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1/*
2 Copyright (C) 2002 Richard Henderson
3 Copyright (C) 2001 Rusty Russell, 2002, 2010 Rusty Russell IBM.
4
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 2 of the License, or
8 (at your option) any later version.
9
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
14
15 You should have received a copy of the GNU General Public License
16 along with this program; if not, write to the Free Software
17 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18*/
19#include <linux/export.h>
20#include <linux/moduleloader.h>
21#include <linux/trace_events.h>
22#include <linux/init.h>
23#include <linux/kallsyms.h>
24#include <linux/file.h>
25#include <linux/fs.h>
26#include <linux/sysfs.h>
27#include <linux/kernel.h>
28#include <linux/slab.h>
29#include <linux/vmalloc.h>
30#include <linux/elf.h>
31#include <linux/proc_fs.h>
32#include <linux/security.h>
33#include <linux/seq_file.h>
34#include <linux/syscalls.h>
35#include <linux/fcntl.h>
36#include <linux/rcupdate.h>
37#include <linux/capability.h>
38#include <linux/cpu.h>
39#include <linux/moduleparam.h>
40#include <linux/errno.h>
41#include <linux/err.h>
42#include <linux/vermagic.h>
43#include <linux/notifier.h>
44#include <linux/sched.h>
45#include <linux/device.h>
46#include <linux/string.h>
47#include <linux/mutex.h>
48#include <linux/rculist.h>
49#include <asm/uaccess.h>
50#include <asm/cacheflush.h>
51#include <asm/mmu_context.h>
52#include <linux/license.h>
53#include <asm/sections.h>
54#include <linux/tracepoint.h>
55#include <linux/ftrace.h>
56#include <linux/livepatch.h>
57#include <linux/async.h>
58#include <linux/percpu.h>
59#include <linux/kmemleak.h>
60#include <linux/jump_label.h>
61#include <linux/pfn.h>
62#include <linux/bsearch.h>
63#include <uapi/linux/module.h>
64#include "module-internal.h"
65
66#define CREATE_TRACE_POINTS
67#include <trace/events/module.h>
68
69#ifndef ARCH_SHF_SMALL
70#define ARCH_SHF_SMALL 0
71#endif
72
73/*
74 * Modules' sections will be aligned on page boundaries
75 * to ensure complete separation of code and data, but
76 * only when CONFIG_DEBUG_SET_MODULE_RONX=y
77 */
78#ifdef CONFIG_DEBUG_SET_MODULE_RONX
79# define debug_align(X) ALIGN(X, PAGE_SIZE)
80#else
81# define debug_align(X) (X)
82#endif
83
84/* If this is set, the section belongs in the init part of the module */
85#define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
86
87/*
88 * Mutex protects:
89 * 1) List of modules (also safely readable with preempt_disable),
90 * 2) module_use links,
91 * 3) module_addr_min/module_addr_max.
92 * (delete and add uses RCU list operations). */
93DEFINE_MUTEX(module_mutex);
94EXPORT_SYMBOL_GPL(module_mutex);
95static LIST_HEAD(modules);
96
97#ifdef CONFIG_MODULES_TREE_LOOKUP
98
99/*
100 * Use a latched RB-tree for __module_address(); this allows us to use
101 * RCU-sched lookups of the address from any context.
102 *
103 * This is conditional on PERF_EVENTS || TRACING because those can really hit
104 * __module_address() hard by doing a lot of stack unwinding; potentially from
105 * NMI context.
106 */
107
108static __always_inline unsigned long __mod_tree_val(struct latch_tree_node *n)
109{
110 struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
111
112 return (unsigned long)layout->base;
113}
114
115static __always_inline unsigned long __mod_tree_size(struct latch_tree_node *n)
116{
117 struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
118
119 return (unsigned long)layout->size;
120}
121
122static __always_inline bool
123mod_tree_less(struct latch_tree_node *a, struct latch_tree_node *b)
124{
125 return __mod_tree_val(a) < __mod_tree_val(b);
126}
127
128static __always_inline int
129mod_tree_comp(void *key, struct latch_tree_node *n)
130{
131 unsigned long val = (unsigned long)key;
132 unsigned long start, end;
133
134 start = __mod_tree_val(n);
135 if (val < start)
136 return -1;
137
138 end = start + __mod_tree_size(n);
139 if (val >= end)
140 return 1;
141
142 return 0;
143}
144
145static const struct latch_tree_ops mod_tree_ops = {
146 .less = mod_tree_less,
147 .comp = mod_tree_comp,
148};
149
150static struct mod_tree_root {
151 struct latch_tree_root root;
152 unsigned long addr_min;
153 unsigned long addr_max;
154} mod_tree __cacheline_aligned = {
155 .addr_min = -1UL,
156};
157
158#define module_addr_min mod_tree.addr_min
159#define module_addr_max mod_tree.addr_max
160
161static noinline void __mod_tree_insert(struct mod_tree_node *node)
162{
163 latch_tree_insert(&node->node, &mod_tree.root, &mod_tree_ops);
164}
165
166static void __mod_tree_remove(struct mod_tree_node *node)
167{
168 latch_tree_erase(&node->node, &mod_tree.root, &mod_tree_ops);
169}
170
171/*
172 * These modifications: insert, remove_init and remove; are serialized by the
173 * module_mutex.
174 */
175static void mod_tree_insert(struct module *mod)
176{
177 mod->core_layout.mtn.mod = mod;
178 mod->init_layout.mtn.mod = mod;
179
180 __mod_tree_insert(&mod->core_layout.mtn);
181 if (mod->init_layout.size)
182 __mod_tree_insert(&mod->init_layout.mtn);
183}
184
185static void mod_tree_remove_init(struct module *mod)
186{
187 if (mod->init_layout.size)
188 __mod_tree_remove(&mod->init_layout.mtn);
189}
190
191static void mod_tree_remove(struct module *mod)
192{
193 __mod_tree_remove(&mod->core_layout.mtn);
194 mod_tree_remove_init(mod);
195}
196
197static struct module *mod_find(unsigned long addr)
198{
199 struct latch_tree_node *ltn;
200
201 ltn = latch_tree_find((void *)addr, &mod_tree.root, &mod_tree_ops);
202 if (!ltn)
203 return NULL;
204
205 return container_of(ltn, struct mod_tree_node, node)->mod;
206}
207
208#else /* MODULES_TREE_LOOKUP */
209
210static unsigned long module_addr_min = -1UL, module_addr_max = 0;
211
212static void mod_tree_insert(struct module *mod) { }
213static void mod_tree_remove_init(struct module *mod) { }
214static void mod_tree_remove(struct module *mod) { }
215
216static struct module *mod_find(unsigned long addr)
217{
218 struct module *mod;
219
220 list_for_each_entry_rcu(mod, &modules, list) {
221 if (within_module(addr, mod))
222 return mod;
223 }
224
225 return NULL;
226}
227
228#endif /* MODULES_TREE_LOOKUP */
229
230/*
231 * Bounds of module text, for speeding up __module_address.
232 * Protected by module_mutex.
233 */
234static void __mod_update_bounds(void *base, unsigned int size)
235{
236 unsigned long min = (unsigned long)base;
237 unsigned long max = min + size;
238
239 if (min < module_addr_min)
240 module_addr_min = min;
241 if (max > module_addr_max)
242 module_addr_max = max;
243}
244
245static void mod_update_bounds(struct module *mod)
246{
247 __mod_update_bounds(mod->core_layout.base, mod->core_layout.size);
248 if (mod->init_layout.size)
249 __mod_update_bounds(mod->init_layout.base, mod->init_layout.size);
250}
251
252#ifdef CONFIG_KGDB_KDB
253struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
254#endif /* CONFIG_KGDB_KDB */
255
256static void module_assert_mutex(void)
257{
258 lockdep_assert_held(&module_mutex);
259}
260
261static void module_assert_mutex_or_preempt(void)
262{
263#ifdef CONFIG_LOCKDEP
264 if (unlikely(!debug_locks))
265 return;
266
267 WARN_ON(!rcu_read_lock_sched_held() &&
268 !lockdep_is_held(&module_mutex));
269#endif
270}
271
272static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE);
273#ifndef CONFIG_MODULE_SIG_FORCE
274module_param(sig_enforce, bool_enable_only, 0644);
275#endif /* !CONFIG_MODULE_SIG_FORCE */
276
277/* Block module loading/unloading? */
278int modules_disabled = 0;
279core_param(nomodule, modules_disabled, bint, 0);
280
281/* Waiting for a module to finish initializing? */
282static DECLARE_WAIT_QUEUE_HEAD(module_wq);
283
284static BLOCKING_NOTIFIER_HEAD(module_notify_list);
285
286int register_module_notifier(struct notifier_block *nb)
287{
288 return blocking_notifier_chain_register(&module_notify_list, nb);
289}
290EXPORT_SYMBOL(register_module_notifier);
291
292int unregister_module_notifier(struct notifier_block *nb)
293{
294 return blocking_notifier_chain_unregister(&module_notify_list, nb);
295}
296EXPORT_SYMBOL(unregister_module_notifier);
297
298struct load_info {
299 Elf_Ehdr *hdr;
300 unsigned long len;
301 Elf_Shdr *sechdrs;
302 char *secstrings, *strtab;
303 unsigned long symoffs, stroffs;
304 struct _ddebug *debug;
305 unsigned int num_debug;
306 bool sig_ok;
307#ifdef CONFIG_KALLSYMS
308 unsigned long mod_kallsyms_init_off;
309#endif
310 struct {
311 unsigned int sym, str, mod, vers, info, pcpu;
312 } index;
313};
314
315/* We require a truly strong try_module_get(): 0 means failure due to
316 ongoing or failed initialization etc. */
317static inline int strong_try_module_get(struct module *mod)
318{
319 BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED);
320 if (mod && mod->state == MODULE_STATE_COMING)
321 return -EBUSY;
322 if (try_module_get(mod))
323 return 0;
324 else
325 return -ENOENT;
326}
327
328static inline void add_taint_module(struct module *mod, unsigned flag,
329 enum lockdep_ok lockdep_ok)
330{
331 add_taint(flag, lockdep_ok);
332 mod->taints |= (1U << flag);
333}
334
335/*
336 * A thread that wants to hold a reference to a module only while it
337 * is running can call this to safely exit. nfsd and lockd use this.
338 */
339void __module_put_and_exit(struct module *mod, long code)
340{
341 module_put(mod);
342 do_exit(code);
343}
344EXPORT_SYMBOL(__module_put_and_exit);
345
346/* Find a module section: 0 means not found. */
347static unsigned int find_sec(const struct load_info *info, const char *name)
348{
349 unsigned int i;
350
351 for (i = 1; i < info->hdr->e_shnum; i++) {
352 Elf_Shdr *shdr = &info->sechdrs[i];
353 /* Alloc bit cleared means "ignore it." */
354 if ((shdr->sh_flags & SHF_ALLOC)
355 && strcmp(info->secstrings + shdr->sh_name, name) == 0)
356 return i;
357 }
358 return 0;
359}
360
361/* Find a module section, or NULL. */
362static void *section_addr(const struct load_info *info, const char *name)
363{
364 /* Section 0 has sh_addr 0. */
365 return (void *)info->sechdrs[find_sec(info, name)].sh_addr;
366}
367
368/* Find a module section, or NULL. Fill in number of "objects" in section. */
369static void *section_objs(const struct load_info *info,
370 const char *name,
371 size_t object_size,
372 unsigned int *num)
373{
374 unsigned int sec = find_sec(info, name);
375
376 /* Section 0 has sh_addr 0 and sh_size 0. */
377 *num = info->sechdrs[sec].sh_size / object_size;
378 return (void *)info->sechdrs[sec].sh_addr;
379}
380
381/* Provided by the linker */
382extern const struct kernel_symbol __start___ksymtab[];
383extern const struct kernel_symbol __stop___ksymtab[];
384extern const struct kernel_symbol __start___ksymtab_gpl[];
385extern const struct kernel_symbol __stop___ksymtab_gpl[];
386extern const struct kernel_symbol __start___ksymtab_gpl_future[];
387extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
388extern const unsigned long __start___kcrctab[];
389extern const unsigned long __start___kcrctab_gpl[];
390extern const unsigned long __start___kcrctab_gpl_future[];
391#ifdef CONFIG_UNUSED_SYMBOLS
392extern const struct kernel_symbol __start___ksymtab_unused[];
393extern const struct kernel_symbol __stop___ksymtab_unused[];
394extern const struct kernel_symbol __start___ksymtab_unused_gpl[];
395extern const struct kernel_symbol __stop___ksymtab_unused_gpl[];
396extern const unsigned long __start___kcrctab_unused[];
397extern const unsigned long __start___kcrctab_unused_gpl[];
398#endif
399
400#ifndef CONFIG_MODVERSIONS
401#define symversion(base, idx) NULL
402#else
403#define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
404#endif
405
406static bool each_symbol_in_section(const struct symsearch *arr,
407 unsigned int arrsize,
408 struct module *owner,
409 bool (*fn)(const struct symsearch *syms,
410 struct module *owner,
411 void *data),
412 void *data)
413{
414 unsigned int j;
415
416 for (j = 0; j < arrsize; j++) {
417 if (fn(&arr[j], owner, data))
418 return true;
419 }
420
421 return false;
422}
423
424/* Returns true as soon as fn returns true, otherwise false. */
425bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
426 struct module *owner,
427 void *data),
428 void *data)
429{
430 struct module *mod;
431 static const struct symsearch arr[] = {
432 { __start___ksymtab, __stop___ksymtab, __start___kcrctab,
433 NOT_GPL_ONLY, false },
434 { __start___ksymtab_gpl, __stop___ksymtab_gpl,
435 __start___kcrctab_gpl,
436 GPL_ONLY, false },
437 { __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future,
438 __start___kcrctab_gpl_future,
439 WILL_BE_GPL_ONLY, false },
440#ifdef CONFIG_UNUSED_SYMBOLS
441 { __start___ksymtab_unused, __stop___ksymtab_unused,
442 __start___kcrctab_unused,
443 NOT_GPL_ONLY, true },
444 { __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl,
445 __start___kcrctab_unused_gpl,
446 GPL_ONLY, true },
447#endif
448 };
449
450 module_assert_mutex_or_preempt();
451
452 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data))
453 return true;
454
455 list_for_each_entry_rcu(mod, &modules, list) {
456 struct symsearch arr[] = {
457 { mod->syms, mod->syms + mod->num_syms, mod->crcs,
458 NOT_GPL_ONLY, false },
459 { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
460 mod->gpl_crcs,
461 GPL_ONLY, false },
462 { mod->gpl_future_syms,
463 mod->gpl_future_syms + mod->num_gpl_future_syms,
464 mod->gpl_future_crcs,
465 WILL_BE_GPL_ONLY, false },
466#ifdef CONFIG_UNUSED_SYMBOLS
467 { mod->unused_syms,
468 mod->unused_syms + mod->num_unused_syms,
469 mod->unused_crcs,
470 NOT_GPL_ONLY, true },
471 { mod->unused_gpl_syms,
472 mod->unused_gpl_syms + mod->num_unused_gpl_syms,
473 mod->unused_gpl_crcs,
474 GPL_ONLY, true },
475#endif
476 };
477
478 if (mod->state == MODULE_STATE_UNFORMED)
479 continue;
480
481 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data))
482 return true;
483 }
484 return false;
485}
486EXPORT_SYMBOL_GPL(each_symbol_section);
487
488struct find_symbol_arg {
489 /* Input */
490 const char *name;
491 bool gplok;
492 bool warn;
493
494 /* Output */
495 struct module *owner;
496 const unsigned long *crc;
497 const struct kernel_symbol *sym;
498};
499
500static bool check_symbol(const struct symsearch *syms,
501 struct module *owner,
502 unsigned int symnum, void *data)
503{
504 struct find_symbol_arg *fsa = data;
505
506 if (!fsa->gplok) {
507 if (syms->licence == GPL_ONLY)
508 return false;
509 if (syms->licence == WILL_BE_GPL_ONLY && fsa->warn) {
510 pr_warn("Symbol %s is being used by a non-GPL module, "
511 "which will not be allowed in the future\n",
512 fsa->name);
513 }
514 }
515
516#ifdef CONFIG_UNUSED_SYMBOLS
517 if (syms->unused && fsa->warn) {
518 pr_warn("Symbol %s is marked as UNUSED, however this module is "
519 "using it.\n", fsa->name);
520 pr_warn("This symbol will go away in the future.\n");
521 pr_warn("Please evaluate if this is the right api to use and "
522 "if it really is, submit a report to the linux kernel "
523 "mailing list together with submitting your code for "
524 "inclusion.\n");
525 }
526#endif
527
528 fsa->owner = owner;
529 fsa->crc = symversion(syms->crcs, symnum);
530 fsa->sym = &syms->start[symnum];
531 return true;
532}
533
534static int cmp_name(const void *va, const void *vb)
535{
536 const char *a;
537 const struct kernel_symbol *b;
538 a = va; b = vb;
539 return strcmp(a, b->name);
540}
541
542static bool find_symbol_in_section(const struct symsearch *syms,
543 struct module *owner,
544 void *data)
545{
546 struct find_symbol_arg *fsa = data;
547 struct kernel_symbol *sym;
548
549 sym = bsearch(fsa->name, syms->start, syms->stop - syms->start,
550 sizeof(struct kernel_symbol), cmp_name);
551
552 if (sym != NULL && check_symbol(syms, owner, sym - syms->start, data))
553 return true;
554
555 return false;
556}
557
558/* Find a symbol and return it, along with, (optional) crc and
559 * (optional) module which owns it. Needs preempt disabled or module_mutex. */
560const struct kernel_symbol *find_symbol(const char *name,
561 struct module **owner,
562 const unsigned long **crc,
563 bool gplok,
564 bool warn)
565{
566 struct find_symbol_arg fsa;
567
568 fsa.name = name;
569 fsa.gplok = gplok;
570 fsa.warn = warn;
571
572 if (each_symbol_section(find_symbol_in_section, &fsa)) {
573 if (owner)
574 *owner = fsa.owner;
575 if (crc)
576 *crc = fsa.crc;
577 return fsa.sym;
578 }
579
580 pr_debug("Failed to find symbol %s\n", name);
581 return NULL;
582}
583EXPORT_SYMBOL_GPL(find_symbol);
584
585/*
586 * Search for module by name: must hold module_mutex (or preempt disabled
587 * for read-only access).
