projects/linux·blob v4.12-rc4 · refs

4330 lines · 110.1 KiB

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#ifdef CONFIG_STRICT_MODULE_RWX
53#include <asm/set_memory.h>
54#endif
55#include <asm/mmu_context.h>
56#include <linux/license.h>
57#include <asm/sections.h>
58#include <linux/tracepoint.h>
59#include <linux/ftrace.h>
60#include <linux/livepatch.h>
61#include <linux/async.h>
62#include <linux/percpu.h>
63#include <linux/kmemleak.h>
64#include <linux/jump_label.h>
65#include <linux/pfn.h>
66#include <linux/bsearch.h>
67#include <linux/dynamic_debug.h>
68#include <linux/audit.h>
69#include <uapi/linux/module.h>
70#include "module-internal.h"
71
72#define CREATE_TRACE_POINTS
73#include <trace/events/module.h>
74
75#ifndef ARCH_SHF_SMALL
76#define ARCH_SHF_SMALL 0
77#endif
78
79/*
80 * Modules' sections will be aligned on page boundaries
81 * to ensure complete separation of code and data, but
82 * only when CONFIG_STRICT_MODULE_RWX=y
83 */
84#ifdef CONFIG_STRICT_MODULE_RWX
85# define debug_align(X) ALIGN(X, PAGE_SIZE)
86#else
87# define debug_align(X) (X)
88#endif
89
90/* If this is set, the section belongs in the init part of the module */
91#define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
92
93/*
94 * Mutex protects:
95 * 1) List of modules (also safely readable with preempt_disable),
96 * 2) module_use links,
97 * 3) module_addr_min/module_addr_max.
98 * (delete and add uses RCU list operations). */
99DEFINE_MUTEX(module_mutex);
100EXPORT_SYMBOL_GPL(module_mutex);
101static LIST_HEAD(modules);
102
103#ifdef CONFIG_MODULES_TREE_LOOKUP
104
105/*
106 * Use a latched RB-tree for __module_address(); this allows us to use
107 * RCU-sched lookups of the address from any context.
108 *
109 * This is conditional on PERF_EVENTS || TRACING because those can really hit
110 * __module_address() hard by doing a lot of stack unwinding; potentially from
111 * NMI context.
112 */
113
114static __always_inline unsigned long __mod_tree_val(struct latch_tree_node *n)
115{
116 struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
117
118 return (unsigned long)layout->base;
119}
120
121static __always_inline unsigned long __mod_tree_size(struct latch_tree_node *n)
122{
123 struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
124
125 return (unsigned long)layout->size;
126}
127
128static __always_inline bool
129mod_tree_less(struct latch_tree_node *a, struct latch_tree_node *b)
130{
131 return __mod_tree_val(a) < __mod_tree_val(b);
132}
133
134static __always_inline int
135mod_tree_comp(void *key, struct latch_tree_node *n)
136{
137 unsigned long val = (unsigned long)key;
138 unsigned long start, end;
139
140 start = __mod_tree_val(n);
141 if (val < start)
142 return -1;
143
144 end = start + __mod_tree_size(n);
145 if (val >= end)
146 return 1;
147
148 return 0;
149}
150
151static const struct latch_tree_ops mod_tree_ops = {
152 .less = mod_tree_less,
153 .comp = mod_tree_comp,
154};
155
156static struct mod_tree_root {
157 struct latch_tree_root root;
158 unsigned long addr_min;
159 unsigned long addr_max;
160} mod_tree __cacheline_aligned = {
161 .addr_min = -1UL,
162};
163
164#define module_addr_min mod_tree.addr_min
165#define module_addr_max mod_tree.addr_max
166
167static noinline void __mod_tree_insert(struct mod_tree_node *node)
168{
169 latch_tree_insert(&node->node, &mod_tree.root, &mod_tree_ops);
170}
171
172static void __mod_tree_remove(struct mod_tree_node *node)
173{
174 latch_tree_erase(&node->node, &mod_tree.root, &mod_tree_ops);
175}
176
177/*
178 * These modifications: insert, remove_init and remove; are serialized by the
179 * module_mutex.
180 */
181static void mod_tree_insert(struct module *mod)
182{
183 mod->core_layout.mtn.mod = mod;
184 mod->init_layout.mtn.mod = mod;
185
186 __mod_tree_insert(&mod->core_layout.mtn);
187 if (mod->init_layout.size)
188 __mod_tree_insert(&mod->init_layout.mtn);
189}
190
191static void mod_tree_remove_init(struct module *mod)
192{
193 if (mod->init_layout.size)
194 __mod_tree_remove(&mod->init_layout.mtn);
195}
196
197static void mod_tree_remove(struct module *mod)
198{
199 __mod_tree_remove(&mod->core_layout.mtn);
200 mod_tree_remove_init(mod);
201}
202
203static struct module *mod_find(unsigned long addr)
204{
205 struct latch_tree_node *ltn;
206
207 ltn = latch_tree_find((void *)addr, &mod_tree.root, &mod_tree_ops);
208 if (!ltn)
209 return NULL;
210
211 return container_of(ltn, struct mod_tree_node, node)->mod;
212}
213
214#else /* MODULES_TREE_LOOKUP */
215
216static unsigned long module_addr_min = -1UL, module_addr_max = 0;
217
218static void mod_tree_insert(struct module *mod) { }
219static void mod_tree_remove_init(struct module *mod) { }
220static void mod_tree_remove(struct module *mod) { }
221
222static struct module *mod_find(unsigned long addr)
223{
224 struct module *mod;
225
226 list_for_each_entry_rcu(mod, &modules, list) {
227 if (within_module(addr, mod))
228 return mod;
229 }
230
231 return NULL;
232}
233
234#endif /* MODULES_TREE_LOOKUP */
235
236/*
237 * Bounds of module text, for speeding up __module_address.
238 * Protected by module_mutex.
239 */
240static void __mod_update_bounds(void *base, unsigned int size)
241{
242 unsigned long min = (unsigned long)base;
243 unsigned long max = min + size;
244
245 if (min < module_addr_min)
246 module_addr_min = min;
247 if (max > module_addr_max)
248 module_addr_max = max;
249}
250
251static void mod_update_bounds(struct module *mod)
252{
253 __mod_update_bounds(mod->core_layout.base, mod->core_layout.size);
254 if (mod->init_layout.size)
255 __mod_update_bounds(mod->init_layout.base, mod->init_layout.size);
256}
257
258#ifdef CONFIG_KGDB_KDB
259struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
260#endif /* CONFIG_KGDB_KDB */
261
262static void module_assert_mutex(void)
263{
264 lockdep_assert_held(&module_mutex);
265}
266
267static void module_assert_mutex_or_preempt(void)
268{
269#ifdef CONFIG_LOCKDEP
270 if (unlikely(!debug_locks))
271 return;
272
273 WARN_ON_ONCE(!rcu_read_lock_sched_held() &&
274 !lockdep_is_held(&module_mutex));
275#endif
276}
277
278static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE);
279#ifndef CONFIG_MODULE_SIG_FORCE
280module_param(sig_enforce, bool_enable_only, 0644);
281#endif /* !CONFIG_MODULE_SIG_FORCE */
282
283/* Block module loading/unloading? */
284int modules_disabled = 0;
285core_param(nomodule, modules_disabled, bint, 0);
286
287/* Waiting for a module to finish initializing? */
288static DECLARE_WAIT_QUEUE_HEAD(module_wq);
289
290static BLOCKING_NOTIFIER_HEAD(module_notify_list);
291
292int register_module_notifier(struct notifier_block *nb)
293{
294 return blocking_notifier_chain_register(&module_notify_list, nb);
295}
296EXPORT_SYMBOL(register_module_notifier);
297
298int unregister_module_notifier(struct notifier_block *nb)
299{
300 return blocking_notifier_chain_unregister(&module_notify_list, nb);
301}
302EXPORT_SYMBOL(unregister_module_notifier);
303
304struct load_info {
305 Elf_Ehdr *hdr;
306 unsigned long len;
307 Elf_Shdr *sechdrs;
308 char *secstrings, *strtab;
309 unsigned long symoffs, stroffs;
310 struct _ddebug *debug;
311 unsigned int num_debug;
312 bool sig_ok;
313#ifdef CONFIG_KALLSYMS
314 unsigned long mod_kallsyms_init_off;
315#endif
316 struct {
317 unsigned int sym, str, mod, vers, info, pcpu;
318 } index;
319};
320
321/*
322 * We require a truly strong try_module_get(): 0 means success.
323 * Otherwise an error is returned due to ongoing or failed
324 * initialization etc.
325 */
326static inline int strong_try_module_get(struct module *mod)
327{
328 BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED);
329 if (mod && mod->state == MODULE_STATE_COMING)
330 return -EBUSY;
331 if (try_module_get(mod))
332 return 0;
333 else
334 return -ENOENT;
335}
336
337static inline void add_taint_module(struct module *mod, unsigned flag,
338 enum lockdep_ok lockdep_ok)
339{
340 add_taint(flag, lockdep_ok);
341 set_bit(flag, &mod->taints);
342}
343
344/*
345 * A thread that wants to hold a reference to a module only while it
346 * is running can call this to safely exit. nfsd and lockd use this.
347 */
348void __noreturn __module_put_and_exit(struct module *mod, long code)
349{
350 module_put(mod);
351 do_exit(code);
352}
353EXPORT_SYMBOL(__module_put_and_exit);
354
355/* Find a module section: 0 means not found. */
356static unsigned int find_sec(const struct load_info *info, const char *name)
357{
358 unsigned int i;
359
360 for (i = 1; i < info->hdr->e_shnum; i++) {
361 Elf_Shdr *shdr = &info->sechdrs[i];
362 /* Alloc bit cleared means "ignore it." */
363 if ((shdr->sh_flags & SHF_ALLOC)
364 && strcmp(info->secstrings + shdr->sh_name, name) == 0)
365 return i;
366 }
367 return 0;
368}
369
370/* Find a module section, or NULL. */
371static void *section_addr(const struct load_info *info, const char *name)
372{
373 /* Section 0 has sh_addr 0. */
374 return (void *)info->sechdrs[find_sec(info, name)].sh_addr;
375}
376
377/* Find a module section, or NULL. Fill in number of "objects" in section. */
378static void *section_objs(const struct load_info *info,
379 const char *name,
380 size_t object_size,
381 unsigned int *num)
382{
383 unsigned int sec = find_sec(info, name);
384
385 /* Section 0 has sh_addr 0 and sh_size 0. */
386 *num = info->sechdrs[sec].sh_size / object_size;
387 return (void *)info->sechdrs[sec].sh_addr;
388}
389
390/* Provided by the linker */
391extern const struct kernel_symbol __start___ksymtab[];
392extern const struct kernel_symbol __stop___ksymtab[];
393extern const struct kernel_symbol __start___ksymtab_gpl[];
394extern const struct kernel_symbol __stop___ksymtab_gpl[];
395extern const struct kernel_symbol __start___ksymtab_gpl_future[];
396extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
397extern const s32 __start___kcrctab[];
398extern const s32 __start___kcrctab_gpl[];
399extern const s32 __start___kcrctab_gpl_future[];
400#ifdef CONFIG_UNUSED_SYMBOLS
401extern const struct kernel_symbol __start___ksymtab_unused[];
402extern const struct kernel_symbol __stop___ksymtab_unused[];
403extern const struct kernel_symbol __start___ksymtab_unused_gpl[];
404extern const struct kernel_symbol __stop___ksymtab_unused_gpl[];
405extern const s32 __start___kcrctab_unused[];
406extern const s32 __start___kcrctab_unused_gpl[];
407#endif
408
409#ifndef CONFIG_MODVERSIONS
410#define symversion(base, idx) NULL
411#else
412#define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
413#endif
414
415static bool each_symbol_in_section(const struct symsearch *arr,
416 unsigned int arrsize,
417 struct module *owner,
418 bool (*fn)(const struct symsearch *syms,
419 struct module *owner,
420 void *data),
421 void *data)
422{
423 unsigned int j;
424
425 for (j = 0; j < arrsize; j++) {
426 if (fn(&arr[j], owner, data))
427 return true;
428 }
429
430 return false;
431}
432
433/* Returns true as soon as fn returns true, otherwise false. */
434bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
435 struct module *owner,
436 void *data),
437 void *data)
438{
439 struct module *mod;
440 static const struct symsearch arr[] = {
441 { __start___ksymtab, __stop___ksymtab, __start___kcrctab,
442 NOT_GPL_ONLY, false },
443 { __start___ksymtab_gpl, __stop___ksymtab_gpl,
444 __start___kcrctab_gpl,
445 GPL_ONLY, false },
446 { __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future,
447 __start___kcrctab_gpl_future,
448 WILL_BE_GPL_ONLY, false },
449#ifdef CONFIG_UNUSED_SYMBOLS
450 { __start___ksymtab_unused, __stop___ksymtab_unused,
451 __start___kcrctab_unused,
452 NOT_GPL_ONLY, true },
453 { __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl,
454 __start___kcrctab_unused_gpl,
455 GPL_ONLY, true },
456#endif
457 };
458
459 module_assert_mutex_or_preempt();
460
461 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data))
462 return true;
463
464 list_for_each_entry_rcu(mod, &modules, list) {
465 struct symsearch arr[] = {
466 { mod->syms, mod->syms + mod->num_syms, mod->crcs,
467 NOT_GPL_ONLY, false },
468 { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
469 mod->gpl_crcs,
470 GPL_ONLY, false },
471 { mod->gpl_future_syms,
472 mod->gpl_future_syms + mod->num_gpl_future_syms,
473 mod->gpl_future_crcs,
474 WILL_BE_GPL_ONLY, false },
475#ifdef CONFIG_UNUSED_SYMBOLS
476 { mod->unused_syms,
477 mod->unused_syms + mod->num_unused_syms,
478 mod->unused_crcs,
479 NOT_GPL_ONLY, true },
480 { mod->unused_gpl_syms,
481 mod->unused_gpl_syms + mod->num_unused_gpl_syms,
482 mod->unused_gpl_crcs,
483 GPL_ONLY, true },
484#endif
485 };
486
487 if (mod->state == MODULE_STATE_UNFORMED)
488 continue;
489
490 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data))
491 return true;
492 }
493 return false;
494}
495EXPORT_SYMBOL_GPL(each_symbol_section);
496
497struct find_symbol_arg {
498 /* Input */
499 const char *name;
500 bool gplok;
501 bool warn;
502
503 /* Output */
504 struct module *owner;
505 const s32 *crc;
506 const struct kernel_symbol *sym;
507};
508
509static bool check_symbol(const struct symsearch *syms,
510 struct module *owner,
511 unsigned int symnum, void *data)
512{
513 struct find_symbol_arg *fsa = data;
514
515 if (!fsa->gplok) {
516 if (syms->licence == GPL_ONLY)
517 return false;
518 if (syms->licence == WILL_BE_GPL_ONLY && fsa->warn) {
519 pr_warn("Symbol %s is being used by a non-GPL module, "
520 "which will not be allowed in the future\n",
521 fsa->name);
522 }
523 }
524
525#ifdef CONFIG_UNUSED_SYMBOLS
526 if (syms->unused && fsa->warn) {
527 pr_warn("Symbol %s is marked as UNUSED, however this module is "
528 "using it.\n", fsa->name);
529 pr_warn("This symbol will go away in the future.\n");
530 pr_warn("Please evaluate if this is the right api to use and "
531 "if it really is, submit a report to the linux kernel "
532 "mailing list together with submitting your code for "
533 "inclusion.\n");
534 }
535#endif
536
537 fsa->owner = owner;
538 fsa->crc = symversion(syms->crcs, symnum);
539 fsa->sym = &syms->start[symnum];
540 return true;
541}
542
543static int cmp_name(const void *va, const void *vb)
544{
545 const char *a;
546 const struct kernel_symbol *b;
547 a = va; b = vb;
548 return strcmp(a, b->name);
549}
550
551static bool find_symbol_in_section(const struct symsearch *syms,
552 struct module *owner,
553 void *data)
554{
555 struct find_symbol_arg *fsa = data;
556 struct kernel_symbol *sym;
557
558 sym = bsearch(fsa->name, syms->start, syms->stop - syms->start,
559 sizeof(struct kernel_symbol), cmp_name);
560
561 if (sym != NULL && check_symbol(syms, owner, sym - syms->start, data))
562 return true;
563
564 return false;
565}
566
567/* Find a symbol and return it, along with, (optional) crc and
568 * (optional) module which owns it. Needs preempt disabled or module_mutex. */
569const struct kernel_symbol *find_symbol(const char *name,
570 struct module **owner,
571 const s32 **crc,
572 bool gplok,
573 bool warn)
574{
575 struct find_symbol_arg fsa;
576
577 fsa.name = name;
578 fsa.gplok = gplok;
579 fsa.warn = warn;
580
581 if (each_symbol_section(find_symbol_in_section, &fsa)) {
582 if (owner)
583 *owner = fsa.owner;
584 if (crc)
585 *crc = fsa.crc;
586 return fsa.sym;
587 }
588
589 pr_debug("Failed to find symbol %s\n", name);
590 return NULL;
591}
592EXPORT_SYMBOL_GPL(find_symbol);
593
594/*
595 * Search for module by name: must hold module_mutex (or preempt disabled
596 * for read-only access).
