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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 <linux/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 <linux/dynamic_debug.h>
64#include <uapi/linux/module.h>
65#include "module-internal.h"
66
67#define CREATE_TRACE_POINTS
68#include <trace/events/module.h>
69
70#ifndef ARCH_SHF_SMALL
71#define ARCH_SHF_SMALL 0
72#endif
73
74/*
75 * Modules' sections will be aligned on page boundaries
76 * to ensure complete separation of code and data, but
77 * only when CONFIG_DEBUG_SET_MODULE_RONX=y
78 */
79#ifdef CONFIG_DEBUG_SET_MODULE_RONX
80# define debug_align(X) ALIGN(X, PAGE_SIZE)
81#else
82# define debug_align(X) (X)
83#endif
84
85/* If this is set, the section belongs in the init part of the module */
86#define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
87
88/*
89 * Mutex protects:
90 * 1) List of modules (also safely readable with preempt_disable),
91 * 2) module_use links,
92 * 3) module_addr_min/module_addr_max.
93 * (delete and add uses RCU list operations). */
94DEFINE_MUTEX(module_mutex);
95EXPORT_SYMBOL_GPL(module_mutex);
96static LIST_HEAD(modules);
97
98#ifdef CONFIG_MODULES_TREE_LOOKUP
99
100/*
101 * Use a latched RB-tree for __module_address(); this allows us to use
102 * RCU-sched lookups of the address from any context.
103 *
104 * This is conditional on PERF_EVENTS || TRACING because those can really hit
105 * __module_address() hard by doing a lot of stack unwinding; potentially from
106 * NMI context.
107 */
108
109static __always_inline unsigned long __mod_tree_val(struct latch_tree_node *n)
110{
111 struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
112
113 return (unsigned long)layout->base;
114}
115
116static __always_inline unsigned long __mod_tree_size(struct latch_tree_node *n)
117{
118 struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
119
120 return (unsigned long)layout->size;
121}
122
123static __always_inline bool
124mod_tree_less(struct latch_tree_node *a, struct latch_tree_node *b)
125{
126 return __mod_tree_val(a) < __mod_tree_val(b);
127}
128
129static __always_inline int
130mod_tree_comp(void *key, struct latch_tree_node *n)
131{
132 unsigned long val = (unsigned long)key;
133 unsigned long start, end;
134
135 start = __mod_tree_val(n);
136 if (val < start)
137 return -1;
138
139 end = start + __mod_tree_size(n);
140 if (val >= end)
141 return 1;
142
143 return 0;
144}
145
146static const struct latch_tree_ops mod_tree_ops = {
147 .less = mod_tree_less,
148 .comp = mod_tree_comp,
149};
150
151static struct mod_tree_root {
152 struct latch_tree_root root;
153 unsigned long addr_min;
154 unsigned long addr_max;
155} mod_tree __cacheline_aligned = {
156 .addr_min = -1UL,
157};
158
159#define module_addr_min mod_tree.addr_min
160#define module_addr_max mod_tree.addr_max
161
162static noinline void __mod_tree_insert(struct mod_tree_node *node)
163{
164 latch_tree_insert(&node->node, &mod_tree.root, &mod_tree_ops);
165}
166
167static void __mod_tree_remove(struct mod_tree_node *node)
168{
169 latch_tree_erase(&node->node, &mod_tree.root, &mod_tree_ops);
170}
171
172/*
173 * These modifications: insert, remove_init and remove; are serialized by the
174 * module_mutex.
175 */
176static void mod_tree_insert(struct module *mod)
177{
178 mod->core_layout.mtn.mod = mod;
179 mod->init_layout.mtn.mod = mod;
180
181 __mod_tree_insert(&mod->core_layout.mtn);
182 if (mod->init_layout.size)
183 __mod_tree_insert(&mod->init_layout.mtn);
184}
185
186static void mod_tree_remove_init(struct module *mod)
187{
188 if (mod->init_layout.size)
189 __mod_tree_remove(&mod->init_layout.mtn);
190}
191
192static void mod_tree_remove(struct module *mod)
193{
194 __mod_tree_remove(&mod->core_layout.mtn);
195 mod_tree_remove_init(mod);
196}
197
198static struct module *mod_find(unsigned long addr)
199{
200 struct latch_tree_node *ltn;
201
202 ltn = latch_tree_find((void *)addr, &mod_tree.root, &mod_tree_ops);
203 if (!ltn)
204 return NULL;
205
206 return container_of(ltn, struct mod_tree_node, node)->mod;
207}
208
209#else /* MODULES_TREE_LOOKUP */
210
211static unsigned long module_addr_min = -1UL, module_addr_max = 0;
212
213static void mod_tree_insert(struct module *mod) { }
214static void mod_tree_remove_init(struct module *mod) { }
215static void mod_tree_remove(struct module *mod) { }
216
217static struct module *mod_find(unsigned long addr)
218{
219 struct module *mod;
220
221 list_for_each_entry_rcu(mod, &modules, list) {
222 if (within_module(addr, mod))
223 return mod;
224 }
225
226 return NULL;
227}
228
229#endif /* MODULES_TREE_LOOKUP */
230
231/*
232 * Bounds of module text, for speeding up __module_address.
233 * Protected by module_mutex.
234 */
235static void __mod_update_bounds(void *base, unsigned int size)
236{
237 unsigned long min = (unsigned long)base;
238 unsigned long max = min + size;
239
240 if (min < module_addr_min)
241 module_addr_min = min;
242 if (max > module_addr_max)
243 module_addr_max = max;
244}
245
246static void mod_update_bounds(struct module *mod)
247{
248 __mod_update_bounds(mod->core_layout.base, mod->core_layout.size);
249 if (mod->init_layout.size)
250 __mod_update_bounds(mod->init_layout.base, mod->init_layout.size);
251}
252
253#ifdef CONFIG_KGDB_KDB
254struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
255#endif /* CONFIG_KGDB_KDB */
256
257static void module_assert_mutex(void)
258{
259 lockdep_assert_held(&module_mutex);
260}
261
262static void module_assert_mutex_or_preempt(void)
263{
264#ifdef CONFIG_LOCKDEP
265 if (unlikely(!debug_locks))
266 return;
267
268 WARN_ON_ONCE(!rcu_read_lock_sched_held() &&
269 !lockdep_is_held(&module_mutex));
270#endif
271}
272
273static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE);
274#ifndef CONFIG_MODULE_SIG_FORCE
275module_param(sig_enforce, bool_enable_only, 0644);
276#endif /* !CONFIG_MODULE_SIG_FORCE */
277
278/* Block module loading/unloading? */
279int modules_disabled = 0;
280core_param(nomodule, modules_disabled, bint, 0);
281
282/* Waiting for a module to finish initializing? */
283static DECLARE_WAIT_QUEUE_HEAD(module_wq);
284
285static BLOCKING_NOTIFIER_HEAD(module_notify_list);
286
287int register_module_notifier(struct notifier_block *nb)
288{
289 return blocking_notifier_chain_register(&module_notify_list, nb);
290}
291EXPORT_SYMBOL(register_module_notifier);
292
293int unregister_module_notifier(struct notifier_block *nb)
294{
295 return blocking_notifier_chain_unregister(&module_notify_list, nb);
296}
297EXPORT_SYMBOL(unregister_module_notifier);
298
299struct load_info {
300 Elf_Ehdr *hdr;
301 unsigned long len;
302 Elf_Shdr *sechdrs;
303 char *secstrings, *strtab;
304 unsigned long symoffs, stroffs;
305 struct _ddebug *debug;
306 unsigned int num_debug;
307 bool sig_ok;
308#ifdef CONFIG_KALLSYMS
309 unsigned long mod_kallsyms_init_off;
310#endif
311 struct {
312 unsigned int sym, str, mod, vers, info, pcpu;
313 } index;
314};
315
316/*
317 * We require a truly strong try_module_get(): 0 means success.
318 * Otherwise an error is returned due to ongoing or failed
319 * initialization etc.
320 */
321static inline int strong_try_module_get(struct module *mod)
322{
323 BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED);
324 if (mod && mod->state == MODULE_STATE_COMING)
325 return -EBUSY;
326 if (try_module_get(mod))
327 return 0;
328 else
329 return -ENOENT;
330}
331
332static inline void add_taint_module(struct module *mod, unsigned flag,
333 enum lockdep_ok lockdep_ok)
334{
335 add_taint(flag, lockdep_ok);
336 set_bit(flag, &mod->taints);
337}
338
339/*
340 * A thread that wants to hold a reference to a module only while it
341 * is running can call this to safely exit. nfsd and lockd use this.
342 */
343void __noreturn __module_put_and_exit(struct module *mod, long code)
344{
345 module_put(mod);
346 do_exit(code);
347}
348EXPORT_SYMBOL(__module_put_and_exit);
349
350/* Find a module section: 0 means not found. */
351static unsigned int find_sec(const struct load_info *info, const char *name)
352{
353 unsigned int i;
354
355 for (i = 1; i < info->hdr->e_shnum; i++) {
356 Elf_Shdr *shdr = &info->sechdrs[i];
357 /* Alloc bit cleared means "ignore it." */
358 if ((shdr->sh_flags & SHF_ALLOC)
359 && strcmp(info->secstrings + shdr->sh_name, name) == 0)
360 return i;
361 }
362 return 0;
363}
364
365/* Find a module section, or NULL. */
366static void *section_addr(const struct load_info *info, const char *name)
367{
368 /* Section 0 has sh_addr 0. */
369 return (void *)info->sechdrs[find_sec(info, name)].sh_addr;
370}
371
372/* Find a module section, or NULL. Fill in number of "objects" in section. */
373static void *section_objs(const struct load_info *info,
374 const char *name,
375 size_t object_size,
376 unsigned int *num)
377{
378 unsigned int sec = find_sec(info, name);
379
380 /* Section 0 has sh_addr 0 and sh_size 0. */
381 *num = info->sechdrs[sec].sh_size / object_size;
382 return (void *)info->sechdrs[sec].sh_addr;
383}
384
385/* Provided by the linker */
386extern const struct kernel_symbol __start___ksymtab[];
387extern const struct kernel_symbol __stop___ksymtab[];
388extern const struct kernel_symbol __start___ksymtab_gpl[];
389extern const struct kernel_symbol __stop___ksymtab_gpl[];
390extern const struct kernel_symbol __start___ksymtab_gpl_future[];
391extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
392extern const s32 __start___kcrctab[];
393extern const s32 __start___kcrctab_gpl[];
394extern const s32 __start___kcrctab_gpl_future[];
395#ifdef CONFIG_UNUSED_SYMBOLS
396extern const struct kernel_symbol __start___ksymtab_unused[];
397extern const struct kernel_symbol __stop___ksymtab_unused[];
398extern const struct kernel_symbol __start___ksymtab_unused_gpl[];
399extern const struct kernel_symbol __stop___ksymtab_unused_gpl[];
400extern const s32 __start___kcrctab_unused[];
401extern const s32 __start___kcrctab_unused_gpl[];
402#endif
403
404#ifndef CONFIG_MODVERSIONS
405#define symversion(base, idx) NULL
406#else
407#define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
408#endif
409
410static bool each_symbol_in_section(const struct symsearch *arr,
411 unsigned int arrsize,
412 struct module *owner,
413 bool (*fn)(const struct symsearch *syms,
414 struct module *owner,
415 void *data),
416 void *data)
417{
418 unsigned int j;
419
420 for (j = 0; j < arrsize; j++) {
421 if (fn(&arr[j], owner, data))
422 return true;
423 }
424
425 return false;
426}
427
428/* Returns true as soon as fn returns true, otherwise false. */
429bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
430 struct module *owner,
431 void *data),
432 void *data)
433{
434 struct module *mod;
435 static const struct symsearch arr[] = {
436 { __start___ksymtab, __stop___ksymtab, __start___kcrctab,
437 NOT_GPL_ONLY, false },
438 { __start___ksymtab_gpl, __stop___ksymtab_gpl,
439 __start___kcrctab_gpl,
440 GPL_ONLY, false },
441 { __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future,
442 __start___kcrctab_gpl_future,
443 WILL_BE_GPL_ONLY, false },
444#ifdef CONFIG_UNUSED_SYMBOLS
445 { __start___ksymtab_unused, __stop___ksymtab_unused,
446 __start___kcrctab_unused,
447 NOT_GPL_ONLY, true },
448 { __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl,
449 __start___kcrctab_unused_gpl,
450 GPL_ONLY, true },
451#endif
452 };
453
454 module_assert_mutex_or_preempt();
455
456 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data))
457 return true;
458
459 list_for_each_entry_rcu(mod, &modules, list) {
460 struct symsearch arr[] = {
461 { mod->syms, mod->syms + mod->num_syms, mod->crcs,
462 NOT_GPL_ONLY, false },
463 { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
464 mod->gpl_crcs,
465 GPL_ONLY, false },
466 { mod->gpl_future_syms,
467 mod->gpl_future_syms + mod->num_gpl_future_syms,
468 mod->gpl_future_crcs,
469 WILL_BE_GPL_ONLY, false },
470#ifdef CONFIG_UNUSED_SYMBOLS
471 { mod->unused_syms,
472 mod->unused_syms + mod->num_unused_syms,
473 mod->unused_crcs,
474 NOT_GPL_ONLY, true },
475 { mod->unused_gpl_syms,
476 mod->unused_gpl_syms + mod->num_unused_gpl_syms,
477 mod->unused_gpl_crcs,
478 GPL_ONLY, true },
479#endif
480 };
481
482 if (mod->state == MODULE_STATE_UNFORMED)
483 continue;
484
485 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data))
486 return true;
487 }
488 return false;
489}
490EXPORT_SYMBOL_GPL(each_symbol_section);
491
492struct find_symbol_arg {
493 /* Input */
494 const char *name;
495 bool gplok;
496 bool warn;
497
498 /* Output */
499 struct module *owner;
500 const s32 *crc;
501 const struct kernel_symbol *sym;
502};
503
504static bool check_symbol(const struct symsearch *syms,
505 struct module *owner,
506 unsigned int symnum, void *data)
507{
508 struct find_symbol_arg *fsa = data;
509
510 if (!fsa->gplok) {
511 if (syms->licence == GPL_ONLY)
512 return false;
513 if (syms->licence == WILL_BE_GPL_ONLY && fsa->warn) {
514 pr_warn("Symbol %s is being used by a non-GPL module, "
515 "which will not be allowed in the future\n",
516 fsa->name);
517 }
518 }
519
520#ifdef CONFIG_UNUSED_SYMBOLS
521 if (syms->unused && fsa->warn) {
522 pr_warn("Symbol %s is marked as UNUSED, however this module is "
523 "using it.\n", fsa->name);
524 pr_warn("This symbol will go away in the future.\n");
525 pr_warn("Please evaluate if this is the right api to use and "
526 "if it really is, submit a report to the linux kernel "
527 "mailing list together with submitting your code for "
528 "inclusion.\n");
529 }
530#endif
531
532 fsa->owner = owner;
533 fsa->crc = symversion(syms->crcs, symnum);
534 fsa->sym = &syms->start[symnum];
535 return true;
536}
537
538static int cmp_name(const void *va, const void *vb)
539{
540 const char *a;
541 const struct kernel_symbol *b;
542 a = va; b = vb;
543 return strcmp(a, b->name);
544}
545
546static bool find_symbol_in_section(const struct symsearch *syms,
547 struct module *owner,
548 void *data)
549{
550 struct find_symbol_arg *fsa = data;
551 struct kernel_symbol *sym;
552
553 sym = bsearch(fsa->name, syms->start, syms->stop - syms->start,
554 sizeof(struct kernel_symbol), cmp_name);
555
556 if (sym != NULL && check_symbol(syms, owner, sym - syms->start, data))
557 return true;
558
559 return false;
560}
561
562/* Find a symbol and return it, along with, (optional) crc and
563 * (optional) module which owns it. Needs preempt disabled or module_mutex. */
564const struct kernel_symbol *find_symbol(const char *name,
565 struct module **owner,
566 const s32 **crc,
567 bool gplok,
568 bool warn)
569{
570 struct find_symbol_arg fsa;
571
572 fsa.name = name;
573 fsa.gplok = gplok;
574 fsa.warn = warn;
575
576 if (each_symbol_section(find_symbol_in_section, &fsa)) {
577 if (owner)
578 *owner = fsa.owner;
579 if (crc)
580 *crc = fsa.crc;
581 return fsa.sym;
582 }
583
584 pr_debug("Failed to find symbol %s\n", name);
585 return NULL;
586}
587EXPORT_SYMBOL_GPL(find_symbol);
588
589/*
590 * Search for module by name: must hold module_mutex (or preempt disabled
591 * for read-only access).
592 */
593static struct module *find_module_all(const char *name, size_t len,
594 bool even_unformed)
595{
596 struct module *mod;
597
598 module_assert_mutex_or_preempt();
599
600 list_for_each_entry(mod, &modules, list) {
601 if (!even_unformed && mod->state == MODULE_STATE_UNFORMED)
602 continue;
603 if (strlen(mod->name) == len && !memcmp(mod->name, name, len))
604 return mod;
605 }
606 return NULL;
607}
608
609struct module *find_module(const char *name)
610{
611 module_assert_mutex();
612 return find_module_all(name, strlen(name), false);
613}
614EXPORT_SYMBOL_GPL(find_module);
615
616#ifdef CONFIG_SMP
617
618static inline void __percpu *mod_percpu(struct module *mod)
619{
620 return mod->percpu;
621}
622
623static int percpu_modalloc(struct module *mod, struct load_info *info)
624{
625 Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu];
626 unsigned long align = pcpusec->sh_addralign;
627
628 if (!pcpusec->sh_size)
629 return 0;
630
631 if (align > PAGE_SIZE) {
632 pr_warn("%s: per-cpu alignment %li > %li\n",
633 mod->name, align, PAGE_SIZE);
634 align = PAGE_SIZE;
635 }
636
637 mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align);
638 if (!mod->percpu) {
639 pr_warn("%s: Could not allocate %lu bytes percpu data\n",
640 mod->name, (unsigned long)pcpusec->sh_size);
641 return -ENOMEM;
642 }
643 mod->percpu_size = pcpusec->sh_size;
644 return 0;
645}
646
647static void percpu_modfree(struct module *mod)
648{
649 free_percpu(mod->percpu);
650}
651
652static unsigned int find_pcpusec(struct load_info *info)
653{
654 return find_sec(info, ".data..percpu");
655}
656
657static void percpu_modcopy(struct module *mod,
658 const void *from, unsigned long size)
659{
660 int cpu;
661
662 for_each_possible_cpu(cpu)
663 memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
664}
665
666/**
667 * is_module_percpu_address - test whether address is from module static percpu
668 * @addr: address to test
669 *
670 * Test whether @addr belongs to module static percpu area.
671 *
672 * RETURNS:
673 * %true if @addr is from module static percpu area
674 */
675bool is_module_percpu_address(unsigned long addr)
676{
677 struct module *mod;
678 unsigned int cpu;
679
680 preempt_disable();
681
682 list_for_each_entry_rcu(mod, &modules, list) {
683 if (mod->state == MODULE_STATE_UNFORMED)
684 continue;
685 if (!mod->percpu_size)
686 continue;
687 for_each_possible_cpu(cpu) {
688 void *start = per_cpu_ptr(mod->percpu, cpu);
689
690 if ((void *)addr >= start &&
691 (void *)addr < start + mod->percpu_size) {
692 preempt_enable();
693 return true;
694 }
695 }
696 }
697
698 preempt_enable();
699 return false;
700}
701
702#else /* ... !CONFIG_SMP */
703
704static inline void __percpu *mod_percpu(struct module *mod)
705{
706 return NULL;
707}
708static int percpu_modalloc(struct module *mod, struct load_info *info)
709{
710 /* UP modules shouldn't have this section: ENOMEM isn't quite right */
711 if (info->sechdrs[info->index.pcpu].sh_size != 0)
712 return -ENOMEM;
713 return 0;
714}
715static inline void percpu_modfree(struct module *mod)
716{
717}
718static unsigned int find_pcpusec(struct load_info *info)
719{
720 return 0;
721}
722static inline void percpu_modcopy(struct module *mod,
723 const void *from, unsigned long size)
724{
725 /* pcpusec should be 0, and size of that section should be 0. */
726 BUG_ON(size != 0);
727}
728bool is_module_percpu_address(unsigned long addr)
729{
730 return false;
731}
732
733#endif /* CONFIG_SMP */
734
735#define MODINFO_ATTR(field) \
736static void setup_modinfo_##field(struct module *mod, const char *s) \
737{ \
738 mod->field = kstrdup(s, GFP_KERNEL); \
739} \
740static ssize_t show_modinfo_##field(struct module_attribute *mattr, \
741 struct module_kobject *mk, char *buffer) \
742{ \
743 return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field); \
744} \
745static int modinfo_##field##_exists(struct module *mod) \
746{ \
747 return mod->field != NULL; \
748} \
749static void free_modinfo_##field(struct module *mod) \
750{ \
751 kfree(mod->field); \
752 mod->field = NULL; \
753} \
754static struct module_attribute modinfo_##field = { \
755 .attr = { .name = __stringify(field), .mode = 0444 }, \
756 .show = show_modinfo_##field, \
757 .setup = setup_modinfo_##field, \
758 .test = modinfo_##field##_exists, \
759 .free = free_modinfo_##field, \
760};
761
762MODINFO_ATTR(version);
763MODINFO_ATTR(srcversion);
764
765static char last_unloaded_module[MODULE_NAME_LEN+1];
766
767#ifdef CONFIG_MODULE_UNLOAD
768
769EXPORT_TRACEPOINT_SYMBOL(module_get);
770
771/* MODULE_REF_BASE is the base reference count by kmodule loader. */
772#define MODULE_REF_BASE 1
773
774/* Init the unload section of the module. */
775static int module_unload_init(struct module *mod)
776{
777 /*
778 * Initialize reference counter to MODULE_REF_BASE.
779 * refcnt == 0 means module is going.
780 */
781 atomic_set(&mod->refcnt, MODULE_REF_BASE);
782
783 INIT_LIST_HEAD(&mod->source_list);
784 INIT_LIST_HEAD(&mod->target_list);
785
786 /* Hold reference count during initialization. */
787 atomic_inc(&mod->refcnt);
788
789 return 0;
790}
791
792/* Does a already use b? */
793static int already_uses(struct module *a, struct module *b)
794{
795 struct module_use *use;
796
797 list_for_each_entry(use, &b->source_list, source_list) {
798 if (use->source == a) {
799 pr_debug("%s uses %s!\n", a->name, b->name);
800 return 1;
801 }
802 }
803 pr_debug("%s does not use %s!\n", a->name, b->name);
804 return 0;
805}
806
807/*
808 * Module a uses b
809 * - we add 'a' as a "source", 'b' as a "target" of module use
810 * - the module_use is added to the list of 'b' sources (so
811 * 'b' can walk the list to see who sourced them), and of 'a'
812 * targets (so 'a' can see what modules it targets).
813 */
814static int add_module_usage(struct module *a, struct module *b)
815{
816 struct module_use *use;
817
818 pr_debug("Allocating new usage for %s.\n", a->name);
819 use = kmalloc(sizeof(*use), GFP_ATOMIC);
820 if (!use) {
821 pr_warn("%s: out of memory loading\n", a->name);
822 return -ENOMEM;
823 }
824
825 use->source = a;
826 use->target = b;
827 list_add(&use->source_list, &b->source_list);
828 list_add(&use->target_list, &a->target_list);
829 return 0;
830}
831
832/* Module a uses b: caller needs module_mutex() */
833int ref_module(struct module *a, struct module *b)
834{
835 int err;
836
837 if (b == NULL || already_uses(a, b))
838 return 0;
839
840 /* If module isn't available, we fail. */
841 err = strong_try_module_get(b);
842 if (err)
843 return err;
844
845 err = add_module_usage(a, b);
846 if (err) {
847 module_put(b);
848 return err;
849 }
850 return 0;
851}
852EXPORT_SYMBOL_GPL(ref_module);
853
854/* Clear the unload stuff of the module. */
855static void module_unload_free(struct module *mod)
856{
857 struct module_use *use, *tmp;
858
859 mutex_lock(&module_mutex);
860 list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
861 struct module *i = use->target;
862 pr_debug("%s unusing %s\n", mod->name, i->name);
863 module_put(i);
864 list_del(&use->source_list);
865 list_del(&use->target_list);
866 kfree(use);
867 }
868 mutex_unlock(&module_mutex);
869}
870
871#ifdef CONFIG_MODULE_FORCE_UNLOAD
872static inline int try_force_unload(unsigned int flags)
873{
874 int ret = (flags & O_TRUNC);
875 if (ret)
876 add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE);
877 return ret;
878}
879#else
880static inline int try_force_unload(unsigned int flags)
881{
882 return 0;
883}
884#endif /* CONFIG_MODULE_FORCE_UNLOAD */
885
886/* Try to release refcount of module, 0 means success. */
887static int try_release_module_ref(struct module *mod)
888{
889 int ret;
890
891 /* Try to decrement refcnt which we set at loading */
892 ret = atomic_sub_return(MODULE_REF_BASE, &mod->refcnt);
893 BUG_ON(ret < 0);
894 if (ret)
895 /* Someone can put this right now, recover with checking */
896 ret = atomic_add_unless(&mod->refcnt, MODULE_REF_BASE, 0);
897
898 return ret;
899}
900
901static int try_stop_module(struct module *mod, int flags, int *forced)
902{
903 /* If it's not unused, quit unless we're forcing. */
904 if (try_release_module_ref(mod) != 0) {
905 *forced = try_force_unload(flags);
906 if (!(*forced))
907 return -EWOULDBLOCK;
908 }
909
910 /* Mark it as dying. */
911 mod->state = MODULE_STATE_GOING;
912
913 return 0;
914}
915
916/**
917 * module_refcount - return the refcount or -1 if unloading
918 *
919 * @mod: the module we're checking
920 *
921 * Returns:
922 * -1 if the module is in the process of unloading
923 * otherwise the number of references in the kernel to the module
924 */
925int module_refcount(struct module *mod)
926{
927 return atomic_read(&mod->refcnt) - MODULE_REF_BASE;
928}
929EXPORT_SYMBOL(module_refcount);
930
931/* This exists whether we can unload or not */
932static void free_module(struct module *mod);
933
934SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
935 unsigned int, flags)
936{
937 struct module *mod;
938 char name[MODULE_NAME_LEN];
939 int ret, forced = 0;
940
941 if (!capable(CAP_SYS_MODULE) || modules_disabled)
942 return -EPERM;
943
944 if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
945 return -EFAULT;
946 name[MODULE_NAME_LEN-1] = '\0';
947
948 if (mutex_lock_interruptible(&module_mutex) != 0)
949 return -EINTR;
950
951 mod = find_module(name);
952 if (!mod) {
953 ret = -ENOENT;
954 goto out;
955 }
956
957 if (!list_empty(&mod->source_list)) {
958 /* Other modules depend on us: get rid of them first. */
959 ret = -EWOULDBLOCK;
960 goto out;
961 }
962
963 /* Doing init or already dying? */
964 if (mod->state != MODULE_STATE_LIVE) {
965 /* FIXME: if (force), slam module count damn the torpedoes */
966 pr_debug("%s already dying\n", mod->name);
967 ret = -EBUSY;
968 goto out;
969 }
970
971 /* If it has an init func, it must have an exit func to unload */
972 if (mod->init && !mod->exit) {
973 forced = try_force_unload(flags);
974 if (!forced) {
975 /* This module can't be removed */
976 ret = -EBUSY;
977 goto out;
978 }
979 }
980
981 /* Stop the machine so refcounts can't move and disable module. */
982 ret = try_stop_module(mod, flags, &forced);
983 if (ret != 0)
984 goto out;
985
986 mutex_unlock(&module_mutex);
987 /* Final destruction now no one is using it. */
988 if (mod->exit != NULL)
989 mod->exit();
990 blocking_notifier_call_chain(&module_notify_list,
991 MODULE_STATE_GOING, mod);
992 klp_module_going(mod);
993 ftrace_release_mod(mod);
994
995 async_synchronize_full();
996
997 /* Store the name of the last unloaded module for diagnostic purposes */
998 strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
999
1000 free_module(mod);
1001 return 0;
1002out:
1003 mutex_unlock(&module_mutex);
1004 return ret;
1005}
1006
1007static inline void print_unload_info(struct seq_file *m, struct module *mod)
1008{
1009 struct module_use *use;
1010 int printed_something = 0;
1011
1012 seq_printf(m, " %i ", module_refcount(mod));
1013
1014 /*
1015 * Always include a trailing , so userspace can differentiate
1016 * between this and the old multi-field proc format.
1017 */
1018 list_for_each_entry(use, &mod->source_list, source_list) {
1019 printed_something = 1;
1020 seq_printf(m, "%s,", use->source->name);
1021 }
1022
1023 if (mod->init != NULL && mod->exit == NULL) {
1024 printed_something = 1;
1025 seq_puts(m, "[permanent],");
1026 }
1027
1028 if (!printed_something)
1029 seq_puts(m, "-");
1030}
1031
1032void __symbol_put(const char *symbol)
1033{
1034 struct module *owner;
1035
1036 preempt_disable();
1037 if (!find_symbol(symbol, &owner, NULL, true, false))
1038 BUG();
1039 module_put(owner);
1040 preempt_enable();
1041}
1042EXPORT_SYMBOL(__symbol_put);
1043
1044/* Note this assumes addr is a function, which it currently always is. */
1045void symbol_put_addr(void *addr)
1046{
1047 struct module *modaddr;
1048 unsigned long a = (unsigned long)dereference_function_descriptor(addr);
1049
1050 if (core_kernel_text(a))
1051 return;
1052
1053 /*
1054 * Even though we hold a reference on the module; we still need to
1055 * disable preemption in order to safely traverse the data structure.
