projects/linux·blob v5.3-rc6 · refs

4464 lines · 113.3 KiB

1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 Copyright (C) 2002 Richard Henderson
4 Copyright (C) 2001 Rusty Russell, 2002, 2010 Rusty Russell IBM.
5
6*/
7#include <linux/export.h>
8#include <linux/extable.h>
9#include <linux/moduleloader.h>
10#include <linux/trace_events.h>
11#include <linux/init.h>
12#include <linux/kallsyms.h>
13#include <linux/file.h>
14#include <linux/fs.h>
15#include <linux/sysfs.h>
16#include <linux/kernel.h>
17#include <linux/slab.h>
18#include <linux/vmalloc.h>
19#include <linux/elf.h>
20#include <linux/proc_fs.h>
21#include <linux/security.h>
22#include <linux/seq_file.h>
23#include <linux/syscalls.h>
24#include <linux/fcntl.h>
25#include <linux/rcupdate.h>
26#include <linux/capability.h>
27#include <linux/cpu.h>
28#include <linux/moduleparam.h>
29#include <linux/errno.h>
30#include <linux/err.h>
31#include <linux/vermagic.h>
32#include <linux/notifier.h>
33#include <linux/sched.h>
34#include <linux/device.h>
35#include <linux/string.h>
36#include <linux/mutex.h>
37#include <linux/rculist.h>
38#include <linux/uaccess.h>
39#include <asm/cacheflush.h>
40#include <linux/set_memory.h>
41#include <asm/mmu_context.h>
42#include <linux/license.h>
43#include <asm/sections.h>
44#include <linux/tracepoint.h>
45#include <linux/ftrace.h>
46#include <linux/livepatch.h>
47#include <linux/async.h>
48#include <linux/percpu.h>
49#include <linux/kmemleak.h>
50#include <linux/jump_label.h>
51#include <linux/pfn.h>
52#include <linux/bsearch.h>
53#include <linux/dynamic_debug.h>
54#include <linux/audit.h>
55#include <uapi/linux/module.h>
56#include "module-internal.h"
57
58#define CREATE_TRACE_POINTS
59#include <trace/events/module.h>
60
61#ifndef ARCH_SHF_SMALL
62#define ARCH_SHF_SMALL 0
63#endif
64
65/*
66 * Modules' sections will be aligned on page boundaries
67 * to ensure complete separation of code and data, but
68 * only when CONFIG_ARCH_HAS_STRICT_MODULE_RWX=y
69 */
70#ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX
71# define debug_align(X) ALIGN(X, PAGE_SIZE)
72#else
73# define debug_align(X) (X)
74#endif
75
76/* If this is set, the section belongs in the init part of the module */
77#define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
78
79/*
80 * Mutex protects:
81 * 1) List of modules (also safely readable with preempt_disable),
82 * 2) module_use links,
83 * 3) module_addr_min/module_addr_max.
84 * (delete and add uses RCU list operations). */
85DEFINE_MUTEX(module_mutex);
86EXPORT_SYMBOL_GPL(module_mutex);
87static LIST_HEAD(modules);
88
89/* Work queue for freeing init sections in success case */
90static struct work_struct init_free_wq;
91static struct llist_head init_free_list;
92
93#ifdef CONFIG_MODULES_TREE_LOOKUP
94
95/*
96 * Use a latched RB-tree for __module_address(); this allows us to use
97 * RCU-sched lookups of the address from any context.
98 *
99 * This is conditional on PERF_EVENTS || TRACING because those can really hit
100 * __module_address() hard by doing a lot of stack unwinding; potentially from
101 * NMI context.
102 */
103
104static __always_inline unsigned long __mod_tree_val(struct latch_tree_node *n)
105{
106 struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
107
108 return (unsigned long)layout->base;
109}
110
111static __always_inline unsigned long __mod_tree_size(struct latch_tree_node *n)
112{
113 struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
114
115 return (unsigned long)layout->size;
116}
117
118static __always_inline bool
119mod_tree_less(struct latch_tree_node *a, struct latch_tree_node *b)
120{
121 return __mod_tree_val(a) < __mod_tree_val(b);
122}
123
124static __always_inline int
125mod_tree_comp(void *key, struct latch_tree_node *n)
126{
127 unsigned long val = (unsigned long)key;
128 unsigned long start, end;
129
130 start = __mod_tree_val(n);
131 if (val < start)
132 return -1;
133
134 end = start + __mod_tree_size(n);
135 if (val >= end)
136 return 1;
137
138 return 0;
139}
140
141static const struct latch_tree_ops mod_tree_ops = {
142 .less = mod_tree_less,
143 .comp = mod_tree_comp,
144};
145
146static struct mod_tree_root {
147 struct latch_tree_root root;
148 unsigned long addr_min;
149 unsigned long addr_max;
150} mod_tree __cacheline_aligned = {
151 .addr_min = -1UL,
152};
153
154#define module_addr_min mod_tree.addr_min
155#define module_addr_max mod_tree.addr_max
156
157static noinline void __mod_tree_insert(struct mod_tree_node *node)
158{
159 latch_tree_insert(&node->node, &mod_tree.root, &mod_tree_ops);
160}
161
162static void __mod_tree_remove(struct mod_tree_node *node)
163{
164 latch_tree_erase(&node->node, &mod_tree.root, &mod_tree_ops);
165}
166
167/*
168 * These modifications: insert, remove_init and remove; are serialized by the
169 * module_mutex.
170 */
171static void mod_tree_insert(struct module *mod)
172{
173 mod->core_layout.mtn.mod = mod;
174 mod->init_layout.mtn.mod = mod;
175
176 __mod_tree_insert(&mod->core_layout.mtn);
177 if (mod->init_layout.size)
178 __mod_tree_insert(&mod->init_layout.mtn);
179}
180
181static void mod_tree_remove_init(struct module *mod)
182{
183 if (mod->init_layout.size)
184 __mod_tree_remove(&mod->init_layout.mtn);
185}
186
187static void mod_tree_remove(struct module *mod)
188{
189 __mod_tree_remove(&mod->core_layout.mtn);
190 mod_tree_remove_init(mod);
191}
192
193static struct module *mod_find(unsigned long addr)
194{
195 struct latch_tree_node *ltn;
196
197 ltn = latch_tree_find((void *)addr, &mod_tree.root, &mod_tree_ops);
198 if (!ltn)
199 return NULL;
200
201 return container_of(ltn, struct mod_tree_node, node)->mod;
202}
203
204#else /* MODULES_TREE_LOOKUP */
205
206static unsigned long module_addr_min = -1UL, module_addr_max = 0;
207
208static void mod_tree_insert(struct module *mod) { }
209static void mod_tree_remove_init(struct module *mod) { }
210static void mod_tree_remove(struct module *mod) { }
211
212static struct module *mod_find(unsigned long addr)
213{
214 struct module *mod;
215
216 list_for_each_entry_rcu(mod, &modules, list) {
217 if (within_module(addr, mod))
218 return mod;
219 }
220
221 return NULL;
222}
223
224#endif /* MODULES_TREE_LOOKUP */
225
226/*
227 * Bounds of module text, for speeding up __module_address.
228 * Protected by module_mutex.
229 */
230static void __mod_update_bounds(void *base, unsigned int size)
231{
232 unsigned long min = (unsigned long)base;
233 unsigned long max = min + size;
234
235 if (min < module_addr_min)
236 module_addr_min = min;
237 if (max > module_addr_max)
238 module_addr_max = max;
239}
240
241static void mod_update_bounds(struct module *mod)
242{
243 __mod_update_bounds(mod->core_layout.base, mod->core_layout.size);
244 if (mod->init_layout.size)
245 __mod_update_bounds(mod->init_layout.base, mod->init_layout.size);
246}
247
248#ifdef CONFIG_KGDB_KDB
249struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
250#endif /* CONFIG_KGDB_KDB */
251
252static void module_assert_mutex(void)
253{
254 lockdep_assert_held(&module_mutex);
255}
256
257static void module_assert_mutex_or_preempt(void)
258{
259#ifdef CONFIG_LOCKDEP
260 if (unlikely(!debug_locks))
261 return;
262
263 WARN_ON_ONCE(!rcu_read_lock_sched_held() &&
264 !lockdep_is_held(&module_mutex));
265#endif
266}
267
268static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE);
269module_param(sig_enforce, bool_enable_only, 0644);
270
271/*
272 * Export sig_enforce kernel cmdline parameter to allow other subsystems rely
273 * on that instead of directly to CONFIG_MODULE_SIG_FORCE config.
274 */
275bool is_module_sig_enforced(void)
276{
277 return sig_enforce;
278}
279EXPORT_SYMBOL(is_module_sig_enforced);
280
281void set_module_sig_enforced(void)
282{
283 sig_enforce = true;
284}
285
286/* Block module loading/unloading? */
287int modules_disabled = 0;
288core_param(nomodule, modules_disabled, bint, 0);
289
290/* Waiting for a module to finish initializing? */
291static DECLARE_WAIT_QUEUE_HEAD(module_wq);
292
293static BLOCKING_NOTIFIER_HEAD(module_notify_list);
294
295int register_module_notifier(struct notifier_block *nb)
296{
297 return blocking_notifier_chain_register(&module_notify_list, nb);
298}
299EXPORT_SYMBOL(register_module_notifier);
300
301int unregister_module_notifier(struct notifier_block *nb)
302{
303 return blocking_notifier_chain_unregister(&module_notify_list, nb);
304}
305EXPORT_SYMBOL(unregister_module_notifier);
306
307/*
308 * We require a truly strong try_module_get(): 0 means success.
309 * Otherwise an error is returned due to ongoing or failed
310 * initialization etc.
311 */
312static inline int strong_try_module_get(struct module *mod)
313{
314 BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED);
315 if (mod && mod->state == MODULE_STATE_COMING)
316 return -EBUSY;
317 if (try_module_get(mod))
318 return 0;
319 else
320 return -ENOENT;
321}
322
323static inline void add_taint_module(struct module *mod, unsigned flag,
324 enum lockdep_ok lockdep_ok)
325{
326 add_taint(flag, lockdep_ok);
327 set_bit(flag, &mod->taints);
328}
329
330/*
331 * A thread that wants to hold a reference to a module only while it
332 * is running can call this to safely exit. nfsd and lockd use this.
333 */
334void __noreturn __module_put_and_exit(struct module *mod, long code)
335{
336 module_put(mod);
337 do_exit(code);
338}
339EXPORT_SYMBOL(__module_put_and_exit);
340
341/* Find a module section: 0 means not found. */
342static unsigned int find_sec(const struct load_info *info, const char *name)
343{
344 unsigned int i;
345
346 for (i = 1; i < info->hdr->e_shnum; i++) {
347 Elf_Shdr *shdr = &info->sechdrs[i];
348 /* Alloc bit cleared means "ignore it." */
349 if ((shdr->sh_flags & SHF_ALLOC)
350 && strcmp(info->secstrings + shdr->sh_name, name) == 0)
351 return i;
352 }
353 return 0;
354}
355
356/* Find a module section, or NULL. */
357static void *section_addr(const struct load_info *info, const char *name)
358{
359 /* Section 0 has sh_addr 0. */
360 return (void *)info->sechdrs[find_sec(info, name)].sh_addr;
361}
362
363/* Find a module section, or NULL. Fill in number of "objects" in section. */
364static void *section_objs(const struct load_info *info,
365 const char *name,
366 size_t object_size,
367 unsigned int *num)
368{
369 unsigned int sec = find_sec(info, name);
370
371 /* Section 0 has sh_addr 0 and sh_size 0. */
372 *num = info->sechdrs[sec].sh_size / object_size;
373 return (void *)info->sechdrs[sec].sh_addr;
374}
375
376/* Provided by the linker */
377extern const struct kernel_symbol __start___ksymtab[];
378extern const struct kernel_symbol __stop___ksymtab[];
379extern const struct kernel_symbol __start___ksymtab_gpl[];
380extern const struct kernel_symbol __stop___ksymtab_gpl[];
381extern const struct kernel_symbol __start___ksymtab_gpl_future[];
382extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
383extern const s32 __start___kcrctab[];
384extern const s32 __start___kcrctab_gpl[];
385extern const s32 __start___kcrctab_gpl_future[];
386#ifdef CONFIG_UNUSED_SYMBOLS
387extern const struct kernel_symbol __start___ksymtab_unused[];
388extern const struct kernel_symbol __stop___ksymtab_unused[];
389extern const struct kernel_symbol __start___ksymtab_unused_gpl[];
390extern const struct kernel_symbol __stop___ksymtab_unused_gpl[];
391extern const s32 __start___kcrctab_unused[];
392extern const s32 __start___kcrctab_unused_gpl[];
393#endif
394
395#ifndef CONFIG_MODVERSIONS
396#define symversion(base, idx) NULL
397#else
398#define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
399#endif
400
401static bool each_symbol_in_section(const struct symsearch *arr,
402 unsigned int arrsize,
403 struct module *owner,
404 bool (*fn)(const struct symsearch *syms,
405 struct module *owner,
406 void *data),
407 void *data)
408{
409 unsigned int j;
410
411 for (j = 0; j < arrsize; j++) {
412 if (fn(&arr[j], owner, data))
413 return true;
414 }
415
416 return false;
417}
418
419/* Returns true as soon as fn returns true, otherwise false. */
420bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
421 struct module *owner,
422 void *data),
423 void *data)
424{
425 struct module *mod;
426 static const struct symsearch arr[] = {
427 { __start___ksymtab, __stop___ksymtab, __start___kcrctab,
428 NOT_GPL_ONLY, false },
429 { __start___ksymtab_gpl, __stop___ksymtab_gpl,
430 __start___kcrctab_gpl,
431 GPL_ONLY, false },
432 { __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future,
433 __start___kcrctab_gpl_future,
434 WILL_BE_GPL_ONLY, false },
435#ifdef CONFIG_UNUSED_SYMBOLS
436 { __start___ksymtab_unused, __stop___ksymtab_unused,
437 __start___kcrctab_unused,
438 NOT_GPL_ONLY, true },
439 { __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl,
440 __start___kcrctab_unused_gpl,
441 GPL_ONLY, true },
442#endif
443 };
444
445 module_assert_mutex_or_preempt();
446
447 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data))
448 return true;
449
450 list_for_each_entry_rcu(mod, &modules, list) {
451 struct symsearch arr[] = {
452 { mod->syms, mod->syms + mod->num_syms, mod->crcs,
453 NOT_GPL_ONLY, false },
454 { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
455 mod->gpl_crcs,
456 GPL_ONLY, false },
457 { mod->gpl_future_syms,
458 mod->gpl_future_syms + mod->num_gpl_future_syms,
459 mod->gpl_future_crcs,
460 WILL_BE_GPL_ONLY, false },
461#ifdef CONFIG_UNUSED_SYMBOLS
462 { mod->unused_syms,
463 mod->unused_syms + mod->num_unused_syms,
464 mod->unused_crcs,
465 NOT_GPL_ONLY, true },
466 { mod->unused_gpl_syms,
467 mod->unused_gpl_syms + mod->num_unused_gpl_syms,
468 mod->unused_gpl_crcs,
469 GPL_ONLY, true },
470#endif
471 };
472
473 if (mod->state == MODULE_STATE_UNFORMED)
474 continue;
475
476 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data))
477 return true;
478 }
479 return false;
480}
481EXPORT_SYMBOL_GPL(each_symbol_section);
482
483struct find_symbol_arg {
484 /* Input */
485 const char *name;
486 bool gplok;
487 bool warn;
488
489 /* Output */
490 struct module *owner;
491 const s32 *crc;
492 const struct kernel_symbol *sym;
493};
494
495static bool check_exported_symbol(const struct symsearch *syms,
496 struct module *owner,
497 unsigned int symnum, void *data)
498{
499 struct find_symbol_arg *fsa = data;
500
501 if (!fsa->gplok) {
502 if (syms->licence == GPL_ONLY)
503 return false;
504 if (syms->licence == WILL_BE_GPL_ONLY && fsa->warn) {
505 pr_warn("Symbol %s is being used by a non-GPL module, "
506 "which will not be allowed in the future\n",
507 fsa->name);
508 }
509 }
510
511#ifdef CONFIG_UNUSED_SYMBOLS
512 if (syms->unused && fsa->warn) {
513 pr_warn("Symbol %s is marked as UNUSED, however this module is "
514 "using it.\n", fsa->name);
515 pr_warn("This symbol will go away in the future.\n");
516 pr_warn("Please evaluate if this is the right api to use and "
517 "if it really is, submit a report to the linux kernel "
518 "mailing list together with submitting your code for "
519 "inclusion.\n");
520 }
521#endif
522
523 fsa->owner = owner;
524 fsa->crc = symversion(syms->crcs, symnum);
525 fsa->sym = &syms->start[symnum];
526 return true;
527}
528
529static unsigned long kernel_symbol_value(const struct kernel_symbol *sym)
530{
531#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
532 return (unsigned long)offset_to_ptr(&sym->value_offset);
533#else
534 return sym->value;
535#endif
536}
537
538static const char *kernel_symbol_name(const struct kernel_symbol *sym)
539{
540#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
541 return offset_to_ptr(&sym->name_offset);
542#else
543 return sym->name;
544#endif
545}
546
547static int cmp_name(const void *va, const void *vb)
548{
549 const char *a;
550 const struct kernel_symbol *b;
551 a = va; b = vb;
552 return strcmp(a, kernel_symbol_name(b));
553}
554
555static bool find_exported_symbol_in_section(const struct symsearch *syms,
556 struct module *owner,
557 void *data)
558{
559 struct find_symbol_arg *fsa = data;
560 struct kernel_symbol *sym;
561
562 sym = bsearch(fsa->name, syms->start, syms->stop - syms->start,
563 sizeof(struct kernel_symbol), cmp_name);
564
565 if (sym != NULL && check_exported_symbol(syms, owner,
566 sym - syms->start, data))
567 return true;
568
569 return false;
570}
571
572/* Find an exported symbol and return it, along with, (optional) crc and
573 * (optional) module which owns it. Needs preempt disabled or module_mutex. */
574const struct kernel_symbol *find_symbol(const char *name,
575 struct module **owner,
576 const s32 **crc,
577 bool gplok,
578 bool warn)
579{
580 struct find_symbol_arg fsa;
581
582 fsa.name = name;
583 fsa.gplok = gplok;
584 fsa.warn = warn;
585
586 if (each_symbol_section(find_exported_symbol_in_section, &fsa)) {
587 if (owner)
588 *owner = fsa.owner;
589 if (crc)
590 *crc = fsa.crc;
591 return fsa.sym;
592 }
593
594 pr_debug("Failed to find symbol %s\n", name);
595 return NULL;
596}
597EXPORT_SYMBOL_GPL(find_symbol);
598
599/*
600 * Search for module by name: must hold module_mutex (or preempt disabled
601 * for read-only access).
