projects/linux·blob v3.3-rc4 · refs

3507 lines · 89.2 KiB

1/*
2 Copyright (C) 2002 Richard Henderson
3 Copyright (C) 2001 Rusty Russell, 2002, 2010 Rusty Russell IBM.
4
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 2 of the License, or
8 (at your option) any later version.
9
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
14
15 You should have received a copy of the GNU General Public License
16 along with this program; if not, write to the Free Software
17 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18*/
19#include <linux/export.h>
20#include <linux/moduleloader.h>
21#include <linux/ftrace_event.h>
22#include <linux/init.h>
23#include <linux/kallsyms.h>
24#include <linux/fs.h>
25#include <linux/sysfs.h>
26#include <linux/kernel.h>
27#include <linux/slab.h>
28#include <linux/vmalloc.h>
29#include <linux/elf.h>
30#include <linux/proc_fs.h>
31#include <linux/seq_file.h>
32#include <linux/syscalls.h>
33#include <linux/fcntl.h>
34#include <linux/rcupdate.h>
35#include <linux/capability.h>
36#include <linux/cpu.h>
37#include <linux/moduleparam.h>
38#include <linux/errno.h>
39#include <linux/err.h>
40#include <linux/vermagic.h>
41#include <linux/notifier.h>
42#include <linux/sched.h>
43#include <linux/stop_machine.h>
44#include <linux/device.h>
45#include <linux/string.h>
46#include <linux/mutex.h>
47#include <linux/rculist.h>
48#include <asm/uaccess.h>
49#include <asm/cacheflush.h>
50#include <asm/mmu_context.h>
51#include <linux/license.h>
52#include <asm/sections.h>
53#include <linux/tracepoint.h>
54#include <linux/ftrace.h>
55#include <linux/async.h>
56#include <linux/percpu.h>
57#include <linux/kmemleak.h>
58#include <linux/jump_label.h>
59#include <linux/pfn.h>
60#include <linux/bsearch.h>
61
62#define CREATE_TRACE_POINTS
63#include <trace/events/module.h>
64
65#ifndef ARCH_SHF_SMALL
66#define ARCH_SHF_SMALL 0
67#endif
68
69/*
70 * Modules' sections will be aligned on page boundaries
71 * to ensure complete separation of code and data, but
72 * only when CONFIG_DEBUG_SET_MODULE_RONX=y
73 */
74#ifdef CONFIG_DEBUG_SET_MODULE_RONX
75# define debug_align(X) ALIGN(X, PAGE_SIZE)
76#else
77# define debug_align(X) (X)
78#endif
79
80/*
81 * Given BASE and SIZE this macro calculates the number of pages the
82 * memory regions occupies
83 */
84#define MOD_NUMBER_OF_PAGES(BASE, SIZE) (((SIZE) > 0) ? \
85 (PFN_DOWN((unsigned long)(BASE) + (SIZE) - 1) - \
86 PFN_DOWN((unsigned long)BASE) + 1) \
87 : (0UL))
88
89/* If this is set, the section belongs in the init part of the module */
90#define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
91
92/*
93 * Mutex protects:
94 * 1) List of modules (also safely readable with preempt_disable),
95 * 2) module_use links,
96 * 3) module_addr_min/module_addr_max.
97 * (delete uses stop_machine/add uses RCU list operations). */
98DEFINE_MUTEX(module_mutex);
99EXPORT_SYMBOL_GPL(module_mutex);
100static LIST_HEAD(modules);
101#ifdef CONFIG_KGDB_KDB
102struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
103#endif /* CONFIG_KGDB_KDB */
104
105
106/* Block module loading/unloading? */
107int modules_disabled = 0;
108
109/* Waiting for a module to finish initializing? */
110static DECLARE_WAIT_QUEUE_HEAD(module_wq);
111
112static BLOCKING_NOTIFIER_HEAD(module_notify_list);
113
114/* Bounds of module allocation, for speeding __module_address.
115 * Protected by module_mutex. */
116static unsigned long module_addr_min = -1UL, module_addr_max = 0;
117
118int register_module_notifier(struct notifier_block * nb)
119{
120 return blocking_notifier_chain_register(&module_notify_list, nb);
121}
122EXPORT_SYMBOL(register_module_notifier);
123
124int unregister_module_notifier(struct notifier_block * nb)
125{
126 return blocking_notifier_chain_unregister(&module_notify_list, nb);
127}
128EXPORT_SYMBOL(unregister_module_notifier);
129
130struct load_info {
131 Elf_Ehdr *hdr;
132 unsigned long len;
133 Elf_Shdr *sechdrs;
134 char *secstrings, *strtab;
135 unsigned long symoffs, stroffs;
136 struct _ddebug *debug;
137 unsigned int num_debug;
138 struct {
139 unsigned int sym, str, mod, vers, info, pcpu;
140 } index;
141};
142
143/* We require a truly strong try_module_get(): 0 means failure due to
144 ongoing or failed initialization etc. */
145static inline int strong_try_module_get(struct module *mod)
146{
147 if (mod && mod->state == MODULE_STATE_COMING)
148 return -EBUSY;
149 if (try_module_get(mod))
150 return 0;
151 else
152 return -ENOENT;
153}
154
155static inline void add_taint_module(struct module *mod, unsigned flag)
156{
157 add_taint(flag);
158 mod->taints |= (1U << flag);
159}
160
161/*
162 * A thread that wants to hold a reference to a module only while it
163 * is running can call this to safely exit. nfsd and lockd use this.
164 */
165void __module_put_and_exit(struct module *mod, long code)
166{
167 module_put(mod);
168 do_exit(code);
169}
170EXPORT_SYMBOL(__module_put_and_exit);
171
172/* Find a module section: 0 means not found. */
173static unsigned int find_sec(const struct load_info *info, const char *name)
174{
175 unsigned int i;
176
177 for (i = 1; i < info->hdr->e_shnum; i++) {
178 Elf_Shdr *shdr = &info->sechdrs[i];
179 /* Alloc bit cleared means "ignore it." */
180 if ((shdr->sh_flags & SHF_ALLOC)
181 && strcmp(info->secstrings + shdr->sh_name, name) == 0)
182 return i;
183 }
184 return 0;
185}
186
187/* Find a module section, or NULL. */
188static void *section_addr(const struct load_info *info, const char *name)
189{
190 /* Section 0 has sh_addr 0. */
191 return (void *)info->sechdrs[find_sec(info, name)].sh_addr;
192}
193
194/* Find a module section, or NULL. Fill in number of "objects" in section. */
195static void *section_objs(const struct load_info *info,
196 const char *name,
197 size_t object_size,
198 unsigned int *num)
199{
200 unsigned int sec = find_sec(info, name);
201
202 /* Section 0 has sh_addr 0 and sh_size 0. */
203 *num = info->sechdrs[sec].sh_size / object_size;
204 return (void *)info->sechdrs[sec].sh_addr;
205}
206
207/* Provided by the linker */
208extern const struct kernel_symbol __start___ksymtab[];
209extern const struct kernel_symbol __stop___ksymtab[];
210extern const struct kernel_symbol __start___ksymtab_gpl[];
211extern const struct kernel_symbol __stop___ksymtab_gpl[];
212extern const struct kernel_symbol __start___ksymtab_gpl_future[];
213extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
214extern const unsigned long __start___kcrctab[];
215extern const unsigned long __start___kcrctab_gpl[];
216extern const unsigned long __start___kcrctab_gpl_future[];
217#ifdef CONFIG_UNUSED_SYMBOLS
218extern const struct kernel_symbol __start___ksymtab_unused[];
219extern const struct kernel_symbol __stop___ksymtab_unused[];
220extern const struct kernel_symbol __start___ksymtab_unused_gpl[];
221extern const struct kernel_symbol __stop___ksymtab_unused_gpl[];
222extern const unsigned long __start___kcrctab_unused[];
223extern const unsigned long __start___kcrctab_unused_gpl[];
224#endif
225
226#ifndef CONFIG_MODVERSIONS
227#define symversion(base, idx) NULL
228#else
229#define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
230#endif
231
232static bool each_symbol_in_section(const struct symsearch *arr,
233 unsigned int arrsize,
234 struct module *owner,
235 bool (*fn)(const struct symsearch *syms,
236 struct module *owner,
237 void *data),
238 void *data)
239{
240 unsigned int j;
241
242 for (j = 0; j < arrsize; j++) {
243 if (fn(&arr[j], owner, data))
244 return true;
245 }
246
247 return false;
248}
249
250/* Returns true as soon as fn returns true, otherwise false. */
251bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
252 struct module *owner,
253 void *data),
254 void *data)
255{
256 struct module *mod;
257 static const struct symsearch arr[] = {
258 { __start___ksymtab, __stop___ksymtab, __start___kcrctab,
259 NOT_GPL_ONLY, false },
260 { __start___ksymtab_gpl, __stop___ksymtab_gpl,
261 __start___kcrctab_gpl,
262 GPL_ONLY, false },
263 { __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future,
264 __start___kcrctab_gpl_future,
265 WILL_BE_GPL_ONLY, false },
266#ifdef CONFIG_UNUSED_SYMBOLS
267 { __start___ksymtab_unused, __stop___ksymtab_unused,
268 __start___kcrctab_unused,
269 NOT_GPL_ONLY, true },
270 { __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl,
271 __start___kcrctab_unused_gpl,
272 GPL_ONLY, true },
273#endif
274 };
275
276 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data))
277 return true;
278
279 list_for_each_entry_rcu(mod, &modules, list) {
280 struct symsearch arr[] = {
281 { mod->syms, mod->syms + mod->num_syms, mod->crcs,
282 NOT_GPL_ONLY, false },
283 { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
284 mod->gpl_crcs,
285 GPL_ONLY, false },
286 { mod->gpl_future_syms,
287 mod->gpl_future_syms + mod->num_gpl_future_syms,
288 mod->gpl_future_crcs,
289 WILL_BE_GPL_ONLY, false },
290#ifdef CONFIG_UNUSED_SYMBOLS
291 { mod->unused_syms,
292 mod->unused_syms + mod->num_unused_syms,
293 mod->unused_crcs,
294 NOT_GPL_ONLY, true },
295 { mod->unused_gpl_syms,
296 mod->unused_gpl_syms + mod->num_unused_gpl_syms,
297 mod->unused_gpl_crcs,
298 GPL_ONLY, true },
299#endif
300 };
301
302 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data))
303 return true;
304 }
305 return false;
306}
307EXPORT_SYMBOL_GPL(each_symbol_section);
308
309struct find_symbol_arg {
310 /* Input */
311 const char *name;
312 bool gplok;
313 bool warn;
314
315 /* Output */
316 struct module *owner;
317 const unsigned long *crc;
318 const struct kernel_symbol *sym;
319};
320
321static bool check_symbol(const struct symsearch *syms,
322 struct module *owner,
323 unsigned int symnum, void *data)
324{
325 struct find_symbol_arg *fsa = data;
326
327 if (!fsa->gplok) {
328 if (syms->licence == GPL_ONLY)
329 return false;
330 if (syms->licence == WILL_BE_GPL_ONLY && fsa->warn) {
331 printk(KERN_WARNING "Symbol %s is being used "
332 "by a non-GPL module, which will not "
333 "be allowed in the future\n", fsa->name);
334 printk(KERN_WARNING "Please see the file "
335 "Documentation/feature-removal-schedule.txt "
336 "in the kernel source tree for more details.\n");
337 }
338 }
339
340#ifdef CONFIG_UNUSED_SYMBOLS
341 if (syms->unused && fsa->warn) {
342 printk(KERN_WARNING "Symbol %s is marked as UNUSED, "
343 "however this module is using it.\n", fsa->name);
344 printk(KERN_WARNING
345 "This symbol will go away in the future.\n");
346 printk(KERN_WARNING
347 "Please evalute if this is the right api to use and if "
348 "it really is, submit a report the linux kernel "
349 "mailinglist together with submitting your code for "
350 "inclusion.\n");
351 }
352#endif
353
354 fsa->owner = owner;
355 fsa->crc = symversion(syms->crcs, symnum);
356 fsa->sym = &syms->start[symnum];
357 return true;
358}
359
360static int cmp_name(const void *va, const void *vb)
361{
362 const char *a;
363 const struct kernel_symbol *b;
364 a = va; b = vb;
365 return strcmp(a, b->name);
366}
367
368static bool find_symbol_in_section(const struct symsearch *syms,
369 struct module *owner,
370 void *data)
371{
372 struct find_symbol_arg *fsa = data;
373 struct kernel_symbol *sym;
374
375 sym = bsearch(fsa->name, syms->start, syms->stop - syms->start,
376 sizeof(struct kernel_symbol), cmp_name);
377
378 if (sym != NULL && check_symbol(syms, owner, sym - syms->start, data))
379 return true;
380
381 return false;
382}
383
384/* Find a symbol and return it, along with, (optional) crc and
385 * (optional) module which owns it. Needs preempt disabled or module_mutex. */
386const struct kernel_symbol *find_symbol(const char *name,
387 struct module **owner,
388 const unsigned long **crc,
389 bool gplok,
390 bool warn)
391{
392 struct find_symbol_arg fsa;
393
394 fsa.name = name;
395 fsa.gplok = gplok;
396 fsa.warn = warn;
397
398 if (each_symbol_section(find_symbol_in_section, &fsa)) {
399 if (owner)
400 *owner = fsa.owner;
401 if (crc)
402 *crc = fsa.crc;
403 return fsa.sym;
404 }
405
406 pr_debug("Failed to find symbol %s\n", name);
407 return NULL;
408}
409EXPORT_SYMBOL_GPL(find_symbol);
410
411/* Search for module by name: must hold module_mutex. */
412struct module *find_module(const char *name)
413{
414 struct module *mod;
415
416 list_for_each_entry(mod, &modules, list) {
417 if (strcmp(mod->name, name) == 0)
418 return mod;
419 }
420 return NULL;
421}
422EXPORT_SYMBOL_GPL(find_module);
423
424#ifdef CONFIG_SMP
425
426static inline void __percpu *mod_percpu(struct module *mod)
427{
428 return mod->percpu;
429}
430
431static int percpu_modalloc(struct module *mod,
432 unsigned long size, unsigned long align)
433{
434 if (align > PAGE_SIZE) {
435 printk(KERN_WARNING "%s: per-cpu alignment %li > %li\n",
436 mod->name, align, PAGE_SIZE);
437 align = PAGE_SIZE;
438 }
439
440 mod->percpu = __alloc_reserved_percpu(size, align);
441 if (!mod->percpu) {
442 printk(KERN_WARNING
443 "%s: Could not allocate %lu bytes percpu data\n",
444 mod->name, size);
445 return -ENOMEM;
446 }
447 mod->percpu_size = size;
448 return 0;
449}
450
451static void percpu_modfree(struct module *mod)
452{
453 free_percpu(mod->percpu);
454}
455
456static unsigned int find_pcpusec(struct load_info *info)
457{
458 return find_sec(info, ".data..percpu");
459}
460
461static void percpu_modcopy(struct module *mod,
462 const void *from, unsigned long size)
463{
464 int cpu;
465
466 for_each_possible_cpu(cpu)
467 memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
468}
469
470/**
471 * is_module_percpu_address - test whether address is from module static percpu
472 * @addr: address to test
473 *
474 * Test whether @addr belongs to module static percpu area.