1056 */
1057 preempt_disable();
1058 modaddr = __module_text_address(a);
1059 BUG_ON(!modaddr);
1060 module_put(modaddr);
1061 preempt_enable();
1062}
1063EXPORT_SYMBOL_GPL(symbol_put_addr);
1064
1065static ssize_t show_refcnt(struct module_attribute *mattr,
1066 struct module_kobject *mk, char *buffer)
1067{
1068 return sprintf(buffer, "%i\n", module_refcount(mk->mod));
1069}
1070
1071static struct module_attribute modinfo_refcnt =
1072 __ATTR(refcnt, 0444, show_refcnt, NULL);
1073
1074void __module_get(struct module *module)
1075{
1076 if (module) {
1077 preempt_disable();
1078 atomic_inc(&module->refcnt);
1079 trace_module_get(module, _RET_IP_);
1080 preempt_enable();
1081 }
1082}
1083EXPORT_SYMBOL(__module_get);
1084
1085bool try_module_get(struct module *module)
1086{
1087 bool ret = true;
1088
1089 if (module) {
1090 preempt_disable();
1091 /* Note: here, we can fail to get a reference */
1092 if (likely(module_is_live(module) &&
1093 atomic_inc_not_zero(&module->refcnt) != 0))
1094 trace_module_get(module, _RET_IP_);
1095 else
1096 ret = false;
1097
1098 preempt_enable();
1099 }
1100 return ret;
1101}
1102EXPORT_SYMBOL(try_module_get);
1103
1104void module_put(struct module *module)
1105{
1106 int ret;
1107
1108 if (module) {
1109 preempt_disable();
1110 ret = atomic_dec_if_positive(&module->refcnt);
1111 WARN_ON(ret < 0); /* Failed to put refcount */
1112 trace_module_put(module, _RET_IP_);
1113 preempt_enable();
1114 }
1115}
1116EXPORT_SYMBOL(module_put);
1117
1118#else /* !CONFIG_MODULE_UNLOAD */
1119static inline void print_unload_info(struct seq_file *m, struct module *mod)
1120{
1121 /* We don't know the usage count, or what modules are using. */
1122 seq_puts(m, " - -");
1123}
1124
1125static inline void module_unload_free(struct module *mod)
1126{
1127}
1128
1129int ref_module(struct module *a, struct module *b)
1130{
1131 return strong_try_module_get(b);
1132}
1133EXPORT_SYMBOL_GPL(ref_module);
1134
1135static inline int module_unload_init(struct module *mod)
1136{
1137 return 0;
1138}
1139#endif /* CONFIG_MODULE_UNLOAD */
1140
1141static size_t module_flags_taint(struct module *mod, char *buf)
1142{
1143 size_t l = 0;
1144 int i;
1145
1146 for (i = 0; i < TAINT_FLAGS_COUNT; i++) {
1147 if (taint_flags[i].module && test_bit(i, &mod->taints))
1148 buf[l++] = taint_flags[i].c_true;
1149 }
1150
1151 return l;
1152}
1153
1154static ssize_t show_initstate(struct module_attribute *mattr,
1155 struct module_kobject *mk, char *buffer)
1156{
1157 const char *state = "unknown";
1158
1159 switch (mk->mod->state) {
1160 case MODULE_STATE_LIVE:
1161 state = "live";
1162 break;
1163 case MODULE_STATE_COMING:
1164 state = "coming";
1165 break;
1166 case MODULE_STATE_GOING:
1167 state = "going";
1168 break;
1169 default:
1170 BUG();
1171 }
1172 return sprintf(buffer, "%s\n", state);
1173}
1174
1175static struct module_attribute modinfo_initstate =
1176 __ATTR(initstate, 0444, show_initstate, NULL);
1177
1178static ssize_t store_uevent(struct module_attribute *mattr,
1179 struct module_kobject *mk,
1180 const char *buffer, size_t count)
1181{
1182 enum kobject_action action;
1183
1184 if (kobject_action_type(buffer, count, &action) == 0)
1185 kobject_uevent(&mk->kobj, action);
1186 return count;
1187}
1188
1189struct module_attribute module_uevent =
1190 __ATTR(uevent, 0200, NULL, store_uevent);
1191
1192static ssize_t show_coresize(struct module_attribute *mattr,
1193 struct module_kobject *mk, char *buffer)
1194{
1195 return sprintf(buffer, "%u\n", mk->mod->core_layout.size);
1196}
1197
1198static struct module_attribute modinfo_coresize =
1199 __ATTR(coresize, 0444, show_coresize, NULL);
1200
1201static ssize_t show_initsize(struct module_attribute *mattr,
1202 struct module_kobject *mk, char *buffer)
1203{
1204 return sprintf(buffer, "%u\n", mk->mod->init_layout.size);
1205}
1206
1207static struct module_attribute modinfo_initsize =
1208 __ATTR(initsize, 0444, show_initsize, NULL);
1209
1210static ssize_t show_taint(struct module_attribute *mattr,
1211 struct module_kobject *mk, char *buffer)
1212{
1213 size_t l;
1214
1215 l = module_flags_taint(mk->mod, buffer);
1216 buffer[l++] = '\n';
1217 return l;
1218}
1219
1220static struct module_attribute modinfo_taint =
1221 __ATTR(taint, 0444, show_taint, NULL);
1222
1223static struct module_attribute *modinfo_attrs[] = {
1224 &module_uevent,
1225 &modinfo_version,
1226 &modinfo_srcversion,
1227 &modinfo_initstate,
1228 &modinfo_coresize,
1229 &modinfo_initsize,
1230 &modinfo_taint,
1231#ifdef CONFIG_MODULE_UNLOAD
1232 &modinfo_refcnt,
1233#endif
1234 NULL,
1235};
1236
1237static const char vermagic[] = VERMAGIC_STRING;
1238
1239static int try_to_force_load(struct module *mod, const char *reason)
1240{
1241#ifdef CONFIG_MODULE_FORCE_LOAD
1242 if (!test_taint(TAINT_FORCED_MODULE))
1243 pr_warn("%s: %s: kernel tainted.\n", mod->name, reason);
1244 add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
1245 return 0;
1246#else
1247 return -ENOEXEC;
1248#endif
1249}
1250
1251#ifdef CONFIG_MODVERSIONS
1252
1253static u32 resolve_rel_crc(const s32 *crc)
1254{
1255 return *(u32 *)((void *)crc + *crc);
1256}
1257
1258static int check_version(Elf_Shdr *sechdrs,
1259 unsigned int versindex,
1260 const char *symname,
1261 struct module *mod,
1262 const s32 *crc)
1263{
1264 unsigned int i, num_versions;
1265 struct modversion_info *versions;
1266
1267 /* Exporting module didn't supply crcs? OK, we're already tainted. */
1268 if (!crc)
1269 return 1;
1270
1271 /* No versions at all? modprobe --force does this. */
1272 if (versindex == 0)
1273 return try_to_force_load(mod, symname) == 0;
1274
1275 versions = (void *) sechdrs[versindex].sh_addr;
1276 num_versions = sechdrs[versindex].sh_size
1277 / sizeof(struct modversion_info);
1278
1279 for (i = 0; i < num_versions; i++) {
1280 u32 crcval;
1281
1282 if (strcmp(versions[i].name, symname) != 0)
1283 continue;
1284
1285 if (IS_ENABLED(CONFIG_MODULE_REL_CRCS))
1286 crcval = resolve_rel_crc(crc);
1287 else
1288 crcval = *crc;
1289 if (versions[i].crc == crcval)
1290 return 1;
1291 pr_debug("Found checksum %X vs module %lX\n",
1292 crcval, versions[i].crc);
1293 goto bad_version;
1294 }
1295
1296 /* Broken toolchain. Warn once, then let it go.. */
1297 pr_warn_once("%s: no symbol version for %s\n", mod->name, symname);
1298 return 1;
1299
1300bad_version:
1301 pr_warn("%s: disagrees about version of symbol %s\n",
1302 mod->name, symname);
1303 return 0;
1304}
1305
1306static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1307 unsigned int versindex,
1308 struct module *mod)
1309{
1310 const s32 *crc;
1311
1312 /*
1313 * Since this should be found in kernel (which can't be removed), no
1314 * locking is necessary -- use preempt_disable() to placate lockdep.
1315 */
1316 preempt_disable();
1317 if (!find_symbol(VMLINUX_SYMBOL_STR(module_layout), NULL,
1318 &crc, true, false)) {
1319 preempt_enable();
1320 BUG();
1321 }
1322 preempt_enable();
1323 return check_version(sechdrs, versindex,
1324 VMLINUX_SYMBOL_STR(module_layout), mod, crc);
1325}
1326
1327/* First part is kernel version, which we ignore if module has crcs. */
1328static inline int same_magic(const char *amagic, const char *bmagic,
1329 bool has_crcs)
1330{
1331 if (has_crcs) {
1332 amagic += strcspn(amagic, " ");
1333 bmagic += strcspn(bmagic, " ");
1334 }
1335 return strcmp(amagic, bmagic) == 0;
1336}
1337#else
1338static inline int check_version(Elf_Shdr *sechdrs,
1339 unsigned int versindex,
1340 const char *symname,
1341 struct module *mod,
1342 const s32 *crc)
1343{
1344 return 1;
1345}
1346
1347static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1348 unsigned int versindex,
1349 struct module *mod)
1350{
1351 return 1;
1352}
1353
1354static inline int same_magic(const char *amagic, const char *bmagic,
1355 bool has_crcs)
1356{
1357 return strcmp(amagic, bmagic) == 0;
1358}
1359#endif /* CONFIG_MODVERSIONS */
1360
1361/* Resolve a symbol for this module. I.e. if we find one, record usage. */
1362static const struct kernel_symbol *resolve_symbol(struct module *mod,
1363 const struct load_info *info,
1364 const char *name,
1365 char ownername[])
1366{
1367 struct module *owner;
1368 const struct kernel_symbol *sym;
1369 const s32 *crc;
1370 int err;
1371
1372 /*
1373 * The module_mutex should not be a heavily contended lock;
1374 * if we get the occasional sleep here, we'll go an extra iteration
1375 * in the wait_event_interruptible(), which is harmless.
1376 */
1377 sched_annotate_sleep();
1378 mutex_lock(&module_mutex);
1379 sym = find_symbol(name, &owner, &crc,
1380 !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
1381 if (!sym)
1382 goto unlock;
1383
1384 if (!check_version(info->sechdrs, info->index.vers, name, mod, crc)) {
1385 sym = ERR_PTR(-EINVAL);
1386 goto getname;
1387 }
1388
1389 err = ref_module(mod, owner);
1390 if (err) {
1391 sym = ERR_PTR(err);
1392 goto getname;
1393 }
1394
1395getname:
1396 /* We must make copy under the lock if we failed to get ref. */
1397 strncpy(ownername, module_name(owner), MODULE_NAME_LEN);
1398unlock:
1399 mutex_unlock(&module_mutex);
1400 return sym;
1401}
1402
1403static const struct kernel_symbol *
1404resolve_symbol_wait(struct module *mod,
1405 const struct load_info *info,
1406 const char *name)
1407{
1408 const struct kernel_symbol *ksym;
1409 char owner[MODULE_NAME_LEN];
1410
1411 if (wait_event_interruptible_timeout(module_wq,
1412 !IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
1413 || PTR_ERR(ksym) != -EBUSY,
1414 30 * HZ) <= 0) {
1415 pr_warn("%s: gave up waiting for init of module %s.\n",
1416 mod->name, owner);
1417 }
1418 return ksym;
1419}
1420
1421/*
1422 * /sys/module/foo/sections stuff
1423 * J. Corbet <corbet@lwn.net>
1424 */
1425#ifdef CONFIG_SYSFS
1426
1427#ifdef CONFIG_KALLSYMS
1428static inline bool sect_empty(const Elf_Shdr *sect)
1429{
1430 return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
1431}
1432
1433struct module_sect_attr {
1434 struct module_attribute mattr;
1435 char *name;
1436 unsigned long address;
1437};
1438
1439struct module_sect_attrs {
1440 struct attribute_group grp;
1441 unsigned int nsections;
1442 struct module_sect_attr attrs[0];
1443};
1444
1445static ssize_t module_sect_show(struct module_attribute *mattr,
1446 struct module_kobject *mk, char *buf)
1447{
1448 struct module_sect_attr *sattr =
1449 container_of(mattr, struct module_sect_attr, mattr);
1450 return sprintf(buf, "0x%pK\n", (void *)sattr->address);
1451}
1452
1453static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
1454{
1455 unsigned int section;
1456
1457 for (section = 0; section < sect_attrs->nsections; section++)
1458 kfree(sect_attrs->attrs[section].name);
1459 kfree(sect_attrs);
1460}
1461
1462static void add_sect_attrs(struct module *mod, const struct load_info *info)
1463{
1464 unsigned int nloaded = 0, i, size[2];
1465 struct module_sect_attrs *sect_attrs;
1466 struct module_sect_attr *sattr;
1467 struct attribute **gattr;
1468
1469 /* Count loaded sections and allocate structures */
1470 for (i = 0; i < info->hdr->e_shnum; i++)
1471 if (!sect_empty(&info->sechdrs[i]))
1472 nloaded++;
1473 size[0] = ALIGN(sizeof(*sect_attrs)
1474 + nloaded * sizeof(sect_attrs->attrs[0]),
1475 sizeof(sect_attrs->grp.attrs[0]));
1476 size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]);
1477 sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
1478 if (sect_attrs == NULL)
1479 return;
1480
1481 /* Setup section attributes. */
1482 sect_attrs->grp.name = "sections";
1483 sect_attrs->grp.attrs = (void *)sect_attrs + size[0];
1484
1485 sect_attrs->nsections = 0;
1486 sattr = §_attrs->attrs[0];
1487 gattr = §_attrs->grp.attrs[0];
1488 for (i = 0; i < info->hdr->e_shnum; i++) {
1489 Elf_Shdr *sec = &info->sechdrs[i];
1490 if (sect_empty(sec))
1491 continue;
1492 sattr->address = sec->sh_addr;
1493 sattr->name = kstrdup(info->secstrings + sec->sh_name,
1494 GFP_KERNEL);
1495 if (sattr->name == NULL)
1496 goto out;
1497 sect_attrs->nsections++;
1498 sysfs_attr_init(&sattr->mattr.attr);
1499 sattr->mattr.show = module_sect_show;
1500 sattr->mattr.store = NULL;
1501 sattr->mattr.attr.name = sattr->name;
1502 sattr->mattr.attr.mode = S_IRUGO;
1503 *(gattr++) = &(sattr++)->mattr.attr;
1504 }
1505 *gattr = NULL;
1506
1507 if (sysfs_create_group(&mod->mkobj.kobj, §_attrs->grp))
1508 goto out;
1509
1510 mod->sect_attrs = sect_attrs;
1511 return;
1512 out:
1513 free_sect_attrs(sect_attrs);
1514}
1515
1516static void remove_sect_attrs(struct module *mod)
1517{
1518 if (mod->sect_attrs) {
1519 sysfs_remove_group(&mod->mkobj.kobj,
1520 &mod->sect_attrs->grp);
1521 /* We are positive that no one is using any sect attrs
1522 * at this point. Deallocate immediately. */
1523 free_sect_attrs(mod->sect_attrs);
1524 mod->sect_attrs = NULL;
1525 }
1526}
1527
1528/*
1529 * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
1530 */
1531
1532struct module_notes_attrs {
1533 struct kobject *dir;
1534 unsigned int notes;
1535 struct bin_attribute attrs[0];
1536};
1537
1538static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
1539 struct bin_attribute *bin_attr,
1540 char *buf, loff_t pos, size_t count)
1541{
1542 /*
1543 * The caller checked the pos and count against our size.
1544 */
1545 memcpy(buf, bin_attr->private + pos, count);
1546 return count;
1547}
1548
1549static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
1550 unsigned int i)
1551{
1552 if (notes_attrs->dir) {
1553 while (i-- > 0)
1554 sysfs_remove_bin_file(notes_attrs->dir,
1555 ¬es_attrs->attrs[i]);
1556 kobject_put(notes_attrs->dir);
1557 }
1558 kfree(notes_attrs);
1559}
1560
1561static void add_notes_attrs(struct module *mod, const struct load_info *info)
1562{
1563 unsigned int notes, loaded, i;
1564 struct module_notes_attrs *notes_attrs;
1565 struct bin_attribute *nattr;
1566
1567 /* failed to create section attributes, so can't create notes */
1568 if (!mod->sect_attrs)
1569 return;
1570
1571 /* Count notes sections and allocate structures. */
1572 notes = 0;
1573 for (i = 0; i < info->hdr->e_shnum; i++)
1574 if (!sect_empty(&info->sechdrs[i]) &&
1575 (info->sechdrs[i].sh_type == SHT_NOTE))
1576 ++notes;
1577
1578 if (notes == 0)
1579 return;
1580
1581 notes_attrs = kzalloc(sizeof(*notes_attrs)
1582 + notes * sizeof(notes_attrs->attrs[0]),
1583 GFP_KERNEL);
1584 if (notes_attrs == NULL)
1585 return;
1586
1587 notes_attrs->notes = notes;
1588 nattr = ¬es_attrs->attrs[0];
1589 for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
1590 if (sect_empty(&info->sechdrs[i]))
1591 continue;
1592 if (info->sechdrs[i].sh_type == SHT_NOTE) {
1593 sysfs_bin_attr_init(nattr);
1594 nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
1595 nattr->attr.mode = S_IRUGO;
1596 nattr->size = info->sechdrs[i].sh_size;
1597 nattr->private = (void *) info->sechdrs[i].sh_addr;
1598 nattr->read = module_notes_read;
1599 ++nattr;
1600 }
1601 ++loaded;
1602 }
1603
1604 notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
1605 if (!notes_attrs->dir)
1606 goto out;
1607
1608 for (i = 0; i < notes; ++i)
1609 if (sysfs_create_bin_file(notes_attrs->dir,
1610 ¬es_attrs->attrs[i]))
1611 goto out;
1612
1613 mod->notes_attrs = notes_attrs;
1614 return;
1615
1616 out:
1617 free_notes_attrs(notes_attrs, i);
1618}
1619
1620static void remove_notes_attrs(struct module *mod)
1621{
1622 if (mod->notes_attrs)
1623 free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
1624}
1625
1626#else
1627
1628static inline void add_sect_attrs(struct module *mod,
1629 const struct load_info *info)
1630{
1631}
1632
1633static inline void remove_sect_attrs(struct module *mod)
1634{
1635}
1636
1637static inline void add_notes_attrs(struct module *mod,
1638 const struct load_info *info)
1639{
1640}
1641
1642static inline void remove_notes_attrs(struct module *mod)
1643{
1644}
1645#endif /* CONFIG_KALLSYMS */
1646
1647static void add_usage_links(struct module *mod)
1648{
1649#ifdef CONFIG_MODULE_UNLOAD
1650 struct module_use *use;
1651 int nowarn;
1652
1653 mutex_lock(&module_mutex);
1654 list_for_each_entry(use, &mod->target_list, target_list) {
1655 nowarn = sysfs_create_link(use->target->holders_dir,
1656 &mod->mkobj.kobj, mod->name);
1657 }
1658 mutex_unlock(&module_mutex);
1659#endif
1660}
1661
1662static void del_usage_links(struct module *mod)
1663{
1664#ifdef CONFIG_MODULE_UNLOAD
1665 struct module_use *use;
1666
1667 mutex_lock(&module_mutex);
1668 list_for_each_entry(use, &mod->target_list, target_list)
1669 sysfs_remove_link(use->target->holders_dir, mod->name);
1670 mutex_unlock(&module_mutex);
1671#endif
1672}
1673
1674static int module_add_modinfo_attrs(struct module *mod)
1675{
1676 struct module_attribute *attr;
1677 struct module_attribute *temp_attr;
1678 int error = 0;
1679 int i;
1680
1681 mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
1682 (ARRAY_SIZE(modinfo_attrs) + 1)),
1683 GFP_KERNEL);
1684 if (!mod->modinfo_attrs)
1685 return -ENOMEM;
1686
1687 temp_attr = mod->modinfo_attrs;
1688 for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
1689 if (!attr->test || attr->test(mod)) {
1690 memcpy(temp_attr, attr, sizeof(*temp_attr));
1691 sysfs_attr_init(&temp_attr->attr);
1692 error = sysfs_create_file(&mod->mkobj.kobj,
1693 &temp_attr->attr);
1694 ++temp_attr;
1695 }
1696 }
1697 return error;
1698}
1699
1700static void module_remove_modinfo_attrs(struct module *mod)
1701{
1702 struct module_attribute *attr;
1703 int i;
1704
1705 for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
1706 /* pick a field to test for end of list */
1707 if (!attr->attr.name)
1708 break;
1709 sysfs_remove_file(&mod->mkobj.kobj, &attr->attr);
1710 if (attr->free)
1711 attr->free(mod);
1712 }
1713 kfree(mod->modinfo_attrs);
1714}
1715
1716static void mod_kobject_put(struct module *mod)
1717{
1718 DECLARE_COMPLETION_ONSTACK(c);
1719 mod->mkobj.kobj_completion = &c;
1720 kobject_put(&mod->mkobj.kobj);
1721 wait_for_completion(&c);
1722}
1723
1724static int mod_sysfs_init(struct module *mod)
1725{
1726 int err;
1727 struct kobject *kobj;
1728
1729 if (!module_sysfs_initialized) {
1730 pr_err("%s: module sysfs not initialized\n", mod->name);
1731 err = -EINVAL;
1732 goto out;
1733 }
1734
1735 kobj = kset_find_obj(module_kset, mod->name);
1736 if (kobj) {
1737 pr_err("%s: module is already loaded\n", mod->name);
1738 kobject_put(kobj);
1739 err = -EINVAL;
1740 goto out;
1741 }
1742
1743 mod->mkobj.mod = mod;
1744
1745 memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
1746 mod->mkobj.kobj.kset = module_kset;
1747 err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
1748 "%s", mod->name);
1749 if (err)
1750 mod_kobject_put(mod);
1751
1752 /* delay uevent until full sysfs population */
1753out:
1754 return err;
1755}
1756
1757static int mod_sysfs_setup(struct module *mod,
1758 const struct load_info *info,
1759 struct kernel_param *kparam,
1760 unsigned int num_params)
1761{
1762 int err;
1763
1764 err = mod_sysfs_init(mod);
1765 if (err)
1766 goto out;
1767
1768 mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1769 if (!mod->holders_dir) {
1770 err = -ENOMEM;
1771 goto out_unreg;
1772 }
1773
1774 err = module_param_sysfs_setup(mod, kparam, num_params);
1775 if (err)
1776 goto out_unreg_holders;
1777
1778 err = module_add_modinfo_attrs(mod);
1779 if (err)
1780 goto out_unreg_param;
1781
1782 add_usage_links(mod);
1783 add_sect_attrs(mod, info);
1784 add_notes_attrs(mod, info);
1785
1786 kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
1787 return 0;
1788
1789out_unreg_param:
1790 module_param_sysfs_remove(mod);
1791out_unreg_holders:
1792 kobject_put(mod->holders_dir);
1793out_unreg:
1794 mod_kobject_put(mod);
1795out:
1796 return err;
1797}
1798
1799static void mod_sysfs_fini(struct module *mod)
1800{
1801 remove_notes_attrs(mod);
1802 remove_sect_attrs(mod);
1803 mod_kobject_put(mod);
1804}
1805
1806static void init_param_lock(struct module *mod)
1807{
1808 mutex_init(&mod->param_lock);
1809}
1810#else /* !CONFIG_SYSFS */
1811
1812static int mod_sysfs_setup(struct module *mod,
1813 const struct load_info *info,
1814 struct kernel_param *kparam,
1815 unsigned int num_params)
1816{
1817 return 0;
1818}
1819
1820static void mod_sysfs_fini(struct module *mod)
1821{
1822}
1823
1824static void module_remove_modinfo_attrs(struct module *mod)
1825{
1826}
1827
1828static void del_usage_links(struct module *mod)
1829{
1830}
1831
1832static void init_param_lock(struct module *mod)
1833{
1834}
1835#endif /* CONFIG_SYSFS */
1836
1837static void mod_sysfs_teardown(struct module *mod)
1838{
1839 del_usage_links(mod);
1840 module_remove_modinfo_attrs(mod);
1841 module_param_sysfs_remove(mod);
1842 kobject_put(mod->mkobj.drivers_dir);
1843 kobject_put(mod->holders_dir);
1844 mod_sysfs_fini(mod);
1845}
1846
1847#ifdef CONFIG_DEBUG_SET_MODULE_RONX
1848/*
1849 * LKM RO/NX protection: protect module's text/ro-data
1850 * from modification and any data from execution.
1851 *
1852 * General layout of module is:
1853 * [text] [read-only-data] [ro-after-init] [writable data]
1854 * text_size -----^ ^ ^ ^
1855 * ro_size ------------------------| | |
1856 * ro_after_init_size -----------------------------| |
1857 * size -----------------------------------------------------------|
1858 *
1859 * These values are always page-aligned (as is base)
1860 */
1861static void frob_text(const struct module_layout *layout,
1862 int (*set_memory)(unsigned long start, int num_pages))
1863{
1864 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1865 BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
1866 set_memory((unsigned long)layout->base,
1867 layout->text_size >> PAGE_SHIFT);
1868}
1869
1870static void frob_rodata(const struct module_layout *layout,
1871 int (*set_memory)(unsigned long start, int num_pages))
1872{
1873 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1874 BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
1875 BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
1876 set_memory((unsigned long)layout->base + layout->text_size,
1877 (layout->ro_size - layout->text_size) >> PAGE_SHIFT);
1878}
1879
1880static void frob_ro_after_init(const struct module_layout *layout,
1881 int (*set_memory)(unsigned long start, int num_pages))
1882{
1883 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1884 BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
1885 BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
1886 set_memory((unsigned long)layout->base + layout->ro_size,
1887 (layout->ro_after_init_size - layout->ro_size) >> PAGE_SHIFT);
1888}
1889
1890static void frob_writable_data(const struct module_layout *layout,
1891 int (*set_memory)(unsigned long start, int num_pages))
1892{
1893 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1894 BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
1895 BUG_ON((unsigned long)layout->size & (PAGE_SIZE-1));
1896 set_memory((unsigned long)layout->base + layout->ro_after_init_size,
1897 (layout->size - layout->ro_after_init_size) >> PAGE_SHIFT);
1898}
1899
1900/* livepatching wants to disable read-only so it can frob module. */
1901void module_disable_ro(const struct module *mod)
1902{
1903 if (!rodata_enabled)
1904 return;
1905
1906 frob_text(&mod->core_layout, set_memory_rw);
1907 frob_rodata(&mod->core_layout, set_memory_rw);
1908 frob_ro_after_init(&mod->core_layout, set_memory_rw);
1909 frob_text(&mod->init_layout, set_memory_rw);
1910 frob_rodata(&mod->init_layout, set_memory_rw);
1911}
1912
1913void module_enable_ro(const struct module *mod, bool after_init)
1914{
1915 if (!rodata_enabled)
1916 return;
1917
1918 frob_text(&mod->core_layout, set_memory_ro);
1919 frob_rodata(&mod->core_layout, set_memory_ro);
1920 frob_text(&mod->init_layout, set_memory_ro);
1921 frob_rodata(&mod->init_layout, set_memory_ro);
1922
1923 if (after_init)
1924 frob_ro_after_init(&mod->core_layout, set_memory_ro);
1925}
1926
1927static void module_enable_nx(const struct module *mod)
1928{
1929 frob_rodata(&mod->core_layout, set_memory_nx);
1930 frob_ro_after_init(&mod->core_layout, set_memory_nx);
1931 frob_writable_data(&mod->core_layout, set_memory_nx);
1932 frob_rodata(&mod->init_layout, set_memory_nx);
1933 frob_writable_data(&mod->init_layout, set_memory_nx);
1934}
1935
1936static void module_disable_nx(const struct module *mod)
1937{
1938 frob_rodata(&mod->core_layout, set_memory_x);
1939 frob_ro_after_init(&mod->core_layout, set_memory_x);
1940 frob_writable_data(&mod->core_layout, set_memory_x);
1941 frob_rodata(&mod->init_layout, set_memory_x);
1942 frob_writable_data(&mod->init_layout, set_memory_x);
1943}
1944
1945/* Iterate through all modules and set each module's text as RW */
1946void set_all_modules_text_rw(void)
1947{
1948 struct module *mod;
1949
1950 if (!rodata_enabled)
1951 return;
1952
1953 mutex_lock(&module_mutex);
1954 list_for_each_entry_rcu(mod, &modules, list) {
1955 if (mod->state == MODULE_STATE_UNFORMED)
1956 continue;
1957
1958 frob_text(&mod->core_layout, set_memory_rw);
1959 frob_text(&mod->init_layout, set_memory_rw);
1960 }
1961 mutex_unlock(&module_mutex);
1962}
1963
1964/* Iterate through all modules and set each module's text as RO */
1965void set_all_modules_text_ro(void)
1966{
1967 struct module *mod;
1968
1969 if (!rodata_enabled)
1970 return;
1971
1972 mutex_lock(&module_mutex);
1973 list_for_each_entry_rcu(mod, &modules, list) {
1974 /*
1975 * Ignore going modules since it's possible that ro
1976 * protection has already been disabled, otherwise we'll
1977 * run into protection faults at module deallocation.
1978 */
1979 if (mod->state == MODULE_STATE_UNFORMED ||
1980 mod->state == MODULE_STATE_GOING)
1981 continue;
1982
1983 frob_text(&mod->core_layout, set_memory_ro);
1984 frob_text(&mod->init_layout, set_memory_ro);
1985 }
1986 mutex_unlock(&module_mutex);
1987}
1988
1989static void disable_ro_nx(const struct module_layout *layout)
1990{
1991 if (rodata_enabled) {
1992 frob_text(layout, set_memory_rw);
1993 frob_rodata(layout, set_memory_rw);
1994 frob_ro_after_init(layout, set_memory_rw);
1995 }
1996 frob_rodata(layout, set_memory_x);
1997 frob_ro_after_init(layout, set_memory_x);
1998 frob_writable_data(layout, set_memory_x);
1999}
2000
2001#else
2002static void disable_ro_nx(const struct module_layout *layout) { }
2003static void module_enable_nx(const struct module *mod) { }
2004static void module_disable_nx(const struct module *mod) { }
2005#endif
2006
2007#ifdef CONFIG_LIVEPATCH
2008/*
2009 * Persist Elf information about a module. Copy the Elf header,
2010 * section header table, section string table, and symtab section
2011 * index from info to mod->klp_info.
2012 */
2013static int copy_module_elf(struct module *mod, struct load_info *info)
2014{
2015 unsigned int size, symndx;
2016 int ret;
2017
2018 size = sizeof(*mod->klp_info);
2019 mod->klp_info = kmalloc(size, GFP_KERNEL);
2020 if (mod->klp_info == NULL)
2021 return -ENOMEM;
2022
2023 /* Elf header */
2024 size = sizeof(mod->klp_info->hdr);
2025 memcpy(&mod->klp_info->hdr, info->hdr, size);
2026
2027 /* Elf section header table */
2028 size = sizeof(*info->sechdrs) * info->hdr->e_shnum;
2029 mod->klp_info->sechdrs = kmalloc(size, GFP_KERNEL);
2030 if (mod->klp_info->sechdrs == NULL) {
2031 ret = -ENOMEM;
2032 goto free_info;
2033 }
2034 memcpy(mod->klp_info->sechdrs, info->sechdrs, size);
2035
2036 /* Elf section name string table */
2037 size = info->sechdrs[info->hdr->e_shstrndx].sh_size;
2038 mod->klp_info->secstrings = kmalloc(size, GFP_KERNEL);
2039 if (mod->klp_info->secstrings == NULL) {
2040 ret = -ENOMEM;
2041 goto free_sechdrs;
2042 }
2043 memcpy(mod->klp_info->secstrings, info->secstrings, size);
2044
2045 /* Elf symbol section index */
2046 symndx = info->index.sym;
2047 mod->klp_info->symndx = symndx;
2048
2049 /*
2050 * For livepatch modules, core_kallsyms.symtab is a complete
2051 * copy of the original symbol table. Adjust sh_addr to point
2052 * to core_kallsyms.symtab since the copy of the symtab in module
2053 * init memory is freed at the end of do_init_module().