602 */
603static struct module *find_module_all(const char *name, size_t len,
604 bool even_unformed)
605{
606 struct module *mod;
607
608 module_assert_mutex_or_preempt();
609
610 list_for_each_entry_rcu(mod, &modules, list) {
611 if (!even_unformed && mod->state == MODULE_STATE_UNFORMED)
612 continue;
613 if (strlen(mod->name) == len && !memcmp(mod->name, name, len))
614 return mod;
615 }
616 return NULL;
617}
618
619struct module *find_module(const char *name)
620{
621 module_assert_mutex();
622 return find_module_all(name, strlen(name), false);
623}
624EXPORT_SYMBOL_GPL(find_module);
625
626#ifdef CONFIG_SMP
627
628static inline void __percpu *mod_percpu(struct module *mod)
629{
630 return mod->percpu;
631}
632
633static int percpu_modalloc(struct module *mod, struct load_info *info)
634{
635 Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu];
636 unsigned long align = pcpusec->sh_addralign;
637
638 if (!pcpusec->sh_size)
639 return 0;
640
641 if (align > PAGE_SIZE) {
642 pr_warn("%s: per-cpu alignment %li > %li\n",
643 mod->name, align, PAGE_SIZE);
644 align = PAGE_SIZE;
645 }
646
647 mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align);
648 if (!mod->percpu) {
649 pr_warn("%s: Could not allocate %lu bytes percpu data\n",
650 mod->name, (unsigned long)pcpusec->sh_size);
651 return -ENOMEM;
652 }
653 mod->percpu_size = pcpusec->sh_size;
654 return 0;
655}
656
657static void percpu_modfree(struct module *mod)
658{
659 free_percpu(mod->percpu);
660}
661
662static unsigned int find_pcpusec(struct load_info *info)
663{
664 return find_sec(info, ".data..percpu");
665}
666
667static void percpu_modcopy(struct module *mod,
668 const void *from, unsigned long size)
669{
670 int cpu;
671
672 for_each_possible_cpu(cpu)
673 memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
674}
675
676bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
677{
678 struct module *mod;
679 unsigned int cpu;
680
681 preempt_disable();
682
683 list_for_each_entry_rcu(mod, &modules, list) {
684 if (mod->state == MODULE_STATE_UNFORMED)
685 continue;
686 if (!mod->percpu_size)
687 continue;
688 for_each_possible_cpu(cpu) {
689 void *start = per_cpu_ptr(mod->percpu, cpu);
690 void *va = (void *)addr;
691
692 if (va >= start && va < start + mod->percpu_size) {
693 if (can_addr) {
694 *can_addr = (unsigned long) (va - start);
695 *can_addr += (unsigned long)
696 per_cpu_ptr(mod->percpu,
697 get_boot_cpu_id());
698 }
699 preempt_enable();
700 return true;
701 }
702 }
703 }
704
705 preempt_enable();
706 return false;
707}
708
709/**
710 * is_module_percpu_address - test whether address is from module static percpu
711 * @addr: address to test
712 *
713 * Test whether @addr belongs to module static percpu area.
714 *
715 * RETURNS:
716 * %true if @addr is from module static percpu area
717 */
718bool is_module_percpu_address(unsigned long addr)
719{
720 return __is_module_percpu_address(addr, NULL);
721}
722
723#else /* ... !CONFIG_SMP */
724
725static inline void __percpu *mod_percpu(struct module *mod)
726{
727 return NULL;
728}
729static int percpu_modalloc(struct module *mod, struct load_info *info)
730{
731 /* UP modules shouldn't have this section: ENOMEM isn't quite right */
732 if (info->sechdrs[info->index.pcpu].sh_size != 0)
733 return -ENOMEM;
734 return 0;
735}
736static inline void percpu_modfree(struct module *mod)
737{
738}
739static unsigned int find_pcpusec(struct load_info *info)
740{
741 return 0;
742}
743static inline void percpu_modcopy(struct module *mod,
744 const void *from, unsigned long size)
745{
746 /* pcpusec should be 0, and size of that section should be 0. */
747 BUG_ON(size != 0);
748}
749bool is_module_percpu_address(unsigned long addr)
750{
751 return false;
752}
753
754bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
755{
756 return false;
757}
758
759#endif /* CONFIG_SMP */
760
761#define MODINFO_ATTR(field) \
762static void setup_modinfo_##field(struct module *mod, const char *s) \
763{ \
764 mod->field = kstrdup(s, GFP_KERNEL); \
765} \
766static ssize_t show_modinfo_##field(struct module_attribute *mattr, \
767 struct module_kobject *mk, char *buffer) \
768{ \
769 return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field); \
770} \
771static int modinfo_##field##_exists(struct module *mod) \
772{ \
773 return mod->field != NULL; \
774} \
775static void free_modinfo_##field(struct module *mod) \
776{ \
777 kfree(mod->field); \
778 mod->field = NULL; \
779} \
780static struct module_attribute modinfo_##field = { \
781 .attr = { .name = __stringify(field), .mode = 0444 }, \
782 .show = show_modinfo_##field, \
783 .setup = setup_modinfo_##field, \
784 .test = modinfo_##field##_exists, \
785 .free = free_modinfo_##field, \
786};
787
788MODINFO_ATTR(version);
789MODINFO_ATTR(srcversion);
790
791static char last_unloaded_module[MODULE_NAME_LEN+1];
792
793#ifdef CONFIG_MODULE_UNLOAD
794
795EXPORT_TRACEPOINT_SYMBOL(module_get);
796
797/* MODULE_REF_BASE is the base reference count by kmodule loader. */
798#define MODULE_REF_BASE 1
799
800/* Init the unload section of the module. */
801static int module_unload_init(struct module *mod)
802{
803 /*
804 * Initialize reference counter to MODULE_REF_BASE.
805 * refcnt == 0 means module is going.
806 */
807 atomic_set(&mod->refcnt, MODULE_REF_BASE);
808
809 INIT_LIST_HEAD(&mod->source_list);
810 INIT_LIST_HEAD(&mod->target_list);
811
812 /* Hold reference count during initialization. */
813 atomic_inc(&mod->refcnt);
814
815 return 0;
816}
817
818/* Does a already use b? */
819static int already_uses(struct module *a, struct module *b)
820{
821 struct module_use *use;
822
823 list_for_each_entry(use, &b->source_list, source_list) {
824 if (use->source == a) {
825 pr_debug("%s uses %s!\n", a->name, b->name);
826 return 1;
827 }
828 }
829 pr_debug("%s does not use %s!\n", a->name, b->name);
830 return 0;
831}
832
833/*
834 * Module a uses b
835 * - we add 'a' as a "source", 'b' as a "target" of module use
836 * - the module_use is added to the list of 'b' sources (so
837 * 'b' can walk the list to see who sourced them), and of 'a'
838 * targets (so 'a' can see what modules it targets).
839 */
840static int add_module_usage(struct module *a, struct module *b)
841{
842 struct module_use *use;
843
844 pr_debug("Allocating new usage for %s.\n", a->name);
845 use = kmalloc(sizeof(*use), GFP_ATOMIC);
846 if (!use)
847 return -ENOMEM;
848
849 use->source = a;
850 use->target = b;
851 list_add(&use->source_list, &b->source_list);
852 list_add(&use->target_list, &a->target_list);
853 return 0;
854}
855
856/* Module a uses b: caller needs module_mutex() */
857int ref_module(struct module *a, struct module *b)
858{
859 int err;
860
861 if (b == NULL || already_uses(a, b))
862 return 0;
863
864 /* If module isn't available, we fail. */
865 err = strong_try_module_get(b);
866 if (err)
867 return err;
868
869 err = add_module_usage(a, b);
870 if (err) {
871 module_put(b);
872 return err;
873 }
874 return 0;
875}
876EXPORT_SYMBOL_GPL(ref_module);
877
878/* Clear the unload stuff of the module. */
879static void module_unload_free(struct module *mod)
880{
881 struct module_use *use, *tmp;
882
883 mutex_lock(&module_mutex);
884 list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
885 struct module *i = use->target;
886 pr_debug("%s unusing %s\n", mod->name, i->name);
887 module_put(i);
888 list_del(&use->source_list);
889 list_del(&use->target_list);
890 kfree(use);
891 }
892 mutex_unlock(&module_mutex);
893}
894
895#ifdef CONFIG_MODULE_FORCE_UNLOAD
896static inline int try_force_unload(unsigned int flags)
897{
898 int ret = (flags & O_TRUNC);
899 if (ret)
900 add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE);
901 return ret;
902}
903#else
904static inline int try_force_unload(unsigned int flags)
905{
906 return 0;
907}
908#endif /* CONFIG_MODULE_FORCE_UNLOAD */
909
910/* Try to release refcount of module, 0 means success. */
911static int try_release_module_ref(struct module *mod)
912{
913 int ret;
914
915 /* Try to decrement refcnt which we set at loading */
916 ret = atomic_sub_return(MODULE_REF_BASE, &mod->refcnt);
917 BUG_ON(ret < 0);
918 if (ret)
919 /* Someone can put this right now, recover with checking */
920 ret = atomic_add_unless(&mod->refcnt, MODULE_REF_BASE, 0);
921
922 return ret;
923}
924
925static int try_stop_module(struct module *mod, int flags, int *forced)
926{
927 /* If it's not unused, quit unless we're forcing. */
928 if (try_release_module_ref(mod) != 0) {
929 *forced = try_force_unload(flags);
930 if (!(*forced))
931 return -EWOULDBLOCK;
932 }
933
934 /* Mark it as dying. */
935 mod->state = MODULE_STATE_GOING;
936
937 return 0;
938}
939
940/**
941 * module_refcount - return the refcount or -1 if unloading
942 *
943 * @mod: the module we're checking
944 *
945 * Returns:
946 * -1 if the module is in the process of unloading
947 * otherwise the number of references in the kernel to the module
948 */
949int module_refcount(struct module *mod)
950{
951 return atomic_read(&mod->refcnt) - MODULE_REF_BASE;
952}
953EXPORT_SYMBOL(module_refcount);
954
955/* This exists whether we can unload or not */
956static void free_module(struct module *mod);
957
958SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
959 unsigned int, flags)
960{
961 struct module *mod;
962 char name[MODULE_NAME_LEN];
963 int ret, forced = 0;
964
965 if (!capable(CAP_SYS_MODULE) || modules_disabled)
966 return -EPERM;
967
968 if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
969 return -EFAULT;
970 name[MODULE_NAME_LEN-1] = '\0';
971
972 audit_log_kern_module(name);
973
974 if (mutex_lock_interruptible(&module_mutex) != 0)
975 return -EINTR;
976
977 mod = find_module(name);
978 if (!mod) {
979 ret = -ENOENT;
980 goto out;
981 }
982
983 if (!list_empty(&mod->source_list)) {
984 /* Other modules depend on us: get rid of them first. */
985 ret = -EWOULDBLOCK;
986 goto out;
987 }
988
989 /* Doing init or already dying? */
990 if (mod->state != MODULE_STATE_LIVE) {
991 /* FIXME: if (force), slam module count damn the torpedoes */
992 pr_debug("%s already dying\n", mod->name);
993 ret = -EBUSY;
994 goto out;
995 }
996
997 /* If it has an init func, it must have an exit func to unload */
998 if (mod->init && !mod->exit) {
999 forced = try_force_unload(flags);
1000 if (!forced) {
1001 /* This module can't be removed */
1002 ret = -EBUSY;
1003 goto out;
1004 }
1005 }
1006
1007 /* Stop the machine so refcounts can't move and disable module. */
1008 ret = try_stop_module(mod, flags, &forced);
1009 if (ret != 0)
1010 goto out;
1011
1012 mutex_unlock(&module_mutex);
1013 /* Final destruction now no one is using it. */
1014 if (mod->exit != NULL)
1015 mod->exit();
1016 blocking_notifier_call_chain(&module_notify_list,
1017 MODULE_STATE_GOING, mod);
1018 klp_module_going(mod);
1019 ftrace_release_mod(mod);
1020
1021 async_synchronize_full();
1022
1023 /* Store the name of the last unloaded module for diagnostic purposes */
1024 strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
1025
1026 free_module(mod);
1027 return 0;
1028out:
1029 mutex_unlock(&module_mutex);
1030 return ret;
1031}
1032
1033static inline void print_unload_info(struct seq_file *m, struct module *mod)
1034{
1035 struct module_use *use;
1036 int printed_something = 0;
1037
1038 seq_printf(m, " %i ", module_refcount(mod));
1039
1040 /*
1041 * Always include a trailing , so userspace can differentiate
1042 * between this and the old multi-field proc format.
1043 */
1044 list_for_each_entry(use, &mod->source_list, source_list) {
1045 printed_something = 1;
1046 seq_printf(m, "%s,", use->source->name);
1047 }
1048
1049 if (mod->init != NULL && mod->exit == NULL) {
1050 printed_something = 1;
1051 seq_puts(m, "[permanent],");
1052 }
1053
1054 if (!printed_something)
1055 seq_puts(m, "-");
1056}
1057
1058void __symbol_put(const char *symbol)
1059{
1060 struct module *owner;
1061
1062 preempt_disable();
1063 if (!find_symbol(symbol, &owner, NULL, true, false))
1064 BUG();
1065 module_put(owner);
1066 preempt_enable();
1067}
1068EXPORT_SYMBOL(__symbol_put);
1069
1070/* Note this assumes addr is a function, which it currently always is. */
1071void symbol_put_addr(void *addr)
1072{
1073 struct module *modaddr;
1074 unsigned long a = (unsigned long)dereference_function_descriptor(addr);
1075
1076 if (core_kernel_text(a))
1077 return;
1078
1079 /*
1080 * Even though we hold a reference on the module; we still need to
1081 * disable preemption in order to safely traverse the data structure.
