projects/linux·blob v2.6.38-rc2 · refs

3447 lines · 87.7 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/module.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
61#define CREATE_TRACE_POINTS
62#include <trace/events/module.h>
63
64#if 0
65#define DEBUGP printk
66#else
67#define DEBUGP(fmt , a...)
68#endif
69
70#ifndef ARCH_SHF_SMALL
71#define ARCH_SHF_SMALL 0
72#endif
73
74/*
75 * Modules' sections will be aligned on page boundaries
76 * to ensure complete separation of code and data, but
77 * only when CONFIG_DEBUG_SET_MODULE_RONX=y
78 */
79#ifdef CONFIG_DEBUG_SET_MODULE_RONX
80# define debug_align(X) ALIGN(X, PAGE_SIZE)
81#else
82# define debug_align(X) (X)
83#endif
84
85/*
86 * Given BASE and SIZE this macro calculates the number of pages the
87 * memory regions occupies
88 */
89#define MOD_NUMBER_OF_PAGES(BASE, SIZE) (((SIZE) > 0) ? \
90 (PFN_DOWN((unsigned long)(BASE) + (SIZE) - 1) - \
91 PFN_DOWN((unsigned long)BASE) + 1) \
92 : (0UL))
93
94/* If this is set, the section belongs in the init part of the module */
95#define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
96
97/*
98 * Mutex protects:
99 * 1) List of modules (also safely readable with preempt_disable),
100 * 2) module_use links,
101 * 3) module_addr_min/module_addr_max.
102 * (delete uses stop_machine/add uses RCU list operations). */
103DEFINE_MUTEX(module_mutex);
104EXPORT_SYMBOL_GPL(module_mutex);
105static LIST_HEAD(modules);
106#ifdef CONFIG_KGDB_KDB
107struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
108#endif /* CONFIG_KGDB_KDB */
109
110
111/* Block module loading/unloading? */
112int modules_disabled = 0;
113
114/* Waiting for a module to finish initializing? */
115static DECLARE_WAIT_QUEUE_HEAD(module_wq);
116
117static BLOCKING_NOTIFIER_HEAD(module_notify_list);
118
119/* Bounds of module allocation, for speeding __module_address.
120 * Protected by module_mutex. */
121static unsigned long module_addr_min = -1UL, module_addr_max = 0;
122
123int register_module_notifier(struct notifier_block * nb)
124{
125 return blocking_notifier_chain_register(&module_notify_list, nb);
126}
127EXPORT_SYMBOL(register_module_notifier);
128
129int unregister_module_notifier(struct notifier_block * nb)
130{
131 return blocking_notifier_chain_unregister(&module_notify_list, nb);
132}
133EXPORT_SYMBOL(unregister_module_notifier);
134
135struct load_info {
136 Elf_Ehdr *hdr;
137 unsigned long len;
138 Elf_Shdr *sechdrs;
139 char *secstrings, *strtab;
140 unsigned long *strmap;
141 unsigned long symoffs, stroffs;
142 struct _ddebug *debug;
143 unsigned int num_debug;
144 struct {
145 unsigned int sym, str, mod, vers, info, pcpu;
146 } index;
147};
148
149/* We require a truly strong try_module_get(): 0 means failure due to
150 ongoing or failed initialization etc. */
151static inline int strong_try_module_get(struct module *mod)
152{
153 if (mod && mod->state == MODULE_STATE_COMING)
154 return -EBUSY;
155 if (try_module_get(mod))
156 return 0;
157 else
158 return -ENOENT;
159}
160
161static inline void add_taint_module(struct module *mod, unsigned flag)
162{
163 add_taint(flag);
164 mod->taints |= (1U << flag);
165}
166
167/*
168 * A thread that wants to hold a reference to a module only while it
169 * is running can call this to safely exit. nfsd and lockd use this.
170 */
171void __module_put_and_exit(struct module *mod, long code)
172{
173 module_put(mod);
174 do_exit(code);
175}
176EXPORT_SYMBOL(__module_put_and_exit);
177
178/* Find a module section: 0 means not found. */
179static unsigned int find_sec(const struct load_info *info, const char *name)
180{
181 unsigned int i;
182
183 for (i = 1; i < info->hdr->e_shnum; i++) {
184 Elf_Shdr *shdr = &info->sechdrs[i];
185 /* Alloc bit cleared means "ignore it." */
186 if ((shdr->sh_flags & SHF_ALLOC)
187 && strcmp(info->secstrings + shdr->sh_name, name) == 0)
188 return i;
189 }
190 return 0;
191}
192
193/* Find a module section, or NULL. */
194static void *section_addr(const struct load_info *info, const char *name)
195{
196 /* Section 0 has sh_addr 0. */
197 return (void *)info->sechdrs[find_sec(info, name)].sh_addr;
198}
199
200/* Find a module section, or NULL. Fill in number of "objects" in section. */
201static void *section_objs(const struct load_info *info,
202 const char *name,
203 size_t object_size,
204 unsigned int *num)
205{
206 unsigned int sec = find_sec(info, name);
207
208 /* Section 0 has sh_addr 0 and sh_size 0. */
209 *num = info->sechdrs[sec].sh_size / object_size;
210 return (void *)info->sechdrs[sec].sh_addr;
211}
212
213/* Provided by the linker */
214extern const struct kernel_symbol __start___ksymtab[];
215extern const struct kernel_symbol __stop___ksymtab[];
216extern const struct kernel_symbol __start___ksymtab_gpl[];
217extern const struct kernel_symbol __stop___ksymtab_gpl[];
218extern const struct kernel_symbol __start___ksymtab_gpl_future[];
219extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
220extern const unsigned long __start___kcrctab[];
221extern const unsigned long __start___kcrctab_gpl[];
222extern const unsigned long __start___kcrctab_gpl_future[];
223#ifdef CONFIG_UNUSED_SYMBOLS
224extern const struct kernel_symbol __start___ksymtab_unused[];
225extern const struct kernel_symbol __stop___ksymtab_unused[];
226extern const struct kernel_symbol __start___ksymtab_unused_gpl[];
227extern const struct kernel_symbol __stop___ksymtab_unused_gpl[];
228extern const unsigned long __start___kcrctab_unused[];
229extern const unsigned long __start___kcrctab_unused_gpl[];
230#endif
231
232#ifndef CONFIG_MODVERSIONS
233#define symversion(base, idx) NULL
234#else
235#define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
236#endif
237
238static bool each_symbol_in_section(const struct symsearch *arr,
239 unsigned int arrsize,
240 struct module *owner,
241 bool (*fn)(const struct symsearch *syms,
242 struct module *owner,
243 unsigned int symnum, void *data),
244 void *data)
245{
246 unsigned int i, j;
247
248 for (j = 0; j < arrsize; j++) {
249 for (i = 0; i < arr[j].stop - arr[j].start; i++)
250 if (fn(&arr[j], owner, i, data))
251 return true;
252 }
253
254 return false;
255}
256
257/* Returns true as soon as fn returns true, otherwise false. */
258bool each_symbol(bool (*fn)(const struct symsearch *arr, struct module *owner,
259 unsigned int symnum, void *data), void *data)
260{
261 struct module *mod;
262 static const struct symsearch arr[] = {
263 { __start___ksymtab, __stop___ksymtab, __start___kcrctab,
264 NOT_GPL_ONLY, false },
265 { __start___ksymtab_gpl, __stop___ksymtab_gpl,
266 __start___kcrctab_gpl,
267 GPL_ONLY, false },
268 { __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future,
269 __start___kcrctab_gpl_future,
270 WILL_BE_GPL_ONLY, false },
271#ifdef CONFIG_UNUSED_SYMBOLS
272 { __start___ksymtab_unused, __stop___ksymtab_unused,
273 __start___kcrctab_unused,
274 NOT_GPL_ONLY, true },
275 { __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl,
276 __start___kcrctab_unused_gpl,
277 GPL_ONLY, true },
278#endif
279 };
280
281 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data))
282 return true;
283
284 list_for_each_entry_rcu(mod, &modules, list) {
285 struct symsearch arr[] = {
286 { mod->syms, mod->syms + mod->num_syms, mod->crcs,
287 NOT_GPL_ONLY, false },
288 { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
289 mod->gpl_crcs,
290 GPL_ONLY, false },
291 { mod->gpl_future_syms,
292 mod->gpl_future_syms + mod->num_gpl_future_syms,
293 mod->gpl_future_crcs,
294 WILL_BE_GPL_ONLY, false },
295#ifdef CONFIG_UNUSED_SYMBOLS
296 { mod->unused_syms,
297 mod->unused_syms + mod->num_unused_syms,
298 mod->unused_crcs,
299 NOT_GPL_ONLY, true },
300 { mod->unused_gpl_syms,
301 mod->unused_gpl_syms + mod->num_unused_gpl_syms,
302 mod->unused_gpl_crcs,
303 GPL_ONLY, true },
304#endif
305 };
306
307 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data))
308 return true;
309 }
310 return false;
311}
312EXPORT_SYMBOL_GPL(each_symbol);
313
314struct find_symbol_arg {
315 /* Input */
316 const char *name;
317 bool gplok;
318 bool warn;
319
320 /* Output */
321 struct module *owner;
322 const unsigned long *crc;
323 const struct kernel_symbol *sym;
324};
325
326static bool find_symbol_in_section(const struct symsearch *syms,
327 struct module *owner,
328 unsigned int symnum, void *data)
329{
330 struct find_symbol_arg *fsa = data;
331
332 if (strcmp(syms->start[symnum].name, fsa->name) != 0)
333 return false;
334
335 if (!fsa->gplok) {
336 if (syms->licence == GPL_ONLY)
337 return false;
338 if (syms->licence == WILL_BE_GPL_ONLY && fsa->warn) {
339 printk(KERN_WARNING "Symbol %s is being used "
340 "by a non-GPL module, which will not "
341 "be allowed in the future\n", fsa->name);
342 printk(KERN_WARNING "Please see the file "
343 "Documentation/feature-removal-schedule.txt "
344 "in the kernel source tree for more details.\n");
345 }
346 }
347
348#ifdef CONFIG_UNUSED_SYMBOLS
349 if (syms->unused && fsa->warn) {
350 printk(KERN_WARNING "Symbol %s is marked as UNUSED, "
351 "however this module is using it.\n", fsa->name);
352 printk(KERN_WARNING
353 "This symbol will go away in the future.\n");
354 printk(KERN_WARNING
355 "Please evalute if this is the right api to use and if "
356 "it really is, submit a report the linux kernel "
357 "mailinglist together with submitting your code for "
358 "inclusion.\n");
359 }
360#endif
361
362 fsa->owner = owner;
363 fsa->crc = symversion(syms->crcs, symnum);
364 fsa->sym = &syms->start[symnum];
365 return true;
366}
367
368/* Find a symbol and return it, along with, (optional) crc and
369 * (optional) module which owns it. Needs preempt disabled or module_mutex. */
370const struct kernel_symbol *find_symbol(const char *name,
371 struct module **owner,
372 const unsigned long **crc,
373 bool gplok,
374 bool warn)
375{
376 struct find_symbol_arg fsa;
377
378 fsa.name = name;
379 fsa.gplok = gplok;
380 fsa.warn = warn;
381
382 if (each_symbol(find_symbol_in_section, &fsa)) {
383 if (owner)
384 *owner = fsa.owner;
385 if (crc)
386 *crc = fsa.crc;
387 return fsa.sym;
388 }
389
390 DEBUGP("Failed to find symbol %s\n", name);
391 return NULL;
392}
393EXPORT_SYMBOL_GPL(find_symbol);
394
395/* Search for module by name: must hold module_mutex. */
396struct module *find_module(const char *name)
397{
398 struct module *mod;
399
400 list_for_each_entry(mod, &modules, list) {
401 if (strcmp(mod->name, name) == 0)
402 return mod;
403 }
404 return NULL;
405}
406EXPORT_SYMBOL_GPL(find_module);
407
408#ifdef CONFIG_SMP
409
410static inline void __percpu *mod_percpu(struct module *mod)
411{
412 return mod->percpu;
413}
414
415static int percpu_modalloc(struct module *mod,
416 unsigned long size, unsigned long align)
417{
418 if (align > PAGE_SIZE) {
419 printk(KERN_WARNING "%s: per-cpu alignment %li > %li\n",
420 mod->name, align, PAGE_SIZE);
421 align = PAGE_SIZE;
422 }
423
424 mod->percpu = __alloc_reserved_percpu(size, align);
425 if (!mod->percpu) {
426 printk(KERN_WARNING
427 "%s: Could not allocate %lu bytes percpu data\n",
428 mod->name, size);
429 return -ENOMEM;
430 }
431 mod->percpu_size = size;
432 return 0;
433}
434
435static void percpu_modfree(struct module *mod)
436{
437 free_percpu(mod->percpu);
438}
439
440static unsigned int find_pcpusec(struct load_info *info)
441{
442 return find_sec(info, ".data..percpu");
443}
444
445static void percpu_modcopy(struct module *mod,
446 const void *from, unsigned long size)
447{
448 int cpu;
449
450 for_each_possible_cpu(cpu)
451 memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
452}
453
454/**
455 * is_module_percpu_address - test whether address is from module static percpu
456 * @addr: address to test
457 *
458 * Test whether @addr belongs to module static percpu area.
