439 { __start___ksymtab_unused, __stop___ksymtab_unused,
440 __start___kcrctab_unused,
441 NOT_GPL_ONLY, true },
442 { __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl,
443 __start___kcrctab_unused_gpl,
444 GPL_ONLY, true },
445#endif
446 };
447
448 module_assert_mutex_or_preempt();
449
450 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data))
451 return true;
452
453 list_for_each_entry_rcu(mod, &modules, list) {
454 struct symsearch arr[] = {
455 { mod->syms, mod->syms + mod->num_syms, mod->crcs,
456 NOT_GPL_ONLY, false },
457 { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
458 mod->gpl_crcs,
459 GPL_ONLY, false },
460 { mod->gpl_future_syms,
461 mod->gpl_future_syms + mod->num_gpl_future_syms,
462 mod->gpl_future_crcs,
463 WILL_BE_GPL_ONLY, false },
464#ifdef CONFIG_UNUSED_SYMBOLS
465 { mod->unused_syms,
466 mod->unused_syms + mod->num_unused_syms,
467 mod->unused_crcs,
468 NOT_GPL_ONLY, true },
469 { mod->unused_gpl_syms,
470 mod->unused_gpl_syms + mod->num_unused_gpl_syms,
471 mod->unused_gpl_crcs,
472 GPL_ONLY, true },
473#endif
474 };
475
476 if (mod->state == MODULE_STATE_UNFORMED)
477 continue;
478
479 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data))
480 return true;
481 }
482 return false;
483}
484EXPORT_SYMBOL_GPL(each_symbol_section);
485
486struct find_symbol_arg {
487 /* Input */
488 const char *name;
489 bool gplok;
490 bool warn;
491
492 /* Output */
493 struct module *owner;
494 const s32 *crc;
495 const struct kernel_symbol *sym;
496};
497
498static bool check_exported_symbol(const struct symsearch *syms,
499 struct module *owner,
500 unsigned int symnum, void *data)
501{
502 struct find_symbol_arg *fsa = data;
503
504 if (!fsa->gplok) {
505 if (syms->licence == GPL_ONLY)
506 return false;
507 if (syms->licence == WILL_BE_GPL_ONLY && fsa->warn) {
508 pr_warn("Symbol %s is being used by a non-GPL module, "
509 "which will not be allowed in the future\n",
510 fsa->name);
511 }
512 }
513
514#ifdef CONFIG_UNUSED_SYMBOLS
515 if (syms->unused && fsa->warn) {
516 pr_warn("Symbol %s is marked as UNUSED, however this module is "
517 "using it.\n", fsa->name);
518 pr_warn("This symbol will go away in the future.\n");
519 pr_warn("Please evaluate if this is the right api to use and "
520 "if it really is, submit a report to the linux kernel "
521 "mailing list together with submitting your code for "
522 "inclusion.\n");
523 }
524#endif
525
526 fsa->owner = owner;
527 fsa->crc = symversion(syms->crcs, symnum);
528 fsa->sym = &syms->start[symnum];
529 return true;
530}
531
532static unsigned long kernel_symbol_value(const struct kernel_symbol *sym)
533{
534#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
535 return (unsigned long)offset_to_ptr(&sym->value_offset);
536#else
537 return sym->value;
538#endif
539}
540
541static const char *kernel_symbol_name(const struct kernel_symbol *sym)
542{
543#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
544 return offset_to_ptr(&sym->name_offset);
545#else
546 return sym->name;
547#endif
548}
549
550static int cmp_name(const void *va, const void *vb)
551{
552 const char *a;
553 const struct kernel_symbol *b;
554 a = va; b = vb;
555 return strcmp(a, kernel_symbol_name(b));
556}
557
558static bool find_exported_symbol_in_section(const struct symsearch *syms,
559 struct module *owner,
560 void *data)
561{
562 struct find_symbol_arg *fsa = data;
563 struct kernel_symbol *sym;
564
565 sym = bsearch(fsa->name, syms->start, syms->stop - syms->start,
566 sizeof(struct kernel_symbol), cmp_name);
567
568 if (sym != NULL && check_exported_symbol(syms, owner,
569 sym - syms->start, data))
570 return true;
571
572 return false;
573}
574
575/* Find an exported symbol and return it, along with, (optional) crc and
576 * (optional) module which owns it. Needs preempt disabled or module_mutex. */
577const struct kernel_symbol *find_symbol(const char *name,
578 struct module **owner,
579 const s32 **crc,
580 bool gplok,
581 bool warn)
582{
583 struct find_symbol_arg fsa;
584
585 fsa.name = name;
586 fsa.gplok = gplok;
587 fsa.warn = warn;
588
589 if (each_symbol_section(find_exported_symbol_in_section, &fsa)) {
590 if (owner)
591 *owner = fsa.owner;
592 if (crc)
593 *crc = fsa.crc;
594 return fsa.sym;
595 }
596
597 pr_debug("Failed to find symbol %s\n", name);
598 return NULL;
599}
600EXPORT_SYMBOL_GPL(find_symbol);
601
602/*
603 * Search for module by name: must hold module_mutex (or preempt disabled
604 * for read-only access).
605 */
606static 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_or_preempt();
612
613 list_for_each_entry_rcu(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
622struct module *find_module(const char *name)
623{
624 module_assert_mutex();
625 return find_module_all(name, strlen(name), false);
626}
627EXPORT_SYMBOL_GPL(find_module);
628
629#ifdef CONFIG_SMP
630
631static inline void __percpu *mod_percpu(struct module *mod)
632{
633 return mod->percpu;
634}
635
636static int percpu_modalloc(struct module *mod, struct load_info *info)
637{
638 Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu];
639 unsigned long align = pcpusec->sh_addralign;
640
641 if (!pcpusec->sh_size)
642 return 0;
643
644 if (align > PAGE_SIZE) {
645 pr_warn("%s: per-cpu alignment %li > %li\n",
646 mod->name, align, PAGE_SIZE);
647 align = PAGE_SIZE;
648 }
649
650 mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align);
651 if (!mod->percpu) {
652 pr_warn("%s: Could not allocate %lu bytes percpu data\n",
653 mod->name, (unsigned long)pcpusec->sh_size);
654 return -ENOMEM;
655 }
656 mod->percpu_size = pcpusec->sh_size;
657 return 0;
658}
659
660static void percpu_modfree(struct module *mod)
661{
662 free_percpu(mod->percpu);
663}
664
665static unsigned int find_pcpusec(struct load_info *info)
666{
667 return find_sec(info, ".data..percpu");
668}
669
670static void percpu_modcopy(struct module *mod,
671 const void *from, unsigned long size)
672{
673 int cpu;
674
675 for_each_possible_cpu(cpu)
676 memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
677}
678
679bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
680{
681 struct module *mod;
682 unsigned int cpu;
683
684 preempt_disable();
685
686 list_for_each_entry_rcu(mod, &modules, list) {
687 if (mod->state == MODULE_STATE_UNFORMED)
688 continue;
689 if (!mod->percpu_size)
690 continue;
691 for_each_possible_cpu(cpu) {
692 void *start = per_cpu_ptr(mod->percpu, cpu);
693 void *va = (void *)addr;
694
695 if (va >= start && va < start + mod->percpu_size) {
696 if (can_addr) {
697 *can_addr = (unsigned long) (va - start);
698 *can_addr += (unsigned long)
699 per_cpu_ptr(mod->percpu,
700 get_boot_cpu_id());
701 }
702 preempt_enable();
703 return true;
704 }
705 }
706 }
707
708 preempt_enable();
709 return false;
710}
711
712/**
713 * is_module_percpu_address - test whether address is from module static percpu
714 * @addr: address to test
715 *
716 * Test whether @addr belongs to module static percpu area.
717 *
718 * RETURNS:
719 * %true if @addr is from module static percpu area
720 */
721bool is_module_percpu_address(unsigned long addr)
722{
723 return __is_module_percpu_address(addr, NULL);
724}
725
726#else /* ... !CONFIG_SMP */
727
728static inline void __percpu *mod_percpu(struct module *mod)
729{
730 return NULL;
731}
732static int percpu_modalloc(struct module *mod, struct load_info *info)
733{
734 /* UP modules shouldn't have this section: ENOMEM isn't quite right */
735 if (info->sechdrs[info->index.pcpu].sh_size != 0)
736 return -ENOMEM;
737 return 0;
738}
739static inline void percpu_modfree(struct module *mod)
740{
741}
742static unsigned int find_pcpusec(struct load_info *info)
743{
744 return 0;
745}
746static inline void percpu_modcopy(struct module *mod,
747 const void *from, unsigned long size)
748{
749 /* pcpusec should be 0, and size of that section should be 0. */
750 BUG_ON(size != 0);
751}
752bool is_module_percpu_address(unsigned long addr)
753{
754 return false;
755}
756
757bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
758{
759 return false;
760}
761
762#endif /* CONFIG_SMP */
763
764#define MODINFO_ATTR(field) \
765static void setup_modinfo_##field(struct module *mod, const char *s) \
766{ \
767 mod->field = kstrdup(s, GFP_KERNEL); \
768} \
769static ssize_t show_modinfo_##field(struct module_attribute *mattr, \
770 struct module_kobject *mk, char *buffer) \
771{ \
772 return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field); \
773} \
774static int modinfo_##field##_exists(struct module *mod) \
775{ \
776 return mod->field != NULL; \
777} \
778static void free_modinfo_##field(struct module *mod) \
779{ \
780 kfree(mod->field); \
781 mod->field = NULL; \
782} \
783static struct module_attribute modinfo_##field = { \
784 .attr = { .name = __stringify(field), .mode = 0444 }, \
785 .show = show_modinfo_##field, \
786 .setup = setup_modinfo_##field, \
787 .test = modinfo_##field##_exists, \
788 .free = free_modinfo_##field, \
789};
790
791MODINFO_ATTR(version);
792MODINFO_ATTR(srcversion);
793
794static char last_unloaded_module[MODULE_NAME_LEN+1];
795
796#ifdef CONFIG_MODULE_UNLOAD
797
798EXPORT_TRACEPOINT_SYMBOL(module_get);
799
800/* MODULE_REF_BASE is the base reference count by kmodule loader. */
801#define MODULE_REF_BASE 1
802
803/* Init the unload section of the module. */
804static int module_unload_init(struct module *mod)
805{
806 /*
807 * Initialize reference counter to MODULE_REF_BASE.
808 * refcnt == 0 means module is going.
809 */
810 atomic_set(&mod->refcnt, MODULE_REF_BASE);
811
812 INIT_LIST_HEAD(&mod->source_list);
813 INIT_LIST_HEAD(&mod->target_list);
814
815 /* Hold reference count during initialization. */
816 atomic_inc(&mod->refcnt);
817
818 return 0;
819}
820
821/* Does a already use b? */
822static int already_uses(struct module *a, struct module *b)
823{
824 struct module_use *use;
825
826 list_for_each_entry(use, &b->source_list, source_list) {
827 if (use->source == a) {
828 pr_debug("%s uses %s!\n", a->name, b->name);
829 return 1;
830 }
831 }
832 pr_debug("%s does not use %s!\n", a->name, b->name);
833 return 0;
834}
835
836/*
837 * Module a uses b
838 * - we add 'a' as a "source", 'b' as a "target" of module use
839 * - the module_use is added to the list of 'b' sources (so
840 * 'b' can walk the list to see who sourced them), and of 'a'
841 * targets (so 'a' can see what modules it targets).