597 */
598static struct module *find_module_all(const char *name, size_t len,
599 bool even_unformed)
600{
601 struct module *mod;
602
603 module_assert_mutex_or_preempt();
604
605 list_for_each_entry(mod, &modules, list) {
606 if (!even_unformed && mod->state == MODULE_STATE_UNFORMED)
607 continue;
608 if (strlen(mod->name) == len && !memcmp(mod->name, name, len))
609 return mod;
610 }
611 return NULL;
612}
613
614struct module *find_module(const char *name)
615{
616 module_assert_mutex();
617 return find_module_all(name, strlen(name), false);
618}
619EXPORT_SYMBOL_GPL(find_module);
620
621#ifdef CONFIG_SMP
622
623static inline void __percpu *mod_percpu(struct module *mod)
624{
625 return mod->percpu;
626}
627
628static int percpu_modalloc(struct module *mod, struct load_info *info)
629{
630 Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu];
631 unsigned long align = pcpusec->sh_addralign;
632
633 if (!pcpusec->sh_size)
634 return 0;
635
636 if (align > PAGE_SIZE) {
637 pr_warn("%s: per-cpu alignment %li > %li\n",
638 mod->name, align, PAGE_SIZE);
639 align = PAGE_SIZE;
640 }
641
642 mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align);
643 if (!mod->percpu) {
644 pr_warn("%s: Could not allocate %lu bytes percpu data\n",
645 mod->name, (unsigned long)pcpusec->sh_size);
646 return -ENOMEM;
647 }
648 mod->percpu_size = pcpusec->sh_size;
649 return 0;
650}
651
652static void percpu_modfree(struct module *mod)
653{
654 free_percpu(mod->percpu);
655}
656
657static unsigned int find_pcpusec(struct load_info *info)
658{
659 return find_sec(info, ".data..percpu");
660}
661
662static void percpu_modcopy(struct module *mod,
663 const void *from, unsigned long size)
664{
665 int cpu;
666
667 for_each_possible_cpu(cpu)
668 memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
669}
670
671bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
672{
673 struct module *mod;
674 unsigned int cpu;
675
676 preempt_disable();
677
678 list_for_each_entry_rcu(mod, &modules, list) {
679 if (mod->state == MODULE_STATE_UNFORMED)
680 continue;
681 if (!mod->percpu_size)
682 continue;
683 for_each_possible_cpu(cpu) {
684 void *start = per_cpu_ptr(mod->percpu, cpu);
685 void *va = (void *)addr;
686
687 if (va >= start && va < start + mod->percpu_size) {
688 if (can_addr) {
689 *can_addr = (unsigned long) (va - start);
690 *can_addr += (unsigned long)
691 per_cpu_ptr(mod->percpu,
692 get_boot_cpu_id());
693 }
694 preempt_enable();
695 return true;
696 }
697 }
698 }
699
700 preempt_enable();
701 return false;
702}
703
704/**
705 * is_module_percpu_address - test whether address is from module static percpu
706 * @addr: address to test
707 *
708 * Test whether @addr belongs to module static percpu area.
709 *
710 * RETURNS:
711 * %true if @addr is from module static percpu area
712 */
713bool is_module_percpu_address(unsigned long addr)
714{
715 return __is_module_percpu_address(addr, NULL);
716}
717
718#else /* ... !CONFIG_SMP */
719
720static inline void __percpu *mod_percpu(struct module *mod)
721{
722 return NULL;
723}
724static int percpu_modalloc(struct module *mod, struct load_info *info)
725{
726 /* UP modules shouldn't have this section: ENOMEM isn't quite right */
727 if (info->sechdrs[info->index.pcpu].sh_size != 0)
728 return -ENOMEM;
729 return 0;
730}
731static inline void percpu_modfree(struct module *mod)
732{
733}
734static unsigned int find_pcpusec(struct load_info *info)
735{
736 return 0;
737}
738static inline void percpu_modcopy(struct module *mod,
739 const void *from, unsigned long size)
740{
741 /* pcpusec should be 0, and size of that section should be 0. */
742 BUG_ON(size != 0);
743}
744bool is_module_percpu_address(unsigned long addr)
745{
746 return false;
747}
748
749bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
750{
751 return false;
752}
753
754#endif /* CONFIG_SMP */
755
756#define MODINFO_ATTR(field) \
757static void setup_modinfo_##field(struct module *mod, const char *s) \
758{ \
759 mod->field = kstrdup(s, GFP_KERNEL); \
760} \
761static ssize_t show_modinfo_##field(struct module_attribute *mattr, \
762 struct module_kobject *mk, char *buffer) \
763{ \
764 return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field); \
765} \
766static int modinfo_##field##_exists(struct module *mod) \
767{ \
768 return mod->field != NULL; \
769} \
770static void free_modinfo_##field(struct module *mod) \
771{ \
772 kfree(mod->field); \
773 mod->field = NULL; \
774} \
775static struct module_attribute modinfo_##field = { \
776 .attr = { .name = __stringify(field), .mode = 0444 }, \
777 .show = show_modinfo_##field, \
778 .setup = setup_modinfo_##field, \
779 .test = modinfo_##field##_exists, \
780 .free = free_modinfo_##field, \
781};
782
783MODINFO_ATTR(version);
784MODINFO_ATTR(srcversion);
785
786static char last_unloaded_module[MODULE_NAME_LEN+1];
787
788#ifdef CONFIG_MODULE_UNLOAD
789
790EXPORT_TRACEPOINT_SYMBOL(module_get);
791
792/* MODULE_REF_BASE is the base reference count by kmodule loader. */
793#define MODULE_REF_BASE 1
794
795/* Init the unload section of the module. */
796static int module_unload_init(struct module *mod)
797{
798 /*
799 * Initialize reference counter to MODULE_REF_BASE.
800 * refcnt == 0 means module is going.
801 */
802 atomic_set(&mod->refcnt, MODULE_REF_BASE);
803
804 INIT_LIST_HEAD(&mod->source_list);
805 INIT_LIST_HEAD(&mod->target_list);
806
807 /* Hold reference count during initialization. */
808 atomic_inc(&mod->refcnt);
809
810 return 0;
811}
812
813/* Does a already use b? */
814static int already_uses(struct module *a, struct module *b)
815{
816 struct module_use *use;
817
818 list_for_each_entry(use, &b->source_list, source_list) {
819 if (use->source == a) {
820 pr_debug("%s uses %s!\n", a->name, b->name);
821 return 1;
822 }
823 }
824 pr_debug("%s does not use %s!\n", a->name, b->name);
825 return 0;
826}
827
828/*
829 * Module a uses b
830 * - we add 'a' as a "source", 'b' as a "target" of module use
831 * - the module_use is added to the list of 'b' sources (so
832 * 'b' can walk the list to see who sourced them), and of 'a'
833 * targets (so 'a' can see what modules it targets).
834 */
835static int add_module_usage(struct module *a, struct module *b)
836{
837 struct module_use *use;
838
839 pr_debug("Allocating new usage for %s.\n", a->name);
840 use = kmalloc(sizeof(*use), GFP_ATOMIC);
841 if (!use) {
842 pr_warn("%s: out of memory loading\n", a->name);
843 return -ENOMEM;
844 }
845
846 use->source = a;
847 use->target = b;
848 list_add(&use->source_list, &b->source_list);
849 list_add(&use->target_list, &a->target_list);
850 return 0;
851}
852
853/* Module a uses b: caller needs module_mutex() */
854int ref_module(struct module *a, struct module *b)
855{
856 int err;
857
858 if (b == NULL || already_uses(a, b))
859 return 0;
860
861 /* If module isn't available, we fail. */
862 err = strong_try_module_get(b);
863 if (err)
864 return err;
865
866 err = add_module_usage(a, b);
867 if (err) {
868 module_put(b);
869 return err;
870 }
871 return 0;
872}
873EXPORT_SYMBOL_GPL(ref_module);
874
875/* Clear the unload stuff of the module. */
876static void module_unload_free(struct module *mod)
877{
878 struct module_use *use, *tmp;
879
880 mutex_lock(&module_mutex);
881 list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
882 struct module *i = use->target;
883 pr_debug("%s unusing %s\n", mod->name, i->name);
884 module_put(i);
885 list_del(&use->source_list);
886 list_del(&use->target_list);
887 kfree(use);
888 }
889 mutex_unlock(&module_mutex);
890}
891
892#ifdef CONFIG_MODULE_FORCE_UNLOAD
893static inline int try_force_unload(unsigned int flags)
894{
895 int ret = (flags & O_TRUNC);
896 if (ret)
897 add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE);
898 return ret;
899}
900#else
901static inline int try_force_unload(unsigned int flags)
902{
903 return 0;
904}
905#endif /* CONFIG_MODULE_FORCE_UNLOAD */
906
907/* Try to release refcount of module, 0 means success. */
908static int try_release_module_ref(struct module *mod)
909{
910 int ret;
911
912 /* Try to decrement refcnt which we set at loading */
913 ret = atomic_sub_return(MODULE_REF_BASE, &mod->refcnt);
914 BUG_ON(ret < 0);
915 if (ret)
916 /* Someone can put this right now, recover with checking */
917 ret = atomic_add_unless(&mod->refcnt, MODULE_REF_BASE, 0);
918
919 return ret;
920}
921
922static int try_stop_module(struct module *mod, int flags, int *forced)
923{
924 /* If it's not unused, quit unless we're forcing. */
925 if (try_release_module_ref(mod) != 0) {
926 *forced = try_force_unload(flags);
927 if (!(*forced))
928 return -EWOULDBLOCK;
929 }
930
931 /* Mark it as dying. */
932 mod->state = MODULE_STATE_GOING;
933
934 return 0;
935}
936
937/**
938 * module_refcount - return the refcount or -1 if unloading
939 *
940 * @mod: the module we're checking
941 *
942 * Returns:
943 * -1 if the module is in the process of unloading
944 * otherwise the number of references in the kernel to the module
945 */
946int module_refcount(struct module *mod)
947{
948 return atomic_read(&mod->refcnt) - MODULE_REF_BASE;
949}
950EXPORT_SYMBOL(module_refcount);
951
952/* This exists whether we can unload or not */
953static void free_module(struct module *mod);
954
955SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
956 unsigned int, flags)
957{
958 struct module *mod;
959 char name[MODULE_NAME_LEN];
960 int ret, forced = 0;
961
962 if (!capable(CAP_SYS_MODULE) || modules_disabled)
963 return -EPERM;
964
965 if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
966 return -EFAULT;
967 name[MODULE_NAME_LEN-1] = '\0';
968
969 audit_log_kern_module(name);
970
971 if (mutex_lock_interruptible(&module_mutex) != 0)
972 return -EINTR;
973
974 mod = find_module(name);
975 if (!mod) {
976 ret = -ENOENT;
977 goto out;
978 }
979
980 if (!list_empty(&mod->source_list)) {
981 /* Other modules depend on us: get rid of them first. */
982 ret = -EWOULDBLOCK;
983 goto out;
984 }
985
986 /* Doing init or already dying? */
987 if (mod->state != MODULE_STATE_LIVE) {
988 /* FIXME: if (force), slam module count damn the torpedoes */
989 pr_debug("%s already dying\n", mod->name);
990 ret = -EBUSY;
991 goto out;
992 }
993
994 /* If it has an init func, it must have an exit func to unload */
995 if (mod->init && !mod->exit) {
996 forced = try_force_unload(flags);
997 if (!forced) {
998 /* This module can't be removed */
999 ret = -EBUSY;
1000 goto out;
1001 }
1002 }
1003
1004 /* Stop the machine so refcounts can't move and disable module. */
1005 ret = try_stop_module(mod, flags, &forced);
1006 if (ret != 0)
1007 goto out;
1008
1009 mutex_unlock(&module_mutex);
1010 /* Final destruction now no one is using it. */
1011 if (mod->exit != NULL)
1012 mod->exit();
1013 blocking_notifier_call_chain(&module_notify_list,
1014 MODULE_STATE_GOING, mod);
1015 klp_module_going(mod);
1016 ftrace_release_mod(mod);
1017
1018 async_synchronize_full();
1019
1020 /* Store the name of the last unloaded module for diagnostic purposes */
1021 strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
1022
1023 free_module(mod);
1024 return 0;
1025out:
1026 mutex_unlock(&module_mutex);
1027 return ret;
1028}
1029
1030static inline void print_unload_info(struct seq_file *m, struct module *mod)
1031{
1032 struct module_use *use;
1033 int printed_something = 0;
1034
1035 seq_printf(m, " %i ", module_refcount(mod));
1036
1037 /*
1038 * Always include a trailing , so userspace can differentiate
1039 * between this and the old multi-field proc format.
1040 */
1041 list_for_each_entry(use, &mod->source_list, source_list) {
1042 printed_something = 1;
1043 seq_printf(m, "%s,", use->source->name);
1044 }
1045
1046 if (mod->init != NULL && mod->exit == NULL) {
1047 printed_something = 1;
1048 seq_puts(m, "[permanent],");
1049 }
1050
1051 if (!printed_something)
1052 seq_puts(m, "-");
1053}
1054
1055void __symbol_put(const char *symbol)
1056{
1057 struct module *owner;
1058
1059 preempt_disable();
1060 if (!find_symbol(symbol, &owner, NULL, true, false))
1061 BUG();
1062 module_put(owner);
1063 preempt_enable();
1064}
1065EXPORT_SYMBOL(__symbol_put);
1066
1067/* Note this assumes addr is a function, which it currently always is. */
1068void symbol_put_addr(void *addr)
1069{
1070 struct module *modaddr;
1071 unsigned long a = (unsigned long)dereference_function_descriptor(addr);
1072
1073 if (core_kernel_text(a))
1074 return;
1075
1076 /*
1077 * Even though we hold a reference on the module; we still need to
1078 * disable preemption in order to safely traverse the data structure.