475 *
476 * RETURNS:
477 * %true if @addr is from module static percpu area
478 */
479bool is_module_percpu_address(unsigned long addr)
480{
481 struct module *mod;
482 unsigned int cpu;
483
484 preempt_disable();
485
486 list_for_each_entry_rcu(mod, &modules, list) {
487 if (!mod->percpu_size)
488 continue;
489 for_each_possible_cpu(cpu) {
490 void *start = per_cpu_ptr(mod->percpu, cpu);
491
492 if ((void *)addr >= start &&
493 (void *)addr < start + mod->percpu_size) {
494 preempt_enable();
495 return true;
496 }
497 }
498 }
499
500 preempt_enable();
501 return false;
502}
503
504#else /* ... !CONFIG_SMP */
505
506static inline void __percpu *mod_percpu(struct module *mod)
507{
508 return NULL;
509}
510static inline int percpu_modalloc(struct module *mod,
511 unsigned long size, unsigned long align)
512{
513 return -ENOMEM;
514}
515static inline void percpu_modfree(struct module *mod)
516{
517}
518static unsigned int find_pcpusec(struct load_info *info)
519{
520 return 0;
521}
522static inline void percpu_modcopy(struct module *mod,
523 const void *from, unsigned long size)
524{
525 /* pcpusec should be 0, and size of that section should be 0. */
526 BUG_ON(size != 0);
527}
528bool is_module_percpu_address(unsigned long addr)
529{
530 return false;
531}
532
533#endif /* CONFIG_SMP */
534
535#define MODINFO_ATTR(field) \
536static void setup_modinfo_##field(struct module *mod, const char *s) \
537{ \
538 mod->field = kstrdup(s, GFP_KERNEL); \
539} \
540static ssize_t show_modinfo_##field(struct module_attribute *mattr, \
541 struct module_kobject *mk, char *buffer) \
542{ \
543 return sprintf(buffer, "%s\n", mk->mod->field); \
544} \
545static int modinfo_##field##_exists(struct module *mod) \
546{ \
547 return mod->field != NULL; \
548} \
549static void free_modinfo_##field(struct module *mod) \
550{ \
551 kfree(mod->field); \
552 mod->field = NULL; \
553} \
554static struct module_attribute modinfo_##field = { \
555 .attr = { .name = __stringify(field), .mode = 0444 }, \
556 .show = show_modinfo_##field, \
557 .setup = setup_modinfo_##field, \
558 .test = modinfo_##field##_exists, \
559 .free = free_modinfo_##field, \
560};
561
562MODINFO_ATTR(version);
563MODINFO_ATTR(srcversion);
564
565static char last_unloaded_module[MODULE_NAME_LEN+1];
566
567#ifdef CONFIG_MODULE_UNLOAD
568
569EXPORT_TRACEPOINT_SYMBOL(module_get);
570
571/* Init the unload section of the module. */
572static int module_unload_init(struct module *mod)
573{
574 mod->refptr = alloc_percpu(struct module_ref);
575 if (!mod->refptr)
576 return -ENOMEM;
577
578 INIT_LIST_HEAD(&mod->source_list);
579 INIT_LIST_HEAD(&mod->target_list);
580
581 /* Hold reference count during initialization. */
582 __this_cpu_write(mod->refptr->incs, 1);
583 /* Backwards compatibility macros put refcount during init. */
584 mod->waiter = current;
585
586 return 0;
587}
588
589/* Does a already use b? */
590static int already_uses(struct module *a, struct module *b)
591{
592 struct module_use *use;
593
594 list_for_each_entry(use, &b->source_list, source_list) {
595 if (use->source == a) {
596 pr_debug("%s uses %s!\n", a->name, b->name);
597 return 1;
598 }
599 }
600 pr_debug("%s does not use %s!\n", a->name, b->name);
601 return 0;
602}
603
604/*
605 * Module a uses b
606 * - we add 'a' as a "source", 'b' as a "target" of module use
607 * - the module_use is added to the list of 'b' sources (so
608 * 'b' can walk the list to see who sourced them), and of 'a'
609 * targets (so 'a' can see what modules it targets).
610 */
611static int add_module_usage(struct module *a, struct module *b)
612{
613 struct module_use *use;
614
615 pr_debug("Allocating new usage for %s.\n", a->name);
616 use = kmalloc(sizeof(*use), GFP_ATOMIC);
617 if (!use) {
618 printk(KERN_WARNING "%s: out of memory loading\n", a->name);
619 return -ENOMEM;
620 }
621
622 use->source = a;
623 use->target = b;
624 list_add(&use->source_list, &b->source_list);
625 list_add(&use->target_list, &a->target_list);
626 return 0;
627}
628
629/* Module a uses b: caller needs module_mutex() */
630int ref_module(struct module *a, struct module *b)
631{
632 int err;
633
634 if (b == NULL || already_uses(a, b))
635 return 0;
636
637 /* If module isn't available, we fail. */
638 err = strong_try_module_get(b);
639 if (err)
640 return err;
641
642 err = add_module_usage(a, b);
643 if (err) {
644 module_put(b);
645 return err;
646 }
647 return 0;
648}
649EXPORT_SYMBOL_GPL(ref_module);
650
651/* Clear the unload stuff of the module. */
652static void module_unload_free(struct module *mod)
653{
654 struct module_use *use, *tmp;
655
656 mutex_lock(&module_mutex);
657 list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
658 struct module *i = use->target;
659 pr_debug("%s unusing %s\n", mod->name, i->name);
660 module_put(i);
661 list_del(&use->source_list);
662 list_del(&use->target_list);
663 kfree(use);
664 }
665 mutex_unlock(&module_mutex);
666
667 free_percpu(mod->refptr);
668}
669
670#ifdef CONFIG_MODULE_FORCE_UNLOAD
671static inline int try_force_unload(unsigned int flags)
672{
673 int ret = (flags & O_TRUNC);
674 if (ret)
675 add_taint(TAINT_FORCED_RMMOD);
676 return ret;
677}
678#else
679static inline int try_force_unload(unsigned int flags)
680{
681 return 0;
682}
683#endif /* CONFIG_MODULE_FORCE_UNLOAD */
684
685struct stopref
686{
687 struct module *mod;
688 int flags;
689 int *forced;
690};
691
692/* Whole machine is stopped with interrupts off when this runs. */
693static int __try_stop_module(void *_sref)
694{
695 struct stopref *sref = _sref;
696
697 /* If it's not unused, quit unless we're forcing. */
698 if (module_refcount(sref->mod) != 0) {
699 if (!(*sref->forced = try_force_unload(sref->flags)))
700 return -EWOULDBLOCK;
701 }
702
703 /* Mark it as dying. */
704 sref->mod->state = MODULE_STATE_GOING;
705 return 0;
706}
707
708static int try_stop_module(struct module *mod, int flags, int *forced)
709{
710 if (flags & O_NONBLOCK) {
711 struct stopref sref = { mod, flags, forced };
712
713 return stop_machine(__try_stop_module, &sref, NULL);
714 } else {
715 /* We don't need to stop the machine for this. */
716 mod->state = MODULE_STATE_GOING;
717 synchronize_sched();
718 return 0;
719 }
720}
721
722unsigned long module_refcount(struct module *mod)
723{
724 unsigned long incs = 0, decs = 0;
725 int cpu;
726
727 for_each_possible_cpu(cpu)
728 decs += per_cpu_ptr(mod->refptr, cpu)->decs;
729 /*
730 * ensure the incs are added up after the decs.
731 * module_put ensures incs are visible before decs with smp_wmb.
732 *
733 * This 2-count scheme avoids the situation where the refcount
734 * for CPU0 is read, then CPU0 increments the module refcount,
735 * then CPU1 drops that refcount, then the refcount for CPU1 is
736 * read. We would record a decrement but not its corresponding
737 * increment so we would see a low count (disaster).
738 *
739 * Rare situation? But module_refcount can be preempted, and we
740 * might be tallying up 4096+ CPUs. So it is not impossible.
741 */
742 smp_rmb();
743 for_each_possible_cpu(cpu)
744 incs += per_cpu_ptr(mod->refptr, cpu)->incs;
745 return incs - decs;
746}
747EXPORT_SYMBOL(module_refcount);
748
749/* This exists whether we can unload or not */
750static void free_module(struct module *mod);
751
752static void wait_for_zero_refcount(struct module *mod)
753{
754 /* Since we might sleep for some time, release the mutex first */
755 mutex_unlock(&module_mutex);
756 for (;;) {
757 pr_debug("Looking at refcount...\n");
758 set_current_state(TASK_UNINTERRUPTIBLE);
759 if (module_refcount(mod) == 0)
760 break;
761 schedule();
762 }
763 current->state = TASK_RUNNING;
764 mutex_lock(&module_mutex);
765}
766
767SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
768 unsigned int, flags)
769{
770 struct module *mod;
771 char name[MODULE_NAME_LEN];
772 int ret, forced = 0;
773
774 if (!capable(CAP_SYS_MODULE) || modules_disabled)
775 return -EPERM;
776
777 if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
778 return -EFAULT;
779 name[MODULE_NAME_LEN-1] = '\0';
780
781 if (mutex_lock_interruptible(&module_mutex) != 0)
782 return -EINTR;
783
784 mod = find_module(name);
785 if (!mod) {
786 ret = -ENOENT;
787 goto out;
788 }
789
790 if (!list_empty(&mod->source_list)) {
791 /* Other modules depend on us: get rid of them first. */
792 ret = -EWOULDBLOCK;
793 goto out;
794 }
795
796 /* Doing init or already dying? */
797 if (mod->state != MODULE_STATE_LIVE) {
798 /* FIXME: if (force), slam module count and wake up
799 waiter --RR */
800 pr_debug("%s already dying\n", mod->name);
801 ret = -EBUSY;
802 goto out;
803 }
804
805 /* If it has an init func, it must have an exit func to unload */
806 if (mod->init && !mod->exit) {
807 forced = try_force_unload(flags);
808 if (!forced) {
809 /* This module can't be removed */
810 ret = -EBUSY;
811 goto out;
812 }
813 }
814
815 /* Set this up before setting mod->state */
816 mod->waiter = current;
817
818 /* Stop the machine so refcounts can't move and disable module. */
819 ret = try_stop_module(mod, flags, &forced);
820 if (ret != 0)
821 goto out;
822
823 /* Never wait if forced. */
824 if (!forced && module_refcount(mod) != 0)
825 wait_for_zero_refcount(mod);
826
827 mutex_unlock(&module_mutex);
828 /* Final destruction now no one is using it. */
829 if (mod->exit != NULL)
830 mod->exit();
831 blocking_notifier_call_chain(&module_notify_list,
832 MODULE_STATE_GOING, mod);
833 async_synchronize_full();
834
835 /* Store the name of the last unloaded module for diagnostic purposes */
836 strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
837
838 free_module(mod);
839 return 0;
840out:
841 mutex_unlock(&module_mutex);
842 return ret;
843}
844
845static inline void print_unload_info(struct seq_file *m, struct module *mod)
846{
847 struct module_use *use;
848 int printed_something = 0;
849
850 seq_printf(m, " %lu ", module_refcount(mod));
851
852 /* Always include a trailing , so userspace can differentiate
853 between this and the old multi-field proc format. */
854 list_for_each_entry(use, &mod->source_list, source_list) {
855 printed_something = 1;
856 seq_printf(m, "%s,", use->source->name);
857 }
858
859 if (mod->init != NULL && mod->exit == NULL) {
860 printed_something = 1;
861 seq_printf(m, "[permanent],");
862 }
863
864 if (!printed_something)
865 seq_printf(m, "-");
866}
867
868void __symbol_put(const char *symbol)
869{
870 struct module *owner;
871
872 preempt_disable();
873 if (!find_symbol(symbol, &owner, NULL, true, false))
874 BUG();
875 module_put(owner);
876 preempt_enable();
877}
878EXPORT_SYMBOL(__symbol_put);
879
880/* Note this assumes addr is a function, which it currently always is. */
881void symbol_put_addr(void *addr)
882{
883 struct module *modaddr;
884 unsigned long a = (unsigned long)dereference_function_descriptor(addr);
885
886 if (core_kernel_text(a))
887 return;
888
889 /* module_text_address is safe here: we're supposed to have reference
890 * to module from symbol_get, so it can't go away. */
891 modaddr = __module_text_address(a);
892 BUG_ON(!modaddr);
893 module_put(modaddr);
894}
895EXPORT_SYMBOL_GPL(symbol_put_addr);
896
897static ssize_t show_refcnt(struct module_attribute *mattr,
898 struct module_kobject *mk, char *buffer)
899{
900 return sprintf(buffer, "%lu\n", module_refcount(mk->mod));
901}
902
903static struct module_attribute modinfo_refcnt =
904 __ATTR(refcnt, 0444, show_refcnt, NULL);
905
906void module_put(struct module *module)
907{
908 if (module) {
909 preempt_disable();
910 smp_wmb(); /* see comment in module_refcount */
911 __this_cpu_inc(module->refptr->decs);
912
913 trace_module_put(module, _RET_IP_);
914 /* Maybe they're waiting for us to drop reference? */
915 if (unlikely(!module_is_live(module)))
916 wake_up_process(module->waiter);
917 preempt_enable();
918 }
919}
920EXPORT_SYMBOL(module_put);
921
922#else /* !CONFIG_MODULE_UNLOAD */
923static inline void print_unload_info(struct seq_file *m, struct module *mod)
924{
925 /* We don't know the usage count, or what modules are using. */
926 seq_printf(m, " - -");
927}
928
929static inline void module_unload_free(struct module *mod)
930{
931}
932
933int ref_module(struct module *a, struct module *b)
934{
935 return strong_try_module_get(b);
936}
937EXPORT_SYMBOL_GPL(ref_module);
938
939static inline int module_unload_init(struct module *mod)
940{
941 return 0;
942}
943#endif /* CONFIG_MODULE_UNLOAD */
944
945static size_t module_flags_taint(struct module *mod, char *buf)
946{
947 size_t l = 0;
948
949 if (mod->taints & (1 << TAINT_PROPRIETARY_MODULE))
950 buf[l++] = 'P';
951 if (mod->taints & (1 << TAINT_OOT_MODULE))
952 buf[l++] = 'O';
953 if (mod->taints & (1 << TAINT_FORCED_MODULE))
954 buf[l++] = 'F';
955 if (mod->taints & (1 << TAINT_CRAP))
956 buf[l++] = 'C';
957 /*
958 * TAINT_FORCED_RMMOD: could be added.