2054 */
2055 mod->klp_info->sechdrs[symndx].sh_addr = \
2056 (unsigned long) mod->core_kallsyms.symtab;
2057
2058 return 0;
2059
2060free_sechdrs:
2061 kfree(mod->klp_info->sechdrs);
2062free_info:
2063 kfree(mod->klp_info);
2064 return ret;
2065}
2066
2067static void free_module_elf(struct module *mod)
2068{
2069 kfree(mod->klp_info->sechdrs);
2070 kfree(mod->klp_info->secstrings);
2071 kfree(mod->klp_info);
2072}
2073#else /* !CONFIG_LIVEPATCH */
2074static int copy_module_elf(struct module *mod, struct load_info *info)
2075{
2076 return 0;
2077}
2078
2079static void free_module_elf(struct module *mod)
2080{
2081}
2082#endif /* CONFIG_LIVEPATCH */
2083
2084void __weak module_memfree(void *module_region)
2085{
2086 vfree(module_region);
2087}
2088
2089void __weak module_arch_cleanup(struct module *mod)
2090{
2091}
2092
2093void __weak module_arch_freeing_init(struct module *mod)
2094{
2095}
2096
2097/* Free a module, remove from lists, etc. */
2098static void free_module(struct module *mod)
2099{
2100 trace_module_free(mod);
2101
2102 mod_sysfs_teardown(mod);
2103
2104 /* We leave it in list to prevent duplicate loads, but make sure
2105 * that noone uses it while it's being deconstructed. */
2106 mutex_lock(&module_mutex);
2107 mod->state = MODULE_STATE_UNFORMED;
2108 mutex_unlock(&module_mutex);
2109
2110 /* Remove dynamic debug info */
2111 ddebug_remove_module(mod->name);
2112
2113 /* Arch-specific cleanup. */
2114 module_arch_cleanup(mod);
2115
2116 /* Module unload stuff */
2117 module_unload_free(mod);
2118
2119 /* Free any allocated parameters. */
2120 destroy_params(mod->kp, mod->num_kp);
2121
2122 if (is_livepatch_module(mod))
2123 free_module_elf(mod);
2124
2125 /* Now we can delete it from the lists */
2126 mutex_lock(&module_mutex);
2127 /* Unlink carefully: kallsyms could be walking list. */
2128 list_del_rcu(&mod->list);
2129 mod_tree_remove(mod);
2130 /* Remove this module from bug list, this uses list_del_rcu */
2131 module_bug_cleanup(mod);
2132 /* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */
2133 synchronize_sched();
2134 mutex_unlock(&module_mutex);
2135
2136 /* This may be empty, but that's OK */
2137 disable_ro_nx(&mod->init_layout);
2138 module_arch_freeing_init(mod);
2139 module_memfree(mod->init_layout.base);
2140 kfree(mod->args);
2141 percpu_modfree(mod);
2142
2143 /* Free lock-classes; relies on the preceding sync_rcu(). */
2144 lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
2145
2146 /* Finally, free the core (containing the module structure) */
2147 disable_ro_nx(&mod->core_layout);
2148 module_memfree(mod->core_layout.base);
2149
2150#ifdef CONFIG_MPU
2151 update_protections(current->mm);
2152#endif
2153}
2154
2155void *__symbol_get(const char *symbol)
2156{
2157 struct module *owner;
2158 const struct kernel_symbol *sym;
2159
2160 preempt_disable();
2161 sym = find_symbol(symbol, &owner, NULL, true, true);
2162 if (sym && strong_try_module_get(owner))
2163 sym = NULL;
2164 preempt_enable();
2165
2166 return sym ? (void *)sym->value : NULL;
2167}
2168EXPORT_SYMBOL_GPL(__symbol_get);
2169
2170/*
2171 * Ensure that an exported symbol [global namespace] does not already exist
2172 * in the kernel or in some other module's exported symbol table.
2173 *
2174 * You must hold the module_mutex.
2175 */
2176static int verify_export_symbols(struct module *mod)
2177{
2178 unsigned int i;
2179 struct module *owner;
2180 const struct kernel_symbol *s;
2181 struct {
2182 const struct kernel_symbol *sym;
2183 unsigned int num;
2184 } arr[] = {
2185 { mod->syms, mod->num_syms },
2186 { mod->gpl_syms, mod->num_gpl_syms },
2187 { mod->gpl_future_syms, mod->num_gpl_future_syms },
2188#ifdef CONFIG_UNUSED_SYMBOLS
2189 { mod->unused_syms, mod->num_unused_syms },
2190 { mod->unused_gpl_syms, mod->num_unused_gpl_syms },
2191#endif
2192 };
2193
2194 for (i = 0; i < ARRAY_SIZE(arr); i++) {
2195 for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
2196 if (find_symbol(s->name, &owner, NULL, true, false)) {
2197 pr_err("%s: exports duplicate symbol %s"
2198 " (owned by %s)\n",
2199 mod->name, s->name, module_name(owner));
2200 return -ENOEXEC;
2201 }
2202 }
2203 }
2204 return 0;
2205}
2206
2207/* Change all symbols so that st_value encodes the pointer directly. */
2208static int simplify_symbols(struct module *mod, const struct load_info *info)
2209{
2210 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2211 Elf_Sym *sym = (void *)symsec->sh_addr;
2212 unsigned long secbase;
2213 unsigned int i;
2214 int ret = 0;
2215 const struct kernel_symbol *ksym;
2216
2217 for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
2218 const char *name = info->strtab + sym[i].st_name;
2219
2220 switch (sym[i].st_shndx) {
2221 case SHN_COMMON:
2222 /* Ignore common symbols */
2223 if (!strncmp(name, "__gnu_lto", 9))
2224 break;
2225
2226 /* We compiled with -fno-common. These are not
2227 supposed to happen. */
2228 pr_debug("Common symbol: %s\n", name);
2229 pr_warn("%s: please compile with -fno-common\n",
2230 mod->name);
2231 ret = -ENOEXEC;
2232 break;
2233
2234 case SHN_ABS:
2235 /* Don't need to do anything */
2236 pr_debug("Absolute symbol: 0x%08lx\n",
2237 (long)sym[i].st_value);
2238 break;
2239
2240 case SHN_LIVEPATCH:
2241 /* Livepatch symbols are resolved by livepatch */
2242 break;
2243
2244 case SHN_UNDEF:
2245 ksym = resolve_symbol_wait(mod, info, name);
2246 /* Ok if resolved. */
2247 if (ksym && !IS_ERR(ksym)) {
2248 sym[i].st_value = ksym->value;
2249 break;
2250 }
2251
2252 /* Ok if weak. */
2253 if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
2254 break;
2255
2256 pr_warn("%s: Unknown symbol %s (err %li)\n",
2257 mod->name, name, PTR_ERR(ksym));
2258 ret = PTR_ERR(ksym) ?: -ENOENT;
2259 break;
2260
2261 default:
2262 /* Divert to percpu allocation if a percpu var. */
2263 if (sym[i].st_shndx == info->index.pcpu)
2264 secbase = (unsigned long)mod_percpu(mod);
2265 else
2266 secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
2267 sym[i].st_value += secbase;
2268 break;
2269 }
2270 }
2271
2272 return ret;
2273}
2274
2275static int apply_relocations(struct module *mod, const struct load_info *info)
2276{
2277 unsigned int i;
2278 int err = 0;
2279
2280 /* Now do relocations. */
2281 for (i = 1; i < info->hdr->e_shnum; i++) {
2282 unsigned int infosec = info->sechdrs[i].sh_info;
2283
2284 /* Not a valid relocation section? */
2285 if (infosec >= info->hdr->e_shnum)
2286 continue;
2287
2288 /* Don't bother with non-allocated sections */
2289 if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
2290 continue;
2291
2292 /* Livepatch relocation sections are applied by livepatch */
2293 if (info->sechdrs[i].sh_flags & SHF_RELA_LIVEPATCH)
2294 continue;
2295
2296 if (info->sechdrs[i].sh_type == SHT_REL)
2297 err = apply_relocate(info->sechdrs, info->strtab,
2298 info->index.sym, i, mod);
2299 else if (info->sechdrs[i].sh_type == SHT_RELA)
2300 err = apply_relocate_add(info->sechdrs, info->strtab,
2301 info->index.sym, i, mod);
2302 if (err < 0)
2303 break;
2304 }
2305 return err;
2306}
2307
2308/* Additional bytes needed by arch in front of individual sections */
2309unsigned int __weak arch_mod_section_prepend(struct module *mod,
2310 unsigned int section)
2311{
2312 /* default implementation just returns zero */
2313 return 0;
2314}
2315
2316/* Update size with this section: return offset. */
2317static long get_offset(struct module *mod, unsigned int *size,
2318 Elf_Shdr *sechdr, unsigned int section)
2319{
2320 long ret;
2321
2322 *size += arch_mod_section_prepend(mod, section);
2323 ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
2324 *size = ret + sechdr->sh_size;
2325 return ret;
2326}
2327
2328/* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
2329 might -- code, read-only data, read-write data, small data. Tally
2330 sizes, and place the offsets into sh_entsize fields: high bit means it
2331 belongs in init. */
2332static void layout_sections(struct module *mod, struct load_info *info)
2333{
2334 static unsigned long const masks[][2] = {
2335 /* NOTE: all executable code must be the first section
2336 * in this array; otherwise modify the text_size
2337 * finder in the two loops below */
2338 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
2339 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
2340 { SHF_RO_AFTER_INIT | SHF_ALLOC, ARCH_SHF_SMALL },
2341 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
2342 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
2343 };
2344 unsigned int m, i;
2345
2346 for (i = 0; i < info->hdr->e_shnum; i++)
2347 info->sechdrs[i].sh_entsize = ~0UL;
2348
2349 pr_debug("Core section allocation order:\n");
2350 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2351 for (i = 0; i < info->hdr->e_shnum; ++i) {
2352 Elf_Shdr *s = &info->sechdrs[i];
2353 const char *sname = info->secstrings + s->sh_name;
2354
2355 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2356 || (s->sh_flags & masks[m][1])
2357 || s->sh_entsize != ~0UL
2358 || strstarts(sname, ".init"))
2359 continue;
2360 s->sh_entsize = get_offset(mod, &mod->core_layout.size, s, i);
2361 pr_debug("\t%s\n", sname);
2362 }
2363 switch (m) {
2364 case 0: /* executable */
2365 mod->core_layout.size = debug_align(mod->core_layout.size);
2366 mod->core_layout.text_size = mod->core_layout.size;
2367 break;
2368 case 1: /* RO: text and ro-data */
2369 mod->core_layout.size = debug_align(mod->core_layout.size);
2370 mod->core_layout.ro_size = mod->core_layout.size;
2371 break;
2372 case 2: /* RO after init */
2373 mod->core_layout.size = debug_align(mod->core_layout.size);
2374 mod->core_layout.ro_after_init_size = mod->core_layout.size;
2375 break;
2376 case 4: /* whole core */
2377 mod->core_layout.size = debug_align(mod->core_layout.size);
2378 break;
2379 }
2380 }
2381
2382 pr_debug("Init section allocation order:\n");
2383 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2384 for (i = 0; i < info->hdr->e_shnum; ++i) {
2385 Elf_Shdr *s = &info->sechdrs[i];
2386 const char *sname = info->secstrings + s->sh_name;
2387
2388 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2389 || (s->sh_flags & masks[m][1])
2390 || s->sh_entsize != ~0UL
2391 || !strstarts(sname, ".init"))
2392 continue;
2393 s->sh_entsize = (get_offset(mod, &mod->init_layout.size, s, i)
2394 | INIT_OFFSET_MASK);
2395 pr_debug("\t%s\n", sname);
2396 }
2397 switch (m) {
2398 case 0: /* executable */
2399 mod->init_layout.size = debug_align(mod->init_layout.size);
2400 mod->init_layout.text_size = mod->init_layout.size;
2401 break;
2402 case 1: /* RO: text and ro-data */
2403 mod->init_layout.size = debug_align(mod->init_layout.size);
2404 mod->init_layout.ro_size = mod->init_layout.size;
2405 break;
2406 case 2:
2407 /*
2408 * RO after init doesn't apply to init_layout (only
2409 * core_layout), so it just takes the value of ro_size.
2410 */
2411 mod->init_layout.ro_after_init_size = mod->init_layout.ro_size;
2412 break;
2413 case 4: /* whole init */
2414 mod->init_layout.size = debug_align(mod->init_layout.size);
2415 break;
2416 }
2417 }
2418}
2419
2420static void set_license(struct module *mod, const char *license)
2421{
2422 if (!license)
2423 license = "unspecified";
2424
2425 if (!license_is_gpl_compatible(license)) {
2426 if (!test_taint(TAINT_PROPRIETARY_MODULE))
2427 pr_warn("%s: module license '%s' taints kernel.\n",
2428 mod->name, license);
2429 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2430 LOCKDEP_NOW_UNRELIABLE);
2431 }
2432}
2433
2434/* Parse tag=value strings from .modinfo section */
2435static char *next_string(char *string, unsigned long *secsize)
2436{
2437 /* Skip non-zero chars */
2438 while (string[0]) {
2439 string++;
2440 if ((*secsize)-- <= 1)
2441 return NULL;
2442 }
2443
2444 /* Skip any zero padding. */
2445 while (!string[0]) {
2446 string++;
2447 if ((*secsize)-- <= 1)
2448 return NULL;
2449 }
2450 return string;
2451}
2452
2453static char *get_modinfo(struct load_info *info, const char *tag)
2454{
2455 char *p;
2456 unsigned int taglen = strlen(tag);
2457 Elf_Shdr *infosec = &info->sechdrs[info->index.info];
2458 unsigned long size = infosec->sh_size;
2459
2460 for (p = (char *)infosec->sh_addr; p; p = next_string(p, &size)) {
2461 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
2462 return p + taglen + 1;
2463 }
2464 return NULL;
2465}
2466
2467static void setup_modinfo(struct module *mod, struct load_info *info)
2468{
2469 struct module_attribute *attr;
2470 int i;
2471
2472 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2473 if (attr->setup)
2474 attr->setup(mod, get_modinfo(info, attr->attr.name));
2475 }
2476}
2477
2478static void free_modinfo(struct module *mod)
2479{
2480 struct module_attribute *attr;
2481 int i;
2482
2483 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2484 if (attr->free)
2485 attr->free(mod);
2486 }
2487}
2488
2489#ifdef CONFIG_KALLSYMS
2490
2491/* lookup symbol in given range of kernel_symbols */
2492static const struct kernel_symbol *lookup_symbol(const char *name,
2493 const struct kernel_symbol *start,
2494 const struct kernel_symbol *stop)
2495{
2496 return bsearch(name, start, stop - start,
2497 sizeof(struct kernel_symbol), cmp_name);
2498}
2499
2500static int is_exported(const char *name, unsigned long value,
2501 const struct module *mod)
2502{
2503 const struct kernel_symbol *ks;
2504 if (!mod)
2505 ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
2506 else
2507 ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
2508 return ks != NULL && ks->value == value;
2509}
2510
2511/* As per nm */
2512static char elf_type(const Elf_Sym *sym, const struct load_info *info)
2513{
2514 const Elf_Shdr *sechdrs = info->sechdrs;
2515
2516 if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
2517 if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
2518 return 'v';
2519 else
2520 return 'w';
2521 }
2522 if (sym->st_shndx == SHN_UNDEF)
2523 return 'U';
2524 if (sym->st_shndx == SHN_ABS || sym->st_shndx == info->index.pcpu)
2525 return 'a';
2526 if (sym->st_shndx >= SHN_LORESERVE)
2527 return '?';
2528 if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
2529 return 't';
2530 if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
2531 && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
2532 if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
2533 return 'r';
2534 else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2535 return 'g';
2536 else
2537 return 'd';
2538 }
2539 if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
2540 if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2541 return 's';
2542 else
2543 return 'b';
2544 }
2545 if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
2546 ".debug")) {
2547 return 'n';
2548 }
2549 return '?';
2550}
2551
2552static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
2553 unsigned int shnum, unsigned int pcpundx)
2554{
2555 const Elf_Shdr *sec;
2556
2557 if (src->st_shndx == SHN_UNDEF
2558 || src->st_shndx >= shnum
2559 || !src->st_name)
2560 return false;
2561
2562#ifdef CONFIG_KALLSYMS_ALL
2563 if (src->st_shndx == pcpundx)
2564 return true;
2565#endif
2566
2567 sec = sechdrs + src->st_shndx;
2568 if (!(sec->sh_flags & SHF_ALLOC)
2569#ifndef CONFIG_KALLSYMS_ALL
2570 || !(sec->sh_flags & SHF_EXECINSTR)
2571#endif
2572 || (sec->sh_entsize & INIT_OFFSET_MASK))
2573 return false;
2574
2575 return true;
2576}
2577
2578/*
2579 * We only allocate and copy the strings needed by the parts of symtab
2580 * we keep. This is simple, but has the effect of making multiple
2581 * copies of duplicates. We could be more sophisticated, see
2582 * linux-kernel thread starting with
2583 * <73defb5e4bca04a6431392cc341112b1@localhost>.
2584 */
2585static void layout_symtab(struct module *mod, struct load_info *info)
2586{
2587 Elf_Shdr *symsect = info->sechdrs + info->index.sym;
2588 Elf_Shdr *strsect = info->sechdrs + info->index.str;
2589 const Elf_Sym *src;
2590 unsigned int i, nsrc, ndst, strtab_size = 0;
2591
2592 /* Put symbol section at end of init part of module. */
2593 symsect->sh_flags |= SHF_ALLOC;
2594 symsect->sh_entsize = get_offset(mod, &mod->init_layout.size, symsect,
2595 info->index.sym) | INIT_OFFSET_MASK;
2596 pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
2597
2598 src = (void *)info->hdr + symsect->sh_offset;
2599 nsrc = symsect->sh_size / sizeof(*src);
2600
2601 /* Compute total space required for the core symbols' strtab. */
2602 for (ndst = i = 0; i < nsrc; i++) {
2603 if (i == 0 || is_livepatch_module(mod) ||
2604 is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
2605 info->index.pcpu)) {
2606 strtab_size += strlen(&info->strtab[src[i].st_name])+1;
2607 ndst++;
2608 }
2609 }
2610
2611 /* Append room for core symbols at end of core part. */
2612 info->symoffs = ALIGN(mod->core_layout.size, symsect->sh_addralign ?: 1);
2613 info->stroffs = mod->core_layout.size = info->symoffs + ndst * sizeof(Elf_Sym);
2614 mod->core_layout.size += strtab_size;
2615 mod->core_layout.size = debug_align(mod->core_layout.size);
2616
2617 /* Put string table section at end of init part of module. */
2618 strsect->sh_flags |= SHF_ALLOC;
2619 strsect->sh_entsize = get_offset(mod, &mod->init_layout.size, strsect,
2620 info->index.str) | INIT_OFFSET_MASK;
2621 pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
2622
2623 /* We'll tack temporary mod_kallsyms on the end. */
2624 mod->init_layout.size = ALIGN(mod->init_layout.size,
2625 __alignof__(struct mod_kallsyms));
2626 info->mod_kallsyms_init_off = mod->init_layout.size;
2627 mod->init_layout.size += sizeof(struct mod_kallsyms);
2628 mod->init_layout.size = debug_align(mod->init_layout.size);
2629}
2630
2631/*
2632 * We use the full symtab and strtab which layout_symtab arranged to
2633 * be appended to the init section. Later we switch to the cut-down
2634 * core-only ones.
2635 */
2636static void add_kallsyms(struct module *mod, const struct load_info *info)
2637{
2638 unsigned int i, ndst;
2639 const Elf_Sym *src;
2640 Elf_Sym *dst;
2641 char *s;
2642 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2643
2644 /* Set up to point into init section. */
2645 mod->kallsyms = mod->init_layout.base + info->mod_kallsyms_init_off;
2646
2647 mod->kallsyms->symtab = (void *)symsec->sh_addr;
2648 mod->kallsyms->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
2649 /* Make sure we get permanent strtab: don't use info->strtab. */
2650 mod->kallsyms->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
2651
2652 /* Set types up while we still have access to sections. */
2653 for (i = 0; i < mod->kallsyms->num_symtab; i++)
2654 mod->kallsyms->symtab[i].st_info
2655 = elf_type(&mod->kallsyms->symtab[i], info);
2656
2657 /* Now populate the cut down core kallsyms for after init. */
2658 mod->core_kallsyms.symtab = dst = mod->core_layout.base + info->symoffs;
2659 mod->core_kallsyms.strtab = s = mod->core_layout.base + info->stroffs;
2660 src = mod->kallsyms->symtab;
2661 for (ndst = i = 0; i < mod->kallsyms->num_symtab; i++) {
2662 if (i == 0 || is_livepatch_module(mod) ||
2663 is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
2664 info->index.pcpu)) {
2665 dst[ndst] = src[i];
2666 dst[ndst++].st_name = s - mod->core_kallsyms.strtab;
2667 s += strlcpy(s, &mod->kallsyms->strtab[src[i].st_name],
2668 KSYM_NAME_LEN) + 1;
2669 }
2670 }
2671 mod->core_kallsyms.num_symtab = ndst;
2672}
2673#else
2674static inline void layout_symtab(struct module *mod, struct load_info *info)
2675{
2676}
2677
2678static void add_kallsyms(struct module *mod, const struct load_info *info)
2679{
2680}
2681#endif /* CONFIG_KALLSYMS */
2682
2683static void dynamic_debug_setup(struct _ddebug *debug, unsigned int num)
2684{
2685 if (!debug)
2686 return;
2687#ifdef CONFIG_DYNAMIC_DEBUG
2688 if (ddebug_add_module(debug, num, debug->modname))
2689 pr_err("dynamic debug error adding module: %s\n",
2690 debug->modname);
2691#endif
2692}
2693
2694static void dynamic_debug_remove(struct _ddebug *debug)
2695{
2696 if (debug)
2697 ddebug_remove_module(debug->modname);
2698}
2699
2700void * __weak module_alloc(unsigned long size)
2701{
2702 return vmalloc_exec(size);
2703}
2704
2705#ifdef CONFIG_DEBUG_KMEMLEAK
2706static void kmemleak_load_module(const struct module *mod,
2707 const struct load_info *info)
2708{
2709 unsigned int i;
2710
2711 /* only scan the sections containing data */
2712 kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
2713
2714 for (i = 1; i < info->hdr->e_shnum; i++) {
2715 /* Scan all writable sections that's not executable */
2716 if (!(info->sechdrs[i].sh_flags & SHF_ALLOC) ||
2717 !(info->sechdrs[i].sh_flags & SHF_WRITE) ||
2718 (info->sechdrs[i].sh_flags & SHF_EXECINSTR))
2719 continue;
2720
2721 kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
2722 info->sechdrs[i].sh_size, GFP_KERNEL);
2723 }
2724}
2725#else
2726static inline void kmemleak_load_module(const struct module *mod,
2727 const struct load_info *info)
2728{
2729}
2730#endif
2731
2732#ifdef CONFIG_MODULE_SIG
2733static int module_sig_check(struct load_info *info, int flags)
2734{
2735 int err = -ENOKEY;
2736 const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
2737 const void *mod = info->hdr;
2738
2739 /*
2740 * Require flags == 0, as a module with version information
2741 * removed is no longer the module that was signed
2742 */
2743 if (flags == 0 &&
2744 info->len > markerlen &&
2745 memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
2746 /* We truncate the module to discard the signature */
2747 info->len -= markerlen;
2748 err = mod_verify_sig(mod, &info->len);
2749 }
2750
2751 if (!err) {
2752 info->sig_ok = true;
2753 return 0;
2754 }
2755
2756 /* Not having a signature is only an error if we're strict. */
2757 if (err == -ENOKEY && !sig_enforce)
2758 err = 0;
2759
2760 return err;
2761}
2762#else /* !CONFIG_MODULE_SIG */
2763static int module_sig_check(struct load_info *info, int flags)
2764{
2765 return 0;
2766}
2767#endif /* !CONFIG_MODULE_SIG */
2768
2769/* Sanity checks against invalid binaries, wrong arch, weird elf version. */
2770static int elf_header_check(struct load_info *info)
2771{
2772 if (info->len < sizeof(*(info->hdr)))
2773 return -ENOEXEC;
2774
2775 if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0
2776 || info->hdr->e_type != ET_REL
2777 || !elf_check_arch(info->hdr)
2778 || info->hdr->e_shentsize != sizeof(Elf_Shdr))
2779 return -ENOEXEC;
2780
2781 if (info->hdr->e_shoff >= info->len
2782 || (info->hdr->e_shnum * sizeof(Elf_Shdr) >
2783 info->len - info->hdr->e_shoff))
2784 return -ENOEXEC;
2785
2786 return 0;
2787}
2788
2789#define COPY_CHUNK_SIZE (16*PAGE_SIZE)
2790
2791static int copy_chunked_from_user(void *dst, const void __user *usrc, unsigned long len)
2792{
2793 do {
2794 unsigned long n = min(len, COPY_CHUNK_SIZE);
2795
2796 if (copy_from_user(dst, usrc, n) != 0)
2797 return -EFAULT;
2798 cond_resched();
2799 dst += n;
2800 usrc += n;
2801 len -= n;
2802 } while (len);
2803 return 0;
2804}
2805
2806#ifdef CONFIG_LIVEPATCH
2807static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
2808{
2809 if (get_modinfo(info, "livepatch")) {
2810 mod->klp = true;
2811 add_taint_module(mod, TAINT_LIVEPATCH, LOCKDEP_STILL_OK);
2812 }
2813
2814 return 0;
2815}
2816#else /* !CONFIG_LIVEPATCH */
2817static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
2818{
2819 if (get_modinfo(info, "livepatch")) {
2820 pr_err("%s: module is marked as livepatch module, but livepatch support is disabled",
2821 mod->name);
2822 return -ENOEXEC;
2823 }
2824
2825 return 0;
2826}
2827#endif /* CONFIG_LIVEPATCH */
2828
2829/* Sets info->hdr and info->len. */
2830static int copy_module_from_user(const void __user *umod, unsigned long len,
2831 struct load_info *info)
2832{
2833 int err;
2834
2835 info->len = len;
2836 if (info->len < sizeof(*(info->hdr)))
2837 return -ENOEXEC;
2838
2839 err = security_kernel_read_file(NULL, READING_MODULE);
2840 if (err)
2841 return err;
2842
2843 /* Suck in entire file: we'll want most of it. */
2844 info->hdr = __vmalloc(info->len,
2845 GFP_KERNEL | __GFP_HIGHMEM | __GFP_NOWARN, PAGE_KERNEL);
2846 if (!info->hdr)
2847 return -ENOMEM;
2848
2849 if (copy_chunked_from_user(info->hdr, umod, info->len) != 0) {
2850 vfree(info->hdr);
2851 return -EFAULT;
2852 }
2853
2854 return 0;
2855}
2856
2857static void free_copy(struct load_info *info)
2858{
2859 vfree(info->hdr);
2860}
2861
2862static int rewrite_section_headers(struct load_info *info, int flags)
2863{
2864 unsigned int i;
2865
2866 /* This should always be true, but let's be sure. */
2867 info->sechdrs[0].sh_addr = 0;
2868
2869 for (i = 1; i < info->hdr->e_shnum; i++) {
2870 Elf_Shdr *shdr = &info->sechdrs[i];
2871 if (shdr->sh_type != SHT_NOBITS
2872 && info->len < shdr->sh_offset + shdr->sh_size) {
2873 pr_err("Module len %lu truncated\n", info->len);
2874 return -ENOEXEC;
2875 }
2876
2877 /* Mark all sections sh_addr with their address in the
2878 temporary image. */
2879 shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
2880
2881#ifndef CONFIG_MODULE_UNLOAD
2882 /* Don't load .exit sections */
2883 if (strstarts(info->secstrings+shdr->sh_name, ".exit"))
2884 shdr->sh_flags &= ~(unsigned long)SHF_ALLOC;
2885#endif
2886 }
2887
2888 /* Track but don't keep modinfo and version sections. */
2889 if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
2890 info->index.vers = 0; /* Pretend no __versions section! */
2891 else
2892 info->index.vers = find_sec(info, "__versions");
2893 info->index.info = find_sec(info, ".modinfo");
2894 info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
2895 info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
2896 return 0;
2897}
2898
2899/*
2900 * Set up our basic convenience variables (pointers to section headers,
2901 * search for module section index etc), and do some basic section
2902 * verification.
2903 *
2904 * Return the temporary module pointer (we'll replace it with the final
2905 * one when we move the module sections around).
2906 */
2907static struct module *setup_load_info(struct load_info *info, int flags)
2908{
2909 unsigned int i;
2910 int err;
2911 struct module *mod;
2912
2913 /* Set up the convenience variables */
2914 info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
2915 info->secstrings = (void *)info->hdr
2916 + info->sechdrs[info->hdr->e_shstrndx].sh_offset;
2917
2918 err = rewrite_section_headers(info, flags);
2919 if (err)
2920 return ERR_PTR(err);
2921
2922 /* Find internal symbols and strings. */
2923 for (i = 1; i < info->hdr->e_shnum; i++) {
2924 if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
2925 info->index.sym = i;
2926 info->index.str = info->sechdrs[i].sh_link;
2927 info->strtab = (char *)info->hdr
2928 + info->sechdrs[info->index.str].sh_offset;
2929 break;
2930 }
2931 }
2932
2933 info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
2934 if (!info->index.mod) {
2935 pr_warn("No module found in object\n");
2936 return ERR_PTR(-ENOEXEC);
2937 }
2938 /* This is temporary: point mod into copy of data. */
2939 mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2940
2941 if (info->index.sym == 0) {
2942 pr_warn("%s: module has no symbols (stripped?)\n", mod->name);
2943 return ERR_PTR(-ENOEXEC);
2944 }
2945
2946 info->index.pcpu = find_pcpusec(info);
2947
2948 /* Check module struct version now, before we try to use module. */
2949 if (!check_modstruct_version(info->sechdrs, info->index.vers, mod))
2950 return ERR_PTR(-ENOEXEC);
2951
2952 return mod;
2953}
2954
2955static int check_modinfo(struct module *mod, struct load_info *info, int flags)
2956{
2957 const char *modmagic = get_modinfo(info, "vermagic");
2958 int err;
2959
2960 if (flags & MODULE_INIT_IGNORE_VERMAGIC)
2961 modmagic = NULL;
2962
2963 /* This is allowed: modprobe --force will invalidate it. */
2964 if (!modmagic) {
2965 err = try_to_force_load(mod, "bad vermagic");
2966 if (err)
2967 return err;
2968 } else if (!same_magic(modmagic, vermagic, info->index.vers)) {
2969 pr_err("%s: version magic '%s' should be '%s'\n",
2970 mod->name, modmagic, vermagic);
2971 return -ENOEXEC;
2972 }
2973
2974 if (!get_modinfo(info, "intree")) {
2975 if (!test_taint(TAINT_OOT_MODULE))
2976 pr_warn("%s: loading out-of-tree module taints kernel.\n",
2977 mod->name);
2978 add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
2979 }
2980
2981 if (get_modinfo(info, "staging")) {
2982 add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
2983 pr_warn("%s: module is from the staging directory, the quality "
2984 "is unknown, you have been warned.\n", mod->name);
2985 }
2986
2987 err = check_modinfo_livepatch(mod, info);
2988 if (err)
2989 return err;
2990
2991 /* Set up license info based on the info section */
2992 set_license(mod, get_modinfo(info, "license"));
2993
2994 return 0;
2995}
2996
2997static int find_module_sections(struct module *mod, struct load_info *info)
2998{
2999 mod->kp = section_objs(info, "__param",
3000 sizeof(*mod->kp), &mod->num_kp);
3001 mod->syms = section_objs(info, "__ksymtab",
3002 sizeof(*mod->syms), &mod->num_syms);
3003 mod->crcs = section_addr(info, "__kcrctab");
3004 mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
3005 sizeof(*mod->gpl_syms),
3006 &mod->num_gpl_syms);
3007 mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
3008 mod->gpl_future_syms = section_objs(info,
3009 "__ksymtab_gpl_future",
3010 sizeof(*mod->gpl_future_syms),
3011 &mod->num_gpl_future_syms);
3012 mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future");
3013
3014#ifdef CONFIG_UNUSED_SYMBOLS
3015 mod->unused_syms = section_objs(info, "__ksymtab_unused",
3016 sizeof(*mod->unused_syms),
3017 &mod->num_unused_syms);
3018 mod->unused_crcs = section_addr(info, "__kcrctab_unused");
3019 mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl",
3020 sizeof(*mod->unused_gpl_syms),
3021 &mod->num_unused_gpl_syms);
3022 mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl");
3023#endif
3024#ifdef CONFIG_CONSTRUCTORS
3025 mod->ctors = section_objs(info, ".ctors",
3026 sizeof(*mod->ctors), &mod->num_ctors);
3027 if (!mod->ctors)
3028 mod->ctors = section_objs(info, ".init_array",
3029 sizeof(*mod->ctors), &mod->num_ctors);
3030 else if (find_sec(info, ".init_array")) {
3031 /*
3032 * This shouldn't happen with same compiler and binutils
3033 * building all parts of the module.