1079 */
1080 preempt_disable();
1081 modaddr = __module_text_address(a);
1082 BUG_ON(!modaddr);
1083 module_put(modaddr);
1084 preempt_enable();
1085}
1086EXPORT_SYMBOL_GPL(symbol_put_addr);
1087
1088static ssize_t show_refcnt(struct module_attribute *mattr,
1089 struct module_kobject *mk, char *buffer)
1090{
1091 return sprintf(buffer, "%i\n", module_refcount(mk->mod));
1092}
1093
1094static struct module_attribute modinfo_refcnt =
1095 __ATTR(refcnt, 0444, show_refcnt, NULL);
1096
1097void __module_get(struct module *module)
1098{
1099 if (module) {
1100 preempt_disable();
1101 atomic_inc(&module->refcnt);
1102 trace_module_get(module, _RET_IP_);
1103 preempt_enable();
1104 }
1105}
1106EXPORT_SYMBOL(__module_get);
1107
1108bool try_module_get(struct module *module)
1109{
1110 bool ret = true;
1111
1112 if (module) {
1113 preempt_disable();
1114 /* Note: here, we can fail to get a reference */
1115 if (likely(module_is_live(module) &&
1116 atomic_inc_not_zero(&module->refcnt) != 0))
1117 trace_module_get(module, _RET_IP_);
1118 else
1119 ret = false;
1120
1121 preempt_enable();
1122 }
1123 return ret;
1124}
1125EXPORT_SYMBOL(try_module_get);
1126
1127void module_put(struct module *module)
1128{
1129 int ret;
1130
1131 if (module) {
1132 preempt_disable();
1133 ret = atomic_dec_if_positive(&module->refcnt);
1134 WARN_ON(ret < 0); /* Failed to put refcount */
1135 trace_module_put(module, _RET_IP_);
1136 preempt_enable();
1137 }
1138}
1139EXPORT_SYMBOL(module_put);
1140
1141#else /* !CONFIG_MODULE_UNLOAD */
1142static inline void print_unload_info(struct seq_file *m, struct module *mod)
1143{
1144 /* We don't know the usage count, or what modules are using. */
1145 seq_puts(m, " - -");
1146}
1147
1148static inline void module_unload_free(struct module *mod)
1149{
1150}
1151
1152int ref_module(struct module *a, struct module *b)
1153{
1154 return strong_try_module_get(b);
1155}
1156EXPORT_SYMBOL_GPL(ref_module);
1157
1158static inline int module_unload_init(struct module *mod)
1159{
1160 return 0;
1161}
1162#endif /* CONFIG_MODULE_UNLOAD */
1163
1164static size_t module_flags_taint(struct module *mod, char *buf)
1165{
1166 size_t l = 0;
1167 int i;
1168
1169 for (i = 0; i < TAINT_FLAGS_COUNT; i++) {
1170 if (taint_flags[i].module && test_bit(i, &mod->taints))
1171 buf[l++] = taint_flags[i].c_true;
1172 }
1173
1174 return l;
1175}
1176
1177static ssize_t show_initstate(struct module_attribute *mattr,
1178 struct module_kobject *mk, char *buffer)
1179{
1180 const char *state = "unknown";
1181
1182 switch (mk->mod->state) {
1183 case MODULE_STATE_LIVE:
1184 state = "live";
1185 break;
1186 case MODULE_STATE_COMING:
1187 state = "coming";
1188 break;
1189 case MODULE_STATE_GOING:
1190 state = "going";
1191 break;
1192 default:
1193 BUG();
1194 }
1195 return sprintf(buffer, "%s\n", state);
1196}
1197
1198static struct module_attribute modinfo_initstate =
1199 __ATTR(initstate, 0444, show_initstate, NULL);
1200
1201static ssize_t store_uevent(struct module_attribute *mattr,
1202 struct module_kobject *mk,
1203 const char *buffer, size_t count)
1204{
1205 enum kobject_action action;
1206
1207 if (kobject_action_type(buffer, count, &action) == 0)
1208 kobject_uevent(&mk->kobj, action);
1209 return count;
1210}
1211
1212struct module_attribute module_uevent =
1213 __ATTR(uevent, 0200, NULL, store_uevent);
1214
1215static ssize_t show_coresize(struct module_attribute *mattr,
1216 struct module_kobject *mk, char *buffer)
1217{
1218 return sprintf(buffer, "%u\n", mk->mod->core_layout.size);
1219}
1220
1221static struct module_attribute modinfo_coresize =
1222 __ATTR(coresize, 0444, show_coresize, NULL);
1223
1224static ssize_t show_initsize(struct module_attribute *mattr,
1225 struct module_kobject *mk, char *buffer)
1226{
1227 return sprintf(buffer, "%u\n", mk->mod->init_layout.size);
1228}
1229
1230static struct module_attribute modinfo_initsize =
1231 __ATTR(initsize, 0444, show_initsize, NULL);
1232
1233static ssize_t show_taint(struct module_attribute *mattr,
1234 struct module_kobject *mk, char *buffer)
1235{
1236 size_t l;
1237
1238 l = module_flags_taint(mk->mod, buffer);
1239 buffer[l++] = '\n';
1240 return l;
1241}
1242
1243static struct module_attribute modinfo_taint =
1244 __ATTR(taint, 0444, show_taint, NULL);
1245
1246static struct module_attribute *modinfo_attrs[] = {
1247 &module_uevent,
1248 &modinfo_version,
1249 &modinfo_srcversion,
1250 &modinfo_initstate,
1251 &modinfo_coresize,
1252 &modinfo_initsize,
1253 &modinfo_taint,
1254#ifdef CONFIG_MODULE_UNLOAD
1255 &modinfo_refcnt,
1256#endif
1257 NULL,
1258};
1259
1260static const char vermagic[] = VERMAGIC_STRING;
1261
1262static int try_to_force_load(struct module *mod, const char *reason)
1263{
1264#ifdef CONFIG_MODULE_FORCE_LOAD
1265 if (!test_taint(TAINT_FORCED_MODULE))
1266 pr_warn("%s: %s: kernel tainted.\n", mod->name, reason);
1267 add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
1268 return 0;
1269#else
1270 return -ENOEXEC;
1271#endif
1272}
1273
1274#ifdef CONFIG_MODVERSIONS
1275
1276static u32 resolve_rel_crc(const s32 *crc)
1277{
1278 return *(u32 *)((void *)crc + *crc);
1279}
1280
1281static int check_version(Elf_Shdr *sechdrs,
1282 unsigned int versindex,
1283 const char *symname,
1284 struct module *mod,
1285 const s32 *crc)
1286{
1287 unsigned int i, num_versions;
1288 struct modversion_info *versions;
1289
1290 /* Exporting module didn't supply crcs? OK, we're already tainted. */
1291 if (!crc)
1292 return 1;
1293
1294 /* No versions at all? modprobe --force does this. */
1295 if (versindex == 0)
1296 return try_to_force_load(mod, symname) == 0;
1297
1298 versions = (void *) sechdrs[versindex].sh_addr;
1299 num_versions = sechdrs[versindex].sh_size
1300 / sizeof(struct modversion_info);
1301
1302 for (i = 0; i < num_versions; i++) {
1303 u32 crcval;
1304
1305 if (strcmp(versions[i].name, symname) != 0)
1306 continue;
1307
1308 if (IS_ENABLED(CONFIG_MODULE_REL_CRCS))
1309 crcval = resolve_rel_crc(crc);
1310 else
1311 crcval = *crc;
1312 if (versions[i].crc == crcval)
1313 return 1;
1314 pr_debug("Found checksum %X vs module %lX\n",
1315 crcval, versions[i].crc);
1316 goto bad_version;
1317 }
1318
1319 /* Broken toolchain. Warn once, then let it go.. */
1320 pr_warn_once("%s: no symbol version for %s\n", mod->name, symname);
1321 return 1;
1322
1323bad_version:
1324 pr_warn("%s: disagrees about version of symbol %s\n",
1325 mod->name, symname);
1326 return 0;
1327}
1328
1329static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1330 unsigned int versindex,
1331 struct module *mod)
1332{
1333 const s32 *crc;
1334
1335 /*
1336 * Since this should be found in kernel (which can't be removed), no
1337 * locking is necessary -- use preempt_disable() to placate lockdep.
1338 */
1339 preempt_disable();
1340 if (!find_symbol(VMLINUX_SYMBOL_STR(module_layout), NULL,
1341 &crc, true, false)) {
1342 preempt_enable();
1343 BUG();
1344 }
1345 preempt_enable();
1346 return check_version(sechdrs, versindex,
1347 VMLINUX_SYMBOL_STR(module_layout), mod, crc);
1348}
1349
1350/* First part is kernel version, which we ignore if module has crcs. */
1351static inline int same_magic(const char *amagic, const char *bmagic,
1352 bool has_crcs)
1353{
1354 if (has_crcs) {
1355 amagic += strcspn(amagic, " ");
1356 bmagic += strcspn(bmagic, " ");
1357 }
1358 return strcmp(amagic, bmagic) == 0;
1359}
1360#else
1361static inline int check_version(Elf_Shdr *sechdrs,
1362 unsigned int versindex,
1363 const char *symname,
1364 struct module *mod,
1365 const s32 *crc)
1366{
1367 return 1;
1368}
1369
1370static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1371 unsigned int versindex,
1372 struct module *mod)
1373{
1374 return 1;
1375}
1376
1377static inline int same_magic(const char *amagic, const char *bmagic,
1378 bool has_crcs)
1379{
1380 return strcmp(amagic, bmagic) == 0;
1381}
1382#endif /* CONFIG_MODVERSIONS */
1383
1384/* Resolve a symbol for this module. I.e. if we find one, record usage. */
1385static const struct kernel_symbol *resolve_symbol(struct module *mod,
1386 const struct load_info *info,
1387 const char *name,
1388 char ownername[])
1389{
1390 struct module *owner;
1391 const struct kernel_symbol *sym;
1392 const s32 *crc;
1393 int err;
1394
1395 /*
1396 * The module_mutex should not be a heavily contended lock;
1397 * if we get the occasional sleep here, we'll go an extra iteration
1398 * in the wait_event_interruptible(), which is harmless.
1399 */
1400 sched_annotate_sleep();
1401 mutex_lock(&module_mutex);
1402 sym = find_symbol(name, &owner, &crc,
1403 !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
1404 if (!sym)
1405 goto unlock;
1406
1407 if (!check_version(info->sechdrs, info->index.vers, name, mod, crc)) {
1408 sym = ERR_PTR(-EINVAL);
1409 goto getname;
1410 }
1411
1412 err = ref_module(mod, owner);
1413 if (err) {
1414 sym = ERR_PTR(err);
1415 goto getname;
1416 }
1417
1418getname:
1419 /* We must make copy under the lock if we failed to get ref. */
1420 strncpy(ownername, module_name(owner), MODULE_NAME_LEN);
1421unlock:
1422 mutex_unlock(&module_mutex);
1423 return sym;
1424}
1425
1426static const struct kernel_symbol *
1427resolve_symbol_wait(struct module *mod,
1428 const struct load_info *info,
1429 const char *name)
1430{
1431 const struct kernel_symbol *ksym;
1432 char owner[MODULE_NAME_LEN];
1433
1434 if (wait_event_interruptible_timeout(module_wq,
1435 !IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
1436 || PTR_ERR(ksym) != -EBUSY,
1437 30 * HZ) <= 0) {
1438 pr_warn("%s: gave up waiting for init of module %s.\n",
1439 mod->name, owner);
1440 }
1441 return ksym;
1442}
1443
1444/*
1445 * /sys/module/foo/sections stuff
1446 * J. Corbet <[email protected]>
1447 */
1448#ifdef CONFIG_SYSFS
1449
1450#ifdef CONFIG_KALLSYMS
1451static inline bool sect_empty(const Elf_Shdr *sect)
1452{
1453 return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
1454}
1455
1456struct module_sect_attr {
1457 struct module_attribute mattr;
1458 char *name;
1459 unsigned long address;
1460};
1461
1462struct module_sect_attrs {
1463 struct attribute_group grp;
1464 unsigned int nsections;
1465 struct module_sect_attr attrs[0];
1466};
1467
1468static ssize_t module_sect_show(struct module_attribute *mattr,
1469 struct module_kobject *mk, char *buf)
1470{
1471 struct module_sect_attr *sattr =
1472 container_of(mattr, struct module_sect_attr, mattr);
1473 return sprintf(buf, "0x%pK\n", (void *)sattr->address);
1474}
1475
1476static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
1477{
1478 unsigned int section;
1479
1480 for (section = 0; section < sect_attrs->nsections; section++)
1481 kfree(sect_attrs->attrs[section].name);
1482 kfree(sect_attrs);
1483}
1484
1485static void add_sect_attrs(struct module *mod, const struct load_info *info)
1486{
1487 unsigned int nloaded = 0, i, size[2];
1488 struct module_sect_attrs *sect_attrs;
1489 struct module_sect_attr *sattr;
1490 struct attribute **gattr;
1491
1492 /* Count loaded sections and allocate structures */
1493 for (i = 0; i < info->hdr->e_shnum; i++)
1494 if (!sect_empty(&info->sechdrs[i]))
1495 nloaded++;
1496 size[0] = ALIGN(sizeof(*sect_attrs)
1497 + nloaded * sizeof(sect_attrs->attrs[0]),
1498 sizeof(sect_attrs->grp.attrs[0]));
1499 size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]);
1500 sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
1501 if (sect_attrs == NULL)
1502 return;
1503
1504 /* Setup section attributes. */
1505 sect_attrs->grp.name = "sections";
1506 sect_attrs->grp.attrs = (void *)sect_attrs + size[0];
1507
1508 sect_attrs->nsections = 0;
1509 sattr = &sect_attrs->attrs[0];
1510 gattr = &sect_attrs->grp.attrs[0];
1511 for (i = 0; i < info->hdr->e_shnum; i++) {
1512 Elf_Shdr *sec = &info->sechdrs[i];
1513 if (sect_empty(sec))
1514 continue;
1515 sattr->address = sec->sh_addr;
1516 sattr->name = kstrdup(info->secstrings + sec->sh_name,
1517 GFP_KERNEL);
1518 if (sattr->name == NULL)
1519 goto out;
1520 sect_attrs->nsections++;
1521 sysfs_attr_init(&sattr->mattr.attr);
1522 sattr->mattr.show = module_sect_show;
1523 sattr->mattr.store = NULL;
1524 sattr->mattr.attr.name = sattr->name;
1525 sattr->mattr.attr.mode = S_IRUGO;
1526 *(gattr++) = &(sattr++)->mattr.attr;
1527 }
1528 *gattr = NULL;
1529
1530 if (sysfs_create_group(&mod->mkobj.kobj, &sect_attrs->grp))
1531 goto out;
1532
1533 mod->sect_attrs = sect_attrs;
1534 return;
1535 out:
1536 free_sect_attrs(sect_attrs);
1537}
1538
1539static void remove_sect_attrs(struct module *mod)
1540{
1541 if (mod->sect_attrs) {
1542 sysfs_remove_group(&mod->mkobj.kobj,
1543 &mod->sect_attrs->grp);
1544 /* We are positive that no one is using any sect attrs
1545 * at this point. Deallocate immediately. */
1546 free_sect_attrs(mod->sect_attrs);
1547 mod->sect_attrs = NULL;
1548 }
1549}
1550
1551/*
1552 * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
1553 */
1554
1555struct module_notes_attrs {
1556 struct kobject *dir;
1557 unsigned int notes;
1558 struct bin_attribute attrs[0];
1559};
1560
1561static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
1562 struct bin_attribute *bin_attr,
1563 char *buf, loff_t pos, size_t count)
1564{
1565 /*
1566 * The caller checked the pos and count against our size.
1567 */
1568 memcpy(buf, bin_attr->private + pos, count);
1569 return count;
1570}
1571
1572static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
1573 unsigned int i)
1574{
1575 if (notes_attrs->dir) {
1576 while (i-- > 0)
1577 sysfs_remove_bin_file(notes_attrs->dir,
1578 &notes_attrs->attrs[i]);
1579 kobject_put(notes_attrs->dir);
1580 }
1581 kfree(notes_attrs);
1582}
1583
1584static void add_notes_attrs(struct module *mod, const struct load_info *info)
1585{
1586 unsigned int notes, loaded, i;
1587 struct module_notes_attrs *notes_attrs;
1588 struct bin_attribute *nattr;
1589
1590 /* failed to create section attributes, so can't create notes */
1591 if (!mod->sect_attrs)
1592 return;
1593
1594 /* Count notes sections and allocate structures. */
1595 notes = 0;
1596 for (i = 0; i < info->hdr->e_shnum; i++)
1597 if (!sect_empty(&info->sechdrs[i]) &&
1598 (info->sechdrs[i].sh_type == SHT_NOTE))
1599 ++notes;
1600
1601 if (notes == 0)
1602 return;
1603
1604 notes_attrs = kzalloc(sizeof(*notes_attrs)
1605 + notes * sizeof(notes_attrs->attrs[0]),
1606 GFP_KERNEL);
1607 if (notes_attrs == NULL)
1608 return;
1609
1610 notes_attrs->notes = notes;
1611 nattr = &notes_attrs->attrs[0];
1612 for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
1613 if (sect_empty(&info->sechdrs[i]))
1614 continue;
1615 if (info->sechdrs[i].sh_type == SHT_NOTE) {
1616 sysfs_bin_attr_init(nattr);
1617 nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
1618 nattr->attr.mode = S_IRUGO;
1619 nattr->size = info->sechdrs[i].sh_size;
1620 nattr->private = (void *) info->sechdrs[i].sh_addr;
1621 nattr->read = module_notes_read;
1622 ++nattr;
1623 }
1624 ++loaded;
1625 }
1626
1627 notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
1628 if (!notes_attrs->dir)
1629 goto out;
1630
1631 for (i = 0; i < notes; ++i)
1632 if (sysfs_create_bin_file(notes_attrs->dir,
1633 &notes_attrs->attrs[i]))
1634 goto out;
1635
1636 mod->notes_attrs = notes_attrs;
1637 return;
1638
1639 out:
1640 free_notes_attrs(notes_attrs, i);
1641}
1642
1643static void remove_notes_attrs(struct module *mod)
1644{
1645 if (mod->notes_attrs)
1646 free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
1647}
1648
1649#else
1650
1651static inline void add_sect_attrs(struct module *mod,
1652 const struct load_info *info)
1653{
1654}
1655
1656static inline void remove_sect_attrs(struct module *mod)
1657{
1658}
1659
1660static inline void add_notes_attrs(struct module *mod,
1661 const struct load_info *info)
1662{
1663}
1664
1665static inline void remove_notes_attrs(struct module *mod)
1666{
1667}
1668#endif /* CONFIG_KALLSYMS */
1669
1670static void add_usage_links(struct module *mod)
1671{
1672#ifdef CONFIG_MODULE_UNLOAD
1673 struct module_use *use;
1674 int nowarn;
1675
1676 mutex_lock(&module_mutex);
1677 list_for_each_entry(use, &mod->target_list, target_list) {
1678 nowarn = sysfs_create_link(use->target->holders_dir,
1679 &mod->mkobj.kobj, mod->name);
1680 }
1681 mutex_unlock(&module_mutex);
1682#endif
1683}
1684
1685static void del_usage_links(struct module *mod)
1686{
1687#ifdef CONFIG_MODULE_UNLOAD
1688 struct module_use *use;
1689
1690 mutex_lock(&module_mutex);
1691 list_for_each_entry(use, &mod->target_list, target_list)
1692 sysfs_remove_link(use->target->holders_dir, mod->name);
1693 mutex_unlock(&module_mutex);
1694#endif
1695}
1696
1697static int module_add_modinfo_attrs(struct module *mod)
1698{
1699 struct module_attribute *attr;
1700 struct module_attribute *temp_attr;
1701 int error = 0;
1702 int i;
1703
1704 mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
1705 (ARRAY_SIZE(modinfo_attrs) + 1)),
1706 GFP_KERNEL);
1707 if (!mod->modinfo_attrs)
1708 return -ENOMEM;
1709
1710 temp_attr = mod->modinfo_attrs;
1711 for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
1712 if (!attr->test || attr->test(mod)) {
1713 memcpy(temp_attr, attr, sizeof(*temp_attr));
1714 sysfs_attr_init(&temp_attr->attr);
1715 error = sysfs_create_file(&mod->mkobj.kobj,
1716 &temp_attr->attr);
1717 ++temp_attr;
1718 }
1719 }
1720 return error;
1721}
1722
1723static void module_remove_modinfo_attrs(struct module *mod)
1724{
1725 struct module_attribute *attr;
1726 int i;
1727
1728 for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
1729 /* pick a field to test for end of list */
1730 if (!attr->attr.name)
1731 break;
1732 sysfs_remove_file(&mod->mkobj.kobj, &attr->attr);
1733 if (attr->free)
1734 attr->free(mod);
1735 }
1736 kfree(mod->modinfo_attrs);
1737}
1738
1739static void mod_kobject_put(struct module *mod)
1740{
1741 DECLARE_COMPLETION_ONSTACK(c);
1742 mod->mkobj.kobj_completion = &c;
1743 kobject_put(&mod->mkobj.kobj);
1744 wait_for_completion(&c);
1745}
1746
1747static int mod_sysfs_init(struct module *mod)
1748{
1749 int err;
1750 struct kobject *kobj;
1751
1752 if (!module_sysfs_initialized) {
1753 pr_err("%s: module sysfs not initialized\n", mod->name);
1754 err = -EINVAL;
1755 goto out;
1756 }
1757
1758 kobj = kset_find_obj(module_kset, mod->name);
1759 if (kobj) {
1760 pr_err("%s: module is already loaded\n", mod->name);
1761 kobject_put(kobj);
1762 err = -EINVAL;
1763 goto out;
1764 }
1765
1766 mod->mkobj.mod = mod;
1767
1768 memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
1769 mod->mkobj.kobj.kset = module_kset;
1770 err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
1771 "%s", mod->name);
1772 if (err)
1773 mod_kobject_put(mod);
1774
1775 /* delay uevent until full sysfs population */
1776out:
1777 return err;
1778}
1779
1780static int mod_sysfs_setup(struct module *mod,
1781 const struct load_info *info,
1782 struct kernel_param *kparam,
1783 unsigned int num_params)
1784{
1785 int err;
1786
1787 err = mod_sysfs_init(mod);
1788 if (err)
1789 goto out;
1790
1791 mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1792 if (!mod->holders_dir) {
1793 err = -ENOMEM;
1794 goto out_unreg;
1795 }
1796
1797 err = module_param_sysfs_setup(mod, kparam, num_params);
1798 if (err)
1799 goto out_unreg_holders;
1800
1801 err = module_add_modinfo_attrs(mod);
1802 if (err)
1803 goto out_unreg_param;
1804
1805 add_usage_links(mod);
1806 add_sect_attrs(mod, info);
1807 add_notes_attrs(mod, info);
1808
1809 kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
1810 return 0;
1811
1812out_unreg_param:
1813 module_param_sysfs_remove(mod);
1814out_unreg_holders:
1815 kobject_put(mod->holders_dir);
1816out_unreg:
1817 mod_kobject_put(mod);
1818out:
1819 return err;
1820}
1821
1822static void mod_sysfs_fini(struct module *mod)
1823{
1824 remove_notes_attrs(mod);
1825 remove_sect_attrs(mod);
1826 mod_kobject_put(mod);
1827}
1828
1829static void init_param_lock(struct module *mod)
1830{
1831 mutex_init(&mod->param_lock);
1832}
1833#else /* !CONFIG_SYSFS */
1834
1835static int mod_sysfs_setup(struct module *mod,
1836 const struct load_info *info,
1837 struct kernel_param *kparam,
1838 unsigned int num_params)
1839{
1840 return 0;
1841}
1842
1843static void mod_sysfs_fini(struct module *mod)
1844{
1845}
1846
1847static void module_remove_modinfo_attrs(struct module *mod)
1848{
1849}
1850
1851static void del_usage_links(struct module *mod)
1852{
1853}
1854
1855static void init_param_lock(struct module *mod)
1856{
1857}
1858#endif /* CONFIG_SYSFS */
1859
1860static void mod_sysfs_teardown(struct module *mod)
1861{
1862 del_usage_links(mod);
1863 module_remove_modinfo_attrs(mod);
1864 module_param_sysfs_remove(mod);
1865 kobject_put(mod->mkobj.drivers_dir);
1866 kobject_put(mod->holders_dir);
1867 mod_sysfs_fini(mod);
1868}
1869
1870#ifdef CONFIG_STRICT_MODULE_RWX
1871/*
1872 * LKM RO/NX protection: protect module's text/ro-data
1873 * from modification and any data from execution.