959 * TAINT_UNSAFE_SMP, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't
960 * apply to modules.
961 */
962 return l;
963}
964
965static ssize_t show_initstate(struct module_attribute *mattr,
966 struct module_kobject *mk, char *buffer)
967{
968 const char *state = "unknown";
969
970 switch (mk->mod->state) {
971 case MODULE_STATE_LIVE:
972 state = "live";
973 break;
974 case MODULE_STATE_COMING:
975 state = "coming";
976 break;
977 case MODULE_STATE_GOING:
978 state = "going";
979 break;
980 }
981 return sprintf(buffer, "%s\n", state);
982}
983
984static struct module_attribute modinfo_initstate =
985 __ATTR(initstate, 0444, show_initstate, NULL);
986
987static ssize_t store_uevent(struct module_attribute *mattr,
988 struct module_kobject *mk,
989 const char *buffer, size_t count)
990{
991 enum kobject_action action;
992
993 if (kobject_action_type(buffer, count, &action) == 0)
994 kobject_uevent(&mk->kobj, action);
995 return count;
996}
997
998struct module_attribute module_uevent =
999 __ATTR(uevent, 0200, NULL, store_uevent);
1000
1001static ssize_t show_coresize(struct module_attribute *mattr,
1002 struct module_kobject *mk, char *buffer)
1003{
1004 return sprintf(buffer, "%u\n", mk->mod->core_size);
1005}
1006
1007static struct module_attribute modinfo_coresize =
1008 __ATTR(coresize, 0444, show_coresize, NULL);
1009
1010static ssize_t show_initsize(struct module_attribute *mattr,
1011 struct module_kobject *mk, char *buffer)
1012{
1013 return sprintf(buffer, "%u\n", mk->mod->init_size);
1014}
1015
1016static struct module_attribute modinfo_initsize =
1017 __ATTR(initsize, 0444, show_initsize, NULL);
1018
1019static ssize_t show_taint(struct module_attribute *mattr,
1020 struct module_kobject *mk, char *buffer)
1021{
1022 size_t l;
1023
1024 l = module_flags_taint(mk->mod, buffer);
1025 buffer[l++] = '\n';
1026 return l;
1027}
1028
1029static struct module_attribute modinfo_taint =
1030 __ATTR(taint, 0444, show_taint, NULL);
1031
1032static struct module_attribute *modinfo_attrs[] = {
1033 &module_uevent,
1034 &modinfo_version,
1035 &modinfo_srcversion,
1036 &modinfo_initstate,
1037 &modinfo_coresize,
1038 &modinfo_initsize,
1039 &modinfo_taint,
1040#ifdef CONFIG_MODULE_UNLOAD
1041 &modinfo_refcnt,
1042#endif
1043 NULL,
1044};
1045
1046static const char vermagic[] = VERMAGIC_STRING;
1047
1048static int try_to_force_load(struct module *mod, const char *reason)
1049{
1050#ifdef CONFIG_MODULE_FORCE_LOAD
1051 if (!test_taint(TAINT_FORCED_MODULE))
1052 printk(KERN_WARNING "%s: %s: kernel tainted.\n",
1053 mod->name, reason);
1054 add_taint_module(mod, TAINT_FORCED_MODULE);
1055 return 0;
1056#else
1057 return -ENOEXEC;
1058#endif
1059}
1060
1061#ifdef CONFIG_MODVERSIONS
1062/* If the arch applies (non-zero) relocations to kernel kcrctab, unapply it. */
1063static unsigned long maybe_relocated(unsigned long crc,
1064 const struct module *crc_owner)
1065{
1066#ifdef ARCH_RELOCATES_KCRCTAB
1067 if (crc_owner == NULL)
1068 return crc - (unsigned long)reloc_start;
1069#endif
1070 return crc;
1071}
1072
1073static int check_version(Elf_Shdr *sechdrs,
1074 unsigned int versindex,
1075 const char *symname,
1076 struct module *mod,
1077 const unsigned long *crc,
1078 const struct module *crc_owner)
1079{
1080 unsigned int i, num_versions;
1081 struct modversion_info *versions;
1082
1083 /* Exporting module didn't supply crcs? OK, we're already tainted. */
1084 if (!crc)
1085 return 1;
1086
1087 /* No versions at all? modprobe --force does this. */
1088 if (versindex == 0)
1089 return try_to_force_load(mod, symname) == 0;
1090
1091 versions = (void *) sechdrs[versindex].sh_addr;
1092 num_versions = sechdrs[versindex].sh_size
1093 / sizeof(struct modversion_info);
1094
1095 for (i = 0; i < num_versions; i++) {
1096 if (strcmp(versions[i].name, symname) != 0)
1097 continue;
1098
1099 if (versions[i].crc == maybe_relocated(*crc, crc_owner))
1100 return 1;
1101 pr_debug("Found checksum %lX vs module %lX\n",
1102 maybe_relocated(*crc, crc_owner), versions[i].crc);
1103 goto bad_version;
1104 }
1105
1106 printk(KERN_WARNING "%s: no symbol version for %s\n",
1107 mod->name, symname);
1108 return 0;
1109
1110bad_version:
1111 printk("%s: disagrees about version of symbol %s\n",
1112 mod->name, symname);
1113 return 0;
1114}
1115
1116static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1117 unsigned int versindex,
1118 struct module *mod)
1119{
1120 const unsigned long *crc;
1121
1122 /* Since this should be found in kernel (which can't be removed),
1123 * no locking is necessary. */
1124 if (!find_symbol(MODULE_SYMBOL_PREFIX "module_layout", NULL,
1125 &crc, true, false))
1126 BUG();
1127 return check_version(sechdrs, versindex, "module_layout", mod, crc,
1128 NULL);
1129}
1130
1131/* First part is kernel version, which we ignore if module has crcs. */
1132static inline int same_magic(const char *amagic, const char *bmagic,
1133 bool has_crcs)
1134{
1135 if (has_crcs) {
1136 amagic += strcspn(amagic, " ");
1137 bmagic += strcspn(bmagic, " ");
1138 }
1139 return strcmp(amagic, bmagic) == 0;
1140}
1141#else
1142static inline int check_version(Elf_Shdr *sechdrs,
1143 unsigned int versindex,
1144 const char *symname,
1145 struct module *mod,
1146 const unsigned long *crc,
1147 const struct module *crc_owner)
1148{
1149 return 1;
1150}
1151
1152static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1153 unsigned int versindex,
1154 struct module *mod)
1155{
1156 return 1;
1157}
1158
1159static inline int same_magic(const char *amagic, const char *bmagic,
1160 bool has_crcs)
1161{
1162 return strcmp(amagic, bmagic) == 0;
1163}
1164#endif /* CONFIG_MODVERSIONS */
1165
1166/* Resolve a symbol for this module. I.e. if we find one, record usage. */
1167static const struct kernel_symbol *resolve_symbol(struct module *mod,
1168 const struct load_info *info,
1169 const char *name,
1170 char ownername[])
1171{
1172 struct module *owner;
1173 const struct kernel_symbol *sym;
1174 const unsigned long *crc;
1175 int err;
1176
1177 mutex_lock(&module_mutex);
1178 sym = find_symbol(name, &owner, &crc,
1179 !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
1180 if (!sym)
1181 goto unlock;
1182
1183 if (!check_version(info->sechdrs, info->index.vers, name, mod, crc,
1184 owner)) {
1185 sym = ERR_PTR(-EINVAL);
1186 goto getname;
1187 }
1188
1189 err = ref_module(mod, owner);
1190 if (err) {
1191 sym = ERR_PTR(err);
1192 goto getname;
1193 }
1194
1195getname:
1196 /* We must make copy under the lock if we failed to get ref. */
1197 strncpy(ownername, module_name(owner), MODULE_NAME_LEN);
1198unlock:
1199 mutex_unlock(&module_mutex);
1200 return sym;
1201}
1202
1203static const struct kernel_symbol *
1204resolve_symbol_wait(struct module *mod,
1205 const struct load_info *info,
1206 const char *name)
1207{
1208 const struct kernel_symbol *ksym;
1209 char owner[MODULE_NAME_LEN];
1210
1211 if (wait_event_interruptible_timeout(module_wq,
1212 !IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
1213 || PTR_ERR(ksym) != -EBUSY,
1214 30 * HZ) <= 0) {
1215 printk(KERN_WARNING "%s: gave up waiting for init of module %s.\n",
1216 mod->name, owner);
1217 }
1218 return ksym;
1219}
1220
1221/*
1222 * /sys/module/foo/sections stuff
1223 * J. Corbet <[email protected]>
1224 */
1225#ifdef CONFIG_SYSFS
1226
1227#ifdef CONFIG_KALLSYMS
1228static inline bool sect_empty(const Elf_Shdr *sect)
1229{
1230 return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
1231}
1232
1233struct module_sect_attr
1234{
1235 struct module_attribute mattr;
1236 char *name;
1237 unsigned long address;
1238};
1239
1240struct module_sect_attrs
1241{
1242 struct attribute_group grp;
1243 unsigned int nsections;
1244 struct module_sect_attr attrs[0];
1245};
1246
1247static ssize_t module_sect_show(struct module_attribute *mattr,
1248 struct module_kobject *mk, char *buf)
1249{
1250 struct module_sect_attr *sattr =
1251 container_of(mattr, struct module_sect_attr, mattr);
1252 return sprintf(buf, "0x%pK\n", (void *)sattr->address);
1253}
1254
1255static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
1256{
1257 unsigned int section;
1258
1259 for (section = 0; section < sect_attrs->nsections; section++)
1260 kfree(sect_attrs->attrs[section].name);
1261 kfree(sect_attrs);
1262}
1263
1264static void add_sect_attrs(struct module *mod, const struct load_info *info)
1265{
1266 unsigned int nloaded = 0, i, size[2];
1267 struct module_sect_attrs *sect_attrs;
1268 struct module_sect_attr *sattr;
1269 struct attribute **gattr;
1270
1271 /* Count loaded sections and allocate structures */
1272 for (i = 0; i < info->hdr->e_shnum; i++)
1273 if (!sect_empty(&info->sechdrs[i]))
1274 nloaded++;
1275 size[0] = ALIGN(sizeof(*sect_attrs)
1276 + nloaded * sizeof(sect_attrs->attrs[0]),
1277 sizeof(sect_attrs->grp.attrs[0]));
1278 size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]);
1279 sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
1280 if (sect_attrs == NULL)
1281 return;
1282
1283 /* Setup section attributes. */
1284 sect_attrs->grp.name = "sections";
1285 sect_attrs->grp.attrs = (void *)sect_attrs + size[0];
1286
1287 sect_attrs->nsections = 0;
1288 sattr = &sect_attrs->attrs[0];
1289 gattr = &sect_attrs->grp.attrs[0];
1290 for (i = 0; i < info->hdr->e_shnum; i++) {
1291 Elf_Shdr *sec = &info->sechdrs[i];
1292 if (sect_empty(sec))
1293 continue;
1294 sattr->address = sec->sh_addr;
1295 sattr->name = kstrdup(info->secstrings + sec->sh_name,
1296 GFP_KERNEL);
1297 if (sattr->name == NULL)
1298 goto out;
1299 sect_attrs->nsections++;
1300 sysfs_attr_init(&sattr->mattr.attr);
1301 sattr->mattr.show = module_sect_show;
1302 sattr->mattr.store = NULL;
1303 sattr->mattr.attr.name = sattr->name;
1304 sattr->mattr.attr.mode = S_IRUGO;
1305 *(gattr++) = &(sattr++)->mattr.attr;
1306 }
1307 *gattr = NULL;
1308
1309 if (sysfs_create_group(&mod->mkobj.kobj, &sect_attrs->grp))
1310 goto out;
1311
1312 mod->sect_attrs = sect_attrs;
1313 return;
1314 out:
1315 free_sect_attrs(sect_attrs);
1316}
1317
1318static void remove_sect_attrs(struct module *mod)
1319{
1320 if (mod->sect_attrs) {
1321 sysfs_remove_group(&mod->mkobj.kobj,
1322 &mod->sect_attrs->grp);
1323 /* We are positive that no one is using any sect attrs
1324 * at this point. Deallocate immediately. */
1325 free_sect_attrs(mod->sect_attrs);
1326 mod->sect_attrs = NULL;
1327 }
1328}
1329
1330/*
1331 * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
1332 */
1333
1334struct module_notes_attrs {
1335 struct kobject *dir;
1336 unsigned int notes;
1337 struct bin_attribute attrs[0];
1338};
1339
1340static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
1341 struct bin_attribute *bin_attr,
1342 char *buf, loff_t pos, size_t count)
1343{
1344 /*
1345 * The caller checked the pos and count against our size.