3034 */
3035 pr_warn("%s: has both .ctors and .init_array.\n",
3036 mod->name);
3037 return -EINVAL;
3038 }
3039#endif
3040
3041#ifdef CONFIG_TRACEPOINTS
3042 mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
3043 sizeof(*mod->tracepoints_ptrs),
3044 &mod->num_tracepoints);
3045#endif
3046#ifdef HAVE_JUMP_LABEL
3047 mod->jump_entries = section_objs(info, "__jump_table",
3048 sizeof(*mod->jump_entries),
3049 &mod->num_jump_entries);
3050#endif
3051#ifdef CONFIG_EVENT_TRACING
3052 mod->trace_events = section_objs(info, "_ftrace_events",
3053 sizeof(*mod->trace_events),
3054 &mod->num_trace_events);
3055 mod->trace_enums = section_objs(info, "_ftrace_enum_map",
3056 sizeof(*mod->trace_enums),
3057 &mod->num_trace_enums);
3058#endif
3059#ifdef CONFIG_TRACING
3060 mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
3061 sizeof(*mod->trace_bprintk_fmt_start),
3062 &mod->num_trace_bprintk_fmt);
3063#endif
3064#ifdef CONFIG_FTRACE_MCOUNT_RECORD
3065 /* sechdrs[0].sh_size is always zero */
3066 mod->ftrace_callsites = section_objs(info, "__mcount_loc",
3067 sizeof(*mod->ftrace_callsites),
3068 &mod->num_ftrace_callsites);
3069#endif
3070
3071 mod->extable = section_objs(info, "__ex_table",
3072 sizeof(*mod->extable), &mod->num_exentries);
3073
3074 if (section_addr(info, "__obsparm"))
3075 pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
3076
3077 info->debug = section_objs(info, "__verbose",
3078 sizeof(*info->debug), &info->num_debug);
3079
3080 return 0;
3081}
3082
3083static int move_module(struct module *mod, struct load_info *info)
3084{
3085 int i;
3086 void *ptr;
3087
3088 /* Do the allocs. */
3089 ptr = module_alloc(mod->core_layout.size);
3090 /*
3091 * The pointer to this block is stored in the module structure
3092 * which is inside the block. Just mark it as not being a
3093 * leak.
3094 */
3095 kmemleak_not_leak(ptr);
3096 if (!ptr)
3097 return -ENOMEM;
3098
3099 memset(ptr, 0, mod->core_layout.size);
3100 mod->core_layout.base = ptr;
3101
3102 if (mod->init_layout.size) {
3103 ptr = module_alloc(mod->init_layout.size);
3104 /*
3105 * The pointer to this block is stored in the module structure
3106 * which is inside the block. This block doesn't need to be
3107 * scanned as it contains data and code that will be freed
3108 * after the module is initialized.
3109 */
3110 kmemleak_ignore(ptr);
3111 if (!ptr) {
3112 module_memfree(mod->core_layout.base);
3113 return -ENOMEM;
3114 }
3115 memset(ptr, 0, mod->init_layout.size);
3116 mod->init_layout.base = ptr;
3117 } else
3118 mod->init_layout.base = NULL;
3119
3120 /* Transfer each section which specifies SHF_ALLOC */
3121 pr_debug("final section addresses:\n");
3122 for (i = 0; i < info->hdr->e_shnum; i++) {
3123 void *dest;
3124 Elf_Shdr *shdr = &info->sechdrs[i];
3125
3126 if (!(shdr->sh_flags & SHF_ALLOC))
3127 continue;
3128
3129 if (shdr->sh_entsize & INIT_OFFSET_MASK)
3130 dest = mod->init_layout.base
3131 + (shdr->sh_entsize & ~INIT_OFFSET_MASK);
3132 else
3133 dest = mod->core_layout.base + shdr->sh_entsize;
3134
3135 if (shdr->sh_type != SHT_NOBITS)
3136 memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
3137 /* Update sh_addr to point to copy in image. */
3138 shdr->sh_addr = (unsigned long)dest;
3139 pr_debug("\t0x%lx %s\n",
3140 (long)shdr->sh_addr, info->secstrings + shdr->sh_name);
3141 }
3142
3143 return 0;
3144}
3145
3146static int check_module_license_and_versions(struct module *mod)
3147{
3148 int prev_taint = test_taint(TAINT_PROPRIETARY_MODULE);
3149
3150 /*
3151 * ndiswrapper is under GPL by itself, but loads proprietary modules.
3152 * Don't use add_taint_module(), as it would prevent ndiswrapper from
3153 * using GPL-only symbols it needs.
3154 */
3155 if (strcmp(mod->name, "ndiswrapper") == 0)
3156 add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
3157
3158 /* driverloader was caught wrongly pretending to be under GPL */
3159 if (strcmp(mod->name, "driverloader") == 0)
3160 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3161 LOCKDEP_NOW_UNRELIABLE);
3162
3163 /* lve claims to be GPL but upstream won't provide source */
3164 if (strcmp(mod->name, "lve") == 0)
3165 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3166 LOCKDEP_NOW_UNRELIABLE);
3167
3168 if (!prev_taint && test_taint(TAINT_PROPRIETARY_MODULE))
3169 pr_warn("%s: module license taints kernel.\n", mod->name);
3170
3171#ifdef CONFIG_MODVERSIONS
3172 if ((mod->num_syms && !mod->crcs)
3173 || (mod->num_gpl_syms && !mod->gpl_crcs)
3174 || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
3175#ifdef CONFIG_UNUSED_SYMBOLS
3176 || (mod->num_unused_syms && !mod->unused_crcs)
3177 || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
3178#endif
3179 ) {
3180 return try_to_force_load(mod,
3181 "no versions for exported symbols");
3182 }
3183#endif
3184 return 0;
3185}
3186
3187static void flush_module_icache(const struct module *mod)
3188{
3189 mm_segment_t old_fs;
3190
3191 /* flush the icache in correct context */
3192 old_fs = get_fs();
3193 set_fs(KERNEL_DS);
3194
3195 /*
3196 * Flush the instruction cache, since we've played with text.
3197 * Do it before processing of module parameters, so the module
3198 * can provide parameter accessor functions of its own.
3199 */
3200 if (mod->init_layout.base)
3201 flush_icache_range((unsigned long)mod->init_layout.base,
3202 (unsigned long)mod->init_layout.base
3203 + mod->init_layout.size);
3204 flush_icache_range((unsigned long)mod->core_layout.base,
3205 (unsigned long)mod->core_layout.base + mod->core_layout.size);
3206
3207 set_fs(old_fs);
3208}
3209
3210int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
3211 Elf_Shdr *sechdrs,
3212 char *secstrings,
3213 struct module *mod)
3214{
3215 return 0;
3216}
3217
3218/* module_blacklist is a comma-separated list of module names */
3219static char *module_blacklist;
3220static bool blacklisted(char *module_name)
3221{
3222 const char *p;
3223 size_t len;
3224
3225 if (!module_blacklist)
3226 return false;
3227
3228 for (p = module_blacklist; *p; p += len) {
3229 len = strcspn(p, ",");
3230 if (strlen(module_name) == len && !memcmp(module_name, p, len))
3231 return true;
3232 if (p[len] == ',')
3233 len++;
3234 }
3235 return false;
3236}
3237core_param(module_blacklist, module_blacklist, charp, 0400);
3238
3239static struct module *layout_and_allocate(struct load_info *info, int flags)
3240{
3241 /* Module within temporary copy. */
3242 struct module *mod;
3243 unsigned int ndx;
3244 int err;
3245
3246 mod = setup_load_info(info, flags);
3247 if (IS_ERR(mod))
3248 return mod;
3249
3250 if (blacklisted(mod->name))
3251 return ERR_PTR(-EPERM);
3252
3253 err = check_modinfo(mod, info, flags);
3254 if (err)
3255 return ERR_PTR(err);
3256
3257 /* Allow arches to frob section contents and sizes. */
3258 err = module_frob_arch_sections(info->hdr, info->sechdrs,
3259 info->secstrings, mod);
3260 if (err < 0)
3261 return ERR_PTR(err);
3262
3263 /* We will do a special allocation for per-cpu sections later. */
3264 info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC;
3265
3266 /*
3267 * Mark ro_after_init section with SHF_RO_AFTER_INIT so that
3268 * layout_sections() can put it in the right place.
3269 * Note: ro_after_init sections also have SHF_{WRITE,ALLOC} set.
3270 */
3271 ndx = find_sec(info, ".data..ro_after_init");
3272 if (ndx)
3273 info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT;
3274
3275 /* Determine total sizes, and put offsets in sh_entsize. For now
3276 this is done generically; there doesn't appear to be any
3277 special cases for the architectures. */
3278 layout_sections(mod, info);
3279 layout_symtab(mod, info);
3280
3281 /* Allocate and move to the final place */
3282 err = move_module(mod, info);
3283 if (err)
3284 return ERR_PTR(err);
3285
3286 /* Module has been copied to its final place now: return it. */
3287 mod = (void *)info->sechdrs[info->index.mod].sh_addr;
3288 kmemleak_load_module(mod, info);
3289 return mod;
3290}
3291
3292/* mod is no longer valid after this! */
3293static void module_deallocate(struct module *mod, struct load_info *info)
3294{
3295 percpu_modfree(mod);
3296 module_arch_freeing_init(mod);
3297 module_memfree(mod->init_layout.base);
3298 module_memfree(mod->core_layout.base);
3299}
3300
3301int __weak module_finalize(const Elf_Ehdr *hdr,
3302 const Elf_Shdr *sechdrs,
3303 struct module *me)
3304{
3305 return 0;
3306}
3307
3308static int post_relocation(struct module *mod, const struct load_info *info)
3309{
3310 /* Sort exception table now relocations are done. */
3311 sort_extable(mod->extable, mod->extable + mod->num_exentries);
3312
3313 /* Copy relocated percpu area over. */
3314 percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
3315 info->sechdrs[info->index.pcpu].sh_size);
3316
3317 /* Setup kallsyms-specific fields. */
3318 add_kallsyms(mod, info);
3319
3320 /* Arch-specific module finalizing. */
3321 return module_finalize(info->hdr, info->sechdrs, mod);
3322}
3323
3324/* Is this module of this name done loading? No locks held. */
3325static bool finished_loading(const char *name)
3326{
3327 struct module *mod;
3328 bool ret;
3329
3330 /*
3331 * The module_mutex should not be a heavily contended lock;
3332 * if we get the occasional sleep here, we'll go an extra iteration
3333 * in the wait_event_interruptible(), which is harmless.
3334 */
3335 sched_annotate_sleep();
3336 mutex_lock(&module_mutex);
3337 mod = find_module_all(name, strlen(name), true);
3338 ret = !mod || mod->state == MODULE_STATE_LIVE
3339 || mod->state == MODULE_STATE_GOING;
3340 mutex_unlock(&module_mutex);
3341
3342 return ret;
3343}
3344
3345/* Call module constructors. */
3346static void do_mod_ctors(struct module *mod)
3347{
3348#ifdef CONFIG_CONSTRUCTORS
3349 unsigned long i;
3350
3351 for (i = 0; i < mod->num_ctors; i++)
3352 mod->ctors[i]();
3353#endif
3354}
3355
3356/* For freeing module_init on success, in case kallsyms traversing */
3357struct mod_initfree {
3358 struct rcu_head rcu;
3359 void *module_init;
3360};
3361
3362static void do_free_init(struct rcu_head *head)
3363{
3364 struct mod_initfree *m = container_of(head, struct mod_initfree, rcu);
3365 module_memfree(m->module_init);
3366 kfree(m);
3367}
3368
3369/*
3370 * This is where the real work happens.
3371 *
3372 * Keep it uninlined to provide a reliable breakpoint target, e.g. for the gdb
3373 * helper command 'lx-symbols'.
3374 */
3375static noinline int do_init_module(struct module *mod)
3376{
3377 int ret = 0;
3378 struct mod_initfree *freeinit;
3379
3380 freeinit = kmalloc(sizeof(*freeinit), GFP_KERNEL);
3381 if (!freeinit) {
3382 ret = -ENOMEM;
3383 goto fail;
3384 }
3385 freeinit->module_init = mod->init_layout.base;
3386
3387 /*
3388 * We want to find out whether @mod uses async during init. Clear
3389 * PF_USED_ASYNC. async_schedule*() will set it.
3390 */
3391 current->flags &= ~PF_USED_ASYNC;
3392
3393 do_mod_ctors(mod);
3394 /* Start the module */
3395 if (mod->init != NULL)
3396 ret = do_one_initcall(mod->init);
3397 if (ret < 0) {
3398 goto fail_free_freeinit;
3399 }
3400 if (ret > 0) {
3401 pr_warn("%s: '%s'->init suspiciously returned %d, it should "
3402 "follow 0/-E convention\n"
3403 "%s: loading module anyway...\n",
3404 __func__, mod->name, ret, __func__);
3405 dump_stack();
3406 }
3407
3408 /* Now it's a first class citizen! */
3409 mod->state = MODULE_STATE_LIVE;
3410 blocking_notifier_call_chain(&module_notify_list,
3411 MODULE_STATE_LIVE, mod);
3412
3413 /*
3414 * We need to finish all async code before the module init sequence
3415 * is done. This has potential to deadlock. For example, a newly
3416 * detected block device can trigger request_module() of the
3417 * default iosched from async probing task. Once userland helper
3418 * reaches here, async_synchronize_full() will wait on the async
3419 * task waiting on request_module() and deadlock.
3420 *
3421 * This deadlock is avoided by perfomring async_synchronize_full()
3422 * iff module init queued any async jobs. This isn't a full
3423 * solution as it will deadlock the same if module loading from
3424 * async jobs nests more than once; however, due to the various
3425 * constraints, this hack seems to be the best option for now.
3426 * Please refer to the following thread for details.
3427 *
3428 * http://thread.gmane.org/gmane.linux.kernel/1420814
3429 */
3430 if (!mod->async_probe_requested && (current->flags & PF_USED_ASYNC))
3431 async_synchronize_full();
3432
3433 mutex_lock(&module_mutex);
3434 /* Drop initial reference. */
3435 module_put(mod);
3436 trim_init_extable(mod);
3437#ifdef CONFIG_KALLSYMS
3438 /* Switch to core kallsyms now init is done: kallsyms may be walking! */
3439 rcu_assign_pointer(mod->kallsyms, &mod->core_kallsyms);
3440#endif
3441 module_enable_ro(mod, true);
3442 mod_tree_remove_init(mod);
3443 disable_ro_nx(&mod->init_layout);
3444 module_arch_freeing_init(mod);
3445 mod->init_layout.base = NULL;
3446 mod->init_layout.size = 0;
3447 mod->init_layout.ro_size = 0;
3448 mod->init_layout.ro_after_init_size = 0;
3449 mod->init_layout.text_size = 0;
3450 /*
3451 * We want to free module_init, but be aware that kallsyms may be
3452 * walking this with preempt disabled. In all the failure paths, we
3453 * call synchronize_sched(), but we don't want to slow down the success
3454 * path, so use actual RCU here.
3455 */
3456 call_rcu_sched(&freeinit->rcu, do_free_init);
3457 mutex_unlock(&module_mutex);
3458 wake_up_all(&module_wq);
3459
3460 return 0;
3461
3462fail_free_freeinit:
3463 kfree(freeinit);
3464fail:
3465 /* Try to protect us from buggy refcounters. */
3466 mod->state = MODULE_STATE_GOING;
3467 synchronize_sched();
3468 module_put(mod);
3469 blocking_notifier_call_chain(&module_notify_list,
3470 MODULE_STATE_GOING, mod);
3471 klp_module_going(mod);
3472 ftrace_release_mod(mod);
3473 free_module(mod);
3474 wake_up_all(&module_wq);
3475 return ret;
3476}
3477
3478static int may_init_module(void)
3479{
3480 if (!capable(CAP_SYS_MODULE) || modules_disabled)
3481 return -EPERM;
3482
3483 return 0;
3484}
3485
3486/*
3487 * We try to place it in the list now to make sure it's unique before
3488 * we dedicate too many resources. In particular, temporary percpu
3489 * memory exhaustion.
3490 */
3491static int add_unformed_module(struct module *mod)
3492{
3493 int err;
3494 struct module *old;
3495
3496 mod->state = MODULE_STATE_UNFORMED;
3497
3498again:
3499 mutex_lock(&module_mutex);
3500 old = find_module_all(mod->name, strlen(mod->name), true);
3501 if (old != NULL) {
3502 if (old->state == MODULE_STATE_COMING
3503 || old->state == MODULE_STATE_UNFORMED) {
3504 /* Wait in case it fails to load. */
3505 mutex_unlock(&module_mutex);
3506 err = wait_event_interruptible(module_wq,
3507 finished_loading(mod->name));
3508 if (err)
3509 goto out_unlocked;
3510 goto again;
3511 }
3512 err = -EEXIST;
3513 goto out;
3514 }
3515 mod_update_bounds(mod);
3516 list_add_rcu(&mod->list, &modules);
3517 mod_tree_insert(mod);
3518 err = 0;
3519
3520out:
3521 mutex_unlock(&module_mutex);
3522out_unlocked:
3523 return err;
3524}
3525
3526static int complete_formation(struct module *mod, struct load_info *info)
3527{
3528 int err;
3529
3530 mutex_lock(&module_mutex);
3531
3532 /* Find duplicate symbols (must be called under lock). */
3533 err = verify_export_symbols(mod);
3534 if (err < 0)
3535 goto out;
3536
3537 /* This relies on module_mutex for list integrity. */
3538 module_bug_finalize(info->hdr, info->sechdrs, mod);
3539
3540 module_enable_ro(mod, false);
3541 module_enable_nx(mod);
3542
3543 /* Mark state as coming so strong_try_module_get() ignores us,
3544 * but kallsyms etc. can see us. */
3545 mod->state = MODULE_STATE_COMING;
3546 mutex_unlock(&module_mutex);
3547
3548 return 0;
3549
3550out:
3551 mutex_unlock(&module_mutex);
3552 return err;
3553}
3554
3555static int prepare_coming_module(struct module *mod)
3556{
3557 int err;
3558
3559 ftrace_module_enable(mod);
3560 err = klp_module_coming(mod);
3561 if (err)
3562 return err;
3563
3564 blocking_notifier_call_chain(&module_notify_list,
3565 MODULE_STATE_COMING, mod);
3566 return 0;
3567}
3568
3569static int unknown_module_param_cb(char *param, char *val, const char *modname,
3570 void *arg)
3571{
3572 struct module *mod = arg;
3573 int ret;
3574
3575 if (strcmp(param, "async_probe") == 0) {
3576 mod->async_probe_requested = true;
3577 return 0;
3578 }
3579
3580 /* Check for magic 'dyndbg' arg */
3581 ret = ddebug_dyndbg_module_param_cb(param, val, modname);
3582 if (ret != 0)
3583 pr_warn("%s: unknown parameter '%s' ignored\n", modname, param);
3584 return 0;
3585}
3586
3587/* Allocate and load the module: note that size of section 0 is always
3588 zero, and we rely on this for optional sections. */
3589static int load_module(struct load_info *info, const char __user *uargs,
3590 int flags)
3591{
3592 struct module *mod;
3593 long err;
3594 char *after_dashes;
3595
3596 err = module_sig_check(info, flags);
3597 if (err)
3598 goto free_copy;
3599
3600 err = elf_header_check(info);
3601 if (err)
3602 goto free_copy;
3603
3604 /* Figure out module layout, and allocate all the memory. */
3605 mod = layout_and_allocate(info, flags);
3606 if (IS_ERR(mod)) {
3607 err = PTR_ERR(mod);
3608 goto free_copy;
3609 }
3610
3611 /* Reserve our place in the list. */
3612 err = add_unformed_module(mod);
3613 if (err)
3614 goto free_module;
3615
3616#ifdef CONFIG_MODULE_SIG
3617 mod->sig_ok = info->sig_ok;
3618 if (!mod->sig_ok) {
3619 pr_notice_once("%s: module verification failed: signature "
3620 "and/or required key missing - tainting "
3621 "kernel\n", mod->name);
3622 add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK);
3623 }
3624#endif
3625
3626 /* To avoid stressing percpu allocator, do this once we're unique. */
3627 err = percpu_modalloc(mod, info);
3628 if (err)
3629 goto unlink_mod;
3630
3631 /* Now module is in final location, initialize linked lists, etc. */
3632 err = module_unload_init(mod);
3633 if (err)
3634 goto unlink_mod;
3635
3636 init_param_lock(mod);
3637
3638 /* Now we've got everything in the final locations, we can
3639 * find optional sections. */
3640 err = find_module_sections(mod, info);
3641 if (err)
3642 goto free_unload;
3643
3644 err = check_module_license_and_versions(mod);
3645 if (err)
3646 goto free_unload;
3647
3648 /* Set up MODINFO_ATTR fields */
3649 setup_modinfo(mod, info);
3650
3651 /* Fix up syms, so that st_value is a pointer to location. */
3652 err = simplify_symbols(mod, info);
3653 if (err < 0)
3654 goto free_modinfo;
3655
3656 err = apply_relocations(mod, info);
3657 if (err < 0)
3658 goto free_modinfo;
3659
3660 err = post_relocation(mod, info);
3661 if (err < 0)
3662 goto free_modinfo;
3663
3664 flush_module_icache(mod);
3665
3666 /* Now copy in args */
3667 mod->args = strndup_user(uargs, ~0UL >> 1);
3668 if (IS_ERR(mod->args)) {
3669 err = PTR_ERR(mod->args);
3670 goto free_arch_cleanup;
3671 }
3672
3673 dynamic_debug_setup(info->debug, info->num_debug);
3674
3675 /* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
3676 ftrace_module_init(mod);
3677
3678 /* Finally it's fully formed, ready to start executing. */
3679 err = complete_formation(mod, info);
3680 if (err)
3681 goto ddebug_cleanup;
3682
3683 err = prepare_coming_module(mod);
3684 if (err)
3685 goto bug_cleanup;
3686
3687 /* Module is ready to execute: parsing args may do that. */
3688 after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
3689 -32768, 32767, mod,
3690 unknown_module_param_cb);
3691 if (IS_ERR(after_dashes)) {
3692 err = PTR_ERR(after_dashes);
3693 goto coming_cleanup;
3694 } else if (after_dashes) {
3695 pr_warn("%s: parameters '%s' after `--' ignored\n",
3696 mod->name, after_dashes);
3697 }
3698
3699 /* Link in to syfs. */
3700 err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
3701 if (err < 0)
3702 goto coming_cleanup;
3703
3704 if (is_livepatch_module(mod)) {
3705 err = copy_module_elf(mod, info);
3706 if (err < 0)
3707 goto sysfs_cleanup;
3708 }
3709
3710 /* Get rid of temporary copy. */
3711 free_copy(info);
3712
3713 /* Done! */
3714 trace_module_load(mod);
3715
3716 return do_init_module(mod);
3717
3718 sysfs_cleanup:
3719 mod_sysfs_teardown(mod);
3720 coming_cleanup:
3721 mod->state = MODULE_STATE_GOING;
3722 destroy_params(mod->kp, mod->num_kp);
3723 blocking_notifier_call_chain(&module_notify_list,
3724 MODULE_STATE_GOING, mod);
3725 klp_module_going(mod);
3726 bug_cleanup:
3727 /* module_bug_cleanup needs module_mutex protection */
3728 mutex_lock(&module_mutex);
3729 module_bug_cleanup(mod);
3730 mutex_unlock(&module_mutex);
3731
3732 /* we can't deallocate the module until we clear memory protection */
3733 module_disable_ro(mod);
3734 module_disable_nx(mod);
3735
3736 ddebug_cleanup:
3737 dynamic_debug_remove(info->debug);
3738 synchronize_sched();
3739 kfree(mod->args);
3740 free_arch_cleanup:
3741 module_arch_cleanup(mod);
3742 free_modinfo:
3743 free_modinfo(mod);
3744 free_unload:
3745 module_unload_free(mod);
3746 unlink_mod:
3747 mutex_lock(&module_mutex);
3748 /* Unlink carefully: kallsyms could be walking list. */
3749 list_del_rcu(&mod->list);
3750 mod_tree_remove(mod);
3751 wake_up_all(&module_wq);
3752 /* Wait for RCU-sched synchronizing before releasing mod->list. */
3753 synchronize_sched();
3754 mutex_unlock(&module_mutex);
3755 free_module:
3756 /*
3757 * Ftrace needs to clean up what it initialized.
3758 * This does nothing if ftrace_module_init() wasn't called,
3759 * but it must be called outside of module_mutex.
3760 */
3761 ftrace_release_mod(mod);
3762 /* Free lock-classes; relies on the preceding sync_rcu() */
3763 lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
3764
3765 module_deallocate(mod, info);
3766 free_copy:
3767 free_copy(info);
3768 return err;
3769}
3770
3771SYSCALL_DEFINE3(init_module, void __user *, umod,
3772 unsigned long, len, const char __user *, uargs)
3773{
3774 int err;
3775 struct load_info info = { };
3776
3777 err = may_init_module();
3778 if (err)
3779 return err;
3780
3781 pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
3782 umod, len, uargs);
3783
3784 err = copy_module_from_user(umod, len, &info);
3785 if (err)
3786 return err;
3787
3788 return load_module(&info, uargs, 0);
3789}
3790
3791SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
3792{
3793 struct load_info info = { };
3794 loff_t size;
3795 void *hdr;
3796 int err;
3797
3798 err = may_init_module();
3799 if (err)
3800 return err;
3801
3802 pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags);
3803
3804 if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS
3805 |MODULE_INIT_IGNORE_VERMAGIC))
3806 return -EINVAL;
3807
3808 err = kernel_read_file_from_fd(fd, &hdr, &size, INT_MAX,
3809 READING_MODULE);
3810 if (err)
3811 return err;
3812 info.hdr = hdr;
3813 info.len = size;
3814
3815 return load_module(&info, uargs, flags);
3816}
3817
3818static inline int within(unsigned long addr, void *start, unsigned long size)
3819{
3820 return ((void *)addr >= start && (void *)addr < start + size);
3821}
3822
3823#ifdef CONFIG_KALLSYMS
3824/*
3825 * This ignores the intensely annoying "mapping symbols" found
3826 * in ARM ELF files: $a, $t and $d.