588 */
589static struct module *find_module_all(const char *name, size_t len,
590 bool even_unformed)
591{
592 struct module *mod;
593
594 module_assert_mutex_or_preempt();
595
596 list_for_each_entry(mod, &modules, list) {
597 if (!even_unformed && mod->state == MODULE_STATE_UNFORMED)
598 continue;
599 if (strlen(mod->name) == len && !memcmp(mod->name, name, len))
600 return mod;
601 }
602 return NULL;
603}
604
605struct module *find_module(const char *name)
606{
607 module_assert_mutex();
608 return find_module_all(name, strlen(name), false);
609}
610EXPORT_SYMBOL_GPL(find_module);
611
612#ifdef CONFIG_SMP
613
614static inline void __percpu *mod_percpu(struct module *mod)
615{
616 return mod->percpu;
617}
618
619static int percpu_modalloc(struct module *mod, struct load_info *info)
620{
621 Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu];
622 unsigned long align = pcpusec->sh_addralign;
623
624 if (!pcpusec->sh_size)
625 return 0;
626
627 if (align > PAGE_SIZE) {
628 pr_warn("%s: per-cpu alignment %li > %li\n",
629 mod->name, align, PAGE_SIZE);
630 align = PAGE_SIZE;
631 }
632
633 mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align);
634 if (!mod->percpu) {
635 pr_warn("%s: Could not allocate %lu bytes percpu data\n",
636 mod->name, (unsigned long)pcpusec->sh_size);
637 return -ENOMEM;
638 }
639 mod->percpu_size = pcpusec->sh_size;
640 return 0;
641}
642
643static void percpu_modfree(struct module *mod)
644{
645 free_percpu(mod->percpu);
646}
647
648static unsigned int find_pcpusec(struct load_info *info)
649{
650 return find_sec(info, ".data..percpu");
651}
652
653static void percpu_modcopy(struct module *mod,
654 const void *from, unsigned long size)
655{
656 int cpu;
657
658 for_each_possible_cpu(cpu)
659 memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
660}
661
662/**
663 * is_module_percpu_address - test whether address is from module static percpu
664 * @addr: address to test
665 *
666 * Test whether @addr belongs to module static percpu area.
667 *
668 * RETURNS:
669 * %true if @addr is from module static percpu area
670 */
671bool is_module_percpu_address(unsigned long 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
686 if ((void *)addr >= start &&
687 (void *)addr < start + mod->percpu_size) {
688 preempt_enable();
689 return true;
690 }
691 }
692 }
693
694 preempt_enable();
695 return false;
696}
697
698#else /* ... !CONFIG_SMP */
699
700static inline void __percpu *mod_percpu(struct module *mod)
701{
702 return NULL;
703}
704static int percpu_modalloc(struct module *mod, struct load_info *info)
705{
706 /* UP modules shouldn't have this section: ENOMEM isn't quite right */
707 if (info->sechdrs[info->index.pcpu].sh_size != 0)
708 return -ENOMEM;
709 return 0;
710}
711static inline void percpu_modfree(struct module *mod)
712{
713}
714static unsigned int find_pcpusec(struct load_info *info)
715{
716 return 0;
717}
718static inline void percpu_modcopy(struct module *mod,
719 const void *from, unsigned long size)
720{
721 /* pcpusec should be 0, and size of that section should be 0. */
722 BUG_ON(size != 0);
723}
724bool is_module_percpu_address(unsigned long addr)
725{
726 return false;
727}
728
729#endif /* CONFIG_SMP */
730
731#define MODINFO_ATTR(field) \
732static void setup_modinfo_##field(struct module *mod, const char *s) \
733{ \
734 mod->field = kstrdup(s, GFP_KERNEL); \
735} \
736static ssize_t show_modinfo_##field(struct module_attribute *mattr, \
737 struct module_kobject *mk, char *buffer) \
738{ \
739 return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field); \
740} \
741static int modinfo_##field##_exists(struct module *mod) \
742{ \
743 return mod->field != NULL; \
744} \
745static void free_modinfo_##field(struct module *mod) \
746{ \
747 kfree(mod->field); \
748 mod->field = NULL; \
749} \
750static struct module_attribute modinfo_##field = { \
751 .attr = { .name = __stringify(field), .mode = 0444 }, \
752 .show = show_modinfo_##field, \
753 .setup = setup_modinfo_##field, \
754 .test = modinfo_##field##_exists, \
755 .free = free_modinfo_##field, \
756};
757
758MODINFO_ATTR(version);
759MODINFO_ATTR(srcversion);
760
761static char last_unloaded_module[MODULE_NAME_LEN+1];
762
763#ifdef CONFIG_MODULE_UNLOAD
764
765EXPORT_TRACEPOINT_SYMBOL(module_get);
766
767/* MODULE_REF_BASE is the base reference count by kmodule loader. */
768#define MODULE_REF_BASE 1
769
770/* Init the unload section of the module. */
771static int module_unload_init(struct module *mod)
772{
773 /*
774 * Initialize reference counter to MODULE_REF_BASE.
775 * refcnt == 0 means module is going.
776 */
777 atomic_set(&mod->refcnt, MODULE_REF_BASE);
778
779 INIT_LIST_HEAD(&mod->source_list);
780 INIT_LIST_HEAD(&mod->target_list);
781
782 /* Hold reference count during initialization. */
783 atomic_inc(&mod->refcnt);
784
785 return 0;
786}
787
788/* Does a already use b? */
789static int already_uses(struct module *a, struct module *b)
790{
791 struct module_use *use;
792
793 list_for_each_entry(use, &b->source_list, source_list) {
794 if (use->source == a) {
795 pr_debug("%s uses %s!\n", a->name, b->name);
796 return 1;
797 }
798 }
799 pr_debug("%s does not use %s!\n", a->name, b->name);
800 return 0;
801}
802
803/*
804 * Module a uses b
805 * - we add 'a' as a "source", 'b' as a "target" of module use
806 * - the module_use is added to the list of 'b' sources (so
807 * 'b' can walk the list to see who sourced them), and of 'a'
808 * targets (so 'a' can see what modules it targets).
809 */
810static int add_module_usage(struct module *a, struct module *b)
811{
812 struct module_use *use;
813
814 pr_debug("Allocating new usage for %s.\n", a->name);
815 use = kmalloc(sizeof(*use), GFP_ATOMIC);
816 if (!use) {
817 pr_warn("%s: out of memory loading\n", a->name);
818 return -ENOMEM;
819 }
820
821 use->source = a;
822 use->target = b;
823 list_add(&use->source_list, &b->source_list);
824 list_add(&use->target_list, &a->target_list);
825 return 0;
826}
827
828/* Module a uses b: caller needs module_mutex() */
829int ref_module(struct module *a, struct module *b)
830{
831 int err;
832
833 if (b == NULL || already_uses(a, b))
834 return 0;
835
836 /* If module isn't available, we fail. */
837 err = strong_try_module_get(b);
838 if (err)
839 return err;
840
841 err = add_module_usage(a, b);
842 if (err) {
843 module_put(b);
844 return err;
845 }
846 return 0;
847}
848EXPORT_SYMBOL_GPL(ref_module);
849
850/* Clear the unload stuff of the module. */
851static void module_unload_free(struct module *mod)
852{
853 struct module_use *use, *tmp;
854
855 mutex_lock(&module_mutex);
856 list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
857 struct module *i = use->target;
858 pr_debug("%s unusing %s\n", mod->name, i->name);
859 module_put(i);
860 list_del(&use->source_list);
861 list_del(&use->target_list);
862 kfree(use);
863 }
864 mutex_unlock(&module_mutex);
865}
866
867#ifdef CONFIG_MODULE_FORCE_UNLOAD
868static inline int try_force_unload(unsigned int flags)
869{
870 int ret = (flags & O_TRUNC);
871 if (ret)
872 add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE);
873 return ret;
874}
875#else
876static inline int try_force_unload(unsigned int flags)
877{
878 return 0;
879}
880#endif /* CONFIG_MODULE_FORCE_UNLOAD */
881
882/* Try to release refcount of module, 0 means success. */
883static int try_release_module_ref(struct module *mod)
884{
885 int ret;
886
887 /* Try to decrement refcnt which we set at loading */
888 ret = atomic_sub_return(MODULE_REF_BASE, &mod->refcnt);
889 BUG_ON(ret < 0);
890 if (ret)
891 /* Someone can put this right now, recover with checking */
892 ret = atomic_add_unless(&mod->refcnt, MODULE_REF_BASE, 0);
893
894 return ret;
895}
896
897static int try_stop_module(struct module *mod, int flags, int *forced)
898{
899 /* If it's not unused, quit unless we're forcing. */
900 if (try_release_module_ref(mod) != 0) {
901 *forced = try_force_unload(flags);
902 if (!(*forced))
903 return -EWOULDBLOCK;
904 }
905
906 /* Mark it as dying. */
907 mod->state = MODULE_STATE_GOING;
908
909 return 0;
910}
911
912/**
913 * module_refcount - return the refcount or -1 if unloading
914 *
915 * @mod: the module we're checking
916 *
917 * Returns:
918 * -1 if the module is in the process of unloading
919 * otherwise the number of references in the kernel to the module
920 */
921int module_refcount(struct module *mod)
922{
923 return atomic_read(&mod->refcnt) - MODULE_REF_BASE;
924}
925EXPORT_SYMBOL(module_refcount);
926
927/* This exists whether we can unload or not */
928static void free_module(struct module *mod);
929
930SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
931 unsigned int, flags)
932{
933 struct module *mod;
934 char name[MODULE_NAME_LEN];
935 int ret, forced = 0;
936
937 if (!capable(CAP_SYS_MODULE) || modules_disabled)
938 return -EPERM;
939
940 if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
941 return -EFAULT;
942 name[MODULE_NAME_LEN-1] = '\0';
943
944 if (mutex_lock_interruptible(&module_mutex) != 0)
945 return -EINTR;
946
947 mod = find_module(name);
948 if (!mod) {
949 ret = -ENOENT;
950 goto out;
951 }
952
953 if (!list_empty(&mod->source_list)) {
954 /* Other modules depend on us: get rid of them first. */
955 ret = -EWOULDBLOCK;
956 goto out;
957 }
958
959 /* Doing init or already dying? */
960 if (mod->state != MODULE_STATE_LIVE) {
961 /* FIXME: if (force), slam module count damn the torpedoes */
962 pr_debug("%s already dying\n", mod->name);
963 ret = -EBUSY;
964 goto out;
965 }
966
967 /* If it has an init func, it must have an exit func to unload */
968 if (mod->init && !mod->exit) {
969 forced = try_force_unload(flags);
970 if (!forced) {
971 /* This module can't be removed */
972 ret = -EBUSY;
973 goto out;
974 }
975 }
976
977 /* Stop the machine so refcounts can't move and disable module. */
978 ret = try_stop_module(mod, flags, &forced);
979 if (ret != 0)
980 goto out;
981
982 mutex_unlock(&module_mutex);
983 /* Final destruction now no one is using it. */
984 if (mod->exit != NULL)
985 mod->exit();
986 blocking_notifier_call_chain(&module_notify_list,
987 MODULE_STATE_GOING, mod);
988 klp_module_going(mod);
989 ftrace_release_mod(mod);
990
991 async_synchronize_full();
992
993 /* Store the name of the last unloaded module for diagnostic purposes */
994 strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
995
996 free_module(mod);
997 return 0;
998out:
999 mutex_unlock(&module_mutex);
1000 return ret;
1001}
1002
1003static inline void print_unload_info(struct seq_file *m, struct module *mod)
1004{
1005 struct module_use *use;
1006 int printed_something = 0;
1007
1008 seq_printf(m, " %i ", module_refcount(mod));
1009
1010 /*
1011 * Always include a trailing , so userspace can differentiate
1012 * between this and the old multi-field proc format.
1013 */
1014 list_for_each_entry(use, &mod->source_list, source_list) {
1015 printed_something = 1;
1016 seq_printf(m, "%s,", use->source->name);
1017 }
1018
1019 if (mod->init != NULL && mod->exit == NULL) {
1020 printed_something = 1;
1021 seq_puts(m, "[permanent],");
1022 }
1023
1024 if (!printed_something)
1025 seq_puts(m, "-");
1026}
1027
1028void __symbol_put(const char *symbol)
1029{
1030 struct module *owner;
1031
1032 preempt_disable();
1033 if (!find_symbol(symbol, &owner, NULL, true, false))
1034 BUG();
1035 module_put(owner);
1036 preempt_enable();
1037}
1038EXPORT_SYMBOL(__symbol_put);
1039
1040/* Note this assumes addr is a function, which it currently always is. */
1041void symbol_put_addr(void *addr)
1042{
1043 struct module *modaddr;
1044 unsigned long a = (unsigned long)dereference_function_descriptor(addr);
1045
1046 if (core_kernel_text(a))
1047 return;
1048
1049 /*
1050 * Even though we hold a reference on the module; we still need to
1051 * disable preemption in order to safely traverse the data structure.