1346 */
1347 memcpy(buf, bin_attr->private + pos, count);
1348 return count;
1349}
1350
1351static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
1352 unsigned int i)
1353{
1354 if (notes_attrs->dir) {
1355 while (i-- > 0)
1356 sysfs_remove_bin_file(notes_attrs->dir,
1357 &notes_attrs->attrs[i]);
1358 kobject_put(notes_attrs->dir);
1359 }
1360 kfree(notes_attrs);
1361}
1362
1363static void add_notes_attrs(struct module *mod, const struct load_info *info)
1364{
1365 unsigned int notes, loaded, i;
1366 struct module_notes_attrs *notes_attrs;
1367 struct bin_attribute *nattr;
1368
1369 /* failed to create section attributes, so can't create notes */
1370 if (!mod->sect_attrs)
1371 return;
1372
1373 /* Count notes sections and allocate structures. */
1374 notes = 0;
1375 for (i = 0; i < info->hdr->e_shnum; i++)
1376 if (!sect_empty(&info->sechdrs[i]) &&
1377 (info->sechdrs[i].sh_type == SHT_NOTE))
1378 ++notes;
1379
1380 if (notes == 0)
1381 return;
1382
1383 notes_attrs = kzalloc(sizeof(*notes_attrs)
1384 + notes * sizeof(notes_attrs->attrs[0]),
1385 GFP_KERNEL);
1386 if (notes_attrs == NULL)
1387 return;
1388
1389 notes_attrs->notes = notes;
1390 nattr = &notes_attrs->attrs[0];
1391 for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
1392 if (sect_empty(&info->sechdrs[i]))
1393 continue;
1394 if (info->sechdrs[i].sh_type == SHT_NOTE) {
1395 sysfs_bin_attr_init(nattr);
1396 nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
1397 nattr->attr.mode = S_IRUGO;
1398 nattr->size = info->sechdrs[i].sh_size;
1399 nattr->private = (void *) info->sechdrs[i].sh_addr;
1400 nattr->read = module_notes_read;
1401 ++nattr;
1402 }
1403 ++loaded;
1404 }
1405
1406 notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
1407 if (!notes_attrs->dir)
1408 goto out;
1409
1410 for (i = 0; i < notes; ++i)
1411 if (sysfs_create_bin_file(notes_attrs->dir,
1412 &notes_attrs->attrs[i]))
1413 goto out;
1414
1415 mod->notes_attrs = notes_attrs;
1416 return;
1417
1418 out:
1419 free_notes_attrs(notes_attrs, i);
1420}
1421
1422static void remove_notes_attrs(struct module *mod)
1423{
1424 if (mod->notes_attrs)
1425 free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
1426}
1427
1428#else
1429
1430static inline void add_sect_attrs(struct module *mod,
1431 const struct load_info *info)
1432{
1433}
1434
1435static inline void remove_sect_attrs(struct module *mod)
1436{
1437}
1438
1439static inline void add_notes_attrs(struct module *mod,
1440 const struct load_info *info)
1441{
1442}
1443
1444static inline void remove_notes_attrs(struct module *mod)
1445{
1446}
1447#endif /* CONFIG_KALLSYMS */
1448
1449static void add_usage_links(struct module *mod)
1450{
1451#ifdef CONFIG_MODULE_UNLOAD
1452 struct module_use *use;
1453 int nowarn;
1454
1455 mutex_lock(&module_mutex);
1456 list_for_each_entry(use, &mod->target_list, target_list) {
1457 nowarn = sysfs_create_link(use->target->holders_dir,
1458 &mod->mkobj.kobj, mod->name);
1459 }
1460 mutex_unlock(&module_mutex);
1461#endif
1462}
1463
1464static void del_usage_links(struct module *mod)
1465{
1466#ifdef CONFIG_MODULE_UNLOAD
1467 struct module_use *use;
1468
1469 mutex_lock(&module_mutex);
1470 list_for_each_entry(use, &mod->target_list, target_list)
1471 sysfs_remove_link(use->target->holders_dir, mod->name);
1472 mutex_unlock(&module_mutex);
1473#endif
1474}
1475
1476static int module_add_modinfo_attrs(struct module *mod)
1477{
1478 struct module_attribute *attr;
1479 struct module_attribute *temp_attr;
1480 int error = 0;
1481 int i;
1482
1483 mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
1484 (ARRAY_SIZE(modinfo_attrs) + 1)),
1485 GFP_KERNEL);
1486 if (!mod->modinfo_attrs)
1487 return -ENOMEM;
1488
1489 temp_attr = mod->modinfo_attrs;
1490 for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
1491 if (!attr->test ||
1492 (attr->test && attr->test(mod))) {
1493 memcpy(temp_attr, attr, sizeof(*temp_attr));
1494 sysfs_attr_init(&temp_attr->attr);
1495 error = sysfs_create_file(&mod->mkobj.kobj,&temp_attr->attr);
1496 ++temp_attr;
1497 }
1498 }
1499 return error;
1500}
1501
1502static void module_remove_modinfo_attrs(struct module *mod)
1503{
1504 struct module_attribute *attr;
1505 int i;
1506
1507 for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
1508 /* pick a field to test for end of list */
1509 if (!attr->attr.name)
1510 break;
1511 sysfs_remove_file(&mod->mkobj.kobj,&attr->attr);
1512 if (attr->free)
1513 attr->free(mod);
1514 }
1515 kfree(mod->modinfo_attrs);
1516}
1517
1518static int mod_sysfs_init(struct module *mod)
1519{
1520 int err;
1521 struct kobject *kobj;
1522
1523 if (!module_sysfs_initialized) {
1524 printk(KERN_ERR "%s: module sysfs not initialized\n",
1525 mod->name);
1526 err = -EINVAL;
1527 goto out;
1528 }
1529
1530 kobj = kset_find_obj(module_kset, mod->name);
1531 if (kobj) {
1532 printk(KERN_ERR "%s: module is already loaded\n", mod->name);
1533 kobject_put(kobj);
1534 err = -EINVAL;
1535 goto out;
1536 }
1537
1538 mod->mkobj.mod = mod;
1539
1540 memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
1541 mod->mkobj.kobj.kset = module_kset;
1542 err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
1543 "%s", mod->name);
1544 if (err)
1545 kobject_put(&mod->mkobj.kobj);
1546
1547 /* delay uevent until full sysfs population */
1548out:
1549 return err;
1550}
1551
1552static int mod_sysfs_setup(struct module *mod,
1553 const struct load_info *info,
1554 struct kernel_param *kparam,
1555 unsigned int num_params)
1556{
1557 int err;
1558
1559 err = mod_sysfs_init(mod);
1560 if (err)
1561 goto out;
1562
1563 mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1564 if (!mod->holders_dir) {
1565 err = -ENOMEM;
1566 goto out_unreg;
1567 }
1568
1569 err = module_param_sysfs_setup(mod, kparam, num_params);
1570 if (err)
1571 goto out_unreg_holders;
1572
1573 err = module_add_modinfo_attrs(mod);
1574 if (err)
1575 goto out_unreg_param;
1576
1577 add_usage_links(mod);
1578 add_sect_attrs(mod, info);
1579 add_notes_attrs(mod, info);
1580
1581 kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
1582 return 0;
1583
1584out_unreg_param:
1585 module_param_sysfs_remove(mod);
1586out_unreg_holders:
1587 kobject_put(mod->holders_dir);
1588out_unreg:
1589 kobject_put(&mod->mkobj.kobj);
1590out:
1591 return err;
1592}
1593
1594static void mod_sysfs_fini(struct module *mod)
1595{
1596 remove_notes_attrs(mod);
1597 remove_sect_attrs(mod);
1598 kobject_put(&mod->mkobj.kobj);
1599}
1600
1601#else /* !CONFIG_SYSFS */
1602
1603static int mod_sysfs_setup(struct module *mod,
1604 const struct load_info *info,
1605 struct kernel_param *kparam,
1606 unsigned int num_params)
1607{
1608 return 0;
1609}
1610
1611static void mod_sysfs_fini(struct module *mod)
1612{
1613}
1614
1615static void module_remove_modinfo_attrs(struct module *mod)
1616{
1617}
1618
1619static void del_usage_links(struct module *mod)
1620{
1621}
1622
1623#endif /* CONFIG_SYSFS */
1624
1625static void mod_sysfs_teardown(struct module *mod)
1626{
1627 del_usage_links(mod);
1628 module_remove_modinfo_attrs(mod);
1629 module_param_sysfs_remove(mod);
1630 kobject_put(mod->mkobj.drivers_dir);
1631 kobject_put(mod->holders_dir);
1632 mod_sysfs_fini(mod);
1633}
1634
1635/*
1636 * unlink the module with the whole machine is stopped with interrupts off
1637 * - this defends against kallsyms not taking locks
1638 */
1639static int __unlink_module(void *_mod)
1640{
1641 struct module *mod = _mod;
1642 list_del(&mod->list);
1643 module_bug_cleanup(mod);
1644 return 0;
1645}
1646
1647#ifdef CONFIG_DEBUG_SET_MODULE_RONX
1648/*
1649 * LKM RO/NX protection: protect module's text/ro-data
1650 * from modification and any data from execution.
1651 */
1652void set_page_attributes(void *start, void *end, int (*set)(unsigned long start, int num_pages))
1653{
1654 unsigned long begin_pfn = PFN_DOWN((unsigned long)start);
1655 unsigned long end_pfn = PFN_DOWN((unsigned long)end);
1656
1657 if (end_pfn > begin_pfn)
1658 set(begin_pfn << PAGE_SHIFT, end_pfn - begin_pfn);
1659}
1660
1661static void set_section_ro_nx(void *base,
1662 unsigned long text_size,
1663 unsigned long ro_size,
1664 unsigned long total_size)
1665{
1666 /* begin and end PFNs of the current subsection */
1667 unsigned long begin_pfn;
1668 unsigned long end_pfn;
1669
1670 /*
1671 * Set RO for module text and RO-data:
1672 * - Always protect first page.
1673 * - Do not protect last partial page.
1674 */
1675 if (ro_size > 0)
1676 set_page_attributes(base, base + ro_size, set_memory_ro);
1677
1678 /*
1679 * Set NX permissions for module data:
1680 * - Do not protect first partial page.
1681 * - Always protect last page.
1682 */
1683 if (total_size > text_size) {
1684 begin_pfn = PFN_UP((unsigned long)base + text_size);
1685 end_pfn = PFN_UP((unsigned long)base + total_size);
1686 if (end_pfn > begin_pfn)
1687 set_memory_nx(begin_pfn << PAGE_SHIFT, end_pfn - begin_pfn);
1688 }
1689}
1690
1691static void unset_module_core_ro_nx(struct module *mod)
1692{
1693 set_page_attributes(mod->module_core + mod->core_text_size,
1694 mod->module_core + mod->core_size,
1695 set_memory_x);
1696 set_page_attributes(mod->module_core,
1697 mod->module_core + mod->core_ro_size,
1698 set_memory_rw);
1699}
1700
1701static void unset_module_init_ro_nx(struct module *mod)
1702{
1703 set_page_attributes(mod->module_init + mod->init_text_size,
1704 mod->module_init + mod->init_size,
1705 set_memory_x);
1706 set_page_attributes(mod->module_init,
1707 mod->module_init + mod->init_ro_size,
1708 set_memory_rw);
1709}
1710
1711/* Iterate through all modules and set each module's text as RW */
1712void set_all_modules_text_rw(void)
1713{
1714 struct module *mod;
1715
1716 mutex_lock(&module_mutex);
1717 list_for_each_entry_rcu(mod, &modules, list) {
1718 if ((mod->module_core) && (mod->core_text_size)) {
1719 set_page_attributes(mod->module_core,
1720 mod->module_core + mod->core_text_size,
1721 set_memory_rw);
1722 }
1723 if ((mod->module_init) && (mod->init_text_size)) {
1724 set_page_attributes(mod->module_init,
1725 mod->module_init + mod->init_text_size,
1726 set_memory_rw);
1727 }
1728 }
1729 mutex_unlock(&module_mutex);
1730}
1731
1732/* Iterate through all modules and set each module's text as RO */
1733void set_all_modules_text_ro(void)
1734{
1735 struct module *mod;
1736
1737 mutex_lock(&module_mutex);
1738 list_for_each_entry_rcu(mod, &modules, list) {
1739 if ((mod->module_core) && (mod->core_text_size)) {
1740 set_page_attributes(mod->module_core,
1741 mod->module_core + mod->core_text_size,
1742 set_memory_ro);
1743 }
1744 if ((mod->module_init) && (mod->init_text_size)) {
1745 set_page_attributes(mod->module_init,
1746 mod->module_init + mod->init_text_size,
1747 set_memory_ro);
1748 }
1749 }
1750 mutex_unlock(&module_mutex);
1751}
1752#else
1753static inline void set_section_ro_nx(void *base, unsigned long text_size, unsigned long ro_size, unsigned long total_size) { }
1754static void unset_module_core_ro_nx(struct module *mod) { }
1755static void unset_module_init_ro_nx(struct module *mod) { }
1756#endif
1757
1758void __weak module_free(struct module *mod, void *module_region)
1759{
1760 vfree(module_region);
1761}
1762
1763void __weak module_arch_cleanup(struct module *mod)
1764{
1765}
1766
1767/* Free a module, remove from lists, etc. */
1768static void free_module(struct module *mod)
1769{
1770 trace_module_free(mod);
1771
1772 /* Delete from various lists */
1773 mutex_lock(&module_mutex);
1774 stop_machine(__unlink_module, mod, NULL);
1775 mutex_unlock(&module_mutex);
1776 mod_sysfs_teardown(mod);
1777
1778 /* Remove dynamic debug info */
1779 ddebug_remove_module(mod->name);
1780
1781 /* Arch-specific cleanup. */
1782 module_arch_cleanup(mod);
1783
1784 /* Module unload stuff */
1785 module_unload_free(mod);
1786
1787 /* Free any allocated parameters. */
1788 destroy_params(mod->kp, mod->num_kp);
1789
1790 /* This may be NULL, but that's OK */
1791 unset_module_init_ro_nx(mod);
1792 module_free(mod, mod->module_init);
1793 kfree(mod->args);
1794 percpu_modfree(mod);
1795
1796 /* Free lock-classes: */
1797 lockdep_free_key_range(mod->module_core, mod->core_size);
1798
1799 /* Finally, free the core (containing the module structure) */
1800 unset_module_core_ro_nx(mod);
1801 module_free(mod, mod->module_core);
1802
1803#ifdef CONFIG_MPU
1804 update_protections(current->mm);
1805#endif
1806}
1807
1808void *__symbol_get(const char *symbol)
1809{
1810 struct module *owner;
1811 const struct kernel_symbol *sym;
1812
1813 preempt_disable();
1814 sym = find_symbol(symbol, &owner, NULL, true, true);
1815 if (sym && strong_try_module_get(owner))
1816 sym = NULL;
1817 preempt_enable();
1818
1819 return sym ? (void *)sym->value : NULL;
1820}
1821EXPORT_SYMBOL_GPL(__symbol_get);
1822
1823/*
1824 * Ensure that an exported symbol [global namespace] does not already exist
1825 * in the kernel or in some other module's exported symbol table.