3827 */
3828static inline int is_arm_mapping_symbol(const char *str)
3829{
3830 if (str[0] == '.' && str[1] == 'L')
3831 return true;
3832 return str[0] == '$' && strchr("axtd", str[1])
3833 && (str[2] == '\0' || str[2] == '.');
3834}
3835
3836static const char *symname(struct mod_kallsyms *kallsyms, unsigned int symnum)
3837{
3838 return kallsyms->strtab + kallsyms->symtab[symnum].st_name;
3839}
3840
3841static const char *get_ksymbol(struct module *mod,
3842 unsigned long addr,
3843 unsigned long *size,
3844 unsigned long *offset)
3845{
3846 unsigned int i, best = 0;
3847 unsigned long nextval;
3848 struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
3849
3850 /* At worse, next value is at end of module */
3851 if (within_module_init(addr, mod))
3852 nextval = (unsigned long)mod->init_layout.base+mod->init_layout.text_size;
3853 else
3854 nextval = (unsigned long)mod->core_layout.base+mod->core_layout.text_size;
3855
3856 /* Scan for closest preceding symbol, and next symbol. (ELF
3857 starts real symbols at 1). */
3858 for (i = 1; i < kallsyms->num_symtab; i++) {
3859 if (kallsyms->symtab[i].st_shndx == SHN_UNDEF)
3860 continue;
3861
3862 /* We ignore unnamed symbols: they're uninformative
3863 * and inserted at a whim. */
3864 if (*symname(kallsyms, i) == '\0'
3865 || is_arm_mapping_symbol(symname(kallsyms, i)))
3866 continue;
3867
3868 if (kallsyms->symtab[i].st_value <= addr
3869 && kallsyms->symtab[i].st_value > kallsyms->symtab[best].st_value)
3870 best = i;
3871 if (kallsyms->symtab[i].st_value > addr
3872 && kallsyms->symtab[i].st_value < nextval)
3873 nextval = kallsyms->symtab[i].st_value;
3874 }
3875
3876 if (!best)
3877 return NULL;
3878
3879 if (size)
3880 *size = nextval - kallsyms->symtab[best].st_value;
3881 if (offset)
3882 *offset = addr - kallsyms->symtab[best].st_value;
3883 return symname(kallsyms, best);
3884}
3885
3886/* For kallsyms to ask for address resolution. NULL means not found. Careful
3887 * not to lock to avoid deadlock on oopses, simply disable preemption. */
3888const char *module_address_lookup(unsigned long addr,
3889 unsigned long *size,
3890 unsigned long *offset,
3891 char **modname,
3892 char *namebuf)
3893{
3894 const char *ret = NULL;
3895 struct module *mod;
3896
3897 preempt_disable();
3898 mod = __module_address(addr);
3899 if (mod) {
3900 if (modname)
3901 *modname = mod->name;
3902 ret = get_ksymbol(mod, addr, size, offset);
3903 }
3904 /* Make a copy in here where it's safe */
3905 if (ret) {
3906 strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
3907 ret = namebuf;
3908 }
3909 preempt_enable();
3910
3911 return ret;
3912}
3913
3914int lookup_module_symbol_name(unsigned long addr, char *symname)
3915{
3916 struct module *mod;
3917
3918 preempt_disable();
3919 list_for_each_entry_rcu(mod, &modules, list) {
3920 if (mod->state == MODULE_STATE_UNFORMED)
3921 continue;
3922 if (within_module(addr, mod)) {
3923 const char *sym;
3924
3925 sym = get_ksymbol(mod, addr, NULL, NULL);
3926 if (!sym)
3927 goto out;
3928 strlcpy(symname, sym, KSYM_NAME_LEN);
3929 preempt_enable();
3930 return 0;
3931 }
3932 }
3933out:
3934 preempt_enable();
3935 return -ERANGE;
3936}
3937
3938int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
3939 unsigned long *offset, char *modname, char *name)
3940{
3941 struct module *mod;
3942
3943 preempt_disable();
3944 list_for_each_entry_rcu(mod, &modules, list) {
3945 if (mod->state == MODULE_STATE_UNFORMED)
3946 continue;
3947 if (within_module(addr, mod)) {
3948 const char *sym;
3949
3950 sym = get_ksymbol(mod, addr, size, offset);
3951 if (!sym)
3952 goto out;
3953 if (modname)
3954 strlcpy(modname, mod->name, MODULE_NAME_LEN);
3955 if (name)
3956 strlcpy(name, sym, KSYM_NAME_LEN);
3957 preempt_enable();
3958 return 0;
3959 }
3960 }
3961out:
3962 preempt_enable();
3963 return -ERANGE;
3964}
3965
3966int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
3967 char *name, char *module_name, int *exported)
3968{
3969 struct module *mod;
3970
3971 preempt_disable();
3972 list_for_each_entry_rcu(mod, &modules, list) {
3973 struct mod_kallsyms *kallsyms;
3974
3975 if (mod->state == MODULE_STATE_UNFORMED)
3976 continue;
3977 kallsyms = rcu_dereference_sched(mod->kallsyms);
3978 if (symnum < kallsyms->num_symtab) {
3979 *value = kallsyms->symtab[symnum].st_value;
3980 *type = kallsyms->symtab[symnum].st_info;
3981 strlcpy(name, symname(kallsyms, symnum), KSYM_NAME_LEN);
3982 strlcpy(module_name, mod->name, MODULE_NAME_LEN);
3983 *exported = is_exported(name, *value, mod);
3984 preempt_enable();
3985 return 0;
3986 }
3987 symnum -= kallsyms->num_symtab;
3988 }
3989 preempt_enable();
3990 return -ERANGE;
3991}
3992
3993static unsigned long mod_find_symname(struct module *mod, const char *name)
3994{
3995 unsigned int i;
3996 struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
3997
3998 for (i = 0; i < kallsyms->num_symtab; i++)
3999 if (strcmp(name, symname(kallsyms, i)) == 0 &&
4000 kallsyms->symtab[i].st_info != 'U')
4001 return kallsyms->symtab[i].st_value;
4002 return 0;
4003}
4004
4005/* Look for this name: can be of form module:name. */
4006unsigned long module_kallsyms_lookup_name(const char *name)
4007{
4008 struct module *mod;
4009 char *colon;
4010 unsigned long ret = 0;
4011
4012 /* Don't lock: we're in enough trouble already. */
4013 preempt_disable();
4014 if ((colon = strchr(name, ':')) != NULL) {
4015 if ((mod = find_module_all(name, colon - name, false)) != NULL)
4016 ret = mod_find_symname(mod, colon+1);
4017 } else {
4018 list_for_each_entry_rcu(mod, &modules, list) {
4019 if (mod->state == MODULE_STATE_UNFORMED)
4020 continue;
4021 if ((ret = mod_find_symname(mod, name)) != 0)
4022 break;
4023 }
4024 }
4025 preempt_enable();
4026 return ret;
4027}
4028
4029int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
4030 struct module *, unsigned long),
4031 void *data)
4032{
4033 struct module *mod;
4034 unsigned int i;
4035 int ret;
4036
4037 module_assert_mutex();
4038
4039 list_for_each_entry(mod, &modules, list) {
4040 /* We hold module_mutex: no need for rcu_dereference_sched */
4041 struct mod_kallsyms *kallsyms = mod->kallsyms;
4042
4043 if (mod->state == MODULE_STATE_UNFORMED)
4044 continue;
4045 for (i = 0; i < kallsyms->num_symtab; i++) {
4046 ret = fn(data, symname(kallsyms, i),
4047 mod, kallsyms->symtab[i].st_value);
4048 if (ret != 0)
4049 return ret;
4050 }
4051 }
4052 return 0;
4053}
4054#endif /* CONFIG_KALLSYMS */
4055
4056/* Maximum number of characters written by module_flags() */
4057#define MODULE_FLAGS_BUF_SIZE (TAINT_FLAGS_COUNT + 4)
4058
4059/* Keep in sync with MODULE_FLAGS_BUF_SIZE !!! */
4060static char *module_flags(struct module *mod, char *buf)
4061{
4062 int bx = 0;
4063
4064 BUG_ON(mod->state == MODULE_STATE_UNFORMED);
4065 if (mod->taints ||
4066 mod->state == MODULE_STATE_GOING ||
4067 mod->state == MODULE_STATE_COMING) {
4068 buf[bx++] = '(';
4069 bx += module_flags_taint(mod, buf + bx);
4070 /* Show a - for module-is-being-unloaded */
4071 if (mod->state == MODULE_STATE_GOING)
4072 buf[bx++] = '-';
4073 /* Show a + for module-is-being-loaded */
4074 if (mod->state == MODULE_STATE_COMING)
4075 buf[bx++] = '+';
4076 buf[bx++] = ')';
4077 }
4078 buf[bx] = '\0';
4079
4080 return buf;
4081}
4082
4083#ifdef CONFIG_PROC_FS
4084/* Called by the /proc file system to return a list of modules. */
4085static void *m_start(struct seq_file *m, loff_t *pos)
4086{
4087 mutex_lock(&module_mutex);
4088 return seq_list_start(&modules, *pos);
4089}
4090
4091static void *m_next(struct seq_file *m, void *p, loff_t *pos)
4092{
4093 return seq_list_next(p, &modules, pos);
4094}
4095
4096static void m_stop(struct seq_file *m, void *p)
4097{
4098 mutex_unlock(&module_mutex);
4099}
4100
4101static int m_show(struct seq_file *m, void *p)
4102{
4103 struct module *mod = list_entry(p, struct module, list);
4104 char buf[MODULE_FLAGS_BUF_SIZE];
4105
4106 /* We always ignore unformed modules. */
4107 if (mod->state == MODULE_STATE_UNFORMED)
4108 return 0;
4109
4110 seq_printf(m, "%s %u",
4111 mod->name, mod->init_layout.size + mod->core_layout.size);
4112 print_unload_info(m, mod);
4113
4114 /* Informative for users. */
4115 seq_printf(m, " %s",
4116 mod->state == MODULE_STATE_GOING ? "Unloading" :
4117 mod->state == MODULE_STATE_COMING ? "Loading" :
4118 "Live");
4119 /* Used by oprofile and other similar tools. */
4120 seq_printf(m, " 0x%pK", mod->core_layout.base);
4121
4122 /* Taints info */
4123 if (mod->taints)
4124 seq_printf(m, " %s", module_flags(mod, buf));
4125
4126 seq_puts(m, "\n");
4127 return 0;
4128}
4129
4130/* Format: modulename size refcount deps address
4131
4132 Where refcount is a number or -, and deps is a comma-separated list
4133 of depends or -.
4134*/
4135static const struct seq_operations modules_op = {
4136 .start = m_start,
4137 .next = m_next,
4138 .stop = m_stop,
4139 .show = m_show
4140};
4141
4142static int modules_open(struct inode *inode, struct file *file)
4143{
4144 return seq_open(file, &modules_op);
4145}
4146
4147static const struct file_operations proc_modules_operations = {
4148 .open = modules_open,
4149 .read = seq_read,
4150 .llseek = seq_lseek,
4151 .release = seq_release,
4152};
4153
4154static int __init proc_modules_init(void)
4155{
4156 proc_create("modules", 0, NULL, &proc_modules_operations);
4157 return 0;
4158}
4159module_init(proc_modules_init);
4160#endif
4161
4162/* Given an address, look for it in the module exception tables. */
4163const struct exception_table_entry *search_module_extables(unsigned long addr)
4164{
4165 const struct exception_table_entry *e = NULL;
4166 struct module *mod;
4167
4168 preempt_disable();
4169 list_for_each_entry_rcu(mod, &modules, list) {
4170 if (mod->state == MODULE_STATE_UNFORMED)
4171 continue;
4172 if (mod->num_exentries == 0)
4173 continue;
4174
4175 e = search_extable(mod->extable,
4176 mod->extable + mod->num_exentries - 1,
4177 addr);
4178 if (e)
4179 break;
4180 }
4181 preempt_enable();
4182
4183 /* Now, if we found one, we are running inside it now, hence
4184 we cannot unload the module, hence no refcnt needed. */
4185 return e;
4186}
4187
4188/*
4189 * is_module_address - is this address inside a module?
4190 * @addr: the address to check.
4191 *
4192 * See is_module_text_address() if you simply want to see if the address
4193 * is code (not data).
4194 */
4195bool is_module_address(unsigned long addr)
4196{
4197 bool ret;
4198
4199 preempt_disable();
4200 ret = __module_address(addr) != NULL;
4201 preempt_enable();
4202
4203 return ret;
4204}
4205
4206/*
4207 * __module_address - get the module which contains an address.
4208 * @addr: the address.
4209 *
4210 * Must be called with preempt disabled or module mutex held so that
4211 * module doesn't get freed during this.
4212 */
4213struct module *__module_address(unsigned long addr)
4214{
4215 struct module *mod;
4216
4217 if (addr < module_addr_min || addr > module_addr_max)
4218 return NULL;
4219
4220 module_assert_mutex_or_preempt();
4221
4222 mod = mod_find(addr);
4223 if (mod) {
4224 BUG_ON(!within_module(addr, mod));
4225 if (mod->state == MODULE_STATE_UNFORMED)
4226 mod = NULL;
4227 }
4228 return mod;
4229}
4230EXPORT_SYMBOL_GPL(__module_address);
4231
4232/*
4233 * is_module_text_address - is this address inside module code?
4234 * @addr: the address to check.
4235 *
4236 * See is_module_address() if you simply want to see if the address is
4237 * anywhere in a module. See kernel_text_address() for testing if an
4238 * address corresponds to kernel or module code.
4239 */
4240bool is_module_text_address(unsigned long addr)
4241{
4242 bool ret;
4243
4244 preempt_disable();
4245 ret = __module_text_address(addr) != NULL;
4246 preempt_enable();
4247
4248 return ret;
4249}
4250
4251/*
4252 * __module_text_address - get the module whose code contains an address.
4253 * @addr: the address.
4254 *
4255 * Must be called with preempt disabled or module mutex held so that
4256 * module doesn't get freed during this.
4257 */
4258struct module *__module_text_address(unsigned long addr)
4259{
4260 struct module *mod = __module_address(addr);
4261 if (mod) {
4262 /* Make sure it's within the text section. */
4263 if (!within(addr, mod->init_layout.base, mod->init_layout.text_size)
4264 && !within(addr, mod->core_layout.base, mod->core_layout.text_size))
4265 mod = NULL;
4266 }
4267 return mod;
4268}
4269EXPORT_SYMBOL_GPL(__module_text_address);
4270
4271/* Don't grab lock, we're oopsing. */
4272void print_modules(void)
4273{
4274 struct module *mod;
4275 char buf[MODULE_FLAGS_BUF_SIZE];
4276
4277 printk(KERN_DEFAULT "Modules linked in:");
4278 /* Most callers should already have preempt disabled, but make sure */
4279 preempt_disable();
4280 list_for_each_entry_rcu(mod, &modules, list) {
4281 if (mod->state == MODULE_STATE_UNFORMED)
4282 continue;
4283 pr_cont(" %s%s", mod->name, module_flags(mod, buf));
4284 }
4285 preempt_enable();
4286 if (last_unloaded_module[0])
4287 pr_cont(" [last unloaded: %s]", last_unloaded_module);
4288 pr_cont("\n");
4289}
4290
4291#ifdef CONFIG_MODVERSIONS
4292/* Generate the signature for all relevant module structures here.
4293 * If these change, we don't want to try to parse the module. */
4294void module_layout(struct module *mod,
4295 struct modversion_info *ver,
4296 struct kernel_param *kp,
4297 struct kernel_symbol *ks,
4298 struct tracepoint * const *tp)
4299{
4300}
4301EXPORT_SYMBOL(module_layout);
4302#endif
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/ftrace_event.h>
22#include <linux/init.h>
23#include <linux/kallsyms.h>
24#include <linux/fs.h>
25#include <linux/sysfs.h>
26#include <linux/kernel.h>
27#include <linux/slab.h>
28#include <linux/vmalloc.h>
29#include <linux/elf.h>
30#include <linux/proc_fs.h>
31#include <linux/seq_file.h>
32#include <linux/syscalls.h>
33#include <linux/fcntl.h>
34#include <linux/rcupdate.h>
35#include <linux/capability.h>
36#include <linux/cpu.h>
37#include <linux/moduleparam.h>
38#include <linux/errno.h>
39#include <linux/err.h>
40#include <linux/vermagic.h>
41#include <linux/notifier.h>
42#include <linux/sched.h>
43#include <linux/stop_machine.h>
44#include <linux/device.h>
45#include <linux/string.h>
46#include <linux/mutex.h>
47#include <linux/rculist.h>
48#include <asm/uaccess.h>
49#include <asm/cacheflush.h>
50#include <asm/mmu_context.h>
51#include <linux/license.h>
52#include <asm/sections.h>
53#include <linux/tracepoint.h>
54#include <linux/ftrace.h>
55#include <linux/async.h>
56#include <linux/percpu.h>
57#include <linux/kmemleak.h>
58#include <linux/jump_label.h>
59#include <linux/pfn.h>
60#include <linux/bsearch.h>
61
62#define CREATE_TRACE_POINTS
63#include <trace/events/module.h>
64
65#ifndef ARCH_SHF_SMALL
66#define ARCH_SHF_SMALL 0
67#endif
68
69/*
70 * Modules' sections will be aligned on page boundaries
71 * to ensure complete separation of code and data, but
72 * only when CONFIG_DEBUG_SET_MODULE_RONX=y
73 */
74#ifdef CONFIG_DEBUG_SET_MODULE_RONX
75# define debug_align(X) ALIGN(X, PAGE_SIZE)
76#else
77# define debug_align(X) (X)
78#endif
79
80/*
81 * Given BASE and SIZE this macro calculates the number of pages the
82 * memory regions occupies
83 */
84#define MOD_NUMBER_OF_PAGES(BASE, SIZE) (((SIZE) > 0) ? \
85 (PFN_DOWN((unsigned long)(BASE) + (SIZE) - 1) - \
86 PFN_DOWN((unsigned long)BASE) + 1) \
87 : (0UL))
88
89/* If this is set, the section belongs in the init part of the module */
90#define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
91
92/*
93 * Mutex protects:
94 * 1) List of modules (also safely readable with preempt_disable),
95 * 2) module_use links,
96 * 3) module_addr_min/module_addr_max.
97 * (delete uses stop_machine/add uses RCU list operations). */
98DEFINE_MUTEX(module_mutex);
99EXPORT_SYMBOL_GPL(module_mutex);
100static LIST_HEAD(modules);
101#ifdef CONFIG_KGDB_KDB
102struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
103#endif /* CONFIG_KGDB_KDB */
104
105
106/* Block module loading/unloading? */
107int modules_disabled = 0;
108core_param(nomodule, modules_disabled, bint, 0);
109
110/* Waiting for a module to finish initializing? */
111static DECLARE_WAIT_QUEUE_HEAD(module_wq);
112
113static BLOCKING_NOTIFIER_HEAD(module_notify_list);
114
115/* Bounds of module allocation, for speeding __module_address.
116 * Protected by module_mutex. */
117static unsigned long module_addr_min = -1UL, module_addr_max = 0;
118
119int register_module_notifier(struct notifier_block * nb)
120{
121 return blocking_notifier_chain_register(&module_notify_list, nb);
122}
123EXPORT_SYMBOL(register_module_notifier);
124
125int unregister_module_notifier(struct notifier_block * nb)
126{
127 return blocking_notifier_chain_unregister(&module_notify_list, nb);
128}
129EXPORT_SYMBOL(unregister_module_notifier);
130
131struct load_info {
132 Elf_Ehdr *hdr;
133 unsigned long len;
134 Elf_Shdr *sechdrs;
135 char *secstrings, *strtab;
136 unsigned long symoffs, stroffs;
137 struct _ddebug *debug;
138 unsigned int num_debug;
139 struct {
140 unsigned int sym, str, mod, vers, info, pcpu;
141 } index;
142};
143
144/* We require a truly strong try_module_get(): 0 means failure due to
145 ongoing or failed initialization etc. */
146static inline int strong_try_module_get(struct module *mod)
147{
148 if (mod && mod->state == MODULE_STATE_COMING)
149 return -EBUSY;
150 if (try_module_get(mod))
151 return 0;
152 else
153 return -ENOENT;
154}
155
156static inline void add_taint_module(struct module *mod, unsigned flag)
157{
158 add_taint(flag);
159 mod->taints |= (1U << flag);
160}
161
162/*
163 * A thread that wants to hold a reference to a module only while it
164 * is running can call this to safely exit. nfsd and lockd use this.
165 */
166void __module_put_and_exit(struct module *mod, long code)
167{
168 module_put(mod);
169 do_exit(code);
170}
171EXPORT_SYMBOL(__module_put_and_exit);
172
173/* Find a module section: 0 means not found. */
174static unsigned int find_sec(const struct load_info *info, const char *name)
175{
176 unsigned int i;
177
178 for (i = 1; i < info->hdr->e_shnum; i++) {
179 Elf_Shdr *shdr = &info->sechdrs[i];
180 /* Alloc bit cleared means "ignore it." */
181 if ((shdr->sh_flags & SHF_ALLOC)
182 && strcmp(info->secstrings + shdr->sh_name, name) == 0)
183 return i;
184 }
185 return 0;
186}
187
188/* Find a module section, or NULL. */
189static void *section_addr(const struct load_info *info, const char *name)
190{
191 /* Section 0 has sh_addr 0. */
192 return (void *)info->sechdrs[find_sec(info, name)].sh_addr;
193}
194
195/* Find a module section, or NULL. Fill in number of "objects" in section. */
196static void *section_objs(const struct load_info *info,
197 const char *name,
198 size_t object_size,
199 unsigned int *num)
200{
201 unsigned int sec = find_sec(info, name);
202
203 /* Section 0 has sh_addr 0 and sh_size 0. */
204 *num = info->sechdrs[sec].sh_size / object_size;
205 return (void *)info->sechdrs[sec].sh_addr;
206}
207
208/* Provided by the linker */
209extern const struct kernel_symbol __start___ksymtab[];
210extern const struct kernel_symbol __stop___ksymtab[];
211extern const struct kernel_symbol __start___ksymtab_gpl[];
212extern const struct kernel_symbol __stop___ksymtab_gpl[];
213extern const struct kernel_symbol __start___ksymtab_gpl_future[];
214extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
215extern const unsigned long __start___kcrctab[];
216extern const unsigned long __start___kcrctab_gpl[];
217extern const unsigned long __start___kcrctab_gpl_future[];
218#ifdef CONFIG_UNUSED_SYMBOLS
219extern const struct kernel_symbol __start___ksymtab_unused[];
220extern const struct kernel_symbol __stop___ksymtab_unused[];
221extern const struct kernel_symbol __start___ksymtab_unused_gpl[];
222extern const struct kernel_symbol __stop___ksymtab_unused_gpl[];
223extern const unsigned long __start___kcrctab_unused[];
224extern const unsigned long __start___kcrctab_unused_gpl[];
225#endif
226
227#ifndef CONFIG_MODVERSIONS
228#define symversion(base, idx) NULL
229#else
230#define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
231#endif
232
233static bool each_symbol_in_section(const struct symsearch *arr,
234 unsigned int arrsize,
235 struct module *owner,
236 bool (*fn)(const struct symsearch *syms,
237 struct module *owner,
238 void *data),
239 void *data)
240{
241 unsigned int j;
242
243 for (j = 0; j < arrsize; j++) {
244 if (fn(&arr[j], owner, data))
245 return true;
246 }
247
248 return false;
249}
250
251/* Returns true as soon as fn returns true, otherwise false. */
252bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
253 struct module *owner,
254 void *data),
255 void *data)
256{
257 struct module *mod;
258 static const struct symsearch arr[] = {
259 { __start___ksymtab, __stop___ksymtab, __start___kcrctab,
260 NOT_GPL_ONLY, false },
261 { __start___ksymtab_gpl, __stop___ksymtab_gpl,
262 __start___kcrctab_gpl,
263 GPL_ONLY, false },
264 { __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future,
265 __start___kcrctab_gpl_future,
266 WILL_BE_GPL_ONLY, false },
267#ifdef CONFIG_UNUSED_SYMBOLS
268 { __start___ksymtab_unused, __stop___ksymtab_unused,
269 __start___kcrctab_unused,
270 NOT_GPL_ONLY, true },
271 { __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl,
272 __start___kcrctab_unused_gpl,
273 GPL_ONLY, true },
274#endif
275 };
276
277 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data))
278 return true;
279
280 list_for_each_entry_rcu(mod, &modules, list) {
281 struct symsearch arr[] = {
282 { mod->syms, mod->syms + mod->num_syms, mod->crcs,
283 NOT_GPL_ONLY, false },
284 { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
285 mod->gpl_crcs,
286 GPL_ONLY, false },
287 { mod->gpl_future_syms,
288 mod->gpl_future_syms + mod->num_gpl_future_syms,
289 mod->gpl_future_crcs,
290 WILL_BE_GPL_ONLY, false },
291#ifdef CONFIG_UNUSED_SYMBOLS
292 { mod->unused_syms,
293 mod->unused_syms + mod->num_unused_syms,
294 mod->unused_crcs,
295 NOT_GPL_ONLY, true },
296 { mod->unused_gpl_syms,
297 mod->unused_gpl_syms + mod->num_unused_gpl_syms,
298 mod->unused_gpl_crcs,
299 GPL_ONLY, true },
300#endif
301 };
302
303 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data))
304 return true;
305 }
306 return false;
307}
308EXPORT_SYMBOL_GPL(each_symbol_section);
309
310struct find_symbol_arg {
311 /* Input */
312 const char *name;
313 bool gplok;
314 bool warn;
315
316 /* Output */
317 struct module *owner;
318 const unsigned long *crc;
319 const struct kernel_symbol *sym;
320};
321
322static bool check_symbol(const struct symsearch *syms,
323 struct module *owner,
324 unsigned int symnum, void *data)
325{
326 struct find_symbol_arg *fsa = data;
327
328 if (!fsa->gplok) {
329 if (syms->licence == GPL_ONLY)
330 return false;
331 if (syms->licence == WILL_BE_GPL_ONLY && fsa->warn) {
332 printk(KERN_WARNING "Symbol %s is being used "
333 "by a non-GPL module, which will not "
334 "be allowed in the future\n", fsa->name);
335 printk(KERN_WARNING "Please see the file "
336 "Documentation/feature-removal-schedule.txt "
337 "in the kernel source tree for more details.\n");
338 }
339 }
340
341#ifdef CONFIG_UNUSED_SYMBOLS
342 if (syms->unused && fsa->warn) {
343 printk(KERN_WARNING "Symbol %s is marked as UNUSED, "
344 "however this module is using it.\n", fsa->name);
345 printk(KERN_WARNING
346 "This symbol will go away in the future.\n");
347 printk(KERN_WARNING
348 "Please evalute if this is the right api to use and if "
349 "it really is, submit a report the linux kernel "
350 "mailinglist together with submitting your code for "
351 "inclusion.\n");
352 }
353#endif
354
355 fsa->owner = owner;
356 fsa->crc = symversion(syms->crcs, symnum);
357 fsa->sym = &syms->start[symnum];
358 return true;
359}
360
361static int cmp_name(const void *va, const void *vb)
362{
363 const char *a;
364 const struct kernel_symbol *b;
365 a = va; b = vb;
366 return strcmp(a, b->name);
367}
368
369static bool find_symbol_in_section(const struct symsearch *syms,
370 struct module *owner,
371 void *data)
372{
373 struct find_symbol_arg *fsa = data;
374 struct kernel_symbol *sym;
375
376 sym = bsearch(fsa->name, syms->start, syms->stop - syms->start,
377 sizeof(struct kernel_symbol), cmp_name);
378
379 if (sym != NULL && check_symbol(syms, owner, sym - syms->start, data))
380 return true;
381
382 return false;
383}
384
385/* Find a symbol and return it, along with, (optional) crc and
386 * (optional) module which owns it. Needs preempt disabled or module_mutex. */
387const struct kernel_symbol *find_symbol(const char *name,
388 struct module **owner,
389 const unsigned long **crc,
390 bool gplok,
391 bool warn)
392{
393 struct find_symbol_arg fsa;
394
395 fsa.name = name;
396 fsa.gplok = gplok;
397 fsa.warn = warn;
398
399 if (each_symbol_section(find_symbol_in_section, &fsa)) {
400 if (owner)
401 *owner = fsa.owner;
402 if (crc)
403 *crc = fsa.crc;
404 return fsa.sym;
405 }
406
407 pr_debug("Failed to find symbol %s\n", name);
408 return NULL;
409}
410EXPORT_SYMBOL_GPL(find_symbol);
411
412/* Search for module by name: must hold module_mutex. */
413struct module *find_module(const char *name)
414{
415 struct module *mod;
416
417 list_for_each_entry(mod, &modules, list) {
418 if (strcmp(mod->name, name) == 0)
419 return mod;
420 }
421 return NULL;
422}
423EXPORT_SYMBOL_GPL(find_module);
424
425#ifdef CONFIG_SMP
426
427static inline void __percpu *mod_percpu(struct module *mod)
428{
429 return mod->percpu;
430}
431
432static int percpu_modalloc(struct module *mod,
433 unsigned long size, unsigned long align)
434{
435 if (align > PAGE_SIZE) {
436 printk(KERN_WARNING "%s: per-cpu alignment %li > %li\n",
437 mod->name, align, PAGE_SIZE);
438 align = PAGE_SIZE;
439 }
440
441 mod->percpu = __alloc_reserved_percpu(size, align);
442 if (!mod->percpu) {
443 printk(KERN_WARNING
444 "%s: Could not allocate %lu bytes percpu data\n",
445 mod->name, size);
446 return -ENOMEM;
447 }
448 mod->percpu_size = size;
449 return 0;
450}
451
452static void percpu_modfree(struct module *mod)
453{
454 free_percpu(mod->percpu);
455}
456
457static unsigned int find_pcpusec(struct load_info *info)
458{
459 return find_sec(info, ".data..percpu");
460}
461
462static void percpu_modcopy(struct module *mod,
463 const void *from, unsigned long size)
464{
465 int cpu;
466
467 for_each_possible_cpu(cpu)
468 memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
469}
470
471/**
472 * is_module_percpu_address - test whether address is from module static percpu
473 * @addr: address to test
474 *
475 * Test whether @addr belongs to module static percpu area.
476 *
477 * RETURNS:
478 * %true if @addr is from module static percpu area
479 */
480bool is_module_percpu_address(unsigned long addr)
481{
482 struct module *mod;
483 unsigned int cpu;
484
485 preempt_disable();
486
487 list_for_each_entry_rcu(mod, &modules, list) {
488 if (!mod->percpu_size)
489 continue;
490 for_each_possible_cpu(cpu) {
491 void *start = per_cpu_ptr(mod->percpu, cpu);
492
493 if ((void *)addr >= start &&
494 (void *)addr < start + mod->percpu_size) {
495 preempt_enable();
496 return true;
497 }
498 }
499 }
500
501 preempt_enable();
502 return false;
503}
504
505#else /* ... !CONFIG_SMP */
506
507static inline void __percpu *mod_percpu(struct module *mod)
508{
509 return NULL;
510}
511static inline int percpu_modalloc(struct module *mod,
512 unsigned long size, unsigned long align)
513{
514 return -ENOMEM;
515}
516static inline void percpu_modfree(struct module *mod)
517{
518}
519static unsigned int find_pcpusec(struct load_info *info)
520{
521 return 0;
522}
523static inline void percpu_modcopy(struct module *mod,
524 const void *from, unsigned long size)
525{
526 /* pcpusec should be 0, and size of that section should be 0. */
527 BUG_ON(size != 0);
528}
529bool is_module_percpu_address(unsigned long addr)
530{
531 return false;
532}
533
534#endif /* CONFIG_SMP */
535
536#define MODINFO_ATTR(field) \
537static void setup_modinfo_##field(struct module *mod, const char *s) \
538{ \
539 mod->field = kstrdup(s, GFP_KERNEL); \
540} \
541static ssize_t show_modinfo_##field(struct module_attribute *mattr, \
542 struct module_kobject *mk, char *buffer) \
543{ \
544 return sprintf(buffer, "%s\n", mk->mod->field); \
545} \
546static int modinfo_##field##_exists(struct module *mod) \
547{ \
548 return mod->field != NULL; \
549} \
550static void free_modinfo_##field(struct module *mod) \
551{ \
552 kfree(mod->field); \
553 mod->field = NULL; \
554} \
555static struct module_attribute modinfo_##field = { \
556 .attr = { .name = __stringify(field), .mode = 0444 }, \
557 .show = show_modinfo_##field, \
558 .setup = setup_modinfo_##field, \
559 .test = modinfo_##field##_exists, \
560 .free = free_modinfo_##field, \
561};
562
563MODINFO_ATTR(version);
564MODINFO_ATTR(srcversion);
565
566static char last_unloaded_module[MODULE_NAME_LEN+1];
567
568#ifdef CONFIG_MODULE_UNLOAD
569
570EXPORT_TRACEPOINT_SYMBOL(module_get);
571
572/* Init the unload section of the module. */
573static int module_unload_init(struct module *mod)
574{
575 mod->refptr = alloc_percpu(struct module_ref);
576 if (!mod->refptr)
577 return -ENOMEM;
578
579 INIT_LIST_HEAD(&mod->source_list);
580 INIT_LIST_HEAD(&mod->target_list);
581
582 /* Hold reference count during initialization. */
583 __this_cpu_write(mod->refptr->incs, 1);
584 /* Backwards compatibility macros put refcount during init. */
585 mod->waiter = current;
586
587 return 0;
588}
589
590/* Does a already use b? */
591static int already_uses(struct module *a, struct module *b)
592{
593 struct module_use *use;
594
595 list_for_each_entry(use, &b->source_list, source_list) {
596 if (use->source == a) {
597 pr_debug("%s uses %s!\n", a->name, b->name);
598 return 1;
599 }
600 }
601 pr_debug("%s does not use %s!\n", a->name, b->name);
602 return 0;
603}
604
605/*
606 * Module a uses b
607 * - we add 'a' as a "source", 'b' as a "target" of module use
608 * - the module_use is added to the list of 'b' sources (so
609 * 'b' can walk the list to see who sourced them), and of 'a'
610 * targets (so 'a' can see what modules it targets).