842 */
843static int add_module_usage(struct module *a, struct module *b)
844{
845 struct module_use *use;
846
847 pr_debug("Allocating new usage for %s.\n", a->name);
848 use = kmalloc(sizeof(*use), GFP_ATOMIC);
849 if (!use)
850 return -ENOMEM;
851
852 use->source = a;
853 use->target = b;
854 list_add(&use->source_list, &b->source_list);
855 list_add(&use->target_list, &a->target_list);
856 return 0;
857}
858
859/* Module a uses b: caller needs module_mutex() */
860int ref_module(struct module *a, struct module *b)
861{
862 int err;
863
864 if (b == NULL || already_uses(a, b))
865 return 0;
866
867 /* If module isn't available, we fail. */
868 err = strong_try_module_get(b);
869 if (err)
870 return err;
871
872 err = add_module_usage(a, b);
873 if (err) {
874 module_put(b);
875 return err;
876 }
877 return 0;
878}
879EXPORT_SYMBOL_GPL(ref_module);
880
881/* Clear the unload stuff of the module. */
882static void module_unload_free(struct module *mod)
883{
884 struct module_use *use, *tmp;
885
886 mutex_lock(&module_mutex);
887 list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
888 struct module *i = use->target;
889 pr_debug("%s unusing %s\n", mod->name, i->name);
890 module_put(i);
891 list_del(&use->source_list);
892 list_del(&use->target_list);
893 kfree(use);
894 }
895 mutex_unlock(&module_mutex);
896}
897
898#ifdef CONFIG_MODULE_FORCE_UNLOAD
899static inline int try_force_unload(unsigned int flags)
900{
901 int ret = (flags & O_TRUNC);
902 if (ret)
903 add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE);
904 return ret;
905}
906#else
907static inline int try_force_unload(unsigned int flags)
908{
909 return 0;
910}
911#endif /* CONFIG_MODULE_FORCE_UNLOAD */
912
913/* Try to release refcount of module, 0 means success. */
914static int try_release_module_ref(struct module *mod)
915{
916 int ret;
917
918 /* Try to decrement refcnt which we set at loading */
919 ret = atomic_sub_return(MODULE_REF_BASE, &mod->refcnt);
920 BUG_ON(ret < 0);
921 if (ret)
922 /* Someone can put this right now, recover with checking */
923 ret = atomic_add_unless(&mod->refcnt, MODULE_REF_BASE, 0);
924
925 return ret;
926}
927
928static int try_stop_module(struct module *mod, int flags, int *forced)
929{
930 /* If it's not unused, quit unless we're forcing. */
931 if (try_release_module_ref(mod) != 0) {
932 *forced = try_force_unload(flags);
933 if (!(*forced))
934 return -EWOULDBLOCK;
935 }
936
937 /* Mark it as dying. */
938 mod->state = MODULE_STATE_GOING;
939
940 return 0;
941}
942
943/**
944 * module_refcount - return the refcount or -1 if unloading
945 *
946 * @mod: the module we're checking
947 *
948 * Returns:
949 * -1 if the module is in the process of unloading
950 * otherwise the number of references in the kernel to the module
951 */
952int module_refcount(struct module *mod)
953{
954 return atomic_read(&mod->refcnt) - MODULE_REF_BASE;
955}
956EXPORT_SYMBOL(module_refcount);
957
958/* This exists whether we can unload or not */
959static void free_module(struct module *mod);
960
961SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
962 unsigned int, flags)
963{
964 struct module *mod;
965 char name[MODULE_NAME_LEN];
966 int ret, forced = 0;
967
968 if (!capable(CAP_SYS_MODULE) || modules_disabled)
969 return -EPERM;
970
971 if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
972 return -EFAULT;
973 name[MODULE_NAME_LEN-1] = '\0';
974
975 audit_log_kern_module(name);
976
977 if (mutex_lock_interruptible(&module_mutex) != 0)
978 return -EINTR;
979
980 mod = find_module(name);
981 if (!mod) {
982 ret = -ENOENT;
983 goto out;
984 }
985
986 if (!list_empty(&mod->source_list)) {
987 /* Other modules depend on us: get rid of them first. */
988 ret = -EWOULDBLOCK;
989 goto out;
990 }
991
992 /* Doing init or already dying? */
993 if (mod->state != MODULE_STATE_LIVE) {
994 /* FIXME: if (force), slam module count damn the torpedoes */
995 pr_debug("%s already dying\n", mod->name);
996 ret = -EBUSY;
997 goto out;
998 }
999
1000 /* If it has an init func, it must have an exit func to unload */
1001 if (mod->init && !mod->exit) {
1002 forced = try_force_unload(flags);
1003 if (!forced) {
1004 /* This module can't be removed */
1005 ret = -EBUSY;
1006 goto out;
1007 }
1008 }
1009
1010 /* Stop the machine so refcounts can't move and disable module. */
1011 ret = try_stop_module(mod, flags, &forced);
1012 if (ret != 0)
1013 goto out;
1014
1015 mutex_unlock(&module_mutex);
1016 /* Final destruction now no one is using it. */
1017 if (mod->exit != NULL)
1018 mod->exit();
1019 blocking_notifier_call_chain(&module_notify_list,
1020 MODULE_STATE_GOING, mod);
1021 klp_module_going(mod);
1022 ftrace_release_mod(mod);
1023
1024 async_synchronize_full();
1025
1026 /* Store the name of the last unloaded module for diagnostic purposes */
1027 strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
1028
1029 free_module(mod);
1030 return 0;
1031out:
1032 mutex_unlock(&module_mutex);
1033 return ret;
1034}
1035
1036static inline void print_unload_info(struct seq_file *m, struct module *mod)
1037{
1038 struct module_use *use;
1039 int printed_something = 0;
1040
1041 seq_printf(m, " %i ", module_refcount(mod));
1042
1043 /*
1044 * Always include a trailing , so userspace can differentiate
1045 * between this and the old multi-field proc format.
1046 */
1047 list_for_each_entry(use, &mod->source_list, source_list) {
1048 printed_something = 1;
1049 seq_printf(m, "%s,", use->source->name);
1050 }
1051
1052 if (mod->init != NULL && mod->exit == NULL) {
1053 printed_something = 1;
1054 seq_puts(m, "[permanent],");
1055 }
1056
1057 if (!printed_something)
1058 seq_puts(m, "-");
1059}
1060
1061void __symbol_put(const char *symbol)
1062{
1063 struct module *owner;
1064
1065 preempt_disable();
1066 if (!find_symbol(symbol, &owner, NULL, true, false))
1067 BUG();
1068 module_put(owner);
1069 preempt_enable();
1070}
1071EXPORT_SYMBOL(__symbol_put);
1072
1073/* Note this assumes addr is a function, which it currently always is. */
1074void symbol_put_addr(void *addr)
1075{
1076 struct module *modaddr;
1077 unsigned long a = (unsigned long)dereference_function_descriptor(addr);
1078
1079 if (core_kernel_text(a))
1080 return;
1081
1082 /*
1083 * Even though we hold a reference on the module; we still need to
1084 * disable preemption in order to safely traverse the data structure.
1085 */
1086 preempt_disable();
1087 modaddr = __module_text_address(a);
1088 BUG_ON(!modaddr);
1089 module_put(modaddr);
1090 preempt_enable();
1091}
1092EXPORT_SYMBOL_GPL(symbol_put_addr);
1093
1094static ssize_t show_refcnt(struct module_attribute *mattr,
1095 struct module_kobject *mk, char *buffer)
1096{
1097 return sprintf(buffer, "%i\n", module_refcount(mk->mod));
1098}
1099
1100static struct module_attribute modinfo_refcnt =
1101 __ATTR(refcnt, 0444, show_refcnt, NULL);
1102
1103void __module_get(struct module *module)
1104{
1105 if (module) {
1106 preempt_disable();
1107 atomic_inc(&module->refcnt);
1108 trace_module_get(module, _RET_IP_);
1109 preempt_enable();
1110 }
1111}
1112EXPORT_SYMBOL(__module_get);
1113
1114bool try_module_get(struct module *module)
1115{
1116 bool ret = true;
1117
1118 if (module) {
1119 preempt_disable();
1120 /* Note: here, we can fail to get a reference */
1121 if (likely(module_is_live(module) &&
1122 atomic_inc_not_zero(&module->refcnt) != 0))
1123 trace_module_get(module, _RET_IP_);
1124 else
1125 ret = false;
1126
1127 preempt_enable();
1128 }
1129 return ret;
1130}
1131EXPORT_SYMBOL(try_module_get);
1132
1133void module_put(struct module *module)
1134{
1135 int ret;
1136
1137 if (module) {
1138 preempt_disable();
1139 ret = atomic_dec_if_positive(&module->refcnt);
1140 WARN_ON(ret < 0); /* Failed to put refcount */
1141 trace_module_put(module, _RET_IP_);
1142 preempt_enable();
1143 }
1144}
1145EXPORT_SYMBOL(module_put);
1146
1147#else /* !CONFIG_MODULE_UNLOAD */
1148static inline void print_unload_info(struct seq_file *m, struct module *mod)
1149{
1150 /* We don't know the usage count, or what modules are using. */
1151 seq_puts(m, " - -");
1152}
1153
1154static inline void module_unload_free(struct module *mod)
1155{
1156}
1157
1158int ref_module(struct module *a, struct module *b)
1159{
1160 return strong_try_module_get(b);
1161}
1162EXPORT_SYMBOL_GPL(ref_module);
1163
1164static inline int module_unload_init(struct module *mod)
1165{
1166 return 0;
1167}
1168#endif /* CONFIG_MODULE_UNLOAD */
1169
1170static size_t module_flags_taint(struct module *mod, char *buf)
1171{
1172 size_t l = 0;
1173 int i;
1174
1175 for (i = 0; i < TAINT_FLAGS_COUNT; i++) {
1176 if (taint_flags[i].module && test_bit(i, &mod->taints))
1177 buf[l++] = taint_flags[i].c_true;
1178 }
1179
1180 return l;
1181}
1182
1183static ssize_t show_initstate(struct module_attribute *mattr,
1184 struct module_kobject *mk, char *buffer)
1185{
1186 const char *state = "unknown";
1187
1188 switch (mk->mod->state) {
1189 case MODULE_STATE_LIVE:
1190 state = "live";
1191 break;
1192 case MODULE_STATE_COMING:
1193 state = "coming";
1194 break;
1195 case MODULE_STATE_GOING:
1196 state = "going";
1197 break;
1198 default:
1199 BUG();
1200 }
1201 return sprintf(buffer, "%s\n", state);
1202}
1203
1204static struct module_attribute modinfo_initstate =
1205 __ATTR(initstate, 0444, show_initstate, NULL);
1206
1207static ssize_t store_uevent(struct module_attribute *mattr,
1208 struct module_kobject *mk,
1209 const char *buffer, size_t count)
1210{
1211 int rc;
1212
1213 rc = kobject_synth_uevent(&mk->kobj, buffer, count);
1214 return rc ? rc : count;
1215}
1216
1217struct module_attribute module_uevent =
1218 __ATTR(uevent, 0200, NULL, store_uevent);
1219
1220static ssize_t show_coresize(struct module_attribute *mattr,
1221 struct module_kobject *mk, char *buffer)
1222{
1223 return sprintf(buffer, "%u\n", mk->mod->core_layout.size);
1224}
1225
1226static struct module_attribute modinfo_coresize =
1227 __ATTR(coresize, 0444, show_coresize, NULL);
1228
1229static ssize_t show_initsize(struct module_attribute *mattr,
1230 struct module_kobject *mk, char *buffer)
1231{
1232 return sprintf(buffer, "%u\n", mk->mod->init_layout.size);
1233}
1234
1235static struct module_attribute modinfo_initsize =
1236 __ATTR(initsize, 0444, show_initsize, NULL);
1237
1238static ssize_t show_taint(struct module_attribute *mattr,
1239 struct module_kobject *mk, char *buffer)
1240{
1241 size_t l;
1242
1243 l = module_flags_taint(mk->mod, buffer);
1244 buffer[l++] = '\n';
1245 return l;
1246}
1247
1248static struct module_attribute modinfo_taint =
1249 __ATTR(taint, 0444, show_taint, NULL);
1250
1251static struct module_attribute *modinfo_attrs[] = {
1252 &module_uevent,
1253 &modinfo_version,
1254 &modinfo_srcversion,
1255 &modinfo_initstate,
1256 &modinfo_coresize,
1257 &modinfo_initsize,
1258 &modinfo_taint,
1259#ifdef CONFIG_MODULE_UNLOAD
1260 &modinfo_refcnt,
1261#endif
1262 NULL,
1263};
1264
1265static const char vermagic[] = VERMAGIC_STRING;
1266
1267static int try_to_force_load(struct module *mod, const char *reason)
1268{
1269#ifdef CONFIG_MODULE_FORCE_LOAD
1270 if (!test_taint(TAINT_FORCED_MODULE))
1271 pr_warn("%s: %s: kernel tainted.\n", mod->name, reason);
1272 add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
1273 return 0;
1274#else
1275 return -ENOEXEC;
1276#endif
1277}
1278
1279#ifdef CONFIG_MODVERSIONS
1280
1281static u32 resolve_rel_crc(const s32 *crc)
1282{
1283 return *(u32 *)((void *)crc + *crc);
1284}
1285
1286static int check_version(const struct load_info *info,
1287 const char *symname,
1288 struct module *mod,
1289 const s32 *crc)
1290{
1291 Elf_Shdr *sechdrs = info->sechdrs;
1292 unsigned int versindex = info->index.vers;
1293 unsigned int i, num_versions;
1294 struct modversion_info *versions;
1295
1296 /* Exporting module didn't supply crcs? OK, we're already tainted. */
1297 if (!crc)
1298 return 1;
1299
1300 /* No versions at all? modprobe --force does this. */
1301 if (versindex == 0)
1302 return try_to_force_load(mod, symname) == 0;
1303
1304 versions = (void *) sechdrs[versindex].sh_addr;
1305 num_versions = sechdrs[versindex].sh_size
1306 / sizeof(struct modversion_info);
1307
1308 for (i = 0; i < num_versions; i++) {
1309 u32 crcval;
1310
1311 if (strcmp(versions[i].name, symname) != 0)
1312 continue;
1313
1314 if (IS_ENABLED(CONFIG_MODULE_REL_CRCS))
1315 crcval = resolve_rel_crc(crc);
1316 else
1317 crcval = *crc;
1318 if (versions[i].crc == crcval)
1319 return 1;
1320 pr_debug("Found checksum %X vs module %lX\n",
1321 crcval, versions[i].crc);
1322 goto bad_version;
1323 }
1324
1325 /* Broken toolchain. Warn once, then let it go.. */
1326 pr_warn_once("%s: no symbol version for %s\n", info->name, symname);
1327 return 1;
1328
1329bad_version:
1330 pr_warn("%s: disagrees about version of symbol %s\n",
1331 info->name, symname);
1332 return 0;
1333}
1334
1335static inline int check_modstruct_version(const struct load_info *info,
1336 struct module *mod)
1337{
1338 const s32 *crc;
1339
1340 /*
1341 * Since this should be found in kernel (which can't be removed), no
1342 * locking is necessary -- use preempt_disable() to placate lockdep.