1826 *
1827 * You must hold the module_mutex.
1828 */
1829static int verify_export_symbols(struct module *mod)
1830{
1831 unsigned int i;
1832 struct module *owner;
1833 const struct kernel_symbol *s;
1834 struct {
1835 const struct kernel_symbol *sym;
1836 unsigned int num;
1837 } arr[] = {
1838 { mod->syms, mod->num_syms },
1839 { mod->gpl_syms, mod->num_gpl_syms },
1840 { mod->gpl_future_syms, mod->num_gpl_future_syms },
1841#ifdef CONFIG_UNUSED_SYMBOLS
1842 { mod->unused_syms, mod->num_unused_syms },
1843 { mod->unused_gpl_syms, mod->num_unused_gpl_syms },
1844#endif
1845 };
1846
1847 for (i = 0; i < ARRAY_SIZE(arr); i++) {
1848 for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
1849 if (find_symbol(s->name, &owner, NULL, true, false)) {
1850 printk(KERN_ERR
1851 "%s: exports duplicate symbol %s"
1852 " (owned by %s)\n",
1853 mod->name, s->name, module_name(owner));
1854 return -ENOEXEC;
1855 }
1856 }
1857 }
1858 return 0;
1859}
1860
1861/* Change all symbols so that st_value encodes the pointer directly. */
1862static int simplify_symbols(struct module *mod, const struct load_info *info)
1863{
1864 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
1865 Elf_Sym *sym = (void *)symsec->sh_addr;
1866 unsigned long secbase;
1867 unsigned int i;
1868 int ret = 0;
1869 const struct kernel_symbol *ksym;
1870
1871 for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
1872 const char *name = info->strtab + sym[i].st_name;
1873
1874 switch (sym[i].st_shndx) {
1875 case SHN_COMMON:
1876 /* We compiled with -fno-common. These are not
1877 supposed to happen. */
1878 pr_debug("Common symbol: %s\n", name);
1879 printk("%s: please compile with -fno-common\n",
1880 mod->name);
1881 ret = -ENOEXEC;
1882 break;
1883
1884 case SHN_ABS:
1885 /* Don't need to do anything */
1886 pr_debug("Absolute symbol: 0x%08lx\n",
1887 (long)sym[i].st_value);
1888 break;
1889
1890 case SHN_UNDEF:
1891 ksym = resolve_symbol_wait(mod, info, name);
1892 /* Ok if resolved. */
1893 if (ksym && !IS_ERR(ksym)) {
1894 sym[i].st_value = ksym->value;
1895 break;
1896 }
1897
1898 /* Ok if weak. */
1899 if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
1900 break;
1901
1902 printk(KERN_WARNING "%s: Unknown symbol %s (err %li)\n",
1903 mod->name, name, PTR_ERR(ksym));
1904 ret = PTR_ERR(ksym) ?: -ENOENT;
1905 break;
1906
1907 default:
1908 /* Divert to percpu allocation if a percpu var. */
1909 if (sym[i].st_shndx == info->index.pcpu)
1910 secbase = (unsigned long)mod_percpu(mod);
1911 else
1912 secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
1913 sym[i].st_value += secbase;
1914 break;
1915 }
1916 }
1917
1918 return ret;
1919}
1920
1921int __weak apply_relocate(Elf_Shdr *sechdrs,
1922 const char *strtab,
1923 unsigned int symindex,
1924 unsigned int relsec,
1925 struct module *me)
1926{
1927 pr_err("module %s: REL relocation unsupported\n", me->name);
1928 return -ENOEXEC;
1929}
1930
1931int __weak apply_relocate_add(Elf_Shdr *sechdrs,
1932 const char *strtab,
1933 unsigned int symindex,
1934 unsigned int relsec,
1935 struct module *me)
1936{
1937 pr_err("module %s: RELA relocation unsupported\n", me->name);
1938 return -ENOEXEC;
1939}
1940
1941static int apply_relocations(struct module *mod, const struct load_info *info)
1942{
1943 unsigned int i;
1944 int err = 0;
1945
1946 /* Now do relocations. */
1947 for (i = 1; i < info->hdr->e_shnum; i++) {
1948 unsigned int infosec = info->sechdrs[i].sh_info;
1949
1950 /* Not a valid relocation section? */
1951 if (infosec >= info->hdr->e_shnum)
1952 continue;
1953
1954 /* Don't bother with non-allocated sections */
1955 if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
1956 continue;
1957
1958 if (info->sechdrs[i].sh_type == SHT_REL)
1959 err = apply_relocate(info->sechdrs, info->strtab,
1960 info->index.sym, i, mod);
1961 else if (info->sechdrs[i].sh_type == SHT_RELA)
1962 err = apply_relocate_add(info->sechdrs, info->strtab,
1963 info->index.sym, i, mod);
1964 if (err < 0)
1965 break;
1966 }
1967 return err;
1968}
1969
1970/* Additional bytes needed by arch in front of individual sections */
1971unsigned int __weak arch_mod_section_prepend(struct module *mod,
1972 unsigned int section)
1973{
1974 /* default implementation just returns zero */
1975 return 0;
1976}
1977
1978/* Update size with this section: return offset. */
1979static long get_offset(struct module *mod, unsigned int *size,
1980 Elf_Shdr *sechdr, unsigned int section)
1981{
1982 long ret;
1983
1984 *size += arch_mod_section_prepend(mod, section);
1985 ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
1986 *size = ret + sechdr->sh_size;
1987 return ret;
1988}
1989
1990/* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
1991 might -- code, read-only data, read-write data, small data. Tally
1992 sizes, and place the offsets into sh_entsize fields: high bit means it
1993 belongs in init. */
1994static void layout_sections(struct module *mod, struct load_info *info)
1995{
1996 static unsigned long const masks[][2] = {
1997 /* NOTE: all executable code must be the first section
1998 * in this array; otherwise modify the text_size
1999 * finder in the two loops below */
2000 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
2001 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
2002 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
2003 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
2004 };
2005 unsigned int m, i;
2006
2007 for (i = 0; i < info->hdr->e_shnum; i++)
2008 info->sechdrs[i].sh_entsize = ~0UL;
2009
2010 pr_debug("Core section allocation order:\n");
2011 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2012 for (i = 0; i < info->hdr->e_shnum; ++i) {
2013 Elf_Shdr *s = &info->sechdrs[i];
2014 const char *sname = info->secstrings + s->sh_name;
2015
2016 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2017 || (s->sh_flags & masks[m][1])
2018 || s->sh_entsize != ~0UL
2019 || strstarts(sname, ".init"))
2020 continue;
2021 s->sh_entsize = get_offset(mod, &mod->core_size, s, i);
2022 pr_debug("\t%s\n", sname);
2023 }
2024 switch (m) {
2025 case 0: /* executable */
2026 mod->core_size = debug_align(mod->core_size);
2027 mod->core_text_size = mod->core_size;
2028 break;
2029 case 1: /* RO: text and ro-data */
2030 mod->core_size = debug_align(mod->core_size);
2031 mod->core_ro_size = mod->core_size;
2032 break;
2033 case 3: /* whole core */
2034 mod->core_size = debug_align(mod->core_size);
2035 break;
2036 }
2037 }
2038
2039 pr_debug("Init section allocation order:\n");
2040 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2041 for (i = 0; i < info->hdr->e_shnum; ++i) {
2042 Elf_Shdr *s = &info->sechdrs[i];
2043 const char *sname = info->secstrings + s->sh_name;
2044
2045 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2046 || (s->sh_flags & masks[m][1])
2047 || s->sh_entsize != ~0UL
2048 || !strstarts(sname, ".init"))
2049 continue;
2050 s->sh_entsize = (get_offset(mod, &mod->init_size, s, i)
2051 | INIT_OFFSET_MASK);
2052 pr_debug("\t%s\n", sname);
2053 }
2054 switch (m) {
2055 case 0: /* executable */
2056 mod->init_size = debug_align(mod->init_size);
2057 mod->init_text_size = mod->init_size;
2058 break;
2059 case 1: /* RO: text and ro-data */
2060 mod->init_size = debug_align(mod->init_size);
2061 mod->init_ro_size = mod->init_size;
2062 break;
2063 case 3: /* whole init */
2064 mod->init_size = debug_align(mod->init_size);
2065 break;
2066 }
2067 }
2068}
2069
2070static void set_license(struct module *mod, const char *license)
2071{
2072 if (!license)
2073 license = "unspecified";
2074
2075 if (!license_is_gpl_compatible(license)) {
2076 if (!test_taint(TAINT_PROPRIETARY_MODULE))
2077 printk(KERN_WARNING "%s: module license '%s' taints "
2078 "kernel.\n", mod->name, license);
2079 add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
2080 }
2081}
2082
2083/* Parse tag=value strings from .modinfo section */
2084static char *next_string(char *string, unsigned long *secsize)
2085{
2086 /* Skip non-zero chars */
2087 while (string[0]) {
2088 string++;
2089 if ((*secsize)-- <= 1)
2090 return NULL;
2091 }
2092
2093 /* Skip any zero padding. */
2094 while (!string[0]) {
2095 string++;
2096 if ((*secsize)-- <= 1)
2097 return NULL;
2098 }
2099 return string;
2100}
2101
2102static char *get_modinfo(struct load_info *info, const char *tag)
2103{
2104 char *p;
2105 unsigned int taglen = strlen(tag);
2106 Elf_Shdr *infosec = &info->sechdrs[info->index.info];
2107 unsigned long size = infosec->sh_size;
2108
2109 for (p = (char *)infosec->sh_addr; p; p = next_string(p, &size)) {
2110 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
2111 return p + taglen + 1;
2112 }
2113 return NULL;
2114}
2115
2116static void setup_modinfo(struct module *mod, struct load_info *info)
2117{
2118 struct module_attribute *attr;
2119 int i;
2120
2121 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2122 if (attr->setup)
2123 attr->setup(mod, get_modinfo(info, attr->attr.name));
2124 }
2125}
2126
2127static void free_modinfo(struct module *mod)
2128{
2129 struct module_attribute *attr;
2130 int i;
2131
2132 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2133 if (attr->free)
2134 attr->free(mod);
2135 }
2136}
2137
2138#ifdef CONFIG_KALLSYMS
2139
2140/* lookup symbol in given range of kernel_symbols */
2141static const struct kernel_symbol *lookup_symbol(const char *name,
2142 const struct kernel_symbol *start,
2143 const struct kernel_symbol *stop)
2144{
2145 return bsearch(name, start, stop - start,
2146 sizeof(struct kernel_symbol), cmp_name);
2147}
2148
2149static int is_exported(const char *name, unsigned long value,
2150 const struct module *mod)
2151{
2152 const struct kernel_symbol *ks;
2153 if (!mod)
2154 ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
2155 else
2156 ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
2157 return ks != NULL && ks->value == value;
2158}
2159
2160/* As per nm */
2161static char elf_type(const Elf_Sym *sym, const struct load_info *info)
2162{
2163 const Elf_Shdr *sechdrs = info->sechdrs;
2164
2165 if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
2166 if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
2167 return 'v';
2168 else
2169 return 'w';
2170 }
2171 if (sym->st_shndx == SHN_UNDEF)
2172 return 'U';
2173 if (sym->st_shndx == SHN_ABS)
2174 return 'a';
2175 if (sym->st_shndx >= SHN_LORESERVE)
2176 return '?';
2177 if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
2178 return 't';
2179 if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
2180 && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
2181 if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
2182 return 'r';
2183 else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2184 return 'g';
2185 else
2186 return 'd';
2187 }
2188 if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
2189 if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2190 return 's';
2191 else
2192 return 'b';
2193 }
2194 if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
2195 ".debug")) {
2196 return 'n';
2197 }
2198 return '?';
2199}
2200
2201static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
2202 unsigned int shnum)
2203{
2204 const Elf_Shdr *sec;
2205
2206 if (src->st_shndx == SHN_UNDEF
2207 || src->st_shndx >= shnum
2208 || !src->st_name)
2209 return false;
2210
2211 sec = sechdrs + src->st_shndx;
2212 if (!(sec->sh_flags & SHF_ALLOC)
2213#ifndef CONFIG_KALLSYMS_ALL
2214 || !(sec->sh_flags & SHF_EXECINSTR)
2215#endif
2216 || (sec->sh_entsize & INIT_OFFSET_MASK))
2217 return false;
2218
2219 return true;
2220}
2221
2222/*
2223 * We only allocate and copy the strings needed by the parts of symtab
2224 * we keep. This is simple, but has the effect of making multiple
2225 * copies of duplicates. We could be more sophisticated, see
2226 * linux-kernel thread starting with
2227 * <73defb5e4bca04a6431392cc341112b1@localhost>.