459 *
460 * RETURNS:
461 * %true if @addr is from module static percpu area
462 */
463bool is_module_percpu_address(unsigned long addr)
464{
465 struct module *mod;
466 unsigned int cpu;
467
468 preempt_disable();
469
470 list_for_each_entry_rcu(mod, &modules, list) {
471 if (!mod->percpu_size)
472 continue;
473 for_each_possible_cpu(cpu) {
474 void *start = per_cpu_ptr(mod->percpu, cpu);
475
476 if ((void *)addr >= start &&
477 (void *)addr < start + mod->percpu_size) {
478 preempt_enable();
479 return true;
480 }
481 }
482 }
483
484 preempt_enable();
485 return false;
486}
487
488#else /* ... !CONFIG_SMP */
489
490static inline void __percpu *mod_percpu(struct module *mod)
491{
492 return NULL;
493}
494static inline int percpu_modalloc(struct module *mod,
495 unsigned long size, unsigned long align)
496{
497 return -ENOMEM;
498}
499static inline void percpu_modfree(struct module *mod)
500{
501}
502static unsigned int find_pcpusec(struct load_info *info)
503{
504 return 0;
505}
506static inline void percpu_modcopy(struct module *mod,
507 const void *from, unsigned long size)
508{
509 /* pcpusec should be 0, and size of that section should be 0. */
510 BUG_ON(size != 0);
511}
512bool is_module_percpu_address(unsigned long addr)
513{
514 return false;
515}
516
517#endif /* CONFIG_SMP */
518
519#define MODINFO_ATTR(field) \
520static void setup_modinfo_##field(struct module *mod, const char *s) \
521{ \
522 mod->field = kstrdup(s, GFP_KERNEL); \
523} \
524static ssize_t show_modinfo_##field(struct module_attribute *mattr, \
525 struct module *mod, char *buffer) \
526{ \
527 return sprintf(buffer, "%s\n", mod->field); \
528} \
529static int modinfo_##field##_exists(struct module *mod) \
530{ \
531 return mod->field != NULL; \
532} \
533static void free_modinfo_##field(struct module *mod) \
534{ \
535 kfree(mod->field); \
536 mod->field = NULL; \
537} \
538static struct module_attribute modinfo_##field = { \
539 .attr = { .name = __stringify(field), .mode = 0444 }, \
540 .show = show_modinfo_##field, \
541 .setup = setup_modinfo_##field, \
542 .test = modinfo_##field##_exists, \
543 .free = free_modinfo_##field, \
544};
545
546MODINFO_ATTR(version);
547MODINFO_ATTR(srcversion);
548
549static char last_unloaded_module[MODULE_NAME_LEN+1];
550
551#ifdef CONFIG_MODULE_UNLOAD
552
553EXPORT_TRACEPOINT_SYMBOL(module_get);
554
555/* Init the unload section of the module. */
556static int module_unload_init(struct module *mod)
557{
558 mod->refptr = alloc_percpu(struct module_ref);
559 if (!mod->refptr)
560 return -ENOMEM;
561
562 INIT_LIST_HEAD(&mod->source_list);
563 INIT_LIST_HEAD(&mod->target_list);
564
565 /* Hold reference count during initialization. */
566 __this_cpu_write(mod->refptr->incs, 1);
567 /* Backwards compatibility macros put refcount during init. */
568 mod->waiter = current;
569
570 return 0;
571}
572
573/* Does a already use b? */
574static int already_uses(struct module *a, struct module *b)
575{
576 struct module_use *use;
577
578 list_for_each_entry(use, &b->source_list, source_list) {
579 if (use->source == a) {
580 DEBUGP("%s uses %s!\n", a->name, b->name);
581 return 1;
582 }
583 }
584 DEBUGP("%s does not use %s!\n", a->name, b->name);
585 return 0;
586}
587
588/*
589 * Module a uses b
590 * - we add 'a' as a "source", 'b' as a "target" of module use
591 * - the module_use is added to the list of 'b' sources (so
592 * 'b' can walk the list to see who sourced them), and of 'a'
593 * targets (so 'a' can see what modules it targets).
594 */
595static int add_module_usage(struct module *a, struct module *b)
596{
597 struct module_use *use;
598
599 DEBUGP("Allocating new usage for %s.\n", a->name);
600 use = kmalloc(sizeof(*use), GFP_ATOMIC);
601 if (!use) {
602 printk(KERN_WARNING "%s: out of memory loading\n", a->name);
603 return -ENOMEM;
604 }
605
606 use->source = a;
607 use->target = b;
608 list_add(&use->source_list, &b->source_list);
609 list_add(&use->target_list, &a->target_list);
610 return 0;
611}
612
613/* Module a uses b: caller needs module_mutex() */
614int ref_module(struct module *a, struct module *b)
615{
616 int err;
617
618 if (b == NULL || already_uses(a, b))
619 return 0;
620
621 /* If module isn't available, we fail. */
622 err = strong_try_module_get(b);
623 if (err)
624 return err;
625
626 err = add_module_usage(a, b);
627 if (err) {
628 module_put(b);
629 return err;
630 }
631 return 0;
632}
633EXPORT_SYMBOL_GPL(ref_module);
634
635/* Clear the unload stuff of the module. */
636static void module_unload_free(struct module *mod)
637{
638 struct module_use *use, *tmp;
639
640 mutex_lock(&module_mutex);
641 list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
642 struct module *i = use->target;
643 DEBUGP("%s unusing %s\n", mod->name, i->name);
644 module_put(i);
645 list_del(&use->source_list);
646 list_del(&use->target_list);
647 kfree(use);
648 }
649 mutex_unlock(&module_mutex);
650
651 free_percpu(mod->refptr);
652}
653
654#ifdef CONFIG_MODULE_FORCE_UNLOAD
655static inline int try_force_unload(unsigned int flags)
656{
657 int ret = (flags & O_TRUNC);
658 if (ret)
659 add_taint(TAINT_FORCED_RMMOD);
660 return ret;
661}
662#else
663static inline int try_force_unload(unsigned int flags)
664{
665 return 0;
666}
667#endif /* CONFIG_MODULE_FORCE_UNLOAD */
668
669struct stopref
670{
671 struct module *mod;
672 int flags;
673 int *forced;
674};
675
676/* Whole machine is stopped with interrupts off when this runs. */
677static int __try_stop_module(void *_sref)
678{
679 struct stopref *sref = _sref;
680
681 /* If it's not unused, quit unless we're forcing. */
682 if (module_refcount(sref->mod) != 0) {
683 if (!(*sref->forced = try_force_unload(sref->flags)))
684 return -EWOULDBLOCK;
685 }
686
687 /* Mark it as dying. */
688 sref->mod->state = MODULE_STATE_GOING;
689 return 0;
690}
691
692static int try_stop_module(struct module *mod, int flags, int *forced)
693{
694 if (flags & O_NONBLOCK) {
695 struct stopref sref = { mod, flags, forced };
696
697 return stop_machine(__try_stop_module, &sref, NULL);
698 } else {
699 /* We don't need to stop the machine for this. */
700 mod->state = MODULE_STATE_GOING;
701 synchronize_sched();
702 return 0;
703 }
704}
705
706unsigned int module_refcount(struct module *mod)
707{
708 unsigned int incs = 0, decs = 0;
709 int cpu;
710
711 for_each_possible_cpu(cpu)
712 decs += per_cpu_ptr(mod->refptr, cpu)->decs;
713 /*
714 * ensure the incs are added up after the decs.
715 * module_put ensures incs are visible before decs with smp_wmb.
716 *
717 * This 2-count scheme avoids the situation where the refcount
718 * for CPU0 is read, then CPU0 increments the module refcount,
719 * then CPU1 drops that refcount, then the refcount for CPU1 is
720 * read. We would record a decrement but not its corresponding
721 * increment so we would see a low count (disaster).
722 *
723 * Rare situation? But module_refcount can be preempted, and we
724 * might be tallying up 4096+ CPUs. So it is not impossible.
725 */
726 smp_rmb();
727 for_each_possible_cpu(cpu)
728 incs += per_cpu_ptr(mod->refptr, cpu)->incs;
729 return incs - decs;
730}
731EXPORT_SYMBOL(module_refcount);
732
733/* This exists whether we can unload or not */
734static void free_module(struct module *mod);
735
736static void wait_for_zero_refcount(struct module *mod)
737{
738 /* Since we might sleep for some time, release the mutex first */
739 mutex_unlock(&module_mutex);
740 for (;;) {
741 DEBUGP("Looking at refcount...\n");
742 set_current_state(TASK_UNINTERRUPTIBLE);
743 if (module_refcount(mod) == 0)
744 break;
745 schedule();
746 }
747 current->state = TASK_RUNNING;
748 mutex_lock(&module_mutex);
749}
750
751SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
752 unsigned int, flags)
753{
754 struct module *mod;
755 char name[MODULE_NAME_LEN];
756 int ret, forced = 0;
757
758 if (!capable(CAP_SYS_MODULE) || modules_disabled)
759 return -EPERM;
760
761 if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
762 return -EFAULT;
763 name[MODULE_NAME_LEN-1] = '\0';
764
765 if (mutex_lock_interruptible(&module_mutex) != 0)
766 return -EINTR;
767
768 mod = find_module(name);
769 if (!mod) {
770 ret = -ENOENT;
771 goto out;
772 }
773
774 if (!list_empty(&mod->source_list)) {
775 /* Other modules depend on us: get rid of them first. */
776 ret = -EWOULDBLOCK;
777 goto out;
778 }
779
780 /* Doing init or already dying? */
781 if (mod->state != MODULE_STATE_LIVE) {
782 /* FIXME: if (force), slam module count and wake up
783 waiter --RR */
784 DEBUGP("%s already dying\n", mod->name);
785 ret = -EBUSY;
786 goto out;
787 }
788
789 /* If it has an init func, it must have an exit func to unload */
790 if (mod->init && !mod->exit) {
791 forced = try_force_unload(flags);
792 if (!forced) {
793 /* This module can't be removed */
794 ret = -EBUSY;
795 goto out;
796 }
797 }
798
799 /* Set this up before setting mod->state */
800 mod->waiter = current;
801
802 /* Stop the machine so refcounts can't move and disable module. */
803 ret = try_stop_module(mod, flags, &forced);
804 if (ret != 0)
805 goto out;
806
807 /* Never wait if forced. */
808 if (!forced && module_refcount(mod) != 0)
809 wait_for_zero_refcount(mod);
810
811 mutex_unlock(&module_mutex);
812 /* Final destruction now noone is using it. */
813 if (mod->exit != NULL)
814 mod->exit();
815 blocking_notifier_call_chain(&module_notify_list,
816 MODULE_STATE_GOING, mod);
817 async_synchronize_full();
818
819 /* Store the name of the last unloaded module for diagnostic purposes */
820 strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
821
822 free_module(mod);
823 return 0;
824out:
825 mutex_unlock(&module_mutex);
826 return ret;
827}
828
829static inline void print_unload_info(struct seq_file *m, struct module *mod)
830{
831 struct module_use *use;
832 int printed_something = 0;
833
834 seq_printf(m, " %u ", module_refcount(mod));
835
836 /* Always include a trailing , so userspace can differentiate
837 between this and the old multi-field proc format. */
838 list_for_each_entry(use, &mod->source_list, source_list) {
839 printed_something = 1;
840 seq_printf(m, "%s,", use->source->name);
841 }
842
843 if (mod->init != NULL && mod->exit == NULL) {
844 printed_something = 1;
845 seq_printf(m, "[permanent],");
846 }
847
848 if (!printed_something)
849 seq_printf(m, "-");
850}
851
852void __symbol_put(const char *symbol)
853{
854 struct module *owner;
855
856 preempt_disable();
857 if (!find_symbol(symbol, &owner, NULL, true, false))
858 BUG();
859 module_put(owner);
860 preempt_enable();
861}
862EXPORT_SYMBOL(__symbol_put);
863
864/* Note this assumes addr is a function, which it currently always is. */
865void symbol_put_addr(void *addr)
866{
867 struct module *modaddr;
868 unsigned long a = (unsigned long)dereference_function_descriptor(addr);
869