1082 */
1083 preempt_disable();
1084 modaddr = __module_text_address(a);
1085 BUG_ON(!modaddr);
1086 module_put(modaddr);
1087 preempt_enable();
1088}
1089EXPORT_SYMBOL_GPL(symbol_put_addr);
1090
1091static ssize_t show_refcnt(struct module_attribute *mattr,
1092 struct module_kobject *mk, char *buffer)
1093{
1094 return sprintf(buffer, "%i\n", module_refcount(mk->mod));
1095}
1096
1097static struct module_attribute modinfo_refcnt =
1098 __ATTR(refcnt, 0444, show_refcnt, NULL);
1099
1100void __module_get(struct module *module)
1101{
1102 if (module) {
1103 preempt_disable();
1104 atomic_inc(&module->refcnt);
1105 trace_module_get(module, _RET_IP_);
1106 preempt_enable();
1107 }
1108}
1109EXPORT_SYMBOL(__module_get);
1110
1111bool try_module_get(struct module *module)
1112{
1113 bool ret = true;
1114
1115 if (module) {
1116 preempt_disable();
1117 /* Note: here, we can fail to get a reference */
1118 if (likely(module_is_live(module) &&
1119 atomic_inc_not_zero(&module->refcnt) != 0))
1120 trace_module_get(module, _RET_IP_);
1121 else
1122 ret = false;
1123
1124 preempt_enable();
1125 }
1126 return ret;
1127}
1128EXPORT_SYMBOL(try_module_get);
1129
1130void module_put(struct module *module)
1131{
1132 int ret;
1133
1134 if (module) {
1135 preempt_disable();
1136 ret = atomic_dec_if_positive(&module->refcnt);
1137 WARN_ON(ret < 0); /* Failed to put refcount */
1138 trace_module_put(module, _RET_IP_);
1139 preempt_enable();
1140 }
1141}
1142EXPORT_SYMBOL(module_put);
1143
1144#else /* !CONFIG_MODULE_UNLOAD */
1145static inline void print_unload_info(struct seq_file *m, struct module *mod)
1146{
1147 /* We don't know the usage count, or what modules are using. */
1148 seq_puts(m, " - -");
1149}
1150
1151static inline void module_unload_free(struct module *mod)
1152{
1153}
1154
1155int ref_module(struct module *a, struct module *b)
1156{
1157 return strong_try_module_get(b);
1158}
1159EXPORT_SYMBOL_GPL(ref_module);
1160
1161static inline int module_unload_init(struct module *mod)
1162{
1163 return 0;
1164}
1165#endif /* CONFIG_MODULE_UNLOAD */
1166
1167static size_t module_flags_taint(struct module *mod, char *buf)
1168{
1169 size_t l = 0;
1170 int i;
1171
1172 for (i = 0; i < TAINT_FLAGS_COUNT; i++) {
1173 if (taint_flags[i].module && test_bit(i, &mod->taints))
1174 buf[l++] = taint_flags[i].c_true;
1175 }
1176
1177 return l;
1178}
1179
1180static ssize_t show_initstate(struct module_attribute *mattr,
1181 struct module_kobject *mk, char *buffer)
1182{
1183 const char *state = "unknown";
1184
1185 switch (mk->mod->state) {
1186 case MODULE_STATE_LIVE:
1187 state = "live";
1188 break;
1189 case MODULE_STATE_COMING:
1190 state = "coming";
1191 break;
1192 case MODULE_STATE_GOING:
1193 state = "going";
1194 break;
1195 default:
1196 BUG();
1197 }
1198 return sprintf(buffer, "%s\n", state);
1199}
1200
1201static struct module_attribute modinfo_initstate =
1202 __ATTR(initstate, 0444, show_initstate, NULL);
1203
1204static ssize_t store_uevent(struct module_attribute *mattr,
1205 struct module_kobject *mk,
1206 const char *buffer, size_t count)
1207{
1208 int rc;
1209
1210 rc = kobject_synth_uevent(&mk->kobj, buffer, count);
1211 return rc ? rc : count;
1212}
1213
1214struct module_attribute module_uevent =
1215 __ATTR(uevent, 0200, NULL, store_uevent);
1216
1217static ssize_t show_coresize(struct module_attribute *mattr,
1218 struct module_kobject *mk, char *buffer)
1219{
1220 return sprintf(buffer, "%u\n", mk->mod->core_layout.size);
1221}
1222
1223static struct module_attribute modinfo_coresize =
1224 __ATTR(coresize, 0444, show_coresize, NULL);
1225
1226static ssize_t show_initsize(struct module_attribute *mattr,
1227 struct module_kobject *mk, char *buffer)
1228{
1229 return sprintf(buffer, "%u\n", mk->mod->init_layout.size);
1230}
1231
1232static struct module_attribute modinfo_initsize =
1233 __ATTR(initsize, 0444, show_initsize, NULL);
1234
1235static ssize_t show_taint(struct module_attribute *mattr,
1236 struct module_kobject *mk, char *buffer)
1237{
1238 size_t l;
1239
1240 l = module_flags_taint(mk->mod, buffer);
1241 buffer[l++] = '\n';
1242 return l;
1243}
1244
1245static struct module_attribute modinfo_taint =
1246 __ATTR(taint, 0444, show_taint, NULL);
1247
1248static struct module_attribute *modinfo_attrs[] = {
1249 &module_uevent,
1250 &modinfo_version,
1251 &modinfo_srcversion,
1252 &modinfo_initstate,
1253 &modinfo_coresize,
1254 &modinfo_initsize,
1255 &modinfo_taint,
1256#ifdef CONFIG_MODULE_UNLOAD
1257 &modinfo_refcnt,
1258#endif
1259 NULL,
1260};
1261
1262static const char vermagic[] = VERMAGIC_STRING;
1263
1264static int try_to_force_load(struct module *mod, const char *reason)
1265{
1266#ifdef CONFIG_MODULE_FORCE_LOAD
1267 if (!test_taint(TAINT_FORCED_MODULE))
1268 pr_warn("%s: %s: kernel tainted.\n", mod->name, reason);
1269 add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
1270 return 0;
1271#else
1272 return -ENOEXEC;
1273#endif
1274}
1275
1276#ifdef CONFIG_MODVERSIONS
1277
1278static u32 resolve_rel_crc(const s32 *crc)
1279{
1280 return *(u32 *)((void *)crc + *crc);
1281}
1282
1283static int check_version(const struct load_info *info,
1284 const char *symname,
1285 struct module *mod,
1286 const s32 *crc)
1287{
1288 Elf_Shdr *sechdrs = info->sechdrs;
1289 unsigned int versindex = info->index.vers;
1290 unsigned int i, num_versions;
1291 struct modversion_info *versions;
1292
1293 /* Exporting module didn't supply crcs? OK, we're already tainted. */
1294 if (!crc)
1295 return 1;
1296
1297 /* No versions at all? modprobe --force does this. */
1298 if (versindex == 0)
1299 return try_to_force_load(mod, symname) == 0;
1300
1301 versions = (void *) sechdrs[versindex].sh_addr;
1302 num_versions = sechdrs[versindex].sh_size
1303 / sizeof(struct modversion_info);
1304
1305 for (i = 0; i < num_versions; i++) {
1306 u32 crcval;
1307
1308 if (strcmp(versions[i].name, symname) != 0)
1309 continue;
1310
1311 if (IS_ENABLED(CONFIG_MODULE_REL_CRCS))
1312 crcval = resolve_rel_crc(crc);
1313 else
1314 crcval = *crc;
1315 if (versions[i].crc == crcval)
1316 return 1;
1317 pr_debug("Found checksum %X vs module %lX\n",
1318 crcval, versions[i].crc);
1319 goto bad_version;
1320 }
1321
1322 /* Broken toolchain. Warn once, then let it go.. */
1323 pr_warn_once("%s: no symbol version for %s\n", info->name, symname);
1324 return 1;
1325
1326bad_version:
1327 pr_warn("%s: disagrees about version of symbol %s\n",
1328 info->name, symname);
1329 return 0;
1330}
1331
1332static inline int check_modstruct_version(const struct load_info *info,
1333 struct module *mod)
1334{
1335 const s32 *crc;
1336
1337 /*
1338 * Since this should be found in kernel (which can't be removed), no
1339 * locking is necessary -- use preempt_disable() to placate lockdep.
1340 */
1341 preempt_disable();
1342 if (!find_symbol("module_layout", NULL, &crc, true, false)) {
1343 preempt_enable();
1344 BUG();
1345 }
1346 preempt_enable();
1347 return check_version(info, "module_layout", mod, crc);
1348}
1349
1350/* First part is kernel version, which we ignore if module has crcs. */
1351static inline int same_magic(const char *amagic, const char *bmagic,
1352 bool has_crcs)
1353{
1354 if (has_crcs) {
1355 amagic += strcspn(amagic, " ");
1356 bmagic += strcspn(bmagic, " ");
1357 }
1358 return strcmp(amagic, bmagic) == 0;
1359}
1360#else
1361static inline int check_version(const struct load_info *info,
1362 const char *symname,
1363 struct module *mod,
1364 const s32 *crc)
1365{
1366 return 1;
1367}
1368
1369static inline int check_modstruct_version(const struct load_info *info,
1370 struct module *mod)
1371{
1372 return 1;
1373}
1374
1375static inline int same_magic(const char *amagic, const char *bmagic,
1376 bool has_crcs)
1377{
1378 return strcmp(amagic, bmagic) == 0;
1379}
1380#endif /* CONFIG_MODVERSIONS */
1381
1382/* Resolve a symbol for this module. I.e. if we find one, record usage. */
1383static const struct kernel_symbol *resolve_symbol(struct module *mod,
1384 const struct load_info *info,
1385 const char *name,
1386 char ownername[])
1387{
1388 struct module *owner;
1389 const struct kernel_symbol *sym;
1390 const s32 *crc;
1391 int err;
1392
1393 /*
1394 * The module_mutex should not be a heavily contended lock;
1395 * if we get the occasional sleep here, we'll go an extra iteration
1396 * in the wait_event_interruptible(), which is harmless.
1397 */
1398 sched_annotate_sleep();
1399 mutex_lock(&module_mutex);
1400 sym = find_symbol(name, &owner, &crc,
1401 !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
1402 if (!sym)
1403 goto unlock;
1404
1405 if (!check_version(info, name, mod, crc)) {
1406 sym = ERR_PTR(-EINVAL);
1407 goto getname;
1408 }
1409
1410 err = ref_module(mod, owner);
1411 if (err) {
1412 sym = ERR_PTR(err);
1413 goto getname;
1414 }
1415
1416getname:
1417 /* We must make copy under the lock if we failed to get ref. */
1418 strncpy(ownername, module_name(owner), MODULE_NAME_LEN);
1419unlock:
1420 mutex_unlock(&module_mutex);
1421 return sym;
1422}
1423
1424static const struct kernel_symbol *
1425resolve_symbol_wait(struct module *mod,
1426 const struct load_info *info,
1427 const char *name)
1428{
1429 const struct kernel_symbol *ksym;
1430 char owner[MODULE_NAME_LEN];
1431
1432 if (wait_event_interruptible_timeout(module_wq,
1433 !IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
1434 || PTR_ERR(ksym) != -EBUSY,
1435 30 * HZ) <= 0) {
1436 pr_warn("%s: gave up waiting for init of module %s.\n",
1437 mod->name, owner);
1438 }
1439 return ksym;
1440}
1441
1442/*
1443 * /sys/module/foo/sections stuff
1444 * J. Corbet <[email protected]>
1445 */
1446#ifdef CONFIG_SYSFS
1447
1448#ifdef CONFIG_KALLSYMS
1449static inline bool sect_empty(const Elf_Shdr *sect)
1450{
1451 return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
1452}
1453
1454struct module_sect_attr {
1455 struct module_attribute mattr;
1456 char *name;
1457 unsigned long address;
1458};
1459
1460struct module_sect_attrs {
1461 struct attribute_group grp;
1462 unsigned int nsections;
1463 struct module_sect_attr attrs[0];
1464};
1465
1466static ssize_t module_sect_show(struct module_attribute *mattr,
1467 struct module_kobject *mk, char *buf)
1468{
1469 struct module_sect_attr *sattr =
1470 container_of(mattr, struct module_sect_attr, mattr);
1471 return sprintf(buf, "0x%px\n", kptr_restrict < 2 ?
1472 (void *)sattr->address : NULL);
1473}
1474
1475static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
1476{
1477 unsigned int section;
1478
1479 for (section = 0; section < sect_attrs->nsections; section++)
1480 kfree(sect_attrs->attrs[section].name);
1481 kfree(sect_attrs);
1482}
1483
1484static void add_sect_attrs(struct module *mod, const struct load_info *info)
1485{
1486 unsigned int nloaded = 0, i, size[2];
1487 struct module_sect_attrs *sect_attrs;
1488 struct module_sect_attr *sattr;
1489 struct attribute **gattr;
1490
1491 /* Count loaded sections and allocate structures */
1492 for (i = 0; i < info->hdr->e_shnum; i++)
1493 if (!sect_empty(&info->sechdrs[i]))
1494 nloaded++;
1495 size[0] = ALIGN(struct_size(sect_attrs, attrs, nloaded),
1496 sizeof(sect_attrs->grp.attrs[0]));
1497 size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]);
1498 sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
1499 if (sect_attrs == NULL)
1500 return;
1501
1502 /* Setup section attributes. */
1503 sect_attrs->grp.name = "sections";
1504 sect_attrs->grp.attrs = (void *)sect_attrs + size[0];
1505
1506 sect_attrs->nsections = 0;
1507 sattr = &sect_attrs->attrs[0];
1508 gattr = &sect_attrs->grp.attrs[0];
1509 for (i = 0; i < info->hdr->e_shnum; i++) {
1510 Elf_Shdr *sec = &info->sechdrs[i];
1511 if (sect_empty(sec))
1512 continue;
1513 sattr->address = sec->sh_addr;
1514 sattr->name = kstrdup(info->secstrings + sec->sh_name,
1515 GFP_KERNEL);
1516 if (sattr->name == NULL)
1517 goto out;
1518 sect_attrs->nsections++;
1519 sysfs_attr_init(&sattr->mattr.attr);
1520 sattr->mattr.show = module_sect_show;
1521 sattr->mattr.store = NULL;
1522 sattr->mattr.attr.name = sattr->name;
1523 sattr->mattr.attr.mode = S_IRUSR;
1524 *(gattr++) = &(sattr++)->mattr.attr;
1525 }
1526 *gattr = NULL;
1527
1528 if (sysfs_create_group(&mod->mkobj.kobj, &sect_attrs->grp))
1529 goto out;
1530
1531 mod->sect_attrs = sect_attrs;
1532 return;
1533 out:
1534 free_sect_attrs(sect_attrs);
1535}
1536
1537static void remove_sect_attrs(struct module *mod)
1538{
1539 if (mod->sect_attrs) {
1540 sysfs_remove_group(&mod->mkobj.kobj,
1541 &mod->sect_attrs->grp);
1542 /* We are positive that no one is using any sect attrs
1543 * at this point. Deallocate immediately. */
1544 free_sect_attrs(mod->sect_attrs);
1545 mod->sect_attrs = NULL;
1546 }
1547}
1548
1549/*
1550 * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
1551 */
1552
1553struct module_notes_attrs {
1554 struct kobject *dir;
1555 unsigned int notes;
1556 struct bin_attribute attrs[0];
1557};
1558
1559static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
1560 struct bin_attribute *bin_attr,
1561 char *buf, loff_t pos, size_t count)
1562{
1563 /*
1564 * The caller checked the pos and count against our size.
1565 */
1566 memcpy(buf, bin_attr->private + pos, count);
1567 return count;
1568}
1569
1570static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
1571 unsigned int i)
1572{
1573 if (notes_attrs->dir) {
1574 while (i-- > 0)
1575 sysfs_remove_bin_file(notes_attrs->dir,
1576 &notes_attrs->attrs[i]);
1577 kobject_put(notes_attrs->dir);
1578 }
1579 kfree(notes_attrs);
1580}
1581
1582static void add_notes_attrs(struct module *mod, const struct load_info *info)
1583{
1584 unsigned int notes, loaded, i;
1585 struct module_notes_attrs *notes_attrs;
1586 struct bin_attribute *nattr;
1587
1588 /* failed to create section attributes, so can't create notes */
1589 if (!mod->sect_attrs)
1590 return;
1591
1592 /* Count notes sections and allocate structures. */
1593 notes = 0;
1594 for (i = 0; i < info->hdr->e_shnum; i++)
1595 if (!sect_empty(&info->sechdrs[i]) &&
1596 (info->sechdrs[i].sh_type == SHT_NOTE))
1597 ++notes;
1598
1599 if (notes == 0)
1600 return;
1601
1602 notes_attrs = kzalloc(struct_size(notes_attrs, attrs, notes),
1603 GFP_KERNEL);
1604 if (notes_attrs == NULL)
1605 return;
1606
1607 notes_attrs->notes = notes;
1608 nattr = &notes_attrs->attrs[0];
1609 for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
1610 if (sect_empty(&info->sechdrs[i]))
1611 continue;
1612 if (info->sechdrs[i].sh_type == SHT_NOTE) {
1613 sysfs_bin_attr_init(nattr);
1614 nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
1615 nattr->attr.mode = S_IRUGO;
1616 nattr->size = info->sechdrs[i].sh_size;
1617 nattr->private = (void *) info->sechdrs[i].sh_addr;
1618 nattr->read = module_notes_read;
1619 ++nattr;
1620 }
1621 ++loaded;
1622 }
1623
1624 notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
1625 if (!notes_attrs->dir)
1626 goto out;
1627
1628 for (i = 0; i < notes; ++i)
1629 if (sysfs_create_bin_file(notes_attrs->dir,
1630 &notes_attrs->attrs[i]))
1631 goto out;
1632
1633 mod->notes_attrs = notes_attrs;
1634 return;
1635
1636 out:
1637 free_notes_attrs(notes_attrs, i);
1638}
1639
1640static void remove_notes_attrs(struct module *mod)
1641{
1642 if (mod->notes_attrs)
1643 free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
1644}
1645
1646#else
1647
1648static inline void add_sect_attrs(struct module *mod,
1649 const struct load_info *info)
1650{
1651}
1652
1653static inline void remove_sect_attrs(struct module *mod)
1654{
1655}
1656
1657static inline void add_notes_attrs(struct module *mod,
1658 const struct load_info *info)
1659{
1660}
1661
1662static inline void remove_notes_attrs(struct module *mod)
1663{
1664}
1665#endif /* CONFIG_KALLSYMS */
1666
1667static void del_usage_links(struct module *mod)
1668{
1669#ifdef CONFIG_MODULE_UNLOAD
1670 struct module_use *use;
1671
1672 mutex_lock(&module_mutex);
1673 list_for_each_entry(use, &mod->target_list, target_list)
1674 sysfs_remove_link(use->target->holders_dir, mod->name);
1675 mutex_unlock(&module_mutex);
1676#endif
1677}
1678
1679static int add_usage_links(struct module *mod)
1680{
1681 int ret = 0;
1682#ifdef CONFIG_MODULE_UNLOAD
1683 struct module_use *use;
1684
1685 mutex_lock(&module_mutex);
1686 list_for_each_entry(use, &mod->target_list, target_list) {
1687 ret = sysfs_create_link(use->target->holders_dir,
1688 &mod->mkobj.kobj, mod->name);
1689 if (ret)
1690 break;
1691 }
1692 mutex_unlock(&module_mutex);
1693 if (ret)
1694 del_usage_links(mod);
1695#endif
1696 return ret;
1697}
1698
1699static void module_remove_modinfo_attrs(struct module *mod, int end);
1700
1701static int module_add_modinfo_attrs(struct module *mod)
1702{
1703 struct module_attribute *attr;
1704 struct module_attribute *temp_attr;
1705 int error = 0;
1706 int i;
1707
1708 mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
1709 (ARRAY_SIZE(modinfo_attrs) + 1)),
1710 GFP_KERNEL);
1711 if (!mod->modinfo_attrs)
1712 return -ENOMEM;
1713
1714 temp_attr = mod->modinfo_attrs;
1715 for (i = 0; (attr = modinfo_attrs[i]); i++) {
1716 if (!attr->test || attr->test(mod)) {
1717 memcpy(temp_attr, attr, sizeof(*temp_attr));
1718 sysfs_attr_init(&temp_attr->attr);
1719 error = sysfs_create_file(&mod->mkobj.kobj,
1720 &temp_attr->attr);
1721 if (error)
1722 goto error_out;
1723 ++temp_attr;
1724 }
1725 }
1726
1727 return 0;
1728
1729error_out:
1730 if (i > 0)
1731 module_remove_modinfo_attrs(mod, --i);
1732 return error;
1733}
1734
1735static void module_remove_modinfo_attrs(struct module *mod, int end)
1736{
1737 struct module_attribute *attr;
1738 int i;
1739
1740 for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
1741 if (end >= 0 && i > end)
1742 break;
1743 /* pick a field to test for end of list */
1744 if (!attr->attr.name)
1745 break;
1746 sysfs_remove_file(&mod->mkobj.kobj, &attr->attr);
1747 if (attr->free)
1748 attr->free(mod);
1749 }
1750 kfree(mod->modinfo_attrs);
1751}
1752
1753static void mod_kobject_put(struct module *mod)
1754{
1755 DECLARE_COMPLETION_ONSTACK(c);
1756 mod->mkobj.kobj_completion = &c;
1757 kobject_put(&mod->mkobj.kobj);
1758 wait_for_completion(&c);
1759}
1760
1761static int mod_sysfs_init(struct module *mod)
1762{
1763 int err;
1764 struct kobject *kobj;
1765
1766 if (!module_sysfs_initialized) {
1767 pr_err("%s: module sysfs not initialized\n", mod->name);
1768 err = -EINVAL;
1769 goto out;
1770 }
1771
1772 kobj = kset_find_obj(module_kset, mod->name);
1773 if (kobj) {
1774 pr_err("%s: module is already loaded\n", mod->name);
1775 kobject_put(kobj);
1776 err = -EINVAL;
1777 goto out;
1778 }
1779
1780 mod->mkobj.mod = mod;
1781
1782 memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
1783 mod->mkobj.kobj.kset = module_kset;
1784 err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
1785 "%s", mod->name);
1786 if (err)
1787 mod_kobject_put(mod);
1788
1789 /* delay uevent until full sysfs population */
1790out:
1791 return err;
1792}
1793
1794static int mod_sysfs_setup(struct module *mod,
1795 const struct load_info *info,
1796 struct kernel_param *kparam,
1797 unsigned int num_params)
1798{
1799 int err;
1800
1801 err = mod_sysfs_init(mod);
1802 if (err)
1803 goto out;
1804
1805 mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1806 if (!mod->holders_dir) {
1807 err = -ENOMEM;
1808 goto out_unreg;
1809 }
1810
1811 err = module_param_sysfs_setup(mod, kparam, num_params);
1812 if (err)
1813 goto out_unreg_holders;
1814
1815 err = module_add_modinfo_attrs(mod);
1816 if (err)
1817 goto out_unreg_param;
1818
1819 err = add_usage_links(mod);
1820 if (err)
1821 goto out_unreg_modinfo_attrs;
1822
1823 add_sect_attrs(mod, info);
1824 add_notes_attrs(mod, info);
1825
1826 kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
1827 return 0;
1828
1829out_unreg_modinfo_attrs:
1830 module_remove_modinfo_attrs(mod, -1);
1831out_unreg_param:
1832 module_param_sysfs_remove(mod);
1833out_unreg_holders:
1834 kobject_put(mod->holders_dir);
1835out_unreg:
1836 mod_kobject_put(mod);
1837out:
1838 return err;
1839}
1840
1841static void mod_sysfs_fini(struct module *mod)
1842{
1843 remove_notes_attrs(mod);
1844 remove_sect_attrs(mod);
1845 mod_kobject_put(mod);
1846}
1847
1848static void init_param_lock(struct module *mod)
1849{
1850 mutex_init(&mod->param_lock);
1851}
1852#else /* !CONFIG_SYSFS */
1853
1854static int mod_sysfs_setup(struct module *mod,
1855 const struct load_info *info,
1856 struct kernel_param *kparam,
1857 unsigned int num_params)
1858{
1859 return 0;
1860}
1861
1862static void mod_sysfs_fini(struct module *mod)
1863{
1864}
1865
1866static void module_remove_modinfo_attrs(struct module *mod, int end)
1867{
1868}
1869
1870static void del_usage_links(struct module *mod)
1871{
1872}
1873
1874static void init_param_lock(struct module *mod)
1875{
1876}
1877#endif /* CONFIG_SYSFS */
1878
1879static void mod_sysfs_teardown(struct module *mod)
1880{
1881 del_usage_links(mod);
1882 module_remove_modinfo_attrs(mod, -1);
1883 module_param_sysfs_remove(mod);
1884 kobject_put(mod->mkobj.drivers_dir);
1885 kobject_put(mod->holders_dir);
1886 mod_sysfs_fini(mod);
1887}
1888
1889#ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX
1890/*
1891 * LKM RO/NX protection: protect module's text/ro-data
1892 * from modification and any data from execution.