2228 */
2229static void layout_symtab(struct module *mod, struct load_info *info)
2230{
2231 Elf_Shdr *symsect = info->sechdrs + info->index.sym;
2232 Elf_Shdr *strsect = info->sechdrs + info->index.str;
2233 const Elf_Sym *src;
2234 unsigned int i, nsrc, ndst, strtab_size;
2235
2236 /* Put symbol section at end of init part of module. */
2237 symsect->sh_flags |= SHF_ALLOC;
2238 symsect->sh_entsize = get_offset(mod, &mod->init_size, symsect,
2239 info->index.sym) | INIT_OFFSET_MASK;
2240 pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
2241
2242 src = (void *)info->hdr + symsect->sh_offset;
2243 nsrc = symsect->sh_size / sizeof(*src);
2244
2245 /* Compute total space required for the core symbols' strtab. */
2246 for (ndst = i = strtab_size = 1; i < nsrc; ++i, ++src)
2247 if (is_core_symbol(src, info->sechdrs, info->hdr->e_shnum)) {
2248 strtab_size += strlen(&info->strtab[src->st_name]) + 1;
2249 ndst++;
2250 }
2251
2252 /* Append room for core symbols at end of core part. */
2253 info->symoffs = ALIGN(mod->core_size, symsect->sh_addralign ?: 1);
2254 info->stroffs = mod->core_size = info->symoffs + ndst * sizeof(Elf_Sym);
2255 mod->core_size += strtab_size;
2256
2257 /* Put string table section at end of init part of module. */
2258 strsect->sh_flags |= SHF_ALLOC;
2259 strsect->sh_entsize = get_offset(mod, &mod->init_size, strsect,
2260 info->index.str) | INIT_OFFSET_MASK;
2261 pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
2262}
2263
2264static void add_kallsyms(struct module *mod, const struct load_info *info)
2265{
2266 unsigned int i, ndst;
2267 const Elf_Sym *src;
2268 Elf_Sym *dst;
2269 char *s;
2270 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2271
2272 mod->symtab = (void *)symsec->sh_addr;
2273 mod->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
2274 /* Make sure we get permanent strtab: don't use info->strtab. */
2275 mod->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
2276
2277 /* Set types up while we still have access to sections. */
2278 for (i = 0; i < mod->num_symtab; i++)
2279 mod->symtab[i].st_info = elf_type(&mod->symtab[i], info);
2280
2281 mod->core_symtab = dst = mod->module_core + info->symoffs;
2282 mod->core_strtab = s = mod->module_core + info->stroffs;
2283 src = mod->symtab;
2284 *dst = *src;
2285 *s++ = 0;
2286 for (ndst = i = 1; i < mod->num_symtab; ++i, ++src) {
2287 if (!is_core_symbol(src, info->sechdrs, info->hdr->e_shnum))
2288 continue;
2289
2290 dst[ndst] = *src;
2291 dst[ndst++].st_name = s - mod->core_strtab;
2292 s += strlcpy(s, &mod->strtab[src->st_name], KSYM_NAME_LEN) + 1;
2293 }
2294 mod->core_num_syms = ndst;
2295}
2296#else
2297static inline void layout_symtab(struct module *mod, struct load_info *info)
2298{
2299}
2300
2301static void add_kallsyms(struct module *mod, const struct load_info *info)
2302{
2303}
2304#endif /* CONFIG_KALLSYMS */
2305
2306static void dynamic_debug_setup(struct _ddebug *debug, unsigned int num)
2307{
2308 if (!debug)
2309 return;
2310#ifdef CONFIG_DYNAMIC_DEBUG
2311 if (ddebug_add_module(debug, num, debug->modname))
2312 printk(KERN_ERR "dynamic debug error adding module: %s\n",
2313 debug->modname);
2314#endif
2315}
2316
2317static void dynamic_debug_remove(struct _ddebug *debug)
2318{
2319 if (debug)
2320 ddebug_remove_module(debug->modname);
2321}
2322
2323void * __weak module_alloc(unsigned long size)
2324{
2325 return size == 0 ? NULL : vmalloc_exec(size);
2326}
2327
2328static void *module_alloc_update_bounds(unsigned long size)
2329{
2330 void *ret = module_alloc(size);
2331
2332 if (ret) {
2333 mutex_lock(&module_mutex);
2334 /* Update module bounds. */
2335 if ((unsigned long)ret < module_addr_min)
2336 module_addr_min = (unsigned long)ret;
2337 if ((unsigned long)ret + size > module_addr_max)
2338 module_addr_max = (unsigned long)ret + size;
2339 mutex_unlock(&module_mutex);
2340 }
2341 return ret;
2342}
2343
2344#ifdef CONFIG_DEBUG_KMEMLEAK
2345static void kmemleak_load_module(const struct module *mod,
2346 const struct load_info *info)
2347{
2348 unsigned int i;
2349
2350 /* only scan the sections containing data */
2351 kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
2352
2353 for (i = 1; i < info->hdr->e_shnum; i++) {
2354 const char *name = info->secstrings + info->sechdrs[i].sh_name;
2355 if (!(info->sechdrs[i].sh_flags & SHF_ALLOC))
2356 continue;
2357 if (!strstarts(name, ".data") && !strstarts(name, ".bss"))
2358 continue;
2359
2360 kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
2361 info->sechdrs[i].sh_size, GFP_KERNEL);
2362 }
2363}
2364#else
2365static inline void kmemleak_load_module(const struct module *mod,
2366 const struct load_info *info)
2367{
2368}
2369#endif
2370
2371/* Sets info->hdr and info->len. */
2372static int copy_and_check(struct load_info *info,
2373 const void __user *umod, unsigned long len,
2374 const char __user *uargs)
2375{
2376 int err;
2377 Elf_Ehdr *hdr;
2378
2379 if (len < sizeof(*hdr))
2380 return -ENOEXEC;
2381
2382 /* Suck in entire file: we'll want most of it. */
2383 /* vmalloc barfs on "unusual" numbers. Check here */
2384 if (len > 64 * 1024 * 1024 || (hdr = vmalloc(len)) == NULL)
2385 return -ENOMEM;
2386
2387 if (copy_from_user(hdr, umod, len) != 0) {
2388 err = -EFAULT;
2389 goto free_hdr;
2390 }
2391
2392 /* Sanity checks against insmoding binaries or wrong arch,
2393 weird elf version */
2394 if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0
2395 || hdr->e_type != ET_REL
2396 || !elf_check_arch(hdr)
2397 || hdr->e_shentsize != sizeof(Elf_Shdr)) {
2398 err = -ENOEXEC;
2399 goto free_hdr;
2400 }
2401
2402 if (len < hdr->e_shoff + hdr->e_shnum * sizeof(Elf_Shdr)) {
2403 err = -ENOEXEC;
2404 goto free_hdr;
2405 }
2406
2407 info->hdr = hdr;
2408 info->len = len;
2409 return 0;
2410
2411free_hdr:
2412 vfree(hdr);
2413 return err;
2414}
2415
2416static void free_copy(struct load_info *info)
2417{
2418 vfree(info->hdr);
2419}
2420
2421static int rewrite_section_headers(struct load_info *info)
2422{
2423 unsigned int i;
2424
2425 /* This should always be true, but let's be sure. */
2426 info->sechdrs[0].sh_addr = 0;
2427
2428 for (i = 1; i < info->hdr->e_shnum; i++) {
2429 Elf_Shdr *shdr = &info->sechdrs[i];
2430 if (shdr->sh_type != SHT_NOBITS
2431 && info->len < shdr->sh_offset + shdr->sh_size) {
2432 printk(KERN_ERR "Module len %lu truncated\n",
2433 info->len);
2434 return -ENOEXEC;
2435 }
2436
2437 /* Mark all sections sh_addr with their address in the
2438 temporary image. */
2439 shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
2440
2441#ifndef CONFIG_MODULE_UNLOAD
2442 /* Don't load .exit sections */
2443 if (strstarts(info->secstrings+shdr->sh_name, ".exit"))
2444 shdr->sh_flags &= ~(unsigned long)SHF_ALLOC;
2445#endif
2446 }
2447
2448 /* Track but don't keep modinfo and version sections. */
2449 info->index.vers = find_sec(info, "__versions");
2450 info->index.info = find_sec(info, ".modinfo");
2451 info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
2452 info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
2453 return 0;
2454}
2455
2456/*
2457 * Set up our basic convenience variables (pointers to section headers,
2458 * search for module section index etc), and do some basic section
2459 * verification.
2460 *
2461 * Return the temporary module pointer (we'll replace it with the final
2462 * one when we move the module sections around).
2463 */
2464static struct module *setup_load_info(struct load_info *info)
2465{
2466 unsigned int i;
2467 int err;
2468 struct module *mod;
2469
2470 /* Set up the convenience variables */
2471 info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
2472 info->secstrings = (void *)info->hdr
2473 + info->sechdrs[info->hdr->e_shstrndx].sh_offset;
2474
2475 err = rewrite_section_headers(info);
2476 if (err)
2477 return ERR_PTR(err);
2478
2479 /* Find internal symbols and strings. */
2480 for (i = 1; i < info->hdr->e_shnum; i++) {
2481 if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
2482 info->index.sym = i;
2483 info->index.str = info->sechdrs[i].sh_link;
2484 info->strtab = (char *)info->hdr
2485 + info->sechdrs[info->index.str].sh_offset;
2486 break;
2487 }
2488 }
2489
2490 info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
2491 if (!info->index.mod) {
2492 printk(KERN_WARNING "No module found in object\n");
2493 return ERR_PTR(-ENOEXEC);
2494 }
2495 /* This is temporary: point mod into copy of data. */
2496 mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2497
2498 if (info->index.sym == 0) {
2499 printk(KERN_WARNING "%s: module has no symbols (stripped?)\n",
2500 mod->name);
2501 return ERR_PTR(-ENOEXEC);
2502 }
2503
2504 info->index.pcpu = find_pcpusec(info);
2505
2506 /* Check module struct version now, before we try to use module. */
2507 if (!check_modstruct_version(info->sechdrs, info->index.vers, mod))
2508 return ERR_PTR(-ENOEXEC);
2509
2510 return mod;
2511}
2512
2513static int check_modinfo(struct module *mod, struct load_info *info)
2514{
2515 const char *modmagic = get_modinfo(info, "vermagic");
2516 int err;
2517
2518 /* This is allowed: modprobe --force will invalidate it. */
2519 if (!modmagic) {
2520 err = try_to_force_load(mod, "bad vermagic");
2521 if (err)
2522 return err;
2523 } else if (!same_magic(modmagic, vermagic, info->index.vers)) {
2524 printk(KERN_ERR "%s: version magic '%s' should be '%s'\n",
2525 mod->name, modmagic, vermagic);
2526 return -ENOEXEC;
2527 }
2528
2529 if (!get_modinfo(info, "intree"))
2530 add_taint_module(mod, TAINT_OOT_MODULE);
2531
2532 if (get_modinfo(info, "staging")) {
2533 add_taint_module(mod, TAINT_CRAP);
2534 printk(KERN_WARNING "%s: module is from the staging directory,"
2535 " the quality is unknown, you have been warned.\n",
2536 mod->name);
2537 }
2538
2539 /* Set up license info based on the info section */
2540 set_license(mod, get_modinfo(info, "license"));
2541
2542 return 0;
2543}
2544
2545static void find_module_sections(struct module *mod, struct load_info *info)
2546{
2547 mod->kp = section_objs(info, "__param",
2548 sizeof(*mod->kp), &mod->num_kp);
2549 mod->syms = section_objs(info, "__ksymtab",
2550 sizeof(*mod->syms), &mod->num_syms);
2551 mod->crcs = section_addr(info, "__kcrctab");
2552 mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
2553 sizeof(*mod->gpl_syms),
2554 &mod->num_gpl_syms);
2555 mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
2556 mod->gpl_future_syms = section_objs(info,
2557 "__ksymtab_gpl_future",
2558 sizeof(*mod->gpl_future_syms),
2559 &mod->num_gpl_future_syms);
2560 mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future");
2561
2562#ifdef CONFIG_UNUSED_SYMBOLS
2563 mod->unused_syms = section_objs(info, "__ksymtab_unused",
2564 sizeof(*mod->unused_syms),
2565 &mod->num_unused_syms);
2566 mod->unused_crcs = section_addr(info, "__kcrctab_unused");
2567 mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl",
2568 sizeof(*mod->unused_gpl_syms),
2569 &mod->num_unused_gpl_syms);
2570 mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl");
2571#endif
2572#ifdef CONFIG_CONSTRUCTORS
2573 mod->ctors = section_objs(info, ".ctors",
2574 sizeof(*mod->ctors), &mod->num_ctors);
2575#endif
2576
2577#ifdef CONFIG_TRACEPOINTS
2578 mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
2579 sizeof(*mod->tracepoints_ptrs),
2580 &mod->num_tracepoints);
2581#endif
2582#ifdef HAVE_JUMP_LABEL
2583 mod->jump_entries = section_objs(info, "__jump_table",
2584 sizeof(*mod->jump_entries),
2585 &mod->num_jump_entries);
2586#endif
2587#ifdef CONFIG_EVENT_TRACING
2588 mod->trace_events = section_objs(info, "_ftrace_events",
2589 sizeof(*mod->trace_events),
2590 &mod->num_trace_events);
2591 /*
2592 * This section contains pointers to allocated objects in the trace
2593 * code and not scanning it leads to false positives.
2594 */
2595 kmemleak_scan_area(mod->trace_events, sizeof(*mod->trace_events) *
2596 mod->num_trace_events, GFP_KERNEL);
2597#endif
2598#ifdef CONFIG_TRACING
2599 mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
2600 sizeof(*mod->trace_bprintk_fmt_start),
2601 &mod->num_trace_bprintk_fmt);
2602 /*
2603 * This section contains pointers to allocated objects in the trace
2604 * code and not scanning it leads to false positives.
2605 */
2606 kmemleak_scan_area(mod->trace_bprintk_fmt_start,
2607 sizeof(*mod->trace_bprintk_fmt_start) *
2608 mod->num_trace_bprintk_fmt, GFP_KERNEL);
2609#endif
2610#ifdef CONFIG_FTRACE_MCOUNT_RECORD
2611 /* sechdrs[0].sh_size is always zero */
2612 mod->ftrace_callsites = section_objs(info, "__mcount_loc",
2613 sizeof(*mod->ftrace_callsites),
2614 &mod->num_ftrace_callsites);
2615#endif
2616
2617 mod->extable = section_objs(info, "__ex_table",
2618 sizeof(*mod->extable), &mod->num_exentries);
2619
2620 if (section_addr(info, "__obsparm"))
2621 printk(KERN_WARNING "%s: Ignoring obsolete parameters\n",
2622 mod->name);
2623
2624 info->debug = section_objs(info, "__verbose",
2625 sizeof(*info->debug), &info->num_debug);
2626}
2627
2628static int move_module(struct module *mod, struct load_info *info)
2629{
2630 int i;
2631 void *ptr;
2632
2633 /* Do the allocs. */
2634 ptr = module_alloc_update_bounds(mod->core_size);
2635 /*
2636 * The pointer to this block is stored in the module structure
2637 * which is inside the block. Just mark it as not being a
2638 * leak.