611 */
612static int add_module_usage(struct module *a, struct module *b)
613{
614 struct module_use *use;
615
616 pr_debug("Allocating new usage for %s.\n", a->name);
617 use = kmalloc(sizeof(*use), GFP_ATOMIC);
618 if (!use) {
619 printk(KERN_WARNING "%s: out of memory loading\n", a->name);
620 return -ENOMEM;
621 }
622
623 use->source = a;
624 use->target = b;
625 list_add(&use->source_list, &b->source_list);
626 list_add(&use->target_list, &a->target_list);
627 return 0;
628}
629
630/* Module a uses b: caller needs module_mutex() */
631int ref_module(struct module *a, struct module *b)
632{
633 int err;
634
635 if (b == NULL || already_uses(a, b))
636 return 0;
637
638 /* If module isn't available, we fail. */
639 err = strong_try_module_get(b);
640 if (err)
641 return err;
642
643 err = add_module_usage(a, b);
644 if (err) {
645 module_put(b);
646 return err;
647 }
648 return 0;
649}
650EXPORT_SYMBOL_GPL(ref_module);
651
652/* Clear the unload stuff of the module. */
653static void module_unload_free(struct module *mod)
654{
655 struct module_use *use, *tmp;
656
657 mutex_lock(&module_mutex);
658 list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
659 struct module *i = use->target;
660 pr_debug("%s unusing %s\n", mod->name, i->name);
661 module_put(i);
662 list_del(&use->source_list);
663 list_del(&use->target_list);
664 kfree(use);
665 }
666 mutex_unlock(&module_mutex);
667
668 free_percpu(mod->refptr);
669}
670
671#ifdef CONFIG_MODULE_FORCE_UNLOAD
672static inline int try_force_unload(unsigned int flags)
673{
674 int ret = (flags & O_TRUNC);
675 if (ret)
676 add_taint(TAINT_FORCED_RMMOD);
677 return ret;
678}
679#else
680static inline int try_force_unload(unsigned int flags)
681{
682 return 0;
683}
684#endif /* CONFIG_MODULE_FORCE_UNLOAD */
685
686struct stopref
687{
688 struct module *mod;
689 int flags;
690 int *forced;
691};
692
693/* Whole machine is stopped with interrupts off when this runs. */
694static int __try_stop_module(void *_sref)
695{
696 struct stopref *sref = _sref;
697
698 /* If it's not unused, quit unless we're forcing. */
699 if (module_refcount(sref->mod) != 0) {
700 if (!(*sref->forced = try_force_unload(sref->flags)))
701 return -EWOULDBLOCK;
702 }
703
704 /* Mark it as dying. */
705 sref->mod->state = MODULE_STATE_GOING;
706 return 0;
707}
708
709static int try_stop_module(struct module *mod, int flags, int *forced)
710{
711 if (flags & O_NONBLOCK) {
712 struct stopref sref = { mod, flags, forced };
713
714 return stop_machine(__try_stop_module, &sref, NULL);
715 } else {
716 /* We don't need to stop the machine for this. */
717 mod->state = MODULE_STATE_GOING;
718 synchronize_sched();
719 return 0;
720 }
721}
722
723unsigned long module_refcount(struct module *mod)
724{
725 unsigned long incs = 0, decs = 0;
726 int cpu;
727
728 for_each_possible_cpu(cpu)
729 decs += per_cpu_ptr(mod->refptr, cpu)->decs;
730 /*
731 * ensure the incs are added up after the decs.
732 * module_put ensures incs are visible before decs with smp_wmb.
733 *
734 * This 2-count scheme avoids the situation where the refcount
735 * for CPU0 is read, then CPU0 increments the module refcount,
736 * then CPU1 drops that refcount, then the refcount for CPU1 is
737 * read. We would record a decrement but not its corresponding
738 * increment so we would see a low count (disaster).
739 *
740 * Rare situation? But module_refcount can be preempted, and we
741 * might be tallying up 4096+ CPUs. So it is not impossible.
742 */
743 smp_rmb();
744 for_each_possible_cpu(cpu)
745 incs += per_cpu_ptr(mod->refptr, cpu)->incs;
746 return incs - decs;
747}
748EXPORT_SYMBOL(module_refcount);
749
750/* This exists whether we can unload or not */
751static void free_module(struct module *mod);
752
753static void wait_for_zero_refcount(struct module *mod)
754{
755 /* Since we might sleep for some time, release the mutex first */
756 mutex_unlock(&module_mutex);
757 for (;;) {
758 pr_debug("Looking at refcount...\n");
759 set_current_state(TASK_UNINTERRUPTIBLE);
760 if (module_refcount(mod) == 0)
761 break;
762 schedule();
763 }
764 current->state = TASK_RUNNING;
765 mutex_lock(&module_mutex);
766}
767
768SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
769 unsigned int, flags)
770{
771 struct module *mod;
772 char name[MODULE_NAME_LEN];
773 int ret, forced = 0;
774
775 if (!capable(CAP_SYS_MODULE) || modules_disabled)
776 return -EPERM;
777
778 if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
779 return -EFAULT;
780 name[MODULE_NAME_LEN-1] = '\0';
781
782 if (mutex_lock_interruptible(&module_mutex) != 0)
783 return -EINTR;
784
785 mod = find_module(name);
786 if (!mod) {
787 ret = -ENOENT;
788 goto out;
789 }
790
791 if (!list_empty(&mod->source_list)) {
792 /* Other modules depend on us: get rid of them first. */
793 ret = -EWOULDBLOCK;
794 goto out;
795 }
796
797 /* Doing init or already dying? */
798 if (mod->state != MODULE_STATE_LIVE) {
799 /* FIXME: if (force), slam module count and wake up
800 waiter --RR */
801 pr_debug("%s already dying\n", mod->name);
802 ret = -EBUSY;
803 goto out;
804 }
805
806 /* If it has an init func, it must have an exit func to unload */
807 if (mod->init && !mod->exit) {
808 forced = try_force_unload(flags);
809 if (!forced) {
810 /* This module can't be removed */
811 ret = -EBUSY;
812 goto out;
813 }
814 }
815
816 /* Set this up before setting mod->state */
817 mod->waiter = current;
818
819 /* Stop the machine so refcounts can't move and disable module. */
820 ret = try_stop_module(mod, flags, &forced);
821 if (ret != 0)
822 goto out;
823
824 /* Never wait if forced. */
825 if (!forced && module_refcount(mod) != 0)
826 wait_for_zero_refcount(mod);
827
828 mutex_unlock(&module_mutex);
829 /* Final destruction now no one is using it. */
830 if (mod->exit != NULL)
831 mod->exit();
832 blocking_notifier_call_chain(&module_notify_list,
833 MODULE_STATE_GOING, mod);
834 async_synchronize_full();
835
836 /* Store the name of the last unloaded module for diagnostic purposes */
837 strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
838
839 free_module(mod);
840 return 0;
841out:
842 mutex_unlock(&module_mutex);
843 return ret;
844}
845
846static inline void print_unload_info(struct seq_file *m, struct module *mod)
847{
848 struct module_use *use;
849 int printed_something = 0;
850
851 seq_printf(m, " %lu ", module_refcount(mod));
852
853 /* Always include a trailing , so userspace can differentiate
854 between this and the old multi-field proc format. */
855 list_for_each_entry(use, &mod->source_list, source_list) {
856 printed_something = 1;
857 seq_printf(m, "%s,", use->source->name);
858 }
859
860 if (mod->init != NULL && mod->exit == NULL) {
861 printed_something = 1;
862 seq_printf(m, "[permanent],");
863 }
864
865 if (!printed_something)
866 seq_printf(m, "-");
867}
868
869void __symbol_put(const char *symbol)
870{
871 struct module *owner;
872
873 preempt_disable();
874 if (!find_symbol(symbol, &owner, NULL, true, false))
875 BUG();
876 module_put(owner);
877 preempt_enable();
878}
879EXPORT_SYMBOL(__symbol_put);
880
881/* Note this assumes addr is a function, which it currently always is. */
882void symbol_put_addr(void *addr)
883{
884 struct module *modaddr;
885 unsigned long a = (unsigned long)dereference_function_descriptor(addr);
886
887 if (core_kernel_text(a))
888 return;
889
890 /* module_text_address is safe here: we're supposed to have reference
891 * to module from symbol_get, so it can't go away. */
892 modaddr = __module_text_address(a);
893 BUG_ON(!modaddr);
894 module_put(modaddr);
895}
896EXPORT_SYMBOL_GPL(symbol_put_addr);
897
898static ssize_t show_refcnt(struct module_attribute *mattr,
899 struct module_kobject *mk, char *buffer)
900{
901 return sprintf(buffer, "%lu\n", module_refcount(mk->mod));
902}
903
904static struct module_attribute modinfo_refcnt =
905 __ATTR(refcnt, 0444, show_refcnt, NULL);
906
907void __module_get(struct module *module)
908{
909 if (module) {
910 preempt_disable();
911 __this_cpu_inc(module->refptr->incs);
912 trace_module_get(module, _RET_IP_);
913 preempt_enable();
914 }
915}
916EXPORT_SYMBOL(__module_get);
917
918bool try_module_get(struct module *module)
919{
920 bool ret = true;
921
922 if (module) {
923 preempt_disable();
924
925 if (likely(module_is_live(module))) {
926 __this_cpu_inc(module->refptr->incs);
927 trace_module_get(module, _RET_IP_);
928 } else
929 ret = false;
930
931 preempt_enable();
932 }
933 return ret;
934}
935EXPORT_SYMBOL(try_module_get);
936
937void module_put(struct module *module)
938{
939 if (module) {
940 preempt_disable();
941 smp_wmb(); /* see comment in module_refcount */
942 __this_cpu_inc(module->refptr->decs);
943
944 trace_module_put(module, _RET_IP_);
945 /* Maybe they're waiting for us to drop reference? */
946 if (unlikely(!module_is_live(module)))
947 wake_up_process(module->waiter);
948 preempt_enable();
949 }
950}
951EXPORT_SYMBOL(module_put);
952
953#else /* !CONFIG_MODULE_UNLOAD */
954static inline void print_unload_info(struct seq_file *m, struct module *mod)
955{
956 /* We don't know the usage count, or what modules are using. */
957 seq_printf(m, " - -");
958}
959
960static inline void module_unload_free(struct module *mod)
961{
962}
963
964int ref_module(struct module *a, struct module *b)
965{
966 return strong_try_module_get(b);
967}
968EXPORT_SYMBOL_GPL(ref_module);
969
970static inline int module_unload_init(struct module *mod)
971{
972 return 0;
973}
974#endif /* CONFIG_MODULE_UNLOAD */
975
976static size_t module_flags_taint(struct module *mod, char *buf)
977{
978 size_t l = 0;
979
980 if (mod->taints & (1 << TAINT_PROPRIETARY_MODULE))
981 buf[l++] = 'P';
982 if (mod->taints & (1 << TAINT_OOT_MODULE))
983 buf[l++] = 'O';
984 if (mod->taints & (1 << TAINT_FORCED_MODULE))
985 buf[l++] = 'F';
986 if (mod->taints & (1 << TAINT_CRAP))
987 buf[l++] = 'C';
988 /*
989 * TAINT_FORCED_RMMOD: could be added.
990 * TAINT_UNSAFE_SMP, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't
991 * apply to modules.
992 */
993 return l;
994}
995
996static ssize_t show_initstate(struct module_attribute *mattr,
997 struct module_kobject *mk, char *buffer)
998{
999 const char *state = "unknown";
1000
1001 switch (mk->mod->state) {
1002 case MODULE_STATE_LIVE:
1003 state = "live";
1004 break;
1005 case MODULE_STATE_COMING:
1006 state = "coming";
1007 break;
1008 case MODULE_STATE_GOING:
1009 state = "going";
1010 break;
1011 }
1012 return sprintf(buffer, "%s\n", state);
1013}
1014
1015static struct module_attribute modinfo_initstate =
1016 __ATTR(initstate, 0444, show_initstate, NULL);
1017
1018static ssize_t store_uevent(struct module_attribute *mattr,
1019 struct module_kobject *mk,
1020 const char *buffer, size_t count)
1021{
1022 enum kobject_action action;
1023
1024 if (kobject_action_type(buffer, count, &action) == 0)
1025 kobject_uevent(&mk->kobj, action);
1026 return count;
1027}
1028
1029struct module_attribute module_uevent =
1030 __ATTR(uevent, 0200, NULL, store_uevent);
1031
1032static ssize_t show_coresize(struct module_attribute *mattr,
1033 struct module_kobject *mk, char *buffer)
1034{
1035 return sprintf(buffer, "%u\n", mk->mod->core_size);
1036}
1037
1038static struct module_attribute modinfo_coresize =
1039 __ATTR(coresize, 0444, show_coresize, NULL);
1040
1041static ssize_t show_initsize(struct module_attribute *mattr,
1042 struct module_kobject *mk, char *buffer)
1043{
1044 return sprintf(buffer, "%u\n", mk->mod->init_size);
1045}
1046
1047static struct module_attribute modinfo_initsize =
1048 __ATTR(initsize, 0444, show_initsize, NULL);
1049
1050static ssize_t show_taint(struct module_attribute *mattr,
1051 struct module_kobject *mk, char *buffer)
1052{
1053 size_t l;
1054
1055 l = module_flags_taint(mk->mod, buffer);
1056 buffer[l++] = '\n';
1057 return l;
1058}
1059
1060static struct module_attribute modinfo_taint =
1061 __ATTR(taint, 0444, show_taint, NULL);
1062
1063static struct module_attribute *modinfo_attrs[] = {
1064 &module_uevent,
1065 &modinfo_version,
1066 &modinfo_srcversion,
1067 &modinfo_initstate,
1068 &modinfo_coresize,
1069 &modinfo_initsize,
1070 &modinfo_taint,
1071#ifdef CONFIG_MODULE_UNLOAD
1072 &modinfo_refcnt,
1073#endif
1074 NULL,
1075};
1076
1077static const char vermagic[] = VERMAGIC_STRING;
1078
1079static int try_to_force_load(struct module *mod, const char *reason)
1080{
1081#ifdef CONFIG_MODULE_FORCE_LOAD
1082 if (!test_taint(TAINT_FORCED_MODULE))
1083 printk(KERN_WARNING "%s: %s: kernel tainted.\n",
1084 mod->name, reason);
1085 add_taint_module(mod, TAINT_FORCED_MODULE);
1086 return 0;
1087#else
1088 return -ENOEXEC;
1089#endif
1090}
1091
1092#ifdef CONFIG_MODVERSIONS
1093/* If the arch applies (non-zero) relocations to kernel kcrctab, unapply it. */
1094static unsigned long maybe_relocated(unsigned long crc,
1095 const struct module *crc_owner)
1096{
1097#ifdef ARCH_RELOCATES_KCRCTAB
1098 if (crc_owner == NULL)
1099 return crc - (unsigned long)reloc_start;
1100#endif
1101 return crc;
1102}
1103
1104static int check_version(Elf_Shdr *sechdrs,
1105 unsigned int versindex,
1106 const char *symname,
1107 struct module *mod,
1108 const unsigned long *crc,
1109 const struct module *crc_owner)
1110{
1111 unsigned int i, num_versions;
1112 struct modversion_info *versions;
1113
1114 /* Exporting module didn't supply crcs? OK, we're already tainted. */
1115 if (!crc)
1116 return 1;
1117
1118 /* No versions at all? modprobe --force does this. */
1119 if (versindex == 0)
1120 return try_to_force_load(mod, symname) == 0;
1121
1122 versions = (void *) sechdrs[versindex].sh_addr;
1123 num_versions = sechdrs[versindex].sh_size
1124 / sizeof(struct modversion_info);
1125
1126 for (i = 0; i < num_versions; i++) {
1127 if (strcmp(versions[i].name, symname) != 0)
1128 continue;
1129
1130 if (versions[i].crc == maybe_relocated(*crc, crc_owner))
1131 return 1;
1132 pr_debug("Found checksum %lX vs module %lX\n",
1133 maybe_relocated(*crc, crc_owner), versions[i].crc);
1134 goto bad_version;
1135 }
1136
1137 printk(KERN_WARNING "%s: no symbol version for %s\n",
1138 mod->name, symname);
1139 return 0;
1140
1141bad_version:
1142 printk("%s: disagrees about version of symbol %s\n",
1143 mod->name, symname);
1144 return 0;
1145}
1146
1147static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1148 unsigned int versindex,
1149 struct module *mod)
1150{
1151 const unsigned long *crc;
1152
1153 /* Since this should be found in kernel (which can't be removed),
1154 * no locking is necessary. */
1155 if (!find_symbol(MODULE_SYMBOL_PREFIX "module_layout", NULL,
1156 &crc, true, false))
1157 BUG();
1158 return check_version(sechdrs, versindex, "module_layout", mod, crc,
1159 NULL);
1160}
1161
1162/* First part is kernel version, which we ignore if module has crcs. */
1163static inline int same_magic(const char *amagic, const char *bmagic,
1164 bool has_crcs)
1165{
1166 if (has_crcs) {
1167 amagic += strcspn(amagic, " ");
1168 bmagic += strcspn(bmagic, " ");
1169 }
1170 return strcmp(amagic, bmagic) == 0;
1171}
1172#else
1173static inline int check_version(Elf_Shdr *sechdrs,
1174 unsigned int versindex,
1175 const char *symname,
1176 struct module *mod,
1177 const unsigned long *crc,
1178 const struct module *crc_owner)
1179{
1180 return 1;
1181}
1182
1183static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1184 unsigned int versindex,
1185 struct module *mod)
1186{
1187 return 1;
1188}
1189
1190static inline int same_magic(const char *amagic, const char *bmagic,
1191 bool has_crcs)
1192{
1193 return strcmp(amagic, bmagic) == 0;
1194}
1195#endif /* CONFIG_MODVERSIONS */
1196
1197/* Resolve a symbol for this module. I.e. if we find one, record usage. */
1198static const struct kernel_symbol *resolve_symbol(struct module *mod,
1199 const struct load_info *info,
1200 const char *name,
1201 char ownername[])
1202{
1203 struct module *owner;
1204 const struct kernel_symbol *sym;
1205 const unsigned long *crc;
1206 int err;
1207
1208 mutex_lock(&module_mutex);
1209 sym = find_symbol(name, &owner, &crc,
1210 !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
1211 if (!sym)
1212 goto unlock;
1213
1214 if (!check_version(info->sechdrs, info->index.vers, name, mod, crc,
1215 owner)) {
1216 sym = ERR_PTR(-EINVAL);
1217 goto getname;
1218 }
1219
1220 err = ref_module(mod, owner);
1221 if (err) {
1222 sym = ERR_PTR(err);
1223 goto getname;
1224 }
1225
1226getname:
1227 /* We must make copy under the lock if we failed to get ref. */
1228 strncpy(ownername, module_name(owner), MODULE_NAME_LEN);
1229unlock:
1230 mutex_unlock(&module_mutex);
1231 return sym;
1232}
1233
1234static const struct kernel_symbol *
1235resolve_symbol_wait(struct module *mod,
1236 const struct load_info *info,
1237 const char *name)
1238{
1239 const struct kernel_symbol *ksym;
1240 char owner[MODULE_NAME_LEN];
1241
1242 if (wait_event_interruptible_timeout(module_wq,
1243 !IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
1244 || PTR_ERR(ksym) != -EBUSY,
1245 30 * HZ) <= 0) {
1246 printk(KERN_WARNING "%s: gave up waiting for init of module %s.\n",
1247 mod->name, owner);
1248 }
1249 return ksym;
1250}
1251
1252/*
1253 * /sys/module/foo/sections stuff
1254 * J. Corbet <corbet@lwn.net>
1255 */
1256#ifdef CONFIG_SYSFS
1257
1258#ifdef CONFIG_KALLSYMS
1259static inline bool sect_empty(const Elf_Shdr *sect)
1260{
1261 return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
1262}
1263
1264struct module_sect_attr
1265{
1266 struct module_attribute mattr;
1267 char *name;
1268 unsigned long address;
1269};
1270
1271struct module_sect_attrs
1272{
1273 struct attribute_group grp;
1274 unsigned int nsections;
1275 struct module_sect_attr attrs[0];
1276};
1277
1278static ssize_t module_sect_show(struct module_attribute *mattr,
1279 struct module_kobject *mk, char *buf)
1280{
1281 struct module_sect_attr *sattr =
1282 container_of(mattr, struct module_sect_attr, mattr);
1283 return sprintf(buf, "0x%pK\n", (void *)sattr->address);
1284}
1285
1286static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
1287{
1288 unsigned int section;
1289
1290 for (section = 0; section < sect_attrs->nsections; section++)
1291 kfree(sect_attrs->attrs[section].name);
1292 kfree(sect_attrs);
1293}
1294
1295static void add_sect_attrs(struct module *mod, const struct load_info *info)
1296{
1297 unsigned int nloaded = 0, i, size[2];
1298 struct module_sect_attrs *sect_attrs;
1299 struct module_sect_attr *sattr;
1300 struct attribute **gattr;
1301
1302 /* Count loaded sections and allocate structures */
1303 for (i = 0; i < info->hdr->e_shnum; i++)
1304 if (!sect_empty(&info->sechdrs[i]))
1305 nloaded++;
1306 size[0] = ALIGN(sizeof(*sect_attrs)
1307 + nloaded * sizeof(sect_attrs->attrs[0]),
1308 sizeof(sect_attrs->grp.attrs[0]));
1309 size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]);
1310 sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
1311 if (sect_attrs == NULL)
1312 return;
1313
1314 /* Setup section attributes. */
1315 sect_attrs->grp.name = "sections";
1316 sect_attrs->grp.attrs = (void *)sect_attrs + size[0];
1317
1318 sect_attrs->nsections = 0;
1319 sattr = §_attrs->attrs[0];
1320 gattr = §_attrs->grp.attrs[0];
1321 for (i = 0; i < info->hdr->e_shnum; i++) {
1322 Elf_Shdr *sec = &info->sechdrs[i];
1323 if (sect_empty(sec))
1324 continue;
1325 sattr->address = sec->sh_addr;
1326 sattr->name = kstrdup(info->secstrings + sec->sh_name,
1327 GFP_KERNEL);
1328 if (sattr->name == NULL)
1329 goto out;
1330 sect_attrs->nsections++;
1331 sysfs_attr_init(&sattr->mattr.attr);
1332 sattr->mattr.show = module_sect_show;
1333 sattr->mattr.store = NULL;
1334 sattr->mattr.attr.name = sattr->name;
1335 sattr->mattr.attr.mode = S_IRUGO;
1336 *(gattr++) = &(sattr++)->mattr.attr;
1337 }
1338 *gattr = NULL;
1339
1340 if (sysfs_create_group(&mod->mkobj.kobj, §_attrs->grp))
1341 goto out;
1342
1343 mod->sect_attrs = sect_attrs;
1344 return;
1345 out:
1346 free_sect_attrs(sect_attrs);
1347}
1348
1349static void remove_sect_attrs(struct module *mod)
1350{
1351 if (mod->sect_attrs) {
1352 sysfs_remove_group(&mod->mkobj.kobj,
1353 &mod->sect_attrs->grp);
1354 /* We are positive that no one is using any sect attrs
1355 * at this point. Deallocate immediately. */
1356 free_sect_attrs(mod->sect_attrs);
1357 mod->sect_attrs = NULL;
1358 }
1359}
1360
1361/*
1362 * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
1363 */
1364
1365struct module_notes_attrs {
1366 struct kobject *dir;
1367 unsigned int notes;
1368 struct bin_attribute attrs[0];
1369};
1370
1371static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
1372 struct bin_attribute *bin_attr,
1373 char *buf, loff_t pos, size_t count)
1374{
1375 /*
1376 * The caller checked the pos and count against our size.
1377 */
1378 memcpy(buf, bin_attr->private + pos, count);
1379 return count;
1380}
1381
1382static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
1383 unsigned int i)
1384{
1385 if (notes_attrs->dir) {
1386 while (i-- > 0)
1387 sysfs_remove_bin_file(notes_attrs->dir,
1388 ¬es_attrs->attrs[i]);
1389 kobject_put(notes_attrs->dir);
1390 }
1391 kfree(notes_attrs);
1392}
1393
1394static void add_notes_attrs(struct module *mod, const struct load_info *info)
1395{
1396 unsigned int notes, loaded, i;
1397 struct module_notes_attrs *notes_attrs;
1398 struct bin_attribute *nattr;
1399
1400 /* failed to create section attributes, so can't create notes */
1401 if (!mod->sect_attrs)
1402 return;
1403
1404 /* Count notes sections and allocate structures. */
1405 notes = 0;
1406 for (i = 0; i < info->hdr->e_shnum; i++)
1407 if (!sect_empty(&info->sechdrs[i]) &&
1408 (info->sechdrs[i].sh_type == SHT_NOTE))
1409 ++notes;
1410
1411 if (notes == 0)
1412 return;
1413
1414 notes_attrs = kzalloc(sizeof(*notes_attrs)
1415 + notes * sizeof(notes_attrs->attrs[0]),
1416 GFP_KERNEL);
1417 if (notes_attrs == NULL)
1418 return;
1419
1420 notes_attrs->notes = notes;
1421 nattr = ¬es_attrs->attrs[0];
1422 for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
1423 if (sect_empty(&info->sechdrs[i]))
1424 continue;
1425 if (info->sechdrs[i].sh_type == SHT_NOTE) {
1426 sysfs_bin_attr_init(nattr);
1427 nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
1428 nattr->attr.mode = S_IRUGO;
1429 nattr->size = info->sechdrs[i].sh_size;
1430 nattr->private = (void *) info->sechdrs[i].sh_addr;
1431 nattr->read = module_notes_read;
1432 ++nattr;
1433 }
1434 ++loaded;
1435 }
1436
1437 notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
1438 if (!notes_attrs->dir)
1439 goto out;
1440
1441 for (i = 0; i < notes; ++i)
1442 if (sysfs_create_bin_file(notes_attrs->dir,
1443 ¬es_attrs->attrs[i]))
1444 goto out;
1445
1446 mod->notes_attrs = notes_attrs;
1447 return;
1448
1449 out:
1450 free_notes_attrs(notes_attrs, i);
1451}
1452
1453static void remove_notes_attrs(struct module *mod)
1454{
1455 if (mod->notes_attrs)
1456 free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
1457}
1458
1459#else
1460
1461static inline void add_sect_attrs(struct module *mod,
1462 const struct load_info *info)
1463{
1464}
1465
1466static inline void remove_sect_attrs(struct module *mod)
1467{
1468}
1469
1470static inline void add_notes_attrs(struct module *mod,
1471 const struct load_info *info)
1472{
1473}
1474
1475static inline void remove_notes_attrs(struct module *mod)
1476{
1477}
1478#endif /* CONFIG_KALLSYMS */
1479
1480static void add_usage_links(struct module *mod)
1481{
1482#ifdef CONFIG_MODULE_UNLOAD
1483 struct module_use *use;
1484 int nowarn;
1485
1486 mutex_lock(&module_mutex);
1487 list_for_each_entry(use, &mod->target_list, target_list) {
1488 nowarn = sysfs_create_link(use->target->holders_dir,
1489 &mod->mkobj.kobj, mod->name);
1490 }
1491 mutex_unlock(&module_mutex);
1492#endif
1493}
1494
1495static void del_usage_links(struct module *mod)
1496{
1497#ifdef CONFIG_MODULE_UNLOAD
1498 struct module_use *use;
1499
1500 mutex_lock(&module_mutex);
1501 list_for_each_entry(use, &mod->target_list, target_list)
1502 sysfs_remove_link(use->target->holders_dir, mod->name);
1503 mutex_unlock(&module_mutex);
1504#endif
1505}
1506
1507static int module_add_modinfo_attrs(struct module *mod)
1508{
1509 struct module_attribute *attr;
1510 struct module_attribute *temp_attr;
1511 int error = 0;
1512 int i;
1513
1514 mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
1515 (ARRAY_SIZE(modinfo_attrs) + 1)),
1516 GFP_KERNEL);
1517 if (!mod->modinfo_attrs)
1518 return -ENOMEM;
1519
1520 temp_attr = mod->modinfo_attrs;
1521 for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
1522 if (!attr->test ||
1523 (attr->test && attr->test(mod))) {
1524 memcpy(temp_attr, attr, sizeof(*temp_attr));
1525 sysfs_attr_init(&temp_attr->attr);
1526 error = sysfs_create_file(&mod->mkobj.kobj,&temp_attr->attr);
1527 ++temp_attr;
1528 }
1529 }
1530 return error;
1531}
1532
1533static void module_remove_modinfo_attrs(struct module *mod)
1534{
1535 struct module_attribute *attr;
1536 int i;
1537
1538 for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
1539 /* pick a field to test for end of list */
1540 if (!attr->attr.name)
1541 break;
1542 sysfs_remove_file(&mod->mkobj.kobj,&attr->attr);
1543 if (attr->free)
1544 attr->free(mod);
1545 }
1546 kfree(mod->modinfo_attrs);
1547}
1548
1549static int mod_sysfs_init(struct module *mod)
1550{
1551 int err;
1552 struct kobject *kobj;
1553
1554 if (!module_sysfs_initialized) {
1555 printk(KERN_ERR "%s: module sysfs not initialized\n",
1556 mod->name);
1557 err = -EINVAL;
1558 goto out;
1559 }
1560
1561 kobj = kset_find_obj(module_kset, mod->name);
1562 if (kobj) {
1563 printk(KERN_ERR "%s: module is already loaded\n", mod->name);
1564 kobject_put(kobj);
1565 err = -EINVAL;
1566 goto out;
1567 }
1568
1569 mod->mkobj.mod = mod;
1570
1571 memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
1572 mod->mkobj.kobj.kset = module_kset;
1573 err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
1574 "%s", mod->name);
1575 if (err)
1576 kobject_put(&mod->mkobj.kobj);
1577
1578 /* delay uevent until full sysfs population */
1579out:
1580 return err;
1581}
1582
1583static int mod_sysfs_setup(struct module *mod,
1584 const struct load_info *info,
1585 struct kernel_param *kparam,
1586 unsigned int num_params)
1587{
1588 int err;
1589
1590 err = mod_sysfs_init(mod);
1591 if (err)
1592 goto out;
1593
1594 mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1595 if (!mod->holders_dir) {
1596 err = -ENOMEM;
1597 goto out_unreg;
1598 }
1599
1600 err = module_param_sysfs_setup(mod, kparam, num_params);
1601 if (err)
1602 goto out_unreg_holders;
1603
1604 err = module_add_modinfo_attrs(mod);
1605 if (err)
1606 goto out_unreg_param;
1607
1608 add_usage_links(mod);
1609 add_sect_attrs(mod, info);
1610 add_notes_attrs(mod, info);
1611
1612 kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
1613 return 0;
1614
1615out_unreg_param:
1616 module_param_sysfs_remove(mod);
1617out_unreg_holders:
1618 kobject_put(mod->holders_dir);
1619out_unreg:
1620 kobject_put(&mod->mkobj.kobj);
1621out:
1622 return err;
1623}
1624
1625static void mod_sysfs_fini(struct module *mod)
1626{
1627 remove_notes_attrs(mod);
1628 remove_sect_attrs(mod);
1629 kobject_put(&mod->mkobj.kobj);
1630}
1631
1632#else /* !CONFIG_SYSFS */
1633
1634static int mod_sysfs_setup(struct module *mod,
1635 const struct load_info *info,
1636 struct kernel_param *kparam,
1637 unsigned int num_params)
1638{
1639 return 0;
1640}
1641
1642static void mod_sysfs_fini(struct module *mod)
1643{
1644}
1645
1646static void module_remove_modinfo_attrs(struct module *mod)
1647{
1648}
1649
1650static void del_usage_links(struct module *mod)
1651{
1652}
1653
1654#endif /* CONFIG_SYSFS */
1655
1656static void mod_sysfs_teardown(struct module *mod)
1657{
1658 del_usage_links(mod);
1659 module_remove_modinfo_attrs(mod);
1660 module_param_sysfs_remove(mod);
1661 kobject_put(mod->mkobj.drivers_dir);
1662 kobject_put(mod->holders_dir);
1663 mod_sysfs_fini(mod);
1664}
1665
1666/*
1667 * unlink the module with the whole machine is stopped with interrupts off
1668 * - this defends against kallsyms not taking locks
1669 */
1670static int __unlink_module(void *_mod)
1671{
1672 struct module *mod = _mod;
1673 list_del(&mod->list);
1674 module_bug_cleanup(mod);
1675 return 0;
1676}
1677
1678#ifdef CONFIG_DEBUG_SET_MODULE_RONX
1679/*
1680 * LKM RO/NX protection: protect module's text/ro-data
1681 * from modification and any data from execution.