1343 */
1344 preempt_disable();
1345 if (!find_symbol("module_layout", NULL, &crc, true, false)) {
1346 preempt_enable();
1347 BUG();
1348 }
1349 preempt_enable();
1350 return check_version(info, "module_layout", mod, crc);
1351}
1352
1353/* First part is kernel version, which we ignore if module has crcs. */
1354static inline int same_magic(const char *amagic, const char *bmagic,
1355 bool has_crcs)
1356{
1357 if (has_crcs) {
1358 amagic += strcspn(amagic, " ");
1359 bmagic += strcspn(bmagic, " ");
1360 }
1361 return strcmp(amagic, bmagic) == 0;
1362}
1363#else
1364static inline int check_version(const struct load_info *info,
1365 const char *symname,
1366 struct module *mod,
1367 const s32 *crc)
1368{
1369 return 1;
1370}
1371
1372static inline int check_modstruct_version(const struct load_info *info,
1373 struct module *mod)
1374{
1375 return 1;
1376}
1377
1378static inline int same_magic(const char *amagic, const char *bmagic,
1379 bool has_crcs)
1380{
1381 return strcmp(amagic, bmagic) == 0;
1382}
1383#endif /* CONFIG_MODVERSIONS */
1384
1385/* Resolve a symbol for this module. I.e. if we find one, record usage. */
1386static const struct kernel_symbol *resolve_symbol(struct module *mod,
1387 const struct load_info *info,
1388 const char *name,
1389 char ownername[])
1390{
1391 struct module *owner;
1392 const struct kernel_symbol *sym;
1393 const s32 *crc;
1394 int err;
1395
1396 /*
1397 * The module_mutex should not be a heavily contended lock;
1398 * if we get the occasional sleep here, we'll go an extra iteration
1399 * in the wait_event_interruptible(), which is harmless.
1400 */
1401 sched_annotate_sleep();
1402 mutex_lock(&module_mutex);
1403 sym = find_symbol(name, &owner, &crc,
1404 !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
1405 if (!sym)
1406 goto unlock;
1407
1408 if (!check_version(info, name, mod, crc)) {
1409 sym = ERR_PTR(-EINVAL);
1410 goto getname;
1411 }
1412
1413 err = ref_module(mod, owner);
1414 if (err) {
1415 sym = ERR_PTR(err);
1416 goto getname;
1417 }
1418
1419getname:
1420 /* We must make copy under the lock if we failed to get ref. */
1421 strncpy(ownername, module_name(owner), MODULE_NAME_LEN);
1422unlock:
1423 mutex_unlock(&module_mutex);
1424 return sym;
1425}
1426
1427static const struct kernel_symbol *
1428resolve_symbol_wait(struct module *mod,
1429 const struct load_info *info,
1430 const char *name)
1431{
1432 const struct kernel_symbol *ksym;
1433 char owner[MODULE_NAME_LEN];
1434
1435 if (wait_event_interruptible_timeout(module_wq,
1436 !IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
1437 || PTR_ERR(ksym) != -EBUSY,
1438 30 * HZ) <= 0) {
1439 pr_warn("%s: gave up waiting for init of module %s.\n",
1440 mod->name, owner);
1441 }
1442 return ksym;
1443}
1444
1445/*
1446 * /sys/module/foo/sections stuff
1447 * J. Corbet <corbet@lwn.net>
1448 */
1449#ifdef CONFIG_SYSFS
1450
1451#ifdef CONFIG_KALLSYMS
1452static inline bool sect_empty(const Elf_Shdr *sect)
1453{
1454 return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
1455}
1456
1457struct module_sect_attr {
1458 struct module_attribute mattr;
1459 char *name;
1460 unsigned long address;
1461};
1462
1463struct module_sect_attrs {
1464 struct attribute_group grp;
1465 unsigned int nsections;
1466 struct module_sect_attr attrs[0];
1467};
1468
1469static ssize_t module_sect_show(struct module_attribute *mattr,
1470 struct module_kobject *mk, char *buf)
1471{
1472 struct module_sect_attr *sattr =
1473 container_of(mattr, struct module_sect_attr, mattr);
1474 return sprintf(buf, "0x%px\n", kptr_restrict < 2 ?
1475 (void *)sattr->address : NULL);
1476}
1477
1478static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
1479{
1480 unsigned int section;
1481
1482 for (section = 0; section < sect_attrs->nsections; section++)
1483 kfree(sect_attrs->attrs[section].name);
1484 kfree(sect_attrs);
1485}
1486
1487static void add_sect_attrs(struct module *mod, const struct load_info *info)
1488{
1489 unsigned int nloaded = 0, i, size[2];
1490 struct module_sect_attrs *sect_attrs;
1491 struct module_sect_attr *sattr;
1492 struct attribute **gattr;
1493
1494 /* Count loaded sections and allocate structures */
1495 for (i = 0; i < info->hdr->e_shnum; i++)
1496 if (!sect_empty(&info->sechdrs[i]))
1497 nloaded++;
1498 size[0] = ALIGN(sizeof(*sect_attrs)
1499 + nloaded * sizeof(sect_attrs->attrs[0]),
1500 sizeof(sect_attrs->grp.attrs[0]));
1501 size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]);
1502 sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
1503 if (sect_attrs == NULL)
1504 return;
1505
1506 /* Setup section attributes. */
1507 sect_attrs->grp.name = "sections";
1508 sect_attrs->grp.attrs = (void *)sect_attrs + size[0];
1509
1510 sect_attrs->nsections = 0;
1511 sattr = &sect_attrs->attrs[0];
1512 gattr = &sect_attrs->grp.attrs[0];
1513 for (i = 0; i < info->hdr->e_shnum; i++) {
1514 Elf_Shdr *sec = &info->sechdrs[i];
1515 if (sect_empty(sec))
1516 continue;
1517 sattr->address = sec->sh_addr;
1518 sattr->name = kstrdup(info->secstrings + sec->sh_name,
1519 GFP_KERNEL);
1520 if (sattr->name == NULL)
1521 goto out;
1522 sect_attrs->nsections++;
1523 sysfs_attr_init(&sattr->mattr.attr);
1524 sattr->mattr.show = module_sect_show;
1525 sattr->mattr.store = NULL;
1526 sattr->mattr.attr.name = sattr->name;
1527 sattr->mattr.attr.mode = S_IRUSR;
1528 *(gattr++) = &(sattr++)->mattr.attr;
1529 }
1530 *gattr = NULL;
1531
1532 if (sysfs_create_group(&mod->mkobj.kobj, &sect_attrs->grp))
1533 goto out;
1534
1535 mod->sect_attrs = sect_attrs;
1536 return;
1537 out:
1538 free_sect_attrs(sect_attrs);
1539}
1540
1541static void remove_sect_attrs(struct module *mod)
1542{
1543 if (mod->sect_attrs) {
1544 sysfs_remove_group(&mod->mkobj.kobj,
1545 &mod->sect_attrs->grp);
1546 /* We are positive that no one is using any sect attrs
1547 * at this point. Deallocate immediately. */
1548 free_sect_attrs(mod->sect_attrs);
1549 mod->sect_attrs = NULL;
1550 }
1551}
1552
1553/*
1554 * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
1555 */
1556
1557struct module_notes_attrs {
1558 struct kobject *dir;
1559 unsigned int notes;
1560 struct bin_attribute attrs[0];
1561};
1562
1563static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
1564 struct bin_attribute *bin_attr,
1565 char *buf, loff_t pos, size_t count)
1566{
1567 /*
1568 * The caller checked the pos and count against our size.