1893 *
1894 * General layout of module is:
1895 * [text] [read-only-data] [ro-after-init] [writable data]
1896 * text_size -----^ ^ ^ ^
1897 * ro_size ------------------------| | |
1898 * ro_after_init_size -----------------------------| |
1899 * size -----------------------------------------------------------|
1900 *
1901 * These values are always page-aligned (as is base)
1902 */
1903static void frob_text(const struct module_layout *layout,
1904 int (*set_memory)(unsigned long start, int num_pages))
1905{
1906 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1907 BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
1908 set_memory((unsigned long)layout->base,
1909 layout->text_size >> PAGE_SHIFT);
1910}
1911
1912#ifdef CONFIG_STRICT_MODULE_RWX
1913static void frob_rodata(const struct module_layout *layout,
1914 int (*set_memory)(unsigned long start, int num_pages))
1915{
1916 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1917 BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
1918 BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
1919 set_memory((unsigned long)layout->base + layout->text_size,
1920 (layout->ro_size - layout->text_size) >> PAGE_SHIFT);
1921}
1922
1923static void frob_ro_after_init(const struct module_layout *layout,
1924 int (*set_memory)(unsigned long start, int num_pages))
1925{
1926 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1927 BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
1928 BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
1929 set_memory((unsigned long)layout->base + layout->ro_size,
1930 (layout->ro_after_init_size - layout->ro_size) >> PAGE_SHIFT);
1931}
1932
1933static void frob_writable_data(const struct module_layout *layout,
1934 int (*set_memory)(unsigned long start, int num_pages))
1935{
1936 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1937 BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
1938 BUG_ON((unsigned long)layout->size & (PAGE_SIZE-1));
1939 set_memory((unsigned long)layout->base + layout->ro_after_init_size,
1940 (layout->size - layout->ro_after_init_size) >> PAGE_SHIFT);
1941}
1942
1943/* livepatching wants to disable read-only so it can frob module. */
1944void module_disable_ro(const struct module *mod)
1945{
1946 if (!rodata_enabled)
1947 return;
1948
1949 frob_text(&mod->core_layout, set_memory_rw);
1950 frob_rodata(&mod->core_layout, set_memory_rw);
1951 frob_ro_after_init(&mod->core_layout, set_memory_rw);
1952 frob_text(&mod->init_layout, set_memory_rw);
1953 frob_rodata(&mod->init_layout, set_memory_rw);
1954}
1955
1956void module_enable_ro(const struct module *mod, bool after_init)
1957{
1958 if (!rodata_enabled)
1959 return;
1960
1961 set_vm_flush_reset_perms(mod->core_layout.base);
1962 set_vm_flush_reset_perms(mod->init_layout.base);
1963 frob_text(&mod->core_layout, set_memory_ro);
1964
1965 frob_rodata(&mod->core_layout, set_memory_ro);
1966 frob_text(&mod->init_layout, set_memory_ro);
1967 frob_rodata(&mod->init_layout, set_memory_ro);
1968
1969 if (after_init)
1970 frob_ro_after_init(&mod->core_layout, set_memory_ro);
1971}
1972
1973static void module_enable_nx(const struct module *mod)
1974{
1975 frob_rodata(&mod->core_layout, set_memory_nx);
1976 frob_ro_after_init(&mod->core_layout, set_memory_nx);
1977 frob_writable_data(&mod->core_layout, set_memory_nx);
1978 frob_rodata(&mod->init_layout, set_memory_nx);
1979 frob_writable_data(&mod->init_layout, set_memory_nx);
1980}
1981
1982/* Iterate through all modules and set each module's text as RW */
1983void set_all_modules_text_rw(void)
1984{
1985 struct module *mod;
1986
1987 if (!rodata_enabled)
1988 return;
1989
1990 mutex_lock(&module_mutex);
1991 list_for_each_entry_rcu(mod, &modules, list) {
1992 if (mod->state == MODULE_STATE_UNFORMED)
1993 continue;
1994
1995 frob_text(&mod->core_layout, set_memory_rw);
1996 frob_text(&mod->init_layout, set_memory_rw);
1997 }
1998 mutex_unlock(&module_mutex);
1999}
2000
2001/* Iterate through all modules and set each module's text as RO */
2002void set_all_modules_text_ro(void)
2003{
2004 struct module *mod;
2005
2006 if (!rodata_enabled)
2007 return;
2008
2009 mutex_lock(&module_mutex);
2010 list_for_each_entry_rcu(mod, &modules, list) {
2011 /*
2012 * Ignore going modules since it's possible that ro
2013 * protection has already been disabled, otherwise we'll
2014 * run into protection faults at module deallocation.
2015 */
2016 if (mod->state == MODULE_STATE_UNFORMED ||
2017 mod->state == MODULE_STATE_GOING)
2018 continue;
2019
2020 frob_text(&mod->core_layout, set_memory_ro);
2021 frob_text(&mod->init_layout, set_memory_ro);
2022 }
2023 mutex_unlock(&module_mutex);
2024}
2025#else /* !CONFIG_STRICT_MODULE_RWX */
2026static void module_enable_nx(const struct module *mod) { }
2027#endif /* CONFIG_STRICT_MODULE_RWX */
2028static void module_enable_x(const struct module *mod)
2029{
2030 frob_text(&mod->core_layout, set_memory_x);
2031 frob_text(&mod->init_layout, set_memory_x);
2032}
2033#else /* !CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
2034static void module_enable_nx(const struct module *mod) { }
2035static void module_enable_x(const struct module *mod) { }
2036#endif /* CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
2037
2038
2039#ifdef CONFIG_LIVEPATCH
2040/*
2041 * Persist Elf information about a module. Copy the Elf header,
2042 * section header table, section string table, and symtab section
2043 * index from info to mod->klp_info.
2044 */
2045static int copy_module_elf(struct module *mod, struct load_info *info)
2046{
2047 unsigned int size, symndx;
2048 int ret;
2049
2050 size = sizeof(*mod->klp_info);
2051 mod->klp_info = kmalloc(size, GFP_KERNEL);
2052 if (mod->klp_info == NULL)
2053 return -ENOMEM;
2054
2055 /* Elf header */
2056 size = sizeof(mod->klp_info->hdr);
2057 memcpy(&mod->klp_info->hdr, info->hdr, size);
2058
2059 /* Elf section header table */
2060 size = sizeof(*info->sechdrs) * info->hdr->e_shnum;
2061 mod->klp_info->sechdrs = kmemdup(info->sechdrs, size, GFP_KERNEL);
2062 if (mod->klp_info->sechdrs == NULL) {
2063 ret = -ENOMEM;
2064 goto free_info;
2065 }
2066
2067 /* Elf section name string table */
2068 size = info->sechdrs[info->hdr->e_shstrndx].sh_size;
2069 mod->klp_info->secstrings = kmemdup(info->secstrings, size, GFP_KERNEL);
2070 if (mod->klp_info->secstrings == NULL) {
2071 ret = -ENOMEM;
2072 goto free_sechdrs;
2073 }
2074
2075 /* Elf symbol section index */
2076 symndx = info->index.sym;
2077 mod->klp_info->symndx = symndx;
2078
2079 /*
2080 * For livepatch modules, core_kallsyms.symtab is a complete
2081 * copy of the original symbol table. Adjust sh_addr to point
2082 * to core_kallsyms.symtab since the copy of the symtab in module
2083 * init memory is freed at the end of do_init_module().
2084 */
2085 mod->klp_info->sechdrs[symndx].sh_addr = \
2086 (unsigned long) mod->core_kallsyms.symtab;
2087
2088 return 0;
2089
2090free_sechdrs:
2091 kfree(mod->klp_info->sechdrs);
2092free_info:
2093 kfree(mod->klp_info);
2094 return ret;
2095}
2096
2097static void free_module_elf(struct module *mod)
2098{
2099 kfree(mod->klp_info->sechdrs);
2100 kfree(mod->klp_info->secstrings);
2101 kfree(mod->klp_info);
2102}
2103#else /* !CONFIG_LIVEPATCH */
2104static int copy_module_elf(struct module *mod, struct load_info *info)
2105{
2106 return 0;
2107}
2108
2109static void free_module_elf(struct module *mod)
2110{
2111}
2112#endif /* CONFIG_LIVEPATCH */
2113
2114void __weak module_memfree(void *module_region)
2115{
2116 /*
2117 * This memory may be RO, and freeing RO memory in an interrupt is not
2118 * supported by vmalloc.
2119 */
2120 WARN_ON(in_interrupt());
2121 vfree(module_region);
2122}
2123
2124void __weak module_arch_cleanup(struct module *mod)
2125{
2126}
2127
2128void __weak module_arch_freeing_init(struct module *mod)
2129{
2130}
2131
2132/* Free a module, remove from lists, etc. */
2133static void free_module(struct module *mod)
2134{
2135 trace_module_free(mod);
2136
2137 mod_sysfs_teardown(mod);
2138
2139 /* We leave it in list to prevent duplicate loads, but make sure
2140 * that noone uses it while it's being deconstructed. */
2141 mutex_lock(&module_mutex);
2142 mod->state = MODULE_STATE_UNFORMED;
2143 mutex_unlock(&module_mutex);
2144
2145 /* Remove dynamic debug info */
2146 ddebug_remove_module(mod->name);
2147
2148 /* Arch-specific cleanup. */
2149 module_arch_cleanup(mod);
2150
2151 /* Module unload stuff */
2152 module_unload_free(mod);
2153
2154 /* Free any allocated parameters. */
2155 destroy_params(mod->kp, mod->num_kp);
2156
2157 if (is_livepatch_module(mod))
2158 free_module_elf(mod);
2159
2160 /* Now we can delete it from the lists */
2161 mutex_lock(&module_mutex);
2162 /* Unlink carefully: kallsyms could be walking list. */
2163 list_del_rcu(&mod->list);
2164 mod_tree_remove(mod);
2165 /* Remove this module from bug list, this uses list_del_rcu */
2166 module_bug_cleanup(mod);
2167 /* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */
2168 synchronize_rcu();
2169 mutex_unlock(&module_mutex);
2170
2171 /* This may be empty, but that's OK */
2172 module_arch_freeing_init(mod);
2173 module_memfree(mod->init_layout.base);
2174 kfree(mod->args);
2175 percpu_modfree(mod);
2176
2177 /* Free lock-classes; relies on the preceding sync_rcu(). */
2178 lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
2179
2180 /* Finally, free the core (containing the module structure) */
2181 module_memfree(mod->core_layout.base);
2182}
2183
2184void *__symbol_get(const char *symbol)
2185{
2186 struct module *owner;
2187 const struct kernel_symbol *sym;
2188
2189 preempt_disable();
2190 sym = find_symbol(symbol, &owner, NULL, true, true);
2191 if (sym && strong_try_module_get(owner))
2192 sym = NULL;
2193 preempt_enable();
2194
2195 return sym ? (void *)kernel_symbol_value(sym) : NULL;
2196}
2197EXPORT_SYMBOL_GPL(__symbol_get);
2198
2199/*
2200 * Ensure that an exported symbol [global namespace] does not already exist
2201 * in the kernel or in some other module's exported symbol table.
2202 *
2203 * You must hold the module_mutex.