870 if (core_kernel_text(a))
871 return;
872
873 /* module_text_address is safe here: we're supposed to have reference
874 * to module from symbol_get, so it can't go away. */
875 modaddr = __module_text_address(a);
876 BUG_ON(!modaddr);
877 module_put(modaddr);
878}
879EXPORT_SYMBOL_GPL(symbol_put_addr);
880
881static ssize_t show_refcnt(struct module_attribute *mattr,
882 struct module *mod, char *buffer)
883{
884 return sprintf(buffer, "%u\n", module_refcount(mod));
885}
886
887static struct module_attribute refcnt = {
888 .attr = { .name = "refcnt", .mode = 0444 },
889 .show = show_refcnt,
890};
891
892void module_put(struct module *module)
893{
894 if (module) {
895 preempt_disable();
896 smp_wmb(); /* see comment in module_refcount */
897 __this_cpu_inc(module->refptr->decs);
898
899 trace_module_put(module, _RET_IP_);
900 /* Maybe they're waiting for us to drop reference? */
901 if (unlikely(!module_is_live(module)))
902 wake_up_process(module->waiter);
903 preempt_enable();
904 }
905}
906EXPORT_SYMBOL(module_put);
907
908#else /* !CONFIG_MODULE_UNLOAD */
909static inline void print_unload_info(struct seq_file *m, struct module *mod)
910{
911 /* We don't know the usage count, or what modules are using. */
912 seq_printf(m, " - -");
913}
914
915static inline void module_unload_free(struct module *mod)
916{
917}
918
919int ref_module(struct module *a, struct module *b)
920{
921 return strong_try_module_get(b);
922}
923EXPORT_SYMBOL_GPL(ref_module);
924
925static inline int module_unload_init(struct module *mod)
926{
927 return 0;
928}
929#endif /* CONFIG_MODULE_UNLOAD */
930
931static ssize_t show_initstate(struct module_attribute *mattr,
932 struct module *mod, char *buffer)
933{
934 const char *state = "unknown";
935
936 switch (mod->state) {
937 case MODULE_STATE_LIVE:
938 state = "live";
939 break;
940 case MODULE_STATE_COMING:
941 state = "coming";
942 break;
943 case MODULE_STATE_GOING:
944 state = "going";
945 break;
946 }
947 return sprintf(buffer, "%s\n", state);
948}
949
950static struct module_attribute initstate = {
951 .attr = { .name = "initstate", .mode = 0444 },
952 .show = show_initstate,
953};
954
955static struct module_attribute *modinfo_attrs[] = {
956 &modinfo_version,
957 &modinfo_srcversion,
958 &initstate,
959#ifdef CONFIG_MODULE_UNLOAD
960 &refcnt,
961#endif
962 NULL,
963};
964
965static const char vermagic[] = VERMAGIC_STRING;
966
967static int try_to_force_load(struct module *mod, const char *reason)
968{
969#ifdef CONFIG_MODULE_FORCE_LOAD
970 if (!test_taint(TAINT_FORCED_MODULE))
971 printk(KERN_WARNING "%s: %s: kernel tainted.\n",
972 mod->name, reason);
973 add_taint_module(mod, TAINT_FORCED_MODULE);
974 return 0;
975#else
976 return -ENOEXEC;
977#endif
978}
979
980#ifdef CONFIG_MODVERSIONS
981/* If the arch applies (non-zero) relocations to kernel kcrctab, unapply it. */
982static unsigned long maybe_relocated(unsigned long crc,
983 const struct module *crc_owner)
984{
985#ifdef ARCH_RELOCATES_KCRCTAB
986 if (crc_owner == NULL)
987 return crc - (unsigned long)reloc_start;
988#endif
989 return crc;
990}
991
992static int check_version(Elf_Shdr *sechdrs,
993 unsigned int versindex,
994 const char *symname,
995 struct module *mod,
996 const unsigned long *crc,
997 const struct module *crc_owner)
998{
999 unsigned int i, num_versions;
1000 struct modversion_info *versions;
1001
1002 /* Exporting module didn't supply crcs? OK, we're already tainted. */
1003 if (!crc)
1004 return 1;
1005
1006 /* No versions at all? modprobe --force does this. */
1007 if (versindex == 0)
1008 return try_to_force_load(mod, symname) == 0;
1009
1010 versions = (void *) sechdrs[versindex].sh_addr;
1011 num_versions = sechdrs[versindex].sh_size
1012 / sizeof(struct modversion_info);
1013
1014 for (i = 0; i < num_versions; i++) {
1015 if (strcmp(versions[i].name, symname) != 0)
1016 continue;
1017
1018 if (versions[i].crc == maybe_relocated(*crc, crc_owner))
1019 return 1;
1020 DEBUGP("Found checksum %lX vs module %lX\n",
1021 maybe_relocated(*crc, crc_owner), versions[i].crc);
1022 goto bad_version;
1023 }
1024
1025 printk(KERN_WARNING "%s: no symbol version for %s\n",
1026 mod->name, symname);
1027 return 0;
1028
1029bad_version:
1030 printk("%s: disagrees about version of symbol %s\n",
1031 mod->name, symname);
1032 return 0;
1033}
1034
1035static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1036 unsigned int versindex,
1037 struct module *mod)
1038{
1039 const unsigned long *crc;
1040
1041 /* Since this should be found in kernel (which can't be removed),
1042 * no locking is necessary. */
1043 if (!find_symbol(MODULE_SYMBOL_PREFIX "module_layout", NULL,
1044 &crc, true, false))
1045 BUG();
1046 return check_version(sechdrs, versindex, "module_layout", mod, crc,
1047 NULL);
1048}
1049
1050/* First part is kernel version, which we ignore if module has crcs. */
1051static inline int same_magic(const char *amagic, const char *bmagic,
1052 bool has_crcs)
1053{
1054 if (has_crcs) {
1055 amagic += strcspn(amagic, " ");
1056 bmagic += strcspn(bmagic, " ");
1057 }
1058 return strcmp(amagic, bmagic) == 0;
1059}
1060#else
1061static inline int check_version(Elf_Shdr *sechdrs,
1062 unsigned int versindex,
1063 const char *symname,
1064 struct module *mod,
1065 const unsigned long *crc,
1066 const struct module *crc_owner)
1067{
1068 return 1;
1069}
1070
1071static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1072 unsigned int versindex,
1073 struct module *mod)
1074{
1075 return 1;
1076}
1077
1078static inline int same_magic(const char *amagic, const char *bmagic,
1079 bool has_crcs)
1080{
1081 return strcmp(amagic, bmagic) == 0;
1082}
1083#endif /* CONFIG_MODVERSIONS */
1084
1085/* Resolve a symbol for this module. I.e. if we find one, record usage. */
1086static const struct kernel_symbol *resolve_symbol(struct module *mod,
1087 const struct load_info *info,
1088 const char *name,
1089 char ownername[])
1090{
1091 struct module *owner;
1092 const struct kernel_symbol *sym;
1093 const unsigned long *crc;
1094 int err;
1095
1096 mutex_lock(&module_mutex);
1097 sym = find_symbol(name, &owner, &crc,
1098 !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
1099 if (!sym)
1100 goto unlock;
1101
1102 if (!check_version(info->sechdrs, info->index.vers, name, mod, crc,
1103 owner)) {
1104 sym = ERR_PTR(-EINVAL);
1105 goto getname;
1106 }
1107
1108 err = ref_module(mod, owner);
1109 if (err) {
1110 sym = ERR_PTR(err);
1111 goto getname;
1112 }
1113
1114getname:
1115 /* We must make copy under the lock if we failed to get ref. */
1116 strncpy(ownername, module_name(owner), MODULE_NAME_LEN);
1117unlock:
1118 mutex_unlock(&module_mutex);
1119 return sym;
1120}
1121
1122static const struct kernel_symbol *
1123resolve_symbol_wait(struct module *mod,
1124 const struct load_info *info,
1125 const char *name)
1126{
1127 const struct kernel_symbol *ksym;
1128 char owner[MODULE_NAME_LEN];
1129
1130 if (wait_event_interruptible_timeout(module_wq,
1131 !IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
1132 || PTR_ERR(ksym) != -EBUSY,
1133 30 * HZ) <= 0) {
1134 printk(KERN_WARNING "%s: gave up waiting for init of module %s.\n",
1135 mod->name, owner);
1136 }
1137 return ksym;
1138}
1139
1140/*
1141 * /sys/module/foo/sections stuff
1142 * J. Corbet <[email protected]>
1143 */
1144#ifdef CONFIG_SYSFS
1145
1146#ifdef CONFIG_KALLSYMS
1147static inline bool sect_empty(const Elf_Shdr *sect)
1148{
1149 return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
1150}
1151
1152struct module_sect_attr
1153{
1154 struct module_attribute mattr;
1155 char *name;
1156 unsigned long address;
1157};
1158
1159struct module_sect_attrs
1160{
1161 struct attribute_group grp;
1162 unsigned int nsections;
1163 struct module_sect_attr attrs[0];
1164};
1165
1166static ssize_t module_sect_show(struct module_attribute *mattr,
1167 struct module *mod, char *buf)
1168{
1169 struct module_sect_attr *sattr =
1170 container_of(mattr, struct module_sect_attr, mattr);
1171 return sprintf(buf, "0x%lx\n", sattr->address);
1172}
1173
1174static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
1175{
1176 unsigned int section;
1177
1178 for (section = 0; section < sect_attrs->nsections; section++)
1179 kfree(sect_attrs->attrs[section].name);
1180 kfree(sect_attrs);
1181}
1182
1183static void add_sect_attrs(struct module *mod, const struct load_info *info)
1184{
1185 unsigned int nloaded = 0, i, size[2];
1186 struct module_sect_attrs *sect_attrs;
1187 struct module_sect_attr *sattr;
1188 struct attribute **gattr;
1189
1190 /* Count loaded sections and allocate structures */
1191 for (i = 0; i < info->hdr->e_shnum; i++)
1192 if (!sect_empty(&info->sechdrs[i]))
1193 nloaded++;
1194 size[0] = ALIGN(sizeof(*sect_attrs)
1195 + nloaded * sizeof(sect_attrs->attrs[0]),
1196 sizeof(sect_attrs->grp.attrs[0]));
1197 size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]);
1198 sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
1199 if (sect_attrs == NULL)
1200 return;
1201
1202 /* Setup section attributes. */
1203 sect_attrs->grp.name = "sections";
1204 sect_attrs->grp.attrs = (void *)sect_attrs + size[0];
1205
1206 sect_attrs->nsections = 0;
1207 sattr = &sect_attrs->attrs[0];
1208 gattr = &sect_attrs->grp.attrs[0];
1209 for (i = 0; i < info->hdr->e_shnum; i++) {
1210 Elf_Shdr *sec = &info->sechdrs[i];
1211 if (sect_empty(sec))
1212 continue;
1213 sattr->address = sec->sh_addr;
1214 sattr->name = kstrdup(info->secstrings + sec->sh_name,
1215 GFP_KERNEL);
1216 if (sattr->name == NULL)
1217 goto out;
1218 sect_attrs->nsections++;
1219 sysfs_attr_init(&sattr->mattr.attr);
1220 sattr->mattr.show = module_sect_show;
1221 sattr->mattr.store = NULL;
1222 sattr->mattr.attr.name = sattr->name;
1223 sattr->mattr.attr.mode = S_IRUGO;
1224 *(gattr++) = &(sattr++)->mattr.attr;
1225 }
1226 *gattr = NULL;
1227
1228 if (sysfs_create_group(&mod->mkobj.kobj, &sect_attrs->grp))
1229 goto out;
1230
1231 mod->sect_attrs = sect_attrs;
1232 return;
1233 out:
1234 free_sect_attrs(sect_attrs);
1235}
1236
1237static void remove_sect_attrs(struct module *mod)
1238{
1239 if (mod->sect_attrs) {
1240 sysfs_remove_group(&mod->mkobj.kobj,
1241 &mod->sect_attrs->grp);
1242 /* We are positive that no one is using any sect attrs
1243 * at this point. Deallocate immediately. */
1244 free_sect_attrs(mod->sect_attrs);
1245 mod->sect_attrs = NULL;
1246 }
1247}
1248
1249/*
1250 * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
1251 */
1252
1253struct module_notes_attrs {
1254 struct kobject *dir;
1255 unsigned int notes;
1256 struct bin_attribute attrs[0];
1257};
1258
1259static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
1260 struct bin_attribute *bin_attr,
1261 char *buf, loff_t pos, size_t count)
1262{
1263 /*
1264 * The caller checked the pos and count against our size.