1569 */
1570 memcpy(buf, bin_attr->private + pos, count);
1571 return count;
1572}
1573
1574static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
1575 unsigned int i)
1576{
1577 if (notes_attrs->dir) {
1578 while (i-- > 0)
1579 sysfs_remove_bin_file(notes_attrs->dir,
1580 &notes_attrs->attrs[i]);
1581 kobject_put(notes_attrs->dir);
1582 }
1583 kfree(notes_attrs);
1584}
1585
1586static void add_notes_attrs(struct module *mod, const struct load_info *info)
1587{
1588 unsigned int notes, loaded, i;
1589 struct module_notes_attrs *notes_attrs;
1590 struct bin_attribute *nattr;
1591
1592 /* failed to create section attributes, so can't create notes */
1593 if (!mod->sect_attrs)
1594 return;
1595
1596 /* Count notes sections and allocate structures. */
1597 notes = 0;
1598 for (i = 0; i < info->hdr->e_shnum; i++)
1599 if (!sect_empty(&info->sechdrs[i]) &&
1600 (info->sechdrs[i].sh_type == SHT_NOTE))
1601 ++notes;
1602
1603 if (notes == 0)
1604 return;
1605
1606 notes_attrs = kzalloc(struct_size(notes_attrs, attrs, notes),
1607 GFP_KERNEL);
1608 if (notes_attrs == NULL)
1609 return;
1610
1611 notes_attrs->notes = notes;
1612 nattr = &notes_attrs->attrs[0];
1613 for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
1614 if (sect_empty(&info->sechdrs[i]))
1615 continue;
1616 if (info->sechdrs[i].sh_type == SHT_NOTE) {
1617 sysfs_bin_attr_init(nattr);
1618 nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
1619 nattr->attr.mode = S_IRUGO;
1620 nattr->size = info->sechdrs[i].sh_size;
1621 nattr->private = (void *) info->sechdrs[i].sh_addr;
1622 nattr->read = module_notes_read;
1623 ++nattr;
1624 }
1625 ++loaded;
1626 }
1627
1628 notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
1629 if (!notes_attrs->dir)
1630 goto out;
1631
1632 for (i = 0; i < notes; ++i)
1633 if (sysfs_create_bin_file(notes_attrs->dir,
1634 &notes_attrs->attrs[i]))
1635 goto out;
1636
1637 mod->notes_attrs = notes_attrs;
1638 return;
1639
1640 out:
1641 free_notes_attrs(notes_attrs, i);
1642}
1643
1644static void remove_notes_attrs(struct module *mod)
1645{
1646 if (mod->notes_attrs)
1647 free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
1648}
1649
1650#else
1651
1652static inline void add_sect_attrs(struct module *mod,
1653 const struct load_info *info)
1654{
1655}
1656
1657static inline void remove_sect_attrs(struct module *mod)
1658{
1659}
1660
1661static inline void add_notes_attrs(struct module *mod,
1662 const struct load_info *info)
1663{
1664}
1665
1666static inline void remove_notes_attrs(struct module *mod)
1667{
1668}
1669#endif /* CONFIG_KALLSYMS */
1670
1671static void del_usage_links(struct module *mod)
1672{
1673#ifdef CONFIG_MODULE_UNLOAD
1674 struct module_use *use;
1675
1676 mutex_lock(&module_mutex);
1677 list_for_each_entry(use, &mod->target_list, target_list)
1678 sysfs_remove_link(use->target->holders_dir, mod->name);
1679 mutex_unlock(&module_mutex);
1680#endif
1681}
1682
1683static int add_usage_links(struct module *mod)
1684{
1685 int ret = 0;
1686#ifdef CONFIG_MODULE_UNLOAD
1687 struct module_use *use;
1688
1689 mutex_lock(&module_mutex);
1690 list_for_each_entry(use, &mod->target_list, target_list) {
1691 ret = sysfs_create_link(use->target->holders_dir,
1692 &mod->mkobj.kobj, mod->name);
1693 if (ret)
1694 break;
1695 }
1696 mutex_unlock(&module_mutex);
1697 if (ret)
1698 del_usage_links(mod);
1699#endif
1700 return ret;
1701}
1702
1703static int module_add_modinfo_attrs(struct module *mod)
1704{
1705 struct module_attribute *attr;
1706 struct module_attribute *temp_attr;
1707 int error = 0;
1708 int i;
1709
1710 mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
1711 (ARRAY_SIZE(modinfo_attrs) + 1)),
1712 GFP_KERNEL);
1713 if (!mod->modinfo_attrs)
1714 return -ENOMEM;
1715
1716 temp_attr = mod->modinfo_attrs;
1717 for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
1718 if (!attr->test || attr->test(mod)) {
1719 memcpy(temp_attr, attr, sizeof(*temp_attr));
1720 sysfs_attr_init(&temp_attr->attr);
1721 error = sysfs_create_file(&mod->mkobj.kobj,
1722 &temp_attr->attr);
1723 ++temp_attr;
1724 }
1725 }
1726 return error;
1727}
1728
1729static void module_remove_modinfo_attrs(struct module *mod)
1730{
1731 struct module_attribute *attr;
1732 int i;
1733
1734 for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
1735 /* pick a field to test for end of list */
1736 if (!attr->attr.name)
1737 break;
1738 sysfs_remove_file(&mod->mkobj.kobj, &attr->attr);
1739 if (attr->free)
1740 attr->free(mod);
1741 }
1742 kfree(mod->modinfo_attrs);
1743}
1744
1745static void mod_kobject_put(struct module *mod)
1746{
1747 DECLARE_COMPLETION_ONSTACK(c);
1748 mod->mkobj.kobj_completion = &c;
1749 kobject_put(&mod->mkobj.kobj);
1750 wait_for_completion(&c);
1751}
1752
1753static int mod_sysfs_init(struct module *mod)
1754{
1755 int err;
1756 struct kobject *kobj;
1757
1758 if (!module_sysfs_initialized) {
1759 pr_err("%s: module sysfs not initialized\n", mod->name);
1760 err = -EINVAL;
1761 goto out;
1762 }
1763
1764 kobj = kset_find_obj(module_kset, mod->name);
1765 if (kobj) {
1766 pr_err("%s: module is already loaded\n", mod->name);
1767 kobject_put(kobj);
1768 err = -EINVAL;
1769 goto out;
1770 }
1771
1772 mod->mkobj.mod = mod;
1773
1774 memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
1775 mod->mkobj.kobj.kset = module_kset;
1776 err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
1777 "%s", mod->name);
1778 if (err)
1779 mod_kobject_put(mod);
1780
1781 /* delay uevent until full sysfs population */
1782out:
1783 return err;
1784}
1785
1786static int mod_sysfs_setup(struct module *mod,
1787 const struct load_info *info,
1788 struct kernel_param *kparam,
1789 unsigned int num_params)
1790{
1791 int err;
1792
1793 err = mod_sysfs_init(mod);
1794 if (err)
1795 goto out;
1796
1797 mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1798 if (!mod->holders_dir) {
1799 err = -ENOMEM;
1800 goto out_unreg;
1801 }
1802
1803 err = module_param_sysfs_setup(mod, kparam, num_params);
1804 if (err)
1805 goto out_unreg_holders;
1806
1807 err = module_add_modinfo_attrs(mod);
1808 if (err)
1809 goto out_unreg_param;
1810
1811 err = add_usage_links(mod);
1812 if (err)
1813 goto out_unreg_modinfo_attrs;
1814
1815 add_sect_attrs(mod, info);
1816 add_notes_attrs(mod, info);
1817
1818 kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
1819 return 0;
1820
1821out_unreg_modinfo_attrs:
1822 module_remove_modinfo_attrs(mod);
1823out_unreg_param:
1824 module_param_sysfs_remove(mod);
1825out_unreg_holders:
1826 kobject_put(mod->holders_dir);
1827out_unreg:
1828 mod_kobject_put(mod);
1829out:
1830 return err;
1831}
1832
1833static void mod_sysfs_fini(struct module *mod)
1834{
1835 remove_notes_attrs(mod);
1836 remove_sect_attrs(mod);
1837 mod_kobject_put(mod);
1838}
1839
1840static void init_param_lock(struct module *mod)
1841{
1842 mutex_init(&mod->param_lock);
1843}
1844#else /* !CONFIG_SYSFS */
1845
1846static int mod_sysfs_setup(struct module *mod,
1847 const struct load_info *info,
1848 struct kernel_param *kparam,
1849 unsigned int num_params)
1850{
1851 return 0;
1852}
1853
1854static void mod_sysfs_fini(struct module *mod)
1855{
1856}
1857
1858static void module_remove_modinfo_attrs(struct module *mod)
1859{
1860}
1861
1862static void del_usage_links(struct module *mod)
1863{
1864}
1865
1866static void init_param_lock(struct module *mod)
1867{
1868}
1869#endif /* CONFIG_SYSFS */
1870
1871static void mod_sysfs_teardown(struct module *mod)
1872{
1873 del_usage_links(mod);
1874 module_remove_modinfo_attrs(mod);
1875 module_param_sysfs_remove(mod);
1876 kobject_put(mod->mkobj.drivers_dir);
1877 kobject_put(mod->holders_dir);
1878 mod_sysfs_fini(mod);
1879}
1880
1881#ifdef CONFIG_STRICT_MODULE_RWX
1882/*
1883 * LKM RO/NX protection: protect module's text/ro-data
1884 * from modification and any data from execution.
1885 *
1886 * General layout of module is:
1887 * [text] [read-only-data] [ro-after-init] [writable data]
1888 * text_size -----^ ^ ^ ^
1889 * ro_size ------------------------| | |
1890 * ro_after_init_size -----------------------------| |
1891 * size -----------------------------------------------------------|
1892 *
1893 * These values are always page-aligned (as is base)
1894 */
1895static void frob_text(const struct module_layout *layout,
1896 int (*set_memory)(unsigned long start, int num_pages))
1897{
1898 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1899 BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
1900 set_memory((unsigned long)layout->base,
1901 layout->text_size >> PAGE_SHIFT);
1902}
1903
1904static void frob_rodata(const struct module_layout *layout,
1905 int (*set_memory)(unsigned long start, int num_pages))
1906{
1907 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1908 BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
1909 BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
1910 set_memory((unsigned long)layout->base + layout->text_size,
1911 (layout->ro_size - layout->text_size) >> PAGE_SHIFT);
1912}
1913
1914static void frob_ro_after_init(const struct module_layout *layout,
1915 int (*set_memory)(unsigned long start, int num_pages))
1916{
1917 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1918 BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
1919 BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
1920 set_memory((unsigned long)layout->base + layout->ro_size,
1921 (layout->ro_after_init_size - layout->ro_size) >> PAGE_SHIFT);
1922}
1923
1924static void frob_writable_data(const struct module_layout *layout,
1925 int (*set_memory)(unsigned long start, int num_pages))
1926{
1927 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1928 BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
1929 BUG_ON((unsigned long)layout->size & (PAGE_SIZE-1));
1930 set_memory((unsigned long)layout->base + layout->ro_after_init_size,
1931 (layout->size - layout->ro_after_init_size) >> PAGE_SHIFT);
1932}
1933
1934/* livepatching wants to disable read-only so it can frob module. */
1935void module_disable_ro(const struct module *mod)
1936{
1937 if (!rodata_enabled)
1938 return;
1939
1940 frob_text(&mod->core_layout, set_memory_rw);
1941 frob_rodata(&mod->core_layout, set_memory_rw);
1942 frob_ro_after_init(&mod->core_layout, set_memory_rw);
1943 frob_text(&mod->init_layout, set_memory_rw);
1944 frob_rodata(&mod->init_layout, set_memory_rw);
1945}
1946
1947void module_enable_ro(const struct module *mod, bool after_init)
1948{
1949 if (!rodata_enabled)
1950 return;
1951
1952 frob_text(&mod->core_layout, set_memory_ro);
1953 frob_rodata(&mod->core_layout, set_memory_ro);
1954 frob_text(&mod->init_layout, set_memory_ro);
1955 frob_rodata(&mod->init_layout, set_memory_ro);
1956
1957 if (after_init)
1958 frob_ro_after_init(&mod->core_layout, set_memory_ro);
1959}
1960
1961static void module_enable_nx(const struct module *mod)
1962{
1963 frob_rodata(&mod->core_layout, set_memory_nx);
1964 frob_ro_after_init(&mod->core_layout, set_memory_nx);
1965 frob_writable_data(&mod->core_layout, set_memory_nx);
1966 frob_rodata(&mod->init_layout, set_memory_nx);
1967 frob_writable_data(&mod->init_layout, set_memory_nx);
1968}
1969
1970static void module_disable_nx(const struct module *mod)
1971{
1972 frob_rodata(&mod->core_layout, set_memory_x);
1973 frob_ro_after_init(&mod->core_layout, set_memory_x);
1974 frob_writable_data(&mod->core_layout, set_memory_x);
1975 frob_rodata(&mod->init_layout, set_memory_x);
1976 frob_writable_data(&mod->init_layout, set_memory_x);
1977}
1978
1979/* Iterate through all modules and set each module's text as RW */
1980void set_all_modules_text_rw(void)
1981{
1982 struct module *mod;
1983
1984 if (!rodata_enabled)
1985 return;
1986
1987 mutex_lock(&module_mutex);
1988 list_for_each_entry_rcu(mod, &modules, list) {
1989 if (mod->state == MODULE_STATE_UNFORMED)
1990 continue;
1991
1992 frob_text(&mod->core_layout, set_memory_rw);
1993 frob_text(&mod->init_layout, set_memory_rw);
1994 }
1995 mutex_unlock(&module_mutex);
1996}
1997
1998/* Iterate through all modules and set each module's text as RO */
1999void set_all_modules_text_ro(void)
2000{
2001 struct module *mod;
2002
2003 if (!rodata_enabled)
2004 return;
2005
2006 mutex_lock(&module_mutex);
2007 list_for_each_entry_rcu(mod, &modules, list) {
2008 /*
2009 * Ignore going modules since it's possible that ro
2010 * protection has already been disabled, otherwise we'll
2011 * run into protection faults at module deallocation.