2204 */
2205static int verify_exported_symbols(struct module *mod)
2206{
2207 unsigned int i;
2208 struct module *owner;
2209 const struct kernel_symbol *s;
2210 struct {
2211 const struct kernel_symbol *sym;
2212 unsigned int num;
2213 } arr[] = {
2214 { mod->syms, mod->num_syms },
2215 { mod->gpl_syms, mod->num_gpl_syms },
2216 { mod->gpl_future_syms, mod->num_gpl_future_syms },
2217#ifdef CONFIG_UNUSED_SYMBOLS
2218 { mod->unused_syms, mod->num_unused_syms },
2219 { mod->unused_gpl_syms, mod->num_unused_gpl_syms },
2220#endif
2221 };
2222
2223 for (i = 0; i < ARRAY_SIZE(arr); i++) {
2224 for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
2225 if (find_symbol(kernel_symbol_name(s), &owner, NULL,
2226 true, false)) {
2227 pr_err("%s: exports duplicate symbol %s"
2228 " (owned by %s)\n",
2229 mod->name, kernel_symbol_name(s),
2230 module_name(owner));
2231 return -ENOEXEC;
2232 }
2233 }
2234 }
2235 return 0;
2236}
2237
2238/* Change all symbols so that st_value encodes the pointer directly. */
2239static int simplify_symbols(struct module *mod, const struct load_info *info)
2240{
2241 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2242 Elf_Sym *sym = (void *)symsec->sh_addr;
2243 unsigned long secbase;
2244 unsigned int i;
2245 int ret = 0;
2246 const struct kernel_symbol *ksym;
2247
2248 for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
2249 const char *name = info->strtab + sym[i].st_name;
2250
2251 switch (sym[i].st_shndx) {
2252 case SHN_COMMON:
2253 /* Ignore common symbols */
2254 if (!strncmp(name, "__gnu_lto", 9))
2255 break;
2256
2257 /* We compiled with -fno-common. These are not
2258 supposed to happen. */
2259 pr_debug("Common symbol: %s\n", name);
2260 pr_warn("%s: please compile with -fno-common\n",
2261 mod->name);
2262 ret = -ENOEXEC;
2263 break;
2264
2265 case SHN_ABS:
2266 /* Don't need to do anything */
2267 pr_debug("Absolute symbol: 0x%08lx\n",
2268 (long)sym[i].st_value);
2269 break;
2270
2271 case SHN_LIVEPATCH:
2272 /* Livepatch symbols are resolved by livepatch */
2273 break;
2274
2275 case SHN_UNDEF:
2276 ksym = resolve_symbol_wait(mod, info, name);
2277 /* Ok if resolved. */
2278 if (ksym && !IS_ERR(ksym)) {
2279 sym[i].st_value = kernel_symbol_value(ksym);
2280 break;
2281 }
2282
2283 /* Ok if weak. */
2284 if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
2285 break;
2286
2287 ret = PTR_ERR(ksym) ?: -ENOENT;
2288 pr_warn("%s: Unknown symbol %s (err %d)\n",
2289 mod->name, name, ret);
2290 break;
2291
2292 default:
2293 /* Divert to percpu allocation if a percpu var. */
2294 if (sym[i].st_shndx == info->index.pcpu)
2295 secbase = (unsigned long)mod_percpu(mod);
2296 else
2297 secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
2298 sym[i].st_value += secbase;
2299 break;
2300 }
2301 }
2302
2303 return ret;
2304}
2305
2306static int apply_relocations(struct module *mod, const struct load_info *info)
2307{
2308 unsigned int i;
2309 int err = 0;
2310
2311 /* Now do relocations. */
2312 for (i = 1; i < info->hdr->e_shnum; i++) {
2313 unsigned int infosec = info->sechdrs[i].sh_info;
2314
2315 /* Not a valid relocation section? */
2316 if (infosec >= info->hdr->e_shnum)
2317 continue;
2318
2319 /* Don't bother with non-allocated sections */
2320 if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
2321 continue;
2322
2323 /* Livepatch relocation sections are applied by livepatch */
2324 if (info->sechdrs[i].sh_flags & SHF_RELA_LIVEPATCH)
2325 continue;
2326
2327 if (info->sechdrs[i].sh_type == SHT_REL)
2328 err = apply_relocate(info->sechdrs, info->strtab,
2329 info->index.sym, i, mod);
2330 else if (info->sechdrs[i].sh_type == SHT_RELA)
2331 err = apply_relocate_add(info->sechdrs, info->strtab,
2332 info->index.sym, i, mod);
2333 if (err < 0)
2334 break;
2335 }
2336 return err;
2337}
2338
2339/* Additional bytes needed by arch in front of individual sections */
2340unsigned int __weak arch_mod_section_prepend(struct module *mod,
2341 unsigned int section)
2342{
2343 /* default implementation just returns zero */
2344 return 0;
2345}
2346
2347/* Update size with this section: return offset. */
2348static long get_offset(struct module *mod, unsigned int *size,
2349 Elf_Shdr *sechdr, unsigned int section)
2350{
2351 long ret;
2352
2353 *size += arch_mod_section_prepend(mod, section);
2354 ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
2355 *size = ret + sechdr->sh_size;
2356 return ret;
2357}
2358
2359/* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
2360 might -- code, read-only data, read-write data, small data. Tally
2361 sizes, and place the offsets into sh_entsize fields: high bit means it
2362 belongs in init. */
2363static void layout_sections(struct module *mod, struct load_info *info)
2364{
2365 static unsigned long const masks[][2] = {
2366 /* NOTE: all executable code must be the first section
2367 * in this array; otherwise modify the text_size
2368 * finder in the two loops below */
2369 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
2370 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
2371 { SHF_RO_AFTER_INIT | SHF_ALLOC, ARCH_SHF_SMALL },
2372 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
2373 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
2374 };
2375 unsigned int m, i;
2376
2377 for (i = 0; i < info->hdr->e_shnum; i++)
2378 info->sechdrs[i].sh_entsize = ~0UL;
2379
2380 pr_debug("Core section allocation order:\n");
2381 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2382 for (i = 0; i < info->hdr->e_shnum; ++i) {
2383 Elf_Shdr *s = &info->sechdrs[i];
2384 const char *sname = info->secstrings + s->sh_name;
2385
2386 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2387 || (s->sh_flags & masks[m][1])
2388 || s->sh_entsize != ~0UL
2389 || strstarts(sname, ".init"))
2390 continue;
2391 s->sh_entsize = get_offset(mod, &mod->core_layout.size, s, i);
2392 pr_debug("\t%s\n", sname);
2393 }
2394 switch (m) {
2395 case 0: /* executable */
2396 mod->core_layout.size = debug_align(mod->core_layout.size);
2397 mod->core_layout.text_size = mod->core_layout.size;
2398 break;
2399 case 1: /* RO: text and ro-data */
2400 mod->core_layout.size = debug_align(mod->core_layout.size);
2401 mod->core_layout.ro_size = mod->core_layout.size;
2402 break;
2403 case 2: /* RO after init */
2404 mod->core_layout.size = debug_align(mod->core_layout.size);
2405 mod->core_layout.ro_after_init_size = mod->core_layout.size;
2406 break;
2407 case 4: /* whole core */
2408 mod->core_layout.size = debug_align(mod->core_layout.size);
2409 break;
2410 }
2411 }
2412
2413 pr_debug("Init section allocation order:\n");
2414 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2415 for (i = 0; i < info->hdr->e_shnum; ++i) {
2416 Elf_Shdr *s = &info->sechdrs[i];
2417 const char *sname = info->secstrings + s->sh_name;
2418
2419 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2420 || (s->sh_flags & masks[m][1])
2421 || s->sh_entsize != ~0UL
2422 || !strstarts(sname, ".init"))
2423 continue;
2424 s->sh_entsize = (get_offset(mod, &mod->init_layout.size, s, i)
2425 | INIT_OFFSET_MASK);
2426 pr_debug("\t%s\n", sname);
2427 }
2428 switch (m) {
2429 case 0: /* executable */
2430 mod->init_layout.size = debug_align(mod->init_layout.size);
2431 mod->init_layout.text_size = mod->init_layout.size;
2432 break;
2433 case 1: /* RO: text and ro-data */
2434 mod->init_layout.size = debug_align(mod->init_layout.size);
2435 mod->init_layout.ro_size = mod->init_layout.size;
2436 break;
2437 case 2:
2438 /*
2439 * RO after init doesn't apply to init_layout (only
2440 * core_layout), so it just takes the value of ro_size.
2441 */
2442 mod->init_layout.ro_after_init_size = mod->init_layout.ro_size;
2443 break;
2444 case 4: /* whole init */
2445 mod->init_layout.size = debug_align(mod->init_layout.size);
2446 break;
2447 }
2448 }
2449}
2450
2451static void set_license(struct module *mod, const char *license)
2452{
2453 if (!license)
2454 license = "unspecified";
2455
2456 if (!license_is_gpl_compatible(license)) {
2457 if (!test_taint(TAINT_PROPRIETARY_MODULE))
2458 pr_warn("%s: module license '%s' taints kernel.\n",
2459 mod->name, license);
2460 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2461 LOCKDEP_NOW_UNRELIABLE);
2462 }
2463}
2464
2465/* Parse tag=value strings from .modinfo section */
2466static char *next_string(char *string, unsigned long *secsize)
2467{
2468 /* Skip non-zero chars */
2469 while (string[0]) {
2470 string++;
2471 if ((*secsize)-- <= 1)
2472 return NULL;
2473 }
2474
2475 /* Skip any zero padding. */
2476 while (!string[0]) {
2477 string++;
2478 if ((*secsize)-- <= 1)
2479 return NULL;
2480 }
2481 return string;
2482}
2483
2484static char *get_modinfo(struct load_info *info, const char *tag)
2485{
2486 char *p;
2487 unsigned int taglen = strlen(tag);
2488 Elf_Shdr *infosec = &info->sechdrs[info->index.info];
2489 unsigned long size = infosec->sh_size;
2490
2491 /*
2492 * get_modinfo() calls made before rewrite_section_headers()
2493 * must use sh_offset, as sh_addr isn't set!
2494 */
2495 for (p = (char *)info->hdr + infosec->sh_offset; p; p = next_string(p, &size)) {
2496 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
2497 return p + taglen + 1;
2498 }
2499 return NULL;
2500}
2501
2502static void setup_modinfo(struct module *mod, struct load_info *info)
2503{
2504 struct module_attribute *attr;
2505 int i;
2506
2507 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2508 if (attr->setup)
2509 attr->setup(mod, get_modinfo(info, attr->attr.name));
2510 }
2511}
2512
2513static void free_modinfo(struct module *mod)
2514{
2515 struct module_attribute *attr;
2516 int i;
2517
2518 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2519 if (attr->free)
2520 attr->free(mod);
2521 }
2522}
2523
2524#ifdef CONFIG_KALLSYMS
2525
2526/* Lookup exported symbol in given range of kernel_symbols */
2527static const struct kernel_symbol *lookup_exported_symbol(const char *name,
2528 const struct kernel_symbol *start,
2529 const struct kernel_symbol *stop)
2530{
2531 return bsearch(name, start, stop - start,
2532 sizeof(struct kernel_symbol), cmp_name);
2533}
2534
2535static int is_exported(const char *name, unsigned long value,
2536 const struct module *mod)
2537{
2538 const struct kernel_symbol *ks;
2539 if (!mod)
2540 ks = lookup_exported_symbol(name, __start___ksymtab, __stop___ksymtab);
2541 else
2542 ks = lookup_exported_symbol(name, mod->syms, mod->syms + mod->num_syms);
2543
2544 return ks != NULL && kernel_symbol_value(ks) == value;
2545}
2546
2547/* As per nm */
2548static char elf_type(const Elf_Sym *sym, const struct load_info *info)
2549{
2550 const Elf_Shdr *sechdrs = info->sechdrs;
2551
2552 if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
2553 if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
2554 return 'v';
2555 else
2556 return 'w';
2557 }
2558 if (sym->st_shndx == SHN_UNDEF)
2559 return 'U';
2560 if (sym->st_shndx == SHN_ABS || sym->st_shndx == info->index.pcpu)
2561 return 'a';
2562 if (sym->st_shndx >= SHN_LORESERVE)
2563 return '?';
2564 if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
2565 return 't';
2566 if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
2567 && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
2568 if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
2569 return 'r';
2570 else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2571 return 'g';
2572 else
2573 return 'd';
2574 }
2575 if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
2576 if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2577 return 's';
2578 else
2579 return 'b';
2580 }
2581 if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
2582 ".debug")) {
2583 return 'n';
2584 }
2585 return '?';
2586}
2587
2588static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
2589 unsigned int shnum, unsigned int pcpundx)
2590{
2591 const Elf_Shdr *sec;
2592
2593 if (src->st_shndx == SHN_UNDEF
2594 || src->st_shndx >= shnum
2595 || !src->st_name)
2596 return false;
2597
2598#ifdef CONFIG_KALLSYMS_ALL
2599 if (src->st_shndx == pcpundx)
2600 return true;
2601#endif
2602
2603 sec = sechdrs + src->st_shndx;
2604 if (!(sec->sh_flags & SHF_ALLOC)
2605#ifndef CONFIG_KALLSYMS_ALL
2606 || !(sec->sh_flags & SHF_EXECINSTR)
2607#endif
2608 || (sec->sh_entsize & INIT_OFFSET_MASK))
2609 return false;
2610
2611 return true;
2612}
2613
2614/*
2615 * We only allocate and copy the strings needed by the parts of symtab
2616 * we keep. This is simple, but has the effect of making multiple
2617 * copies of duplicates. We could be more sophisticated, see
2618 * linux-kernel thread starting with
2619 * <73defb5e4bca04a6431392cc341112b1@localhost>.
2620 */
2621static void layout_symtab(struct module *mod, struct load_info *info)
2622{
2623 Elf_Shdr *symsect = info->sechdrs + info->index.sym;
2624 Elf_Shdr *strsect = info->sechdrs + info->index.str;
2625 const Elf_Sym *src;
2626 unsigned int i, nsrc, ndst, strtab_size = 0;
2627
2628 /* Put symbol section at end of init part of module. */
2629 symsect->sh_flags |= SHF_ALLOC;
2630 symsect->sh_entsize = get_offset(mod, &mod->init_layout.size, symsect,
2631 info->index.sym) | INIT_OFFSET_MASK;
2632 pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
2633
2634 src = (void *)info->hdr + symsect->sh_offset;
2635 nsrc = symsect->sh_size / sizeof(*src);
2636
2637 /* Compute total space required for the core symbols' strtab. */
2638 for (ndst = i = 0; i < nsrc; i++) {
2639 if (i == 0 || is_livepatch_module(mod) ||
2640 is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
2641 info->index.pcpu)) {
2642 strtab_size += strlen(&info->strtab[src[i].st_name])+1;
2643 ndst++;
2644 }
2645 }
2646
2647 /* Append room for core symbols at end of core part. */
2648 info->symoffs = ALIGN(mod->core_layout.size, symsect->sh_addralign ?: 1);
2649 info->stroffs = mod->core_layout.size = info->symoffs + ndst * sizeof(Elf_Sym);
2650 mod->core_layout.size += strtab_size;
2651 info->core_typeoffs = mod->core_layout.size;
2652 mod->core_layout.size += ndst * sizeof(char);
2653 mod->core_layout.size = debug_align(mod->core_layout.size);
2654
2655 /* Put string table section at end of init part of module. */
2656 strsect->sh_flags |= SHF_ALLOC;
2657 strsect->sh_entsize = get_offset(mod, &mod->init_layout.size, strsect,
2658 info->index.str) | INIT_OFFSET_MASK;
2659 pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
2660
2661 /* We'll tack temporary mod_kallsyms on the end. */
2662 mod->init_layout.size = ALIGN(mod->init_layout.size,
2663 __alignof__(struct mod_kallsyms));
2664 info->mod_kallsyms_init_off = mod->init_layout.size;
2665 mod->init_layout.size += sizeof(struct mod_kallsyms);
2666 info->init_typeoffs = mod->init_layout.size;
2667 mod->init_layout.size += nsrc * sizeof(char);
2668 mod->init_layout.size = debug_align(mod->init_layout.size);
2669}
2670
2671/*
2672 * We use the full symtab and strtab which layout_symtab arranged to
2673 * be appended to the init section. Later we switch to the cut-down
2674 * core-only ones.
2675 */
2676static void add_kallsyms(struct module *mod, const struct load_info *info)
2677{
2678 unsigned int i, ndst;
2679 const Elf_Sym *src;
2680 Elf_Sym *dst;
2681 char *s;
2682 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2683
2684 /* Set up to point into init section. */
2685 mod->kallsyms = mod->init_layout.base + info->mod_kallsyms_init_off;
2686
2687 mod->kallsyms->symtab = (void *)symsec->sh_addr;
2688 mod->kallsyms->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
2689 /* Make sure we get permanent strtab: don't use info->strtab. */
2690 mod->kallsyms->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
2691 mod->kallsyms->typetab = mod->init_layout.base + info->init_typeoffs;
2692
2693 /*
2694 * Now populate the cut down core kallsyms for after init
2695 * and set types up while we still have access to sections.
2696 */
2697 mod->core_kallsyms.symtab = dst = mod->core_layout.base + info->symoffs;
2698 mod->core_kallsyms.strtab = s = mod->core_layout.base + info->stroffs;
2699 mod->core_kallsyms.typetab = mod->core_layout.base + info->core_typeoffs;
2700 src = mod->kallsyms->symtab;
2701 for (ndst = i = 0; i < mod->kallsyms->num_symtab; i++) {
2702 mod->kallsyms->typetab[i] = elf_type(src + i, info);
2703 if (i == 0 || is_livepatch_module(mod) ||
2704 is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
2705 info->index.pcpu)) {
2706 mod->core_kallsyms.typetab[ndst] =
2707 mod->kallsyms->typetab[i];
2708 dst[ndst] = src[i];
2709 dst[ndst++].st_name = s - mod->core_kallsyms.strtab;
2710 s += strlcpy(s, &mod->kallsyms->strtab[src[i].st_name],
2711 KSYM_NAME_LEN) + 1;
2712 }
2713 }
2714 mod->core_kallsyms.num_symtab = ndst;
2715}
2716#else
2717static inline void layout_symtab(struct module *mod, struct load_info *info)
2718{
2719}
2720
2721static void add_kallsyms(struct module *mod, const struct load_info *info)
2722{
2723}
2724#endif /* CONFIG_KALLSYMS */
2725
2726static void dynamic_debug_setup(struct module *mod, struct _ddebug *debug, unsigned int num)
2727{
2728 if (!debug)
2729 return;
2730 ddebug_add_module(debug, num, mod->name);
2731}
2732
2733static void dynamic_debug_remove(struct module *mod, struct _ddebug *debug)
2734{
2735 if (debug)
2736 ddebug_remove_module(mod->name);
2737}
2738
2739void * __weak module_alloc(unsigned long size)
2740{
2741 return vmalloc_exec(size);
2742}
2743
2744bool __weak module_exit_section(const char *name)
2745{
2746 return strstarts(name, ".exit");
2747}
2748
2749#ifdef CONFIG_DEBUG_KMEMLEAK
2750static void kmemleak_load_module(const struct module *mod,
2751 const struct load_info *info)
2752{
2753 unsigned int i;
2754
2755 /* only scan the sections containing data */
2756 kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
2757
2758 for (i = 1; i < info->hdr->e_shnum; i++) {
2759 /* Scan all writable sections that's not executable */
2760 if (!(info->sechdrs[i].sh_flags & SHF_ALLOC) ||
2761 !(info->sechdrs[i].sh_flags & SHF_WRITE) ||
2762 (info->sechdrs[i].sh_flags & SHF_EXECINSTR))
2763 continue;
2764
2765 kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
2766 info->sechdrs[i].sh_size, GFP_KERNEL);
2767 }
2768}
2769#else
2770static inline void kmemleak_load_module(const struct module *mod,
2771 const struct load_info *info)
2772{
2773}
2774#endif
2775
2776#ifdef CONFIG_MODULE_SIG
2777static int module_sig_check(struct load_info *info, int flags)
2778{
2779 int err = -ENOKEY;
2780 const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
2781 const void *mod = info->hdr;
2782
2783 /*
2784 * Require flags == 0, as a module with version information
2785 * removed is no longer the module that was signed
2786 */
2787 if (flags == 0 &&
2788 info->len > markerlen &&
2789 memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
2790 /* We truncate the module to discard the signature */
2791 info->len -= markerlen;
2792 err = mod_verify_sig(mod, info);
2793 }
2794
2795 if (!err) {
2796 info->sig_ok = true;
2797 return 0;
2798 }
2799
2800 /* Not having a signature is only an error if we're strict. */
2801 if (err == -ENOKEY && !is_module_sig_enforced())
2802 err = 0;
2803
2804 return err;
2805}
2806#else /* !CONFIG_MODULE_SIG */
2807static int module_sig_check(struct load_info *info, int flags)
2808{
2809 return 0;
2810}
2811#endif /* !CONFIG_MODULE_SIG */
2812
2813/* Sanity checks against invalid binaries, wrong arch, weird elf version. */
2814static int elf_header_check(struct load_info *info)
2815{
2816 if (info->len < sizeof(*(info->hdr)))
2817 return -ENOEXEC;
2818
2819 if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0
2820 || info->hdr->e_type != ET_REL
2821 || !elf_check_arch(info->hdr)
2822 || info->hdr->e_shentsize != sizeof(Elf_Shdr))
2823 return -ENOEXEC;
2824
2825 if (info->hdr->e_shoff >= info->len
2826 || (info->hdr->e_shnum * sizeof(Elf_Shdr) >
2827 info->len - info->hdr->e_shoff))
2828 return -ENOEXEC;
2829
2830 return 0;
2831}
2832
2833#define COPY_CHUNK_SIZE (16*PAGE_SIZE)
2834
2835static int copy_chunked_from_user(void *dst, const void __user *usrc, unsigned long len)
2836{
2837 do {
2838 unsigned long n = min(len, COPY_CHUNK_SIZE);
2839
2840 if (copy_from_user(dst, usrc, n) != 0)
2841 return -EFAULT;
2842 cond_resched();
2843 dst += n;
2844 usrc += n;
2845 len -= n;
2846 } while (len);
2847 return 0;
2848}
2849
2850#ifdef CONFIG_LIVEPATCH
2851static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
2852{
2853 if (get_modinfo(info, "livepatch")) {
2854 mod->klp = true;
2855 add_taint_module(mod, TAINT_LIVEPATCH, LOCKDEP_STILL_OK);
2856 pr_notice_once("%s: tainting kernel with TAINT_LIVEPATCH\n",
2857 mod->name);
2858 }
2859
2860 return 0;
2861}
2862#else /* !CONFIG_LIVEPATCH */
2863static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
2864{
2865 if (get_modinfo(info, "livepatch")) {
2866 pr_err("%s: module is marked as livepatch module, but livepatch support is disabled",
2867 mod->name);
2868 return -ENOEXEC;
2869 }
2870
2871 return 0;
2872}
2873#endif /* CONFIG_LIVEPATCH */
2874
2875static void check_modinfo_retpoline(struct module *mod, struct load_info *info)
2876{
2877 if (retpoline_module_ok(get_modinfo(info, "retpoline")))
2878 return;
2879
2880 pr_warn("%s: loading module not compiled with retpoline compiler.\n",
2881 mod->name);
2882}
2883
2884/* Sets info->hdr and info->len. */
2885static int copy_module_from_user(const void __user *umod, unsigned long len,
2886 struct load_info *info)
2887{
2888 int err;
2889
2890 info->len = len;
2891 if (info->len < sizeof(*(info->hdr)))
2892 return -ENOEXEC;
2893
2894 err = security_kernel_load_data(LOADING_MODULE);
2895 if (err)
2896 return err;
2897
2898 /* Suck in entire file: we'll want most of it. */
2899 info->hdr = __vmalloc(info->len,
2900 GFP_KERNEL | __GFP_NOWARN, PAGE_KERNEL);
2901 if (!info->hdr)
2902 return -ENOMEM;
2903
2904 if (copy_chunked_from_user(info->hdr, umod, info->len) != 0) {
2905 vfree(info->hdr);
2906 return -EFAULT;
2907 }
2908
2909 return 0;
2910}
2911
2912static void free_copy(struct load_info *info)
2913{
2914 vfree(info->hdr);
2915}
2916
2917static int rewrite_section_headers(struct load_info *info, int flags)
2918{
2919 unsigned int i;
2920
2921 /* This should always be true, but let's be sure. */
2922 info->sechdrs[0].sh_addr = 0;
2923
2924 for (i = 1; i < info->hdr->e_shnum; i++) {
2925 Elf_Shdr *shdr = &info->sechdrs[i];
2926 if (shdr->sh_type != SHT_NOBITS
2927 && info->len < shdr->sh_offset + shdr->sh_size) {
2928 pr_err("Module len %lu truncated\n", info->len);
2929 return -ENOEXEC;
2930 }
2931
2932 /* Mark all sections sh_addr with their address in the
2933 temporary image. */
2934 shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
2935
2936#ifndef CONFIG_MODULE_UNLOAD
2937 /* Don't load .exit sections */
2938 if (module_exit_section(info->secstrings+shdr->sh_name))
2939 shdr->sh_flags &= ~(unsigned long)SHF_ALLOC;
2940#endif
2941 }
2942
2943 /* Track but don't keep modinfo and version sections. */
2944 info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
2945 info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
2946
2947 return 0;
2948}
2949
2950/*
2951 * Set up our basic convenience variables (pointers to section headers,
2952 * search for module section index etc), and do some basic section
2953 * verification.