1265 */
1266 memcpy(buf, bin_attr->private + pos, count);
1267 return count;
1268}
1269
1270static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
1271 unsigned int i)
1272{
1273 if (notes_attrs->dir) {
1274 while (i-- > 0)
1275 sysfs_remove_bin_file(notes_attrs->dir,
1276 &notes_attrs->attrs[i]);
1277 kobject_put(notes_attrs->dir);
1278 }
1279 kfree(notes_attrs);
1280}
1281
1282static void add_notes_attrs(struct module *mod, const struct load_info *info)
1283{
1284 unsigned int notes, loaded, i;
1285 struct module_notes_attrs *notes_attrs;
1286 struct bin_attribute *nattr;
1287
1288 /* failed to create section attributes, so can't create notes */
1289 if (!mod->sect_attrs)
1290 return;
1291
1292 /* Count notes sections and allocate structures. */
1293 notes = 0;
1294 for (i = 0; i < info->hdr->e_shnum; i++)
1295 if (!sect_empty(&info->sechdrs[i]) &&
1296 (info->sechdrs[i].sh_type == SHT_NOTE))
1297 ++notes;
1298
1299 if (notes == 0)
1300 return;
1301
1302 notes_attrs = kzalloc(sizeof(*notes_attrs)
1303 + notes * sizeof(notes_attrs->attrs[0]),
1304 GFP_KERNEL);
1305 if (notes_attrs == NULL)
1306 return;
1307
1308 notes_attrs->notes = notes;
1309 nattr = &notes_attrs->attrs[0];
1310 for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
1311 if (sect_empty(&info->sechdrs[i]))
1312 continue;
1313 if (info->sechdrs[i].sh_type == SHT_NOTE) {
1314 sysfs_bin_attr_init(nattr);
1315 nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
1316 nattr->attr.mode = S_IRUGO;
1317 nattr->size = info->sechdrs[i].sh_size;
1318 nattr->private = (void *) info->sechdrs[i].sh_addr;
1319 nattr->read = module_notes_read;
1320 ++nattr;
1321 }
1322 ++loaded;
1323 }
1324
1325 notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
1326 if (!notes_attrs->dir)
1327 goto out;
1328
1329 for (i = 0; i < notes; ++i)
1330 if (sysfs_create_bin_file(notes_attrs->dir,
1331 &notes_attrs->attrs[i]))
1332 goto out;
1333
1334 mod->notes_attrs = notes_attrs;
1335 return;
1336
1337 out:
1338 free_notes_attrs(notes_attrs, i);
1339}
1340
1341static void remove_notes_attrs(struct module *mod)
1342{
1343 if (mod->notes_attrs)
1344 free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
1345}
1346
1347#else
1348
1349static inline void add_sect_attrs(struct module *mod,
1350 const struct load_info *info)
1351{
1352}
1353
1354static inline void remove_sect_attrs(struct module *mod)
1355{
1356}
1357
1358static inline void add_notes_attrs(struct module *mod,
1359 const struct load_info *info)
1360{
1361}
1362
1363static inline void remove_notes_attrs(struct module *mod)
1364{
1365}
1366#endif /* CONFIG_KALLSYMS */
1367
1368static void add_usage_links(struct module *mod)
1369{
1370#ifdef CONFIG_MODULE_UNLOAD
1371 struct module_use *use;
1372 int nowarn;
1373
1374 mutex_lock(&module_mutex);
1375 list_for_each_entry(use, &mod->target_list, target_list) {
1376 nowarn = sysfs_create_link(use->target->holders_dir,
1377 &mod->mkobj.kobj, mod->name);
1378 }
1379 mutex_unlock(&module_mutex);
1380#endif
1381}
1382
1383static void del_usage_links(struct module *mod)
1384{
1385#ifdef CONFIG_MODULE_UNLOAD
1386 struct module_use *use;
1387
1388 mutex_lock(&module_mutex);
1389 list_for_each_entry(use, &mod->target_list, target_list)
1390 sysfs_remove_link(use->target->holders_dir, mod->name);
1391 mutex_unlock(&module_mutex);
1392#endif
1393}
1394
1395static int module_add_modinfo_attrs(struct module *mod)
1396{
1397 struct module_attribute *attr;
1398 struct module_attribute *temp_attr;
1399 int error = 0;
1400 int i;
1401
1402 mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
1403 (ARRAY_SIZE(modinfo_attrs) + 1)),
1404 GFP_KERNEL);
1405 if (!mod->modinfo_attrs)
1406 return -ENOMEM;
1407
1408 temp_attr = mod->modinfo_attrs;
1409 for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
1410 if (!attr->test ||
1411 (attr->test && attr->test(mod))) {
1412 memcpy(temp_attr, attr, sizeof(*temp_attr));
1413 sysfs_attr_init(&temp_attr->attr);
1414 error = sysfs_create_file(&mod->mkobj.kobj,&temp_attr->attr);
1415 ++temp_attr;
1416 }
1417 }
1418 return error;
1419}
1420
1421static void module_remove_modinfo_attrs(struct module *mod)
1422{
1423 struct module_attribute *attr;
1424 int i;
1425
1426 for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
1427 /* pick a field to test for end of list */
1428 if (!attr->attr.name)
1429 break;
1430 sysfs_remove_file(&mod->mkobj.kobj,&attr->attr);
1431 if (attr->free)
1432 attr->free(mod);
1433 }
1434 kfree(mod->modinfo_attrs);
1435}
1436
1437static int mod_sysfs_init(struct module *mod)
1438{
1439 int err;
1440 struct kobject *kobj;
1441
1442 if (!module_sysfs_initialized) {
1443 printk(KERN_ERR "%s: module sysfs not initialized\n",
1444 mod->name);
1445 err = -EINVAL;
1446 goto out;
1447 }
1448
1449 kobj = kset_find_obj(module_kset, mod->name);
1450 if (kobj) {
1451 printk(KERN_ERR "%s: module is already loaded\n", mod->name);
1452 kobject_put(kobj);
1453 err = -EINVAL;
1454 goto out;
1455 }
1456
1457 mod->mkobj.mod = mod;
1458
1459 memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
1460 mod->mkobj.kobj.kset = module_kset;
1461 err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
1462 "%s", mod->name);
1463 if (err)
1464 kobject_put(&mod->mkobj.kobj);
1465
1466 /* delay uevent until full sysfs population */
1467out:
1468 return err;
1469}
1470
1471static int mod_sysfs_setup(struct module *mod,
1472 const struct load_info *info,
1473 struct kernel_param *kparam,
1474 unsigned int num_params)
1475{
1476 int err;
1477
1478 err = mod_sysfs_init(mod);
1479 if (err)
1480 goto out;
1481
1482 mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1483 if (!mod->holders_dir) {
1484 err = -ENOMEM;
1485 goto out_unreg;
1486 }
1487
1488 err = module_param_sysfs_setup(mod, kparam, num_params);
1489 if (err)
1490 goto out_unreg_holders;
1491
1492 err = module_add_modinfo_attrs(mod);
1493 if (err)
1494 goto out_unreg_param;
1495
1496 add_usage_links(mod);
1497 add_sect_attrs(mod, info);
1498 add_notes_attrs(mod, info);
1499
1500 kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
1501 return 0;
1502
1503out_unreg_param:
1504 module_param_sysfs_remove(mod);
1505out_unreg_holders:
1506 kobject_put(mod->holders_dir);
1507out_unreg:
1508 kobject_put(&mod->mkobj.kobj);
1509out:
1510 return err;
1511}
1512
1513static void mod_sysfs_fini(struct module *mod)
1514{
1515 remove_notes_attrs(mod);
1516 remove_sect_attrs(mod);
1517 kobject_put(&mod->mkobj.kobj);
1518}
1519
1520#else /* !CONFIG_SYSFS */
1521
1522static int mod_sysfs_setup(struct module *mod,
1523 const struct load_info *info,
1524 struct kernel_param *kparam,
1525 unsigned int num_params)
1526{
1527 return 0;
1528}
1529
1530static void mod_sysfs_fini(struct module *mod)
1531{
1532}
1533
1534static void module_remove_modinfo_attrs(struct module *mod)
1535{
1536}
1537
1538static void del_usage_links(struct module *mod)
1539{
1540}
1541
1542#endif /* CONFIG_SYSFS */
1543
1544static void mod_sysfs_teardown(struct module *mod)
1545{
1546 del_usage_links(mod);
1547 module_remove_modinfo_attrs(mod);
1548 module_param_sysfs_remove(mod);
1549 kobject_put(mod->mkobj.drivers_dir);
1550 kobject_put(mod->holders_dir);
1551 mod_sysfs_fini(mod);
1552}
1553
1554/*
1555 * unlink the module with the whole machine is stopped with interrupts off
1556 * - this defends against kallsyms not taking locks
1557 */
1558static int __unlink_module(void *_mod)
1559{
1560 struct module *mod = _mod;
1561 list_del(&mod->list);
1562 module_bug_cleanup(mod);
1563 return 0;
1564}
1565
1566#ifdef CONFIG_DEBUG_SET_MODULE_RONX
1567/*
1568 * LKM RO/NX protection: protect module's text/ro-data
1569 * from modification and any data from execution.
1570 */
1571void set_page_attributes(void *start, void *end, int (*set)(unsigned long start, int num_pages))
1572{
1573 unsigned long begin_pfn = PFN_DOWN((unsigned long)start);
1574 unsigned long end_pfn = PFN_DOWN((unsigned long)end);
1575
1576 if (end_pfn > begin_pfn)
1577 set(begin_pfn << PAGE_SHIFT, end_pfn - begin_pfn);
1578}
1579
1580static void set_section_ro_nx(void *base,
1581 unsigned long text_size,
1582 unsigned long ro_size,
1583 unsigned long total_size)
1584{
1585 /* begin and end PFNs of the current subsection */
1586 unsigned long begin_pfn;
1587 unsigned long end_pfn;
1588
1589 /*
1590 * Set RO for module text and RO-data:
1591 * - Always protect first page.
1592 * - Do not protect last partial page.
1593 */
1594 if (ro_size > 0)
1595 set_page_attributes(base, base + ro_size, set_memory_ro);
1596
1597 /*
1598 * Set NX permissions for module data:
1599 * - Do not protect first partial page.
1600 * - Always protect last page.
1601 */
1602 if (total_size > text_size) {
1603 begin_pfn = PFN_UP((unsigned long)base + text_size);
1604 end_pfn = PFN_UP((unsigned long)base + total_size);
1605 if (end_pfn > begin_pfn)
1606 set_memory_nx(begin_pfn << PAGE_SHIFT, end_pfn - begin_pfn);
1607 }
1608}
1609
1610/* Setting memory back to RW+NX before releasing it */
1611void unset_section_ro_nx(struct module *mod, void *module_region)
1612{
1613 unsigned long total_pages;
1614
1615 if (mod->module_core == module_region) {
1616 /* Set core as NX+RW */
1617 total_pages = MOD_NUMBER_OF_PAGES(mod->module_core, mod->core_size);
1618 set_memory_nx((unsigned long)mod->module_core, total_pages);
1619 set_memory_rw((unsigned long)mod->module_core, total_pages);
1620
1621 } else if (mod->module_init == module_region) {
1622 /* Set init as NX+RW */
1623 total_pages = MOD_NUMBER_OF_PAGES(mod->module_init, mod->init_size);
1624 set_memory_nx((unsigned long)mod->module_init, total_pages);
1625 set_memory_rw((unsigned long)mod->module_init, total_pages);
1626 }
1627}
1628
1629/* Iterate through all modules and set each module's text as RW */
1630void set_all_modules_text_rw()
1631{
1632 struct module *mod;
1633
1634 mutex_lock(&module_mutex);
1635 list_for_each_entry_rcu(mod, &modules, list) {
1636 if ((mod->module_core) && (mod->core_text_size)) {
1637 set_page_attributes(mod->module_core,
1638 mod->module_core + mod->core_text_size,
1639 set_memory_rw);
1640 }
1641 if ((mod->module_init) && (mod->init_text_size)) {
1642 set_page_attributes(mod->module_init,
1643 mod->module_init + mod->init_text_size,
1644 set_memory_rw);
1645 }
1646 }
1647 mutex_unlock(&module_mutex);
1648}
1649
1650/* Iterate through all modules and set each module's text as RO */
1651void set_all_modules_text_ro()
1652{
1653 struct module *mod;
1654
1655 mutex_lock(&module_mutex);
1656 list_for_each_entry_rcu(mod, &modules, list) {
1657 if ((mod->module_core) && (mod->core_text_size)) {
1658 set_page_attributes(mod->module_core,
1659 mod->module_core + mod->core_text_size,
1660 set_memory_ro);
1661 }
1662 if ((mod->module_init) && (mod->init_text_size)) {
1663 set_page_attributes(mod->module_init,
1664 mod->module_init + mod->init_text_size,
1665 set_memory_ro);
1666 }
1667 }
1668 mutex_unlock(&module_mutex);
1669}
1670#else
1671static inline void set_section_ro_nx(void *base, unsigned long text_size, unsigned long ro_size, unsigned long total_size) { }
1672static inline void unset_section_ro_nx(struct module *mod, void *module_region) { }
1673#endif
1674
1675/* Free a module, remove from lists, etc. */
1676static void free_module(struct module *mod)
1677{
1678 trace_module_free(mod);
1679
1680 /* Delete from various lists */
1681 mutex_lock(&module_mutex);
1682 stop_machine(__unlink_module, mod, NULL);
1683 mutex_unlock(&module_mutex);
1684 mod_sysfs_teardown(mod);
1685
1686 /* Remove dynamic debug info */
1687 ddebug_remove_module(mod->name);
1688
1689 /* Arch-specific cleanup. */
1690 module_arch_cleanup(mod);
1691
1692 /* Module unload stuff */
1693 module_unload_free(mod);
1694
1695 /* Free any allocated parameters. */
1696 destroy_params(mod->kp, mod->num_kp);
1697
1698 /* This may be NULL, but that's OK */
1699 unset_section_ro_nx(mod, mod->module_init);
1700 module_free(mod, mod->module_init);
1701 kfree(mod->args);
1702 percpu_modfree(mod);
1703
1704 /* Free lock-classes: */
1705 lockdep_free_key_range(mod->module_core, mod->core_size);
1706
1707 /* Finally, free the core (containing the module structure) */
1708 unset_section_ro_nx(mod, mod->module_core);
1709 module_free(mod, mod->module_core);
1710
1711#ifdef CONFIG_MPU
1712 update_protections(current->mm);
1713#endif
1714}
1715
1716void *__symbol_get(const char *symbol)
1717{
1718 struct module *owner;
1719 const struct kernel_symbol *sym;
1720
1721 preempt_disable();
1722 sym = find_symbol(symbol, &owner, NULL, true, true);
1723 if (sym && strong_try_module_get(owner))
1724 sym = NULL;
1725 preempt_enable();
1726
1727 return sym ? (void *)sym->value : NULL;
1728}
1729EXPORT_SYMBOL_GPL(__symbol_get);
1730
1731/*
1732 * Ensure that an exported symbol [global namespace] does not already exist
1733 * in the kernel or in some other module's exported symbol table.
1734 *
1735 * You must hold the module_mutex.