1874 *
1875 * General layout of module is:
1876 * [text] [read-only-data] [ro-after-init] [writable data]
1877 * text_size -----^ ^ ^ ^
1878 * ro_size ------------------------| | |
1879 * ro_after_init_size -----------------------------| |
1880 * size -----------------------------------------------------------|
1881 *
1882 * These values are always page-aligned (as is base)
1883 */
1884static void frob_text(const struct module_layout *layout,
1885 int (*set_memory)(unsigned long start, int num_pages))
1886{
1887 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1888 BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
1889 set_memory((unsigned long)layout->base,
1890 layout->text_size >> PAGE_SHIFT);
1891}
1892
1893static void frob_rodata(const struct module_layout *layout,
1894 int (*set_memory)(unsigned long start, int num_pages))
1895{
1896 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1897 BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
1898 BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
1899 set_memory((unsigned long)layout->base + layout->text_size,
1900 (layout->ro_size - layout->text_size) >> PAGE_SHIFT);
1901}
1902
1903static void frob_ro_after_init(const struct module_layout *layout,
1904 int (*set_memory)(unsigned long start, int num_pages))
1905{
1906 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1907 BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
1908 BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
1909 set_memory((unsigned long)layout->base + layout->ro_size,
1910 (layout->ro_after_init_size - layout->ro_size) >> PAGE_SHIFT);
1911}
1912
1913static void frob_writable_data(const struct module_layout *layout,
1914 int (*set_memory)(unsigned long start, int num_pages))
1915{
1916 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1917 BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
1918 BUG_ON((unsigned long)layout->size & (PAGE_SIZE-1));
1919 set_memory((unsigned long)layout->base + layout->ro_after_init_size,
1920 (layout->size - layout->ro_after_init_size) >> PAGE_SHIFT);
1921}
1922
1923/* livepatching wants to disable read-only so it can frob module. */
1924void module_disable_ro(const struct module *mod)
1925{
1926 if (!rodata_enabled)
1927 return;
1928
1929 frob_text(&mod->core_layout, set_memory_rw);
1930 frob_rodata(&mod->core_layout, set_memory_rw);
1931 frob_ro_after_init(&mod->core_layout, set_memory_rw);
1932 frob_text(&mod->init_layout, set_memory_rw);
1933 frob_rodata(&mod->init_layout, set_memory_rw);
1934}
1935
1936void module_enable_ro(const struct module *mod, bool after_init)
1937{
1938 if (!rodata_enabled)
1939 return;
1940
1941 frob_text(&mod->core_layout, set_memory_ro);
1942 frob_rodata(&mod->core_layout, set_memory_ro);
1943 frob_text(&mod->init_layout, set_memory_ro);
1944 frob_rodata(&mod->init_layout, set_memory_ro);
1945
1946 if (after_init)
1947 frob_ro_after_init(&mod->core_layout, set_memory_ro);
1948}
1949
1950static void module_enable_nx(const struct module *mod)
1951{
1952 frob_rodata(&mod->core_layout, set_memory_nx);
1953 frob_ro_after_init(&mod->core_layout, set_memory_nx);
1954 frob_writable_data(&mod->core_layout, set_memory_nx);
1955 frob_rodata(&mod->init_layout, set_memory_nx);
1956 frob_writable_data(&mod->init_layout, set_memory_nx);
1957}
1958
1959static void module_disable_nx(const struct module *mod)
1960{
1961 frob_rodata(&mod->core_layout, set_memory_x);
1962 frob_ro_after_init(&mod->core_layout, set_memory_x);
1963 frob_writable_data(&mod->core_layout, set_memory_x);
1964 frob_rodata(&mod->init_layout, set_memory_x);
1965 frob_writable_data(&mod->init_layout, set_memory_x);
1966}
1967
1968/* Iterate through all modules and set each module's text as RW */
1969void set_all_modules_text_rw(void)
1970{
1971 struct module *mod;
1972
1973 if (!rodata_enabled)
1974 return;
1975
1976 mutex_lock(&module_mutex);
1977 list_for_each_entry_rcu(mod, &modules, list) {
1978 if (mod->state == MODULE_STATE_UNFORMED)
1979 continue;
1980
1981 frob_text(&mod->core_layout, set_memory_rw);
1982 frob_text(&mod->init_layout, set_memory_rw);
1983 }
1984 mutex_unlock(&module_mutex);
1985}
1986
1987/* Iterate through all modules and set each module's text as RO */
1988void set_all_modules_text_ro(void)
1989{
1990 struct module *mod;
1991
1992 if (!rodata_enabled)
1993 return;
1994
1995 mutex_lock(&module_mutex);
1996 list_for_each_entry_rcu(mod, &modules, list) {
1997 /*
1998 * Ignore going modules since it's possible that ro
1999 * protection has already been disabled, otherwise we'll
2000 * run into protection faults at module deallocation.
2001 */
2002 if (mod->state == MODULE_STATE_UNFORMED ||
2003 mod->state == MODULE_STATE_GOING)
2004 continue;
2005
2006 frob_text(&mod->core_layout, set_memory_ro);
2007 frob_text(&mod->init_layout, set_memory_ro);
2008 }
2009 mutex_unlock(&module_mutex);
2010}
2011
2012static void disable_ro_nx(const struct module_layout *layout)
2013{
2014 if (rodata_enabled) {
2015 frob_text(layout, set_memory_rw);
2016 frob_rodata(layout, set_memory_rw);
2017 frob_ro_after_init(layout, set_memory_rw);
2018 }
2019 frob_rodata(layout, set_memory_x);
2020 frob_ro_after_init(layout, set_memory_x);
2021 frob_writable_data(layout, set_memory_x);
2022}
2023
2024#else
2025static void disable_ro_nx(const struct module_layout *layout) { }
2026static void module_enable_nx(const struct module *mod) { }
2027static void module_disable_nx(const struct module *mod) { }
2028#endif
2029
2030#ifdef CONFIG_LIVEPATCH
2031/*
2032 * Persist Elf information about a module. Copy the Elf header,
2033 * section header table, section string table, and symtab section
2034 * index from info to mod->klp_info.
2035 */
2036static int copy_module_elf(struct module *mod, struct load_info *info)
2037{
2038 unsigned int size, symndx;
2039 int ret;
2040
2041 size = sizeof(*mod->klp_info);
2042 mod->klp_info = kmalloc(size, GFP_KERNEL);
2043 if (mod->klp_info == NULL)
2044 return -ENOMEM;
2045
2046 /* Elf header */
2047 size = sizeof(mod->klp_info->hdr);
2048 memcpy(&mod->klp_info->hdr, info->hdr, size);
2049
2050 /* Elf section header table */
2051 size = sizeof(*info->sechdrs) * info->hdr->e_shnum;
2052 mod->klp_info->sechdrs = kmalloc(size, GFP_KERNEL);
2053 if (mod->klp_info->sechdrs == NULL) {
2054 ret = -ENOMEM;
2055 goto free_info;
2056 }
2057 memcpy(mod->klp_info->sechdrs, info->sechdrs, size);
2058
2059 /* Elf section name string table */
2060 size = info->sechdrs[info->hdr->e_shstrndx].sh_size;
2061 mod->klp_info->secstrings = kmalloc(size, GFP_KERNEL);
2062 if (mod->klp_info->secstrings == NULL) {
2063 ret = -ENOMEM;
2064 goto free_sechdrs;
2065 }
2066 memcpy(mod->klp_info->secstrings, info->secstrings, size);
2067
2068 /* Elf symbol section index */
2069 symndx = info->index.sym;
2070 mod->klp_info->symndx = symndx;
2071
2072 /*
2073 * For livepatch modules, core_kallsyms.symtab is a complete
2074 * copy of the original symbol table. Adjust sh_addr to point
2075 * to core_kallsyms.symtab since the copy of the symtab in module
2076 * init memory is freed at the end of do_init_module().
2077 */
2078 mod->klp_info->sechdrs[symndx].sh_addr = \
2079 (unsigned long) mod->core_kallsyms.symtab;
2080
2081 return 0;
2082
2083free_sechdrs:
2084 kfree(mod->klp_info->sechdrs);
2085free_info:
2086 kfree(mod->klp_info);
2087 return ret;
2088}
2089
2090static void free_module_elf(struct module *mod)
2091{
2092 kfree(mod->klp_info->sechdrs);
2093 kfree(mod->klp_info->secstrings);
2094 kfree(mod->klp_info);
2095}
2096#else /* !CONFIG_LIVEPATCH */
2097static int copy_module_elf(struct module *mod, struct load_info *info)
2098{
2099 return 0;
2100}
2101
2102static void free_module_elf(struct module *mod)
2103{
2104}
2105#endif /* CONFIG_LIVEPATCH */
2106
2107void __weak module_memfree(void *module_region)
2108{
2109 vfree(module_region);
2110}
2111
2112void __weak module_arch_cleanup(struct module *mod)
2113{
2114}
2115
2116void __weak module_arch_freeing_init(struct module *mod)
2117{
2118}
2119
2120/* Free a module, remove from lists, etc. */
2121static void free_module(struct module *mod)
2122{
2123 trace_module_free(mod);
2124
2125 mod_sysfs_teardown(mod);
2126
2127 /* We leave it in list to prevent duplicate loads, but make sure
2128 * that noone uses it while it's being deconstructed. */
2129 mutex_lock(&module_mutex);
2130 mod->state = MODULE_STATE_UNFORMED;
2131 mutex_unlock(&module_mutex);
2132
2133 /* Remove dynamic debug info */
2134 ddebug_remove_module(mod->name);
2135
2136 /* Arch-specific cleanup. */
2137 module_arch_cleanup(mod);
2138
2139 /* Module unload stuff */
2140 module_unload_free(mod);
2141
2142 /* Free any allocated parameters. */
2143 destroy_params(mod->kp, mod->num_kp);
2144
2145 if (is_livepatch_module(mod))
2146 free_module_elf(mod);
2147
2148 /* Now we can delete it from the lists */
2149 mutex_lock(&module_mutex);
2150 /* Unlink carefully: kallsyms could be walking list. */
2151 list_del_rcu(&mod->list);
2152 mod_tree_remove(mod);
2153 /* Remove this module from bug list, this uses list_del_rcu */
2154 module_bug_cleanup(mod);
2155 /* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */
2156 synchronize_sched();
2157 mutex_unlock(&module_mutex);
2158
2159 /* This may be empty, but that's OK */
2160 disable_ro_nx(&mod->init_layout);
2161 module_arch_freeing_init(mod);
2162 module_memfree(mod->init_layout.base);
2163 kfree(mod->args);
2164 percpu_modfree(mod);
2165
2166 /* Free lock-classes; relies on the preceding sync_rcu(). */
2167 lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
2168
2169 /* Finally, free the core (containing the module structure) */
2170 disable_ro_nx(&mod->core_layout);
2171 module_memfree(mod->core_layout.base);
2172
2173#ifdef CONFIG_MPU
2174 update_protections(current->mm);
2175#endif
2176}
2177
2178void *__symbol_get(const char *symbol)
2179{
2180 struct module *owner;
2181 const struct kernel_symbol *sym;
2182
2183 preempt_disable();
2184 sym = find_symbol(symbol, &owner, NULL, true, true);
2185 if (sym && strong_try_module_get(owner))
2186 sym = NULL;
2187 preempt_enable();
2188
2189 return sym ? (void *)sym->value : NULL;
2190}
2191EXPORT_SYMBOL_GPL(__symbol_get);
2192
2193/*
2194 * Ensure that an exported symbol [global namespace] does not already exist
2195 * in the kernel or in some other module's exported symbol table.
2196 *
2197 * You must hold the module_mutex.