2954 *
2955 * Set info->mod to the temporary copy of the module in info->hdr. The final one
2956 * will be allocated in move_module().
2957 */
2958static int setup_load_info(struct load_info *info, int flags)
2959{
2960 unsigned int i;
2961
2962 /* Set up the convenience variables */
2963 info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
2964 info->secstrings = (void *)info->hdr
2965 + info->sechdrs[info->hdr->e_shstrndx].sh_offset;
2966
2967 /* Try to find a name early so we can log errors with a module name */
2968 info->index.info = find_sec(info, ".modinfo");
2969 if (!info->index.info)
2970 info->name = "(missing .modinfo section)";
2971 else
2972 info->name = get_modinfo(info, "name");
2973
2974 /* Find internal symbols and strings. */
2975 for (i = 1; i < info->hdr->e_shnum; i++) {
2976 if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
2977 info->index.sym = i;
2978 info->index.str = info->sechdrs[i].sh_link;
2979 info->strtab = (char *)info->hdr
2980 + info->sechdrs[info->index.str].sh_offset;
2981 break;
2982 }
2983 }
2984
2985 if (info->index.sym == 0) {
2986 pr_warn("%s: module has no symbols (stripped?)\n", info->name);
2987 return -ENOEXEC;
2988 }
2989
2990 info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
2991 if (!info->index.mod) {
2992 pr_warn("%s: No module found in object\n",
2993 info->name ?: "(missing .modinfo name field)");
2994 return -ENOEXEC;
2995 }
2996 /* This is temporary: point mod into copy of data. */
2997 info->mod = (void *)info->hdr + info->sechdrs[info->index.mod].sh_offset;
2998
2999 /*
3000 * If we didn't load the .modinfo 'name' field earlier, fall back to
3001 * on-disk struct mod 'name' field.
3002 */
3003 if (!info->name)
3004 info->name = info->mod->name;
3005
3006 if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
3007 info->index.vers = 0; /* Pretend no __versions section! */
3008 else
3009 info->index.vers = find_sec(info, "__versions");
3010
3011 info->index.pcpu = find_pcpusec(info);
3012
3013 return 0;
3014}
3015
3016static int check_modinfo(struct module *mod, struct load_info *info, int flags)
3017{
3018 const char *modmagic = get_modinfo(info, "vermagic");
3019 int err;
3020
3021 if (flags & MODULE_INIT_IGNORE_VERMAGIC)
3022 modmagic = NULL;
3023
3024 /* This is allowed: modprobe --force will invalidate it. */
3025 if (!modmagic) {
3026 err = try_to_force_load(mod, "bad vermagic");
3027 if (err)
3028 return err;
3029 } else if (!same_magic(modmagic, vermagic, info->index.vers)) {
3030 pr_err("%s: version magic '%s' should be '%s'\n",
3031 info->name, modmagic, vermagic);
3032 return -ENOEXEC;
3033 }
3034
3035 if (!get_modinfo(info, "intree")) {
3036 if (!test_taint(TAINT_OOT_MODULE))
3037 pr_warn("%s: loading out-of-tree module taints kernel.\n",
3038 mod->name);
3039 add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
3040 }
3041
3042 check_modinfo_retpoline(mod, info);
3043
3044 if (get_modinfo(info, "staging")) {
3045 add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
3046 pr_warn("%s: module is from the staging directory, the quality "
3047 "is unknown, you have been warned.\n", mod->name);
3048 }
3049
3050 err = check_modinfo_livepatch(mod, info);
3051 if (err)
3052 return err;
3053
3054 /* Set up license info based on the info section */
3055 set_license(mod, get_modinfo(info, "license"));
3056
3057 return 0;
3058}
3059
3060static int find_module_sections(struct module *mod, struct load_info *info)
3061{
3062 mod->kp = section_objs(info, "__param",
3063 sizeof(*mod->kp), &mod->num_kp);
3064 mod->syms = section_objs(info, "__ksymtab",
3065 sizeof(*mod->syms), &mod->num_syms);
3066 mod->crcs = section_addr(info, "__kcrctab");
3067 mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
3068 sizeof(*mod->gpl_syms),
3069 &mod->num_gpl_syms);
3070 mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
3071 mod->gpl_future_syms = section_objs(info,
3072 "__ksymtab_gpl_future",
3073 sizeof(*mod->gpl_future_syms),
3074 &mod->num_gpl_future_syms);
3075 mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future");
3076
3077#ifdef CONFIG_UNUSED_SYMBOLS
3078 mod->unused_syms = section_objs(info, "__ksymtab_unused",
3079 sizeof(*mod->unused_syms),
3080 &mod->num_unused_syms);
3081 mod->unused_crcs = section_addr(info, "__kcrctab_unused");
3082 mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl",
3083 sizeof(*mod->unused_gpl_syms),
3084 &mod->num_unused_gpl_syms);
3085 mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl");
3086#endif
3087#ifdef CONFIG_CONSTRUCTORS
3088 mod->ctors = section_objs(info, ".ctors",
3089 sizeof(*mod->ctors), &mod->num_ctors);
3090 if (!mod->ctors)
3091 mod->ctors = section_objs(info, ".init_array",
3092 sizeof(*mod->ctors), &mod->num_ctors);
3093 else if (find_sec(info, ".init_array")) {
3094 /*
3095 * This shouldn't happen with same compiler and binutils
3096 * building all parts of the module.
3097 */
3098 pr_warn("%s: has both .ctors and .init_array.\n",
3099 mod->name);
3100 return -EINVAL;
3101 }
3102#endif
3103
3104#ifdef CONFIG_TRACEPOINTS
3105 mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
3106 sizeof(*mod->tracepoints_ptrs),
3107 &mod->num_tracepoints);
3108#endif
3109#ifdef CONFIG_TREE_SRCU
3110 mod->srcu_struct_ptrs = section_objs(info, "___srcu_struct_ptrs",
3111 sizeof(*mod->srcu_struct_ptrs),
3112 &mod->num_srcu_structs);
3113#endif
3114#ifdef CONFIG_BPF_EVENTS
3115 mod->bpf_raw_events = section_objs(info, "__bpf_raw_tp_map",
3116 sizeof(*mod->bpf_raw_events),
3117 &mod->num_bpf_raw_events);
3118#endif
3119#ifdef CONFIG_JUMP_LABEL
3120 mod->jump_entries = section_objs(info, "__jump_table",
3121 sizeof(*mod->jump_entries),
3122 &mod->num_jump_entries);
3123#endif
3124#ifdef CONFIG_EVENT_TRACING
3125 mod->trace_events = section_objs(info, "_ftrace_events",
3126 sizeof(*mod->trace_events),
3127 &mod->num_trace_events);
3128 mod->trace_evals = section_objs(info, "_ftrace_eval_map",
3129 sizeof(*mod->trace_evals),
3130 &mod->num_trace_evals);
3131#endif
3132#ifdef CONFIG_TRACING
3133 mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
3134 sizeof(*mod->trace_bprintk_fmt_start),
3135 &mod->num_trace_bprintk_fmt);
3136#endif
3137#ifdef CONFIG_FTRACE_MCOUNT_RECORD
3138 /* sechdrs[0].sh_size is always zero */
3139 mod->ftrace_callsites = section_objs(info, "__mcount_loc",
3140 sizeof(*mod->ftrace_callsites),
3141 &mod->num_ftrace_callsites);
3142#endif
3143#ifdef CONFIG_FUNCTION_ERROR_INJECTION
3144 mod->ei_funcs = section_objs(info, "_error_injection_whitelist",
3145 sizeof(*mod->ei_funcs),
3146 &mod->num_ei_funcs);
3147#endif
3148 mod->extable = section_objs(info, "__ex_table",
3149 sizeof(*mod->extable), &mod->num_exentries);
3150
3151 if (section_addr(info, "__obsparm"))
3152 pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
3153
3154 info->debug = section_objs(info, "__verbose",
3155 sizeof(*info->debug), &info->num_debug);
3156
3157 return 0;
3158}
3159
3160static int move_module(struct module *mod, struct load_info *info)
3161{
3162 int i;
3163 void *ptr;
3164
3165 /* Do the allocs. */
3166 ptr = module_alloc(mod->core_layout.size);
3167 /*
3168 * The pointer to this block is stored in the module structure
3169 * which is inside the block. Just mark it as not being a
3170 * leak.
3171 */
3172 kmemleak_not_leak(ptr);
3173 if (!ptr)
3174 return -ENOMEM;
3175
3176 memset(ptr, 0, mod->core_layout.size);
3177 mod->core_layout.base = ptr;
3178
3179 if (mod->init_layout.size) {
3180 ptr = module_alloc(mod->init_layout.size);
3181 /*
3182 * The pointer to this block is stored in the module structure
3183 * which is inside the block. This block doesn't need to be
3184 * scanned as it contains data and code that will be freed
3185 * after the module is initialized.
3186 */
3187 kmemleak_ignore(ptr);
3188 if (!ptr) {
3189 module_memfree(mod->core_layout.base);
3190 return -ENOMEM;
3191 }
3192 memset(ptr, 0, mod->init_layout.size);
3193 mod->init_layout.base = ptr;
3194 } else
3195 mod->init_layout.base = NULL;
3196
3197 /* Transfer each section which specifies SHF_ALLOC */
3198 pr_debug("final section addresses:\n");
3199 for (i = 0; i < info->hdr->e_shnum; i++) {
3200 void *dest;
3201 Elf_Shdr *shdr = &info->sechdrs[i];
3202
3203 if (!(shdr->sh_flags & SHF_ALLOC))
3204 continue;
3205
3206 if (shdr->sh_entsize & INIT_OFFSET_MASK)
3207 dest = mod->init_layout.base
3208 + (shdr->sh_entsize & ~INIT_OFFSET_MASK);
3209 else
3210 dest = mod->core_layout.base + shdr->sh_entsize;
3211
3212 if (shdr->sh_type != SHT_NOBITS)
3213 memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
3214 /* Update sh_addr to point to copy in image. */
3215 shdr->sh_addr = (unsigned long)dest;
3216 pr_debug("\t0x%lx %s\n",
3217 (long)shdr->sh_addr, info->secstrings + shdr->sh_name);
3218 }
3219
3220 return 0;
3221}
3222
3223static int check_module_license_and_versions(struct module *mod)
3224{
3225 int prev_taint = test_taint(TAINT_PROPRIETARY_MODULE);
3226
3227 /*
3228 * ndiswrapper is under GPL by itself, but loads proprietary modules.
3229 * Don't use add_taint_module(), as it would prevent ndiswrapper from
3230 * using GPL-only symbols it needs.
3231 */
3232 if (strcmp(mod->name, "ndiswrapper") == 0)
3233 add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
3234
3235 /* driverloader was caught wrongly pretending to be under GPL */
3236 if (strcmp(mod->name, "driverloader") == 0)
3237 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3238 LOCKDEP_NOW_UNRELIABLE);
3239
3240 /* lve claims to be GPL but upstream won't provide source */
3241 if (strcmp(mod->name, "lve") == 0)
3242 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3243 LOCKDEP_NOW_UNRELIABLE);
3244
3245 if (!prev_taint && test_taint(TAINT_PROPRIETARY_MODULE))
3246 pr_warn("%s: module license taints kernel.\n", mod->name);
3247
3248#ifdef CONFIG_MODVERSIONS
3249 if ((mod->num_syms && !mod->crcs)
3250 || (mod->num_gpl_syms && !mod->gpl_crcs)
3251 || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
3252#ifdef CONFIG_UNUSED_SYMBOLS
3253 || (mod->num_unused_syms && !mod->unused_crcs)
3254 || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
3255#endif
3256 ) {
3257 return try_to_force_load(mod,
3258 "no versions for exported symbols");
3259 }
3260#endif
3261 return 0;
3262}
3263
3264static void flush_module_icache(const struct module *mod)
3265{
3266 mm_segment_t old_fs;
3267
3268 /* flush the icache in correct context */
3269 old_fs = get_fs();
3270 set_fs(KERNEL_DS);
3271
3272 /*
3273 * Flush the instruction cache, since we've played with text.
3274 * Do it before processing of module parameters, so the module
3275 * can provide parameter accessor functions of its own.
3276 */
3277 if (mod->init_layout.base)
3278 flush_icache_range((unsigned long)mod->init_layout.base,
3279 (unsigned long)mod->init_layout.base
3280 + mod->init_layout.size);
3281 flush_icache_range((unsigned long)mod->core_layout.base,
3282 (unsigned long)mod->core_layout.base + mod->core_layout.size);
3283
3284 set_fs(old_fs);
3285}
3286
3287int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
3288 Elf_Shdr *sechdrs,
3289 char *secstrings,
3290 struct module *mod)
3291{
3292 return 0;
3293}
3294
3295/* module_blacklist is a comma-separated list of module names */
3296static char *module_blacklist;
3297static bool blacklisted(const char *module_name)
3298{
3299 const char *p;
3300 size_t len;
3301
3302 if (!module_blacklist)
3303 return false;
3304
3305 for (p = module_blacklist; *p; p += len) {
3306 len = strcspn(p, ",");
3307 if (strlen(module_name) == len && !memcmp(module_name, p, len))
3308 return true;
3309 if (p[len] == ',')
3310 len++;
3311 }
3312 return false;
3313}
3314core_param(module_blacklist, module_blacklist, charp, 0400);
3315
3316static struct module *layout_and_allocate(struct load_info *info, int flags)
3317{
3318 struct module *mod;
3319 unsigned int ndx;
3320 int err;
3321
3322 err = check_modinfo(info->mod, info, flags);
3323 if (err)
3324 return ERR_PTR(err);
3325
3326 /* Allow arches to frob section contents and sizes. */
3327 err = module_frob_arch_sections(info->hdr, info->sechdrs,
3328 info->secstrings, info->mod);
3329 if (err < 0)
3330 return ERR_PTR(err);
3331
3332 /* We will do a special allocation for per-cpu sections later. */
3333 info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC;
3334
3335 /*
3336 * Mark ro_after_init section with SHF_RO_AFTER_INIT so that
3337 * layout_sections() can put it in the right place.
3338 * Note: ro_after_init sections also have SHF_{WRITE,ALLOC} set.
3339 */
3340 ndx = find_sec(info, ".data..ro_after_init");
3341 if (ndx)
3342 info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT;
3343 /*
3344 * Mark the __jump_table section as ro_after_init as well: these data
3345 * structures are never modified, with the exception of entries that
3346 * refer to code in the __init section, which are annotated as such
3347 * at module load time.