1052 */
1053 preempt_disable();
1054 modaddr = __module_text_address(a);
1055 BUG_ON(!modaddr);
1056 module_put(modaddr);
1057 preempt_enable();
1058}
1059EXPORT_SYMBOL_GPL(symbol_put_addr);
1060
1061static ssize_t show_refcnt(struct module_attribute *mattr,
1062 struct module_kobject *mk, char *buffer)
1063{
1064 return sprintf(buffer, "%i\n", module_refcount(mk->mod));
1065}
1066
1067static struct module_attribute modinfo_refcnt =
1068 __ATTR(refcnt, 0444, show_refcnt, NULL);
1069
1070void __module_get(struct module *module)
1071{
1072 if (module) {
1073 preempt_disable();
1074 atomic_inc(&module->refcnt);
1075 trace_module_get(module, _RET_IP_);
1076 preempt_enable();
1077 }
1078}
1079EXPORT_SYMBOL(__module_get);
1080
1081bool try_module_get(struct module *module)
1082{
1083 bool ret = true;
1084
1085 if (module) {
1086 preempt_disable();
1087 /* Note: here, we can fail to get a reference */
1088 if (likely(module_is_live(module) &&
1089 atomic_inc_not_zero(&module->refcnt) != 0))
1090 trace_module_get(module, _RET_IP_);
1091 else
1092 ret = false;
1093
1094 preempt_enable();
1095 }
1096 return ret;
1097}
1098EXPORT_SYMBOL(try_module_get);
1099
1100void module_put(struct module *module)
1101{
1102 int ret;
1103
1104 if (module) {
1105 preempt_disable();
1106 ret = atomic_dec_if_positive(&module->refcnt);
1107 WARN_ON(ret < 0); /* Failed to put refcount */
1108 trace_module_put(module, _RET_IP_);
1109 preempt_enable();
1110 }
1111}
1112EXPORT_SYMBOL(module_put);
1113
1114#else /* !CONFIG_MODULE_UNLOAD */
1115static inline void print_unload_info(struct seq_file *m, struct module *mod)
1116{
1117 /* We don't know the usage count, or what modules are using. */
1118 seq_puts(m, " - -");
1119}
1120
1121static inline void module_unload_free(struct module *mod)
1122{
1123}
1124
1125int ref_module(struct module *a, struct module *b)
1126{
1127 return strong_try_module_get(b);
1128}
1129EXPORT_SYMBOL_GPL(ref_module);
1130
1131static inline int module_unload_init(struct module *mod)
1132{
1133 return 0;
1134}
1135#endif /* CONFIG_MODULE_UNLOAD */
1136
1137static size_t module_flags_taint(struct module *mod, char *buf)
1138{
1139 size_t l = 0;
1140
1141 if (mod->taints & (1 << TAINT_PROPRIETARY_MODULE))
1142 buf[l++] = 'P';
1143 if (mod->taints & (1 << TAINT_OOT_MODULE))
1144 buf[l++] = 'O';
1145 if (mod->taints & (1 << TAINT_FORCED_MODULE))
1146 buf[l++] = 'F';
1147 if (mod->taints & (1 << TAINT_CRAP))
1148 buf[l++] = 'C';
1149 if (mod->taints & (1 << TAINT_UNSIGNED_MODULE))
1150 buf[l++] = 'E';
1151 /*
1152 * TAINT_FORCED_RMMOD: could be added.
1153 * TAINT_CPU_OUT_OF_SPEC, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't
1154 * apply to modules.
1155 */
1156 return l;
1157}
1158
1159static ssize_t show_initstate(struct module_attribute *mattr,
1160 struct module_kobject *mk, char *buffer)
1161{
1162 const char *state = "unknown";
1163
1164 switch (mk->mod->state) {
1165 case MODULE_STATE_LIVE:
1166 state = "live";
1167 break;
1168 case MODULE_STATE_COMING:
1169 state = "coming";
1170 break;
1171 case MODULE_STATE_GOING:
1172 state = "going";
1173 break;
1174 default:
1175 BUG();
1176 }
1177 return sprintf(buffer, "%s\n", state);
1178}
1179
1180static struct module_attribute modinfo_initstate =
1181 __ATTR(initstate, 0444, show_initstate, NULL);
1182
1183static ssize_t store_uevent(struct module_attribute *mattr,
1184 struct module_kobject *mk,
1185 const char *buffer, size_t count)
1186{
1187 enum kobject_action action;
1188
1189 if (kobject_action_type(buffer, count, &action) == 0)
1190 kobject_uevent(&mk->kobj, action);
1191 return count;
1192}
1193
1194struct module_attribute module_uevent =
1195 __ATTR(uevent, 0200, NULL, store_uevent);
1196
1197static ssize_t show_coresize(struct module_attribute *mattr,
1198 struct module_kobject *mk, char *buffer)
1199{
1200 return sprintf(buffer, "%u\n", mk->mod->core_layout.size);
1201}
1202
1203static struct module_attribute modinfo_coresize =
1204 __ATTR(coresize, 0444, show_coresize, NULL);
1205
1206static ssize_t show_initsize(struct module_attribute *mattr,
1207 struct module_kobject *mk, char *buffer)
1208{
1209 return sprintf(buffer, "%u\n", mk->mod->init_layout.size);
1210}
1211
1212static struct module_attribute modinfo_initsize =
1213 __ATTR(initsize, 0444, show_initsize, NULL);
1214
1215static ssize_t show_taint(struct module_attribute *mattr,
1216 struct module_kobject *mk, char *buffer)
1217{
1218 size_t l;
1219
1220 l = module_flags_taint(mk->mod, buffer);
1221 buffer[l++] = '\n';
1222 return l;
1223}
1224
1225static struct module_attribute modinfo_taint =
1226 __ATTR(taint, 0444, show_taint, NULL);
1227
1228static struct module_attribute *modinfo_attrs[] = {
1229 &module_uevent,
1230 &modinfo_version,
1231 &modinfo_srcversion,
1232 &modinfo_initstate,
1233 &modinfo_coresize,
1234 &modinfo_initsize,
1235 &modinfo_taint,
1236#ifdef CONFIG_MODULE_UNLOAD
1237 &modinfo_refcnt,
1238#endif
1239 NULL,
1240};
1241
1242static const char vermagic[] = VERMAGIC_STRING;
1243
1244static int try_to_force_load(struct module *mod, const char *reason)
1245{
1246#ifdef CONFIG_MODULE_FORCE_LOAD
1247 if (!test_taint(TAINT_FORCED_MODULE))
1248 pr_warn("%s: %s: kernel tainted.\n", mod->name, reason);
1249 add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
1250 return 0;
1251#else
1252 return -ENOEXEC;
1253#endif
1254}
1255
1256#ifdef CONFIG_MODVERSIONS
1257/* If the arch applies (non-zero) relocations to kernel kcrctab, unapply it. */
1258static unsigned long maybe_relocated(unsigned long crc,
1259 const struct module *crc_owner)
1260{
1261#ifdef ARCH_RELOCATES_KCRCTAB
1262 if (crc_owner == NULL)
1263 return crc - (unsigned long)reloc_start;
1264#endif
1265 return crc;
1266}
1267
1268static int check_version(Elf_Shdr *sechdrs,
1269 unsigned int versindex,
1270 const char *symname,
1271 struct module *mod,
1272 const unsigned long *crc,
1273 const struct module *crc_owner)
1274{
1275 unsigned int i, num_versions;
1276 struct modversion_info *versions;
1277
1278 /* Exporting module didn't supply crcs? OK, we're already tainted. */
1279 if (!crc)
1280 return 1;
1281
1282 /* No versions at all? modprobe --force does this. */
1283 if (versindex == 0)
1284 return try_to_force_load(mod, symname) == 0;
1285
1286 versions = (void *) sechdrs[versindex].sh_addr;
1287 num_versions = sechdrs[versindex].sh_size
1288 / sizeof(struct modversion_info);
1289
1290 for (i = 0; i < num_versions; i++) {
1291 if (strcmp(versions[i].name, symname) != 0)
1292 continue;
1293
1294 if (versions[i].crc == maybe_relocated(*crc, crc_owner))
1295 return 1;
1296 pr_debug("Found checksum %lX vs module %lX\n",
1297 maybe_relocated(*crc, crc_owner), versions[i].crc);
1298 goto bad_version;
1299 }
1300
1301 pr_warn("%s: no symbol version for %s\n", mod->name, symname);
1302 return 0;
1303
1304bad_version:
1305 pr_warn("%s: disagrees about version of symbol %s\n",
1306 mod->name, symname);
1307 return 0;
1308}
1309
1310static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1311 unsigned int versindex,
1312 struct module *mod)
1313{
1314 const unsigned long *crc;
1315
1316 /*
1317 * Since this should be found in kernel (which can't be removed), no
1318 * locking is necessary -- use preempt_disable() to placate lockdep.
1319 */
1320 preempt_disable();
1321 if (!find_symbol(VMLINUX_SYMBOL_STR(module_layout), NULL,
1322 &crc, true, false)) {
1323 preempt_enable();
1324 BUG();
1325 }
1326 preempt_enable();
1327 return check_version(sechdrs, versindex,
1328 VMLINUX_SYMBOL_STR(module_layout), mod, crc,
1329 NULL);
1330}
1331
1332/* First part is kernel version, which we ignore if module has crcs. */
1333static inline int same_magic(const char *amagic, const char *bmagic,
1334 bool has_crcs)
1335{
1336 if (has_crcs) {
1337 amagic += strcspn(amagic, " ");
1338 bmagic += strcspn(bmagic, " ");
1339 }
1340 return strcmp(amagic, bmagic) == 0;
1341}
1342#else
1343static inline int check_version(Elf_Shdr *sechdrs,
1344 unsigned int versindex,
1345 const char *symname,
1346 struct module *mod,
1347 const unsigned long *crc,
1348 const struct module *crc_owner)
1349{
1350 return 1;
1351}
1352
1353static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1354 unsigned int versindex,
1355 struct module *mod)
1356{
1357 return 1;
1358}
1359
1360static inline int same_magic(const char *amagic, const char *bmagic,
1361 bool has_crcs)
1362{
1363 return strcmp(amagic, bmagic) == 0;
1364}
1365#endif /* CONFIG_MODVERSIONS */
1366
1367/* Resolve a symbol for this module. I.e. if we find one, record usage. */
1368static const struct kernel_symbol *resolve_symbol(struct module *mod,
1369 const struct load_info *info,
1370 const char *name,
1371 char ownername[])
1372{
1373 struct module *owner;
1374 const struct kernel_symbol *sym;
1375 const unsigned long *crc;
1376 int err;
1377
1378 /*
1379 * The module_mutex should not be a heavily contended lock;
1380 * if we get the occasional sleep here, we'll go an extra iteration
1381 * in the wait_event_interruptible(), which is harmless.
1382 */
1383 sched_annotate_sleep();
1384 mutex_lock(&module_mutex);
1385 sym = find_symbol(name, &owner, &crc,
1386 !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
1387 if (!sym)
1388 goto unlock;
1389
1390 if (!check_version(info->sechdrs, info->index.vers, name, mod, crc,
1391 owner)) {
1392 sym = ERR_PTR(-EINVAL);
1393 goto getname;
1394 }
1395
1396 err = ref_module(mod, owner);
1397 if (err) {
1398 sym = ERR_PTR(err);
1399 goto getname;
1400 }
1401
1402getname:
1403 /* We must make copy under the lock if we failed to get ref. */
1404 strncpy(ownername, module_name(owner), MODULE_NAME_LEN);
1405unlock:
1406 mutex_unlock(&module_mutex);
1407 return sym;
1408}
1409
1410static const struct kernel_symbol *
1411resolve_symbol_wait(struct module *mod,
1412 const struct load_info *info,
1413 const char *name)
1414{
1415 const struct kernel_symbol *ksym;
1416 char owner[MODULE_NAME_LEN];
1417
1418 if (wait_event_interruptible_timeout(module_wq,
1419 !IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
1420 || PTR_ERR(ksym) != -EBUSY,
1421 30 * HZ) <= 0) {
1422 pr_warn("%s: gave up waiting for init of module %s.\n",
1423 mod->name, owner);
1424 }
1425 return ksym;
1426}
1427
1428/*
1429 * /sys/module/foo/sections stuff
1430 * J. Corbet <corbet@lwn.net>
1431 */
1432#ifdef CONFIG_SYSFS
1433
1434#ifdef CONFIG_KALLSYMS
1435static inline bool sect_empty(const Elf_Shdr *sect)
1436{
1437 return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
1438}
1439
1440struct module_sect_attr {
1441 struct module_attribute mattr;
1442 char *name;
1443 unsigned long address;
1444};
1445
1446struct module_sect_attrs {
1447 struct attribute_group grp;
1448 unsigned int nsections;
1449 struct module_sect_attr attrs[0];
1450};
1451
1452static ssize_t module_sect_show(struct module_attribute *mattr,
1453 struct module_kobject *mk, char *buf)
1454{
1455 struct module_sect_attr *sattr =
1456 container_of(mattr, struct module_sect_attr, mattr);
1457 return sprintf(buf, "0x%pK\n", (void *)sattr->address);
1458}
1459
1460static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
1461{
1462 unsigned int section;
1463
1464 for (section = 0; section < sect_attrs->nsections; section++)
1465 kfree(sect_attrs->attrs[section].name);
1466 kfree(sect_attrs);
1467}
1468
1469static void add_sect_attrs(struct module *mod, const struct load_info *info)
1470{
1471 unsigned int nloaded = 0, i, size[2];
1472 struct module_sect_attrs *sect_attrs;
1473 struct module_sect_attr *sattr;
1474 struct attribute **gattr;
1475
1476 /* Count loaded sections and allocate structures */
1477 for (i = 0; i < info->hdr->e_shnum; i++)
1478 if (!sect_empty(&info->sechdrs[i]))
1479 nloaded++;
1480 size[0] = ALIGN(sizeof(*sect_attrs)
1481 + nloaded * sizeof(sect_attrs->attrs[0]),
1482 sizeof(sect_attrs->grp.attrs[0]));
1483 size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]);
1484 sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
1485 if (sect_attrs == NULL)
1486 return;
1487
1488 /* Setup section attributes. */
1489 sect_attrs->grp.name = "sections";
1490 sect_attrs->grp.attrs = (void *)sect_attrs + size[0];
1491
1492 sect_attrs->nsections = 0;
1493 sattr = §_attrs->attrs[0];
1494 gattr = §_attrs->grp.attrs[0];
1495 for (i = 0; i < info->hdr->e_shnum; i++) {
1496 Elf_Shdr *sec = &info->sechdrs[i];
1497 if (sect_empty(sec))
1498 continue;
1499 sattr->address = sec->sh_addr;
1500 sattr->name = kstrdup(info->secstrings + sec->sh_name,
1501 GFP_KERNEL);
1502 if (sattr->name == NULL)
1503 goto out;
1504 sect_attrs->nsections++;
1505 sysfs_attr_init(&sattr->mattr.attr);
1506 sattr->mattr.show = module_sect_show;
1507 sattr->mattr.store = NULL;
1508 sattr->mattr.attr.name = sattr->name;
1509 sattr->mattr.attr.mode = S_IRUGO;
1510 *(gattr++) = &(sattr++)->mattr.attr;
1511 }
1512 *gattr = NULL;
1513
1514 if (sysfs_create_group(&mod->mkobj.kobj, §_attrs->grp))
1515 goto out;
1516
1517 mod->sect_attrs = sect_attrs;
1518 return;
1519 out:
1520 free_sect_attrs(sect_attrs);
1521}
1522
1523static void remove_sect_attrs(struct module *mod)
1524{
1525 if (mod->sect_attrs) {
1526 sysfs_remove_group(&mod->mkobj.kobj,
1527 &mod->sect_attrs->grp);
1528 /* We are positive that no one is using any sect attrs
1529 * at this point. Deallocate immediately. */
1530 free_sect_attrs(mod->sect_attrs);
1531 mod->sect_attrs = NULL;
1532 }
1533}
1534
1535/*
1536 * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
1537 */
1538
1539struct module_notes_attrs {
1540 struct kobject *dir;
1541 unsigned int notes;
1542 struct bin_attribute attrs[0];
1543};
1544
1545static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
1546 struct bin_attribute *bin_attr,
1547 char *buf, loff_t pos, size_t count)
1548{
1549 /*
1550 * The caller checked the pos and count against our size.