2012 */
2013 if (mod->state == MODULE_STATE_UNFORMED ||
2014 mod->state == MODULE_STATE_GOING)
2015 continue;
2016
2017 frob_text(&mod->core_layout, set_memory_ro);
2018 frob_text(&mod->init_layout, set_memory_ro);
2019 }
2020 mutex_unlock(&module_mutex);
2021}
2022
2023static void disable_ro_nx(const struct module_layout *layout)
2024{
2025 if (rodata_enabled) {
2026 frob_text(layout, set_memory_rw);
2027 frob_rodata(layout, set_memory_rw);
2028 frob_ro_after_init(layout, set_memory_rw);
2029 }
2030 frob_rodata(layout, set_memory_x);
2031 frob_ro_after_init(layout, set_memory_x);
2032 frob_writable_data(layout, set_memory_x);
2033}
2034
2035#else
2036static void disable_ro_nx(const struct module_layout *layout) { }
2037static void module_enable_nx(const struct module *mod) { }
2038static void module_disable_nx(const struct module *mod) { }
2039#endif
2040
2041#ifdef CONFIG_LIVEPATCH
2042/*
2043 * Persist Elf information about a module. Copy the Elf header,
2044 * section header table, section string table, and symtab section
2045 * index from info to mod->klp_info.
2046 */
2047static int copy_module_elf(struct module *mod, struct load_info *info)
2048{
2049 unsigned int size, symndx;
2050 int ret;
2051
2052 size = sizeof(*mod->klp_info);
2053 mod->klp_info = kmalloc(size, GFP_KERNEL);
2054 if (mod->klp_info == NULL)
2055 return -ENOMEM;
2056
2057 /* Elf header */
2058 size = sizeof(mod->klp_info->hdr);
2059 memcpy(&mod->klp_info->hdr, info->hdr, size);
2060
2061 /* Elf section header table */
2062 size = sizeof(*info->sechdrs) * info->hdr->e_shnum;
2063 mod->klp_info->sechdrs = kmemdup(info->sechdrs, size, GFP_KERNEL);
2064 if (mod->klp_info->sechdrs == NULL) {
2065 ret = -ENOMEM;
2066 goto free_info;
2067 }
2068
2069 /* Elf section name string table */
2070 size = info->sechdrs[info->hdr->e_shstrndx].sh_size;
2071 mod->klp_info->secstrings = kmemdup(info->secstrings, size, GFP_KERNEL);
2072 if (mod->klp_info->secstrings == NULL) {
2073 ret = -ENOMEM;
2074 goto free_sechdrs;
2075 }
2076
2077 /* Elf symbol section index */
2078 symndx = info->index.sym;
2079 mod->klp_info->symndx = symndx;
2080
2081 /*
2082 * For livepatch modules, core_kallsyms.symtab is a complete
2083 * copy of the original symbol table. Adjust sh_addr to point
2084 * to core_kallsyms.symtab since the copy of the symtab in module
2085 * init memory is freed at the end of do_init_module().
2086 */
2087 mod->klp_info->sechdrs[symndx].sh_addr = \
2088 (unsigned long) mod->core_kallsyms.symtab;
2089
2090 return 0;
2091
2092free_sechdrs:
2093 kfree(mod->klp_info->sechdrs);
2094free_info:
2095 kfree(mod->klp_info);
2096 return ret;
2097}
2098
2099static void free_module_elf(struct module *mod)
2100{
2101 kfree(mod->klp_info->sechdrs);
2102 kfree(mod->klp_info->secstrings);
2103 kfree(mod->klp_info);
2104}
2105#else /* !CONFIG_LIVEPATCH */
2106static int copy_module_elf(struct module *mod, struct load_info *info)
2107{
2108 return 0;
2109}
2110
2111static void free_module_elf(struct module *mod)
2112{
2113}
2114#endif /* CONFIG_LIVEPATCH */
2115
2116void __weak module_memfree(void *module_region)
2117{
2118 vfree(module_region);
2119}
2120
2121void __weak module_arch_cleanup(struct module *mod)
2122{
2123}
2124
2125void __weak module_arch_freeing_init(struct module *mod)
2126{
2127}
2128
2129/* Free a module, remove from lists, etc. */
2130static void free_module(struct module *mod)
2131{
2132 trace_module_free(mod);
2133
2134 mod_sysfs_teardown(mod);
2135
2136 /* We leave it in list to prevent duplicate loads, but make sure
2137 * that noone uses it while it's being deconstructed. */
2138 mutex_lock(&module_mutex);
2139 mod->state = MODULE_STATE_UNFORMED;
2140 mutex_unlock(&module_mutex);
2141
2142 /* Remove dynamic debug info */
2143 ddebug_remove_module(mod->name);
2144
2145 /* Arch-specific cleanup. */
2146 module_arch_cleanup(mod);
2147
2148 /* Module unload stuff */
2149 module_unload_free(mod);
2150
2151 /* Free any allocated parameters. */
2152 destroy_params(mod->kp, mod->num_kp);
2153
2154 if (is_livepatch_module(mod))
2155 free_module_elf(mod);
2156
2157 /* Now we can delete it from the lists */
2158 mutex_lock(&module_mutex);
2159 /* Unlink carefully: kallsyms could be walking list. */
2160 list_del_rcu(&mod->list);
2161 mod_tree_remove(mod);
2162 /* Remove this module from bug list, this uses list_del_rcu */
2163 module_bug_cleanup(mod);
2164 /* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */
2165 synchronize_rcu();
2166 mutex_unlock(&module_mutex);
2167
2168 /* This may be empty, but that's OK */
2169 disable_ro_nx(&mod->init_layout);
2170 module_arch_freeing_init(mod);
2171 module_memfree(mod->init_layout.base);
2172 kfree(mod->args);
2173 percpu_modfree(mod);
2174
2175 /* Free lock-classes; relies on the preceding sync_rcu(). */
2176 lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
2177
2178 /* Finally, free the core (containing the module structure) */
2179 disable_ro_nx(&mod->core_layout);
2180 module_memfree(mod->core_layout.base);
2181}
2182
2183void *__symbol_get(const char *symbol)
2184{
2185 struct module *owner;
2186 const struct kernel_symbol *sym;
2187
2188 preempt_disable();
2189 sym = find_symbol(symbol, &owner, NULL, true, true);
2190 if (sym && strong_try_module_get(owner))
2191 sym = NULL;
2192 preempt_enable();
2193
2194 return sym ? (void *)kernel_symbol_value(sym) : NULL;
2195}
2196EXPORT_SYMBOL_GPL(__symbol_get);
2197
2198/*
2199 * Ensure that an exported symbol [global namespace] does not already exist
2200 * in the kernel or in some other module's exported symbol table.
2201 *
2202 * You must hold the module_mutex.
2203 */
2204static int verify_exported_symbols(struct module *mod)
2205{
2206 unsigned int i;
2207 struct module *owner;
2208 const struct kernel_symbol *s;
2209 struct {
2210 const struct kernel_symbol *sym;
2211 unsigned int num;
2212 } arr[] = {
2213 { mod->syms, mod->num_syms },
2214 { mod->gpl_syms, mod->num_gpl_syms },
2215 { mod->gpl_future_syms, mod->num_gpl_future_syms },
2216#ifdef CONFIG_UNUSED_SYMBOLS
2217 { mod->unused_syms, mod->num_unused_syms },
2218 { mod->unused_gpl_syms, mod->num_unused_gpl_syms },
2219#endif
2220 };
2221
2222 for (i = 0; i < ARRAY_SIZE(arr); i++) {
2223 for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
2224 if (find_symbol(kernel_symbol_name(s), &owner, NULL,
2225 true, false)) {
2226 pr_err("%s: exports duplicate symbol %s"
2227 " (owned by %s)\n",
2228 mod->name, kernel_symbol_name(s),
2229 module_name(owner));
2230 return -ENOEXEC;
2231 }
2232 }
2233 }
2234 return 0;
2235}
2236
2237/* Change all symbols so that st_value encodes the pointer directly. */
2238static int simplify_symbols(struct module *mod, const struct load_info *info)
2239{
2240 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2241 Elf_Sym *sym = (void *)symsec->sh_addr;
2242 unsigned long secbase;
2243 unsigned int i;
2244 int ret = 0;
2245 const struct kernel_symbol *ksym;
2246
2247 for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
2248 const char *name = info->strtab + sym[i].st_name;
2249
2250 switch (sym[i].st_shndx) {
2251 case SHN_COMMON:
2252 /* Ignore common symbols */
2253 if (!strncmp(name, "__gnu_lto", 9))
2254 break;
2255
2256 /* We compiled with -fno-common. These are not
2257 supposed to happen. */
2258 pr_debug("Common symbol: %s\n", name);
2259 pr_warn("%s: please compile with -fno-common\n",
2260 mod->name);
2261 ret = -ENOEXEC;
2262 break;
2263
2264 case SHN_ABS:
2265 /* Don't need to do anything */
2266 pr_debug("Absolute symbol: 0x%08lx\n",
2267 (long)sym[i].st_value);
2268 break;
2269
2270 case SHN_LIVEPATCH:
2271 /* Livepatch symbols are resolved by livepatch */
2272 break;
2273
2274 case SHN_UNDEF:
2275 ksym = resolve_symbol_wait(mod, info, name);
2276 /* Ok if resolved. */
2277 if (ksym && !IS_ERR(ksym)) {
2278 sym[i].st_value = kernel_symbol_value(ksym);
2279 break;
2280 }
2281
2282 /* Ok if weak. */
2283 if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
2284 break;
2285
2286 ret = PTR_ERR(ksym) ?: -ENOENT;
2287 pr_warn("%s: Unknown symbol %s (err %d)\n",
2288 mod->name, name, ret);
2289 break;
2290
2291 default:
2292 /* Divert to percpu allocation if a percpu var. */
2293 if (sym[i].st_shndx == info->index.pcpu)
2294 secbase = (unsigned long)mod_percpu(mod);
2295 else
2296 secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
2297 sym[i].st_value += secbase;
2298 break;
2299 }
2300 }
2301
2302 return ret;
2303}
2304
2305static int apply_relocations(struct module *mod, const struct load_info *info)
2306{
2307 unsigned int i;
2308 int err = 0;
2309
2310 /* Now do relocations. */
2311 for (i = 1; i < info->hdr->e_shnum; i++) {
2312 unsigned int infosec = info->sechdrs[i].sh_info;
2313
2314 /* Not a valid relocation section? */
2315 if (infosec >= info->hdr->e_shnum)
2316 continue;
2317
2318 /* Don't bother with non-allocated sections */
2319 if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
2320 continue;
2321
2322 /* Livepatch relocation sections are applied by livepatch */
2323 if (info->sechdrs[i].sh_flags & SHF_RELA_LIVEPATCH)
2324 continue;
2325
2326 if (info->sechdrs[i].sh_type == SHT_REL)
2327 err = apply_relocate(info->sechdrs, info->strtab,
2328 info->index.sym, i, mod);
2329 else if (info->sechdrs[i].sh_type == SHT_RELA)
2330 err = apply_relocate_add(info->sechdrs, info->strtab,
2331 info->index.sym, i, mod);
2332 if (err < 0)
2333 break;
2334 }
2335 return err;
2336}
2337
2338/* Additional bytes needed by arch in front of individual sections */
2339unsigned int __weak arch_mod_section_prepend(struct module *mod,
2340 unsigned int section)
2341{
2342 /* default implementation just returns zero */
2343 return 0;
2344}
2345
2346/* Update size with this section: return offset. */
2347static long get_offset(struct module *mod, unsigned int *size,
2348 Elf_Shdr *sechdr, unsigned int section)
2349{
2350 long ret;
2351
2352 *size += arch_mod_section_prepend(mod, section);
2353 ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
2354 *size = ret + sechdr->sh_size;
2355 return ret;
2356}
2357
2358/* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
2359 might -- code, read-only data, read-write data, small data. Tally
2360 sizes, and place the offsets into sh_entsize fields: high bit means it
2361 belongs in init. */
2362static void layout_sections(struct module *mod, struct load_info *info)
2363{
2364 static unsigned long const masks[][2] = {
2365 /* NOTE: all executable code must be the first section
2366 * in this array; otherwise modify the text_size
2367 * finder in the two loops below */
2368 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
2369 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
2370 { SHF_RO_AFTER_INIT | SHF_ALLOC, ARCH_SHF_SMALL },
2371 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
2372 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
2373 };
2374 unsigned int m, i;
2375
2376 for (i = 0; i < info->hdr->e_shnum; i++)
2377 info->sechdrs[i].sh_entsize = ~0UL;
2378
2379 pr_debug("Core section allocation order:\n");
2380 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2381 for (i = 0; i < info->hdr->e_shnum; ++i) {
2382 Elf_Shdr *s = &info->sechdrs[i];
2383 const char *sname = info->secstrings + s->sh_name;
2384
2385 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2386 || (s->sh_flags & masks[m][1])
2387 || s->sh_entsize != ~0UL
2388 || strstarts(sname, ".init"))
2389 continue;
2390 s->sh_entsize = get_offset(mod, &mod->core_layout.size, s, i);
2391 pr_debug("\t%s\n", sname);
2392 }
2393 switch (m) {
2394 case 0: /* executable */
2395 mod->core_layout.size = debug_align(mod->core_layout.size);
2396 mod->core_layout.text_size = mod->core_layout.size;
2397 break;
2398 case 1: /* RO: text and ro-data */
2399 mod->core_layout.size = debug_align(mod->core_layout.size);
2400 mod->core_layout.ro_size = mod->core_layout.size;
2401 break;
2402 case 2: /* RO after init */
2403 mod->core_layout.size = debug_align(mod->core_layout.size);
2404 mod->core_layout.ro_after_init_size = mod->core_layout.size;
2405 break;
2406 case 4: /* whole core */
2407 mod->core_layout.size = debug_align(mod->core_layout.size);
2408 break;
2409 }
2410 }
2411
2412 pr_debug("Init section allocation order:\n");
2413 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2414 for (i = 0; i < info->hdr->e_shnum; ++i) {
2415 Elf_Shdr *s = &info->sechdrs[i];
2416 const char *sname = info->secstrings + s->sh_name;
2417
2418 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2419 || (s->sh_flags & masks[m][1])
2420 || s->sh_entsize != ~0UL
2421 || !strstarts(sname, ".init"))
2422 continue;
2423 s->sh_entsize = (get_offset(mod, &mod->init_layout.size, s, i)
2424 | INIT_OFFSET_MASK);
2425 pr_debug("\t%s\n", sname);
2426 }
2427 switch (m) {
2428 case 0: /* executable */
2429 mod->init_layout.size = debug_align(mod->init_layout.size);
2430 mod->init_layout.text_size = mod->init_layout.size;
2431 break;
2432 case 1: /* RO: text and ro-data */
2433 mod->init_layout.size = debug_align(mod->init_layout.size);
2434 mod->init_layout.ro_size = mod->init_layout.size;
2435 break;
2436 case 2:
2437 /*
2438 * RO after init doesn't apply to init_layout (only
2439 * core_layout), so it just takes the value of ro_size.