1682 */
1683void set_page_attributes(void *start, void *end, int (*set)(unsigned long start, int num_pages))
1684{
1685 unsigned long begin_pfn = PFN_DOWN((unsigned long)start);
1686 unsigned long end_pfn = PFN_DOWN((unsigned long)end);
1687
1688 if (end_pfn > begin_pfn)
1689 set(begin_pfn << PAGE_SHIFT, end_pfn - begin_pfn);
1690}
1691
1692static void set_section_ro_nx(void *base,
1693 unsigned long text_size,
1694 unsigned long ro_size,
1695 unsigned long total_size)
1696{
1697 /* begin and end PFNs of the current subsection */
1698 unsigned long begin_pfn;
1699 unsigned long end_pfn;
1700
1701 /*
1702 * Set RO for module text and RO-data:
1703 * - Always protect first page.
1704 * - Do not protect last partial page.
1705 */
1706 if (ro_size > 0)
1707 set_page_attributes(base, base + ro_size, set_memory_ro);
1708
1709 /*
1710 * Set NX permissions for module data:
1711 * - Do not protect first partial page.
1712 * - Always protect last page.
1713 */
1714 if (total_size > text_size) {
1715 begin_pfn = PFN_UP((unsigned long)base + text_size);
1716 end_pfn = PFN_UP((unsigned long)base + total_size);
1717 if (end_pfn > begin_pfn)
1718 set_memory_nx(begin_pfn << PAGE_SHIFT, end_pfn - begin_pfn);
1719 }
1720}
1721
1722static void unset_module_core_ro_nx(struct module *mod)
1723{
1724 set_page_attributes(mod->module_core + mod->core_text_size,
1725 mod->module_core + mod->core_size,
1726 set_memory_x);
1727 set_page_attributes(mod->module_core,
1728 mod->module_core + mod->core_ro_size,
1729 set_memory_rw);
1730}
1731
1732static void unset_module_init_ro_nx(struct module *mod)
1733{
1734 set_page_attributes(mod->module_init + mod->init_text_size,
1735 mod->module_init + mod->init_size,
1736 set_memory_x);
1737 set_page_attributes(mod->module_init,
1738 mod->module_init + mod->init_ro_size,
1739 set_memory_rw);
1740}
1741
1742/* Iterate through all modules and set each module's text as RW */
1743void set_all_modules_text_rw(void)
1744{
1745 struct module *mod;
1746
1747 mutex_lock(&module_mutex);
1748 list_for_each_entry_rcu(mod, &modules, list) {
1749 if ((mod->module_core) && (mod->core_text_size)) {
1750 set_page_attributes(mod->module_core,
1751 mod->module_core + mod->core_text_size,
1752 set_memory_rw);
1753 }
1754 if ((mod->module_init) && (mod->init_text_size)) {
1755 set_page_attributes(mod->module_init,
1756 mod->module_init + mod->init_text_size,
1757 set_memory_rw);
1758 }
1759 }
1760 mutex_unlock(&module_mutex);
1761}
1762
1763/* Iterate through all modules and set each module's text as RO */
1764void set_all_modules_text_ro(void)
1765{
1766 struct module *mod;
1767
1768 mutex_lock(&module_mutex);
1769 list_for_each_entry_rcu(mod, &modules, list) {
1770 if ((mod->module_core) && (mod->core_text_size)) {
1771 set_page_attributes(mod->module_core,
1772 mod->module_core + mod->core_text_size,
1773 set_memory_ro);
1774 }
1775 if ((mod->module_init) && (mod->init_text_size)) {
1776 set_page_attributes(mod->module_init,
1777 mod->module_init + mod->init_text_size,
1778 set_memory_ro);
1779 }
1780 }
1781 mutex_unlock(&module_mutex);
1782}
1783#else
1784static inline void set_section_ro_nx(void *base, unsigned long text_size, unsigned long ro_size, unsigned long total_size) { }
1785static void unset_module_core_ro_nx(struct module *mod) { }
1786static void unset_module_init_ro_nx(struct module *mod) { }
1787#endif
1788
1789void __weak module_free(struct module *mod, void *module_region)
1790{
1791 vfree(module_region);
1792}
1793
1794void __weak module_arch_cleanup(struct module *mod)
1795{
1796}
1797
1798/* Free a module, remove from lists, etc. */
1799static void free_module(struct module *mod)
1800{
1801 trace_module_free(mod);
1802
1803 /* Delete from various lists */
1804 mutex_lock(&module_mutex);
1805 stop_machine(__unlink_module, mod, NULL);
1806 mutex_unlock(&module_mutex);
1807 mod_sysfs_teardown(mod);
1808
1809 /* Remove dynamic debug info */
1810 ddebug_remove_module(mod->name);
1811
1812 /* Arch-specific cleanup. */
1813 module_arch_cleanup(mod);
1814
1815 /* Module unload stuff */
1816 module_unload_free(mod);
1817
1818 /* Free any allocated parameters. */
1819 destroy_params(mod->kp, mod->num_kp);
1820
1821 /* This may be NULL, but that's OK */
1822 unset_module_init_ro_nx(mod);
1823 module_free(mod, mod->module_init);
1824 kfree(mod->args);
1825 percpu_modfree(mod);
1826
1827 /* Free lock-classes: */
1828 lockdep_free_key_range(mod->module_core, mod->core_size);
1829
1830 /* Finally, free the core (containing the module structure) */
1831 unset_module_core_ro_nx(mod);
1832 module_free(mod, mod->module_core);
1833
1834#ifdef CONFIG_MPU
1835 update_protections(current->mm);
1836#endif
1837}
1838
1839void *__symbol_get(const char *symbol)
1840{
1841 struct module *owner;
1842 const struct kernel_symbol *sym;
1843
1844 preempt_disable();
1845 sym = find_symbol(symbol, &owner, NULL, true, true);
1846 if (sym && strong_try_module_get(owner))
1847 sym = NULL;
1848 preempt_enable();
1849
1850 return sym ? (void *)sym->value : NULL;
1851}
1852EXPORT_SYMBOL_GPL(__symbol_get);
1853
1854/*
1855 * Ensure that an exported symbol [global namespace] does not already exist
1856 * in the kernel or in some other module's exported symbol table.
1857 *
1858 * You must hold the module_mutex.
1859 */
1860static int verify_export_symbols(struct module *mod)
1861{
1862 unsigned int i;
1863 struct module *owner;
1864 const struct kernel_symbol *s;
1865 struct {
1866 const struct kernel_symbol *sym;
1867 unsigned int num;
1868 } arr[] = {
1869 { mod->syms, mod->num_syms },
1870 { mod->gpl_syms, mod->num_gpl_syms },
1871 { mod->gpl_future_syms, mod->num_gpl_future_syms },
1872#ifdef CONFIG_UNUSED_SYMBOLS
1873 { mod->unused_syms, mod->num_unused_syms },
1874 { mod->unused_gpl_syms, mod->num_unused_gpl_syms },
1875#endif
1876 };
1877
1878 for (i = 0; i < ARRAY_SIZE(arr); i++) {
1879 for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
1880 if (find_symbol(s->name, &owner, NULL, true, false)) {
1881 printk(KERN_ERR
1882 "%s: exports duplicate symbol %s"
1883 " (owned by %s)\n",
1884 mod->name, s->name, module_name(owner));
1885 return -ENOEXEC;
1886 }
1887 }
1888 }
1889 return 0;
1890}
1891
1892/* Change all symbols so that st_value encodes the pointer directly. */
1893static int simplify_symbols(struct module *mod, const struct load_info *info)
1894{
1895 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
1896 Elf_Sym *sym = (void *)symsec->sh_addr;
1897 unsigned long secbase;
1898 unsigned int i;
1899 int ret = 0;
1900 const struct kernel_symbol *ksym;
1901
1902 for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
1903 const char *name = info->strtab + sym[i].st_name;
1904
1905 switch (sym[i].st_shndx) {
1906 case SHN_COMMON:
1907 /* We compiled with -fno-common. These are not
1908 supposed to happen. */
1909 pr_debug("Common symbol: %s\n", name);
1910 printk("%s: please compile with -fno-common\n",
1911 mod->name);
1912 ret = -ENOEXEC;
1913 break;
1914
1915 case SHN_ABS:
1916 /* Don't need to do anything */
1917 pr_debug("Absolute symbol: 0x%08lx\n",
1918 (long)sym[i].st_value);
1919 break;
1920
1921 case SHN_UNDEF:
1922 ksym = resolve_symbol_wait(mod, info, name);
1923 /* Ok if resolved. */
1924 if (ksym && !IS_ERR(ksym)) {
1925 sym[i].st_value = ksym->value;
1926 break;
1927 }
1928
1929 /* Ok if weak. */
1930 if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
1931 break;
1932
1933 printk(KERN_WARNING "%s: Unknown symbol %s (err %li)\n",
1934 mod->name, name, PTR_ERR(ksym));
1935 ret = PTR_ERR(ksym) ?: -ENOENT;
1936 break;
1937
1938 default:
1939 /* Divert to percpu allocation if a percpu var. */
1940 if (sym[i].st_shndx == info->index.pcpu)
1941 secbase = (unsigned long)mod_percpu(mod);
1942 else
1943 secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
1944 sym[i].st_value += secbase;
1945 break;
1946 }
1947 }
1948
1949 return ret;
1950}
1951
1952int __weak apply_relocate(Elf_Shdr *sechdrs,
1953 const char *strtab,
1954 unsigned int symindex,
1955 unsigned int relsec,
1956 struct module *me)
1957{
1958 pr_err("module %s: REL relocation unsupported\n", me->name);
1959 return -ENOEXEC;
1960}
1961
1962int __weak apply_relocate_add(Elf_Shdr *sechdrs,
1963 const char *strtab,
1964 unsigned int symindex,
1965 unsigned int relsec,
1966 struct module *me)
1967{
1968 pr_err("module %s: RELA relocation unsupported\n", me->name);
1969 return -ENOEXEC;
1970}
1971
1972static int apply_relocations(struct module *mod, const struct load_info *info)
1973{
1974 unsigned int i;
1975 int err = 0;
1976
1977 /* Now do relocations. */
1978 for (i = 1; i < info->hdr->e_shnum; i++) {
1979 unsigned int infosec = info->sechdrs[i].sh_info;
1980
1981 /* Not a valid relocation section? */
1982 if (infosec >= info->hdr->e_shnum)
1983 continue;
1984
1985 /* Don't bother with non-allocated sections */
1986 if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
1987 continue;
1988
1989 if (info->sechdrs[i].sh_type == SHT_REL)
1990 err = apply_relocate(info->sechdrs, info->strtab,
1991 info->index.sym, i, mod);
1992 else if (info->sechdrs[i].sh_type == SHT_RELA)
1993 err = apply_relocate_add(info->sechdrs, info->strtab,
1994 info->index.sym, i, mod);
1995 if (err < 0)
1996 break;
1997 }
1998 return err;
1999}
2000
2001/* Additional bytes needed by arch in front of individual sections */
2002unsigned int __weak arch_mod_section_prepend(struct module *mod,
2003 unsigned int section)
2004{
2005 /* default implementation just returns zero */
2006 return 0;
2007}
2008
2009/* Update size with this section: return offset. */
2010static long get_offset(struct module *mod, unsigned int *size,
2011 Elf_Shdr *sechdr, unsigned int section)
2012{
2013 long ret;
2014
2015 *size += arch_mod_section_prepend(mod, section);
2016 ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
2017 *size = ret + sechdr->sh_size;
2018 return ret;
2019}
2020
2021/* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
2022 might -- code, read-only data, read-write data, small data. Tally
2023 sizes, and place the offsets into sh_entsize fields: high bit means it
2024 belongs in init. */
2025static void layout_sections(struct module *mod, struct load_info *info)
2026{
2027 static unsigned long const masks[][2] = {
2028 /* NOTE: all executable code must be the first section
2029 * in this array; otherwise modify the text_size
2030 * finder in the two loops below */
2031 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
2032 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
2033 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
2034 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
2035 };
2036 unsigned int m, i;
2037
2038 for (i = 0; i < info->hdr->e_shnum; i++)
2039 info->sechdrs[i].sh_entsize = ~0UL;
2040
2041 pr_debug("Core section allocation order:\n");
2042 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2043 for (i = 0; i < info->hdr->e_shnum; ++i) {
2044 Elf_Shdr *s = &info->sechdrs[i];
2045 const char *sname = info->secstrings + s->sh_name;
2046
2047 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2048 || (s->sh_flags & masks[m][1])
2049 || s->sh_entsize != ~0UL
2050 || strstarts(sname, ".init"))
2051 continue;
2052 s->sh_entsize = get_offset(mod, &mod->core_size, s, i);
2053 pr_debug("\t%s\n", sname);
2054 }
2055 switch (m) {
2056 case 0: /* executable */
2057 mod->core_size = debug_align(mod->core_size);
2058 mod->core_text_size = mod->core_size;
2059 break;
2060 case 1: /* RO: text and ro-data */
2061 mod->core_size = debug_align(mod->core_size);
2062 mod->core_ro_size = mod->core_size;
2063 break;
2064 case 3: /* whole core */
2065 mod->core_size = debug_align(mod->core_size);
2066 break;
2067 }
2068 }
2069
2070 pr_debug("Init section allocation order:\n");
2071 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2072 for (i = 0; i < info->hdr->e_shnum; ++i) {
2073 Elf_Shdr *s = &info->sechdrs[i];
2074 const char *sname = info->secstrings + s->sh_name;
2075
2076 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2077 || (s->sh_flags & masks[m][1])
2078 || s->sh_entsize != ~0UL
2079 || !strstarts(sname, ".init"))
2080 continue;
2081 s->sh_entsize = (get_offset(mod, &mod->init_size, s, i)
2082 | INIT_OFFSET_MASK);
2083 pr_debug("\t%s\n", sname);
2084 }
2085 switch (m) {
2086 case 0: /* executable */
2087 mod->init_size = debug_align(mod->init_size);
2088 mod->init_text_size = mod->init_size;
2089 break;
2090 case 1: /* RO: text and ro-data */
2091 mod->init_size = debug_align(mod->init_size);
2092 mod->init_ro_size = mod->init_size;
2093 break;
2094 case 3: /* whole init */
2095 mod->init_size = debug_align(mod->init_size);
2096 break;
2097 }
2098 }
2099}
2100
2101static void set_license(struct module *mod, const char *license)
2102{
2103 if (!license)
2104 license = "unspecified";
2105
2106 if (!license_is_gpl_compatible(license)) {
2107 if (!test_taint(TAINT_PROPRIETARY_MODULE))
2108 printk(KERN_WARNING "%s: module license '%s' taints "
2109 "kernel.\n", mod->name, license);
2110 add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
2111 }
2112}
2113
2114/* Parse tag=value strings from .modinfo section */
2115static char *next_string(char *string, unsigned long *secsize)
2116{
2117 /* Skip non-zero chars */
2118 while (string[0]) {
2119 string++;
2120 if ((*secsize)-- <= 1)
2121 return NULL;
2122 }
2123
2124 /* Skip any zero padding. */
2125 while (!string[0]) {
2126 string++;
2127 if ((*secsize)-- <= 1)
2128 return NULL;
2129 }
2130 return string;
2131}
2132
2133static char *get_modinfo(struct load_info *info, const char *tag)
2134{
2135 char *p;
2136 unsigned int taglen = strlen(tag);
2137 Elf_Shdr *infosec = &info->sechdrs[info->index.info];
2138 unsigned long size = infosec->sh_size;
2139
2140 for (p = (char *)infosec->sh_addr; p; p = next_string(p, &size)) {
2141 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
2142 return p + taglen + 1;
2143 }
2144 return NULL;
2145}
2146
2147static void setup_modinfo(struct module *mod, struct load_info *info)
2148{
2149 struct module_attribute *attr;
2150 int i;
2151
2152 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2153 if (attr->setup)
2154 attr->setup(mod, get_modinfo(info, attr->attr.name));
2155 }
2156}
2157
2158static void free_modinfo(struct module *mod)
2159{
2160 struct module_attribute *attr;
2161 int i;
2162
2163 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2164 if (attr->free)
2165 attr->free(mod);
2166 }
2167}
2168
2169#ifdef CONFIG_KALLSYMS
2170
2171/* lookup symbol in given range of kernel_symbols */
2172static const struct kernel_symbol *lookup_symbol(const char *name,
2173 const struct kernel_symbol *start,
2174 const struct kernel_symbol *stop)
2175{
2176 return bsearch(name, start, stop - start,
2177 sizeof(struct kernel_symbol), cmp_name);
2178}
2179
2180static int is_exported(const char *name, unsigned long value,
2181 const struct module *mod)
2182{
2183 const struct kernel_symbol *ks;
2184 if (!mod)
2185 ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
2186 else
2187 ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
2188 return ks != NULL && ks->value == value;
2189}
2190
2191/* As per nm */
2192static char elf_type(const Elf_Sym *sym, const struct load_info *info)
2193{
2194 const Elf_Shdr *sechdrs = info->sechdrs;
2195
2196 if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
2197 if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
2198 return 'v';
2199 else
2200 return 'w';
2201 }
2202 if (sym->st_shndx == SHN_UNDEF)
2203 return 'U';
2204 if (sym->st_shndx == SHN_ABS)
2205 return 'a';
2206 if (sym->st_shndx >= SHN_LORESERVE)
2207 return '?';
2208 if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
2209 return 't';
2210 if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
2211 && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
2212 if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
2213 return 'r';
2214 else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2215 return 'g';
2216 else
2217 return 'd';
2218 }
2219 if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
2220 if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2221 return 's';
2222 else
2223 return 'b';
2224 }
2225 if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
2226 ".debug")) {
2227 return 'n';
2228 }
2229 return '?';
2230}
2231
2232static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
2233 unsigned int shnum)
2234{
2235 const Elf_Shdr *sec;
2236
2237 if (src->st_shndx == SHN_UNDEF
2238 || src->st_shndx >= shnum
2239 || !src->st_name)
2240 return false;
2241
2242 sec = sechdrs + src->st_shndx;
2243 if (!(sec->sh_flags & SHF_ALLOC)
2244#ifndef CONFIG_KALLSYMS_ALL
2245 || !(sec->sh_flags & SHF_EXECINSTR)
2246#endif
2247 || (sec->sh_entsize & INIT_OFFSET_MASK))
2248 return false;
2249
2250 return true;
2251}
2252
2253/*
2254 * We only allocate and copy the strings needed by the parts of symtab
2255 * we keep. This is simple, but has the effect of making multiple
2256 * copies of duplicates. We could be more sophisticated, see
2257 * linux-kernel thread starting with
2258 * <73defb5e4bca04a6431392cc341112b1@localhost>.
2259 */
2260static void layout_symtab(struct module *mod, struct load_info *info)
2261{
2262 Elf_Shdr *symsect = info->sechdrs + info->index.sym;
2263 Elf_Shdr *strsect = info->sechdrs + info->index.str;
2264 const Elf_Sym *src;
2265 unsigned int i, nsrc, ndst, strtab_size;
2266
2267 /* Put symbol section at end of init part of module. */
2268 symsect->sh_flags |= SHF_ALLOC;
2269 symsect->sh_entsize = get_offset(mod, &mod->init_size, symsect,
2270 info->index.sym) | INIT_OFFSET_MASK;
2271 pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
2272
2273 src = (void *)info->hdr + symsect->sh_offset;
2274 nsrc = symsect->sh_size / sizeof(*src);
2275
2276 /* Compute total space required for the core symbols' strtab. */
2277 for (ndst = i = strtab_size = 1; i < nsrc; ++i, ++src)
2278 if (is_core_symbol(src, info->sechdrs, info->hdr->e_shnum)) {
2279 strtab_size += strlen(&info->strtab[src->st_name]) + 1;
2280 ndst++;
2281 }
2282
2283 /* Append room for core symbols at end of core part. */
2284 info->symoffs = ALIGN(mod->core_size, symsect->sh_addralign ?: 1);
2285 info->stroffs = mod->core_size = info->symoffs + ndst * sizeof(Elf_Sym);
2286 mod->core_size += strtab_size;
2287
2288 /* Put string table section at end of init part of module. */
2289 strsect->sh_flags |= SHF_ALLOC;
2290 strsect->sh_entsize = get_offset(mod, &mod->init_size, strsect,
2291 info->index.str) | INIT_OFFSET_MASK;
2292 pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
2293}
2294
2295static void add_kallsyms(struct module *mod, const struct load_info *info)
2296{
2297 unsigned int i, ndst;
2298 const Elf_Sym *src;
2299 Elf_Sym *dst;
2300 char *s;
2301 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2302
2303 mod->symtab = (void *)symsec->sh_addr;
2304 mod->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
2305 /* Make sure we get permanent strtab: don't use info->strtab. */
2306 mod->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
2307
2308 /* Set types up while we still have access to sections. */
2309 for (i = 0; i < mod->num_symtab; i++)
2310 mod->symtab[i].st_info = elf_type(&mod->symtab[i], info);
2311
2312 mod->core_symtab = dst = mod->module_core + info->symoffs;
2313 mod->core_strtab = s = mod->module_core + info->stroffs;
2314 src = mod->symtab;
2315 *dst = *src;
2316 *s++ = 0;
2317 for (ndst = i = 1; i < mod->num_symtab; ++i, ++src) {
2318 if (!is_core_symbol(src, info->sechdrs, info->hdr->e_shnum))
2319 continue;
2320
2321 dst[ndst] = *src;
2322 dst[ndst++].st_name = s - mod->core_strtab;
2323 s += strlcpy(s, &mod->strtab[src->st_name], KSYM_NAME_LEN) + 1;
2324 }
2325 mod->core_num_syms = ndst;
2326}
2327#else
2328static inline void layout_symtab(struct module *mod, struct load_info *info)
2329{
2330}
2331
2332static void add_kallsyms(struct module *mod, const struct load_info *info)
2333{
2334}
2335#endif /* CONFIG_KALLSYMS */
2336
2337static void dynamic_debug_setup(struct _ddebug *debug, unsigned int num)
2338{
2339 if (!debug)
2340 return;
2341#ifdef CONFIG_DYNAMIC_DEBUG
2342 if (ddebug_add_module(debug, num, debug->modname))
2343 printk(KERN_ERR "dynamic debug error adding module: %s\n",
2344 debug->modname);
2345#endif
2346}
2347
2348static void dynamic_debug_remove(struct _ddebug *debug)
2349{
2350 if (debug)
2351 ddebug_remove_module(debug->modname);
2352}
2353
2354void * __weak module_alloc(unsigned long size)
2355{
2356 return size == 0 ? NULL : vmalloc_exec(size);
2357}
2358
2359static void *module_alloc_update_bounds(unsigned long size)
2360{
2361 void *ret = module_alloc(size);
2362
2363 if (ret) {
2364 mutex_lock(&module_mutex);
2365 /* Update module bounds. */
2366 if ((unsigned long)ret < module_addr_min)
2367 module_addr_min = (unsigned long)ret;
2368 if ((unsigned long)ret + size > module_addr_max)
2369 module_addr_max = (unsigned long)ret + size;
2370 mutex_unlock(&module_mutex);
2371 }
2372 return ret;
2373}
2374
2375#ifdef CONFIG_DEBUG_KMEMLEAK
2376static void kmemleak_load_module(const struct module *mod,
2377 const struct load_info *info)
2378{
2379 unsigned int i;
2380
2381 /* only scan the sections containing data */
2382 kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
2383
2384 for (i = 1; i < info->hdr->e_shnum; i++) {
2385 const char *name = info->secstrings + info->sechdrs[i].sh_name;
2386 if (!(info->sechdrs[i].sh_flags & SHF_ALLOC))
2387 continue;
2388 if (!strstarts(name, ".data") && !strstarts(name, ".bss"))
2389 continue;
2390
2391 kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
2392 info->sechdrs[i].sh_size, GFP_KERNEL);
2393 }
2394}
2395#else
2396static inline void kmemleak_load_module(const struct module *mod,
2397 const struct load_info *info)
2398{
2399}
2400#endif
2401
2402/* Sets info->hdr and info->len. */
2403static int copy_and_check(struct load_info *info,
2404 const void __user *umod, unsigned long len,
2405 const char __user *uargs)
2406{
2407 int err;
2408 Elf_Ehdr *hdr;
2409
2410 if (len < sizeof(*hdr))
2411 return -ENOEXEC;
2412
2413 /* Suck in entire file: we'll want most of it. */
2414 if ((hdr = vmalloc(len)) == NULL)
2415 return -ENOMEM;
2416
2417 if (copy_from_user(hdr, umod, len) != 0) {
2418 err = -EFAULT;
2419 goto free_hdr;
2420 }
2421
2422 /* Sanity checks against insmoding binaries or wrong arch,
2423 weird elf version */
2424 if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0
2425 || hdr->e_type != ET_REL
2426 || !elf_check_arch(hdr)
2427 || hdr->e_shentsize != sizeof(Elf_Shdr)) {
2428 err = -ENOEXEC;
2429 goto free_hdr;
2430 }
2431
2432 if (hdr->e_shoff >= len ||
2433 hdr->e_shnum * sizeof(Elf_Shdr) > len - hdr->e_shoff) {
2434 err = -ENOEXEC;
2435 goto free_hdr;
2436 }
2437
2438 info->hdr = hdr;
2439 info->len = len;
2440 return 0;
2441
2442free_hdr:
2443 vfree(hdr);
2444 return err;
2445}
2446
2447static void free_copy(struct load_info *info)
2448{
2449 vfree(info->hdr);
2450}
2451
2452static int rewrite_section_headers(struct load_info *info)
2453{
2454 unsigned int i;
2455
2456 /* This should always be true, but let's be sure. */
2457 info->sechdrs[0].sh_addr = 0;
2458
2459 for (i = 1; i < info->hdr->e_shnum; i++) {
2460 Elf_Shdr *shdr = &info->sechdrs[i];
2461 if (shdr->sh_type != SHT_NOBITS
2462 && info->len < shdr->sh_offset + shdr->sh_size) {
2463 printk(KERN_ERR "Module len %lu truncated\n",
2464 info->len);
2465 return -ENOEXEC;
2466 }
2467
2468 /* Mark all sections sh_addr with their address in the
2469 temporary image. */
2470 shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
2471
2472#ifndef CONFIG_MODULE_UNLOAD
2473 /* Don't load .exit sections */
2474 if (strstarts(info->secstrings+shdr->sh_name, ".exit"))
2475 shdr->sh_flags &= ~(unsigned long)SHF_ALLOC;
2476#endif
2477 }
2478
2479 /* Track but don't keep modinfo and version sections. */
2480 info->index.vers = find_sec(info, "__versions");
2481 info->index.info = find_sec(info, ".modinfo");
2482 info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
2483 info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
2484 return 0;
2485}
2486
2487/*
2488 * Set up our basic convenience variables (pointers to section headers,
2489 * search for module section index etc), and do some basic section
2490 * verification.
2491 *
2492 * Return the temporary module pointer (we'll replace it with the final
2493 * one when we move the module sections around).
2494 */
2495static struct module *setup_load_info(struct load_info *info)
2496{
2497 unsigned int i;
2498 int err;
2499 struct module *mod;
2500
2501 /* Set up the convenience variables */
2502 info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
2503 info->secstrings = (void *)info->hdr
2504 + info->sechdrs[info->hdr->e_shstrndx].sh_offset;
2505
2506 err = rewrite_section_headers(info);
2507 if (err)
2508 return ERR_PTR(err);
2509
2510 /* Find internal symbols and strings. */
2511 for (i = 1; i < info->hdr->e_shnum; i++) {
2512 if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
2513 info->index.sym = i;
2514 info->index.str = info->sechdrs[i].sh_link;
2515 info->strtab = (char *)info->hdr
2516 + info->sechdrs[info->index.str].sh_offset;
2517 break;
2518 }
2519 }
2520
2521 info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
2522 if (!info->index.mod) {
2523 printk(KERN_WARNING "No module found in object\n");
2524 return ERR_PTR(-ENOEXEC);
2525 }
2526 /* This is temporary: point mod into copy of data. */
2527 mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2528
2529 if (info->index.sym == 0) {
2530 printk(KERN_WARNING "%s: module has no symbols (stripped?)\n",
2531 mod->name);
2532 return ERR_PTR(-ENOEXEC);
2533 }
2534
2535 info->index.pcpu = find_pcpusec(info);
2536
2537 /* Check module struct version now, before we try to use module. */
2538 if (!check_modstruct_version(info->sechdrs, info->index.vers, mod))
2539 return ERR_PTR(-ENOEXEC);
2540
2541 return mod;
2542}
2543
2544static int check_modinfo(struct module *mod, struct load_info *info)
2545{
2546 const char *modmagic = get_modinfo(info, "vermagic");
2547 int err;
2548
2549 /* This is allowed: modprobe --force will invalidate it. */
2550 if (!modmagic) {
2551 err = try_to_force_load(mod, "bad vermagic");
2552 if (err)
2553 return err;
2554 } else if (!same_magic(modmagic, vermagic, info->index.vers)) {
2555 printk(KERN_ERR "%s: version magic '%s' should be '%s'\n",
2556 mod->name, modmagic, vermagic);
2557 return -ENOEXEC;
2558 }
2559
2560 if (!get_modinfo(info, "intree"))
2561 add_taint_module(mod, TAINT_OOT_MODULE);
2562
2563 if (get_modinfo(info, "staging")) {
2564 add_taint_module(mod, TAINT_CRAP);
2565 printk(KERN_WARNING "%s: module is from the staging directory,"
2566 " the quality is unknown, you have been warned.\n",
2567 mod->name);
2568 }
2569
2570 /* Set up license info based on the info section */
2571 set_license(mod, get_modinfo(info, "license"));
2572
2573 return 0;
2574}
2575
2576static void find_module_sections(struct module *mod, struct load_info *info)
2577{
2578 mod->kp = section_objs(info, "__param",
2579 sizeof(*mod->kp), &mod->num_kp);
2580 mod->syms = section_objs(info, "__ksymtab",
2581 sizeof(*mod->syms), &mod->num_syms);
2582 mod->crcs = section_addr(info, "__kcrctab");
2583 mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
2584 sizeof(*mod->gpl_syms),
2585 &mod->num_gpl_syms);
2586 mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
2587 mod->gpl_future_syms = section_objs(info,
2588 "__ksymtab_gpl_future",
2589 sizeof(*mod->gpl_future_syms),
2590 &mod->num_gpl_future_syms);
2591 mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future");
2592
2593#ifdef CONFIG_UNUSED_SYMBOLS
2594 mod->unused_syms = section_objs(info, "__ksymtab_unused",
2595 sizeof(*mod->unused_syms),
2596 &mod->num_unused_syms);
2597 mod->unused_crcs = section_addr(info, "__kcrctab_unused");
2598 mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl",
2599 sizeof(*mod->unused_gpl_syms),
2600 &mod->num_unused_gpl_syms);
2601 mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl");
2602#endif
2603#ifdef CONFIG_CONSTRUCTORS
2604 mod->ctors = section_objs(info, ".ctors",
2605 sizeof(*mod->ctors), &mod->num_ctors);
2606#endif
2607
2608#ifdef CONFIG_TRACEPOINTS
2609 mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
2610 sizeof(*mod->tracepoints_ptrs),
2611 &mod->num_tracepoints);
2612#endif
2613#ifdef HAVE_JUMP_LABEL
2614 mod->jump_entries = section_objs(info, "__jump_table",
2615 sizeof(*mod->jump_entries),
2616 &mod->num_jump_entries);
2617#endif
2618#ifdef CONFIG_EVENT_TRACING
2619 mod->trace_events = section_objs(info, "_ftrace_events",
2620 sizeof(*mod->trace_events),
2621 &mod->num_trace_events);
2622 /*
2623 * This section contains pointers to allocated objects in the trace
2624 * code and not scanning it leads to false positives.