2639 */
2640 kmemleak_not_leak(ptr);
2641 if (!ptr)
2642 return -ENOMEM;
2643
2644 memset(ptr, 0, mod->core_size);
2645 mod->module_core = ptr;
2646
2647 ptr = module_alloc_update_bounds(mod->init_size);
2648 /*
2649 * The pointer to this block is stored in the module structure
2650 * which is inside the block. This block doesn't need to be
2651 * scanned as it contains data and code that will be freed
2652 * after the module is initialized.
2653 */
2654 kmemleak_ignore(ptr);
2655 if (!ptr && mod->init_size) {
2656 module_free(mod, mod->module_core);
2657 return -ENOMEM;
2658 }
2659 memset(ptr, 0, mod->init_size);
2660 mod->module_init = ptr;
2661
2662 /* Transfer each section which specifies SHF_ALLOC */
2663 pr_debug("final section addresses:\n");
2664 for (i = 0; i < info->hdr->e_shnum; i++) {
2665 void *dest;
2666 Elf_Shdr *shdr = &info->sechdrs[i];
2667
2668 if (!(shdr->sh_flags & SHF_ALLOC))
2669 continue;
2670
2671 if (shdr->sh_entsize & INIT_OFFSET_MASK)
2672 dest = mod->module_init
2673 + (shdr->sh_entsize & ~INIT_OFFSET_MASK);
2674 else
2675 dest = mod->module_core + shdr->sh_entsize;
2676
2677 if (shdr->sh_type != SHT_NOBITS)
2678 memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
2679 /* Update sh_addr to point to copy in image. */
2680 shdr->sh_addr = (unsigned long)dest;
2681 pr_debug("\t0x%lx %s\n",
2682 (long)shdr->sh_addr, info->secstrings + shdr->sh_name);
2683 }
2684
2685 return 0;
2686}
2687
2688static int check_module_license_and_versions(struct module *mod)
2689{
2690 /*
2691 * ndiswrapper is under GPL by itself, but loads proprietary modules.
2692 * Don't use add_taint_module(), as it would prevent ndiswrapper from
2693 * using GPL-only symbols it needs.
2694 */
2695 if (strcmp(mod->name, "ndiswrapper") == 0)
2696 add_taint(TAINT_PROPRIETARY_MODULE);
2697
2698 /* driverloader was caught wrongly pretending to be under GPL */
2699 if (strcmp(mod->name, "driverloader") == 0)
2700 add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
2701
2702#ifdef CONFIG_MODVERSIONS
2703 if ((mod->num_syms && !mod->crcs)
2704 || (mod->num_gpl_syms && !mod->gpl_crcs)
2705 || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
2706#ifdef CONFIG_UNUSED_SYMBOLS
2707 || (mod->num_unused_syms && !mod->unused_crcs)
2708 || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
2709#endif
2710 ) {
2711 return try_to_force_load(mod,
2712 "no versions for exported symbols");
2713 }
2714#endif
2715 return 0;
2716}
2717
2718static void flush_module_icache(const struct module *mod)
2719{
2720 mm_segment_t old_fs;
2721
2722 /* flush the icache in correct context */
2723 old_fs = get_fs();
2724 set_fs(KERNEL_DS);
2725
2726 /*
2727 * Flush the instruction cache, since we've played with text.
2728 * Do it before processing of module parameters, so the module
2729 * can provide parameter accessor functions of its own.
2730 */
2731 if (mod->module_init)
2732 flush_icache_range((unsigned long)mod->module_init,
2733 (unsigned long)mod->module_init
2734 + mod->init_size);
2735 flush_icache_range((unsigned long)mod->module_core,
2736 (unsigned long)mod->module_core + mod->core_size);
2737
2738 set_fs(old_fs);
2739}
2740
2741int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
2742 Elf_Shdr *sechdrs,
2743 char *secstrings,
2744 struct module *mod)
2745{
2746 return 0;
2747}
2748
2749static struct module *layout_and_allocate(struct load_info *info)
2750{
2751 /* Module within temporary copy. */
2752 struct module *mod;
2753 Elf_Shdr *pcpusec;
2754 int err;
2755
2756 mod = setup_load_info(info);
2757 if (IS_ERR(mod))
2758 return mod;
2759
2760 err = check_modinfo(mod, info);
2761 if (err)
2762 return ERR_PTR(err);
2763
2764 /* Allow arches to frob section contents and sizes. */
2765 err = module_frob_arch_sections(info->hdr, info->sechdrs,
2766 info->secstrings, mod);
2767 if (err < 0)
2768 goto out;
2769
2770 pcpusec = &info->sechdrs[info->index.pcpu];
2771 if (pcpusec->sh_size) {
2772 /* We have a special allocation for this section. */
2773 err = percpu_modalloc(mod,
2774 pcpusec->sh_size, pcpusec->sh_addralign);
2775 if (err)
2776 goto out;
2777 pcpusec->sh_flags &= ~(unsigned long)SHF_ALLOC;
2778 }
2779
2780 /* Determine total sizes, and put offsets in sh_entsize. For now
2781 this is done generically; there doesn't appear to be any
2782 special cases for the architectures. */
2783 layout_sections(mod, info);
2784 layout_symtab(mod, info);
2785
2786 /* Allocate and move to the final place */
2787 err = move_module(mod, info);
2788 if (err)
2789 goto free_percpu;
2790
2791 /* Module has been copied to its final place now: return it. */
2792 mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2793 kmemleak_load_module(mod, info);
2794 return mod;
2795
2796free_percpu:
2797 percpu_modfree(mod);
2798out:
2799 return ERR_PTR(err);
2800}
2801
2802/* mod is no longer valid after this! */
2803static void module_deallocate(struct module *mod, struct load_info *info)
2804{
2805 percpu_modfree(mod);
2806 module_free(mod, mod->module_init);
2807 module_free(mod, mod->module_core);
2808}
2809
2810int __weak module_finalize(const Elf_Ehdr *hdr,
2811 const Elf_Shdr *sechdrs,
2812 struct module *me)
2813{
2814 return 0;
2815}
2816
2817static int post_relocation(struct module *mod, const struct load_info *info)
2818{
2819 /* Sort exception table now relocations are done. */
2820 sort_extable(mod->extable, mod->extable + mod->num_exentries);
2821
2822 /* Copy relocated percpu area over. */
2823 percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
2824 info->sechdrs[info->index.pcpu].sh_size);
2825
2826 /* Setup kallsyms-specific fields. */
2827 add_kallsyms(mod, info);
2828
2829 /* Arch-specific module finalizing. */
2830 return module_finalize(info->hdr, info->sechdrs, mod);
2831}
2832
2833/* Allocate and load the module: note that size of section 0 is always
2834 zero, and we rely on this for optional sections. */
2835static struct module *load_module(void __user *umod,
2836 unsigned long len,
2837 const char __user *uargs)
2838{
2839 struct load_info info = { NULL, };
2840 struct module *mod;
2841 long err;
2842
2843 pr_debug("load_module: umod=%p, len=%lu, uargs=%p\n",
2844 umod, len, uargs);
2845
2846 /* Copy in the blobs from userspace, check they are vaguely sane. */
2847 err = copy_and_check(&info, umod, len, uargs);
2848 if (err)
2849 return ERR_PTR(err);
2850
2851 /* Figure out module layout, and allocate all the memory. */
2852 mod = layout_and_allocate(&info);
2853 if (IS_ERR(mod)) {
2854 err = PTR_ERR(mod);
2855 goto free_copy;
2856 }
2857
2858 /* Now module is in final location, initialize linked lists, etc. */
2859 err = module_unload_init(mod);
2860 if (err)
2861 goto free_module;
2862
2863 /* Now we've got everything in the final locations, we can
2864 * find optional sections. */
2865 find_module_sections(mod, &info);
2866
2867 err = check_module_license_and_versions(mod);
2868 if (err)
2869 goto free_unload;
2870
2871 /* Set up MODINFO_ATTR fields */
2872 setup_modinfo(mod, &info);
2873
2874 /* Fix up syms, so that st_value is a pointer to location. */
2875 err = simplify_symbols(mod, &info);
2876 if (err < 0)
2877 goto free_modinfo;
2878
2879 err = apply_relocations(mod, &info);
2880 if (err < 0)
2881 goto free_modinfo;
2882
2883 err = post_relocation(mod, &info);
2884 if (err < 0)
2885 goto free_modinfo;
2886
2887 flush_module_icache(mod);
2888
2889 /* Now copy in args */
2890 mod->args = strndup_user(uargs, ~0UL >> 1);
2891 if (IS_ERR(mod->args)) {
2892 err = PTR_ERR(mod->args);
2893 goto free_arch_cleanup;
2894 }
2895
2896 /* Mark state as coming so strong_try_module_get() ignores us. */
2897 mod->state = MODULE_STATE_COMING;
2898
2899 /* Now sew it into the lists so we can get lockdep and oops
2900 * info during argument parsing. No one should access us, since
2901 * strong_try_module_get() will fail.
2902 * lockdep/oops can run asynchronous, so use the RCU list insertion
2903 * function to insert in a way safe to concurrent readers.
2904 * The mutex protects against concurrent writers.
2905 */
2906 mutex_lock(&module_mutex);
2907 if (find_module(mod->name)) {
2908 err = -EEXIST;
2909 goto unlock;
2910 }
2911
2912 /* This has to be done once we're sure module name is unique. */
2913 dynamic_debug_setup(info.debug, info.num_debug);
2914
2915 /* Find duplicate symbols */
2916 err = verify_export_symbols(mod);
2917 if (err < 0)
2918 goto ddebug;
2919
2920 module_bug_finalize(info.hdr, info.sechdrs, mod);
2921 list_add_rcu(&mod->list, &modules);
2922 mutex_unlock(&module_mutex);
2923
2924 /* Module is ready to execute: parsing args may do that. */
2925 err = parse_args(mod->name, mod->args, mod->kp, mod->num_kp, NULL);
2926 if (err < 0)
2927 goto unlink;
2928
2929 /* Link in to syfs. */
2930 err = mod_sysfs_setup(mod, &info, mod->kp, mod->num_kp);
2931 if (err < 0)
2932 goto unlink;
2933
2934 /* Get rid of temporary copy. */
2935 free_copy(&info);
2936
2937 /* Done! */
2938 trace_module_load(mod);
2939 return mod;
2940
2941 unlink:
2942 mutex_lock(&module_mutex);
2943 /* Unlink carefully: kallsyms could be walking list. */
2944 list_del_rcu(&mod->list);
2945 module_bug_cleanup(mod);
2946
2947 ddebug:
2948 dynamic_debug_remove(info.debug);
2949 unlock:
2950 mutex_unlock(&module_mutex);
2951 synchronize_sched();
2952 kfree(mod->args);
2953 free_arch_cleanup:
2954 module_arch_cleanup(mod);
2955 free_modinfo:
2956 free_modinfo(mod);
2957 free_unload:
2958 module_unload_free(mod);
2959 free_module:
2960 module_deallocate(mod, &info);
2961 free_copy:
2962 free_copy(&info);
2963 return ERR_PTR(err);
2964}
2965
2966/* Call module constructors. */
2967static void do_mod_ctors(struct module *mod)
2968{
2969#ifdef CONFIG_CONSTRUCTORS
2970 unsigned long i;
2971
2972 for (i = 0; i < mod->num_ctors; i++)
2973 mod->ctors[i]();
2974#endif
2975}
2976
2977/* This is where the real work happens */
2978SYSCALL_DEFINE3(init_module, void __user *, umod,
2979 unsigned long, len, const char __user *, uargs)
2980{
2981 struct module *mod;
2982 int ret = 0;
2983
2984 /* Must have permission */
2985 if (!capable(CAP_SYS_MODULE) || modules_disabled)
2986 return -EPERM;
2987
2988 /* Do all the hard work */
2989 mod = load_module(umod, len, uargs);
2990 if (IS_ERR(mod))
2991 return PTR_ERR(mod);
2992
2993 blocking_notifier_call_chain(&module_notify_list,
2994 MODULE_STATE_COMING, mod);
2995
2996 /* Set RO and NX regions for core */
2997 set_section_ro_nx(mod->module_core,
2998 mod->core_text_size,
2999 mod->core_ro_size,
3000 mod->core_size);
3001
3002 /* Set RO and NX regions for init */
3003 set_section_ro_nx(mod->module_init,
3004 mod->init_text_size,
3005 mod->init_ro_size,
3006 mod->init_size);
3007
3008 do_mod_ctors(mod);
3009 /* Start the module */
3010 if (mod->init != NULL)
3011 ret = do_one_initcall(mod->init);
3012 if (ret < 0) {
3013 /* Init routine failed: abort. Try to protect us from
3014 buggy refcounters. */
3015 mod->state = MODULE_STATE_GOING;
3016 synchronize_sched();
3017 module_put(mod);
3018 blocking_notifier_call_chain(&module_notify_list,
3019 MODULE_STATE_GOING, mod);
3020 free_module(mod);
3021 wake_up(&module_wq);
3022 return ret;
3023 }
3024 if (ret > 0) {
3025 printk(KERN_WARNING
3026"%s: '%s'->init suspiciously returned %d, it should follow 0/-E convention\n"
3027"%s: loading module anyway...\n",
3028 __func__, mod->name, ret,
3029 __func__);
3030 dump_stack();
3031 }
3032
3033 /* Now it's a first class citizen! Wake up anyone waiting for it. */
3034 mod->state = MODULE_STATE_LIVE;
3035 wake_up(&module_wq);
3036 blocking_notifier_call_chain(&module_notify_list,
3037 MODULE_STATE_LIVE, mod);
3038
3039 /* We need to finish all async code before the module init sequence is done */
3040 async_synchronize_full();
3041
3042 mutex_lock(&module_mutex);
3043 /* Drop initial reference. */
3044 module_put(mod);
3045 trim_init_extable(mod);
3046#ifdef CONFIG_KALLSYMS
3047 mod->num_symtab = mod->core_num_syms;
3048 mod->symtab = mod->core_symtab;
3049 mod->strtab = mod->core_strtab;
3050#endif
3051 unset_module_init_ro_nx(mod);
3052 module_free(mod, mod->module_init);
3053 mod->module_init = NULL;
3054 mod->init_size = 0;
3055 mod->init_ro_size = 0;
3056 mod->init_text_size = 0;
3057 mutex_unlock(&module_mutex);
3058
3059 return 0;
3060}
3061
3062static inline int within(unsigned long addr, void *start, unsigned long size)
3063{
3064 return ((void *)addr >= start && (void *)addr < start + size);
3065}
3066
3067#ifdef CONFIG_KALLSYMS
3068/*
3069 * This ignores the intensely annoying "mapping symbols" found
3070 * in ARM ELF files: $a, $t and $d.