2440 */
2441 mod->init_layout.ro_after_init_size = mod->init_layout.ro_size;
2442 break;
2443 case 4: /* whole init */
2444 mod->init_layout.size = debug_align(mod->init_layout.size);
2445 break;
2446 }
2447 }
2448}
2449
2450static void set_license(struct module *mod, const char *license)
2451{
2452 if (!license)
2453 license = "unspecified";
2454
2455 if (!license_is_gpl_compatible(license)) {
2456 if (!test_taint(TAINT_PROPRIETARY_MODULE))
2457 pr_warn("%s: module license '%s' taints kernel.\n",
2458 mod->name, license);
2459 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2460 LOCKDEP_NOW_UNRELIABLE);
2461 }
2462}
2463
2464/* Parse tag=value strings from .modinfo section */
2465static char *next_string(char *string, unsigned long *secsize)
2466{
2467 /* Skip non-zero chars */
2468 while (string[0]) {
2469 string++;
2470 if ((*secsize)-- <= 1)
2471 return NULL;
2472 }
2473
2474 /* Skip any zero padding. */
2475 while (!string[0]) {
2476 string++;
2477 if ((*secsize)-- <= 1)
2478 return NULL;
2479 }
2480 return string;
2481}
2482
2483static char *get_modinfo(struct load_info *info, const char *tag)
2484{
2485 char *p;
2486 unsigned int taglen = strlen(tag);
2487 Elf_Shdr *infosec = &info->sechdrs[info->index.info];
2488 unsigned long size = infosec->sh_size;
2489
2490 /*
2491 * get_modinfo() calls made before rewrite_section_headers()
2492 * must use sh_offset, as sh_addr isn't set!
2493 */
2494 for (p = (char *)info->hdr + infosec->sh_offset; p; p = next_string(p, &size)) {
2495 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
2496 return p + taglen + 1;
2497 }
2498 return NULL;
2499}
2500
2501static void setup_modinfo(struct module *mod, struct load_info *info)
2502{
2503 struct module_attribute *attr;
2504 int i;
2505
2506 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2507 if (attr->setup)
2508 attr->setup(mod, get_modinfo(info, attr->attr.name));
2509 }
2510}
2511
2512static void free_modinfo(struct module *mod)
2513{
2514 struct module_attribute *attr;
2515 int i;
2516
2517 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2518 if (attr->free)
2519 attr->free(mod);
2520 }
2521}
2522
2523#ifdef CONFIG_KALLSYMS
2524
2525/* Lookup exported symbol in given range of kernel_symbols */
2526static const struct kernel_symbol *lookup_exported_symbol(const char *name,
2527 const struct kernel_symbol *start,
2528 const struct kernel_symbol *stop)
2529{
2530 return bsearch(name, start, stop - start,
2531 sizeof(struct kernel_symbol), cmp_name);
2532}
2533
2534static int is_exported(const char *name, unsigned long value,
2535 const struct module *mod)
2536{
2537 const struct kernel_symbol *ks;
2538 if (!mod)
2539 ks = lookup_exported_symbol(name, __start___ksymtab, __stop___ksymtab);
2540 else
2541 ks = lookup_exported_symbol(name, mod->syms, mod->syms + mod->num_syms);
2542
2543 return ks != NULL && kernel_symbol_value(ks) == value;
2544}
2545
2546/* As per nm */
2547static char elf_type(const Elf_Sym *sym, const struct load_info *info)
2548{
2549 const Elf_Shdr *sechdrs = info->sechdrs;
2550
2551 if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
2552 if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
2553 return 'v';
2554 else
2555 return 'w';
2556 }
2557 if (sym->st_shndx == SHN_UNDEF)
2558 return 'U';
2559 if (sym->st_shndx == SHN_ABS || sym->st_shndx == info->index.pcpu)
2560 return 'a';
2561 if (sym->st_shndx >= SHN_LORESERVE)
2562 return '?';
2563 if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
2564 return 't';
2565 if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
2566 && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
2567 if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
2568 return 'r';
2569 else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2570 return 'g';
2571 else
2572 return 'd';
2573 }
2574 if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
2575 if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2576 return 's';
2577 else
2578 return 'b';
2579 }
2580 if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
2581 ".debug")) {
2582 return 'n';
2583 }
2584 return '?';
2585}
2586
2587static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
2588 unsigned int shnum, unsigned int pcpundx)
2589{
2590 const Elf_Shdr *sec;
2591
2592 if (src->st_shndx == SHN_UNDEF
2593 || src->st_shndx >= shnum
2594 || !src->st_name)
2595 return false;
2596
2597#ifdef CONFIG_KALLSYMS_ALL
2598 if (src->st_shndx == pcpundx)
2599 return true;
2600#endif
2601
2602 sec = sechdrs + src->st_shndx;
2603 if (!(sec->sh_flags & SHF_ALLOC)
2604#ifndef CONFIG_KALLSYMS_ALL
2605 || !(sec->sh_flags & SHF_EXECINSTR)
2606#endif
2607 || (sec->sh_entsize & INIT_OFFSET_MASK))
2608 return false;
2609
2610 return true;
2611}
2612
2613/*
2614 * We only allocate and copy the strings needed by the parts of symtab
2615 * we keep. This is simple, but has the effect of making multiple
2616 * copies of duplicates. We could be more sophisticated, see
2617 * linux-kernel thread starting with
2618 * <73defb5e4bca04a6431392cc341112b1@localhost>.
2619 */
2620static void layout_symtab(struct module *mod, struct load_info *info)
2621{
2622 Elf_Shdr *symsect = info->sechdrs + info->index.sym;
2623 Elf_Shdr *strsect = info->sechdrs + info->index.str;
2624 const Elf_Sym *src;
2625 unsigned int i, nsrc, ndst, strtab_size = 0;
2626
2627 /* Put symbol section at end of init part of module. */
2628 symsect->sh_flags |= SHF_ALLOC;
2629 symsect->sh_entsize = get_offset(mod, &mod->init_layout.size, symsect,
2630 info->index.sym) | INIT_OFFSET_MASK;
2631 pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
2632
2633 src = (void *)info->hdr + symsect->sh_offset;
2634 nsrc = symsect->sh_size / sizeof(*src);
2635
2636 /* Compute total space required for the core symbols' strtab. */
2637 for (ndst = i = 0; i < nsrc; i++) {
2638 if (i == 0 || is_livepatch_module(mod) ||
2639 is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
2640 info->index.pcpu)) {
2641 strtab_size += strlen(&info->strtab[src[i].st_name])+1;
2642 ndst++;
2643 }
2644 }
2645
2646 /* Append room for core symbols at end of core part. */
2647 info->symoffs = ALIGN(mod->core_layout.size, symsect->sh_addralign ?: 1);
2648 info->stroffs = mod->core_layout.size = info->symoffs + ndst * sizeof(Elf_Sym);
2649 mod->core_layout.size += strtab_size;
2650 mod->core_layout.size = debug_align(mod->core_layout.size);
2651
2652 /* Put string table section at end of init part of module. */
2653 strsect->sh_flags |= SHF_ALLOC;
2654 strsect->sh_entsize = get_offset(mod, &mod->init_layout.size, strsect,
2655 info->index.str) | INIT_OFFSET_MASK;
2656 pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
2657
2658 /* We'll tack temporary mod_kallsyms on the end. */
2659 mod->init_layout.size = ALIGN(mod->init_layout.size,
2660 __alignof__(struct mod_kallsyms));
2661 info->mod_kallsyms_init_off = mod->init_layout.size;
2662 mod->init_layout.size += sizeof(struct mod_kallsyms);
2663 mod->init_layout.size = debug_align(mod->init_layout.size);
2664}
2665
2666/*
2667 * We use the full symtab and strtab which layout_symtab arranged to
2668 * be appended to the init section. Later we switch to the cut-down
2669 * core-only ones.