1551 */
1552 memcpy(buf, bin_attr->private + pos, count);
1553 return count;
1554}
1555
1556static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
1557 unsigned int i)
1558{
1559 if (notes_attrs->dir) {
1560 while (i-- > 0)
1561 sysfs_remove_bin_file(notes_attrs->dir,
1562 ¬es_attrs->attrs[i]);
1563 kobject_put(notes_attrs->dir);
1564 }
1565 kfree(notes_attrs);
1566}
1567
1568static void add_notes_attrs(struct module *mod, const struct load_info *info)
1569{
1570 unsigned int notes, loaded, i;
1571 struct module_notes_attrs *notes_attrs;
1572 struct bin_attribute *nattr;
1573
1574 /* failed to create section attributes, so can't create notes */
1575 if (!mod->sect_attrs)
1576 return;
1577
1578 /* Count notes sections and allocate structures. */
1579 notes = 0;
1580 for (i = 0; i < info->hdr->e_shnum; i++)
1581 if (!sect_empty(&info->sechdrs[i]) &&
1582 (info->sechdrs[i].sh_type == SHT_NOTE))
1583 ++notes;
1584
1585 if (notes == 0)
1586 return;
1587
1588 notes_attrs = kzalloc(sizeof(*notes_attrs)
1589 + notes * sizeof(notes_attrs->attrs[0]),
1590 GFP_KERNEL);
1591 if (notes_attrs == NULL)
1592 return;
1593
1594 notes_attrs->notes = notes;
1595 nattr = ¬es_attrs->attrs[0];
1596 for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
1597 if (sect_empty(&info->sechdrs[i]))
1598 continue;
1599 if (info->sechdrs[i].sh_type == SHT_NOTE) {
1600 sysfs_bin_attr_init(nattr);
1601 nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
1602 nattr->attr.mode = S_IRUGO;
1603 nattr->size = info->sechdrs[i].sh_size;
1604 nattr->private = (void *) info->sechdrs[i].sh_addr;
1605 nattr->read = module_notes_read;
1606 ++nattr;
1607 }
1608 ++loaded;
1609 }
1610
1611 notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
1612 if (!notes_attrs->dir)
1613 goto out;
1614
1615 for (i = 0; i < notes; ++i)
1616 if (sysfs_create_bin_file(notes_attrs->dir,
1617 ¬es_attrs->attrs[i]))
1618 goto out;
1619
1620 mod->notes_attrs = notes_attrs;
1621 return;
1622
1623 out:
1624 free_notes_attrs(notes_attrs, i);
1625}
1626
1627static void remove_notes_attrs(struct module *mod)
1628{
1629 if (mod->notes_attrs)
1630 free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
1631}
1632
1633#else
1634
1635static inline void add_sect_attrs(struct module *mod,
1636 const struct load_info *info)
1637{
1638}
1639
1640static inline void remove_sect_attrs(struct module *mod)
1641{
1642}
1643
1644static inline void add_notes_attrs(struct module *mod,
1645 const struct load_info *info)
1646{
1647}
1648
1649static inline void remove_notes_attrs(struct module *mod)
1650{
1651}
1652#endif /* CONFIG_KALLSYMS */
1653
1654static void add_usage_links(struct module *mod)
1655{
1656#ifdef CONFIG_MODULE_UNLOAD
1657 struct module_use *use;
1658 int nowarn;
1659
1660 mutex_lock(&module_mutex);
1661 list_for_each_entry(use, &mod->target_list, target_list) {
1662 nowarn = sysfs_create_link(use->target->holders_dir,
1663 &mod->mkobj.kobj, mod->name);
1664 }
1665 mutex_unlock(&module_mutex);
1666#endif
1667}
1668
1669static void del_usage_links(struct module *mod)
1670{
1671#ifdef CONFIG_MODULE_UNLOAD
1672 struct module_use *use;
1673
1674 mutex_lock(&module_mutex);
1675 list_for_each_entry(use, &mod->target_list, target_list)
1676 sysfs_remove_link(use->target->holders_dir, mod->name);
1677 mutex_unlock(&module_mutex);
1678#endif
1679}
1680
1681static int module_add_modinfo_attrs(struct module *mod)
1682{
1683 struct module_attribute *attr;
1684 struct module_attribute *temp_attr;
1685 int error = 0;
1686 int i;
1687
1688 mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
1689 (ARRAY_SIZE(modinfo_attrs) + 1)),
1690 GFP_KERNEL);
1691 if (!mod->modinfo_attrs)
1692 return -ENOMEM;
1693
1694 temp_attr = mod->modinfo_attrs;
1695 for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
1696 if (!attr->test ||
1697 (attr->test && attr->test(mod))) {
1698 memcpy(temp_attr, attr, sizeof(*temp_attr));
1699 sysfs_attr_init(&temp_attr->attr);
1700 error = sysfs_create_file(&mod->mkobj.kobj,
1701 &temp_attr->attr);
1702 ++temp_attr;
1703 }
1704 }
1705 return error;
1706}
1707
1708static void module_remove_modinfo_attrs(struct module *mod)
1709{
1710 struct module_attribute *attr;
1711 int i;
1712
1713 for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
1714 /* pick a field to test for end of list */
1715 if (!attr->attr.name)
1716 break;
1717 sysfs_remove_file(&mod->mkobj.kobj, &attr->attr);
1718 if (attr->free)
1719 attr->free(mod);
1720 }
1721 kfree(mod->modinfo_attrs);
1722}
1723
1724static void mod_kobject_put(struct module *mod)
1725{
1726 DECLARE_COMPLETION_ONSTACK(c);
1727 mod->mkobj.kobj_completion = &c;
1728 kobject_put(&mod->mkobj.kobj);
1729 wait_for_completion(&c);
1730}
1731
1732static int mod_sysfs_init(struct module *mod)
1733{
1734 int err;
1735 struct kobject *kobj;
1736
1737 if (!module_sysfs_initialized) {
1738 pr_err("%s: module sysfs not initialized\n", mod->name);
1739 err = -EINVAL;
1740 goto out;
1741 }
1742
1743 kobj = kset_find_obj(module_kset, mod->name);
1744 if (kobj) {
1745 pr_err("%s: module is already loaded\n", mod->name);
1746 kobject_put(kobj);
1747 err = -EINVAL;
1748 goto out;
1749 }
1750
1751 mod->mkobj.mod = mod;
1752
1753 memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
1754 mod->mkobj.kobj.kset = module_kset;
1755 err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
1756 "%s", mod->name);
1757 if (err)
1758 mod_kobject_put(mod);
1759
1760 /* delay uevent until full sysfs population */
1761out:
1762 return err;
1763}
1764
1765static int mod_sysfs_setup(struct module *mod,
1766 const struct load_info *info,
1767 struct kernel_param *kparam,
1768 unsigned int num_params)
1769{
1770 int err;
1771
1772 err = mod_sysfs_init(mod);
1773 if (err)
1774 goto out;
1775
1776 mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1777 if (!mod->holders_dir) {
1778 err = -ENOMEM;
1779 goto out_unreg;
1780 }
1781
1782 err = module_param_sysfs_setup(mod, kparam, num_params);
1783 if (err)
1784 goto out_unreg_holders;
1785
1786 err = module_add_modinfo_attrs(mod);
1787 if (err)
1788 goto out_unreg_param;
1789
1790 add_usage_links(mod);
1791 add_sect_attrs(mod, info);
1792 add_notes_attrs(mod, info);
1793
1794 kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
1795 return 0;
1796
1797out_unreg_param:
1798 module_param_sysfs_remove(mod);
1799out_unreg_holders:
1800 kobject_put(mod->holders_dir);
1801out_unreg:
1802 mod_kobject_put(mod);
1803out:
1804 return err;
1805}
1806
1807static void mod_sysfs_fini(struct module *mod)
1808{
1809 remove_notes_attrs(mod);
1810 remove_sect_attrs(mod);
1811 mod_kobject_put(mod);
1812}
1813
1814static void init_param_lock(struct module *mod)
1815{
1816 mutex_init(&mod->param_lock);
1817}
1818#else /* !CONFIG_SYSFS */
1819
1820static int mod_sysfs_setup(struct module *mod,
1821 const struct load_info *info,
1822 struct kernel_param *kparam,
1823 unsigned int num_params)
1824{
1825 return 0;
1826}
1827
1828static void mod_sysfs_fini(struct module *mod)
1829{
1830}
1831
1832static void module_remove_modinfo_attrs(struct module *mod)
1833{
1834}
1835
1836static void del_usage_links(struct module *mod)
1837{
1838}
1839
1840static void init_param_lock(struct module *mod)
1841{
1842}
1843#endif /* CONFIG_SYSFS */
1844
1845static void mod_sysfs_teardown(struct module *mod)
1846{
1847 del_usage_links(mod);
1848 module_remove_modinfo_attrs(mod);
1849 module_param_sysfs_remove(mod);
1850 kobject_put(mod->mkobj.drivers_dir);
1851 kobject_put(mod->holders_dir);
1852 mod_sysfs_fini(mod);
1853}
1854
1855#ifdef CONFIG_DEBUG_SET_MODULE_RONX
1856/*
1857 * LKM RO/NX protection: protect module's text/ro-data
1858 * from modification and any data from execution.
1859 *
1860 * General layout of module is:
1861 * [text] [read-only-data] [writable data]
1862 * text_size -----^ ^ ^
1863 * ro_size ------------------------| |
1864 * size -------------------------------------------|
1865 *
1866 * These values are always page-aligned (as is base)
1867 */
1868static void frob_text(const struct module_layout *layout,
1869 int (*set_memory)(unsigned long start, int num_pages))
1870{
1871 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1872 BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
1873 set_memory((unsigned long)layout->base,
1874 layout->text_size >> PAGE_SHIFT);
1875}
1876
1877static void frob_rodata(const struct module_layout *layout,
1878 int (*set_memory)(unsigned long start, int num_pages))
1879{
1880 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1881 BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
1882 BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
1883 set_memory((unsigned long)layout->base + layout->text_size,
1884 (layout->ro_size - layout->text_size) >> PAGE_SHIFT);
1885}
1886
1887static void frob_writable_data(const struct module_layout *layout,
1888 int (*set_memory)(unsigned long start, int num_pages))
1889{
1890 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1891 BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
1892 BUG_ON((unsigned long)layout->size & (PAGE_SIZE-1));
1893 set_memory((unsigned long)layout->base + layout->ro_size,
1894 (layout->size - layout->ro_size) >> PAGE_SHIFT);
1895}
1896
1897/* livepatching wants to disable read-only so it can frob module. */
1898void module_disable_ro(const struct module *mod)
1899{
1900 frob_text(&mod->core_layout, set_memory_rw);
1901 frob_rodata(&mod->core_layout, set_memory_rw);
1902 frob_text(&mod->init_layout, set_memory_rw);
1903 frob_rodata(&mod->init_layout, set_memory_rw);
1904}
1905
1906void module_enable_ro(const struct module *mod)
1907{
1908 frob_text(&mod->core_layout, set_memory_ro);
1909 frob_rodata(&mod->core_layout, set_memory_ro);
1910 frob_text(&mod->init_layout, set_memory_ro);
1911 frob_rodata(&mod->init_layout, set_memory_ro);
1912}
1913
1914static void module_enable_nx(const struct module *mod)
1915{
1916 frob_rodata(&mod->core_layout, set_memory_nx);
1917 frob_writable_data(&mod->core_layout, set_memory_nx);
1918 frob_rodata(&mod->init_layout, set_memory_nx);
1919 frob_writable_data(&mod->init_layout, set_memory_nx);
1920}
1921
1922static void module_disable_nx(const struct module *mod)
1923{
1924 frob_rodata(&mod->core_layout, set_memory_x);
1925 frob_writable_data(&mod->core_layout, set_memory_x);
1926 frob_rodata(&mod->init_layout, set_memory_x);
1927 frob_writable_data(&mod->init_layout, set_memory_x);
1928}
1929
1930/* Iterate through all modules and set each module's text as RW */
1931void set_all_modules_text_rw(void)
1932{
1933 struct module *mod;
1934
1935 mutex_lock(&module_mutex);
1936 list_for_each_entry_rcu(mod, &modules, list) {
1937 if (mod->state == MODULE_STATE_UNFORMED)
1938 continue;
1939
1940 frob_text(&mod->core_layout, set_memory_rw);
1941 frob_text(&mod->init_layout, set_memory_rw);
1942 }
1943 mutex_unlock(&module_mutex);
1944}
1945
1946/* Iterate through all modules and set each module's text as RO */
1947void set_all_modules_text_ro(void)
1948{
1949 struct module *mod;
1950
1951 mutex_lock(&module_mutex);
1952 list_for_each_entry_rcu(mod, &modules, list) {
1953 if (mod->state == MODULE_STATE_UNFORMED)
1954 continue;
1955
1956 frob_text(&mod->core_layout, set_memory_ro);
1957 frob_text(&mod->init_layout, set_memory_ro);
1958 }
1959 mutex_unlock(&module_mutex);
1960}
1961
1962static void disable_ro_nx(const struct module_layout *layout)
1963{
1964 frob_text(layout, set_memory_rw);
1965 frob_rodata(layout, set_memory_rw);
1966 frob_rodata(layout, set_memory_x);
1967 frob_writable_data(layout, set_memory_x);
1968}
1969
1970#else
1971static void disable_ro_nx(const struct module_layout *layout) { }
1972static void module_enable_nx(const struct module *mod) { }
1973static void module_disable_nx(const struct module *mod) { }
1974#endif
1975
1976void __weak module_memfree(void *module_region)
1977{
1978 vfree(module_region);
1979}
1980
1981void __weak module_arch_cleanup(struct module *mod)
1982{
1983}
1984
1985void __weak module_arch_freeing_init(struct module *mod)
1986{
1987}
1988
1989/* Free a module, remove from lists, etc. */
1990static void free_module(struct module *mod)
1991{
1992 trace_module_free(mod);
1993
1994 mod_sysfs_teardown(mod);
1995
1996 /* We leave it in list to prevent duplicate loads, but make sure
1997 * that noone uses it while it's being deconstructed. */
1998 mutex_lock(&module_mutex);
1999 mod->state = MODULE_STATE_UNFORMED;
2000 mutex_unlock(&module_mutex);
2001
2002 /* Remove dynamic debug info */
2003 ddebug_remove_module(mod->name);
2004
2005 /* Arch-specific cleanup. */
2006 module_arch_cleanup(mod);
2007
2008 /* Module unload stuff */
2009 module_unload_free(mod);
2010
2011 /* Free any allocated parameters. */
2012 destroy_params(mod->kp, mod->num_kp);
2013
2014 /* Now we can delete it from the lists */
2015 mutex_lock(&module_mutex);
2016 /* Unlink carefully: kallsyms could be walking list. */
2017 list_del_rcu(&mod->list);
2018 mod_tree_remove(mod);
2019 /* Remove this module from bug list, this uses list_del_rcu */
2020 module_bug_cleanup(mod);
2021 /* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */
2022 synchronize_sched();
2023 mutex_unlock(&module_mutex);
2024
2025 /* This may be empty, but that's OK */
2026 disable_ro_nx(&mod->init_layout);
2027 module_arch_freeing_init(mod);
2028 module_memfree(mod->init_layout.base);
2029 kfree(mod->args);
2030 percpu_modfree(mod);
2031
2032 /* Free lock-classes; relies on the preceding sync_rcu(). */
2033 lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
2034
2035 /* Finally, free the core (containing the module structure) */
2036 disable_ro_nx(&mod->core_layout);
2037 module_memfree(mod->core_layout.base);
2038
2039#ifdef CONFIG_MPU
2040 update_protections(current->mm);
2041#endif
2042}
2043
2044void *__symbol_get(const char *symbol)
2045{
2046 struct module *owner;
2047 const struct kernel_symbol *sym;
2048
2049 preempt_disable();
2050 sym = find_symbol(symbol, &owner, NULL, true, true);
2051 if (sym && strong_try_module_get(owner))
2052 sym = NULL;
2053 preempt_enable();
2054
2055 return sym ? (void *)sym->value : NULL;
2056}
2057EXPORT_SYMBOL_GPL(__symbol_get);
2058
2059/*
2060 * Ensure that an exported symbol [global namespace] does not already exist
2061 * in the kernel or in some other module's exported symbol table.
2062 *
2063 * You must hold the module_mutex.