2625 */
2626 kmemleak_scan_area(mod->trace_events, sizeof(*mod->trace_events) *
2627 mod->num_trace_events, GFP_KERNEL);
2628#endif
2629#ifdef CONFIG_TRACING
2630 mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
2631 sizeof(*mod->trace_bprintk_fmt_start),
2632 &mod->num_trace_bprintk_fmt);
2633 /*
2634 * This section contains pointers to allocated objects in the trace
2635 * code and not scanning it leads to false positives.
2636 */
2637 kmemleak_scan_area(mod->trace_bprintk_fmt_start,
2638 sizeof(*mod->trace_bprintk_fmt_start) *
2639 mod->num_trace_bprintk_fmt, GFP_KERNEL);
2640#endif
2641#ifdef CONFIG_FTRACE_MCOUNT_RECORD
2642 /* sechdrs[0].sh_size is always zero */
2643 mod->ftrace_callsites = section_objs(info, "__mcount_loc",
2644 sizeof(*mod->ftrace_callsites),
2645 &mod->num_ftrace_callsites);
2646#endif
2647
2648 mod->extable = section_objs(info, "__ex_table",
2649 sizeof(*mod->extable), &mod->num_exentries);
2650
2651 if (section_addr(info, "__obsparm"))
2652 printk(KERN_WARNING "%s: Ignoring obsolete parameters\n",
2653 mod->name);
2654
2655 info->debug = section_objs(info, "__verbose",
2656 sizeof(*info->debug), &info->num_debug);
2657}
2658
2659static int move_module(struct module *mod, struct load_info *info)
2660{
2661 int i;
2662 void *ptr;
2663
2664 /* Do the allocs. */
2665 ptr = module_alloc_update_bounds(mod->core_size);
2666 /*
2667 * The pointer to this block is stored in the module structure
2668 * which is inside the block. Just mark it as not being a
2669 * leak.
2670 */
2671 kmemleak_not_leak(ptr);
2672 if (!ptr)
2673 return -ENOMEM;
2674
2675 memset(ptr, 0, mod->core_size);
2676 mod->module_core = ptr;
2677
2678 ptr = module_alloc_update_bounds(mod->init_size);
2679 /*
2680 * The pointer to this block is stored in the module structure
2681 * which is inside the block. This block doesn't need to be
2682 * scanned as it contains data and code that will be freed
2683 * after the module is initialized.
2684 */
2685 kmemleak_ignore(ptr);
2686 if (!ptr && mod->init_size) {
2687 module_free(mod, mod->module_core);
2688 return -ENOMEM;
2689 }
2690 memset(ptr, 0, mod->init_size);
2691 mod->module_init = ptr;
2692
2693 /* Transfer each section which specifies SHF_ALLOC */
2694 pr_debug("final section addresses:\n");
2695 for (i = 0; i < info->hdr->e_shnum; i++) {
2696 void *dest;
2697 Elf_Shdr *shdr = &info->sechdrs[i];
2698
2699 if (!(shdr->sh_flags & SHF_ALLOC))
2700 continue;
2701
2702 if (shdr->sh_entsize & INIT_OFFSET_MASK)
2703 dest = mod->module_init
2704 + (shdr->sh_entsize & ~INIT_OFFSET_MASK);
2705 else
2706 dest = mod->module_core + shdr->sh_entsize;
2707
2708 if (shdr->sh_type != SHT_NOBITS)
2709 memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
2710 /* Update sh_addr to point to copy in image. */
2711 shdr->sh_addr = (unsigned long)dest;
2712 pr_debug("\t0x%lx %s\n",
2713 (long)shdr->sh_addr, info->secstrings + shdr->sh_name);
2714 }
2715
2716 return 0;
2717}
2718
2719static int check_module_license_and_versions(struct module *mod)
2720{
2721 /*
2722 * ndiswrapper is under GPL by itself, but loads proprietary modules.
2723 * Don't use add_taint_module(), as it would prevent ndiswrapper from
2724 * using GPL-only symbols it needs.
2725 */
2726 if (strcmp(mod->name, "ndiswrapper") == 0)
2727 add_taint(TAINT_PROPRIETARY_MODULE);
2728
2729 /* driverloader was caught wrongly pretending to be under GPL */
2730 if (strcmp(mod->name, "driverloader") == 0)
2731 add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
2732
2733#ifdef CONFIG_MODVERSIONS
2734 if ((mod->num_syms && !mod->crcs)
2735 || (mod->num_gpl_syms && !mod->gpl_crcs)
2736 || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
2737#ifdef CONFIG_UNUSED_SYMBOLS
2738 || (mod->num_unused_syms && !mod->unused_crcs)
2739 || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
2740#endif
2741 ) {
2742 return try_to_force_load(mod,
2743 "no versions for exported symbols");
2744 }
2745#endif
2746 return 0;
2747}
2748
2749static void flush_module_icache(const struct module *mod)
2750{
2751 mm_segment_t old_fs;
2752
2753 /* flush the icache in correct context */
2754 old_fs = get_fs();
2755 set_fs(KERNEL_DS);
2756
2757 /*
2758 * Flush the instruction cache, since we've played with text.
2759 * Do it before processing of module parameters, so the module
2760 * can provide parameter accessor functions of its own.
2761 */
2762 if (mod->module_init)
2763 flush_icache_range((unsigned long)mod->module_init,
2764 (unsigned long)mod->module_init
2765 + mod->init_size);
2766 flush_icache_range((unsigned long)mod->module_core,
2767 (unsigned long)mod->module_core + mod->core_size);
2768
2769 set_fs(old_fs);
2770}
2771
2772int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
2773 Elf_Shdr *sechdrs,
2774 char *secstrings,
2775 struct module *mod)
2776{
2777 return 0;
2778}
2779
2780static struct module *layout_and_allocate(struct load_info *info)
2781{
2782 /* Module within temporary copy. */
2783 struct module *mod;
2784 Elf_Shdr *pcpusec;
2785 int err;
2786
2787 mod = setup_load_info(info);
2788 if (IS_ERR(mod))
2789 return mod;
2790
2791 err = check_modinfo(mod, info);
2792 if (err)
2793 return ERR_PTR(err);
2794
2795 /* Allow arches to frob section contents and sizes. */
2796 err = module_frob_arch_sections(info->hdr, info->sechdrs,
2797 info->secstrings, mod);
2798 if (err < 0)
2799 goto out;
2800
2801 pcpusec = &info->sechdrs[info->index.pcpu];
2802 if (pcpusec->sh_size) {
2803 /* We have a special allocation for this section. */
2804 err = percpu_modalloc(mod,
2805 pcpusec->sh_size, pcpusec->sh_addralign);
2806 if (err)
2807 goto out;
2808 pcpusec->sh_flags &= ~(unsigned long)SHF_ALLOC;
2809 }
2810
2811 /* Determine total sizes, and put offsets in sh_entsize. For now
2812 this is done generically; there doesn't appear to be any
2813 special cases for the architectures. */
2814 layout_sections(mod, info);
2815 layout_symtab(mod, info);
2816
2817 /* Allocate and move to the final place */
2818 err = move_module(mod, info);
2819 if (err)
2820 goto free_percpu;
2821
2822 /* Module has been copied to its final place now: return it. */
2823 mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2824 kmemleak_load_module(mod, info);
2825 return mod;
2826
2827free_percpu:
2828 percpu_modfree(mod);
2829out:
2830 return ERR_PTR(err);
2831}
2832
2833/* mod is no longer valid after this! */
2834static void module_deallocate(struct module *mod, struct load_info *info)
2835{
2836 percpu_modfree(mod);
2837 module_free(mod, mod->module_init);
2838 module_free(mod, mod->module_core);
2839}
2840
2841int __weak module_finalize(const Elf_Ehdr *hdr,
2842 const Elf_Shdr *sechdrs,
2843 struct module *me)
2844{
2845 return 0;
2846}
2847
2848static int post_relocation(struct module *mod, const struct load_info *info)
2849{
2850 /* Sort exception table now relocations are done. */
2851 sort_extable(mod->extable, mod->extable + mod->num_exentries);
2852
2853 /* Copy relocated percpu area over. */
2854 percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
2855 info->sechdrs[info->index.pcpu].sh_size);
2856
2857 /* Setup kallsyms-specific fields. */
2858 add_kallsyms(mod, info);
2859
2860 /* Arch-specific module finalizing. */
2861 return module_finalize(info->hdr, info->sechdrs, mod);
2862}
2863
2864/* Allocate and load the module: note that size of section 0 is always
2865 zero, and we rely on this for optional sections. */
2866static struct module *load_module(void __user *umod,
2867 unsigned long len,
2868 const char __user *uargs)
2869{
2870 struct load_info info = { NULL, };
2871 struct module *mod;
2872 long err;
2873
2874 pr_debug("load_module: umod=%p, len=%lu, uargs=%p\n",
2875 umod, len, uargs);
2876
2877 /* Copy in the blobs from userspace, check they are vaguely sane. */
2878 err = copy_and_check(&info, umod, len, uargs);
2879 if (err)
2880 return ERR_PTR(err);
2881
2882 /* Figure out module layout, and allocate all the memory. */
2883 mod = layout_and_allocate(&info);
2884 if (IS_ERR(mod)) {
2885 err = PTR_ERR(mod);
2886 goto free_copy;
2887 }
2888
2889 /* Now module is in final location, initialize linked lists, etc. */
2890 err = module_unload_init(mod);
2891 if (err)
2892 goto free_module;
2893
2894 /* Now we've got everything in the final locations, we can
2895 * find optional sections. */
2896 find_module_sections(mod, &info);
2897
2898 err = check_module_license_and_versions(mod);
2899 if (err)
2900 goto free_unload;
2901
2902 /* Set up MODINFO_ATTR fields */
2903 setup_modinfo(mod, &info);
2904
2905 /* Fix up syms, so that st_value is a pointer to location. */
2906 err = simplify_symbols(mod, &info);
2907 if (err < 0)
2908 goto free_modinfo;
2909
2910 err = apply_relocations(mod, &info);
2911 if (err < 0)
2912 goto free_modinfo;
2913
2914 err = post_relocation(mod, &info);
2915 if (err < 0)
2916 goto free_modinfo;
2917
2918 flush_module_icache(mod);
2919
2920 /* Now copy in args */
2921 mod->args = strndup_user(uargs, ~0UL >> 1);
2922 if (IS_ERR(mod->args)) {
2923 err = PTR_ERR(mod->args);
2924 goto free_arch_cleanup;
2925 }
2926
2927 /* Mark state as coming so strong_try_module_get() ignores us. */
2928 mod->state = MODULE_STATE_COMING;
2929
2930 /* Now sew it into the lists so we can get lockdep and oops
2931 * info during argument parsing. No one should access us, since
2932 * strong_try_module_get() will fail.
2933 * lockdep/oops can run asynchronous, so use the RCU list insertion
2934 * function to insert in a way safe to concurrent readers.
2935 * The mutex protects against concurrent writers.
2936 */
2937 mutex_lock(&module_mutex);
2938 if (find_module(mod->name)) {
2939 err = -EEXIST;
2940 goto unlock;
2941 }
2942
2943 /* This has to be done once we're sure module name is unique. */
2944 dynamic_debug_setup(info.debug, info.num_debug);
2945
2946 /* Find duplicate symbols */
2947 err = verify_export_symbols(mod);
2948 if (err < 0)
2949 goto ddebug;
2950
2951 module_bug_finalize(info.hdr, info.sechdrs, mod);
2952 list_add_rcu(&mod->list, &modules);
2953 mutex_unlock(&module_mutex);
2954
2955 /* Module is ready to execute: parsing args may do that. */
2956 err = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
2957 -32768, 32767, &ddebug_dyndbg_module_param_cb);
2958 if (err < 0)
2959 goto unlink;
2960
2961 /* Link in to syfs. */
2962 err = mod_sysfs_setup(mod, &info, mod->kp, mod->num_kp);
2963 if (err < 0)
2964 goto unlink;
2965
2966 /* Get rid of temporary copy. */
2967 free_copy(&info);
2968
2969 /* Done! */
2970 trace_module_load(mod);
2971 return mod;
2972
2973 unlink:
2974 mutex_lock(&module_mutex);
2975 /* Unlink carefully: kallsyms could be walking list. */
2976 list_del_rcu(&mod->list);
2977 module_bug_cleanup(mod);
2978
2979 ddebug:
2980 dynamic_debug_remove(info.debug);
2981 unlock:
2982 mutex_unlock(&module_mutex);
2983 synchronize_sched();
2984 kfree(mod->args);
2985 free_arch_cleanup:
2986 module_arch_cleanup(mod);
2987 free_modinfo:
2988 free_modinfo(mod);
2989 free_unload:
2990 module_unload_free(mod);
2991 free_module:
2992 module_deallocate(mod, &info);
2993 free_copy:
2994 free_copy(&info);
2995 return ERR_PTR(err);
2996}
2997
2998/* Call module constructors. */
2999static void do_mod_ctors(struct module *mod)
3000{
3001#ifdef CONFIG_CONSTRUCTORS
3002 unsigned long i;
3003
3004 for (i = 0; i < mod->num_ctors; i++)
3005 mod->ctors[i]();
3006#endif
3007}
3008
3009/* This is where the real work happens */
3010SYSCALL_DEFINE3(init_module, void __user *, umod,
3011 unsigned long, len, const char __user *, uargs)
3012{
3013 struct module *mod;
3014 int ret = 0;
3015
3016 /* Must have permission */
3017 if (!capable(CAP_SYS_MODULE) || modules_disabled)
3018 return -EPERM;
3019
3020 /* Do all the hard work */
3021 mod = load_module(umod, len, uargs);
3022 if (IS_ERR(mod))
3023 return PTR_ERR(mod);
3024
3025 blocking_notifier_call_chain(&module_notify_list,
3026 MODULE_STATE_COMING, mod);
3027
3028 /* Set RO and NX regions for core */
3029 set_section_ro_nx(mod->module_core,
3030 mod->core_text_size,
3031 mod->core_ro_size,
3032 mod->core_size);
3033
3034 /* Set RO and NX regions for init */
3035 set_section_ro_nx(mod->module_init,
3036 mod->init_text_size,
3037 mod->init_ro_size,
3038 mod->init_size);
3039
3040 do_mod_ctors(mod);
3041 /* Start the module */
3042 if (mod->init != NULL)
3043 ret = do_one_initcall(mod->init);
3044 if (ret < 0) {
3045 /* Init routine failed: abort. Try to protect us from
3046 buggy refcounters. */
3047 mod->state = MODULE_STATE_GOING;
3048 synchronize_sched();
3049 module_put(mod);
3050 blocking_notifier_call_chain(&module_notify_list,
3051 MODULE_STATE_GOING, mod);
3052 free_module(mod);
3053 wake_up(&module_wq);
3054 return ret;
3055 }
3056 if (ret > 0) {
3057 printk(KERN_WARNING
3058"%s: '%s'->init suspiciously returned %d, it should follow 0/-E convention\n"
3059"%s: loading module anyway...\n",
3060 __func__, mod->name, ret,
3061 __func__);
3062 dump_stack();
3063 }
3064
3065 /* Now it's a first class citizen! Wake up anyone waiting for it. */
3066 mod->state = MODULE_STATE_LIVE;
3067 wake_up(&module_wq);
3068 blocking_notifier_call_chain(&module_notify_list,
3069 MODULE_STATE_LIVE, mod);
3070
3071 /* We need to finish all async code before the module init sequence is done */
3072 async_synchronize_full();
3073
3074 mutex_lock(&module_mutex);
3075 /* Drop initial reference. */
3076 module_put(mod);
3077 trim_init_extable(mod);
3078#ifdef CONFIG_KALLSYMS
3079 mod->num_symtab = mod->core_num_syms;
3080 mod->symtab = mod->core_symtab;
3081 mod->strtab = mod->core_strtab;
3082#endif
3083 unset_module_init_ro_nx(mod);
3084 module_free(mod, mod->module_init);
3085 mod->module_init = NULL;
3086 mod->init_size = 0;
3087 mod->init_ro_size = 0;
3088 mod->init_text_size = 0;
3089 mutex_unlock(&module_mutex);
3090
3091 return 0;
3092}
3093
3094static inline int within(unsigned long addr, void *start, unsigned long size)
3095{
3096 return ((void *)addr >= start && (void *)addr < start + size);
3097}
3098
3099#ifdef CONFIG_KALLSYMS
3100/*
3101 * This ignores the intensely annoying "mapping symbols" found
3102 * in ARM ELF files: $a, $t and $d.
3103 */
3104static inline int is_arm_mapping_symbol(const char *str)
3105{
3106 return str[0] == '$' && strchr("atd", str[1])
3107 && (str[2] == '\0' || str[2] == '.');
3108}
3109
3110static const char *get_ksymbol(struct module *mod,
3111 unsigned long addr,
3112 unsigned long *size,
3113 unsigned long *offset)
3114{
3115 unsigned int i, best = 0;
3116 unsigned long nextval;
3117
3118 /* At worse, next value is at end of module */
3119 if (within_module_init(addr, mod))
3120 nextval = (unsigned long)mod->module_init+mod->init_text_size;
3121 else
3122 nextval = (unsigned long)mod->module_core+mod->core_text_size;
3123
3124 /* Scan for closest preceding symbol, and next symbol. (ELF
3125 starts real symbols at 1). */
3126 for (i = 1; i < mod->num_symtab; i++) {
3127 if (mod->symtab[i].st_shndx == SHN_UNDEF)
3128 continue;
3129
3130 /* We ignore unnamed symbols: they're uninformative
3131 * and inserted at a whim. */
3132 if (mod->symtab[i].st_value <= addr
3133 && mod->symtab[i].st_value > mod->symtab[best].st_value
3134 && *(mod->strtab + mod->symtab[i].st_name) != '\0'
3135 && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
3136 best = i;
3137 if (mod->symtab[i].st_value > addr
3138 && mod->symtab[i].st_value < nextval
3139 && *(mod->strtab + mod->symtab[i].st_name) != '\0'
3140 && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
3141 nextval = mod->symtab[i].st_value;
3142 }
3143
3144 if (!best)
3145 return NULL;
3146
3147 if (size)
3148 *size = nextval - mod->symtab[best].st_value;
3149 if (offset)
3150 *offset = addr - mod->symtab[best].st_value;
3151 return mod->strtab + mod->symtab[best].st_name;
3152}
3153
3154/* For kallsyms to ask for address resolution. NULL means not found. Careful
3155 * not to lock to avoid deadlock on oopses, simply disable preemption. */
3156const char *module_address_lookup(unsigned long addr,
3157 unsigned long *size,
3158 unsigned long *offset,
3159 char **modname,
3160 char *namebuf)
3161{
3162 struct module *mod;
3163 const char *ret = NULL;
3164
3165 preempt_disable();
3166 list_for_each_entry_rcu(mod, &modules, list) {
3167 if (within_module_init(addr, mod) ||
3168 within_module_core(addr, mod)) {
3169 if (modname)
3170 *modname = mod->name;
3171 ret = get_ksymbol(mod, addr, size, offset);
3172 break;
3173 }
3174 }
3175 /* Make a copy in here where it's safe */
3176 if (ret) {
3177 strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
3178 ret = namebuf;
3179 }
3180 preempt_enable();
3181 return ret;
3182}
3183
3184int lookup_module_symbol_name(unsigned long addr, char *symname)
3185{
3186 struct module *mod;
3187
3188 preempt_disable();
3189 list_for_each_entry_rcu(mod, &modules, list) {
3190 if (within_module_init(addr, mod) ||
3191 within_module_core(addr, mod)) {
3192 const char *sym;
3193
3194 sym = get_ksymbol(mod, addr, NULL, NULL);
3195 if (!sym)
3196 goto out;
3197 strlcpy(symname, sym, KSYM_NAME_LEN);
3198 preempt_enable();
3199 return 0;
3200 }
3201 }
3202out:
3203 preempt_enable();
3204 return -ERANGE;
3205}
3206
3207int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
3208 unsigned long *offset, char *modname, char *name)
3209{
3210 struct module *mod;
3211
3212 preempt_disable();
3213 list_for_each_entry_rcu(mod, &modules, list) {
3214 if (within_module_init(addr, mod) ||
3215 within_module_core(addr, mod)) {
3216 const char *sym;
3217
3218 sym = get_ksymbol(mod, addr, size, offset);
3219 if (!sym)
3220 goto out;
3221 if (modname)
3222 strlcpy(modname, mod->name, MODULE_NAME_LEN);
3223 if (name)
3224 strlcpy(name, sym, KSYM_NAME_LEN);
3225 preempt_enable();
3226 return 0;
3227 }
3228 }
3229out:
3230 preempt_enable();
3231 return -ERANGE;
3232}
3233
3234int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
3235 char *name, char *module_name, int *exported)
3236{
3237 struct module *mod;
3238
3239 preempt_disable();
3240 list_for_each_entry_rcu(mod, &modules, list) {
3241 if (symnum < mod->num_symtab) {
3242 *value = mod->symtab[symnum].st_value;
3243 *type = mod->symtab[symnum].st_info;
3244 strlcpy(name, mod->strtab + mod->symtab[symnum].st_name,
3245 KSYM_NAME_LEN);
3246 strlcpy(module_name, mod->name, MODULE_NAME_LEN);
3247 *exported = is_exported(name, *value, mod);
3248 preempt_enable();
3249 return 0;
3250 }
3251 symnum -= mod->num_symtab;
3252 }
3253 preempt_enable();
3254 return -ERANGE;
3255}
3256
3257static unsigned long mod_find_symname(struct module *mod, const char *name)
3258{
3259 unsigned int i;
3260
3261 for (i = 0; i < mod->num_symtab; i++)
3262 if (strcmp(name, mod->strtab+mod->symtab[i].st_name) == 0 &&
3263 mod->symtab[i].st_info != 'U')
3264 return mod->symtab[i].st_value;
3265 return 0;
3266}
3267
3268/* Look for this name: can be of form module:name. */
3269unsigned long module_kallsyms_lookup_name(const char *name)
3270{
3271 struct module *mod;
3272 char *colon;
3273 unsigned long ret = 0;
3274
3275 /* Don't lock: we're in enough trouble already. */
3276 preempt_disable();
3277 if ((colon = strchr(name, ':')) != NULL) {
3278 *colon = '\0';
3279 if ((mod = find_module(name)) != NULL)
3280 ret = mod_find_symname(mod, colon+1);
3281 *colon = ':';
3282 } else {
3283 list_for_each_entry_rcu(mod, &modules, list)
3284 if ((ret = mod_find_symname(mod, name)) != 0)
3285 break;
3286 }
3287 preempt_enable();
3288 return ret;
3289}
3290
3291int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
3292 struct module *, unsigned long),
3293 void *data)
3294{
3295 struct module *mod;
3296 unsigned int i;
3297 int ret;
3298
3299 list_for_each_entry(mod, &modules, list) {
3300 for (i = 0; i < mod->num_symtab; i++) {
3301 ret = fn(data, mod->strtab + mod->symtab[i].st_name,
3302 mod, mod->symtab[i].st_value);
3303 if (ret != 0)
3304 return ret;
3305 }
3306 }
3307 return 0;
3308}
3309#endif /* CONFIG_KALLSYMS */
3310
3311static char *module_flags(struct module *mod, char *buf)
3312{
3313 int bx = 0;
3314
3315 if (mod->taints ||
3316 mod->state == MODULE_STATE_GOING ||
3317 mod->state == MODULE_STATE_COMING) {
3318 buf[bx++] = '(';
3319 bx += module_flags_taint(mod, buf + bx);
3320 /* Show a - for module-is-being-unloaded */
3321 if (mod->state == MODULE_STATE_GOING)
3322 buf[bx++] = '-';
3323 /* Show a + for module-is-being-loaded */
3324 if (mod->state == MODULE_STATE_COMING)
3325 buf[bx++] = '+';
3326 buf[bx++] = ')';
3327 }
3328 buf[bx] = '\0';
3329
3330 return buf;
3331}
3332
3333#ifdef CONFIG_PROC_FS
3334/* Called by the /proc file system to return a list of modules. */
3335static void *m_start(struct seq_file *m, loff_t *pos)
3336{
3337 mutex_lock(&module_mutex);
3338 return seq_list_start(&modules, *pos);
3339}
3340
3341static void *m_next(struct seq_file *m, void *p, loff_t *pos)
3342{
3343 return seq_list_next(p, &modules, pos);
3344}
3345
3346static void m_stop(struct seq_file *m, void *p)
3347{
3348 mutex_unlock(&module_mutex);
3349}
3350
3351static int m_show(struct seq_file *m, void *p)
3352{
3353 struct module *mod = list_entry(p, struct module, list);
3354 char buf[8];
3355
3356 seq_printf(m, "%s %u",
3357 mod->name, mod->init_size + mod->core_size);
3358 print_unload_info(m, mod);
3359
3360 /* Informative for users. */
3361 seq_printf(m, " %s",
3362 mod->state == MODULE_STATE_GOING ? "Unloading":
3363 mod->state == MODULE_STATE_COMING ? "Loading":
3364 "Live");
3365 /* Used by oprofile and other similar tools. */
3366 seq_printf(m, " 0x%pK", mod->module_core);
3367
3368 /* Taints info */
3369 if (mod->taints)
3370 seq_printf(m, " %s", module_flags(mod, buf));
3371
3372 seq_printf(m, "\n");
3373 return 0;
3374}
3375
3376/* Format: modulename size refcount deps address
3377
3378 Where refcount is a number or -, and deps is a comma-separated list
3379 of depends or -.
3380*/
3381static const struct seq_operations modules_op = {
3382 .start = m_start,
3383 .next = m_next,
3384 .stop = m_stop,
3385 .show = m_show
3386};
3387
3388static int modules_open(struct inode *inode, struct file *file)
3389{
3390 return seq_open(file, &modules_op);
3391}
3392
3393static const struct file_operations proc_modules_operations = {
3394 .open = modules_open,
3395 .read = seq_read,
3396 .llseek = seq_lseek,
3397 .release = seq_release,
3398};
3399
3400static int __init proc_modules_init(void)
3401{
3402 proc_create("modules", 0, NULL, &proc_modules_operations);
3403 return 0;
3404}
3405module_init(proc_modules_init);
3406#endif
3407
3408/* Given an address, look for it in the module exception tables. */
3409const struct exception_table_entry *search_module_extables(unsigned long addr)
3410{
3411 const struct exception_table_entry *e = NULL;
3412 struct module *mod;
3413
3414 preempt_disable();
3415 list_for_each_entry_rcu(mod, &modules, list) {
3416 if (mod->num_exentries == 0)
3417 continue;
3418
3419 e = search_extable(mod->extable,
3420 mod->extable + mod->num_exentries - 1,
3421 addr);
3422 if (e)
3423 break;
3424 }
3425 preempt_enable();
3426
3427 /* Now, if we found one, we are running inside it now, hence
3428 we cannot unload the module, hence no refcnt needed. */
3429 return e;
3430}
3431
3432/*
3433 * is_module_address - is this address inside a module?
3434 * @addr: the address to check.
3435 *
3436 * See is_module_text_address() if you simply want to see if the address
3437 * is code (not data).
3438 */
3439bool is_module_address(unsigned long addr)
3440{
3441 bool ret;
3442
3443 preempt_disable();
3444 ret = __module_address(addr) != NULL;
3445 preempt_enable();
3446
3447 return ret;
3448}
3449
3450/*
3451 * __module_address - get the module which contains an address.
3452 * @addr: the address.
3453 *
3454 * Must be called with preempt disabled or module mutex held so that
3455 * module doesn't get freed during this.
3456 */
3457struct module *__module_address(unsigned long addr)
3458{
3459 struct module *mod;
3460
3461 if (addr < module_addr_min || addr > module_addr_max)
3462 return NULL;
3463
3464 list_for_each_entry_rcu(mod, &modules, list)
3465 if (within_module_core(addr, mod)
3466 || within_module_init(addr, mod))
3467 return mod;
3468 return NULL;
3469}
3470EXPORT_SYMBOL_GPL(__module_address);
3471
3472/*
3473 * is_module_text_address - is this address inside module code?
3474 * @addr: the address to check.
3475 *
3476 * See is_module_address() if you simply want to see if the address is
3477 * anywhere in a module. See kernel_text_address() for testing if an
3478 * address corresponds to kernel or module code.
3479 */
3480bool is_module_text_address(unsigned long addr)
3481{
3482 bool ret;
3483
3484 preempt_disable();
3485 ret = __module_text_address(addr) != NULL;
3486 preempt_enable();
3487
3488 return ret;
3489}
3490
3491/*
3492 * __module_text_address - get the module whose code contains an address.
3493 * @addr: the address.
3494 *
3495 * Must be called with preempt disabled or module mutex held so that
3496 * module doesn't get freed during this.
3497 */
3498struct module *__module_text_address(unsigned long addr)
3499{
3500 struct module *mod = __module_address(addr);
3501 if (mod) {
3502 /* Make sure it's within the text section. */
3503 if (!within(addr, mod->module_init, mod->init_text_size)
3504 && !within(addr, mod->module_core, mod->core_text_size))
3505 mod = NULL;
3506 }
3507 return mod;
3508}
3509EXPORT_SYMBOL_GPL(__module_text_address);
3510
3511/* Don't grab lock, we're oopsing. */
3512void print_modules(void)
3513{
3514 struct module *mod;
3515 char buf[8];
3516
3517 printk(KERN_DEFAULT "Modules linked in:");
3518 /* Most callers should already have preempt disabled, but make sure */
3519 preempt_disable();
3520 list_for_each_entry_rcu(mod, &modules, list)
3521 printk(" %s%s", mod->name, module_flags(mod, buf));
3522 preempt_enable();
3523 if (last_unloaded_module[0])
3524 printk(" [last unloaded: %s]", last_unloaded_module);
3525 printk("\n");
3526}
3527
3528#ifdef CONFIG_MODVERSIONS
3529/* Generate the signature for all relevant module structures here.
3530 * If these change, we don't want to try to parse the module. */
3531void module_layout(struct module *mod,
3532 struct modversion_info *ver,
3533 struct kernel_param *kp,
3534 struct kernel_symbol *ks,
3535 struct tracepoint * const *tp)
3536{
3537}
3538EXPORT_SYMBOL(module_layout);
3539#endif