2670 */
2671static void add_kallsyms(struct module *mod, const struct load_info *info)
2672{
2673 unsigned int i, ndst;
2674 const Elf_Sym *src;
2675 Elf_Sym *dst;
2676 char *s;
2677 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2678
2679 /* Set up to point into init section. */
2680 mod->kallsyms = mod->init_layout.base + info->mod_kallsyms_init_off;
2681
2682 mod->kallsyms->symtab = (void *)symsec->sh_addr;
2683 mod->kallsyms->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
2684 /* Make sure we get permanent strtab: don't use info->strtab. */
2685 mod->kallsyms->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
2686
2687 /* Set types up while we still have access to sections. */
2688 for (i = 0; i < mod->kallsyms->num_symtab; i++)
2689 mod->kallsyms->symtab[i].st_size
2690 = elf_type(&mod->kallsyms->symtab[i], info);
2691
2692 /* Now populate the cut down core kallsyms for after init. */
2693 mod->core_kallsyms.symtab = dst = mod->core_layout.base + info->symoffs;
2694 mod->core_kallsyms.strtab = s = mod->core_layout.base + info->stroffs;
2695 src = mod->kallsyms->symtab;
2696 for (ndst = i = 0; i < mod->kallsyms->num_symtab; i++) {
2697 if (i == 0 || is_livepatch_module(mod) ||
2698 is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
2699 info->index.pcpu)) {
2700 dst[ndst] = src[i];
2701 dst[ndst++].st_name = s - mod->core_kallsyms.strtab;
2702 s += strlcpy(s, &mod->kallsyms->strtab[src[i].st_name],
2703 KSYM_NAME_LEN) + 1;
2704 }
2705 }
2706 mod->core_kallsyms.num_symtab = ndst;
2707}
2708#else
2709static inline void layout_symtab(struct module *mod, struct load_info *info)
2710{
2711}
2712
2713static void add_kallsyms(struct module *mod, const struct load_info *info)
2714{
2715}
2716#endif /* CONFIG_KALLSYMS */
2717
2718static void dynamic_debug_setup(struct module *mod, struct _ddebug *debug, unsigned int num)
2719{
2720 if (!debug)
2721 return;
2722 ddebug_add_module(debug, num, mod->name);
2723}
2724
2725static void dynamic_debug_remove(struct module *mod, struct _ddebug *debug)
2726{
2727 if (debug)
2728 ddebug_remove_module(mod->name);
2729}
2730
2731void * __weak module_alloc(unsigned long size)
2732{
2733 return vmalloc_exec(size);
2734}
2735
2736#ifdef CONFIG_DEBUG_KMEMLEAK
2737static void kmemleak_load_module(const struct module *mod,
2738 const struct load_info *info)
2739{
2740 unsigned int i;
2741
2742 /* only scan the sections containing data */
2743 kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
2744
2745 for (i = 1; i < info->hdr->e_shnum; i++) {
2746 /* Scan all writable sections that's not executable */
2747 if (!(info->sechdrs[i].sh_flags & SHF_ALLOC) ||
2748 !(info->sechdrs[i].sh_flags & SHF_WRITE) ||
2749 (info->sechdrs[i].sh_flags & SHF_EXECINSTR))
2750 continue;
2751
2752 kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
2753 info->sechdrs[i].sh_size, GFP_KERNEL);
2754 }
2755}
2756#else
2757static inline void kmemleak_load_module(const struct module *mod,
2758 const struct load_info *info)
2759{
2760}
2761#endif
2762
2763#ifdef CONFIG_MODULE_SIG
2764static int module_sig_check(struct load_info *info, int flags)
2765{
2766 int err = -ENOKEY;
2767 const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
2768 const void *mod = info->hdr;
2769
2770 /*
2771 * Require flags == 0, as a module with version information
2772 * removed is no longer the module that was signed
2773 */
2774 if (flags == 0 &&
2775 info->len > markerlen &&
2776 memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
2777 /* We truncate the module to discard the signature */
2778 info->len -= markerlen;
2779 err = mod_verify_sig(mod, info);
2780 }
2781
2782 if (!err) {
2783 info->sig_ok = true;
2784 return 0;
2785 }
2786
2787 /* Not having a signature is only an error if we're strict. */
2788 if (err == -ENOKEY && !is_module_sig_enforced())
2789 err = 0;
2790
2791 return err;
2792}
2793#else /* !CONFIG_MODULE_SIG */
2794static int module_sig_check(struct load_info *info, int flags)
2795{
2796 return 0;
2797}
2798#endif /* !CONFIG_MODULE_SIG */
2799
2800/* Sanity checks against invalid binaries, wrong arch, weird elf version. */
2801static int elf_header_check(struct load_info *info)
2802{
2803 if (info->len < sizeof(*(info->hdr)))
2804 return -ENOEXEC;
2805
2806 if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0
2807 || info->hdr->e_type != ET_REL
2808 || !elf_check_arch(info->hdr)
2809 || info->hdr->e_shentsize != sizeof(Elf_Shdr))
2810 return -ENOEXEC;
2811
2812 if (info->hdr->e_shoff >= info->len
2813 || (info->hdr->e_shnum * sizeof(Elf_Shdr) >
2814 info->len - info->hdr->e_shoff))
2815 return -ENOEXEC;
2816
2817 return 0;
2818}
2819
2820#define COPY_CHUNK_SIZE (16*PAGE_SIZE)
2821
2822static int copy_chunked_from_user(void *dst, const void __user *usrc, unsigned long len)
2823{
2824 do {
2825 unsigned long n = min(len, COPY_CHUNK_SIZE);
2826
2827 if (copy_from_user(dst, usrc, n) != 0)
2828 return -EFAULT;
2829 cond_resched();
2830 dst += n;
2831 usrc += n;
2832 len -= n;
2833 } while (len);
2834 return 0;
2835}
2836
2837#ifdef CONFIG_LIVEPATCH
2838static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
2839{
2840 if (get_modinfo(info, "livepatch")) {
2841 mod->klp = true;
2842 add_taint_module(mod, TAINT_LIVEPATCH, LOCKDEP_STILL_OK);
2843 pr_notice_once("%s: tainting kernel with TAINT_LIVEPATCH\n",
2844 mod->name);
2845 }
2846
2847 return 0;
2848}
2849#else /* !CONFIG_LIVEPATCH */
2850static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
2851{
2852 if (get_modinfo(info, "livepatch")) {
2853 pr_err("%s: module is marked as livepatch module, but livepatch support is disabled",
2854 mod->name);
2855 return -ENOEXEC;
2856 }
2857
2858 return 0;
2859}
2860#endif /* CONFIG_LIVEPATCH */
2861
2862static void check_modinfo_retpoline(struct module *mod, struct load_info *info)
2863{
2864 if (retpoline_module_ok(get_modinfo(info, "retpoline")))
2865 return;
2866
2867 pr_warn("%s: loading module not compiled with retpoline compiler.\n",
2868 mod->name);
2869}
2870
2871/* Sets info->hdr and info->len. */
2872static int copy_module_from_user(const void __user *umod, unsigned long len,
2873 struct load_info *info)
2874{
2875 int err;
2876
2877 info->len = len;
2878 if (info->len < sizeof(*(info->hdr)))
2879 return -ENOEXEC;
2880
2881 err = security_kernel_load_data(LOADING_MODULE);
2882 if (err)
2883 return err;
2884
2885 /* Suck in entire file: we'll want most of it. */
2886 info->hdr = __vmalloc(info->len,
2887 GFP_KERNEL | __GFP_NOWARN, PAGE_KERNEL);
2888 if (!info->hdr)
2889 return -ENOMEM;
2890
2891 if (copy_chunked_from_user(info->hdr, umod, info->len) != 0) {
2892 vfree(info->hdr);
2893 return -EFAULT;
2894 }
2895
2896 return 0;
2897}
2898
2899static void free_copy(struct load_info *info)
2900{
2901 vfree(info->hdr);
2902}
2903
2904static int rewrite_section_headers(struct load_info *info, int flags)
2905{
2906 unsigned int i;
2907
2908 /* This should always be true, but let's be sure. */
2909 info->sechdrs[0].sh_addr = 0;
2910
2911 for (i = 1; i < info->hdr->e_shnum; i++) {
2912 Elf_Shdr *shdr = &info->sechdrs[i];
2913 if (shdr->sh_type != SHT_NOBITS
2914 && info->len < shdr->sh_offset + shdr->sh_size) {
2915 pr_err("Module len %lu truncated\n", info->len);
2916 return -ENOEXEC;
2917 }
2918
2919 /* Mark all sections sh_addr with their address in the
2920 temporary image. */
2921 shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
2922
2923#ifndef CONFIG_MODULE_UNLOAD
2924 /* Don't load .exit sections */
2925 if (strstarts(info->secstrings+shdr->sh_name, ".exit"))
2926 shdr->sh_flags &= ~(unsigned long)SHF_ALLOC;
2927#endif
2928 }
2929
2930 /* Track but don't keep modinfo and version sections. */
2931 info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
2932 info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
2933
2934 return 0;
2935}
2936
2937/*
2938 * Set up our basic convenience variables (pointers to section headers,
2939 * search for module section index etc), and do some basic section
2940 * verification.
2941 *
2942 * Set info->mod to the temporary copy of the module in info->hdr. The final one
2943 * will be allocated in move_module().
2944 */
2945static int setup_load_info(struct load_info *info, int flags)
2946{
2947 unsigned int i;
2948
2949 /* Set up the convenience variables */
2950 info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
2951 info->secstrings = (void *)info->hdr
2952 + info->sechdrs[info->hdr->e_shstrndx].sh_offset;
2953
2954 /* Try to find a name early so we can log errors with a module name */
2955 info->index.info = find_sec(info, ".modinfo");
2956 if (!info->index.info)
2957 info->name = "(missing .modinfo section)";
2958 else
2959 info->name = get_modinfo(info, "name");
2960
2961 /* Find internal symbols and strings. */
2962 for (i = 1; i < info->hdr->e_shnum; i++) {
2963 if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
2964 info->index.sym = i;
2965 info->index.str = info->sechdrs[i].sh_link;
2966 info->strtab = (char *)info->hdr
2967 + info->sechdrs[info->index.str].sh_offset;
2968 break;
2969 }
2970 }
2971
2972 if (info->index.sym == 0) {
2973 pr_warn("%s: module has no symbols (stripped?)\n", info->name);
2974 return -ENOEXEC;
2975 }
2976
2977 info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
2978 if (!info->index.mod) {
2979 pr_warn("%s: No module found in object\n",
2980 info->name ?: "(missing .modinfo name field)");
2981 return -ENOEXEC;
2982 }
2983 /* This is temporary: point mod into copy of data. */
2984 info->mod = (void *)info->hdr + info->sechdrs[info->index.mod].sh_offset;
2985
2986 /*
2987 * If we didn't load the .modinfo 'name' field earlier, fall back to
2988 * on-disk struct mod 'name' field.
2989 */
2990 if (!info->name)
2991 info->name = info->mod->name;
2992
2993 if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
2994 info->index.vers = 0; /* Pretend no __versions section! */
2995 else
2996 info->index.vers = find_sec(info, "__versions");
2997
2998 info->index.pcpu = find_pcpusec(info);
2999
3000 return 0;
3001}
3002
3003static int check_modinfo(struct module *mod, struct load_info *info, int flags)
3004{
3005 const char *modmagic = get_modinfo(info, "vermagic");
3006 int err;
3007
3008 if (flags & MODULE_INIT_IGNORE_VERMAGIC)
3009 modmagic = NULL;
3010
3011 /* This is allowed: modprobe --force will invalidate it. */
3012 if (!modmagic) {
3013 err = try_to_force_load(mod, "bad vermagic");
3014 if (err)
3015 return err;
3016 } else if (!same_magic(modmagic, vermagic, info->index.vers)) {
3017 pr_err("%s: version magic '%s' should be '%s'\n",
3018 info->name, modmagic, vermagic);
3019 return -ENOEXEC;
3020 }
3021
3022 if (!get_modinfo(info, "intree")) {
3023 if (!test_taint(TAINT_OOT_MODULE))
3024 pr_warn("%s: loading out-of-tree module taints kernel.\n",
3025 mod->name);
3026 add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
3027 }
3028
3029 check_modinfo_retpoline(mod, info);
3030
3031 if (get_modinfo(info, "staging")) {
3032 add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
3033 pr_warn("%s: module is from the staging directory, the quality "
3034 "is unknown, you have been warned.\n", mod->name);
3035 }
3036
3037 err = check_modinfo_livepatch(mod, info);
3038 if (err)
3039 return err;
3040
3041 /* Set up license info based on the info section */
3042 set_license(mod, get_modinfo(info, "license"));
3043
3044 return 0;
3045}
3046
3047static int find_module_sections(struct module *mod, struct load_info *info)
3048{
3049 mod->kp = section_objs(info, "__param",
3050 sizeof(*mod->kp), &mod->num_kp);
3051 mod->syms = section_objs(info, "__ksymtab",
3052 sizeof(*mod->syms), &mod->num_syms);
3053 mod->crcs = section_addr(info, "__kcrctab");
3054 mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
3055 sizeof(*mod->gpl_syms),
3056 &mod->num_gpl_syms);
3057 mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
3058 mod->gpl_future_syms = section_objs(info,
3059 "__ksymtab_gpl_future",
3060 sizeof(*mod->gpl_future_syms),
3061 &mod->num_gpl_future_syms);
3062 mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future");
3063
3064#ifdef CONFIG_UNUSED_SYMBOLS
3065 mod->unused_syms = section_objs(info, "__ksymtab_unused",
3066 sizeof(*mod->unused_syms),
3067 &mod->num_unused_syms);
3068 mod->unused_crcs = section_addr(info, "__kcrctab_unused");
3069 mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl",
3070 sizeof(*mod->unused_gpl_syms),
3071 &mod->num_unused_gpl_syms);
3072 mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl");
3073#endif
3074#ifdef CONFIG_CONSTRUCTORS
3075 mod->ctors = section_objs(info, ".ctors",
3076 sizeof(*mod->ctors), &mod->num_ctors);
3077 if (!mod->ctors)
3078 mod->ctors = section_objs(info, ".init_array",
3079 sizeof(*mod->ctors), &mod->num_ctors);
3080 else if (find_sec(info, ".init_array")) {
3081 /*
3082 * This shouldn't happen with same compiler and binutils
3083 * building all parts of the module.