2064 */
2065static int verify_export_symbols(struct module *mod)
2066{
2067 unsigned int i;
2068 struct module *owner;
2069 const struct kernel_symbol *s;
2070 struct {
2071 const struct kernel_symbol *sym;
2072 unsigned int num;
2073 } arr[] = {
2074 { mod->syms, mod->num_syms },
2075 { mod->gpl_syms, mod->num_gpl_syms },
2076 { mod->gpl_future_syms, mod->num_gpl_future_syms },
2077#ifdef CONFIG_UNUSED_SYMBOLS
2078 { mod->unused_syms, mod->num_unused_syms },
2079 { mod->unused_gpl_syms, mod->num_unused_gpl_syms },
2080#endif
2081 };
2082
2083 for (i = 0; i < ARRAY_SIZE(arr); i++) {
2084 for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
2085 if (find_symbol(s->name, &owner, NULL, true, false)) {
2086 pr_err("%s: exports duplicate symbol %s"
2087 " (owned by %s)\n",
2088 mod->name, s->name, module_name(owner));
2089 return -ENOEXEC;
2090 }
2091 }
2092 }
2093 return 0;
2094}
2095
2096/* Change all symbols so that st_value encodes the pointer directly. */
2097static int simplify_symbols(struct module *mod, const struct load_info *info)
2098{
2099 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2100 Elf_Sym *sym = (void *)symsec->sh_addr;
2101 unsigned long secbase;
2102 unsigned int i;
2103 int ret = 0;
2104 const struct kernel_symbol *ksym;
2105
2106 for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
2107 const char *name = info->strtab + sym[i].st_name;
2108
2109 switch (sym[i].st_shndx) {
2110 case SHN_COMMON:
2111 /* Ignore common symbols */
2112 if (!strncmp(name, "__gnu_lto", 9))
2113 break;
2114
2115 /* We compiled with -fno-common. These are not
2116 supposed to happen. */
2117 pr_debug("Common symbol: %s\n", name);
2118 pr_warn("%s: please compile with -fno-common\n",
2119 mod->name);
2120 ret = -ENOEXEC;
2121 break;
2122
2123 case SHN_ABS:
2124 /* Don't need to do anything */
2125 pr_debug("Absolute symbol: 0x%08lx\n",
2126 (long)sym[i].st_value);
2127 break;
2128
2129 case SHN_UNDEF:
2130 ksym = resolve_symbol_wait(mod, info, name);
2131 /* Ok if resolved. */
2132 if (ksym && !IS_ERR(ksym)) {
2133 sym[i].st_value = ksym->value;
2134 break;
2135 }
2136
2137 /* Ok if weak. */
2138 if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
2139 break;
2140
2141 pr_warn("%s: Unknown symbol %s (err %li)\n",
2142 mod->name, name, PTR_ERR(ksym));
2143 ret = PTR_ERR(ksym) ?: -ENOENT;
2144 break;
2145
2146 default:
2147 /* Divert to percpu allocation if a percpu var. */
2148 if (sym[i].st_shndx == info->index.pcpu)
2149 secbase = (unsigned long)mod_percpu(mod);
2150 else
2151 secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
2152 sym[i].st_value += secbase;
2153 break;
2154 }
2155 }
2156
2157 return ret;
2158}
2159
2160static int apply_relocations(struct module *mod, const struct load_info *info)
2161{
2162 unsigned int i;
2163 int err = 0;
2164
2165 /* Now do relocations. */
2166 for (i = 1; i < info->hdr->e_shnum; i++) {
2167 unsigned int infosec = info->sechdrs[i].sh_info;
2168
2169 /* Not a valid relocation section? */
2170 if (infosec >= info->hdr->e_shnum)
2171 continue;
2172
2173 /* Don't bother with non-allocated sections */
2174 if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
2175 continue;
2176
2177 if (info->sechdrs[i].sh_type == SHT_REL)
2178 err = apply_relocate(info->sechdrs, info->strtab,
2179 info->index.sym, i, mod);
2180 else if (info->sechdrs[i].sh_type == SHT_RELA)
2181 err = apply_relocate_add(info->sechdrs, info->strtab,
2182 info->index.sym, i, mod);
2183 if (err < 0)
2184 break;
2185 }
2186 return err;
2187}
2188
2189/* Additional bytes needed by arch in front of individual sections */
2190unsigned int __weak arch_mod_section_prepend(struct module *mod,
2191 unsigned int section)
2192{
2193 /* default implementation just returns zero */
2194 return 0;
2195}
2196
2197/* Update size with this section: return offset. */
2198static long get_offset(struct module *mod, unsigned int *size,
2199 Elf_Shdr *sechdr, unsigned int section)
2200{
2201 long ret;
2202
2203 *size += arch_mod_section_prepend(mod, section);
2204 ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
2205 *size = ret + sechdr->sh_size;
2206 return ret;
2207}
2208
2209/* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
2210 might -- code, read-only data, read-write data, small data. Tally
2211 sizes, and place the offsets into sh_entsize fields: high bit means it
2212 belongs in init. */
2213static void layout_sections(struct module *mod, struct load_info *info)
2214{
2215 static unsigned long const masks[][2] = {
2216 /* NOTE: all executable code must be the first section
2217 * in this array; otherwise modify the text_size
2218 * finder in the two loops below */
2219 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
2220 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
2221 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
2222 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
2223 };
2224 unsigned int m, i;
2225
2226 for (i = 0; i < info->hdr->e_shnum; i++)
2227 info->sechdrs[i].sh_entsize = ~0UL;
2228
2229 pr_debug("Core section allocation order:\n");
2230 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2231 for (i = 0; i < info->hdr->e_shnum; ++i) {
2232 Elf_Shdr *s = &info->sechdrs[i];
2233 const char *sname = info->secstrings + s->sh_name;
2234
2235 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2236 || (s->sh_flags & masks[m][1])
2237 || s->sh_entsize != ~0UL
2238 || strstarts(sname, ".init"))
2239 continue;
2240 s->sh_entsize = get_offset(mod, &mod->core_layout.size, s, i);
2241 pr_debug("\t%s\n", sname);
2242 }
2243 switch (m) {
2244 case 0: /* executable */
2245 mod->core_layout.size = debug_align(mod->core_layout.size);
2246 mod->core_layout.text_size = mod->core_layout.size;
2247 break;
2248 case 1: /* RO: text and ro-data */
2249 mod->core_layout.size = debug_align(mod->core_layout.size);
2250 mod->core_layout.ro_size = mod->core_layout.size;
2251 break;
2252 case 3: /* whole core */
2253 mod->core_layout.size = debug_align(mod->core_layout.size);
2254 break;
2255 }
2256 }
2257
2258 pr_debug("Init section allocation order:\n");
2259 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2260 for (i = 0; i < info->hdr->e_shnum; ++i) {
2261 Elf_Shdr *s = &info->sechdrs[i];
2262 const char *sname = info->secstrings + s->sh_name;
2263
2264 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2265 || (s->sh_flags & masks[m][1])
2266 || s->sh_entsize != ~0UL
2267 || !strstarts(sname, ".init"))
2268 continue;
2269 s->sh_entsize = (get_offset(mod, &mod->init_layout.size, s, i)
2270 | INIT_OFFSET_MASK);
2271 pr_debug("\t%s\n", sname);
2272 }
2273 switch (m) {
2274 case 0: /* executable */
2275 mod->init_layout.size = debug_align(mod->init_layout.size);
2276 mod->init_layout.text_size = mod->init_layout.size;
2277 break;
2278 case 1: /* RO: text and ro-data */
2279 mod->init_layout.size = debug_align(mod->init_layout.size);
2280 mod->init_layout.ro_size = mod->init_layout.size;
2281 break;
2282 case 3: /* whole init */
2283 mod->init_layout.size = debug_align(mod->init_layout.size);
2284 break;
2285 }
2286 }
2287}
2288
2289static void set_license(struct module *mod, const char *license)
2290{
2291 if (!license)
2292 license = "unspecified";
2293
2294 if (!license_is_gpl_compatible(license)) {
2295 if (!test_taint(TAINT_PROPRIETARY_MODULE))
2296 pr_warn("%s: module license '%s' taints kernel.\n",
2297 mod->name, license);
2298 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2299 LOCKDEP_NOW_UNRELIABLE);
2300 }
2301}
2302
2303/* Parse tag=value strings from .modinfo section */
2304static char *next_string(char *string, unsigned long *secsize)
2305{
2306 /* Skip non-zero chars */
2307 while (string[0]) {
2308 string++;
2309 if ((*secsize)-- <= 1)
2310 return NULL;
2311 }
2312
2313 /* Skip any zero padding. */
2314 while (!string[0]) {
2315 string++;
2316 if ((*secsize)-- <= 1)
2317 return NULL;
2318 }
2319 return string;
2320}
2321
2322static char *get_modinfo(struct load_info *info, const char *tag)
2323{
2324 char *p;
2325 unsigned int taglen = strlen(tag);
2326 Elf_Shdr *infosec = &info->sechdrs[info->index.info];
2327 unsigned long size = infosec->sh_size;
2328
2329 for (p = (char *)infosec->sh_addr; p; p = next_string(p, &size)) {
2330 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
2331 return p + taglen + 1;
2332 }
2333 return NULL;
2334}
2335
2336static void setup_modinfo(struct module *mod, struct load_info *info)
2337{
2338 struct module_attribute *attr;
2339 int i;
2340
2341 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2342 if (attr->setup)
2343 attr->setup(mod, get_modinfo(info, attr->attr.name));
2344 }
2345}
2346
2347static void free_modinfo(struct module *mod)
2348{
2349 struct module_attribute *attr;
2350 int i;
2351
2352 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2353 if (attr->free)
2354 attr->free(mod);
2355 }
2356}
2357
2358#ifdef CONFIG_KALLSYMS
2359
2360/* lookup symbol in given range of kernel_symbols */
2361static const struct kernel_symbol *lookup_symbol(const char *name,
2362 const struct kernel_symbol *start,
2363 const struct kernel_symbol *stop)
2364{
2365 return bsearch(name, start, stop - start,
2366 sizeof(struct kernel_symbol), cmp_name);
2367}
2368
2369static int is_exported(const char *name, unsigned long value,
2370 const struct module *mod)
2371{
2372 const struct kernel_symbol *ks;
2373 if (!mod)
2374 ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
2375 else
2376 ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
2377 return ks != NULL && ks->value == value;
2378}
2379
2380/* As per nm */
2381static char elf_type(const Elf_Sym *sym, const struct load_info *info)
2382{
2383 const Elf_Shdr *sechdrs = info->sechdrs;
2384
2385 if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
2386 if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
2387 return 'v';
2388 else
2389 return 'w';
2390 }
2391 if (sym->st_shndx == SHN_UNDEF)
2392 return 'U';
2393 if (sym->st_shndx == SHN_ABS || sym->st_shndx == info->index.pcpu)
2394 return 'a';
2395 if (sym->st_shndx >= SHN_LORESERVE)
2396 return '?';
2397 if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
2398 return 't';
2399 if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
2400 && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
2401 if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
2402 return 'r';
2403 else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2404 return 'g';
2405 else
2406 return 'd';
2407 }
2408 if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
2409 if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2410 return 's';
2411 else
2412 return 'b';
2413 }
2414 if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
2415 ".debug")) {
2416 return 'n';
2417 }
2418 return '?';
2419}
2420
2421static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
2422 unsigned int shnum, unsigned int pcpundx)
2423{
2424 const Elf_Shdr *sec;
2425
2426 if (src->st_shndx == SHN_UNDEF
2427 || src->st_shndx >= shnum
2428 || !src->st_name)
2429 return false;
2430
2431#ifdef CONFIG_KALLSYMS_ALL
2432 if (src->st_shndx == pcpundx)
2433 return true;
2434#endif
2435
2436 sec = sechdrs + src->st_shndx;
2437 if (!(sec->sh_flags & SHF_ALLOC)
2438#ifndef CONFIG_KALLSYMS_ALL
2439 || !(sec->sh_flags & SHF_EXECINSTR)
2440#endif
2441 || (sec->sh_entsize & INIT_OFFSET_MASK))
2442 return false;
2443
2444 return true;
2445}
2446
2447/*
2448 * We only allocate and copy the strings needed by the parts of symtab
2449 * we keep. This is simple, but has the effect of making multiple
2450 * copies of duplicates. We could be more sophisticated, see
2451 * linux-kernel thread starting with
2452 * <73defb5e4bca04a6431392cc341112b1@localhost>.
2453 */
2454static void layout_symtab(struct module *mod, struct load_info *info)
2455{
2456 Elf_Shdr *symsect = info->sechdrs + info->index.sym;
2457 Elf_Shdr *strsect = info->sechdrs + info->index.str;
2458 const Elf_Sym *src;
2459 unsigned int i, nsrc, ndst, strtab_size = 0;
2460
2461 /* Put symbol section at end of init part of module. */
2462 symsect->sh_flags |= SHF_ALLOC;
2463 symsect->sh_entsize = get_offset(mod, &mod->init_layout.size, symsect,
2464 info->index.sym) | INIT_OFFSET_MASK;
2465 pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
2466
2467 src = (void *)info->hdr + symsect->sh_offset;
2468 nsrc = symsect->sh_size / sizeof(*src);
2469
2470 /* Compute total space required for the core symbols' strtab. */
2471 for (ndst = i = 0; i < nsrc; i++) {
2472 if (i == 0 ||
2473 is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
2474 info->index.pcpu)) {
2475 strtab_size += strlen(&info->strtab[src[i].st_name])+1;
2476 ndst++;
2477 }
2478 }
2479
2480 /* Append room for core symbols at end of core part. */
2481 info->symoffs = ALIGN(mod->core_layout.size, symsect->sh_addralign ?: 1);
2482 info->stroffs = mod->core_layout.size = info->symoffs + ndst * sizeof(Elf_Sym);
2483 mod->core_layout.size += strtab_size;
2484 mod->core_layout.size = debug_align(mod->core_layout.size);
2485
2486 /* Put string table section at end of init part of module. */
2487 strsect->sh_flags |= SHF_ALLOC;
2488 strsect->sh_entsize = get_offset(mod, &mod->init_layout.size, strsect,
2489 info->index.str) | INIT_OFFSET_MASK;
2490 pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
2491
2492 /* We'll tack temporary mod_kallsyms on the end. */
2493 mod->init_layout.size = ALIGN(mod->init_layout.size,
2494 __alignof__(struct mod_kallsyms));
2495 info->mod_kallsyms_init_off = mod->init_layout.size;
2496 mod->init_layout.size += sizeof(struct mod_kallsyms);
2497 mod->init_layout.size = debug_align(mod->init_layout.size);
2498}
2499
2500/*
2501 * We use the full symtab and strtab which layout_symtab arranged to
2502 * be appended to the init section. Later we switch to the cut-down
2503 * core-only ones.