3348 */
3349 ndx = find_sec(info, "__jump_table");
3350 if (ndx)
3351 info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT;
3352
3353 /* Determine total sizes, and put offsets in sh_entsize. For now
3354 this is done generically; there doesn't appear to be any
3355 special cases for the architectures. */
3356 layout_sections(info->mod, info);
3357 layout_symtab(info->mod, info);
3358
3359 /* Allocate and move to the final place */
3360 err = move_module(info->mod, info);
3361 if (err)
3362 return ERR_PTR(err);
3363
3364 /* Module has been copied to its final place now: return it. */
3365 mod = (void *)info->sechdrs[info->index.mod].sh_addr;
3366 kmemleak_load_module(mod, info);
3367 return mod;
3368}
3369
3370/* mod is no longer valid after this! */
3371static void module_deallocate(struct module *mod, struct load_info *info)
3372{
3373 percpu_modfree(mod);
3374 module_arch_freeing_init(mod);
3375 module_memfree(mod->init_layout.base);
3376 module_memfree(mod->core_layout.base);
3377}
3378
3379int __weak module_finalize(const Elf_Ehdr *hdr,
3380 const Elf_Shdr *sechdrs,
3381 struct module *me)
3382{
3383 return 0;
3384}
3385
3386static int post_relocation(struct module *mod, const struct load_info *info)
3387{
3388 /* Sort exception table now relocations are done. */
3389 sort_extable(mod->extable, mod->extable + mod->num_exentries);
3390
3391 /* Copy relocated percpu area over. */
3392 percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
3393 info->sechdrs[info->index.pcpu].sh_size);
3394
3395 /* Setup kallsyms-specific fields. */
3396 add_kallsyms(mod, info);
3397
3398 /* Arch-specific module finalizing. */
3399 return module_finalize(info->hdr, info->sechdrs, mod);
3400}
3401
3402/* Is this module of this name done loading? No locks held. */
3403static bool finished_loading(const char *name)
3404{
3405 struct module *mod;
3406 bool ret;
3407
3408 /*
3409 * The module_mutex should not be a heavily contended lock;
3410 * if we get the occasional sleep here, we'll go an extra iteration
3411 * in the wait_event_interruptible(), which is harmless.
3412 */
3413 sched_annotate_sleep();
3414 mutex_lock(&module_mutex);
3415 mod = find_module_all(name, strlen(name), true);
3416 ret = !mod || mod->state == MODULE_STATE_LIVE;
3417 mutex_unlock(&module_mutex);
3418
3419 return ret;
3420}
3421
3422/* Call module constructors. */
3423static void do_mod_ctors(struct module *mod)
3424{
3425#ifdef CONFIG_CONSTRUCTORS
3426 unsigned long i;
3427
3428 for (i = 0; i < mod->num_ctors; i++)
3429 mod->ctors[i]();
3430#endif
3431}
3432
3433/* For freeing module_init on success, in case kallsyms traversing */
3434struct mod_initfree {
3435 struct llist_node node;
3436 void *module_init;
3437};
3438
3439static void do_free_init(struct work_struct *w)
3440{
3441 struct llist_node *pos, *n, *list;
3442 struct mod_initfree *initfree;
3443
3444 list = llist_del_all(&init_free_list);
3445
3446 synchronize_rcu();
3447
3448 llist_for_each_safe(pos, n, list) {
3449 initfree = container_of(pos, struct mod_initfree, node);
3450 module_memfree(initfree->module_init);
3451 kfree(initfree);
3452 }
3453}
3454
3455static int __init modules_wq_init(void)
3456{
3457 INIT_WORK(&init_free_wq, do_free_init);
3458 init_llist_head(&init_free_list);
3459 return 0;
3460}
3461module_init(modules_wq_init);
3462
3463/*
3464 * This is where the real work happens.
3465 *
3466 * Keep it uninlined to provide a reliable breakpoint target, e.g. for the gdb
3467 * helper command 'lx-symbols'.
3468 */
3469static noinline int do_init_module(struct module *mod)
3470{
3471 int ret = 0;
3472 struct mod_initfree *freeinit;
3473
3474 freeinit = kmalloc(sizeof(*freeinit), GFP_KERNEL);
3475 if (!freeinit) {
3476 ret = -ENOMEM;
3477 goto fail;
3478 }
3479 freeinit->module_init = mod->init_layout.base;
3480
3481 /*
3482 * We want to find out whether @mod uses async during init. Clear
3483 * PF_USED_ASYNC. async_schedule*() will set it.
3484 */
3485 current->flags &= ~PF_USED_ASYNC;
3486
3487 do_mod_ctors(mod);
3488 /* Start the module */
3489 if (mod->init != NULL)
3490 ret = do_one_initcall(mod->init);
3491 if (ret < 0) {
3492 goto fail_free_freeinit;
3493 }
3494 if (ret > 0) {
3495 pr_warn("%s: '%s'->init suspiciously returned %d, it should "
3496 "follow 0/-E convention\n"
3497 "%s: loading module anyway...\n",
3498 __func__, mod->name, ret, __func__);
3499 dump_stack();
3500 }
3501
3502 /* Now it's a first class citizen! */
3503 mod->state = MODULE_STATE_LIVE;
3504 blocking_notifier_call_chain(&module_notify_list,
3505 MODULE_STATE_LIVE, mod);
3506
3507 /*
3508 * We need to finish all async code before the module init sequence
3509 * is done. This has potential to deadlock. For example, a newly
3510 * detected block device can trigger request_module() of the
3511 * default iosched from async probing task. Once userland helper
3512 * reaches here, async_synchronize_full() will wait on the async
3513 * task waiting on request_module() and deadlock.
3514 *
3515 * This deadlock is avoided by perfomring async_synchronize_full()
3516 * iff module init queued any async jobs. This isn't a full
3517 * solution as it will deadlock the same if module loading from
3518 * async jobs nests more than once; however, due to the various
3519 * constraints, this hack seems to be the best option for now.
3520 * Please refer to the following thread for details.
3521 *
3522 * http://thread.gmane.org/gmane.linux.kernel/1420814
3523 */
3524 if (!mod->async_probe_requested && (current->flags & PF_USED_ASYNC))
3525 async_synchronize_full();
3526
3527 ftrace_free_mem(mod, mod->init_layout.base, mod->init_layout.base +
3528 mod->init_layout.size);
3529 mutex_lock(&module_mutex);
3530 /* Drop initial reference. */
3531 module_put(mod);
3532 trim_init_extable(mod);
3533#ifdef CONFIG_KALLSYMS
3534 /* Switch to core kallsyms now init is done: kallsyms may be walking! */
3535 rcu_assign_pointer(mod->kallsyms, &mod->core_kallsyms);
3536#endif
3537 module_enable_ro(mod, true);
3538 mod_tree_remove_init(mod);
3539 module_arch_freeing_init(mod);
3540 mod->init_layout.base = NULL;
3541 mod->init_layout.size = 0;
3542 mod->init_layout.ro_size = 0;
3543 mod->init_layout.ro_after_init_size = 0;
3544 mod->init_layout.text_size = 0;
3545 /*
3546 * We want to free module_init, but be aware that kallsyms may be
3547 * walking this with preempt disabled. In all the failure paths, we
3548 * call synchronize_rcu(), but we don't want to slow down the success
3549 * path. module_memfree() cannot be called in an interrupt, so do the
3550 * work and call synchronize_rcu() in a work queue.
3551 *
3552 * Note that module_alloc() on most architectures creates W+X page
3553 * mappings which won't be cleaned up until do_free_init() runs. Any
3554 * code such as mark_rodata_ro() which depends on those mappings to
3555 * be cleaned up needs to sync with the queued work - ie
3556 * rcu_barrier()
3557 */
3558 if (llist_add(&freeinit->node, &init_free_list))
3559 schedule_work(&init_free_wq);
3560
3561 mutex_unlock(&module_mutex);
3562 wake_up_all(&module_wq);
3563
3564 return 0;
3565
3566fail_free_freeinit:
3567 kfree(freeinit);
3568fail:
3569 /* Try to protect us from buggy refcounters. */
3570 mod->state = MODULE_STATE_GOING;
3571 synchronize_rcu();
3572 module_put(mod);
3573 blocking_notifier_call_chain(&module_notify_list,
3574 MODULE_STATE_GOING, mod);
3575 klp_module_going(mod);
3576 ftrace_release_mod(mod);
3577 free_module(mod);
3578 wake_up_all(&module_wq);
3579 return ret;
3580}
3581
3582static int may_init_module(void)
3583{
3584 if (!capable(CAP_SYS_MODULE) || modules_disabled)
3585 return -EPERM;
3586
3587 return 0;
3588}
3589
3590/*
3591 * We try to place it in the list now to make sure it's unique before
3592 * we dedicate too many resources. In particular, temporary percpu
3593 * memory exhaustion.
3594 */
3595static int add_unformed_module(struct module *mod)
3596{
3597 int err;
3598 struct module *old;
3599
3600 mod->state = MODULE_STATE_UNFORMED;
3601
3602again:
3603 mutex_lock(&module_mutex);
3604 old = find_module_all(mod->name, strlen(mod->name), true);
3605 if (old != NULL) {
3606 if (old->state != MODULE_STATE_LIVE) {
3607 /* Wait in case it fails to load. */
3608 mutex_unlock(&module_mutex);
3609 err = wait_event_interruptible(module_wq,
3610 finished_loading(mod->name));
3611 if (err)
3612 goto out_unlocked;
3613 goto again;
3614 }
3615 err = -EEXIST;
3616 goto out;
3617 }
3618 mod_update_bounds(mod);
3619 list_add_rcu(&mod->list, &modules);
3620 mod_tree_insert(mod);
3621 err = 0;
3622
3623out:
3624 mutex_unlock(&module_mutex);
3625out_unlocked:
3626 return err;
3627}
3628
3629static int complete_formation(struct module *mod, struct load_info *info)
3630{
3631 int err;
3632
3633 mutex_lock(&module_mutex);
3634
3635 /* Find duplicate symbols (must be called under lock). */
3636 err = verify_exported_symbols(mod);
3637 if (err < 0)
3638 goto out;
3639
3640 /* This relies on module_mutex for list integrity. */
3641 module_bug_finalize(info->hdr, info->sechdrs, mod);
3642
3643 module_enable_ro(mod, false);
3644 module_enable_nx(mod);
3645 module_enable_x(mod);
3646
3647 /* Mark state as coming so strong_try_module_get() ignores us,
3648 * but kallsyms etc. can see us. */
3649 mod->state = MODULE_STATE_COMING;
3650 mutex_unlock(&module_mutex);
3651
3652 return 0;
3653
3654out:
3655 mutex_unlock(&module_mutex);
3656 return err;
3657}
3658
3659static int prepare_coming_module(struct module *mod)
3660{
3661 int err;
3662
3663 ftrace_module_enable(mod);
3664 err = klp_module_coming(mod);
3665 if (err)
3666 return err;
3667
3668 blocking_notifier_call_chain(&module_notify_list,
3669 MODULE_STATE_COMING, mod);
3670 return 0;
3671}
3672
3673static int unknown_module_param_cb(char *param, char *val, const char *modname,
3674 void *arg)
3675{
3676 struct module *mod = arg;
3677 int ret;
3678
3679 if (strcmp(param, "async_probe") == 0) {
3680 mod->async_probe_requested = true;
3681 return 0;
3682 }
3683
3684 /* Check for magic 'dyndbg' arg */
3685 ret = ddebug_dyndbg_module_param_cb(param, val, modname);
3686 if (ret != 0)
3687 pr_warn("%s: unknown parameter '%s' ignored\n", modname, param);
3688 return 0;
3689}
3690
3691/* Allocate and load the module: note that size of section 0 is always
3692 zero, and we rely on this for optional sections. */
3693static int load_module(struct load_info *info, const char __user *uargs,
3694 int flags)
3695{
3696 struct module *mod;
3697 long err = 0;
3698 char *after_dashes;
3699
3700 err = elf_header_check(info);
3701 if (err)
3702 goto free_copy;
3703
3704 err = setup_load_info(info, flags);
3705 if (err)
3706 goto free_copy;
3707
3708 if (blacklisted(info->name)) {
3709 err = -EPERM;
3710 goto free_copy;
3711 }
3712
3713 err = module_sig_check(info, flags);
3714 if (err)
3715 goto free_copy;
3716
3717 err = rewrite_section_headers(info, flags);
3718 if (err)
3719 goto free_copy;
3720
3721 /* Check module struct version now, before we try to use module. */
3722 if (!check_modstruct_version(info, info->mod)) {
3723 err = -ENOEXEC;
3724 goto free_copy;
3725 }
3726
3727 /* Figure out module layout, and allocate all the memory. */
3728 mod = layout_and_allocate(info, flags);
3729 if (IS_ERR(mod)) {
3730 err = PTR_ERR(mod);
3731 goto free_copy;
3732 }
3733
3734 audit_log_kern_module(mod->name);
3735
3736 /* Reserve our place in the list. */
3737 err = add_unformed_module(mod);
3738 if (err)
3739 goto free_module;
3740
3741#ifdef CONFIG_MODULE_SIG
3742 mod->sig_ok = info->sig_ok;
3743 if (!mod->sig_ok) {
3744 pr_notice_once("%s: module verification failed: signature "
3745 "and/or required key missing - tainting "
3746 "kernel\n", mod->name);
3747 add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK);
3748 }
3749#endif
3750
3751 /* To avoid stressing percpu allocator, do this once we're unique. */
3752 err = percpu_modalloc(mod, info);
3753 if (err)
3754 goto unlink_mod;
3755
3756 /* Now module is in final location, initialize linked lists, etc. */
3757 err = module_unload_init(mod);
3758 if (err)
3759 goto unlink_mod;
3760
3761 init_param_lock(mod);
3762
3763 /* Now we've got everything in the final locations, we can
3764 * find optional sections. */
3765 err = find_module_sections(mod, info);
3766 if (err)
3767 goto free_unload;
3768
3769 err = check_module_license_and_versions(mod);
3770 if (err)
3771 goto free_unload;
3772
3773 /* Set up MODINFO_ATTR fields */
3774 setup_modinfo(mod, info);
3775
3776 /* Fix up syms, so that st_value is a pointer to location. */
3777 err = simplify_symbols(mod, info);
3778 if (err < 0)
3779 goto free_modinfo;
3780
3781 err = apply_relocations(mod, info);
3782 if (err < 0)
3783 goto free_modinfo;
3784
3785 err = post_relocation(mod, info);
3786 if (err < 0)
3787 goto free_modinfo;
3788
3789 flush_module_icache(mod);
3790
3791 /* Now copy in args */
3792 mod->args = strndup_user(uargs, ~0UL >> 1);
3793 if (IS_ERR(mod->args)) {
3794 err = PTR_ERR(mod->args);
3795 goto free_arch_cleanup;
3796 }
3797
3798 dynamic_debug_setup(mod, info->debug, info->num_debug);
3799
3800 /* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
3801 ftrace_module_init(mod);
3802
3803 /* Finally it's fully formed, ready to start executing. */
3804 err = complete_formation(mod, info);
3805 if (err)
3806 goto ddebug_cleanup;
3807
3808 err = prepare_coming_module(mod);
3809 if (err)
3810 goto bug_cleanup;
3811
3812 /* Module is ready to execute: parsing args may do that. */
3813 after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
3814 -32768, 32767, mod,
3815 unknown_module_param_cb);
3816 if (IS_ERR(after_dashes)) {
3817 err = PTR_ERR(after_dashes);
3818 goto coming_cleanup;
3819 } else if (after_dashes) {
3820 pr_warn("%s: parameters '%s' after `--' ignored\n",
3821 mod->name, after_dashes);
3822 }
3823
3824 /* Link in to sysfs. */
3825 err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
3826 if (err < 0)
3827 goto coming_cleanup;
3828
3829 if (is_livepatch_module(mod)) {
3830 err = copy_module_elf(mod, info);
3831 if (err < 0)
3832 goto sysfs_cleanup;
3833 }
3834
3835 /* Get rid of temporary copy. */
3836 free_copy(info);
3837
3838 /* Done! */
3839 trace_module_load(mod);
3840
3841 return do_init_module(mod);
3842
3843 sysfs_cleanup:
3844 mod_sysfs_teardown(mod);
3845 coming_cleanup:
3846 mod->state = MODULE_STATE_GOING;
3847 destroy_params(mod->kp, mod->num_kp);
3848 blocking_notifier_call_chain(&module_notify_list,
3849 MODULE_STATE_GOING, mod);
3850 klp_module_going(mod);
3851 bug_cleanup:
3852 /* module_bug_cleanup needs module_mutex protection */
3853 mutex_lock(&module_mutex);
3854 module_bug_cleanup(mod);
3855 mutex_unlock(&module_mutex);
3856
3857 ddebug_cleanup:
3858 ftrace_release_mod(mod);
3859 dynamic_debug_remove(mod, info->debug);
3860 synchronize_rcu();
3861 kfree(mod->args);
3862 free_arch_cleanup:
3863 module_arch_cleanup(mod);
3864 free_modinfo:
3865 free_modinfo(mod);
3866 free_unload:
3867 module_unload_free(mod);
3868 unlink_mod:
3869 mutex_lock(&module_mutex);
3870 /* Unlink carefully: kallsyms could be walking list. */
3871 list_del_rcu(&mod->list);
3872 mod_tree_remove(mod);
3873 wake_up_all(&module_wq);
3874 /* Wait for RCU-sched synchronizing before releasing mod->list. */
3875 synchronize_rcu();
3876 mutex_unlock(&module_mutex);
3877 free_module:
3878 /* Free lock-classes; relies on the preceding sync_rcu() */
3879 lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
3880
3881 module_deallocate(mod, info);
3882 free_copy:
3883 free_copy(info);
3884 return err;
3885}
3886
3887SYSCALL_DEFINE3(init_module, void __user *, umod,
3888 unsigned long, len, const char __user *, uargs)
3889{
3890 int err;
3891 struct load_info info = { };
3892
3893 err = may_init_module();
3894 if (err)
3895 return err;
3896
3897 pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
3898 umod, len, uargs);
3899
3900 err = copy_module_from_user(umod, len, &info);
3901 if (err)
3902 return err;
3903
3904 return load_module(&info, uargs, 0);
3905}
3906
3907SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
3908{
3909 struct load_info info = { };
3910 loff_t size;
3911 void *hdr;
3912 int err;
3913
3914 err = may_init_module();
3915 if (err)
3916 return err;
3917
3918 pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags);
3919
3920 if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS
3921 |MODULE_INIT_IGNORE_VERMAGIC))
3922 return -EINVAL;
3923
3924 err = kernel_read_file_from_fd(fd, &hdr, &size, INT_MAX,
3925 READING_MODULE);
3926 if (err)
3927 return err;
3928 info.hdr = hdr;
3929 info.len = size;
3930
3931 return load_module(&info, uargs, flags);
3932}
3933
3934static inline int within(unsigned long addr, void *start, unsigned long size)
3935{
3936 return ((void *)addr >= start && (void *)addr < start + size);
3937}
3938
3939#ifdef CONFIG_KALLSYMS
3940/*
3941 * This ignores the intensely annoying "mapping symbols" found
3942 * in ARM ELF files: $a, $t and $d.