1736 */
1737static int verify_export_symbols(struct module *mod)
1738{
1739 unsigned int i;
1740 struct module *owner;
1741 const struct kernel_symbol *s;
1742 struct {
1743 const struct kernel_symbol *sym;
1744 unsigned int num;
1745 } arr[] = {
1746 { mod->syms, mod->num_syms },
1747 { mod->gpl_syms, mod->num_gpl_syms },
1748 { mod->gpl_future_syms, mod->num_gpl_future_syms },
1749#ifdef CONFIG_UNUSED_SYMBOLS
1750 { mod->unused_syms, mod->num_unused_syms },
1751 { mod->unused_gpl_syms, mod->num_unused_gpl_syms },
1752#endif
1753 };
1754
1755 for (i = 0; i < ARRAY_SIZE(arr); i++) {
1756 for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
1757 if (find_symbol(s->name, &owner, NULL, true, false)) {
1758 printk(KERN_ERR
1759 "%s: exports duplicate symbol %s"
1760 " (owned by %s)\n",
1761 mod->name, s->name, module_name(owner));
1762 return -ENOEXEC;
1763 }
1764 }
1765 }
1766 return 0;
1767}
1768
1769/* Change all symbols so that st_value encodes the pointer directly. */
1770static int simplify_symbols(struct module *mod, const struct load_info *info)
1771{
1772 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
1773 Elf_Sym *sym = (void *)symsec->sh_addr;
1774 unsigned long secbase;
1775 unsigned int i;
1776 int ret = 0;
1777 const struct kernel_symbol *ksym;
1778
1779 for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
1780 const char *name = info->strtab + sym[i].st_name;
1781
1782 switch (sym[i].st_shndx) {
1783 case SHN_COMMON:
1784 /* We compiled with -fno-common. These are not
1785 supposed to happen. */
1786 DEBUGP("Common symbol: %s\n", name);
1787 printk("%s: please compile with -fno-common\n",
1788 mod->name);
1789 ret = -ENOEXEC;
1790 break;
1791
1792 case SHN_ABS:
1793 /* Don't need to do anything */
1794 DEBUGP("Absolute symbol: 0x%08lx\n",
1795 (long)sym[i].st_value);
1796 break;
1797
1798 case SHN_UNDEF:
1799 ksym = resolve_symbol_wait(mod, info, name);
1800 /* Ok if resolved. */
1801 if (ksym && !IS_ERR(ksym)) {
1802 sym[i].st_value = ksym->value;
1803 break;
1804 }
1805
1806 /* Ok if weak. */
1807 if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
1808 break;
1809
1810 printk(KERN_WARNING "%s: Unknown symbol %s (err %li)\n",
1811 mod->name, name, PTR_ERR(ksym));
1812 ret = PTR_ERR(ksym) ?: -ENOENT;
1813 break;
1814
1815 default:
1816 /* Divert to percpu allocation if a percpu var. */
1817 if (sym[i].st_shndx == info->index.pcpu)
1818 secbase = (unsigned long)mod_percpu(mod);
1819 else
1820 secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
1821 sym[i].st_value += secbase;
1822 break;
1823 }
1824 }
1825
1826 return ret;
1827}
1828
1829static int apply_relocations(struct module *mod, const struct load_info *info)
1830{
1831 unsigned int i;
1832 int err = 0;
1833
1834 /* Now do relocations. */
1835 for (i = 1; i < info->hdr->e_shnum; i++) {
1836 unsigned int infosec = info->sechdrs[i].sh_info;
1837
1838 /* Not a valid relocation section? */
1839 if (infosec >= info->hdr->e_shnum)
1840 continue;
1841
1842 /* Don't bother with non-allocated sections */
1843 if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
1844 continue;
1845
1846 if (info->sechdrs[i].sh_type == SHT_REL)
1847 err = apply_relocate(info->sechdrs, info->strtab,
1848 info->index.sym, i, mod);
1849 else if (info->sechdrs[i].sh_type == SHT_RELA)
1850 err = apply_relocate_add(info->sechdrs, info->strtab,
1851 info->index.sym, i, mod);
1852 if (err < 0)
1853 break;
1854 }
1855 return err;
1856}
1857
1858/* Additional bytes needed by arch in front of individual sections */
1859unsigned int __weak arch_mod_section_prepend(struct module *mod,
1860 unsigned int section)
1861{
1862 /* default implementation just returns zero */
1863 return 0;
1864}
1865
1866/* Update size with this section: return offset. */
1867static long get_offset(struct module *mod, unsigned int *size,
1868 Elf_Shdr *sechdr, unsigned int section)
1869{
1870 long ret;
1871
1872 *size += arch_mod_section_prepend(mod, section);
1873 ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
1874 *size = ret + sechdr->sh_size;
1875 return ret;
1876}
1877
1878/* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
1879 might -- code, read-only data, read-write data, small data. Tally
1880 sizes, and place the offsets into sh_entsize fields: high bit means it
1881 belongs in init. */
1882static void layout_sections(struct module *mod, struct load_info *info)
1883{
1884 static unsigned long const masks[][2] = {
1885 /* NOTE: all executable code must be the first section
1886 * in this array; otherwise modify the text_size
1887 * finder in the two loops below */
1888 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
1889 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
1890 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
1891 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
1892 };
1893 unsigned int m, i;
1894
1895 for (i = 0; i < info->hdr->e_shnum; i++)
1896 info->sechdrs[i].sh_entsize = ~0UL;
1897
1898 DEBUGP("Core section allocation order:\n");
1899 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
1900 for (i = 0; i < info->hdr->e_shnum; ++i) {
1901 Elf_Shdr *s = &info->sechdrs[i];
1902 const char *sname = info->secstrings + s->sh_name;
1903
1904 if ((s->sh_flags & masks[m][0]) != masks[m][0]
1905 || (s->sh_flags & masks[m][1])
1906 || s->sh_entsize != ~0UL
1907 || strstarts(sname, ".init"))
1908 continue;
1909 s->sh_entsize = get_offset(mod, &mod->core_size, s, i);
1910 DEBUGP("\t%s\n", name);
1911 }
1912 switch (m) {
1913 case 0: /* executable */
1914 mod->core_size = debug_align(mod->core_size);
1915 mod->core_text_size = mod->core_size;
1916 break;
1917 case 1: /* RO: text and ro-data */
1918 mod->core_size = debug_align(mod->core_size);
1919 mod->core_ro_size = mod->core_size;
1920 break;
1921 case 3: /* whole core */
1922 mod->core_size = debug_align(mod->core_size);
1923 break;
1924 }
1925 }
1926
1927 DEBUGP("Init section allocation order:\n");
1928 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
1929 for (i = 0; i < info->hdr->e_shnum; ++i) {
1930 Elf_Shdr *s = &info->sechdrs[i];
1931 const char *sname = info->secstrings + s->sh_name;
1932
1933 if ((s->sh_flags & masks[m][0]) != masks[m][0]
1934 || (s->sh_flags & masks[m][1])
1935 || s->sh_entsize != ~0UL
1936 || !strstarts(sname, ".init"))
1937 continue;
1938 s->sh_entsize = (get_offset(mod, &mod->init_size, s, i)
1939 | INIT_OFFSET_MASK);
1940 DEBUGP("\t%s\n", sname);
1941 }
1942 switch (m) {
1943 case 0: /* executable */
1944 mod->init_size = debug_align(mod->init_size);
1945 mod->init_text_size = mod->init_size;
1946 break;
1947 case 1: /* RO: text and ro-data */
1948 mod->init_size = debug_align(mod->init_size);
1949 mod->init_ro_size = mod->init_size;
1950 break;
1951 case 3: /* whole init */
1952 mod->init_size = debug_align(mod->init_size);
1953 break;
1954 }
1955 }
1956}
1957
1958static void set_license(struct module *mod, const char *license)
1959{
1960 if (!license)
1961 license = "unspecified";
1962
1963 if (!license_is_gpl_compatible(license)) {
1964 if (!test_taint(TAINT_PROPRIETARY_MODULE))
1965 printk(KERN_WARNING "%s: module license '%s' taints "
1966 "kernel.\n", mod->name, license);
1967 add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
1968 }
1969}
1970
1971/* Parse tag=value strings from .modinfo section */
1972static char *next_string(char *string, unsigned long *secsize)
1973{
1974 /* Skip non-zero chars */
1975 while (string[0]) {
1976 string++;
1977 if ((*secsize)-- <= 1)
1978 return NULL;
1979 }
1980
1981 /* Skip any zero padding. */
1982 while (!string[0]) {
1983 string++;
1984 if ((*secsize)-- <= 1)
1985 return NULL;
1986 }
1987 return string;
1988}
1989
1990static char *get_modinfo(struct load_info *info, const char *tag)
1991{
1992 char *p;
1993 unsigned int taglen = strlen(tag);
1994 Elf_Shdr *infosec = &info->sechdrs[info->index.info];
1995 unsigned long size = infosec->sh_size;
1996
1997 for (p = (char *)infosec->sh_addr; p; p = next_string(p, &size)) {
1998 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
1999 return p + taglen + 1;
2000 }
2001 return NULL;
2002}
2003
2004static void setup_modinfo(struct module *mod, struct load_info *info)
2005{
2006 struct module_attribute *attr;
2007 int i;
2008
2009 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2010 if (attr->setup)
2011 attr->setup(mod, get_modinfo(info, attr->attr.name));
2012 }
2013}
2014
2015static void free_modinfo(struct module *mod)
2016{
2017 struct module_attribute *attr;
2018 int i;
2019
2020 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2021 if (attr->free)
2022 attr->free(mod);
2023 }
2024}
2025
2026#ifdef CONFIG_KALLSYMS
2027
2028/* lookup symbol in given range of kernel_symbols */
2029static const struct kernel_symbol *lookup_symbol(const char *name,
2030 const struct kernel_symbol *start,
2031 const struct kernel_symbol *stop)
2032{
2033 const struct kernel_symbol *ks = start;
2034 for (; ks < stop; ks++)
2035 if (strcmp(ks->name, name) == 0)
2036 return ks;
2037 return NULL;
2038}
2039
2040static int is_exported(const char *name, unsigned long value,
2041 const struct module *mod)
2042{
2043 const struct kernel_symbol *ks;
2044 if (!mod)
2045 ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
2046 else
2047 ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
2048 return ks != NULL && ks->value == value;
2049}
2050
2051/* As per nm */
2052static char elf_type(const Elf_Sym *sym, const struct load_info *info)
2053{
2054 const Elf_Shdr *sechdrs = info->sechdrs;
2055
2056 if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
2057 if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
2058 return 'v';
2059 else
2060 return 'w';
2061 }
2062 if (sym->st_shndx == SHN_UNDEF)
2063 return 'U';
2064 if (sym->st_shndx == SHN_ABS)
2065 return 'a';
2066 if (sym->st_shndx >= SHN_LORESERVE)
2067 return '?';
2068 if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
2069 return 't';
2070 if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
2071 && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
2072 if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
2073 return 'r';
2074 else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2075 return 'g';
2076 else
2077 return 'd';
2078 }
2079 if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
2080 if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2081 return 's';
2082 else
2083 return 'b';
2084 }
2085 if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
2086 ".debug")) {
2087 return 'n';
2088 }
2089 return '?';
2090}
2091
2092static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
2093 unsigned int shnum)
2094{
2095 const Elf_Shdr *sec;
2096
2097 if (src->st_shndx == SHN_UNDEF
2098 || src->st_shndx >= shnum
2099 || !src->st_name)
2100 return false;
2101
2102 sec = sechdrs + src->st_shndx;
2103 if (!(sec->sh_flags & SHF_ALLOC)
2104#ifndef CONFIG_KALLSYMS_ALL
2105 || !(sec->sh_flags & SHF_EXECINSTR)
2106#endif
2107 || (sec->sh_entsize & INIT_OFFSET_MASK))
2108 return false;
2109
2110 return true;
2111}
2112
2113static void layout_symtab(struct module *mod, struct load_info *info)
2114{
2115 Elf_Shdr *symsect = info->sechdrs + info->index.sym;
2116 Elf_Shdr *strsect = info->sechdrs + info->index.str;
2117 const Elf_Sym *src;
2118 unsigned int i, nsrc, ndst;
2119
2120 /* Put symbol section at end of init part of module. */
2121 symsect->sh_flags |= SHF_ALLOC;
2122 symsect->sh_entsize = get_offset(mod, &mod->init_size, symsect,
2123 info->index.sym) | INIT_OFFSET_MASK;
2124 DEBUGP("\t%s\n", info->secstrings + symsect->sh_name);
2125
2126 src = (void *)info->hdr + symsect->sh_offset;
2127 nsrc = symsect->sh_size / sizeof(*src);
2128 for (ndst = i = 1; i < nsrc; ++i, ++src)
2129 if (is_core_symbol(src, info->sechdrs, info->hdr->e_shnum)) {
2130 unsigned int j = src->st_name;
2131
2132 while (!__test_and_set_bit(j, info->strmap)
2133 && info->strtab[j])
2134 ++j;
2135 ++ndst;
2136 }
2137
2138 /* Append room for core symbols at end of core part. */
2139 info->symoffs = ALIGN(mod->core_size, symsect->sh_addralign ?: 1);
2140 mod->core_size = info->symoffs + ndst * sizeof(Elf_Sym);
2141
2142 /* Put string table section at end of init part of module. */
2143 strsect->sh_flags |= SHF_ALLOC;
2144 strsect->sh_entsize = get_offset(mod, &mod->init_size, strsect,
2145 info->index.str) | INIT_OFFSET_MASK;
2146 DEBUGP("\t%s\n", info->secstrings + strsect->sh_name);
2147
2148 /* Append room for core symbols' strings at end of core part. */
2149 info->stroffs = mod->core_size;
2150 __set_bit(0, info->strmap);
2151 mod->core_size += bitmap_weight(info->strmap, strsect->sh_size);
2152}
2153
2154static void add_kallsyms(struct module *mod, const struct load_info *info)
2155{
2156 unsigned int i, ndst;
2157 const Elf_Sym *src;
2158 Elf_Sym *dst;
2159 char *s;
2160 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2161
2162 mod->symtab = (void *)symsec->sh_addr;
2163 mod->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
2164 /* Make sure we get permanent strtab: don't use info->strtab. */
2165 mod->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
2166
2167 /* Set types up while we still have access to sections. */
2168 for (i = 0; i < mod->num_symtab; i++)
2169 mod->symtab[i].st_info = elf_type(&mod->symtab[i], info);
2170
2171 mod->core_symtab = dst = mod->module_core + info->symoffs;
2172 src = mod->symtab;
2173 *dst = *src;
2174 for (ndst = i = 1; i < mod->num_symtab; ++i, ++src) {
2175 if (!is_core_symbol(src, info->sechdrs, info->hdr->e_shnum))
2176 continue;