2504 */
2505static void add_kallsyms(struct module *mod, const struct load_info *info)
2506{
2507 unsigned int i, ndst;
2508 const Elf_Sym *src;
2509 Elf_Sym *dst;
2510 char *s;
2511 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2512
2513 /* Set up to point into init section. */
2514 mod->kallsyms = mod->init_layout.base + info->mod_kallsyms_init_off;
2515
2516 mod->kallsyms->symtab = (void *)symsec->sh_addr;
2517 mod->kallsyms->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
2518 /* Make sure we get permanent strtab: don't use info->strtab. */
2519 mod->kallsyms->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
2520
2521 /* Set types up while we still have access to sections. */
2522 for (i = 0; i < mod->kallsyms->num_symtab; i++)
2523 mod->kallsyms->symtab[i].st_info
2524 = elf_type(&mod->kallsyms->symtab[i], info);
2525
2526 /* Now populate the cut down core kallsyms for after init. */
2527 mod->core_kallsyms.symtab = dst = mod->core_layout.base + info->symoffs;
2528 mod->core_kallsyms.strtab = s = mod->core_layout.base + info->stroffs;
2529 src = mod->kallsyms->symtab;
2530 for (ndst = i = 0; i < mod->kallsyms->num_symtab; i++) {
2531 if (i == 0 ||
2532 is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
2533 info->index.pcpu)) {
2534 dst[ndst] = src[i];
2535 dst[ndst++].st_name = s - mod->core_kallsyms.strtab;
2536 s += strlcpy(s, &mod->kallsyms->strtab[src[i].st_name],
2537 KSYM_NAME_LEN) + 1;
2538 }
2539 }
2540 mod->core_kallsyms.num_symtab = ndst;
2541}
2542#else
2543static inline void layout_symtab(struct module *mod, struct load_info *info)
2544{
2545}
2546
2547static void add_kallsyms(struct module *mod, const struct load_info *info)
2548{
2549}
2550#endif /* CONFIG_KALLSYMS */
2551
2552static void dynamic_debug_setup(struct _ddebug *debug, unsigned int num)
2553{
2554 if (!debug)
2555 return;
2556#ifdef CONFIG_DYNAMIC_DEBUG
2557 if (ddebug_add_module(debug, num, debug->modname))
2558 pr_err("dynamic debug error adding module: %s\n",
2559 debug->modname);
2560#endif
2561}
2562
2563static void dynamic_debug_remove(struct _ddebug *debug)
2564{
2565 if (debug)
2566 ddebug_remove_module(debug->modname);
2567}
2568
2569void * __weak module_alloc(unsigned long size)
2570{
2571 return vmalloc_exec(size);
2572}
2573
2574#ifdef CONFIG_DEBUG_KMEMLEAK
2575static void kmemleak_load_module(const struct module *mod,
2576 const struct load_info *info)
2577{
2578 unsigned int i;
2579
2580 /* only scan the sections containing data */
2581 kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
2582
2583 for (i = 1; i < info->hdr->e_shnum; i++) {
2584 /* Scan all writable sections that's not executable */
2585 if (!(info->sechdrs[i].sh_flags & SHF_ALLOC) ||
2586 !(info->sechdrs[i].sh_flags & SHF_WRITE) ||
2587 (info->sechdrs[i].sh_flags & SHF_EXECINSTR))
2588 continue;
2589
2590 kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
2591 info->sechdrs[i].sh_size, GFP_KERNEL);
2592 }
2593}
2594#else
2595static inline void kmemleak_load_module(const struct module *mod,
2596 const struct load_info *info)
2597{
2598}
2599#endif
2600
2601#ifdef CONFIG_MODULE_SIG
2602static int module_sig_check(struct load_info *info)
2603{
2604 int err = -ENOKEY;
2605 const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
2606 const void *mod = info->hdr;
2607
2608 if (info->len > markerlen &&
2609 memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
2610 /* We truncate the module to discard the signature */
2611 info->len -= markerlen;
2612 err = mod_verify_sig(mod, &info->len);
2613 }
2614
2615 if (!err) {
2616 info->sig_ok = true;
2617 return 0;
2618 }
2619
2620 /* Not having a signature is only an error if we're strict. */
2621 if (err == -ENOKEY && !sig_enforce)
2622 err = 0;
2623
2624 return err;
2625}
2626#else /* !CONFIG_MODULE_SIG */
2627static int module_sig_check(struct load_info *info)
2628{
2629 return 0;
2630}
2631#endif /* !CONFIG_MODULE_SIG */
2632
2633/* Sanity checks against invalid binaries, wrong arch, weird elf version. */
2634static int elf_header_check(struct load_info *info)
2635{
2636 if (info->len < sizeof(*(info->hdr)))
2637 return -ENOEXEC;
2638
2639 if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0
2640 || info->hdr->e_type != ET_REL
2641 || !elf_check_arch(info->hdr)
2642 || info->hdr->e_shentsize != sizeof(Elf_Shdr))
2643 return -ENOEXEC;
2644
2645 if (info->hdr->e_shoff >= info->len
2646 || (info->hdr->e_shnum * sizeof(Elf_Shdr) >
2647 info->len - info->hdr->e_shoff))
2648 return -ENOEXEC;
2649
2650 return 0;
2651}
2652
2653#define COPY_CHUNK_SIZE (16*PAGE_SIZE)
2654
2655static int copy_chunked_from_user(void *dst, const void __user *usrc, unsigned long len)
2656{
2657 do {
2658 unsigned long n = min(len, COPY_CHUNK_SIZE);
2659
2660 if (copy_from_user(dst, usrc, n) != 0)
2661 return -EFAULT;
2662 cond_resched();
2663 dst += n;
2664 usrc += n;
2665 len -= n;
2666 } while (len);
2667 return 0;
2668}
2669
2670/* Sets info->hdr and info->len. */
2671static int copy_module_from_user(const void __user *umod, unsigned long len,
2672 struct load_info *info)
2673{
2674 int err;
2675
2676 info->len = len;
2677 if (info->len < sizeof(*(info->hdr)))
2678 return -ENOEXEC;
2679
2680 err = security_kernel_read_file(NULL, READING_MODULE);
2681 if (err)
2682 return err;
2683
2684 /* Suck in entire file: we'll want most of it. */
2685 info->hdr = __vmalloc(info->len,
2686 GFP_KERNEL | __GFP_HIGHMEM | __GFP_NOWARN, PAGE_KERNEL);
2687 if (!info->hdr)
2688 return -ENOMEM;
2689
2690 if (copy_chunked_from_user(info->hdr, umod, info->len) != 0) {
2691 vfree(info->hdr);
2692 return -EFAULT;
2693 }
2694
2695 return 0;
2696}
2697
2698static void free_copy(struct load_info *info)
2699{
2700 vfree(info->hdr);
2701}
2702
2703static int rewrite_section_headers(struct load_info *info, int flags)
2704{
2705 unsigned int i;
2706
2707 /* This should always be true, but let's be sure. */
2708 info->sechdrs[0].sh_addr = 0;
2709
2710 for (i = 1; i < info->hdr->e_shnum; i++) {
2711 Elf_Shdr *shdr = &info->sechdrs[i];
2712 if (shdr->sh_type != SHT_NOBITS
2713 && info->len < shdr->sh_offset + shdr->sh_size) {
2714 pr_err("Module len %lu truncated\n", info->len);
2715 return -ENOEXEC;
2716 }
2717
2718 /* Mark all sections sh_addr with their address in the
2719 temporary image. */
2720 shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
2721
2722#ifndef CONFIG_MODULE_UNLOAD
2723 /* Don't load .exit sections */
2724 if (strstarts(info->secstrings+shdr->sh_name, ".exit"))
2725 shdr->sh_flags &= ~(unsigned long)SHF_ALLOC;
2726#endif
2727 }
2728
2729 /* Track but don't keep modinfo and version sections. */
2730 if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
2731 info->index.vers = 0; /* Pretend no __versions section! */
2732 else
2733 info->index.vers = find_sec(info, "__versions");
2734 info->index.info = find_sec(info, ".modinfo");
2735 info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
2736 info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
2737 return 0;
2738}
2739
2740/*
2741 * Set up our basic convenience variables (pointers to section headers,
2742 * search for module section index etc), and do some basic section
2743 * verification.
2744 *
2745 * Return the temporary module pointer (we'll replace it with the final
2746 * one when we move the module sections around).
2747 */
2748static struct module *setup_load_info(struct load_info *info, int flags)
2749{
2750 unsigned int i;
2751 int err;
2752 struct module *mod;
2753
2754 /* Set up the convenience variables */
2755 info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
2756 info->secstrings = (void *)info->hdr
2757 + info->sechdrs[info->hdr->e_shstrndx].sh_offset;
2758
2759 err = rewrite_section_headers(info, flags);
2760 if (err)
2761 return ERR_PTR(err);
2762
2763 /* Find internal symbols and strings. */
2764 for (i = 1; i < info->hdr->e_shnum; i++) {
2765 if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
2766 info->index.sym = i;
2767 info->index.str = info->sechdrs[i].sh_link;
2768 info->strtab = (char *)info->hdr
2769 + info->sechdrs[info->index.str].sh_offset;
2770 break;
2771 }
2772 }
2773
2774 info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
2775 if (!info->index.mod) {
2776 pr_warn("No module found in object\n");
2777 return ERR_PTR(-ENOEXEC);
2778 }
2779 /* This is temporary: point mod into copy of data. */
2780 mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2781
2782 if (info->index.sym == 0) {
2783 pr_warn("%s: module has no symbols (stripped?)\n", mod->name);
2784 return ERR_PTR(-ENOEXEC);
2785 }
2786
2787 info->index.pcpu = find_pcpusec(info);
2788
2789 /* Check module struct version now, before we try to use module. */
2790 if (!check_modstruct_version(info->sechdrs, info->index.vers, mod))
2791 return ERR_PTR(-ENOEXEC);
2792
2793 return mod;
2794}
2795
2796static int check_modinfo(struct module *mod, struct load_info *info, int flags)
2797{
2798 const char *modmagic = get_modinfo(info, "vermagic");
2799 int err;
2800
2801 if (flags & MODULE_INIT_IGNORE_VERMAGIC)
2802 modmagic = NULL;
2803
2804 /* This is allowed: modprobe --force will invalidate it. */
2805 if (!modmagic) {
2806 err = try_to_force_load(mod, "bad vermagic");
2807 if (err)
2808 return err;
2809 } else if (!same_magic(modmagic, vermagic, info->index.vers)) {
2810 pr_err("%s: version magic '%s' should be '%s'\n",
2811 mod->name, modmagic, vermagic);
2812 return -ENOEXEC;
2813 }
2814
2815 if (!get_modinfo(info, "intree"))
2816 add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
2817
2818 if (get_modinfo(info, "staging")) {
2819 add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
2820 pr_warn("%s: module is from the staging directory, the quality "
2821 "is unknown, you have been warned.\n", mod->name);
2822 }
2823
2824 /* Set up license info based on the info section */
2825 set_license(mod, get_modinfo(info, "license"));
2826
2827 return 0;
2828}
2829
2830static int find_module_sections(struct module *mod, struct load_info *info)
2831{
2832 mod->kp = section_objs(info, "__param",
2833 sizeof(*mod->kp), &mod->num_kp);
2834 mod->syms = section_objs(info, "__ksymtab",
2835 sizeof(*mod->syms), &mod->num_syms);
2836 mod->crcs = section_addr(info, "__kcrctab");
2837 mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
2838 sizeof(*mod->gpl_syms),
2839 &mod->num_gpl_syms);
2840 mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
2841 mod->gpl_future_syms = section_objs(info,
2842 "__ksymtab_gpl_future",
2843 sizeof(*mod->gpl_future_syms),
2844 &mod->num_gpl_future_syms);
2845 mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future");
2846
2847#ifdef CONFIG_UNUSED_SYMBOLS
2848 mod->unused_syms = section_objs(info, "__ksymtab_unused",
2849 sizeof(*mod->unused_syms),
2850 &mod->num_unused_syms);
2851 mod->unused_crcs = section_addr(info, "__kcrctab_unused");
2852 mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl",
2853 sizeof(*mod->unused_gpl_syms),
2854 &mod->num_unused_gpl_syms);
2855 mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl");
2856#endif
2857#ifdef CONFIG_CONSTRUCTORS
2858 mod->ctors = section_objs(info, ".ctors",
2859 sizeof(*mod->ctors), &mod->num_ctors);
2860 if (!mod->ctors)
2861 mod->ctors = section_objs(info, ".init_array",
2862 sizeof(*mod->ctors), &mod->num_ctors);
2863 else if (find_sec(info, ".init_array")) {
2864 /*
2865 * This shouldn't happen with same compiler and binutils
2866 * building all parts of the module.
2867 */
2868 pr_warn("%s: has both .ctors and .init_array.\n",
2869 mod->name);
2870 return -EINVAL;
2871 }
2872#endif
2873
2874#ifdef CONFIG_TRACEPOINTS
2875 mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
2876 sizeof(*mod->tracepoints_ptrs),
2877 &mod->num_tracepoints);
2878#endif
2879#ifdef HAVE_JUMP_LABEL
2880 mod->jump_entries = section_objs(info, "__jump_table",
2881 sizeof(*mod->jump_entries),
2882 &mod->num_jump_entries);
2883#endif
2884#ifdef CONFIG_EVENT_TRACING
2885 mod->trace_events = section_objs(info, "_ftrace_events",
2886 sizeof(*mod->trace_events),
2887 &mod->num_trace_events);
2888 mod->trace_enums = section_objs(info, "_ftrace_enum_map",
2889 sizeof(*mod->trace_enums),
2890 &mod->num_trace_enums);
2891#endif
2892#ifdef CONFIG_TRACING
2893 mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
2894 sizeof(*mod->trace_bprintk_fmt_start),
2895 &mod->num_trace_bprintk_fmt);
2896#endif
2897#ifdef CONFIG_FTRACE_MCOUNT_RECORD
2898 /* sechdrs[0].sh_size is always zero */
2899 mod->ftrace_callsites = section_objs(info, "__mcount_loc",
2900 sizeof(*mod->ftrace_callsites),
2901 &mod->num_ftrace_callsites);
2902#endif
2903
2904 mod->extable = section_objs(info, "__ex_table",
2905 sizeof(*mod->extable), &mod->num_exentries);
2906
2907 if (section_addr(info, "__obsparm"))
2908 pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
2909
2910 info->debug = section_objs(info, "__verbose",
2911 sizeof(*info->debug), &info->num_debug);
2912
2913 return 0;
2914}
2915
2916static int move_module(struct module *mod, struct load_info *info)
2917{
2918 int i;
2919 void *ptr;
2920
2921 /* Do the allocs. */
2922 ptr = module_alloc(mod->core_layout.size);
2923 /*
2924 * The pointer to this block is stored in the module structure
2925 * which is inside the block. Just mark it as not being a
2926 * leak.
2927 */
2928 kmemleak_not_leak(ptr);
2929 if (!ptr)
2930 return -ENOMEM;
2931
2932 memset(ptr, 0, mod->core_layout.size);
2933 mod->core_layout.base = ptr;
2934
2935 if (mod->init_layout.size) {
2936 ptr = module_alloc(mod->init_layout.size);
2937 /*
2938 * The pointer to this block is stored in the module structure
2939 * which is inside the block. This block doesn't need to be
2940 * scanned as it contains data and code that will be freed
2941 * after the module is initialized.
2942 */
2943 kmemleak_ignore(ptr);
2944 if (!ptr) {
2945 module_memfree(mod->core_layout.base);
2946 return -ENOMEM;
2947 }
2948 memset(ptr, 0, mod->init_layout.size);
2949 mod->init_layout.base = ptr;
2950 } else
2951 mod->init_layout.base = NULL;
2952
2953 /* Transfer each section which specifies SHF_ALLOC */
2954 pr_debug("final section addresses:\n");
2955 for (i = 0; i < info->hdr->e_shnum; i++) {
2956 void *dest;
2957 Elf_Shdr *shdr = &info->sechdrs[i];
2958
2959 if (!(shdr->sh_flags & SHF_ALLOC))
2960 continue;
2961
2962 if (shdr->sh_entsize & INIT_OFFSET_MASK)
2963 dest = mod->init_layout.base
2964 + (shdr->sh_entsize & ~INIT_OFFSET_MASK);
2965 else
2966 dest = mod->core_layout.base + shdr->sh_entsize;
2967
2968 if (shdr->sh_type != SHT_NOBITS)
2969 memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
2970 /* Update sh_addr to point to copy in image. */
2971 shdr->sh_addr = (unsigned long)dest;
2972 pr_debug("\t0x%lx %s\n",
2973 (long)shdr->sh_addr, info->secstrings + shdr->sh_name);
2974 }
2975
2976 return 0;
2977}
2978
2979static int check_module_license_and_versions(struct module *mod)
2980{
2981 /*
2982 * ndiswrapper is under GPL by itself, but loads proprietary modules.
2983 * Don't use add_taint_module(), as it would prevent ndiswrapper from
2984 * using GPL-only symbols it needs.
2985 */
2986 if (strcmp(mod->name, "ndiswrapper") == 0)
2987 add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
2988
2989 /* driverloader was caught wrongly pretending to be under GPL */
2990 if (strcmp(mod->name, "driverloader") == 0)
2991 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2992 LOCKDEP_NOW_UNRELIABLE);
2993
2994 /* lve claims to be GPL but upstream won't provide source */
2995 if (strcmp(mod->name, "lve") == 0)
2996 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2997 LOCKDEP_NOW_UNRELIABLE);
2998
2999#ifdef CONFIG_MODVERSIONS
3000 if ((mod->num_syms && !mod->crcs)
3001 || (mod->num_gpl_syms && !mod->gpl_crcs)
3002 || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
3003#ifdef CONFIG_UNUSED_SYMBOLS
3004 || (mod->num_unused_syms && !mod->unused_crcs)
3005 || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
3006#endif
3007 ) {
3008 return try_to_force_load(mod,
3009 "no versions for exported symbols");
3010 }
3011#endif
3012 return 0;
3013}
3014
3015static void flush_module_icache(const struct module *mod)
3016{
3017 mm_segment_t old_fs;
3018
3019 /* flush the icache in correct context */
3020 old_fs = get_fs();
3021 set_fs(KERNEL_DS);
3022
3023 /*
3024 * Flush the instruction cache, since we've played with text.
3025 * Do it before processing of module parameters, so the module
3026 * can provide parameter accessor functions of its own.