2198 */
2199static int verify_export_symbols(struct module *mod)
2200{
2201 unsigned int i;
2202 struct module *owner;
2203 const struct kernel_symbol *s;
2204 struct {
2205 const struct kernel_symbol *sym;
2206 unsigned int num;
2207 } arr[] = {
2208 { mod->syms, mod->num_syms },
2209 { mod->gpl_syms, mod->num_gpl_syms },
2210 { mod->gpl_future_syms, mod->num_gpl_future_syms },
2211#ifdef CONFIG_UNUSED_SYMBOLS
2212 { mod->unused_syms, mod->num_unused_syms },
2213 { mod->unused_gpl_syms, mod->num_unused_gpl_syms },
2214#endif
2215 };
2216
2217 for (i = 0; i < ARRAY_SIZE(arr); i++) {
2218 for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
2219 if (find_symbol(s->name, &owner, NULL, true, false)) {
2220 pr_err("%s: exports duplicate symbol %s"
2221 " (owned by %s)\n",
2222 mod->name, s->name, module_name(owner));
2223 return -ENOEXEC;
2224 }
2225 }
2226 }
2227 return 0;
2228}
2229
2230/* Change all symbols so that st_value encodes the pointer directly. */
2231static int simplify_symbols(struct module *mod, const struct load_info *info)
2232{
2233 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2234 Elf_Sym *sym = (void *)symsec->sh_addr;
2235 unsigned long secbase;
2236 unsigned int i;
2237 int ret = 0;
2238 const struct kernel_symbol *ksym;
2239
2240 for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
2241 const char *name = info->strtab + sym[i].st_name;
2242
2243 switch (sym[i].st_shndx) {
2244 case SHN_COMMON:
2245 /* Ignore common symbols */
2246 if (!strncmp(name, "__gnu_lto", 9))
2247 break;
2248
2249 /* We compiled with -fno-common. These are not
2250 supposed to happen. */
2251 pr_debug("Common symbol: %s\n", name);
2252 pr_warn("%s: please compile with -fno-common\n",
2253 mod->name);
2254 ret = -ENOEXEC;
2255 break;
2256
2257 case SHN_ABS:
2258 /* Don't need to do anything */
2259 pr_debug("Absolute symbol: 0x%08lx\n",
2260 (long)sym[i].st_value);
2261 break;
2262
2263 case SHN_LIVEPATCH:
2264 /* Livepatch symbols are resolved by livepatch */
2265 break;
2266
2267 case SHN_UNDEF:
2268 ksym = resolve_symbol_wait(mod, info, name);
2269 /* Ok if resolved. */
2270 if (ksym && !IS_ERR(ksym)) {
2271 sym[i].st_value = ksym->value;
2272 break;
2273 }
2274
2275 /* Ok if weak. */
2276 if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
2277 break;
2278
2279 pr_warn("%s: Unknown symbol %s (err %li)\n",
2280 mod->name, name, PTR_ERR(ksym));
2281 ret = PTR_ERR(ksym) ?: -ENOENT;
2282 break;
2283
2284 default:
2285 /* Divert to percpu allocation if a percpu var. */
2286 if (sym[i].st_shndx == info->index.pcpu)
2287 secbase = (unsigned long)mod_percpu(mod);
2288 else
2289 secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
2290 sym[i].st_value += secbase;
2291 break;
2292 }
2293 }
2294
2295 return ret;
2296}
2297
2298static int apply_relocations(struct module *mod, const struct load_info *info)
2299{
2300 unsigned int i;
2301 int err = 0;
2302
2303 /* Now do relocations. */
2304 for (i = 1; i < info->hdr->e_shnum; i++) {
2305 unsigned int infosec = info->sechdrs[i].sh_info;
2306
2307 /* Not a valid relocation section? */
2308 if (infosec >= info->hdr->e_shnum)
2309 continue;
2310
2311 /* Don't bother with non-allocated sections */
2312 if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
2313 continue;
2314
2315 /* Livepatch relocation sections are applied by livepatch */
2316 if (info->sechdrs[i].sh_flags & SHF_RELA_LIVEPATCH)
2317 continue;
2318
2319 if (info->sechdrs[i].sh_type == SHT_REL)
2320 err = apply_relocate(info->sechdrs, info->strtab,
2321 info->index.sym, i, mod);
2322 else if (info->sechdrs[i].sh_type == SHT_RELA)
2323 err = apply_relocate_add(info->sechdrs, info->strtab,
2324 info->index.sym, i, mod);
2325 if (err < 0)
2326 break;
2327 }
2328 return err;
2329}
2330
2331/* Additional bytes needed by arch in front of individual sections */
2332unsigned int __weak arch_mod_section_prepend(struct module *mod,
2333 unsigned int section)
2334{
2335 /* default implementation just returns zero */
2336 return 0;
2337}
2338
2339/* Update size with this section: return offset. */
2340static long get_offset(struct module *mod, unsigned int *size,
2341 Elf_Shdr *sechdr, unsigned int section)
2342{
2343 long ret;
2344
2345 *size += arch_mod_section_prepend(mod, section);
2346 ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
2347 *size = ret + sechdr->sh_size;
2348 return ret;
2349}
2350
2351/* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
2352 might -- code, read-only data, read-write data, small data. Tally
2353 sizes, and place the offsets into sh_entsize fields: high bit means it
2354 belongs in init. */
2355static void layout_sections(struct module *mod, struct load_info *info)
2356{
2357 static unsigned long const masks[][2] = {
2358 /* NOTE: all executable code must be the first section
2359 * in this array; otherwise modify the text_size
2360 * finder in the two loops below */
2361 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
2362 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
2363 { SHF_RO_AFTER_INIT | SHF_ALLOC, ARCH_SHF_SMALL },
2364 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
2365 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
2366 };
2367 unsigned int m, i;
2368
2369 for (i = 0; i < info->hdr->e_shnum; i++)
2370 info->sechdrs[i].sh_entsize = ~0UL;
2371
2372 pr_debug("Core section allocation order:\n");
2373 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2374 for (i = 0; i < info->hdr->e_shnum; ++i) {
2375 Elf_Shdr *s = &info->sechdrs[i];
2376 const char *sname = info->secstrings + s->sh_name;
2377
2378 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2379 || (s->sh_flags & masks[m][1])
2380 || s->sh_entsize != ~0UL
2381 || strstarts(sname, ".init"))
2382 continue;
2383 s->sh_entsize = get_offset(mod, &mod->core_layout.size, s, i);
2384 pr_debug("\t%s\n", sname);
2385 }
2386 switch (m) {
2387 case 0: /* executable */
2388 mod->core_layout.size = debug_align(mod->core_layout.size);
2389 mod->core_layout.text_size = mod->core_layout.size;
2390 break;
2391 case 1: /* RO: text and ro-data */
2392 mod->core_layout.size = debug_align(mod->core_layout.size);
2393 mod->core_layout.ro_size = mod->core_layout.size;
2394 break;
2395 case 2: /* RO after init */
2396 mod->core_layout.size = debug_align(mod->core_layout.size);
2397 mod->core_layout.ro_after_init_size = mod->core_layout.size;
2398 break;
2399 case 4: /* whole core */
2400 mod->core_layout.size = debug_align(mod->core_layout.size);
2401 break;
2402 }
2403 }
2404
2405 pr_debug("Init section allocation order:\n");
2406 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2407 for (i = 0; i < info->hdr->e_shnum; ++i) {
2408 Elf_Shdr *s = &info->sechdrs[i];
2409 const char *sname = info->secstrings + s->sh_name;
2410
2411 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2412 || (s->sh_flags & masks[m][1])
2413 || s->sh_entsize != ~0UL
2414 || !strstarts(sname, ".init"))
2415 continue;
2416 s->sh_entsize = (get_offset(mod, &mod->init_layout.size, s, i)
2417 | INIT_OFFSET_MASK);
2418 pr_debug("\t%s\n", sname);
2419 }
2420 switch (m) {
2421 case 0: /* executable */
2422 mod->init_layout.size = debug_align(mod->init_layout.size);
2423 mod->init_layout.text_size = mod->init_layout.size;
2424 break;
2425 case 1: /* RO: text and ro-data */
2426 mod->init_layout.size = debug_align(mod->init_layout.size);
2427 mod->init_layout.ro_size = mod->init_layout.size;
2428 break;
2429 case 2:
2430 /*
2431 * RO after init doesn't apply to init_layout (only
2432 * core_layout), so it just takes the value of ro_size.
2433 */
2434 mod->init_layout.ro_after_init_size = mod->init_layout.ro_size;
2435 break;
2436 case 4: /* whole init */
2437 mod->init_layout.size = debug_align(mod->init_layout.size);
2438 break;
2439 }
2440 }
2441}
2442
2443static void set_license(struct module *mod, const char *license)
2444{
2445 if (!license)
2446 license = "unspecified";
2447
2448 if (!license_is_gpl_compatible(license)) {
2449 if (!test_taint(TAINT_PROPRIETARY_MODULE))
2450 pr_warn("%s: module license '%s' taints kernel.\n",
2451 mod->name, license);
2452 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2453 LOCKDEP_NOW_UNRELIABLE);
2454 }
2455}
2456
2457/* Parse tag=value strings from .modinfo section */
2458static char *next_string(char *string, unsigned long *secsize)
2459{
2460 /* Skip non-zero chars */
2461 while (string[0]) {
2462 string++;
2463 if ((*secsize)-- <= 1)
2464 return NULL;
2465 }
2466
2467 /* Skip any zero padding. */
2468 while (!string[0]) {
2469 string++;
2470 if ((*secsize)-- <= 1)
2471 return NULL;
2472 }
2473 return string;
2474}
2475
2476static char *get_modinfo(struct load_info *info, const char *tag)
2477{
2478 char *p;
2479 unsigned int taglen = strlen(tag);
2480 Elf_Shdr *infosec = &info->sechdrs[info->index.info];
2481 unsigned long size = infosec->sh_size;
2482
2483 for (p = (char *)infosec->sh_addr; p; p = next_string(p, &size)) {
2484 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
2485 return p + taglen + 1;
2486 }
2487 return NULL;
2488}
2489
2490static void setup_modinfo(struct module *mod, struct load_info *info)
2491{
2492 struct module_attribute *attr;
2493 int i;
2494
2495 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2496 if (attr->setup)
2497 attr->setup(mod, get_modinfo(info, attr->attr.name));
2498 }
2499}
2500
2501static void free_modinfo(struct module *mod)
2502{
2503 struct module_attribute *attr;
2504 int i;
2505
2506 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2507 if (attr->free)
2508 attr->free(mod);
2509 }
2510}
2511
2512#ifdef CONFIG_KALLSYMS
2513
2514/* lookup symbol in given range of kernel_symbols */
2515static const struct kernel_symbol *lookup_symbol(const char *name,
2516 const struct kernel_symbol *start,
2517 const struct kernel_symbol *stop)
2518{
2519 return bsearch(name, start, stop - start,
2520 sizeof(struct kernel_symbol), cmp_name);
2521}
2522
2523static int is_exported(const char *name, unsigned long value,
2524 const struct module *mod)
2525{
2526 const struct kernel_symbol *ks;
2527 if (!mod)
2528 ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
2529 else
2530 ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
2531 return ks != NULL && ks->value == value;
2532}
2533
2534/* As per nm */
2535static char elf_type(const Elf_Sym *sym, const struct load_info *info)
2536{
2537 const Elf_Shdr *sechdrs = info->sechdrs;
2538
2539 if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
2540 if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
2541 return 'v';
2542 else
2543 return 'w';
2544 }
2545 if (sym->st_shndx == SHN_UNDEF)
2546 return 'U';
2547 if (sym->st_shndx == SHN_ABS || sym->st_shndx == info->index.pcpu)
2548 return 'a';
2549 if (sym->st_shndx >= SHN_LORESERVE)
2550 return '?';
2551 if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
2552 return 't';
2553 if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
2554 && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
2555 if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
2556 return 'r';
2557 else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2558 return 'g';
2559 else
2560 return 'd';
2561 }
2562 if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
2563 if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2564 return 's';
2565 else
2566 return 'b';
2567 }
2568 if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
2569 ".debug")) {
2570 return 'n';
2571 }
2572 return '?';
2573}
2574
2575static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
2576 unsigned int shnum, unsigned int pcpundx)
2577{
2578 const Elf_Shdr *sec;
2579
2580 if (src->st_shndx == SHN_UNDEF
2581 || src->st_shndx >= shnum
2582 || !src->st_name)
2583 return false;
2584
2585#ifdef CONFIG_KALLSYMS_ALL
2586 if (src->st_shndx == pcpundx)
2587 return true;
2588#endif
2589
2590 sec = sechdrs + src->st_shndx;
2591 if (!(sec->sh_flags & SHF_ALLOC)
2592#ifndef CONFIG_KALLSYMS_ALL
2593 || !(sec->sh_flags & SHF_EXECINSTR)
2594#endif
2595 || (sec->sh_entsize & INIT_OFFSET_MASK))
2596 return false;
2597
2598 return true;
2599}
2600
2601/*
2602 * We only allocate and copy the strings needed by the parts of symtab
2603 * we keep. This is simple, but has the effect of making multiple
2604 * copies of duplicates. We could be more sophisticated, see
2605 * linux-kernel thread starting with
2606 * <73defb5e4bca04a6431392cc341112b1@localhost>.
2607 */
2608static void layout_symtab(struct module *mod, struct load_info *info)
2609{
2610 Elf_Shdr *symsect = info->sechdrs + info->index.sym;
2611 Elf_Shdr *strsect = info->sechdrs + info->index.str;
2612 const Elf_Sym *src;
2613 unsigned int i, nsrc, ndst, strtab_size = 0;
2614
2615 /* Put symbol section at end of init part of module. */
2616 symsect->sh_flags |= SHF_ALLOC;
2617 symsect->sh_entsize = get_offset(mod, &mod->init_layout.size, symsect,
2618 info->index.sym) | INIT_OFFSET_MASK;
2619 pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
2620
2621 src = (void *)info->hdr + symsect->sh_offset;
2622 nsrc = symsect->sh_size / sizeof(*src);
2623
2624 /* Compute total space required for the core symbols' strtab. */
2625 for (ndst = i = 0; i < nsrc; i++) {
2626 if (i == 0 || is_livepatch_module(mod) ||
2627 is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
2628 info->index.pcpu)) {
2629 strtab_size += strlen(&info->strtab[src[i].st_name])+1;
2630 ndst++;
2631 }
2632 }
2633
2634 /* Append room for core symbols at end of core part. */
2635 info->symoffs = ALIGN(mod->core_layout.size, symsect->sh_addralign ?: 1);
2636 info->stroffs = mod->core_layout.size = info->symoffs + ndst * sizeof(Elf_Sym);
2637 mod->core_layout.size += strtab_size;
2638 mod->core_layout.size = debug_align(mod->core_layout.size);
2639
2640 /* Put string table section at end of init part of module. */
2641 strsect->sh_flags |= SHF_ALLOC;
2642 strsect->sh_entsize = get_offset(mod, &mod->init_layout.size, strsect,
2643 info->index.str) | INIT_OFFSET_MASK;
2644 pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
2645
2646 /* We'll tack temporary mod_kallsyms on the end. */
2647 mod->init_layout.size = ALIGN(mod->init_layout.size,
2648 __alignof__(struct mod_kallsyms));
2649 info->mod_kallsyms_init_off = mod->init_layout.size;
2650 mod->init_layout.size += sizeof(struct mod_kallsyms);
2651 mod->init_layout.size = debug_align(mod->init_layout.size);
2652}
2653
2654/*
2655 * We use the full symtab and strtab which layout_symtab arranged to
2656 * be appended to the init section. Later we switch to the cut-down
2657 * core-only ones.