2177 dst[ndst] = *src;
2178 dst[ndst].st_name = bitmap_weight(info->strmap,
2179 dst[ndst].st_name);
2180 ++ndst;
2181 }
2182 mod->core_num_syms = ndst;
2183
2184 mod->core_strtab = s = mod->module_core + info->stroffs;
2185 for (*s = 0, i = 1; i < info->sechdrs[info->index.str].sh_size; ++i)
2186 if (test_bit(i, info->strmap))
2187 *++s = mod->strtab[i];
2188}
2189#else
2190static inline void layout_symtab(struct module *mod, struct load_info *info)
2191{
2192}
2193
2194static void add_kallsyms(struct module *mod, const struct load_info *info)
2195{
2196}
2197#endif /* CONFIG_KALLSYMS */
2198
2199static void dynamic_debug_setup(struct _ddebug *debug, unsigned int num)
2200{
2201 if (!debug)
2202 return;
2203#ifdef CONFIG_DYNAMIC_DEBUG
2204 if (ddebug_add_module(debug, num, debug->modname))
2205 printk(KERN_ERR "dynamic debug error adding module: %s\n",
2206 debug->modname);
2207#endif
2208}
2209
2210static void dynamic_debug_remove(struct _ddebug *debug)
2211{
2212 if (debug)
2213 ddebug_remove_module(debug->modname);
2214}
2215
2216static void *module_alloc_update_bounds(unsigned long size)
2217{
2218 void *ret = module_alloc(size);
2219
2220 if (ret) {
2221 mutex_lock(&module_mutex);
2222 /* Update module bounds. */
2223 if ((unsigned long)ret < module_addr_min)
2224 module_addr_min = (unsigned long)ret;
2225 if ((unsigned long)ret + size > module_addr_max)
2226 module_addr_max = (unsigned long)ret + size;
2227 mutex_unlock(&module_mutex);
2228 }
2229 return ret;
2230}
2231
2232#ifdef CONFIG_DEBUG_KMEMLEAK
2233static void kmemleak_load_module(const struct module *mod,
2234 const struct load_info *info)
2235{
2236 unsigned int i;
2237
2238 /* only scan the sections containing data */
2239 kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
2240
2241 for (i = 1; i < info->hdr->e_shnum; i++) {
2242 const char *name = info->secstrings + info->sechdrs[i].sh_name;
2243 if (!(info->sechdrs[i].sh_flags & SHF_ALLOC))
2244 continue;
2245 if (!strstarts(name, ".data") && !strstarts(name, ".bss"))
2246 continue;
2247
2248 kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
2249 info->sechdrs[i].sh_size, GFP_KERNEL);
2250 }
2251}
2252#else
2253static inline void kmemleak_load_module(const struct module *mod,
2254 const struct load_info *info)
2255{
2256}
2257#endif
2258
2259/* Sets info->hdr and info->len. */
2260static int copy_and_check(struct load_info *info,
2261 const void __user *umod, unsigned long len,
2262 const char __user *uargs)
2263{
2264 int err;
2265 Elf_Ehdr *hdr;
2266
2267 if (len < sizeof(*hdr))
2268 return -ENOEXEC;
2269
2270 /* Suck in entire file: we'll want most of it. */
2271 /* vmalloc barfs on "unusual" numbers. Check here */
2272 if (len > 64 * 1024 * 1024 || (hdr = vmalloc(len)) == NULL)
2273 return -ENOMEM;
2274
2275 if (copy_from_user(hdr, umod, len) != 0) {
2276 err = -EFAULT;
2277 goto free_hdr;
2278 }
2279
2280 /* Sanity checks against insmoding binaries or wrong arch,
2281 weird elf version */
2282 if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0
2283 || hdr->e_type != ET_REL
2284 || !elf_check_arch(hdr)
2285 || hdr->e_shentsize != sizeof(Elf_Shdr)) {
2286 err = -ENOEXEC;
2287 goto free_hdr;
2288 }
2289
2290 if (len < hdr->e_shoff + hdr->e_shnum * sizeof(Elf_Shdr)) {
2291 err = -ENOEXEC;
2292 goto free_hdr;
2293 }
2294
2295 info->hdr = hdr;
2296 info->len = len;
2297 return 0;
2298
2299free_hdr:
2300 vfree(hdr);
2301 return err;
2302}
2303
2304static void free_copy(struct load_info *info)
2305{
2306 vfree(info->hdr);
2307}
2308
2309static int rewrite_section_headers(struct load_info *info)
2310{
2311 unsigned int i;
2312
2313 /* This should always be true, but let's be sure. */
2314 info->sechdrs[0].sh_addr = 0;
2315
2316 for (i = 1; i < info->hdr->e_shnum; i++) {
2317 Elf_Shdr *shdr = &info->sechdrs[i];
2318 if (shdr->sh_type != SHT_NOBITS
2319 && info->len < shdr->sh_offset + shdr->sh_size) {
2320 printk(KERN_ERR "Module len %lu truncated\n",
2321 info->len);
2322 return -ENOEXEC;
2323 }
2324
2325 /* Mark all sections sh_addr with their address in the
2326 temporary image. */
2327 shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
2328
2329#ifndef CONFIG_MODULE_UNLOAD
2330 /* Don't load .exit sections */
2331 if (strstarts(info->secstrings+shdr->sh_name, ".exit"))
2332 shdr->sh_flags &= ~(unsigned long)SHF_ALLOC;
2333#endif
2334 }
2335
2336 /* Track but don't keep modinfo and version sections. */
2337 info->index.vers = find_sec(info, "__versions");
2338 info->index.info = find_sec(info, ".modinfo");
2339 info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
2340 info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
2341 return 0;
2342}
2343
2344/*
2345 * Set up our basic convenience variables (pointers to section headers,
2346 * search for module section index etc), and do some basic section
2347 * verification.
2348 *
2349 * Return the temporary module pointer (we'll replace it with the final
2350 * one when we move the module sections around).
2351 */
2352static struct module *setup_load_info(struct load_info *info)
2353{
2354 unsigned int i;
2355 int err;
2356 struct module *mod;
2357
2358 /* Set up the convenience variables */
2359 info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
2360 info->secstrings = (void *)info->hdr
2361 + info->sechdrs[info->hdr->e_shstrndx].sh_offset;
2362
2363 err = rewrite_section_headers(info);
2364 if (err)
2365 return ERR_PTR(err);
2366
2367 /* Find internal symbols and strings. */
2368 for (i = 1; i < info->hdr->e_shnum; i++) {
2369 if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
2370 info->index.sym = i;
2371 info->index.str = info->sechdrs[i].sh_link;
2372 info->strtab = (char *)info->hdr
2373 + info->sechdrs[info->index.str].sh_offset;
2374 break;
2375 }
2376 }
2377
2378 info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
2379 if (!info->index.mod) {
2380 printk(KERN_WARNING "No module found in object\n");
2381 return ERR_PTR(-ENOEXEC);
2382 }
2383 /* This is temporary: point mod into copy of data. */
2384 mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2385
2386 if (info->index.sym == 0) {
2387 printk(KERN_WARNING "%s: module has no symbols (stripped?)\n",
2388 mod->name);
2389 return ERR_PTR(-ENOEXEC);
2390 }
2391
2392 info->index.pcpu = find_pcpusec(info);
2393
2394 /* Check module struct version now, before we try to use module. */
2395 if (!check_modstruct_version(info->sechdrs, info->index.vers, mod))
2396 return ERR_PTR(-ENOEXEC);
2397
2398 return mod;
2399}
2400
2401static int check_modinfo(struct module *mod, struct load_info *info)
2402{
2403 const char *modmagic = get_modinfo(info, "vermagic");
2404 int err;
2405
2406 /* This is allowed: modprobe --force will invalidate it. */
2407 if (!modmagic) {
2408 err = try_to_force_load(mod, "bad vermagic");
2409 if (err)
2410 return err;
2411 } else if (!same_magic(modmagic, vermagic, info->index.vers)) {
2412 printk(KERN_ERR "%s: version magic '%s' should be '%s'\n",
2413 mod->name, modmagic, vermagic);
2414 return -ENOEXEC;
2415 }
2416
2417 if (get_modinfo(info, "staging")) {
2418 add_taint_module(mod, TAINT_CRAP);
2419 printk(KERN_WARNING "%s: module is from the staging directory,"
2420 " the quality is unknown, you have been warned.\n",
2421 mod->name);
2422 }
2423
2424 /* Set up license info based on the info section */
2425 set_license(mod, get_modinfo(info, "license"));
2426
2427 return 0;
2428}
2429
2430static void find_module_sections(struct module *mod, struct load_info *info)
2431{
2432 mod->kp = section_objs(info, "__param",
2433 sizeof(*mod->kp), &mod->num_kp);
2434 mod->syms = section_objs(info, "__ksymtab",
2435 sizeof(*mod->syms), &mod->num_syms);
2436 mod->crcs = section_addr(info, "__kcrctab");
2437 mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
2438 sizeof(*mod->gpl_syms),
2439 &mod->num_gpl_syms);
2440 mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
2441 mod->gpl_future_syms = section_objs(info,
2442 "__ksymtab_gpl_future",
2443 sizeof(*mod->gpl_future_syms),
2444 &mod->num_gpl_future_syms);
2445 mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future");
2446
2447#ifdef CONFIG_UNUSED_SYMBOLS
2448 mod->unused_syms = section_objs(info, "__ksymtab_unused",
2449 sizeof(*mod->unused_syms),
2450 &mod->num_unused_syms);
2451 mod->unused_crcs = section_addr(info, "__kcrctab_unused");
2452 mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl",
2453 sizeof(*mod->unused_gpl_syms),
2454 &mod->num_unused_gpl_syms);
2455 mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl");
2456#endif
2457#ifdef CONFIG_CONSTRUCTORS
2458 mod->ctors = section_objs(info, ".ctors",
2459 sizeof(*mod->ctors), &mod->num_ctors);
2460#endif
2461
2462#ifdef CONFIG_TRACEPOINTS
2463 mod->tracepoints = section_objs(info, "__tracepoints",
2464 sizeof(*mod->tracepoints),
2465 &mod->num_tracepoints);
2466#endif
2467#ifdef HAVE_JUMP_LABEL
2468 mod->jump_entries = section_objs(info, "__jump_table",
2469 sizeof(*mod->jump_entries),
2470 &mod->num_jump_entries);
2471#endif
2472#ifdef CONFIG_EVENT_TRACING
2473 mod->trace_events = section_objs(info, "_ftrace_events",
2474 sizeof(*mod->trace_events),
2475 &mod->num_trace_events);
2476 /*
2477 * This section contains pointers to allocated objects in the trace
2478 * code and not scanning it leads to false positives.
2479 */
2480 kmemleak_scan_area(mod->trace_events, sizeof(*mod->trace_events) *
2481 mod->num_trace_events, GFP_KERNEL);
2482#endif
2483#ifdef CONFIG_TRACING
2484 mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
2485 sizeof(*mod->trace_bprintk_fmt_start),
2486 &mod->num_trace_bprintk_fmt);
2487 /*
2488 * This section contains pointers to allocated objects in the trace
2489 * code and not scanning it leads to false positives.
2490 */
2491 kmemleak_scan_area(mod->trace_bprintk_fmt_start,
2492 sizeof(*mod->trace_bprintk_fmt_start) *
2493 mod->num_trace_bprintk_fmt, GFP_KERNEL);
2494#endif
2495#ifdef CONFIG_FTRACE_MCOUNT_RECORD
2496 /* sechdrs[0].sh_size is always zero */
2497 mod->ftrace_callsites = section_objs(info, "__mcount_loc",
2498 sizeof(*mod->ftrace_callsites),
2499 &mod->num_ftrace_callsites);
2500#endif
2501
2502 mod->extable = section_objs(info, "__ex_table",
2503 sizeof(*mod->extable), &mod->num_exentries);
2504
2505 if (section_addr(info, "__obsparm"))
2506 printk(KERN_WARNING "%s: Ignoring obsolete parameters\n",
2507 mod->name);
2508
2509 info->debug = section_objs(info, "__verbose",
2510 sizeof(*info->debug), &info->num_debug);
2511}
2512
2513static int move_module(struct module *mod, struct load_info *info)
2514{
2515 int i;
2516 void *ptr;
2517
2518 /* Do the allocs. */
2519 ptr = module_alloc_update_bounds(mod->core_size);
2520 /*
2521 * The pointer to this block is stored in the module structure
2522 * which is inside the block. Just mark it as not being a
2523 * leak.
2524 */
2525 kmemleak_not_leak(ptr);
2526 if (!ptr)
2527 return -ENOMEM;
2528
2529 memset(ptr, 0, mod->core_size);
2530 mod->module_core = ptr;
2531
2532 ptr = module_alloc_update_bounds(mod->init_size);
2533 /*
2534 * The pointer to this block is stored in the module structure
2535 * which is inside the block. This block doesn't need to be
2536 * scanned as it contains data and code that will be freed
2537 * after the module is initialized.
2538 */
2539 kmemleak_ignore(ptr);
2540 if (!ptr && mod->init_size) {
2541 module_free(mod, mod->module_core);
2542 return -ENOMEM;
2543 }
2544 memset(ptr, 0, mod->init_size);
2545 mod->module_init = ptr;
2546
2547 /* Transfer each section which specifies SHF_ALLOC */
2548 DEBUGP("final section addresses:\n");
2549 for (i = 0; i < info->hdr->e_shnum; i++) {
2550 void *dest;
2551 Elf_Shdr *shdr = &info->sechdrs[i];
2552
2553 if (!(shdr->sh_flags & SHF_ALLOC))
2554 continue;
2555
2556 if (shdr->sh_entsize & INIT_OFFSET_MASK)
2557 dest = mod->module_init
2558 + (shdr->sh_entsize & ~INIT_OFFSET_MASK);
2559 else
2560 dest = mod->module_core + shdr->sh_entsize;
2561
2562 if (shdr->sh_type != SHT_NOBITS)
2563 memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
2564 /* Update sh_addr to point to copy in image. */
2565 shdr->sh_addr = (unsigned long)dest;
2566 DEBUGP("\t0x%lx %s\n",
2567 shdr->sh_addr, info->secstrings + shdr->sh_name);
2568 }
2569
2570 return 0;
2571}
2572
2573static int check_module_license_and_versions(struct module *mod)
2574{
2575 /*
2576 * ndiswrapper is under GPL by itself, but loads proprietary modules.
2577 * Don't use add_taint_module(), as it would prevent ndiswrapper from
2578 * using GPL-only symbols it needs.
2579 */
2580 if (strcmp(mod->name, "ndiswrapper") == 0)
2581 add_taint(TAINT_PROPRIETARY_MODULE);
2582
2583 /* driverloader was caught wrongly pretending to be under GPL */
2584 if (strcmp(mod->name, "driverloader") == 0)
2585 add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
2586
2587#ifdef CONFIG_MODVERSIONS
2588 if ((mod->num_syms && !mod->crcs)
2589 || (mod->num_gpl_syms && !mod->gpl_crcs)
2590 || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
2591#ifdef CONFIG_UNUSED_SYMBOLS
2592 || (mod->num_unused_syms && !mod->unused_crcs)
2593 || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
2594#endif
2595 ) {
2596 return try_to_force_load(mod,
2597 "no versions for exported symbols");
2598 }
2599#endif
2600 return 0;
2601}
2602
2603static void flush_module_icache(const struct module *mod)
2604{
2605 mm_segment_t old_fs;
2606
2607 /* flush the icache in correct context */
2608 old_fs = get_fs();
2609 set_fs(KERNEL_DS);
2610
2611 /*
2612 * Flush the instruction cache, since we've played with text.