3027 */
3028 if (mod->init_layout.base)
3029 flush_icache_range((unsigned long)mod->init_layout.base,
3030 (unsigned long)mod->init_layout.base
3031 + mod->init_layout.size);
3032 flush_icache_range((unsigned long)mod->core_layout.base,
3033 (unsigned long)mod->core_layout.base + mod->core_layout.size);
3034
3035 set_fs(old_fs);
3036}
3037
3038int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
3039 Elf_Shdr *sechdrs,
3040 char *secstrings,
3041 struct module *mod)
3042{
3043 return 0;
3044}
3045
3046static struct module *layout_and_allocate(struct load_info *info, int flags)
3047{
3048 /* Module within temporary copy. */
3049 struct module *mod;
3050 int err;
3051
3052 mod = setup_load_info(info, flags);
3053 if (IS_ERR(mod))
3054 return mod;
3055
3056 err = check_modinfo(mod, info, flags);
3057 if (err)
3058 return ERR_PTR(err);
3059
3060 /* Allow arches to frob section contents and sizes. */
3061 err = module_frob_arch_sections(info->hdr, info->sechdrs,
3062 info->secstrings, mod);
3063 if (err < 0)
3064 return ERR_PTR(err);
3065
3066 /* We will do a special allocation for per-cpu sections later. */
3067 info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC;
3068
3069 /* Determine total sizes, and put offsets in sh_entsize. For now
3070 this is done generically; there doesn't appear to be any
3071 special cases for the architectures. */
3072 layout_sections(mod, info);
3073 layout_symtab(mod, info);
3074
3075 /* Allocate and move to the final place */
3076 err = move_module(mod, info);
3077 if (err)
3078 return ERR_PTR(err);
3079
3080 /* Module has been copied to its final place now: return it. */
3081 mod = (void *)info->sechdrs[info->index.mod].sh_addr;
3082 kmemleak_load_module(mod, info);
3083 return mod;
3084}
3085
3086/* mod is no longer valid after this! */
3087static void module_deallocate(struct module *mod, struct load_info *info)
3088{
3089 percpu_modfree(mod);
3090 module_arch_freeing_init(mod);
3091 module_memfree(mod->init_layout.base);
3092 module_memfree(mod->core_layout.base);
3093}
3094
3095int __weak module_finalize(const Elf_Ehdr *hdr,
3096 const Elf_Shdr *sechdrs,
3097 struct module *me)
3098{
3099 return 0;
3100}
3101
3102static int post_relocation(struct module *mod, const struct load_info *info)
3103{
3104 /* Sort exception table now relocations are done. */
3105 sort_extable(mod->extable, mod->extable + mod->num_exentries);
3106
3107 /* Copy relocated percpu area over. */
3108 percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
3109 info->sechdrs[info->index.pcpu].sh_size);
3110
3111 /* Setup kallsyms-specific fields. */
3112 add_kallsyms(mod, info);
3113
3114 /* Arch-specific module finalizing. */
3115 return module_finalize(info->hdr, info->sechdrs, mod);
3116}
3117
3118/* Is this module of this name done loading? No locks held. */
3119static bool finished_loading(const char *name)
3120{
3121 struct module *mod;
3122 bool ret;
3123
3124 /*
3125 * The module_mutex should not be a heavily contended lock;
3126 * if we get the occasional sleep here, we'll go an extra iteration
3127 * in the wait_event_interruptible(), which is harmless.
3128 */
3129 sched_annotate_sleep();
3130 mutex_lock(&module_mutex);
3131 mod = find_module_all(name, strlen(name), true);
3132 ret = !mod || mod->state == MODULE_STATE_LIVE
3133 || mod->state == MODULE_STATE_GOING;
3134 mutex_unlock(&module_mutex);
3135
3136 return ret;
3137}
3138
3139/* Call module constructors. */
3140static void do_mod_ctors(struct module *mod)
3141{
3142#ifdef CONFIG_CONSTRUCTORS
3143 unsigned long i;
3144
3145 for (i = 0; i < mod->num_ctors; i++)
3146 mod->ctors[i]();
3147#endif
3148}
3149
3150/* For freeing module_init on success, in case kallsyms traversing */
3151struct mod_initfree {
3152 struct rcu_head rcu;
3153 void *module_init;
3154};
3155
3156static void do_free_init(struct rcu_head *head)
3157{
3158 struct mod_initfree *m = container_of(head, struct mod_initfree, rcu);
3159 module_memfree(m->module_init);
3160 kfree(m);
3161}
3162
3163/*
3164 * This is where the real work happens.
3165 *
3166 * Keep it uninlined to provide a reliable breakpoint target, e.g. for the gdb
3167 * helper command 'lx-symbols'.
3168 */
3169static noinline int do_init_module(struct module *mod)
3170{
3171 int ret = 0;
3172 struct mod_initfree *freeinit;
3173
3174 freeinit = kmalloc(sizeof(*freeinit), GFP_KERNEL);
3175 if (!freeinit) {
3176 ret = -ENOMEM;
3177 goto fail;
3178 }
3179 freeinit->module_init = mod->init_layout.base;
3180
3181 /*
3182 * We want to find out whether @mod uses async during init. Clear
3183 * PF_USED_ASYNC. async_schedule*() will set it.
3184 */
3185 current->flags &= ~PF_USED_ASYNC;
3186
3187 do_mod_ctors(mod);
3188 /* Start the module */
3189 if (mod->init != NULL)
3190 ret = do_one_initcall(mod->init);
3191 if (ret < 0) {
3192 goto fail_free_freeinit;
3193 }
3194 if (ret > 0) {
3195 pr_warn("%s: '%s'->init suspiciously returned %d, it should "
3196 "follow 0/-E convention\n"
3197 "%s: loading module anyway...\n",
3198 __func__, mod->name, ret, __func__);
3199 dump_stack();
3200 }
3201
3202 /* Now it's a first class citizen! */
3203 mod->state = MODULE_STATE_LIVE;
3204 blocking_notifier_call_chain(&module_notify_list,
3205 MODULE_STATE_LIVE, mod);
3206
3207 /*
3208 * We need to finish all async code before the module init sequence
3209 * is done. This has potential to deadlock. For example, a newly
3210 * detected block device can trigger request_module() of the
3211 * default iosched from async probing task. Once userland helper
3212 * reaches here, async_synchronize_full() will wait on the async
3213 * task waiting on request_module() and deadlock.
3214 *
3215 * This deadlock is avoided by perfomring async_synchronize_full()
3216 * iff module init queued any async jobs. This isn't a full
3217 * solution as it will deadlock the same if module loading from
3218 * async jobs nests more than once; however, due to the various
3219 * constraints, this hack seems to be the best option for now.
3220 * Please refer to the following thread for details.
3221 *
3222 * http://thread.gmane.org/gmane.linux.kernel/1420814
3223 */
3224 if (!mod->async_probe_requested && (current->flags & PF_USED_ASYNC))
3225 async_synchronize_full();
3226
3227 mutex_lock(&module_mutex);
3228 /* Drop initial reference. */
3229 module_put(mod);
3230 trim_init_extable(mod);
3231#ifdef CONFIG_KALLSYMS
3232 /* Switch to core kallsyms now init is done: kallsyms may be walking! */
3233 rcu_assign_pointer(mod->kallsyms, &mod->core_kallsyms);
3234#endif
3235 mod_tree_remove_init(mod);
3236 disable_ro_nx(&mod->init_layout);
3237 module_arch_freeing_init(mod);
3238 mod->init_layout.base = NULL;
3239 mod->init_layout.size = 0;
3240 mod->init_layout.ro_size = 0;
3241 mod->init_layout.text_size = 0;
3242 /*
3243 * We want to free module_init, but be aware that kallsyms may be
3244 * walking this with preempt disabled. In all the failure paths, we
3245 * call synchronize_sched(), but we don't want to slow down the success
3246 * path, so use actual RCU here.
3247 */
3248 call_rcu_sched(&freeinit->rcu, do_free_init);
3249 mutex_unlock(&module_mutex);
3250 wake_up_all(&module_wq);
3251
3252 return 0;
3253
3254fail_free_freeinit:
3255 kfree(freeinit);
3256fail:
3257 /* Try to protect us from buggy refcounters. */
3258 mod->state = MODULE_STATE_GOING;
3259 synchronize_sched();
3260 module_put(mod);
3261 blocking_notifier_call_chain(&module_notify_list,
3262 MODULE_STATE_GOING, mod);
3263 klp_module_going(mod);
3264 ftrace_release_mod(mod);
3265 free_module(mod);
3266 wake_up_all(&module_wq);
3267 return ret;
3268}
3269
3270static int may_init_module(void)
3271{
3272 if (!capable(CAP_SYS_MODULE) || modules_disabled)
3273 return -EPERM;
3274
3275 return 0;
3276}
3277
3278/*
3279 * We try to place it in the list now to make sure it's unique before
3280 * we dedicate too many resources. In particular, temporary percpu
3281 * memory exhaustion.
3282 */
3283static int add_unformed_module(struct module *mod)
3284{
3285 int err;
3286 struct module *old;
3287
3288 mod->state = MODULE_STATE_UNFORMED;
3289
3290again:
3291 mutex_lock(&module_mutex);
3292 old = find_module_all(mod->name, strlen(mod->name), true);
3293 if (old != NULL) {
3294 if (old->state == MODULE_STATE_COMING
3295 || old->state == MODULE_STATE_UNFORMED) {
3296 /* Wait in case it fails to load. */
3297 mutex_unlock(&module_mutex);
3298 err = wait_event_interruptible(module_wq,
3299 finished_loading(mod->name));
3300 if (err)
3301 goto out_unlocked;
3302 goto again;
3303 }
3304 err = -EEXIST;
3305 goto out;
3306 }
3307 mod_update_bounds(mod);
3308 list_add_rcu(&mod->list, &modules);
3309 mod_tree_insert(mod);
3310 err = 0;
3311
3312out:
3313 mutex_unlock(&module_mutex);
3314out_unlocked:
3315 return err;
3316}
3317
3318static int complete_formation(struct module *mod, struct load_info *info)
3319{
3320 int err;
3321
3322 mutex_lock(&module_mutex);
3323
3324 /* Find duplicate symbols (must be called under lock). */
3325 err = verify_export_symbols(mod);
3326 if (err < 0)
3327 goto out;
3328
3329 /* This relies on module_mutex for list integrity. */
3330 module_bug_finalize(info->hdr, info->sechdrs, mod);
3331
3332 /* Set RO and NX regions */
3333 module_enable_ro(mod);
3334 module_enable_nx(mod);
3335
3336 /* Mark state as coming so strong_try_module_get() ignores us,
3337 * but kallsyms etc. can see us. */
3338 mod->state = MODULE_STATE_COMING;
3339 mutex_unlock(&module_mutex);
3340
3341 return 0;
3342
3343out:
3344 mutex_unlock(&module_mutex);
3345 return err;
3346}
3347
3348static int prepare_coming_module(struct module *mod)
3349{
3350 int err;
3351
3352 ftrace_module_enable(mod);
3353 err = klp_module_coming(mod);
3354 if (err)
3355 return err;
3356
3357 blocking_notifier_call_chain(&module_notify_list,
3358 MODULE_STATE_COMING, mod);
3359 return 0;
3360}
3361
3362static int unknown_module_param_cb(char *param, char *val, const char *modname,
3363 void *arg)
3364{
3365 struct module *mod = arg;
3366 int ret;
3367
3368 if (strcmp(param, "async_probe") == 0) {
3369 mod->async_probe_requested = true;
3370 return 0;
3371 }
3372
3373 /* Check for magic 'dyndbg' arg */
3374 ret = ddebug_dyndbg_module_param_cb(param, val, modname);
3375 if (ret != 0)
3376 pr_warn("%s: unknown parameter '%s' ignored\n", modname, param);
3377 return 0;
3378}
3379
3380/* Allocate and load the module: note that size of section 0 is always
3381 zero, and we rely on this for optional sections. */
3382static int load_module(struct load_info *info, const char __user *uargs,
3383 int flags)
3384{
3385 struct module *mod;
3386 long err;
3387 char *after_dashes;
3388
3389 err = module_sig_check(info);
3390 if (err)
3391 goto free_copy;
3392
3393 err = elf_header_check(info);
3394 if (err)
3395 goto free_copy;
3396
3397 /* Figure out module layout, and allocate all the memory. */
3398 mod = layout_and_allocate(info, flags);
3399 if (IS_ERR(mod)) {
3400 err = PTR_ERR(mod);
3401 goto free_copy;
3402 }
3403
3404 /* Reserve our place in the list. */
3405 err = add_unformed_module(mod);
3406 if (err)
3407 goto free_module;
3408
3409#ifdef CONFIG_MODULE_SIG
3410 mod->sig_ok = info->sig_ok;
3411 if (!mod->sig_ok) {
3412 pr_notice_once("%s: module verification failed: signature "
3413 "and/or required key missing - tainting "
3414 "kernel\n", mod->name);
3415 add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK);
3416 }
3417#endif
3418
3419 /* To avoid stressing percpu allocator, do this once we're unique. */
3420 err = percpu_modalloc(mod, info);
3421 if (err)
3422 goto unlink_mod;
3423
3424 /* Now module is in final location, initialize linked lists, etc. */
3425 err = module_unload_init(mod);
3426 if (err)
3427 goto unlink_mod;
3428
3429 init_param_lock(mod);
3430
3431 /* Now we've got everything in the final locations, we can
3432 * find optional sections. */
3433 err = find_module_sections(mod, info);
3434 if (err)
3435 goto free_unload;
3436
3437 err = check_module_license_and_versions(mod);
3438 if (err)
3439 goto free_unload;
3440
3441 /* Set up MODINFO_ATTR fields */
3442 setup_modinfo(mod, info);
3443
3444 /* Fix up syms, so that st_value is a pointer to location. */
3445 err = simplify_symbols(mod, info);
3446 if (err < 0)
3447 goto free_modinfo;
3448
3449 err = apply_relocations(mod, info);
3450 if (err < 0)
3451 goto free_modinfo;
3452
3453 err = post_relocation(mod, info);
3454 if (err < 0)
3455 goto free_modinfo;
3456
3457 flush_module_icache(mod);
3458
3459 /* Now copy in args */
3460 mod->args = strndup_user(uargs, ~0UL >> 1);
3461 if (IS_ERR(mod->args)) {
3462 err = PTR_ERR(mod->args);
3463 goto free_arch_cleanup;
3464 }
3465
3466 dynamic_debug_setup(info->debug, info->num_debug);
3467
3468 /* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
3469 ftrace_module_init(mod);
3470
3471 /* Finally it's fully formed, ready to start executing. */
3472 err = complete_formation(mod, info);
3473 if (err)
3474 goto ddebug_cleanup;
3475
3476 err = prepare_coming_module(mod);
3477 if (err)
3478 goto bug_cleanup;
3479
3480 /* Module is ready to execute: parsing args may do that. */
3481 after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
3482 -32768, 32767, mod,
3483 unknown_module_param_cb);
3484 if (IS_ERR(after_dashes)) {
3485 err = PTR_ERR(after_dashes);
3486 goto coming_cleanup;
3487 } else if (after_dashes) {
3488 pr_warn("%s: parameters '%s' after `--' ignored\n",
3489 mod->name, after_dashes);
3490 }
3491
3492 /* Link in to syfs. */
3493 err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
3494 if (err < 0)
3495 goto coming_cleanup;
3496
3497 /* Get rid of temporary copy. */
3498 free_copy(info);
3499
3500 /* Done! */
3501 trace_module_load(mod);
3502
3503 return do_init_module(mod);
3504
3505 coming_cleanup:
3506 blocking_notifier_call_chain(&module_notify_list,
3507 MODULE_STATE_GOING, mod);
3508 klp_module_going(mod);
3509
3510 bug_cleanup:
3511 /* module_bug_cleanup needs module_mutex protection */
3512 mutex_lock(&module_mutex);
3513 module_bug_cleanup(mod);
3514 mutex_unlock(&module_mutex);
3515
3516 /* we can't deallocate the module until we clear memory protection */
3517 module_disable_ro(mod);
3518 module_disable_nx(mod);
3519
3520 ddebug_cleanup:
3521 dynamic_debug_remove(info->debug);
3522 synchronize_sched();
3523 kfree(mod->args);
3524 free_arch_cleanup:
3525 module_arch_cleanup(mod);
3526 free_modinfo:
3527 free_modinfo(mod);
3528 free_unload:
3529 module_unload_free(mod);
3530 unlink_mod:
3531 mutex_lock(&module_mutex);
3532 /* Unlink carefully: kallsyms could be walking list. */
3533 list_del_rcu(&mod->list);
3534 mod_tree_remove(mod);
3535 wake_up_all(&module_wq);
3536 /* Wait for RCU-sched synchronizing before releasing mod->list. */
3537 synchronize_sched();
3538 mutex_unlock(&module_mutex);
3539 free_module:
3540 /*
3541 * Ftrace needs to clean up what it initialized.
3542 * This does nothing if ftrace_module_init() wasn't called,
3543 * but it must be called outside of module_mutex.