3084 */
3085 pr_warn("%s: has both .ctors and .init_array.\n",
3086 mod->name);
3087 return -EINVAL;
3088 }
3089#endif
3090
3091#ifdef CONFIG_TRACEPOINTS
3092 mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
3093 sizeof(*mod->tracepoints_ptrs),
3094 &mod->num_tracepoints);
3095#endif
3096#ifdef CONFIG_BPF_EVENTS
3097 mod->bpf_raw_events = section_objs(info, "__bpf_raw_tp_map",
3098 sizeof(*mod->bpf_raw_events),
3099 &mod->num_bpf_raw_events);
3100#endif
3101#ifdef CONFIG_JUMP_LABEL
3102 mod->jump_entries = section_objs(info, "__jump_table",
3103 sizeof(*mod->jump_entries),
3104 &mod->num_jump_entries);
3105#endif
3106#ifdef CONFIG_EVENT_TRACING
3107 mod->trace_events = section_objs(info, "_ftrace_events",
3108 sizeof(*mod->trace_events),
3109 &mod->num_trace_events);
3110 mod->trace_evals = section_objs(info, "_ftrace_eval_map",
3111 sizeof(*mod->trace_evals),
3112 &mod->num_trace_evals);
3113#endif
3114#ifdef CONFIG_TRACING
3115 mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
3116 sizeof(*mod->trace_bprintk_fmt_start),
3117 &mod->num_trace_bprintk_fmt);
3118#endif
3119#ifdef CONFIG_FTRACE_MCOUNT_RECORD
3120 /* sechdrs[0].sh_size is always zero */
3121 mod->ftrace_callsites = section_objs(info, "__mcount_loc",
3122 sizeof(*mod->ftrace_callsites),
3123 &mod->num_ftrace_callsites);
3124#endif
3125#ifdef CONFIG_FUNCTION_ERROR_INJECTION
3126 mod->ei_funcs = section_objs(info, "_error_injection_whitelist",
3127 sizeof(*mod->ei_funcs),
3128 &mod->num_ei_funcs);
3129#endif
3130 mod->extable = section_objs(info, "__ex_table",
3131 sizeof(*mod->extable), &mod->num_exentries);
3132
3133 if (section_addr(info, "__obsparm"))
3134 pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
3135
3136 info->debug = section_objs(info, "__verbose",
3137 sizeof(*info->debug), &info->num_debug);
3138
3139 return 0;
3140}
3141
3142static int move_module(struct module *mod, struct load_info *info)
3143{
3144 int i;
3145 void *ptr;
3146
3147 /* Do the allocs. */
3148 ptr = module_alloc(mod->core_layout.size);
3149 /*
3150 * The pointer to this block is stored in the module structure
3151 * which is inside the block. Just mark it as not being a
3152 * leak.
3153 */
3154 kmemleak_not_leak(ptr);
3155 if (!ptr)
3156 return -ENOMEM;
3157
3158 memset(ptr, 0, mod->core_layout.size);
3159 mod->core_layout.base = ptr;
3160
3161 if (mod->init_layout.size) {
3162 ptr = module_alloc(mod->init_layout.size);
3163 /*
3164 * The pointer to this block is stored in the module structure
3165 * which is inside the block. This block doesn't need to be
3166 * scanned as it contains data and code that will be freed
3167 * after the module is initialized.
3168 */
3169 kmemleak_ignore(ptr);
3170 if (!ptr) {
3171 module_memfree(mod->core_layout.base);
3172 return -ENOMEM;
3173 }
3174 memset(ptr, 0, mod->init_layout.size);
3175 mod->init_layout.base = ptr;
3176 } else
3177 mod->init_layout.base = NULL;
3178
3179 /* Transfer each section which specifies SHF_ALLOC */
3180 pr_debug("final section addresses:\n");
3181 for (i = 0; i < info->hdr->e_shnum; i++) {
3182 void *dest;
3183 Elf_Shdr *shdr = &info->sechdrs[i];
3184
3185 if (!(shdr->sh_flags & SHF_ALLOC))
3186 continue;
3187
3188 if (shdr->sh_entsize & INIT_OFFSET_MASK)
3189 dest = mod->init_layout.base
3190 + (shdr->sh_entsize & ~INIT_OFFSET_MASK);
3191 else
3192 dest = mod->core_layout.base + shdr->sh_entsize;
3193
3194 if (shdr->sh_type != SHT_NOBITS)
3195 memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
3196 /* Update sh_addr to point to copy in image. */
3197 shdr->sh_addr = (unsigned long)dest;
3198 pr_debug("\t0x%lx %s\n",
3199 (long)shdr->sh_addr, info->secstrings + shdr->sh_name);
3200 }
3201
3202 return 0;
3203}
3204
3205static int check_module_license_and_versions(struct module *mod)
3206{
3207 int prev_taint = test_taint(TAINT_PROPRIETARY_MODULE);
3208
3209 /*
3210 * ndiswrapper is under GPL by itself, but loads proprietary modules.
3211 * Don't use add_taint_module(), as it would prevent ndiswrapper from
3212 * using GPL-only symbols it needs.
3213 */
3214 if (strcmp(mod->name, "ndiswrapper") == 0)
3215 add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
3216
3217 /* driverloader was caught wrongly pretending to be under GPL */
3218 if (strcmp(mod->name, "driverloader") == 0)
3219 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3220 LOCKDEP_NOW_UNRELIABLE);
3221
3222 /* lve claims to be GPL but upstream won't provide source */
3223 if (strcmp(mod->name, "lve") == 0)
3224 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3225 LOCKDEP_NOW_UNRELIABLE);
3226
3227 if (!prev_taint && test_taint(TAINT_PROPRIETARY_MODULE))
3228 pr_warn("%s: module license taints kernel.\n", mod->name);
3229
3230#ifdef CONFIG_MODVERSIONS
3231 if ((mod->num_syms && !mod->crcs)
3232 || (mod->num_gpl_syms && !mod->gpl_crcs)
3233 || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
3234#ifdef CONFIG_UNUSED_SYMBOLS
3235 || (mod->num_unused_syms && !mod->unused_crcs)
3236 || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
3237#endif
3238 ) {
3239 return try_to_force_load(mod,
3240 "no versions for exported symbols");
3241 }
3242#endif
3243 return 0;
3244}
3245
3246static void flush_module_icache(const struct module *mod)
3247{
3248 mm_segment_t old_fs;
3249
3250 /* flush the icache in correct context */
3251 old_fs = get_fs();
3252 set_fs(KERNEL_DS);
3253
3254 /*
3255 * Flush the instruction cache, since we've played with text.
3256 * Do it before processing of module parameters, so the module
3257 * can provide parameter accessor functions of its own.
3258 */
3259 if (mod->init_layout.base)
3260 flush_icache_range((unsigned long)mod->init_layout.base,
3261 (unsigned long)mod->init_layout.base
3262 + mod->init_layout.size);
3263 flush_icache_range((unsigned long)mod->core_layout.base,
3264 (unsigned long)mod->core_layout.base + mod->core_layout.size);
3265
3266 set_fs(old_fs);
3267}
3268
3269int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
3270 Elf_Shdr *sechdrs,
3271 char *secstrings,
3272 struct module *mod)
3273{
3274 return 0;
3275}
3276
3277/* module_blacklist is a comma-separated list of module names */
3278static char *module_blacklist;
3279static bool blacklisted(const char *module_name)
3280{
3281 const char *p;
3282 size_t len;
3283
3284 if (!module_blacklist)
3285 return false;
3286
3287 for (p = module_blacklist; *p; p += len) {
3288 len = strcspn(p, ",");
3289 if (strlen(module_name) == len && !memcmp(module_name, p, len))
3290 return true;
3291 if (p[len] == ',')
3292 len++;
3293 }
3294 return false;
3295}
3296core_param(module_blacklist, module_blacklist, charp, 0400);
3297
3298static struct module *layout_and_allocate(struct load_info *info, int flags)
3299{
3300 struct module *mod;
3301 unsigned int ndx;
3302 int err;
3303
3304 err = check_modinfo(info->mod, info, flags);
3305 if (err)
3306 return ERR_PTR(err);
3307
3308 /* Allow arches to frob section contents and sizes. */
3309 err = module_frob_arch_sections(info->hdr, info->sechdrs,
3310 info->secstrings, info->mod);
3311 if (err < 0)
3312 return ERR_PTR(err);
3313
3314 /* We will do a special allocation for per-cpu sections later. */
3315 info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC;
3316
3317 /*
3318 * Mark ro_after_init section with SHF_RO_AFTER_INIT so that
3319 * layout_sections() can put it in the right place.
3320 * Note: ro_after_init sections also have SHF_{WRITE,ALLOC} set.
3321 */
3322 ndx = find_sec(info, ".data..ro_after_init");
3323 if (ndx)
3324 info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT;
3325 /*
3326 * Mark the __jump_table section as ro_after_init as well: these data
3327 * structures are never modified, with the exception of entries that
3328 * refer to code in the __init section, which are annotated as such
3329 * at module load time.
3330 */
3331 ndx = find_sec(info, "__jump_table");
3332 if (ndx)
3333 info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT;
3334
3335 /* Determine total sizes, and put offsets in sh_entsize. For now
3336 this is done generically; there doesn't appear to be any
3337 special cases for the architectures. */
3338 layout_sections(info->mod, info);
3339 layout_symtab(info->mod, info);
3340
3341 /* Allocate and move to the final place */
3342 err = move_module(info->mod, info);
3343 if (err)
3344 return ERR_PTR(err);
3345
3346 /* Module has been copied to its final place now: return it. */
3347 mod = (void *)info->sechdrs[info->index.mod].sh_addr;
3348 kmemleak_load_module(mod, info);
3349 return mod;
3350}
3351
3352/* mod is no longer valid after this! */
3353static void module_deallocate(struct module *mod, struct load_info *info)
3354{
3355 percpu_modfree(mod);
3356 module_arch_freeing_init(mod);
3357 module_memfree(mod->init_layout.base);
3358 module_memfree(mod->core_layout.base);
3359}
3360
3361int __weak module_finalize(const Elf_Ehdr *hdr,
3362 const Elf_Shdr *sechdrs,
3363 struct module *me)
3364{
3365 return 0;
3366}
3367
3368static int post_relocation(struct module *mod, const struct load_info *info)
3369{
3370 /* Sort exception table now relocations are done. */
3371 sort_extable(mod->extable, mod->extable + mod->num_exentries);
3372
3373 /* Copy relocated percpu area over. */
3374 percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
3375 info->sechdrs[info->index.pcpu].sh_size);
3376
3377 /* Setup kallsyms-specific fields. */
3378 add_kallsyms(mod, info);
3379
3380 /* Arch-specific module finalizing. */
3381 return module_finalize(info->hdr, info->sechdrs, mod);
3382}
3383
3384/* Is this module of this name done loading? No locks held. */
3385static bool finished_loading(const char *name)
3386{
3387 struct module *mod;
3388 bool ret;
3389
3390 /*
3391 * The module_mutex should not be a heavily contended lock;
3392 * if we get the occasional sleep here, we'll go an extra iteration
3393 * in the wait_event_interruptible(), which is harmless.
3394 */
3395