2658 */
2659static void add_kallsyms(struct module *mod, const struct load_info *info)
2660{
2661 unsigned int i, ndst;
2662 const Elf_Sym *src;
2663 Elf_Sym *dst;
2664 char *s;
2665 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2666
2667 /* Set up to point into init section. */
2668 mod->kallsyms = mod->init_layout.base + info->mod_kallsyms_init_off;
2669
2670 mod->kallsyms->symtab = (void *)symsec->sh_addr;
2671 mod->kallsyms->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
2672 /* Make sure we get permanent strtab: don't use info->strtab. */
2673 mod->kallsyms->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
2674
2675 /* Set types up while we still have access to sections. */
2676 for (i = 0; i < mod->kallsyms->num_symtab; i++)
2677 mod->kallsyms->symtab[i].st_info
2678 = elf_type(&mod->kallsyms->symtab[i], info);
2679
2680 /* Now populate the cut down core kallsyms for after init. */
2681 mod->core_kallsyms.symtab = dst = mod->core_layout.base + info->symoffs;
2682 mod->core_kallsyms.strtab = s = mod->core_layout.base + info->stroffs;
2683 src = mod->kallsyms->symtab;
2684 for (ndst = i = 0; i < mod->kallsyms->num_symtab; i++) {
2685 if (i == 0 || is_livepatch_module(mod) ||
2686 is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
2687 info->index.pcpu)) {
2688 dst[ndst] = src[i];
2689 dst[ndst++].st_name = s - mod->core_kallsyms.strtab;
2690 s += strlcpy(s, &mod->kallsyms->strtab[src[i].st_name],
2691 KSYM_NAME_LEN) + 1;
2692 }
2693 }
2694 mod->core_kallsyms.num_symtab = ndst;
2695}
2696#else
2697static inline void layout_symtab(struct module *mod, struct load_info *info)
2698{
2699}
2700
2701static void add_kallsyms(struct module *mod, const struct load_info *info)
2702{
2703}
2704#endif /* CONFIG_KALLSYMS */
2705
2706static void dynamic_debug_setup(struct _ddebug *debug, unsigned int num)
2707{
2708 if (!debug)
2709 return;
2710#ifdef CONFIG_DYNAMIC_DEBUG
2711 if (ddebug_add_module(debug, num, debug->modname))
2712 pr_err("dynamic debug error adding module: %s\n",
2713 debug->modname);
2714#endif
2715}
2716
2717static void dynamic_debug_remove(struct _ddebug *debug)
2718{
2719 if (debug)
2720 ddebug_remove_module(debug->modname);
2721}
2722
2723void * __weak module_alloc(unsigned long size)
2724{
2725 return vmalloc_exec(size);
2726}
2727
2728#ifdef CONFIG_DEBUG_KMEMLEAK
2729static void kmemleak_load_module(const struct module *mod,
2730 const struct load_info *info)
2731{
2732 unsigned int i;
2733
2734 /* only scan the sections containing data */
2735 kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
2736
2737 for (i = 1; i < info->hdr->e_shnum; i++) {
2738 /* Scan all writable sections that's not executable */
2739 if (!(info->sechdrs[i].sh_flags & SHF_ALLOC) ||
2740 !(info->sechdrs[i].sh_flags & SHF_WRITE) ||
2741 (info->sechdrs[i].sh_flags & SHF_EXECINSTR))
2742 continue;
2743
2744 kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
2745 info->sechdrs[i].sh_size, GFP_KERNEL);
2746 }
2747}
2748#else
2749static inline void kmemleak_load_module(const struct module *mod,
2750 const struct load_info *info)
2751{
2752}
2753#endif
2754
2755#ifdef CONFIG_MODULE_SIG
2756static int module_sig_check(struct load_info *info, int flags)
2757{
2758 int err = -ENOKEY;
2759 const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
2760 const void *mod = info->hdr;
2761
2762 /*
2763 * Require flags == 0, as a module with version information
2764 * removed is no longer the module that was signed
2765 */
2766 if (flags == 0 &&
2767 info->len > markerlen &&
2768 memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
2769 /* We truncate the module to discard the signature */
2770 info->len -= markerlen;
2771 err = mod_verify_sig(mod, &info->len);
2772 }
2773
2774 if (!err) {
2775 info->sig_ok = true;
2776 return 0;
2777 }
2778
2779 /* Not having a signature is only an error if we're strict. */
2780 if (err == -ENOKEY && !sig_enforce)
2781 err = 0;
2782
2783 return err;
2784}
2785#else /* !CONFIG_MODULE_SIG */
2786static int module_sig_check(struct load_info *info, int flags)
2787{
2788 return 0;
2789}
2790#endif /* !CONFIG_MODULE_SIG */
2791
2792/* Sanity checks against invalid binaries, wrong arch, weird elf version. */
2793static int elf_header_check(struct load_info *info)
2794{
2795 if (info->len < sizeof(*(info->hdr)))
2796 return -ENOEXEC;
2797
2798 if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0
2799 || info->hdr->e_type != ET_REL
2800 || !elf_check_arch(info->hdr)
2801 || info->hdr->e_shentsize != sizeof(Elf_Shdr))
2802 return -ENOEXEC;
2803
2804 if (info->hdr->e_shoff >= info->len
2805 || (info->hdr->e_shnum * sizeof(Elf_Shdr) >
2806 info->len - info->hdr->e_shoff))
2807 return -ENOEXEC;
2808
2809 return 0;
2810}
2811
2812#define COPY_CHUNK_SIZE (16*PAGE_SIZE)
2813
2814static int copy_chunked_from_user(void *dst, const void __user *usrc, unsigned long len)
2815{
2816 do {
2817 unsigned long n = min(len, COPY_CHUNK_SIZE);
2818
2819 if (copy_from_user(dst, usrc, n) != 0)
2820 return -EFAULT;
2821 cond_resched();
2822 dst += n;
2823 usrc += n;
2824 len -= n;
2825 } while (len);
2826 return 0;
2827}
2828
2829#ifdef CONFIG_LIVEPATCH
2830static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
2831{
2832 if (get_modinfo(info, "livepatch")) {
2833 mod->klp = true;
2834 add_taint_module(mod, TAINT_LIVEPATCH, LOCKDEP_STILL_OK);
2835 pr_notice_once("%s: tainting kernel with TAINT_LIVEPATCH\n",
2836 mod->name);
2837 }
2838
2839 return 0;
2840}
2841#else /* !CONFIG_LIVEPATCH */
2842static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
2843{
2844 if (get_modinfo(info, "livepatch")) {
2845 pr_err("%s: module is marked as livepatch module, but livepatch support is disabled",
2846 mod->name);
2847 return -ENOEXEC;
2848 }
2849
2850 return 0;
2851}
2852#endif /* CONFIG_LIVEPATCH */
2853
2854/* Sets info->hdr and info->len. */
2855static int copy_module_from_user(const void __user *umod, unsigned long len,
2856 struct load_info *info)
2857{
2858 int err;
2859
2860 info->len = len;
2861 if (info->len < sizeof(*(info->hdr)))
2862 return -ENOEXEC;
2863
2864 err = security_kernel_read_file(NULL, READING_MODULE);
2865 if (err)
2866 return err;
2867
2868 /* Suck in entire file: we'll want most of it. */
2869 info->hdr = __vmalloc(info->len,
2870 GFP_KERNEL | __GFP_NOWARN, PAGE_KERNEL);
2871 if (!info->hdr)
2872 return -ENOMEM;
2873
2874 if (copy_chunked_from_user(info->hdr, umod, info->len) != 0) {
2875 vfree(info->hdr);
2876 return -EFAULT;
2877 }
2878
2879 return 0;
2880}
2881
2882static void free_copy(struct load_info *info)
2883{
2884 vfree(info->hdr);
2885}
2886
2887static int rewrite_section_headers(struct load_info *info, int flags)
2888{
2889 unsigned int i;
2890
2891 /* This should always be true, but let's be sure. */
2892 info->sechdrs[0].sh_addr = 0;
2893
2894 for (i = 1; i < info->hdr->e_shnum; i++) {
2895 Elf_Shdr *shdr = &info->sechdrs[i];
2896 if (shdr->sh_type != SHT_NOBITS
2897 && info->len < shdr->sh_offset + shdr->sh_size) {
2898 pr_err("Module len %lu truncated\n", info->len);
2899 return -ENOEXEC;
2900 }
2901
2902 /* Mark all sections sh_addr with their address in the
2903 temporary image. */
2904 shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
2905
2906#ifndef CONFIG_MODULE_UNLOAD
2907 /* Don't load .exit sections */
2908 if (strstarts(info->secstrings+shdr->sh_name, ".exit"))
2909 shdr->sh_flags &= ~(unsigned long)SHF_ALLOC;
2910#endif
2911 }
2912
2913 /* Track but don't keep modinfo and version sections. */
2914 if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
2915 info->index.vers = 0; /* Pretend no __versions section! */
2916 else
2917 info->index.vers = find_sec(info, "__versions");
2918 info->index.info = find_sec(info, ".modinfo");
2919 info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
2920 info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
2921 return 0;
2922}
2923
2924/*
2925 * Set up our basic convenience variables (pointers to section headers,
2926 * search for module section index etc), and do some basic section
2927 * verification.
2928 *
2929 * Return the temporary module pointer (we'll replace it with the final
2930 * one when we move the module sections around).
2931 */
2932static struct module *setup_load_info(struct load_info *info, int flags)
2933{
2934 unsigned int i;
2935 int err;
2936 struct module *mod;
2937
2938 /* Set up the convenience variables */
2939 info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
2940 info->secstrings = (void *)info->hdr
2941 + info->sechdrs[info->hdr->e_shstrndx].sh_offset;
2942
2943 err = rewrite_section_headers(info, flags);
2944 if (err)
2945 return ERR_PTR(err);
2946
2947 /* Find internal symbols and strings. */
2948 for (i = 1; i < info->hdr->e_shnum; i++) {
2949 if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
2950 info->index.sym = i;
2951 info->index.str = info->sechdrs[i].sh_link;
2952 info->strtab = (char *)info->hdr
2953 + info->sechdrs[info->index.str].sh_offset;
2954 break;
2955 }
2956 }
2957
2958 info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
2959 if (!info->index.mod) {
2960 pr_warn("No module found in object\n");
2961 return ERR_PTR(-ENOEXEC);
2962 }
2963 /* This is temporary: point mod into copy of data. */
2964 mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2965
2966 if (info->index.sym == 0) {
2967 pr_warn("%s: module has no symbols (stripped?)\n", mod->name);
2968 return ERR_PTR(-ENOEXEC);
2969 }
2970
2971 info->index.pcpu = find_pcpusec(info);
2972
2973 /* Check module struct version now, before we try to use module. */
2974 if (!check_modstruct_version(info->sechdrs, info->index.vers, mod))
2975 return ERR_PTR(-ENOEXEC);
2976
2977 return mod;
2978}
2979
2980static int check_modinfo(struct module *mod, struct load_info *info, int flags)
2981{
2982 const char *modmagic = get_modinfo(info, "vermagic");
2983 int err;
2984
2985 if (flags & MODULE_INIT_IGNORE_VERMAGIC)
2986 modmagic = NULL;
2987
2988 /* This is allowed: modprobe --force will invalidate it. */
2989 if (!modmagic) {
2990 err = try_to_force_load(mod, "bad vermagic");
2991 if (err)
2992 return err;
2993 } else if (!same_magic(modmagic, vermagic, info->index.vers)) {
2994 pr_err("%s: version magic '%s' should be '%s'\n",
2995 mod->name, modmagic, vermagic);
2996 return -ENOEXEC;
2997 }
2998
2999 if (!get_modinfo(info, "intree")) {
3000 if (!test_taint(TAINT_OOT_MODULE))
3001 pr_warn("%s: loading out-of-tree module taints kernel.\n",
3002 mod->name);
3003 add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
3004 }
3005
3006 if (get_modinfo(info, "staging")) {
3007 add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
3008 pr_warn("%s: module is from the staging directory, the quality "
3009 "is unknown, you have been warned.\n", mod->name);
3010 }
3011
3012 err = check_modinfo_livepatch(mod, info);
3013 if (err)
3014 return err;
3015
3016 /* Set up license info based on the info section */
3017 set_license(mod, get_modinfo(info, "license"));
3018
3019 return 0;
3020}
3021
3022static int find_module_sections(struct module *mod, struct load_info *info)
3023{
3024 mod->kp = section_objs(info, "__param",
3025 sizeof(*mod->kp), &mod->num_kp);
3026 mod->syms = section_objs(info, "__ksymtab",
3027 sizeof(*mod->syms), &mod->num_syms);
3028 mod->crcs = section_addr(info, "__kcrctab");
3029 mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
3030 sizeof(*mod->gpl_syms),
3031 &mod->num_gpl_syms);
3032 mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
3033 mod->gpl_future_syms = section_objs(info,
3034 "__ksymtab_gpl_future",
3035 sizeof(*mod->gpl_future_syms),
3036 &mod->num_gpl_future_syms);
3037 mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future");
3038
3039#ifdef CONFIG_UNUSED_SYMBOLS
3040 mod->unused_syms = section_objs(info, "__ksymtab_unused",
3041 sizeof(*mod->unused_syms),
3042 &mod->num_unused_syms);
3043 mod->unused_crcs = section_addr(info, "__kcrctab_unused");
3044 mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl",
3045 sizeof(*mod->unused_gpl_syms),
3046 &mod->num_unused_gpl_syms);
3047 mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl");
3048#endif
3049#ifdef CONFIG_CONSTRUCTORS
3050 mod->ctors = section_objs(info, ".ctors",
3051 sizeof(*mod->ctors), &mod->num_ctors);
3052 if (!mod->ctors)
3053 mod->ctors = section_objs(info, ".init_array",
3054 sizeof(*mod->ctors), &mod->num_ctors);
3055 else if (find_sec(info, ".init_array")) {
3056 /*
3057 * This shouldn't happen with same compiler and binutils
3058 * building all parts of the module.
3059 */
3060 pr_warn("%s: has both .ctors and .init_array.\n",
3061 mod->name);
3062 return -EINVAL;
3063 }
3064#endif
3065
3066#ifdef CONFIG_TRACEPOINTS
3067 mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
3068 sizeof(*mod->tracepoints_ptrs),
3069 &mod->num_tracepoints);
3070#endif
3071#ifdef HAVE_JUMP_LABEL
3072 mod->jump_entries = section_objs(info, "__jump_table",
3073 sizeof(*mod->jump_entries),
3074 &mod->num_jump_entries);
3075#endif
3076#ifdef CONFIG_EVENT_TRACING
3077 mod->trace_events = section_objs(info, "_ftrace_events",
3078 sizeof(*mod->trace_events),
3079 &mod->num_trace_events);
3080 mod->trace_enums = section_objs(info, "_ftrace_enum_map",
3081 sizeof(*mod->trace_enums),
3082 &mod->num_trace_enums);
3083#endif
3084#ifdef CONFIG_TRACING
3085 mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
3086 sizeof(*mod->trace_bprintk_fmt_start),
3087 &mod->num_trace_bprintk_fmt);
3088#endif
3089#ifdef CONFIG_FTRACE_MCOUNT_RECORD
3090 /* sechdrs[0].sh_size is always zero */
3091 mod->ftrace_callsites = section_objs(info, "__mcount_loc",
3092 sizeof(*mod->ftrace_callsites),
3093 &mod->num_ftrace_callsites);
3094#endif
3095
3096 mod->extable = section_objs(info, "__ex_table",
3097 sizeof(*mod->extable), &mod->num_exentries);
3098
3099 if (section_addr(info, "__obsparm"))
3100 pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
3101
3102 info->debug = section_objs(info, "__verbose",
3103 sizeof(*info->debug), &info->num_debug);
3104
3105 return 0;
3106}
3107
3108static int move_module(struct module *mod, struct load_info *info)
3109{
3110 int i;
3111 void *ptr;
3112
3113 /* Do the allocs. */
3114 ptr = module_alloc(mod->core_layout.size);
3115 /*
3116 * The pointer to this block is stored in the module structure
3117 * which is inside the block. Just mark it as not being a
3118 * leak.
3119 */
3120 kmemleak_not_leak(ptr);
3121 if (!ptr)
3122 return -ENOMEM;
3123
3124 memset(ptr, 0, mod->core_layout.size);
3125 mod->core_layout.base = ptr;
3126
3127 if (mod->init_layout.size) {
3128 ptr = module_alloc(mod->init_layout.size);
3129 /*
3130 * The pointer to this block is stored in the module structure
3131 * which is inside the block. This block doesn't need to be
3132 * scanned as it contains data and code that will be freed
3133 * after the module is initialized.
3134 */
3135 kmemleak_ignore(ptr);
3136 if (!ptr) {
3137 module_memfree(mod->core_layout.base);
3138 return -ENOMEM;
3139 }
3140 memset(ptr, 0, mod->init_layout.size);
3141 mod->init_layout.base = ptr;
3142 } else
3143 mod->init_layout.base = NULL;
3144
3145 /* Transfer each section which specifies SHF_ALLOC */
3146 pr_debug("final section addresses:\n");
3147 for (i = 0; i < info->hdr->e_shnum; i++) {
3148 void *dest;
3149 Elf_Shdr *shdr = &info->sechdrs[i];
3150
3151 if (!(shdr->sh_flags & SHF_ALLOC))
3152 continue;
3153
3154 if (shdr->sh_entsize & INIT_OFFSET_MASK)
3155 dest = mod->init_layout.base
3156 + (shdr->sh_entsize & ~INIT_OFFSET_MASK);
3157 else
3158 dest = mod->core_layout.base + shdr->sh_entsize;
3159
3160 if (shdr->sh_type != SHT_NOBITS)
3161 memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
3162 /* Update sh_addr to point to copy in image. */
3163 shdr->sh_addr = (unsigned long)dest;
3164 pr_debug("\t0x%lx %s\n",
3165 (long)shdr->sh_addr, info->secstrings + shdr->sh_name);
3166 }
3167
3168 return 0;
3169}
3170
3171static int check_module_license_and_versions(struct module *mod)
3172{
3173 int prev_taint = test_taint(TAINT_PROPRIETARY_MODULE);
3174
3175 /*
3176 * ndiswrapper is under GPL by itself, but loads proprietary modules.
3177 * Don't use add_taint_module(), as it would prevent ndiswrapper from
3178 * using GPL-only symbols it needs.
3179 */
3180 if (strcmp(mod->name, "ndiswrapper") == 0)
3181 add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
3182
3183 /* driverloader was caught wrongly pretending to be under GPL */
3184 if (strcmp(mod->name, "driverloader") == 0)
3185 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3186 LOCKDEP_NOW_UNRELIABLE);
3187
3188 /* lve claims to be GPL but upstream won't provide source */
3189 if (strcmp(mod->name, "lve") == 0)
3190 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3191 LOCKDEP_NOW_UNRELIABLE);
3192
3193 if (!prev_taint && test_taint(TAINT_PROPRIETARY_MODULE))
3194 pr_warn("%s: module license taints kernel.\n", mod->name);
3195
3196#ifdef CONFIG_MODVERSIONS
3197 if ((mod->num_syms && !mod->crcs)
3198 || (mod->num_gpl_syms && !mod->gpl_crcs)
3199 || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
3200#ifdef CONFIG_UNUSED_SYMBOLS
3201 || (mod->num_unused_syms && !mod->unused_crcs)
3202 || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
3203#endif
3204 ) {
3205 return try_to_force_load(mod,
3206 "no versions for exported symbols");
3207 }
3208#endif
3209 return 0;
3210}
3211
3212static void flush_module_icache(const struct module *mod)
3213{
3214 mm_segment_t old_fs;
3215
3216 /* flush the icache in correct context */
3217 old_fs = get_fs();
3218 set_fs(KERNEL_DS);
3219
3220 /*
3221 * Flush the instruction cache, since we've played with text.
3222 * Do it before processing of module parameters, so the module
3223 * can provide parameter accessor functions of its own.
3224 */
3225 if (mod->init_layout.base)
3226 flush_icache_range((unsigned long)mod->init_layout.base,
3227 (unsigned long)mod->init_layout.base
3228 + mod->init_layout.size);
3229 flush_icache_range((unsigned long)mod->core_layout.base,
3230 (unsigned long)mod->core_layout.base + mod->core_layout.size);
3231
3232 set_fs(old_fs);
3233}
3234
3235int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
3236 Elf_Shdr *sechdrs,
3237 char *secstrings,
3238 struct module *mod)
3239{
3240 return 0;
3241}
3242
3243/* module_blacklist is a comma-separated list of module names */
3244static char *module_blacklist;
3245static bool blacklisted(char *module_name)
3246{
3247 const char *p;
3248 size_t len;
3249
3250 if (!module_blacklist)
3251 return false;
3252
3253 for (p = module_blacklist; *p; p += len) {
3254 len = strcspn(p, ",");
3255 if (strlen(module_name) == len && !memcmp(module_name, p, len))
3256 return true;
3257 if (p[len] == ',')
3258 len++;
3259 }
3260 return false;
3261}
3262core_param(module_blacklist, module_blacklist, charp, 0400);
3263
3264static struct module *layout_and_allocate(struct load_info *info, int flags)
3265{
3266 /* Module within temporary copy. */
3267 struct module *mod;
3268 unsigned int ndx;
3269 int err;
3270
3271 mod = setup_load_info(info, flags);
3272 if (IS_ERR(mod))
3273 return mod;
3274
3275 if (blacklisted(mod->name))
3276 return ERR_PTR(-EPERM);
3277
3278 err = check_modinfo(mod, info, flags);
3279 if (err)
3280 return ERR_PTR(err);
3281
3282 /* Allow arches to frob section contents and sizes. */
3283 err = module_frob_arch_sections(info->hdr, info->sechdrs,
3284 info->secstrings, mod);
3285 if (err < 0)
3286 return ERR_PTR(err);
3287
3288 /* We will do a special allocation for per-cpu sections later. */
3289 info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC;
3290
3291 /*
3292 * Mark ro_after_init section with SHF_RO_AFTER_INIT so that
3293 * layout_sections() can put it in the right place.