2613 * Do it before processing of module parameters, so the module
2614 * can provide parameter accessor functions of its own.
2615 */
2616 if (mod->module_init)
2617 flush_icache_range((unsigned long)mod->module_init,
2618 (unsigned long)mod->module_init
2619 + mod->init_size);
2620 flush_icache_range((unsigned long)mod->module_core,
2621 (unsigned long)mod->module_core + mod->core_size);
2622
2623 set_fs(old_fs);
2624}
2625
2626static struct module *layout_and_allocate(struct load_info *info)
2627{
2628 /* Module within temporary copy. */
2629 struct module *mod;
2630 Elf_Shdr *pcpusec;
2631 int err;
2632
2633 mod = setup_load_info(info);
2634 if (IS_ERR(mod))
2635 return mod;
2636
2637 err = check_modinfo(mod, info);
2638 if (err)
2639 return ERR_PTR(err);
2640
2641 /* Allow arches to frob section contents and sizes. */
2642 err = module_frob_arch_sections(info->hdr, info->sechdrs,
2643 info->secstrings, mod);
2644 if (err < 0)
2645 goto out;
2646
2647 pcpusec = &info->sechdrs[info->index.pcpu];
2648 if (pcpusec->sh_size) {
2649 /* We have a special allocation for this section. */
2650 err = percpu_modalloc(mod,
2651 pcpusec->sh_size, pcpusec->sh_addralign);
2652 if (err)
2653 goto out;
2654 pcpusec->sh_flags &= ~(unsigned long)SHF_ALLOC;
2655 }
2656
2657 /* Determine total sizes, and put offsets in sh_entsize. For now
2658 this is done generically; there doesn't appear to be any
2659 special cases for the architectures. */
2660 layout_sections(mod, info);
2661
2662 info->strmap = kzalloc(BITS_TO_LONGS(info->sechdrs[info->index.str].sh_size)
2663 * sizeof(long), GFP_KERNEL);
2664 if (!info->strmap) {
2665 err = -ENOMEM;
2666 goto free_percpu;
2667 }
2668 layout_symtab(mod, info);
2669
2670 /* Allocate and move to the final place */
2671 err = move_module(mod, info);
2672 if (err)
2673 goto free_strmap;
2674
2675 /* Module has been copied to its final place now: return it. */
2676 mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2677 kmemleak_load_module(mod, info);
2678 return mod;
2679
2680free_strmap:
2681 kfree(info->strmap);
2682free_percpu:
2683 percpu_modfree(mod);
2684out:
2685 return ERR_PTR(err);
2686}
2687
2688/* mod is no longer valid after this! */
2689static void module_deallocate(struct module *mod, struct load_info *info)
2690{
2691 kfree(info->strmap);
2692 percpu_modfree(mod);
2693 module_free(mod, mod->module_init);
2694 module_free(mod, mod->module_core);
2695}
2696
2697static int post_relocation(struct module *mod, const struct load_info *info)
2698{
2699 /* Sort exception table now relocations are done. */
2700 sort_extable(mod->extable, mod->extable + mod->num_exentries);
2701
2702 /* Copy relocated percpu area over. */
2703 percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
2704 info->sechdrs[info->index.pcpu].sh_size);
2705
2706 /* Setup kallsyms-specific fields. */
2707 add_kallsyms(mod, info);
2708
2709 /* Arch-specific module finalizing. */
2710 return module_finalize(info->hdr, info->sechdrs, mod);
2711}
2712
2713/* Allocate and load the module: note that size of section 0 is always
2714 zero, and we rely on this for optional sections. */
2715static struct module *load_module(void __user *umod,
2716 unsigned long len,
2717 const char __user *uargs)
2718{
2719 struct load_info info = { NULL, };
2720 struct module *mod;
2721 long err;
2722
2723 DEBUGP("load_module: umod=%p, len=%lu, uargs=%p\n",
2724 umod, len, uargs);
2725
2726 /* Copy in the blobs from userspace, check they are vaguely sane. */
2727 err = copy_and_check(&info, umod, len, uargs);
2728 if (err)
2729 return ERR_PTR(err);
2730
2731 /* Figure out module layout, and allocate all the memory. */
2732 mod = layout_and_allocate(&info);
2733 if (IS_ERR(mod)) {
2734 err = PTR_ERR(mod);
2735 goto free_copy;
2736 }
2737
2738 /* Now module is in final location, initialize linked lists, etc. */
2739 err = module_unload_init(mod);
2740 if (err)
2741 goto free_module;
2742
2743 /* Now we've got everything in the final locations, we can
2744 * find optional sections. */
2745 find_module_sections(mod, &info);
2746
2747 err = check_module_license_and_versions(mod);
2748 if (err)
2749 goto free_unload;
2750
2751 /* Set up MODINFO_ATTR fields */
2752 setup_modinfo(mod, &info);
2753
2754 /* Fix up syms, so that st_value is a pointer to location. */
2755 err = simplify_symbols(mod, &info);
2756 if (err < 0)
2757 goto free_modinfo;
2758
2759 err = apply_relocations(mod, &info);
2760 if (err < 0)
2761 goto free_modinfo;
2762
2763 err = post_relocation(mod, &info);
2764 if (err < 0)
2765 goto free_modinfo;
2766
2767 flush_module_icache(mod);
2768
2769 /* Now copy in args */
2770 mod->args = strndup_user(uargs, ~0UL >> 1);
2771 if (IS_ERR(mod->args)) {
2772 err = PTR_ERR(mod->args);
2773 goto free_arch_cleanup;
2774 }
2775
2776 /* Mark state as coming so strong_try_module_get() ignores us. */
2777 mod->state = MODULE_STATE_COMING;
2778
2779 /* Now sew it into the lists so we can get lockdep and oops
2780 * info during argument parsing. Noone should access us, since
2781 * strong_try_module_get() will fail.
2782 * lockdep/oops can run asynchronous, so use the RCU list insertion
2783 * function to insert in a way safe to concurrent readers.
2784 * The mutex protects against concurrent writers.
2785 */
2786 mutex_lock(&module_mutex);
2787 if (find_module(mod->name)) {
2788 err = -EEXIST;
2789 goto unlock;
2790 }
2791
2792 /* This has to be done once we're sure module name is unique. */
2793 if (!mod->taints)
2794 dynamic_debug_setup(info.debug, info.num_debug);
2795
2796 /* Find duplicate symbols */
2797 err = verify_export_symbols(mod);
2798 if (err < 0)
2799 goto ddebug;
2800
2801 module_bug_finalize(info.hdr, info.sechdrs, mod);
2802 list_add_rcu(&mod->list, &modules);
2803 mutex_unlock(&module_mutex);
2804
2805 /* Module is ready to execute: parsing args may do that. */
2806 err = parse_args(mod->name, mod->args, mod->kp, mod->num_kp, NULL);
2807 if (err < 0)
2808 goto unlink;
2809
2810 /* Link in to syfs. */
2811 err = mod_sysfs_setup(mod, &info, mod->kp, mod->num_kp);
2812 if (err < 0)
2813 goto unlink;
2814
2815 /* Get rid of temporary copy and strmap. */
2816 kfree(info.strmap);
2817 free_copy(&info);
2818
2819 /* Done! */
2820 trace_module_load(mod);
2821 return mod;
2822
2823 unlink:
2824 mutex_lock(&module_mutex);
2825 /* Unlink carefully: kallsyms could be walking list. */
2826 list_del_rcu(&mod->list);
2827 module_bug_cleanup(mod);
2828
2829 ddebug:
2830 if (!mod->taints)
2831 dynamic_debug_remove(info.debug);
2832 unlock:
2833 mutex_unlock(&module_mutex);
2834 synchronize_sched();
2835 kfree(mod->args);
2836 free_arch_cleanup:
2837 module_arch_cleanup(mod);
2838 free_modinfo:
2839 free_modinfo(mod);
2840 free_unload:
2841 module_unload_free(mod);
2842 free_module:
2843 module_deallocate(mod, &info);
2844 free_copy:
2845 free_copy(&info);
2846 return ERR_PTR(err);
2847}
2848
2849/* Call module constructors. */
2850static void do_mod_ctors(struct module *mod)
2851{
2852#ifdef CONFIG_CONSTRUCTORS
2853 unsigned long i;
2854
2855 for (i = 0; i < mod->num_ctors; i++)
2856 mod->ctors[i]();
2857#endif
2858}
2859
2860/* This is where the real work happens */
2861SYSCALL_DEFINE3(init_module, void __user *, umod,
2862 unsigned long, len, const char __user *, uargs)
2863{
2864 struct module *mod;
2865 int ret = 0;
2866
2867 /* Must have permission */
2868 if (!capable(CAP_SYS_MODULE) || modules_disabled)
2869 return -EPERM;
2870
2871 /* Do all the hard work */
2872 mod = load_module(umod, len, uargs);
2873 if (IS_ERR(mod))
2874 return PTR_ERR(mod);
2875
2876 blocking_notifier_call_chain(&module_notify_list,
2877 MODULE_STATE_COMING, mod);
2878
2879 /* Set RO and NX regions for core */
2880 set_section_ro_nx(mod->module_core,
2881 mod->core_text_size,
2882 mod->core_ro_size,
2883 mod->core_size);
2884
2885 /* Set RO and NX regions for init */
2886 set_section_ro_nx(mod->module_init,
2887 mod->init_text_size,
2888 mod->init_ro_size,
2889 mod->init_size);
2890
2891 do_mod_ctors(mod);
2892 /* Start the module */
2893 if (mod->init != NULL)
2894 ret = do_one_initcall(mod->init);
2895 if (ret < 0) {
2896 /* Init routine failed: abort. Try to protect us from
2897 buggy refcounters. */
2898 mod->state = MODULE_STATE_GOING;
2899 synchronize_sched();
2900 module_put(mod);
2901 blocking_notifier_call_chain(&module_notify_list,
2902 MODULE_STATE_GOING, mod);
2903 free_module(mod);
2904 wake_up(&module_wq);
2905 return ret;
2906 }
2907 if (ret > 0) {
2908 printk(KERN_WARNING
2909"%s: '%s'->init suspiciously returned %d, it should follow 0/-E convention\n"
2910"%s: loading module anyway...\n",
2911 __func__, mod->name, ret,
2912 __func__);
2913 dump_stack();
2914 }
2915
2916 /* Now it's a first class citizen! Wake up anyone waiting for it. */
2917 mod->state = MODULE_STATE_LIVE;
2918 wake_up(&module_wq);
2919 blocking_notifier_call_chain(&module_notify_list,
2920 MODULE_STATE_LIVE, mod);
2921
2922 /* We need to finish all async code before the module init sequence is done */
2923 async_synchronize_full();
2924
2925 mutex_lock(&module_mutex);
2926 /* Drop initial reference. */
2927 module_put(mod);
2928 trim_init_extable(mod);
2929#ifdef CONFIG_KALLSYMS
2930 mod->num_symtab = mod->core_num_syms;
2931 mod->symtab = mod->core_symtab;
2932 mod->strtab = mod->core_strtab;
2933#endif
2934 unset_section_ro_nx(mod, mod->module_init);
2935 module_free(mod, mod->module_init);
2936 mod->module_init = NULL;
2937 mod->init_size = 0;
2938 mod->init_text_size = 0;
2939 mutex_unlock(&module_mutex);
2940
2941 return 0;
2942}
2943
2944static inline int within(unsigned long addr, void *start, unsigned long size)
2945{
2946 return ((void *)addr >= start && (void *)addr < start + size);
2947}
2948
2949#ifdef CONFIG_KALLSYMS
2950/*
2951 * This ignores the intensely annoying "mapping symbols" found
2952 * in ARM ELF files: $a, $t and $d.