3943 */
3944static inline int is_arm_mapping_symbol(const char *str)
3945{
3946 if (str[0] == '.' && str[1] == 'L')
3947 return true;
3948 return str[0] == '$' && strchr("axtd", str[1])
3949 && (str[2] == '\0' || str[2] == '.');
3950}
3951
3952static const char *kallsyms_symbol_name(struct mod_kallsyms *kallsyms, unsigned int symnum)
3953{
3954 return kallsyms->strtab + kallsyms->symtab[symnum].st_name;
3955}
3956
3957/*
3958 * Given a module and address, find the corresponding symbol and return its name
3959 * while providing its size and offset if needed.
3960 */
3961static const char *find_kallsyms_symbol(struct module *mod,
3962 unsigned long addr,
3963 unsigned long *size,
3964 unsigned long *offset)
3965{
3966 unsigned int i, best = 0;
3967 unsigned long nextval, bestval;
3968 struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
3969
3970 /* At worse, next value is at end of module */
3971 if (within_module_init(addr, mod))
3972 nextval = (unsigned long)mod->init_layout.base+mod->init_layout.text_size;
3973 else
3974 nextval = (unsigned long)mod->core_layout.base+mod->core_layout.text_size;
3975
3976 bestval = kallsyms_symbol_value(&kallsyms->symtab[best]);
3977
3978 /* Scan for closest preceding symbol, and next symbol. (ELF
3979 starts real symbols at 1). */
3980 for (i = 1; i < kallsyms->num_symtab; i++) {
3981 const Elf_Sym *sym = &kallsyms->symtab[i];
3982 unsigned long thisval = kallsyms_symbol_value(sym);
3983
3984 if (sym->st_shndx == SHN_UNDEF)
3985 continue;
3986
3987 /* We ignore unnamed symbols: they're uninformative
3988 * and inserted at a whim. */
3989 if (*kallsyms_symbol_name(kallsyms, i) == '\0'
3990 || is_arm_mapping_symbol(kallsyms_symbol_name(kallsyms, i)))
3991 continue;
3992
3993 if (thisval <= addr && thisval > bestval) {
3994 best = i;
3995 bestval = thisval;
3996 }
3997 if (thisval > addr && thisval < nextval)
3998 nextval = thisval;
3999 }
4000
4001 if (!best)
4002 return NULL;
4003
4004 if (size)
4005 *size = nextval - bestval;
4006 if (offset)
4007 *offset = addr - bestval;
4008
4009 return kallsyms_symbol_name(kallsyms, best);
4010}
4011
4012void * __weak dereference_module_function_descriptor(struct module *mod,
4013 void *ptr)
4014{
4015 return ptr;
4016}
4017
4018/* For kallsyms to ask for address resolution. NULL means not found. Careful
4019 * not to lock to avoid deadlock on oopses, simply disable preemption. */
4020const char *module_address_lookup(unsigned long addr,
4021 unsigned long *size,
4022 unsigned long *offset,
4023 char **modname,
4024 char *namebuf)
4025{
4026 const char *ret = NULL;
4027 struct module *mod;
4028
4029 preempt_disable();
4030 mod = __module_address(addr);
4031 if (mod) {
4032 if (modname)
4033 *modname = mod->name;
4034
4035 ret = find_kallsyms_symbol(mod, addr, size, offset);
4036 }
4037 /* Make a copy in here where it's safe */
4038 if (ret) {
4039 strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
4040 ret = namebuf;
4041 }
4042 preempt_enable();
4043
4044 return ret;
4045}
4046
4047int lookup_module_symbol_name(unsigned long addr, char *symname)
4048{
4049 struct module *mod;
4050
4051 preempt_disable();
4052 list_for_each_entry_rcu(mod, &modules, list) {
4053 if (mod->state == MODULE_STATE_UNFORMED)
4054 continue;
4055 if (within_module(addr, mod)) {
4056 const char *sym;
4057
4058 sym = find_kallsyms_symbol(mod, addr, NULL, NULL);
4059 if (!sym)
4060 goto out;
4061
4062 strlcpy(symname, sym, KSYM_NAME_LEN);
4063 preempt_enable();
4064 return 0;
4065 }
4066 }
4067out:
4068 preempt_enable();
4069 return -ERANGE;
4070}
4071
4072int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
4073 unsigned long *offset, char *modname, char *name)
4074{
4075 struct module *mod;
4076
4077 preempt_disable();
4078 list_for_each_entry_rcu(mod, &modules, list) {
4079 if (mod->state == MODULE_STATE_UNFORMED)
4080 continue;
4081 if (within_module(addr, mod)) {
4082 const char *sym;
4083
4084 sym = find_kallsyms_symbol(mod, addr, size, offset);
4085 if (!sym)
4086 goto out;
4087 if (modname)
4088 strlcpy(modname, mod->name, MODULE_NAME_LEN);
4089 if (name)
4090 strlcpy(name, sym, KSYM_NAME_LEN);
4091 preempt_enable();
4092 return 0;
4093 }
4094 }
4095out:
4096 preempt_enable();
4097 return -ERANGE;
4098}
4099
4100int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
4101 char *name, char *module_name, int *exported)
4102{
4103 struct module *mod;
4104
4105 preempt_disable();
4106 list_for_each_entry_rcu(mod, &modules, list) {
4107 struct mod_kallsyms *kallsyms;
4108
4109 if (mod->state == MODULE_STATE_UNFORMED)
4110 continue;
4111 kallsyms = rcu_dereference_sched(mod->kallsyms);
4112 if (symnum < kallsyms->num_symtab) {
4113 const Elf_Sym *sym = &kallsyms->symtab[symnum];
4114
4115 *value = kallsyms_symbol_value(sym);
4116 *type = kallsyms->typetab[symnum];
4117 strlcpy(name, kallsyms_symbol_name(kallsyms, symnum), KSYM_NAME_LEN);
4118 strlcpy(module_name, mod->name, MODULE_NAME_LEN);
4119 *exported = is_exported(name, *value, mod);
4120 preempt_enable();
4121 return 0;
4122 }
4123 symnum -= kallsyms->num_symtab;
4124 }
4125 preempt_enable();
4126 return -ERANGE;
4127}
4128
4129/* Given a module and name of symbol, find and return the symbol's value */
4130static unsigned long find_kallsyms_symbol_value(struct module *mod, const char *name)
4131{
4132 unsigned int i;
4133 struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
4134
4135 for (i = 0; i < kallsyms->num_symtab; i++) {
4136 const Elf_Sym *sym = &kallsyms->symtab[i];
4137
4138 if (strcmp(name, kallsyms_symbol_name(kallsyms, i)) == 0 &&
4139 sym->st_shndx != SHN_UNDEF)
4140 return kallsyms_symbol_value(sym);
4141 }
4142 return 0;
4143}
4144
4145/* Look for this name: can be of form module:name. */
4146unsigned long module_kallsyms_lookup_name(const char *name)
4147{
4148 struct module *mod;
4149 char *colon;
4150 unsigned long ret = 0;
4151
4152 /* Don't lock: we're in enough trouble already. */
4153 preempt_disable();
4154 if ((colon = strnchr(name, MODULE_NAME_LEN, ':')) != NULL) {
4155 if ((mod = find_module_all(name, colon - name, false)) != NULL)
4156 ret = find_kallsyms_symbol_value(mod, colon+1);
4157 } else {
4158 list_for_each_entry_rcu(mod, &modules, list) {
4159 if (mod->state == MODULE_STATE_UNFORMED)
4160 continue;
4161 if ((ret = find_kallsyms_symbol_value(mod, name)) != 0)
4162 break;
4163 }
4164 }
4165 preempt_enable();
4166 return ret;
4167}
4168
4169int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
4170 struct module *, unsigned long),
4171 void *data)
4172{
4173 struct module *mod;
4174 unsigned int i;
4175 int ret;
4176
4177 module_assert_mutex();
4178
4179 list_for_each_entry(mod, &modules, list) {
4180 /* We hold module_mutex: no need for rcu_dereference_sched */
4181 struct mod_kallsyms *kallsyms = mod->kallsyms;
4182
4183 if (mod->state == MODULE_STATE_UNFORMED)
4184 continue;
4185 for (i = 0; i < kallsyms->num_symtab; i++) {
4186 const Elf_Sym *sym = &kallsyms->symtab[i];
4187
4188 if (sym->st_shndx == SHN_UNDEF)
4189 continue;
4190
4191 ret = fn(data, kallsyms_symbol_name(kallsyms, i),
4192 mod, kallsyms_symbol_value(sym));
4193 if (ret != 0)
4194 return ret;
4195 }
4196 }
4197 return 0;
4198}
4199#endif /* CONFIG_KALLSYMS */
4200
4201/* Maximum number of characters written by module_flags() */
4202#define MODULE_FLAGS_BUF_SIZE (TAINT_FLAGS_COUNT + 4)
4203
4204/* Keep in sync with MODULE_FLAGS_BUF_SIZE !!! */
4205static char *module_flags(struct module *mod, char *buf)
4206{
4207 int bx = 0;
4208
4209 BUG_ON(mod->state == MODULE_STATE_UNFORMED);
4210 if (mod->taints ||
4211 mod->state == MODULE_STATE_GOING ||
4212 mod->state == MODULE_STATE_COMING) {
4213 buf[bx++] = '(';
4214 bx += module_flags_taint(mod, buf + bx);
4215 /* Show a - for module-is-being-unloaded */
4216 if (mod->state == MODULE_STATE_GOING)
4217 buf[bx++] = '-';
4218 /* Show a + for module-is-being-loaded */
4219 if (mod->state == MODULE_STATE_COMING)
4220 buf[bx++] = '+';
4221 buf[bx++] = ')';
4222 }
4223 buf[bx] = '\0';
4224
4225 return buf;
4226}
4227
4228#ifdef CONFIG_PROC_FS
4229/* Called by the /proc file system to return a list of modules. */
4230static void *m_start(struct seq_file *m, loff_t *pos)
4231{
4232 mutex_lock(&module_mutex);
4233 return seq_list_start(&modules, *pos);
4234}
4235
4236static void *m_next(struct seq_file *m, void *p, loff_t *pos)
4237{
4238 return seq_list_next(p, &modules, pos);
4239}
4240
4241static void m_stop(struct seq_file *m, void *p)
4242{
4243 mutex_unlock(&module_mutex);
4244}
4245
4246static int m_show(struct seq_file *m, void *p)
4247{
4248 struct module *mod = list_entry(p, struct module, list);
4249 char buf[MODULE_FLAGS_BUF_SIZE];
4250 void *value;
4251
4252 /* We always ignore unformed modules. */
4253 if (mod->state == MODULE_STATE_UNFORMED)
4254 return 0;
4255
4256 seq_printf(m, "%s %u",
4257 mod->name, mod->init_layout.size + mod->core_layout.size);
4258 print_unload_info(m, mod);
4259
4260 /* Informative for users. */
4261 seq_printf(m, " %s",
4262 mod->state == MODULE_STATE_GOING ? "Unloading" :
4263 mod->state == MODULE_STATE_COMING ? "Loading" :
4264 "Live");
4265 /* Used by oprofile and other similar tools. */
4266 value = m->private ? NULL : mod->core_layout.base;
4267 seq_printf(m, " 0x%px", value);
4268
4269 /* Taints info */
4270 if (mod->taints)
4271 seq_printf(m, " %s", module_flags(mod, buf));
4272
4273 seq_puts(m, "\n");
4274 return 0;
4275}
4276
4277/* Format: modulename size refcount deps address
4278
4279 Where refcount is a number or -, and deps is a comma-separated list
4280 of depends or -.
4281*/
4282static const struct seq_operations modules_op = {
4283 .start = m_start,
4284 .next = m_next,
4285 .stop = m_stop,
4286 .show = m_show
4287};
4288
4289/*
4290 * This also sets the "private" pointer to non-NULL if the
4291 * kernel pointers should be hidden (so you can just test
4292 * "m->private" to see if you should keep the values private).
4293 *
4294 * We use the same logic as for /proc/kallsyms.
4295 */
4296static int modules_open(struct inode *inode, struct file *file)
4297{
4298 int err = seq_open(file, &modules_op);
4299
4300 if (!err) {
4301 struct seq_file *m = file->private_data;
4302 m->private = kallsyms_show_value() ? NULL : (void *)8ul;
4303 }
4304
4305 return err;
4306}
4307
4308static const struct file_operations proc_modules_operations = {
4309 .open = modules_open,
4310 .read = seq_read,
4311 .llseek = seq_lseek,
4312 .release = seq_release,
4313};
4314
4315static int __init proc_modules_init(void)
4316{
4317 proc_create("modules", 0, NULL, &proc_modules_operations);
4318 return 0;
4319}
4320module_init(proc_modules_init);
4321#endif
4322
4323/* Given an address, look for it in the module exception tables. */
4324const struct exception_table_entry *search_module_extables(unsigned long addr)
4325{
4326 const struct exception_table_entry *e = NULL;
4327 struct module *mod;
4328
4329 preempt_disable();
4330 mod = __module_address(addr);
4331 if (!mod)
4332 goto out;
4333
4334 if (!mod->num_exentries)
4335 goto out;
4336
4337 e = search_extable(mod->extable,
4338 mod->num_exentries,
4339 addr);
4340out:
4341 preempt_enable();
4342
4343 /*
4344 * Now, if we found one, we are running inside it now, hence
4345 * we cannot unload the module, hence no refcnt needed.
4346 */
4347 return e;
4348}
4349
4350/*
4351 * is_module_address - is this address inside a module?
4352 * @addr: the address to check.
4353 *
4354 * See is_module_text_address() if you simply want to see if the address
4355 * is code (not data).
4356 */
4357bool is_module_address(unsigned long addr)
4358{
4359 bool ret;
4360
4361 preempt_disable();
4362 ret = __module_address(addr) != NULL;
4363 preempt_enable();
4364
4365 return ret;
4366}
4367
4368/*
4369 * __module_address - get the module which contains an address.
4370 * @addr: the address.
4371 *
4372 * Must be called with preempt disabled or module mutex held so that
4373 * module doesn't get freed during this.
4374 */
4375struct module *__module_address(unsigned long addr)
4376{
4377 struct module *mod;
4378
4379 if (addr < module_addr_min || addr > module_addr_max)
4380 return NULL;
4381
4382 module_assert_mutex_or_preempt();
4383
4384 mod = mod_find(addr);
4385 if (mod) {
4386 BUG_ON(!within_module(addr, mod));
4387 if (mod->state == MODULE_STATE_UNFORMED)
4388 mod = NULL;
4389 }
4390 return mod;
4391}
4392EXPORT_SYMBOL_GPL(__module_address);
4393
4394/*
4395 * is_module_text_address - is this address inside module code?
4396 * @addr: the address to check.
4397 *
4398 * See is_module_address() if you simply want to see if the address is
4399 * anywhere in a module. See kernel_text_address() for testing if an
4400 * address corresponds to kernel or module code.
4401 */
4402bool is_module_text_address(unsigned long addr)
4403{
4404 bool ret;
4405
4406 preempt_disable();
4407 ret = __module_text_address(addr) != NULL;
4408 preempt_enable();
4409
4410 return ret;
4411}
4412
4413/*
4414 * __module_text_address - get the module whose code contains an address.
4415 * @addr: the address.
4416 *
4417 * Must be called with preempt disabled or module mutex held so that
4418 * module doesn't get freed during this.
4419 */
4420struct module *__module_text_address(unsigned long addr)
4421{
4422 struct module *mod = __module_address(addr);
4423 if (mod) {
4424 /* Make sure it's within the text section. */
4425 if (!within(addr, mod->init_layout.base, mod->init_layout.text_size)
4426 && !within(addr, mod->core_layout.base, mod->core_layout.text_size))
4427 mod = NULL;
4428 }
4429 return mod;
4430}
4431EXPORT_SYMBOL_GPL(__module_text_address);
4432
4433/* Don't grab lock, we're oopsing. */
4434void print_modules(void)
4435{
4436 struct module *mod;
4437 char buf[MODULE_FLAGS_BUF_SIZE];
4438
4439 printk(KERN_DEFAULT "Modules linked in:");
4440 /* Most callers should already have preempt disabled, but make sure */
4441 preempt_disable();
4442 list_for_each_entry_rcu(mod, &modules, list) {
4443 if (mod->state == MODULE_STATE_UNFORMED)
4444 continue;
4445 pr_cont(" %s%s", mod->name, module_flags(mod, buf));
4446 }
4447 preempt_enable();
4448 if (last_unloaded_module[0])
4449 pr_cont(" [last unloaded: %s]", last_unloaded_module);
4450 pr_cont("\n");
4451}
4452
4453#ifdef CONFIG_MODVERSIONS
4454/* Generate the signature for all relevant module structures here.
4455 * If these change, we don't want to try to parse the module. */
4456void module_layout(struct module *mod,
4457 struct modversion_info *ver,
4458 struct kernel_param *kp,
4459 struct kernel_symbol *ks,
4460 struct tracepoint * const *tp)
4461{
4462}
4463EXPORT_SYMBOL(module_layout);
4464#endif