3294 * Note: ro_after_init sections also have SHF_{WRITE,ALLOC} set.
3295 */
3296 ndx = find_sec(info, ".data..ro_after_init");
3297 if (ndx)
3298 info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT;
3299
3300 /* Determine total sizes, and put offsets in sh_entsize. For now
3301 this is done generically; there doesn't appear to be any
3302 special cases for the architectures. */
3303 layout_sections(mod, info);
3304 layout_symtab(mod, info);
3305
3306 /* Allocate and move to the final place */
3307 err = move_module(mod, info);
3308 if (err)
3309 return ERR_PTR(err);
3310
3311 /* Module has been copied to its final place now: return it. */
3312 mod = (void *)info->sechdrs[info->index.mod].sh_addr;
3313 kmemleak_load_module(mod, info);
3314 return mod;
3315}
3316
3317/* mod is no longer valid after this! */
3318static void module_deallocate(struct module *mod, struct load_info *info)
3319{
3320 percpu_modfree(mod);
3321 module_arch_freeing_init(mod);
3322 module_memfree(mod->init_layout.base);
3323 module_memfree(mod->core_layout.base);
3324}
3325
3326int __weak module_finalize(const Elf_Ehdr *hdr,
3327 const Elf_Shdr *sechdrs,
3328 struct module *me)
3329{
3330 return 0;
3331}
3332
3333static int post_relocation(struct module *mod, const struct load_info *info)
3334{
3335 /* Sort exception table now relocations are done. */
3336 sort_extable(mod->extable, mod->extable + mod->num_exentries);
3337
3338 /* Copy relocated percpu area over. */
3339 percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
3340 info->sechdrs[info->index.pcpu].sh_size);
3341
3342 /* Setup kallsyms-specific fields. */
3343 add_kallsyms(mod, info);
3344
3345 /* Arch-specific module finalizing. */
3346 return module_finalize(info->hdr, info->sechdrs, mod);
3347}
3348
3349/* Is this module of this name done loading? No locks held. */
3350static bool finished_loading(const char *name)
3351{
3352 struct module *mod;
3353 bool ret;
3354
3355 /*
3356 * The module_mutex should not be a heavily contended lock;
3357 * if we get the occasional sleep here, we'll go an extra iteration
3358 * in the wait_event_interruptible(), which is harmless.
3359 */
3360 sched_annotate_sleep();
3361 mutex_lock(&module_mutex);
3362 mod = find_module_all(name, strlen(name), true);
3363 ret = !mod || mod->state == MODULE_STATE_LIVE
3364 || mod->state == MODULE_STATE_GOING;
3365 mutex_unlock(&module_mutex);
3366
3367 return ret;
3368}
3369
3370/* Call module constructors. */
3371static void do_mod_ctors(struct module *mod)
3372{
3373#ifdef CONFIG_CONSTRUCTORS
3374 unsigned long i;
3375
3376 for (i = 0; i < mod->num_ctors; i++)
3377 mod->ctors[i]();
3378#endif
3379}
3380
3381/* For freeing module_init on success, in case kallsyms traversing */
3382struct mod_initfree {
3383 struct rcu_head rcu;
3384 void *module_init;
3385};
3386
3387static void do_free_init(struct rcu_head *head)
3388{
3389 struct mod_initfree *m = container_of(head, struct mod_initfree, rcu);
3390 module_memfree(m->module_init);
3391 kfree(m);
3392}
3393
3394/*
3395 * This is where the real work happens.
3396 *
3397 * Keep it uninlined to provide a reliable breakpoint target, e.g. for the gdb
3398 * helper command 'lx-symbols'.
3399 */
3400static noinline int do_init_module(struct module *mod)
3401{
3402 int ret = 0;
3403 struct mod_initfree *freeinit;
3404
3405 freeinit = kmalloc(sizeof(*freeinit), GFP_KERNEL);
3406 if (!freeinit) {
3407 ret = -ENOMEM;
3408 goto fail;
3409 }
3410 freeinit->module_init = mod->init_layout.base;
3411
3412 /*
3413 * We want to find out whether @mod uses async during init. Clear
3414 * PF_USED_ASYNC. async_schedule*() will set it.
3415 */
3416 current->flags &= ~PF_USED_ASYNC;
3417
3418 do_mod_ctors(mod);
3419 /* Start the module */
3420 if (mod->init != NULL)
3421 ret = do_one_initcall(mod->init);
3422 if (ret < 0) {
3423 goto fail_free_freeinit;
3424 }
3425 if (ret > 0) {
3426 pr_warn("%s: '%s'->init suspiciously returned %d, it should "
3427 "follow 0/-E convention\n"
3428 "%s: loading module anyway...\n",
3429 __func__, mod->name, ret, __func__);
3430 dump_stack();
3431 }
3432
3433 /* Now it's a first class citizen! */
3434 mod->state = MODULE_STATE_LIVE;
3435 blocking_notifier_call_chain(&module_notify_list,
3436 MODULE_STATE_LIVE, mod);
3437
3438 /*
3439 * We need to finish all async code before the module init sequence
3440 * is done. This has potential to deadlock. For example, a newly
3441 * detected block device can trigger request_module() of the
3442 * default iosched from async probing task. Once userland helper
3443 * reaches here, async_synchronize_full() will wait on the async
3444 * task waiting on request_module() and deadlock.
3445 *
3446 * This deadlock is avoided by perfomring async_synchronize_full()
3447 * iff module init queued any async jobs. This isn't a full
3448 * solution as it will deadlock the same if module loading from
3449 * async jobs nests more than once; however, due to the various
3450 * constraints, this hack seems to be the best option for now.
3451 * Please refer to the following thread for details.
3452 *
3453 * http://thread.gmane.org/gmane.linux.kernel/1420814
3454 */
3455 if (!mod->async_probe_requested && (current->flags & PF_USED_ASYNC))
3456 async_synchronize_full();
3457
3458 mutex_lock(&module_mutex);
3459 /* Drop initial reference. */
3460 module_put(mod);
3461 trim_init_extable(mod);
3462#ifdef CONFIG_KALLSYMS
3463 /* Switch to core kallsyms now init is done: kallsyms may be walking! */
3464 rcu_assign_pointer(mod->kallsyms, &mod->core_kallsyms);
3465#endif
3466 module_enable_ro(mod, true);
3467 mod_tree_remove_init(mod);
3468 disable_ro_nx(&mod->init_layout);
3469 module_arch_freeing_init(mod);
3470 mod->init_layout.base = NULL;
3471 mod->init_layout.size = 0;
3472 mod->init_layout.ro_size = 0;
3473 mod->init_layout.ro_after_init_size = 0;
3474 mod->init_layout.text_size = 0;
3475 /*
3476 * We want to free module_init, but be aware that kallsyms may be
3477 * walking this with preempt disabled. In all the failure paths, we
3478 * call synchronize_sched(), but we don't want to slow down the success
3479 * path, so use actual RCU here.
3480 */
3481 call_rcu_sched(&freeinit->rcu, do_free_init);
3482 mutex_unlock(&module_mutex);
3483 wake_up_all(&module_wq);
3484
3485 return 0;
3486
3487fail_free_freeinit:
3488 kfree(freeinit);
3489fail:
3490 /* Try to protect us from buggy refcounters. */
3491 mod->state = MODULE_STATE_GOING;
3492 synchronize_sched();
3493 module_put(mod);
3494 blocking_notifier_call_chain(&module_notify_list,
3495 MODULE_STATE_GOING, mod);
3496 klp_module_going(mod);
3497 ftrace_release_mod(mod);
3498 free_module(mod);
3499 wake_up_all(&module_wq);
3500 return ret;
3501}
3502
3503static int may_init_module(void)
3504{
3505 if (!capable(CAP_SYS_MODULE) || modules_disabled)
3506 return -EPERM;
3507
3508 return 0;
3509}
3510
3511/*
3512 * We try to place it in the list now to make sure it's unique before
3513 * we dedicate too many resources. In particular, temporary percpu
3514 * memory exhaustion.
3515 */
3516static int add_unformed_module(struct module *mod)
3517{
3518 int err;
3519 struct module *old;
3520
3521 mod->state = MODULE_STATE_UNFORMED;
3522
3523again:
3524 mutex_lock(&module_mutex);
3525 old = find_module_all(mod->name, strlen(mod->name), true);
3526 if (old != NULL) {
3527 if (old->state == MODULE_STATE_COMING
3528 || old->state == MODULE_STATE_UNFORMED) {
3529 /* Wait in case it fails to load. */
3530 mutex_unlock(&module_mutex);
3531 err = wait_event_interruptible(module_wq,
3532 finished_loading(mod->name));
3533 if (err)
3534 goto out_unlocked;
3535 goto again;
3536 }
3537 err = -EEXIST;
3538 goto out;
3539 }
3540 mod_update_bounds(mod);
3541 list_add_rcu(&mod->list, &modules);
3542 mod_tree_insert(mod);
3543 err = 0;
3544
3545out:
3546 mutex_unlock(&module_mutex);
3547out_unlocked:
3548 return err;
3549}
3550
3551static int complete_formation(struct module *mod, struct load_info *info)
3552{
3553 int err;
3554
3555 mutex_lock(&module_mutex);
3556
3557 /* Find duplicate symbols (must be called under lock). */
3558 err = verify_export_symbols(mod);
3559 if (err < 0)
3560 goto out;
3561
3562 /* This relies on module_mutex for list integrity. */
3563 module_bug_finalize(info->hdr, info->sechdrs, mod);
3564
3565 module_enable_ro(mod, false);
3566 module_enable_nx(mod);
3567
3568 /* Mark state as coming so strong_try_module_get() ignores us,
3569 * but kallsyms etc. can see us. */
3570 mod->state = MODULE_STATE_COMING;
3571 mutex_unlock(&module_mutex);
3572
3573 return 0;
3574
3575out:
3576 mutex_unlock(&module_mutex);
3577 return err;
3578}
3579
3580static int prepare_coming_module(struct module *mod)
3581{
3582 int err;
3583
3584 ftrace_module_enable(mod);
3585 err = klp_module_coming(mod);
3586 if (err)
3587 return err;
3588
3589 blocking_notifier_call_chain(&module_notify_list,
3590 MODULE_STATE_COMING, mod);
3591 return 0;
3592}
3593
3594static int unknown_module_param_cb(char *param, char *val, const char *modname,
3595 void *arg)
3596{
3597 struct module *mod = arg;
3598 int ret;
3599
3600 if (strcmp(param, "async_probe") == 0) {
3601 mod->async_probe_requested = true;
3602 return 0;
3603 }
3604
3605 /* Check for magic 'dyndbg' arg */
3606 ret = ddebug_dyndbg_module_param_cb(param, val, modname);
3607 if (ret != 0)
3608 pr_warn("%s: unknown parameter '%s' ignored\n", modname, param);
3609 return 0;
3610}
3611
3612/* Allocate and load the module: note that size of section 0 is always
3613 zero, and we rely on this for optional sections. */
3614static int load_module(struct load_info *info, const char __user *uargs,
3615 int flags)
3616{
3617 struct module *mod;
3618 long err;
3619 char *after_dashes;
3620
3621 err = module_sig_check(info, flags);
3622 if (err)
3623 goto free_copy;
3624
3625 err = elf_header_check(info);
3626 if (err)
3627 goto free_copy;
3628
3629 /* Figure out module layout, and allocate all the memory. */
3630 mod = layout_and_allocate(info, flags);
3631 if (IS_ERR(mod)) {
3632 err = PTR_ERR(mod);
3633 goto free_copy;
3634 }
3635
3636 audit_log_kern_module(mod->name);
3637
3638 /* Reserve our place in the list. */
3639 err = add_unformed_module(mod);
3640 if (err)
3641 goto free_module;
3642
3643#ifdef CONFIG_MODULE_SIG
3644 mod->sig_ok = info->sig_ok;
3645 if (!mod->sig_ok) {
3646 pr_notice_once("%s: module verification failed: signature "
3647 "and/or required key missing - tainting "
3648 "kernel\n", mod->name);
3649 add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK);
3650 }
3651#endif
3652
3653 /* To avoid stressing percpu allocator, do this once we're unique. */
3654 err = percpu_modalloc(mod, info);
3655 if (err)
3656 goto unlink_mod;
3657
3658 /* Now module is in final location, initialize linked lists, etc. */
3659 err = module_unload_init(mod);
3660 if (err)
3661 goto unlink_mod;
3662
3663 init_param_lock(mod);
3664
3665 /* Now we've got everything in the final locations, we can
3666 * find optional sections. */
3667 err = find_module_sections(mod, info);
3668 if (err)
3669 goto free_unload;
3670
3671 err = check_module_license_and_versions(mod);
3672 if (err)
3673 goto free_unload;
3674
3675 /* Set up MODINFO_ATTR fields */
3676 setup_modinfo(mod, info);
3677
3678 /* Fix up syms, so that st_value is a pointer to location. */
3679 err = simplify_symbols(mod, info);
3680 if (err < 0)
3681 goto free_modinfo;
3682
3683 err = apply_relocations(mod, info);
3684 if (err < 0)
3685 goto free_modinfo;
3686
3687 err = post_relocation(mod, info);
3688 if (err < 0)
3689 goto free_modinfo;
3690
3691 flush_module_icache(mod);
3692
3693 /* Now copy in args */
3694 mod->args = strndup_user(uargs, ~0UL >> 1);
3695 if (IS_ERR(mod->args)) {
3696 err = PTR_ERR(mod->args);
3697 goto free_arch_cleanup;
3698 }
3699
3700 dynamic_debug_setup(info->debug, info->num_debug);
3701
3702 /* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
3703 ftrace_module_init(mod);
3704
3705 /* Finally it's fully formed, ready to start executing. */
3706 err = complete_formation(mod, info);
3707 if (err)
3708 goto ddebug_cleanup;
3709
3710 err = prepare_coming_module(mod);
3711 if (err)
3712 goto bug_cleanup;
3713
3714 /* Module is ready to execute: parsing args may do that. */
3715 after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
3716 -32768, 32767, mod,
3717 unknown_module_param_cb);
3718 if (IS_ERR(after_dashes)) {
3719 err = PTR_ERR(after_dashes);
3720 goto coming_cleanup;
3721 } else if (after_dashes) {
3722 pr_warn("%s: parameters '%s' after `--' ignored\n",
3723 mod->name, after_dashes);
3724 }
3725
3726 /* Link in to sysfs. */
3727 err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
3728 if (err < 0)
3729 goto coming_cleanup;
3730
3731 if (is_livepatch_module(mod)) {
3732 err = copy_module_elf(mod, info);
3733 if (err < 0)
3734 goto sysfs_cleanup;
3735 }
3736
3737 /* Get rid of temporary copy. */
3738 free_copy(info);
3739
3740 /* Done! */
3741 trace_module_load(mod);
3742
3743 return do_init_module(mod);
3744
3745 sysfs_cleanup:
3746 mod_sysfs_teardown(mod);
3747 coming_cleanup:
3748 mod->state = MODULE_STATE_GOING;
3749 destroy_params(mod->kp, mod->num_kp);
3750 blocking_notifier_call_chain(&module_notify_list,
3751 MODULE_STATE_GOING, mod);
3752 klp_module_going(mod);
3753 bug_cleanup:
3754 /* module_bug_cleanup needs module_mutex protection */
3755 mutex_lock(&module_mutex);
3756 module_bug_cleanup(mod);
3757 mutex_unlock(&module_mutex);
3758
3759 /* we can't deallocate the module until we clear memory protection */
3760 module_disable_ro(mod);
3761 module_disable_nx(mod);
3762
3763 ddebug_cleanup:
3764 dynamic_debug_remove(info->debug);
3765 synchronize_sched();
3766 kfree(mod->args);
3767 free_arch_cleanup:
3768 module_arch_cleanup(mod);
3769 free_modinfo:
3770 free_modinfo(mod);
3771 free_unload:
3772 module_unload_free(mod);
3773 unlink_mod:
3774 mutex_lock(&module_mutex);
3775 /* Unlink carefully: kallsyms could be walking list. */
3776 list_del_rcu(&mod->list);
3777 mod_tree_remove(mod);
3778 wake_up_all(&module_wq);
3779 /* Wait for RCU-sched synchronizing before releasing mod->list. */
3780 synchronize_sched();
3781 mutex_unlock(&module_mutex);
3782 free_module:
3783 /*
3784 * Ftrace needs to clean up what it initialized.
3785 * This does nothing if ftrace_module_init() wasn't called,
3786 * but it must be called outside of module_mutex.