2953 */
2954static inline int is_arm_mapping_symbol(const char *str)
2955{
2956 return str[0] == '$' && strchr("atd", str[1])
2957 && (str[2] == '\0' || str[2] == '.');
2958}
2959
2960static const char *get_ksymbol(struct module *mod,
2961 unsigned long addr,
2962 unsigned long *size,
2963 unsigned long *offset)
2964{
2965 unsigned int i, best = 0;
2966 unsigned long nextval;
2967
2968 /* At worse, next value is at end of module */
2969 if (within_module_init(addr, mod))
2970 nextval = (unsigned long)mod->module_init+mod->init_text_size;
2971 else
2972 nextval = (unsigned long)mod->module_core+mod->core_text_size;
2973
2974 /* Scan for closest preceeding symbol, and next symbol. (ELF
2975 starts real symbols at 1). */
2976 for (i = 1; i < mod->num_symtab; i++) {
2977 if (mod->symtab[i].st_shndx == SHN_UNDEF)
2978 continue;
2979
2980 /* We ignore unnamed symbols: they're uninformative
2981 * and inserted at a whim. */
2982 if (mod->symtab[i].st_value <= addr
2983 && mod->symtab[i].st_value > mod->symtab[best].st_value
2984 && *(mod->strtab + mod->symtab[i].st_name) != '\0'
2985 && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
2986 best = i;
2987 if (mod->symtab[i].st_value > addr
2988 && mod->symtab[i].st_value < nextval
2989 && *(mod->strtab + mod->symtab[i].st_name) != '\0'
2990 && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
2991 nextval = mod->symtab[i].st_value;
2992 }
2993
2994 if (!best)
2995 return NULL;
2996
2997 if (size)
2998 *size = nextval - mod->symtab[best].st_value;
2999 if (offset)
3000 *offset = addr - mod->symtab[best].st_value;
3001 return mod->strtab + mod->symtab[best].st_name;
3002}
3003
3004/* For kallsyms to ask for address resolution. NULL means not found. Careful
3005 * not to lock to avoid deadlock on oopses, simply disable preemption. */
3006const char *module_address_lookup(unsigned long addr,
3007 unsigned long *size,
3008 unsigned long *offset,
3009 char **modname,
3010 char *namebuf)
3011{
3012 struct module *mod;
3013 const char *ret = NULL;
3014
3015 preempt_disable();
3016 list_for_each_entry_rcu(mod, &modules, list) {
3017 if (within_module_init(addr, mod) ||
3018 within_module_core(addr, mod)) {
3019 if (modname)
3020 *modname = mod->name;
3021 ret = get_ksymbol(mod, addr, size, offset);
3022 break;
3023 }
3024 }
3025 /* Make a copy in here where it's safe */
3026 if (ret) {
3027 strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
3028 ret = namebuf;
3029 }
3030 preempt_enable();
3031 return ret;
3032}
3033
3034int lookup_module_symbol_name(unsigned long addr, char *symname)
3035{
3036 struct module *mod;
3037
3038 preempt_disable();
3039 list_for_each_entry_rcu(mod, &modules, list) {
3040 if (within_module_init(addr, mod) ||
3041 within_module_core(addr, mod)) {
3042 const char *sym;
3043
3044 sym = get_ksymbol(mod, addr, NULL, NULL);
3045 if (!sym)
3046 goto out;
3047 strlcpy(symname, sym, KSYM_NAME_LEN);
3048 preempt_enable();
3049 return 0;
3050 }
3051 }
3052out:
3053 preempt_enable();
3054 return -ERANGE;
3055}
3056
3057int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
3058 unsigned long *offset, char *modname, char *name)
3059{
3060 struct module *mod;
3061
3062 preempt_disable();
3063 list_for_each_entry_rcu(mod, &modules, list) {
3064 if (within_module_init(addr, mod) ||
3065 within_module_core(addr, mod)) {
3066 const char *sym;
3067
3068 sym = get_ksymbol(mod, addr, size, offset);
3069 if (!sym)
3070 goto out;
3071 if (modname)
3072 strlcpy(modname, mod->name, MODULE_NAME_LEN);
3073 if (name)
3074 strlcpy(name, sym, KSYM_NAME_LEN);
3075 preempt_enable();
3076 return 0;
3077 }
3078 }
3079out:
3080 preempt_enable();
3081 return -ERANGE;
3082}
3083
3084int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
3085 char *name, char *module_name, int *exported)
3086{
3087 struct module *mod;
3088
3089 preempt_disable();
3090 list_for_each_entry_rcu(mod, &modules, list) {
3091 if (symnum < mod->num_symtab) {
3092 *value = mod->symtab[symnum].st_value;
3093 *type = mod->symtab[symnum].st_info;
3094 strlcpy(name, mod->strtab + mod->symtab[symnum].st_name,
3095 KSYM_NAME_LEN);
3096 strlcpy(module_name, mod->name, MODULE_NAME_LEN);
3097 *exported = is_exported(name, *value, mod);
3098 preempt_enable();
3099 return 0;
3100 }
3101 symnum -= mod->num_symtab;
3102 }
3103 preempt_enable();
3104 return -ERANGE;
3105}
3106
3107static unsigned long mod_find_symname(struct module *mod, const char *name)
3108{
3109 unsigned int i;
3110
3111 for (i = 0; i < mod->num_symtab; i++)
3112 if (strcmp(name, mod->strtab+mod->symtab[i].st_name) == 0 &&
3113 mod->symtab[i].st_info != 'U')
3114 return mod->symtab[i].st_value;
3115 return 0;
3116}
3117
3118/* Look for this name: can be of form module:name. */
3119unsigned long module_kallsyms_lookup_name(const char *name)
3120{
3121 struct module *mod;
3122 char *colon;
3123 unsigned long ret = 0;
3124
3125 /* Don't lock: we're in enough trouble already. */
3126 preempt_disable();
3127 if ((colon = strchr(name, ':')) != NULL) {
3128 *colon = '\0';
3129 if ((mod = find_module(name)) != NULL)
3130 ret = mod_find_symname(mod, colon+1);
3131 *colon = ':';
3132 } else {
3133 list_for_each_entry_rcu(mod, &modules, list)
3134 if ((ret = mod_find_symname(mod, name)) != 0)
3135 break;
3136 }
3137 preempt_enable();
3138 return ret;
3139}
3140
3141int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
3142 struct module *, unsigned long),
3143 void *data)
3144{
3145 struct module *mod;
3146 unsigned int i;
3147 int ret;
3148
3149 list_for_each_entry(mod, &modules, list) {
3150 for (i = 0; i < mod->num_symtab; i++) {
3151 ret = fn(data, mod->strtab + mod->symtab[i].st_name,
3152 mod, mod->symtab[i].st_value);
3153 if (ret != 0)
3154 return ret;
3155 }
3156 }
3157 return 0;
3158}
3159#endif /* CONFIG_KALLSYMS */
3160
3161static char *module_flags(struct module *mod, char *buf)
3162{
3163 int bx = 0;
3164
3165 if (mod->taints ||
3166 mod->state == MODULE_STATE_GOING ||
3167 mod->state == MODULE_STATE_COMING) {
3168 buf[bx++] = '(';
3169 if (mod->taints & (1 << TAINT_PROPRIETARY_MODULE))
3170 buf[bx++] = 'P';
3171 if (mod->taints & (1 << TAINT_FORCED_MODULE))
3172 buf[bx++] = 'F';
3173 if (mod->taints & (1 << TAINT_CRAP))
3174 buf[bx++] = 'C';
3175 /*
3176 * TAINT_FORCED_RMMOD: could be added.
3177 * TAINT_UNSAFE_SMP, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't
3178 * apply to modules.
3179 */
3180
3181 /* Show a - for module-is-being-unloaded */
3182 if (mod->state == MODULE_STATE_GOING)
3183 buf[bx++] = '-';
3184 /* Show a + for module-is-being-loaded */
3185 if (mod->state == MODULE_STATE_COMING)
3186 buf[bx++] = '+';
3187 buf[bx++] = ')';
3188 }
3189 buf[bx] = '\0';
3190
3191 return buf;
3192}
3193
3194#ifdef CONFIG_PROC_FS
3195/* Called by the /proc file system to return a list of modules. */
3196static void *m_start(struct seq_file *m, loff_t *pos)
3197{
3198 mutex_lock(&module_mutex);
3199 return seq_list_start(&modules, *pos);
3200}
3201
3202static void *m_next(struct seq_file *m, void *p, loff_t *pos)
3203{
3204 return seq_list_next(p, &modules, pos);
3205}
3206
3207static void m_stop(struct seq_file *m, void *p)
3208{
3209 mutex_unlock(&module_mutex);
3210}
3211
3212static int m_show(struct seq_file *m, void *p)
3213{
3214 struct module *mod = list_entry(p, struct module, list);
3215 char buf[8];
3216
3217 seq_printf(m, "%s %u",
3218 mod->name, mod->init_size + mod->core_size);
3219 print_unload_info(m, mod);
3220
3221 /* Informative for users. */
3222 seq_printf(m, " %s",
3223 mod->state == MODULE_STATE_GOING ? "Unloading":
3224 mod->state == MODULE_STATE_COMING ? "Loading":
3225 "Live");
3226 /* Used by oprofile and other similar tools. */
3227 seq_printf(m, " 0x%p", mod->module_core);
3228
3229 /* Taints info */
3230 if (mod->taints)
3231 seq_printf(m, " %s", module_flags(mod, buf));
3232
3233 seq_printf(m, "\n");
3234 return 0;
3235}
3236
3237/* Format: modulename size refcount deps address
3238
3239 Where refcount is a number or -, and deps is a comma-separated list
3240 of depends or -.
3241*/
3242static const struct seq_operations modules_op = {
3243 .start = m_start,
3244 .next = m_next,
3245 .stop = m_stop,
3246 .show = m_show
3247};
3248
3249static int modules_open(struct inode *inode, struct file *file)
3250{
3251 return seq_open(file, &modules_op);
3252}
3253
3254static const struct file_operations proc_modules_operations = {
3255 .open = modules_open,
3256 .read = seq_read,
3257 .llseek = seq_lseek,
3258 .release = seq_release,
3259};
3260
3261static int __init proc_modules_init(void)
3262{
3263 proc_create("modules", 0, NULL, &proc_modules_operations);
3264 return 0;
3265}
3266module_init(proc_modules_init);
3267#endif
3268
3269/* Given an address, look for it in the module exception tables. */
3270const struct exception_table_entry *search_module_extables(unsigned long addr)
3271{
3272 const struct exception_table_entry *e = NULL;
3273 struct module *mod;
3274
3275 preempt_disable();
3276 list_for_each_entry_rcu(mod, &modules, list) {
3277 if (mod->num_exentries == 0)
3278 continue;
3279
3280 e = search_extable(mod->extable,
3281 mod->extable + mod->num_exentries - 1,
3282 addr);
3283 if (e)
3284 break;
3285 }
3286 preempt_enable();
3287
3288 /* Now, if we found one, we are running inside it now, hence
3289 we cannot unload the module, hence no refcnt needed. */
3290 return e;
3291}
3292
3293/*
3294 * is_module_address - is this address inside a module?
3295 * @addr: the address to check.
3296 *
3297 * See is_module_text_address() if you simply want to see if the address
3298 * is code (not data).
3299 */
3300bool is_module_address(unsigned long addr)
3301{
3302 bool ret;
3303
3304 preempt_disable();
3305 ret = __module_address(addr) != NULL;
3306 preempt_enable();
3307
3308 return ret;
3309}
3310
3311/*
3312 * __module_address - get the module which contains an address.
3313 * @addr: the address.
3314 *
3315 * Must be called with preempt disabled or module mutex held so that
3316 * module doesn't get freed during this.
3317 */
3318struct module *__module_address(unsigned long addr)
3319{
3320 struct module *mod;
3321
3322 if (addr < module_addr_min || addr > module_addr_max)
3323 return NULL;
3324
3325 list_for_each_entry_rcu(mod, &modules, list)
3326 if (within_module_core(addr, mod)
3327 || within_module_init(addr, mod))
3328 return mod;
3329 return NULL;
3330}
3331EXPORT_SYMBOL_GPL(__module_address);
3332
3333/*
3334 * is_module_text_address - is this address inside module code?
3335 * @addr: the address to check.
3336 *
3337 * See is_module_address() if you simply want to see if the address is
3338 * anywhere in a module. See kernel_text_address() for testing if an
3339 * address corresponds to kernel or module code.
3340 */
3341bool is_module_text_address(unsigned long addr)
3342{
3343 bool ret;
3344
3345 preempt_disable();
3346 ret = __module_text_address(addr) != NULL;
3347 preempt_enable();
3348
3349 return ret;
3350}
3351
3352/*
3353 * __module_text_address - get the module whose code contains an address.
3354 * @addr: the address.
3355 *
3356 * Must be called with preempt disabled or module mutex held so that
3357 * module doesn't get freed during this.
3358 */
3359struct module *__module_text_address(unsigned long addr)
3360{
3361 struct module *mod = __module_address(addr);
3362 if (mod) {
3363 /* Make sure it's within the text section. */
3364 if (!within(addr, mod->module_init, mod->init_text_size)
3365 && !within(addr, mod->module_core, mod->core_text_size))
3366 mod = NULL;
3367 }
3368 return mod;
3369}
3370EXPORT_SYMBOL_GPL(__module_text_address);
3371
3372/* Don't grab lock, we're oopsing. */
3373void print_modules(void)
3374{
3375 struct module *mod;
3376 char buf[8];
3377
3378 printk(KERN_DEFAULT "Modules linked in:");
3379 /* Most callers should already have preempt disabled, but make sure */
3380 preempt_disable();
3381 list_for_each_entry_rcu(mod, &modules, list)
3382 printk(" %s%s", mod->name, module_flags(mod, buf));
3383 preempt_enable();
3384 if (last_unloaded_module[0])
3385 printk(" [last unloaded: %s]", last_unloaded_module);
3386 printk("\n");
3387}
3388
3389#ifdef CONFIG_MODVERSIONS
3390/* Generate the signature for all relevant module structures here.
3391 * If these change, we don't want to try to parse the module. */
3392void module_layout(struct module *mod,
3393 struct modversion_info *ver,
3394 struct kernel_param *kp,
3395 struct kernel_symbol *ks,
3396 struct tracepoint *tp)
3397{
3398}
3399EXPORT_SYMBOL(module_layout);
3400#endif
3401
3402#ifdef CONFIG_TRACEPOINTS
3403void module_update_tracepoints(void)
3404{
3405 struct module *mod;
3406
3407 mutex_lock(&module_mutex);
3408 list_for_each_entry(mod, &modules, list)
3409 if (!mod->taints)
3410 tracepoint_update_probe_range(mod->tracepoints,
3411 mod->tracepoints + mod->num_tracepoints);
3412 mutex_unlock(&module_mutex);
3413}
3414
3415/*
3416 * Returns 0 if current not found.
3417 * Returns 1 if current found.
3418 */
3419int module_get_iter_tracepoints(struct tracepoint_iter *iter)
3420{
3421 struct module *iter_mod;
3422 int found = 0;
3423
3424 mutex_lock(&module_mutex);
3425 list_for_each_entry(iter_mod, &modules, list) {
3426 if (!iter_mod->taints) {
3427 /*
3428 * Sorted module list
3429 */
3430 if (iter_mod < iter->module)
3431 continue;
3432 else if (iter_mod > iter->module)
3433 iter->tracepoint = NULL;
3434 found = tracepoint_get_iter_range(&iter->tracepoint,
3435 iter_mod->tracepoints,
3436 iter_mod->tracepoints
3437 + iter_mod->num_tracepoints);
3438 if (found) {
3439 iter->module = iter_mod;
3440 break;
3441 }
3442 }
3443 }
3444 mutex_unlock(&module_mutex);
3445 return found;
3446}
3447#endif