3071 */
3072static inline int is_arm_mapping_symbol(const char *str)
3073{
3074 return str[0] == '$' && strchr("atd", str[1])
3075 && (str[2] == '\0' || str[2] == '.');
3076}
3077
3078static const char *get_ksymbol(struct module *mod,
3079 unsigned long addr,
3080 unsigned long *size,
3081 unsigned long *offset)
3082{
3083 unsigned int i, best = 0;
3084 unsigned long nextval;
3085
3086 /* At worse, next value is at end of module */
3087 if (within_module_init(addr, mod))
3088 nextval = (unsigned long)mod->module_init+mod->init_text_size;
3089 else
3090 nextval = (unsigned long)mod->module_core+mod->core_text_size;
3091
3092 /* Scan for closest preceding symbol, and next symbol. (ELF
3093 starts real symbols at 1). */
3094 for (i = 1; i < mod->num_symtab; i++) {
3095 if (mod->symtab[i].st_shndx == SHN_UNDEF)
3096 continue;
3097
3098 /* We ignore unnamed symbols: they're uninformative
3099 * and inserted at a whim. */
3100 if (mod->symtab[i].st_value <= addr
3101 && mod->symtab[i].st_value > mod->symtab[best].st_value
3102 && *(mod->strtab + mod->symtab[i].st_name) != '\0'
3103 && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
3104 best = i;
3105 if (mod->symtab[i].st_value > addr
3106 && mod->symtab[i].st_value < nextval
3107 && *(mod->strtab + mod->symtab[i].st_name) != '\0'
3108 && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
3109 nextval = mod->symtab[i].st_value;
3110 }
3111
3112 if (!best)
3113 return NULL;
3114
3115 if (size)
3116 *size = nextval - mod->symtab[best].st_value;
3117 if (offset)
3118 *offset = addr - mod->symtab[best].st_value;
3119 return mod->strtab + mod->symtab[best].st_name;
3120}
3121
3122/* For kallsyms to ask for address resolution. NULL means not found. Careful
3123 * not to lock to avoid deadlock on oopses, simply disable preemption. */
3124const char *module_address_lookup(unsigned long addr,
3125 unsigned long *size,
3126 unsigned long *offset,
3127 char **modname,
3128 char *namebuf)
3129{
3130 struct module *mod;
3131 const char *ret = NULL;
3132
3133 preempt_disable();
3134 list_for_each_entry_rcu(mod, &modules, list) {
3135 if (within_module_init(addr, mod) ||
3136 within_module_core(addr, mod)) {
3137 if (modname)
3138 *modname = mod->name;
3139 ret = get_ksymbol(mod, addr, size, offset);
3140 break;
3141 }
3142 }
3143 /* Make a copy in here where it's safe */
3144 if (ret) {
3145 strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
3146 ret = namebuf;
3147 }
3148 preempt_enable();
3149 return ret;
3150}
3151
3152int lookup_module_symbol_name(unsigned long addr, char *symname)
3153{
3154 struct module *mod;
3155
3156 preempt_disable();
3157 list_for_each_entry_rcu(mod, &modules, list) {
3158 if (within_module_init(addr, mod) ||
3159 within_module_core(addr, mod)) {
3160 const char *sym;
3161
3162 sym = get_ksymbol(mod, addr, NULL, NULL);
3163 if (!sym)
3164 goto out;
3165 strlcpy(symname, sym, KSYM_NAME_LEN);
3166 preempt_enable();
3167 return 0;
3168 }
3169 }
3170out:
3171 preempt_enable();
3172 return -ERANGE;
3173}
3174
3175int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
3176 unsigned long *offset, char *modname, char *name)
3177{
3178 struct module *mod;
3179
3180 preempt_disable();
3181 list_for_each_entry_rcu(mod, &modules, list) {
3182 if (within_module_init(addr, mod) ||
3183 within_module_core(addr, mod)) {
3184 const char *sym;
3185
3186 sym = get_ksymbol(mod, addr, size, offset);
3187 if (!sym)
3188 goto out;
3189 if (modname)
3190 strlcpy(modname, mod->name, MODULE_NAME_LEN);
3191 if (name)
3192 strlcpy(name, sym, KSYM_NAME_LEN);
3193 preempt_enable();
3194 return 0;
3195 }
3196 }
3197out:
3198 preempt_enable();
3199 return -ERANGE;
3200}
3201
3202int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
3203 char *name, char *module_name, int *exported)
3204{
3205 struct module *mod;
3206
3207 preempt_disable();
3208 list_for_each_entry_rcu(mod, &modules, list) {
3209 if (symnum < mod->num_symtab) {
3210 *value = mod->symtab[symnum].st_value;
3211 *type = mod->symtab[symnum].st_info;
3212 strlcpy(name, mod->strtab + mod->symtab[symnum].st_name,
3213 KSYM_NAME_LEN);
3214 strlcpy(module_name, mod->name, MODULE_NAME_LEN);
3215 *exported = is_exported(name, *value, mod);
3216 preempt_enable();
3217 return 0;
3218 }
3219 symnum -= mod->num_symtab;
3220 }
3221 preempt_enable();
3222 return -ERANGE;
3223}
3224
3225static unsigned long mod_find_symname(struct module *mod, const char *name)
3226{
3227 unsigned int i;
3228
3229 for (i = 0; i < mod->num_symtab; i++)
3230 if (strcmp(name, mod->strtab+mod->symtab[i].st_name) == 0 &&
3231 mod->symtab[i].st_info != 'U')
3232 return mod->symtab[i].st_value;
3233 return 0;
3234}
3235
3236/* Look for this name: can be of form module:name. */
3237unsigned long module_kallsyms_lookup_name(const char *name)
3238{
3239 struct module *mod;
3240 char *colon;
3241 unsigned long ret = 0;
3242
3243 /* Don't lock: we're in enough trouble already. */
3244 preempt_disable();
3245 if ((colon = strchr(name, ':')) != NULL) {
3246 *colon = '\0';
3247 if ((mod = find_module(name)) != NULL)
3248 ret = mod_find_symname(mod, colon+1);
3249 *colon = ':';
3250 } else {
3251 list_for_each_entry_rcu(mod, &modules, list)
3252 if ((ret = mod_find_symname(mod, name)) != 0)
3253 break;
3254 }
3255 preempt_enable();
3256 return ret;
3257}
3258
3259int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
3260 struct module *, unsigned long),
3261 void *data)
3262{
3263 struct module *mod;
3264 unsigned int i;
3265 int ret;
3266
3267 list_for_each_entry(mod, &modules, list) {
3268 for (i = 0; i < mod->num_symtab; i++) {
3269 ret = fn(data, mod->strtab + mod->symtab[i].st_name,
3270 mod, mod->symtab[i].st_value);
3271 if (ret != 0)
3272 return ret;
3273 }
3274 }
3275 return 0;
3276}
3277#endif /* CONFIG_KALLSYMS */
3278
3279static char *module_flags(struct module *mod, char *buf)
3280{
3281 int bx = 0;
3282
3283 if (mod->taints ||
3284 mod->state == MODULE_STATE_GOING ||
3285 mod->state == MODULE_STATE_COMING) {
3286 buf[bx++] = '(';
3287 bx += module_flags_taint(mod, buf + bx);
3288 /* Show a - for module-is-being-unloaded */
3289 if (mod->state == MODULE_STATE_GOING)
3290 buf[bx++] = '-';
3291 /* Show a + for module-is-being-loaded */
3292 if (mod->state == MODULE_STATE_COMING)
3293 buf[bx++] = '+';
3294 buf[bx++] = ')';
3295 }
3296 buf[bx] = '\0';
3297
3298 return buf;
3299}
3300
3301#ifdef CONFIG_PROC_FS
3302/* Called by the /proc file system to return a list of modules. */
3303static void *m_start(struct seq_file *m, loff_t *pos)
3304{
3305 mutex_lock(&module_mutex);
3306 return seq_list_start(&modules, *pos);
3307}
3308
3309static void *m_next(struct seq_file *m, void *p, loff_t *pos)
3310{
3311 return seq_list_next(p, &modules, pos);
3312}
3313
3314static void m_stop(struct seq_file *m, void *p)
3315{
3316 mutex_unlock(&module_mutex);
3317}
3318
3319static int m_show(struct seq_file *m, void *p)
3320{
3321 struct module *mod = list_entry(p, struct module, list);
3322 char buf[8];
3323
3324 seq_printf(m, "%s %u",
3325 mod->name, mod->init_size + mod->core_size);
3326 print_unload_info(m, mod);
3327
3328 /* Informative for users. */
3329 seq_printf(m, " %s",
3330 mod->state == MODULE_STATE_GOING ? "Unloading":
3331 mod->state == MODULE_STATE_COMING ? "Loading":
3332 "Live");
3333 /* Used by oprofile and other similar tools. */
3334 seq_printf(m, " 0x%pK", mod->module_core);
3335
3336 /* Taints info */
3337 if (mod->taints)
3338 seq_printf(m, " %s", module_flags(mod, buf));
3339
3340 seq_printf(m, "\n");
3341 return 0;
3342}
3343
3344/* Format: modulename size refcount deps address
3345
3346 Where refcount is a number or -, and deps is a comma-separated list
3347 of depends or -.
3348*/
3349static const struct seq_operations modules_op = {
3350 .start = m_start,
3351 .next = m_next,
3352 .stop = m_stop,
3353 .show = m_show
3354};
3355
3356static int modules_open(struct inode *inode, struct file *file)
3357{
3358 return seq_open(file, &modules_op);
3359}
3360
3361static const struct file_operations proc_modules_operations = {
3362 .open = modules_open,
3363 .read = seq_read,
3364 .llseek = seq_lseek,
3365 .release = seq_release,
3366};
3367
3368static int __init proc_modules_init(void)
3369{
3370 proc_create("modules", 0, NULL, &proc_modules_operations);
3371 return 0;
3372}
3373module_init(proc_modules_init);
3374#endif
3375
3376/* Given an address, look for it in the module exception tables. */
3377const struct exception_table_entry *search_module_extables(unsigned long addr)
3378{
3379 const struct exception_table_entry *e = NULL;
3380 struct module *mod;
3381
3382 preempt_disable();
3383 list_for_each_entry_rcu(mod, &modules, list) {
3384 if (mod->num_exentries == 0)
3385 continue;
3386
3387 e = search_extable(mod->extable,
3388 mod->extable + mod->num_exentries - 1,
3389 addr);
3390 if (e)
3391 break;
3392 }
3393 preempt_enable();
3394
3395 /* Now, if we found one, we are running inside it now, hence
3396 we cannot unload the module, hence no refcnt needed. */
3397 return e;
3398}
3399
3400/*
3401 * is_module_address - is this address inside a module?
3402 * @addr: the address to check.
3403 *
3404 * See is_module_text_address() if you simply want to see if the address
3405 * is code (not data).
3406 */
3407bool is_module_address(unsigned long addr)
3408{
3409 bool ret;
3410
3411 preempt_disable();
3412 ret = __module_address(addr) != NULL;
3413 preempt_enable();
3414
3415 return ret;
3416}
3417
3418/*
3419 * __module_address - get the module which contains an address.
3420 * @addr: the address.
3421 *
3422 * Must be called with preempt disabled or module mutex held so that
3423 * module doesn't get freed during this.
3424 */
3425struct module *__module_address(unsigned long addr)
3426{
3427 struct module *mod;
3428
3429 if (addr < module_addr_min || addr > module_addr_max)
3430 return NULL;
3431
3432 list_for_each_entry_rcu(mod, &modules, list)
3433 if (within_module_core(addr, mod)
3434 || within_module_init(addr, mod))
3435 return mod;
3436 return NULL;
3437}
3438EXPORT_SYMBOL_GPL(__module_address);
3439
3440/*
3441 * is_module_text_address - is this address inside module code?
3442 * @addr: the address to check.
3443 *
3444 * See is_module_address() if you simply want to see if the address is
3445 * anywhere in a module. See kernel_text_address() for testing if an
3446 * address corresponds to kernel or module code.
3447 */
3448bool is_module_text_address(unsigned long addr)
3449{
3450 bool ret;
3451
3452 preempt_disable();
3453 ret = __module_text_address(addr) != NULL;
3454 preempt_enable();
3455
3456 return ret;
3457}
3458
3459/*
3460 * __module_text_address - get the module whose code contains an address.
3461 * @addr: the address.
3462 *
3463 * Must be called with preempt disabled or module mutex held so that
3464 * module doesn't get freed during this.
3465 */
3466struct module *__module_text_address(unsigned long addr)
3467{
3468 struct module *mod = __module_address(addr);
3469 if (mod) {
3470 /* Make sure it's within the text section. */
3471 if (!within(addr, mod->module_init, mod->init_text_size)
3472 && !within(addr, mod->module_core, mod->core_text_size))
3473 mod = NULL;
3474 }
3475 return mod;
3476}
3477EXPORT_SYMBOL_GPL(__module_text_address);
3478
3479/* Don't grab lock, we're oopsing. */
3480void print_modules(void)
3481{
3482 struct module *mod;
3483 char buf[8];
3484
3485 printk(KERN_DEFAULT "Modules linked in:");
3486 /* Most callers should already have preempt disabled, but make sure */
3487 preempt_disable();
3488 list_for_each_entry_rcu(mod, &modules, list)
3489 printk(" %s%s", mod->name, module_flags(mod, buf));
3490 preempt_enable();
3491 if (last_unloaded_module[0])
3492 printk(" [last unloaded: %s]", last_unloaded_module);
3493 printk("\n");
3494}
3495
3496#ifdef CONFIG_MODVERSIONS
3497/* Generate the signature for all relevant module structures here.
3498 * If these change, we don't want to try to parse the module. */
3499void module_layout(struct module *mod,
3500 struct modversion_info *ver,
3501 struct kernel_param *kp,
3502 struct kernel_symbol *ks,
3503 struct tracepoint * const *tp)
3504{
3505}
3506EXPORT_SYMBOL(module_layout);
3507#endif