3787 */
3788 ftrace_release_mod(mod);
3789 /* Free lock-classes; relies on the preceding sync_rcu() */
3790 lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
3791
3792 module_deallocate(mod, info);
3793 free_copy:
3794 free_copy(info);
3795 return err;
3796}
3797
3798SYSCALL_DEFINE3(init_module, void __user *, umod,
3799 unsigned long, len, const char __user *, uargs)
3800{
3801 int err;
3802 struct load_info info = { };
3803
3804 err = may_init_module();
3805 if (err)
3806 return err;
3807
3808 pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
3809 umod, len, uargs);
3810
3811 err = copy_module_from_user(umod, len, &info);
3812 if (err)
3813 return err;
3814
3815 return load_module(&info, uargs, 0);
3816}
3817
3818SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
3819{
3820 struct load_info info = { };
3821 loff_t size;
3822 void *hdr;
3823 int err;
3824
3825 err = may_init_module();
3826 if (err)
3827 return err;
3828
3829 pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags);
3830
3831 if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS
3832 |MODULE_INIT_IGNORE_VERMAGIC))
3833 return -EINVAL;
3834
3835 err = kernel_read_file_from_fd(fd, &hdr, &size, INT_MAX,
3836 READING_MODULE);
3837 if (err)
3838 return err;
3839 info.hdr = hdr;
3840 info.len = size;
3841
3842 return load_module(&info, uargs, flags);
3843}
3844
3845static inline int within(unsigned long addr, void *start, unsigned long size)
3846{
3847 return ((void *)addr >= start && (void *)addr < start + size);
3848}
3849
3850#ifdef CONFIG_KALLSYMS
3851/*
3852 * This ignores the intensely annoying "mapping symbols" found
3853 * in ARM ELF files: $a, $t and $d.
3854 */
3855static inline int is_arm_mapping_symbol(const char *str)
3856{
3857 if (str[0] == '.' && str[1] == 'L')
3858 return true;
3859 return str[0] == '$' && strchr("axtd", str[1])
3860 && (str[2] == '\0' || str[2] == '.');
3861}
3862
3863static const char *symname(struct mod_kallsyms *kallsyms, unsigned int symnum)
3864{
3865 return kallsyms->strtab + kallsyms->symtab[symnum].st_name;
3866}
3867
3868static const char *get_ksymbol(struct module *mod,
3869 unsigned long addr,
3870 unsigned long *size,
3871 unsigned long *offset)
3872{
3873 unsigned int i, best = 0;
3874 unsigned long nextval;
3875 struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
3876
3877 /* At worse, next value is at end of module */
3878 if (within_module_init(addr, mod))
3879 nextval = (unsigned long)mod->init_layout.base+mod->init_layout.text_size;
3880 else
3881 nextval = (unsigned long)mod->core_layout.base+mod->core_layout.text_size;
3882
3883 /* Scan for closest preceding symbol, and next symbol. (ELF
3884 starts real symbols at 1). */
3885 for (i = 1; i < kallsyms->num_symtab; i++) {
3886 if (kallsyms->symtab[i].st_shndx == SHN_UNDEF)
3887 continue;
3888
3889 /* We ignore unnamed symbols: they're uninformative
3890 * and inserted at a whim. */
3891 if (*symname(kallsyms, i) == '\0'
3892 || is_arm_mapping_symbol(symname(kallsyms, i)))
3893 continue;
3894
3895 if (kallsyms->symtab[i].st_value <= addr
3896 && kallsyms->symtab[i].st_value > kallsyms->symtab[best].st_value)
3897 best = i;
3898 if (kallsyms->symtab[i].st_value > addr
3899 && kallsyms->symtab[i].st_value < nextval)
3900 nextval = kallsyms->symtab[i].st_value;
3901 }
3902
3903 if (!best)
3904 return NULL;
3905
3906 if (size)
3907 *size = nextval - kallsyms->symtab[best].st_value;
3908 if (offset)
3909 *offset = addr - kallsyms->symtab[best].st_value;
3910 return symname(kallsyms, best);
3911}
3912
3913/* For kallsyms to ask for address resolution. NULL means not found. Careful
3914 * not to lock to avoid deadlock on oopses, simply disable preemption. */
3915const char *module_address_lookup(unsigned long addr,
3916 unsigned long *size,
3917 unsigned long *offset,
3918 char **modname,
3919 char *namebuf)
3920{
3921 const char *ret = NULL;
3922 struct module *mod;
3923
3924 preempt_disable();
3925 mod = __module_address(addr);
3926 if (mod) {
3927 if (modname)
3928 *modname = mod->name;
3929 ret = get_ksymbol(mod, addr, size, offset);
3930 }
3931 /* Make a copy in here where it's safe */
3932 if (ret) {
3933 strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
3934 ret = namebuf;
3935 }
3936 preempt_enable();
3937
3938 return ret;
3939}
3940
3941int lookup_module_symbol_name(unsigned long addr, char *symname)
3942{
3943 struct module *mod;
3944
3945 preempt_disable();
3946 list_for_each_entry_rcu(mod, &modules, list) {
3947 if (mod->state == MODULE_STATE_UNFORMED)
3948 continue;
3949 if (within_module(addr, mod)) {
3950 const char *sym;
3951
3952 sym = get_ksymbol(mod, addr, NULL, NULL);
3953 if (!sym)
3954 goto out;
3955 strlcpy(symname, sym, KSYM_NAME_LEN);
3956 preempt_enable();
3957 return 0;
3958 }
3959 }
3960out:
3961 preempt_enable();
3962 return -ERANGE;
3963}
3964
3965int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
3966 unsigned long *offset, char *modname, char *name)
3967{
3968 struct module *mod;
3969
3970 preempt_disable();
3971 list_for_each_entry_rcu(mod, &modules, list) {
3972 if (mod->state == MODULE_STATE_UNFORMED)
3973 continue;
3974 if (within_module(addr, mod)) {
3975 const char *sym;
3976
3977 sym = get_ksymbol(mod, addr, size, offset);
3978 if (!sym)
3979 goto out;
3980 if (modname)
3981 strlcpy(modname, mod->name, MODULE_NAME_LEN);
3982 if (name)
3983 strlcpy(name, sym, KSYM_NAME_LEN);
3984 preempt_enable();
3985 return 0;
3986 }
3987 }
3988out:
3989 preempt_enable();
3990 return -ERANGE;
3991}
3992
3993int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
3994 char *name, char *module_name, int *exported)
3995{
3996 struct module *mod;
3997
3998 preempt_disable();
3999 list_for_each_entry_rcu(mod, &modules, list) {
4000 struct mod_kallsyms *kallsyms;
4001
4002 if (mod->state == MODULE_STATE_UNFORMED)
4003 continue;
4004 kallsyms = rcu_dereference_sched(mod->kallsyms);
4005 if (symnum < kallsyms->num_symtab) {
4006 *value = kallsyms->symtab[symnum].st_value;
4007 *type = kallsyms->symtab[symnum].st_info;
4008 strlcpy(name, symname(kallsyms, symnum), KSYM_NAME_LEN);
4009 strlcpy(module_name, mod->name, MODULE_NAME_LEN);
4010 *exported = is_exported(name, *value, mod);
4011 preempt_enable();
4012 return 0;
4013 }
4014 symnum -= kallsyms->num_symtab;
4015 }
4016 preempt_enable();
4017 return -ERANGE;
4018}
4019
4020static unsigned long mod_find_symname(struct module *mod, const char *name)
4021{
4022 unsigned int i;
4023 struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
4024
4025 for (i = 0; i < kallsyms->num_symtab; i++)
4026 if (strcmp(name, symname(kallsyms, i)) == 0 &&
4027 kallsyms->symtab[i].st_info != 'U')
4028 return kallsyms->symtab[i].st_value;
4029 return 0;
4030}
4031
4032/* Look for this name: can be of form module:name. */
4033unsigned long module_kallsyms_lookup_name(const char *name)
4034{
4035 struct module *mod;
4036 char *colon;
4037 unsigned long ret = 0;
4038
4039 /* Don't lock: we're in enough trouble already. */
4040 preempt_disable();
4041 if ((colon = strnchr(name, MODULE_NAME_LEN, ':')) != NULL) {
4042 if ((mod = find_module_all(name, colon - name, false)) != NULL)
4043 ret = mod_find_symname(mod, colon+1);
4044 } else {
4045 list_for_each_entry_rcu(mod, &modules, list) {
4046 if (mod->state == MODULE_STATE_UNFORMED)
4047 continue;
4048 if ((ret = mod_find_symname(mod, name)) != 0)
4049 break;
4050 }
4051 }
4052 preempt_enable();
4053 return ret;
4054}
4055
4056int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
4057 struct module *, unsigned long),
4058 void *data)
4059{
4060 struct module *mod;
4061 unsigned int i;
4062 int ret;
4063
4064 module_assert_mutex();
4065
4066 list_for_each_entry(mod, &modules, list) {
4067 /* We hold module_mutex: no need for rcu_dereference_sched */
4068 struct mod_kallsyms *kallsyms = mod->kallsyms;
4069
4070 if (mod->state == MODULE_STATE_UNFORMED)
4071 continue;
4072 for (i = 0; i < kallsyms->num_symtab; i++) {
4073 ret = fn(data, symname(kallsyms, i),
4074 mod, kallsyms->symtab[i].st_value);
4075 if (ret != 0)
4076 return ret;
4077 }
4078 }
4079 return 0;
4080}
4081#endif /* CONFIG_KALLSYMS */
4082
4083/* Maximum number of characters written by module_flags() */
4084#define MODULE_FLAGS_BUF_SIZE (TAINT_FLAGS_COUNT + 4)
4085
4086/* Keep in sync with MODULE_FLAGS_BUF_SIZE !!! */
4087static char *module_flags(struct module *mod, char *buf)
4088{
4089 int bx = 0;
4090
4091 BUG_ON(mod->state == MODULE_STATE_UNFORMED);
4092 if (mod->taints ||
4093 mod->state == MODULE_STATE_GOING ||
4094 mod->state == MODULE_STATE_COMING) {
4095 buf[bx++] = '(';
4096 bx += module_flags_taint(mod, buf + bx);
4097 /* Show a - for module-is-being-unloaded */
4098 if (mod->state == MODULE_STATE_GOING)
4099 buf[bx++] = '-';
4100 /* Show a + for module-is-being-loaded */
4101 if (mod->state == MODULE_STATE_COMING)
4102 buf[bx++] = '+';
4103 buf[bx++] = ')';
4104 }
4105 buf[bx] = '\0';
4106
4107 return buf;
4108}
4109
4110#ifdef CONFIG_PROC_FS
4111/* Called by the /proc file system to return a list of modules. */
4112static void *m_start(struct seq_file *m, loff_t *pos)
4113{
4114 mutex_lock(&module_mutex);
4115 return seq_list_start(&modules, *pos);
4116}
4117
4118static void *m_next(struct seq_file *m, void *p, loff_t *pos)
4119{
4120 return seq_list_next(p, &modules, pos);
4121}
4122
4123static void m_stop(struct seq_file *m, void *p)
4124{
4125 mutex_unlock(&module_mutex);
4126}
4127
4128static int m_show(struct seq_file *m, void *p)
4129{
4130 struct module *mod = list_entry(p, struct module, list);
4131 char buf[MODULE_FLAGS_BUF_SIZE];
4132
4133 /* We always ignore unformed modules. */
4134 if (mod->state == MODULE_STATE_UNFORMED)
4135 return 0;
4136
4137 seq_printf(m, "%s %u",
4138 mod->name, mod->init_layout.size + mod->core_layout.size);
4139 print_unload_info(m, mod);
4140
4141 /* Informative for users. */
4142 seq_printf(m, " %s",
4143 mod->state == MODULE_STATE_GOING ? "Unloading" :
4144 mod->state == MODULE_STATE_COMING ? "Loading" :
4145 "Live");
4146 /* Used by oprofile and other similar tools. */
4147 seq_printf(m, " 0x%pK", mod->core_layout.base);
4148
4149 /* Taints info */
4150 if (mod->taints)
4151 seq_printf(m, " %s", module_flags(mod, buf));
4152
4153 seq_puts(m, "\n");
4154 return 0;
4155}
4156
4157/* Format: modulename size refcount deps address
4158
4159 Where refcount is a number or -, and deps is a comma-separated list
4160 of depends or -.
4161*/
4162static const struct seq_operations modules_op = {
4163 .start = m_start,
4164 .next = m_next,
4165 .stop = m_stop,
4166 .show = m_show
4167};
4168
4169static int modules_open(struct inode *inode, struct file *file)
4170{
4171 return seq_open(file, &modules_op);
4172}
4173
4174static const struct file_operations proc_modules_operations = {
4175 .open = modules_open,
4176 .read = seq_read,
4177 .llseek = seq_lseek,
4178 .release = seq_release,
4179};
4180
4181static int __init proc_modules_init(void)
4182{
4183 proc_create("modules", 0, NULL, &proc_modules_operations);
4184 return 0;
4185}
4186module_init(proc_modules_init);
4187#endif
4188
4189/* Given an address, look for it in the module exception tables. */
4190const struct exception_table_entry *search_module_extables(unsigned long addr)
4191{
4192 const struct exception_table_entry *e = NULL;
4193 struct module *mod;
4194
4195 preempt_disable();
4196 mod = __module_address(addr);
4197 if (!mod)
4198 goto out;
4199
4200 if (!mod->num_exentries)
4201 goto out;
4202
4203 e = search_extable(mod->extable,
4204 mod->extable + mod->num_exentries - 1,
4205 addr);
4206out:
4207 preempt_enable();
4208
4209 /*
4210 * Now, if we found one, we are running inside it now, hence
4211 * we cannot unload the module, hence no refcnt needed.
4212 */
4213 return e;
4214}
4215
4216/*
4217 * is_module_address - is this address inside a module?
4218 * @addr: the address to check.
4219 *
4220 * See is_module_text_address() if you simply want to see if the address
4221 * is code (not data).
4222 */
4223bool is_module_address(unsigned long addr)
4224{
4225 bool ret;
4226
4227 preempt_disable();
4228 ret = __module_address(addr) != NULL;
4229 preempt_enable();
4230
4231 return ret;
4232}
4233
4234/*
4235 * __module_address - get the module which contains an address.
4236 * @addr: the address.
4237 *
4238 * Must be called with preempt disabled or module mutex held so that
4239 * module doesn't get freed during this.
4240 */
4241struct module *__module_address(unsigned long addr)
4242{
4243 struct module *mod;
4244
4245 if (addr < module_addr_min || addr > module_addr_max)
4246 return NULL;
4247
4248 module_assert_mutex_or_preempt();
4249
4250 mod = mod_find(addr);
4251 if (mod) {
4252 BUG_ON(!within_module(addr, mod));
4253 if (mod->state == MODULE_STATE_UNFORMED)
4254 mod = NULL;
4255 }
4256 return mod;
4257}
4258EXPORT_SYMBOL_GPL(__module_address);
4259
4260/*
4261 * is_module_text_address - is this address inside module code?
4262 * @addr: the address to check.
4263 *
4264 * See is_module_address() if you simply want to see if the address is
4265 * anywhere in a module. See kernel_text_address() for testing if an
4266 * address corresponds to kernel or module code.
4267 */
4268bool is_module_text_address(unsigned long addr)
4269{
4270 bool ret;
4271
4272 preempt_disable();
4273 ret = __module_text_address(addr) != NULL;
4274 preempt_enable();
4275
4276 return ret;
4277}
4278
4279/*
4280 * __module_text_address - get the module whose code contains an address.
4281 * @addr: the address.
4282 *
4283 * Must be called with preempt disabled or module mutex held so that
4284 * module doesn't get freed during this.
4285 */
4286struct module *__module_text_address(unsigned long addr)
4287{
4288 struct module *mod = __module_address(addr);
4289 if (mod) {
4290 /* Make sure it's within the text section. */
4291 if (!within(addr, mod->init_layout.base, mod->init_layout.text_size)
4292 && !within(addr, mod->core_layout.base, mod->core_layout.text_size))
4293 mod = NULL;
4294 }
4295 return mod;
4296}
4297EXPORT_SYMBOL_GPL(__module_text_address);
4298
4299/* Don't grab lock, we're oopsing. */
4300void print_modules(void)
4301{
4302 struct module *mod;
4303 char buf[MODULE_FLAGS_BUF_SIZE];
4304
4305 printk(KERN_DEFAULT "Modules linked in:");
4306 /* Most callers should already have preempt disabled, but make sure */
4307 preempt_disable();
4308 list_for_each_entry_rcu(mod, &modules, list) {
4309 if (mod->state == MODULE_STATE_UNFORMED)
4310 continue;
4311 pr_cont(" %s%s", mod->name, module_flags(mod, buf));
4312 }
4313 preempt_enable();
4314 if (last_unloaded_module[0])
4315 pr_cont(" [last unloaded: %s]", last_unloaded_module);
4316 pr_cont("\n");
4317}
4318
4319#ifdef CONFIG_MODVERSIONS
4320/* Generate the signature for all relevant module structures here.
4321 * If these change, we don't want to try to parse the module. */
4322void module_layout(struct module *mod,
4323 struct modversion_info *ver,
4324 struct kernel_param *kp,
4325 struct kernel_symbol *ks,
4326 struct tracepoint * const *tp)
4327{
4328}
4329EXPORT_SYMBOL(module_layout);
4330#endif