3544 */
3545 ftrace_release_mod(mod);
3546 /* Free lock-classes; relies on the preceding sync_rcu() */
3547 lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
3548
3549 module_deallocate(mod, info);
3550 free_copy:
3551 free_copy(info);
3552 return err;
3553}
3554
3555SYSCALL_DEFINE3(init_module, void __user *, umod,
3556 unsigned long, len, const char __user *, uargs)
3557{
3558 int err;
3559 struct load_info info = { };
3560
3561 err = may_init_module();
3562 if (err)
3563 return err;
3564
3565 pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
3566 umod, len, uargs);
3567
3568 err = copy_module_from_user(umod, len, &info);
3569 if (err)
3570 return err;
3571
3572 return load_module(&info, uargs, 0);
3573}
3574
3575SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
3576{
3577 struct load_info info = { };
3578 loff_t size;
3579 void *hdr;
3580 int err;
3581
3582 err = may_init_module();
3583 if (err)
3584 return err;
3585
3586 pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags);
3587
3588 if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS
3589 |MODULE_INIT_IGNORE_VERMAGIC))
3590 return -EINVAL;
3591
3592 err = kernel_read_file_from_fd(fd, &hdr, &size, INT_MAX,
3593 READING_MODULE);
3594 if (err)
3595 return err;
3596 info.hdr = hdr;
3597 info.len = size;
3598
3599 return load_module(&info, uargs, flags);
3600}
3601
3602static inline int within(unsigned long addr, void *start, unsigned long size)
3603{
3604 return ((void *)addr >= start && (void *)addr < start + size);
3605}
3606
3607#ifdef CONFIG_KALLSYMS
3608/*
3609 * This ignores the intensely annoying "mapping symbols" found
3610 * in ARM ELF files: $a, $t and $d.
3611 */
3612static inline int is_arm_mapping_symbol(const char *str)
3613{
3614 if (str[0] == '.' && str[1] == 'L')
3615 return true;
3616 return str[0] == '$' && strchr("axtd", str[1])
3617 && (str[2] == '\0' || str[2] == '.');
3618}
3619
3620static const char *symname(struct mod_kallsyms *kallsyms, unsigned int symnum)
3621{
3622 return kallsyms->strtab + kallsyms->symtab[symnum].st_name;
3623}
3624
3625static const char *get_ksymbol(struct module *mod,
3626 unsigned long addr,
3627 unsigned long *size,
3628 unsigned long *offset)
3629{
3630 unsigned int i, best = 0;
3631 unsigned long nextval;
3632 struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
3633
3634 /* At worse, next value is at end of module */
3635 if (within_module_init(addr, mod))
3636 nextval = (unsigned long)mod->init_layout.base+mod->init_layout.text_size;
3637 else
3638 nextval = (unsigned long)mod->core_layout.base+mod->core_layout.text_size;
3639
3640 /* Scan for closest preceding symbol, and next symbol. (ELF
3641 starts real symbols at 1). */
3642 for (i = 1; i < kallsyms->num_symtab; i++) {
3643 if (kallsyms->symtab[i].st_shndx == SHN_UNDEF)
3644 continue;
3645
3646 /* We ignore unnamed symbols: they're uninformative
3647 * and inserted at a whim. */
3648 if (*symname(kallsyms, i) == '\0'
3649 || is_arm_mapping_symbol(symname(kallsyms, i)))
3650 continue;
3651
3652 if (kallsyms->symtab[i].st_value <= addr
3653 && kallsyms->symtab[i].st_value > kallsyms->symtab[best].st_value)
3654 best = i;
3655 if (kallsyms->symtab[i].st_value > addr
3656 && kallsyms->symtab[i].st_value < nextval)
3657 nextval = kallsyms->symtab[i].st_value;
3658 }
3659
3660 if (!best)
3661 return NULL;
3662
3663 if (size)
3664 *size = nextval - kallsyms->symtab[best].st_value;
3665 if (offset)
3666 *offset = addr - kallsyms->symtab[best].st_value;
3667 return symname(kallsyms, best);
3668}
3669
3670/* For kallsyms to ask for address resolution. NULL means not found. Careful
3671 * not to lock to avoid deadlock on oopses, simply disable preemption. */
3672const char *module_address_lookup(unsigned long addr,
3673 unsigned long *size,
3674 unsigned long *offset,
3675 char **modname,
3676 char *namebuf)
3677{
3678 const char *ret = NULL;
3679 struct module *mod;
3680
3681 preempt_disable();
3682 mod = __module_address(addr);
3683 if (mod) {
3684 if (modname)
3685 *modname = mod->name;
3686 ret = get_ksymbol(mod, addr, size, offset);
3687 }
3688 /* Make a copy in here where it's safe */
3689 if (ret) {
3690 strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
3691 ret = namebuf;
3692 }
3693 preempt_enable();
3694
3695 return ret;
3696}
3697
3698int lookup_module_symbol_name(unsigned long addr, char *symname)
3699{
3700 struct module *mod;
3701
3702 preempt_disable();
3703 list_for_each_entry_rcu(mod, &modules, list) {
3704 if (mod->state == MODULE_STATE_UNFORMED)
3705 continue;
3706 if (within_module(addr, mod)) {
3707 const char *sym;
3708
3709 sym = get_ksymbol(mod, addr, NULL, NULL);
3710 if (!sym)
3711 goto out;
3712 strlcpy(symname, sym, KSYM_NAME_LEN);
3713 preempt_enable();
3714 return 0;
3715 }
3716 }
3717out:
3718 preempt_enable();
3719 return -ERANGE;
3720}
3721
3722int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
3723 unsigned long *offset, char *modname, char *name)
3724{
3725 struct module *mod;
3726
3727 preempt_disable();
3728 list_for_each_entry_rcu(mod, &modules, list) {
3729 if (mod->state == MODULE_STATE_UNFORMED)
3730 continue;
3731 if (within_module(addr, mod)) {
3732 const char *sym;
3733
3734 sym = get_ksymbol(mod, addr, size, offset);
3735 if (!sym)
3736 goto out;
3737 if (modname)
3738 strlcpy(modname, mod->name, MODULE_NAME_LEN);
3739 if (name)
3740 strlcpy(name, sym, KSYM_NAME_LEN);
3741 preempt_enable();
3742 return 0;
3743 }
3744 }
3745out:
3746 preempt_enable();
3747 return -ERANGE;
3748}
3749
3750int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
3751 char *name, char *module_name, int *exported)
3752{
3753 struct module *mod;
3754
3755 preempt_disable();
3756 list_for_each_entry_rcu(mod, &modules, list) {
3757 struct mod_kallsyms *kallsyms;
3758
3759 if (mod->state == MODULE_STATE_UNFORMED)
3760 continue;
3761 kallsyms = rcu_dereference_sched(mod->kallsyms);
3762 if (symnum < kallsyms->num_symtab) {
3763 *value = kallsyms->symtab[symnum].st_value;
3764 *type = kallsyms->symtab[symnum].st_info;
3765 strlcpy(name, symname(kallsyms, symnum), KSYM_NAME_LEN);
3766 strlcpy(module_name, mod->name, MODULE_NAME_LEN);
3767 *exported = is_exported(name, *value, mod);
3768 preempt_enable();
3769 return 0;
3770 }
3771 symnum -= kallsyms->num_symtab;
3772 }
3773 preempt_enable();
3774 return -ERANGE;
3775}
3776
3777static unsigned long mod_find_symname(struct module *mod, const char *name)
3778{
3779 unsigned int i;
3780 struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
3781
3782 for (i = 0; i < kallsyms->num_symtab; i++)
3783 if (strcmp(name, symname(kallsyms, i)) == 0 &&
3784 kallsyms->symtab[i].st_info != 'U')
3785 return kallsyms->symtab[i].st_value;
3786 return 0;
3787}
3788
3789/* Look for this name: can be of form module:name. */
3790unsigned long module_kallsyms_lookup_name(const char *name)
3791{
3792 struct module *mod;
3793 char *colon;
3794 unsigned long ret = 0;
3795
3796 /* Don't lock: we're in enough trouble already. */
3797 preempt_disable();
3798 if ((colon = strchr(name, ':')) != NULL) {
3799 if ((mod = find_module_all(name, colon - name, false)) != NULL)
3800 ret = mod_find_symname(mod, colon+1);
3801 } else {
3802 list_for_each_entry_rcu(mod, &modules, list) {
3803 if (mod->state == MODULE_STATE_UNFORMED)
3804 continue;
3805 if ((ret = mod_find_symname(mod, name)) != 0)
3806 break;
3807 }
3808 }
3809 preempt_enable();
3810 return ret;
3811}
3812
3813int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
3814 struct module *, unsigned long),
3815 void *data)
3816{
3817 struct module *mod;
3818 unsigned int i;
3819 int ret;
3820
3821 module_assert_mutex();
3822
3823 list_for_each_entry(mod, &modules, list) {
3824 /* We hold module_mutex: no need for rcu_dereference_sched */
3825 struct mod_kallsyms *kallsyms = mod->kallsyms;
3826
3827 if (mod->state == MODULE_STATE_UNFORMED)
3828 continue;
3829 for (i = 0; i < kallsyms->num_symtab; i++) {
3830 ret = fn(data, symname(kallsyms, i),
3831 mod, kallsyms->symtab[i].st_value);
3832 if (ret != 0)
3833 return ret;
3834 }
3835 }
3836 return 0;
3837}
3838#endif /* CONFIG_KALLSYMS */
3839
3840static char *module_flags(struct module *mod, char *buf)
3841{
3842 int bx = 0;
3843
3844 BUG_ON(mod->state == MODULE_STATE_UNFORMED);
3845 if (mod->taints ||
3846 mod->state == MODULE_STATE_GOING ||
3847 mod->state == MODULE_STATE_COMING) {
3848 buf[bx++] = '(';
3849 bx += module_flags_taint(mod, buf + bx);
3850 /* Show a - for module-is-being-unloaded */
3851 if (mod->state == MODULE_STATE_GOING)
3852 buf[bx++] = '-';
3853 /* Show a + for module-is-being-loaded */
3854 if (mod->state == MODULE_STATE_COMING)
3855 buf[bx++] = '+';
3856 buf[bx++] = ')';
3857 }
3858 buf[bx] = '\0';
3859
3860 return buf;
3861}
3862
3863#ifdef CONFIG_PROC_FS
3864/* Called by the /proc file system to return a list of modules. */
3865static void *m_start(struct seq_file *m, loff_t *pos)
3866{
3867 mutex_lock(&module_mutex);
3868 return seq_list_start(&modules, *pos);
3869}
3870
3871static void *m_next(struct seq_file *m, void *p, loff_t *pos)
3872{
3873 return seq_list_next(p, &modules, pos);
3874}
3875
3876static void m_stop(struct seq_file *m, void *p)
3877{
3878 mutex_unlock(&module_mutex);
3879}
3880
3881static int m_show(struct seq_file *m, void *p)
3882{
3883 struct module *mod = list_entry(p, struct module, list);
3884 char buf[8];
3885
3886 /* We always ignore unformed modules. */
3887 if (mod->state == MODULE_STATE_UNFORMED)
3888 return 0;
3889
3890 seq_printf(m, "%s %u",
3891 mod->name, mod->init_layout.size + mod->core_layout.size);
3892 print_unload_info(m, mod);
3893
3894 /* Informative for users. */
3895 seq_printf(m, " %s",
3896 mod->state == MODULE_STATE_GOING ? "Unloading" :
3897 mod->state == MODULE_STATE_COMING ? "Loading" :
3898 "Live");
3899 /* Used by oprofile and other similar tools. */
3900 seq_printf(m, " 0x%pK", mod->core_layout.base);
3901
3902 /* Taints info */
3903 if (mod->taints)
3904 seq_printf(m, " %s", module_flags(mod, buf));
3905
3906 seq_puts(m, "\n");
3907 return 0;
3908}
3909
3910/* Format: modulename size refcount deps address
3911
3912 Where refcount is a number or -, and deps is a comma-separated list
3913 of depends or -.
3914*/
3915static const struct seq_operations modules_op = {
3916 .start = m_start,
3917 .next = m_next,
3918 .stop = m_stop,
3919 .show = m_show
3920};
3921
3922static int modules_open(struct inode *inode, struct file *file)
3923{
3924 return seq_open(file, &modules_op);
3925}
3926
3927static const struct file_operations proc_modules_operations = {
3928 .open = modules_open,
3929 .read = seq_read,
3930 .llseek = seq_lseek,
3931 .release = seq_release,
3932};
3933
3934static int __init proc_modules_init(void)
3935{
3936 proc_create("modules", 0, NULL, &proc_modules_operations);
3937 return 0;
3938}
3939module_init(proc_modules_init);
3940#endif
3941
3942/* Given an address, look for it in the module exception tables. */
3943const struct exception_table_entry *search_module_extables(unsigned long addr)
3944{
3945 const struct exception_table_entry *e = NULL;
3946 struct module *mod;
3947
3948 preempt_disable();
3949 list_for_each_entry_rcu(mod, &modules, list) {
3950 if (mod->state == MODULE_STATE_UNFORMED)
3951 continue;
3952 if (mod->num_exentries == 0)
3953 continue;
3954
3955 e = search_extable(mod->extable,
3956 mod->extable + mod->num_exentries - 1,
3957 addr);
3958 if (e)
3959 break;
3960 }
3961 preempt_enable();
3962
3963 /* Now, if we found one, we are running inside it now, hence
3964 we cannot unload the module, hence no refcnt needed. */
3965 return e;
3966}
3967
3968/*
3969 * is_module_address - is this address inside a module?
3970 * @addr: the address to check.
3971 *
3972 * See is_module_text_address() if you simply want to see if the address
3973 * is code (not data).
3974 */
3975bool is_module_address(unsigned long addr)
3976{
3977 bool ret;
3978
3979 preempt_disable();
3980 ret = __module_address(addr) != NULL;
3981 preempt_enable();
3982
3983 return ret;
3984}
3985
3986/*
3987 * __module_address - get the module which contains an address.
3988 * @addr: the address.
3989 *
3990 * Must be called with preempt disabled or module mutex held so that
3991 * module doesn't get freed during this.
3992 */
3993struct module *__module_address(unsigned long addr)
3994{
3995 struct module *mod;
3996
3997 if (addr < module_addr_min || addr > module_addr_max)
3998 return NULL;
3999
4000 module_assert_mutex_or_preempt();
4001
4002 mod = mod_find(addr);
4003 if (mod) {
4004 BUG_ON(!within_module(addr, mod));
4005 if (mod->state == MODULE_STATE_UNFORMED)
4006 mod = NULL;
4007 }
4008 return mod;
4009}
4010EXPORT_SYMBOL_GPL(__module_address);
4011
4012/*
4013 * is_module_text_address - is this address inside module code?
4014 * @addr: the address to check.
4015 *
4016 * See is_module_address() if you simply want to see if the address is
4017 * anywhere in a module. See kernel_text_address() for testing if an
4018 * address corresponds to kernel or module code.
4019 */
4020bool is_module_text_address(unsigned long addr)
4021{
4022 bool ret;
4023
4024 preempt_disable();
4025 ret = __module_text_address(addr) != NULL;
4026 preempt_enable();
4027
4028 return ret;
4029}
4030
4031/*
4032 * __module_text_address - get the module whose code contains an address.
4033 * @addr: the address.
4034 *
4035 * Must be called with preempt disabled or module mutex held so that
4036 * module doesn't get freed during this.
4037 */
4038struct module *__module_text_address(unsigned long addr)
4039{
4040 struct module *mod = __module_address(addr);
4041 if (mod) {
4042 /* Make sure it's within the text section. */
4043 if (!within(addr, mod->init_layout.base, mod->init_layout.text_size)
4044 && !within(addr, mod->core_layout.base, mod->core_layout.text_size))
4045 mod = NULL;
4046 }
4047 return mod;
4048}
4049EXPORT_SYMBOL_GPL(__module_text_address);
4050
4051/* Don't grab lock, we're oopsing. */
4052void print_modules(void)
4053{
4054 struct module *mod;
4055 char buf[8];
4056
4057 printk(KERN_DEFAULT "Modules linked in:");
4058 /* Most callers should already have preempt disabled, but make sure */
4059 preempt_disable();
4060 list_for_each_entry_rcu(mod, &modules, list) {
4061 if (mod->state == MODULE_STATE_UNFORMED)
4062 continue;
4063 pr_cont(" %s%s", mod->name, module_flags(mod, buf));
4064 }
4065 preempt_enable();
4066 if (last_unloaded_module[0])
4067 pr_cont(" [last unloaded: %s]", last_unloaded_module);
4068 pr_cont("\n");
4069}
4070
4071#ifdef CONFIG_MODVERSIONS
4072/* Generate the signature for all relevant module structures here.
4073 * If these change, we don't want to try to parse the module. */
4074void module_layout(struct module *mod,
4075 struct modversion_info *ver,
4076 struct kernel_param *kp,
4077 struct kernel_symbol *ks,
4078 struct tracepoint * const *tp)
4079{
4080}
4081EXPORT_SYMBOL(module_layout);
4082#endif