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1 /*
2 Copyright (C) 2002 Richard Henderson
3 Copyright (C) 2001 Rusty Russell, 2002 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/init.h>
22 #include <linux/kernel.h>
23 #include <linux/slab.h>
24 #include <linux/vmalloc.h>
25 #include <linux/elf.h>
26 #include <linux/seq_file.h>
27 #include <linux/syscalls.h>
28 #include <linux/fcntl.h>
29 #include <linux/rcupdate.h>
30 #include <linux/capability.h>
31 #include <linux/cpu.h>
32 #include <linux/moduleparam.h>
33 #include <linux/errno.h>
34 #include <linux/err.h>
35 #include <linux/vermagic.h>
36 #include <linux/notifier.h>
37 #include <linux/sched.h>
38 #include <linux/stop_machine.h>
39 #include <linux/device.h>
40 #include <linux/string.h>
41 #include <linux/mutex.h>
42 #include <linux/unwind.h>
43 #include <asm/uaccess.h>
44 #include <asm/semaphore.h>
45 #include <asm/cacheflush.h>
46 #include <linux/license.h>
47
48 #if 0
49 #define DEBUGP printk
50 #else
51 #define DEBUGP(fmt , a...)
52 #endif
53
54 #ifndef ARCH_SHF_SMALL
55 #define ARCH_SHF_SMALL 0
56 #endif
57
58 /* If this is set, the section belongs in the init part of the module */
59 #define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
60
61 /* Protects module list */
62 static DEFINE_SPINLOCK(modlist_lock);
63
64 /* List of modules, protected by module_mutex AND modlist_lock */
65 static DEFINE_MUTEX(module_mutex);
66 static LIST_HEAD(modules);
67
68 static BLOCKING_NOTIFIER_HEAD(module_notify_list);
69
70 int register_module_notifier(struct notifier_block * nb)
71 {
72 return blocking_notifier_chain_register(&module_notify_list, nb);
73 }
74 EXPORT_SYMBOL(register_module_notifier);
75
76 int unregister_module_notifier(struct notifier_block * nb)
77 {
78 return blocking_notifier_chain_unregister(&module_notify_list, nb);
79 }
80 EXPORT_SYMBOL(unregister_module_notifier);
81
82 /* We require a truly strong try_module_get() */
83 static inline int strong_try_module_get(struct module *mod)
84 {
85 if (mod && mod->state == MODULE_STATE_COMING)
86 return 0;
87 return try_module_get(mod);
88 }
89
90 static inline void add_taint_module(struct module *mod, unsigned flag)
91 {
92 add_taint(flag);
93 mod->taints |= flag;
94 }
95
96 /* A thread that wants to hold a reference to a module only while it
97 * is running can call ths to safely exit.
98 * nfsd and lockd use this.
99 */
100 void __module_put_and_exit(struct module *mod, long code)
101 {
102 module_put(mod);
103 do_exit(code);
104 }
105 EXPORT_SYMBOL(__module_put_and_exit);
106
107 /* Find a module section: 0 means not found. */
108 static unsigned int find_sec(Elf_Ehdr *hdr,
109 Elf_Shdr *sechdrs,
110 const char *secstrings,
111 const char *name)
112 {
113 unsigned int i;
114
115 for (i = 1; i < hdr->e_shnum; i++)
116 /* Alloc bit cleared means "ignore it." */
117 if ((sechdrs[i].sh_flags & SHF_ALLOC)
118 && strcmp(secstrings+sechdrs[i].sh_name, name) == 0)
119 return i;
120 return 0;
121 }
122
123 /* Provided by the linker */
124 extern const struct kernel_symbol __start___ksymtab[];
125 extern const struct kernel_symbol __stop___ksymtab[];
126 extern const struct kernel_symbol __start___ksymtab_gpl[];
127 extern const struct kernel_symbol __stop___ksymtab_gpl[];
128 extern const struct kernel_symbol __start___ksymtab_gpl_future[];
129 extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
130 extern const struct kernel_symbol __start___ksymtab_unused[];
131 extern const struct kernel_symbol __stop___ksymtab_unused[];
132 extern const struct kernel_symbol __start___ksymtab_unused_gpl[];
133 extern const struct kernel_symbol __stop___ksymtab_unused_gpl[];
134 extern const struct kernel_symbol __start___ksymtab_gpl_future[];
135 extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
136 extern const unsigned long __start___kcrctab[];
137 extern const unsigned long __start___kcrctab_gpl[];
138 extern const unsigned long __start___kcrctab_gpl_future[];
139 extern const unsigned long __start___kcrctab_unused[];
140 extern const unsigned long __start___kcrctab_unused_gpl[];
141
142 #ifndef CONFIG_MODVERSIONS
143 #define symversion(base, idx) NULL
144 #else
145 #define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
146 #endif
147
148 /* lookup symbol in given range of kernel_symbols */
149 static const struct kernel_symbol *lookup_symbol(const char *name,
150 const struct kernel_symbol *start,
151 const struct kernel_symbol *stop)
152 {
153 const struct kernel_symbol *ks = start;
154 for (; ks < stop; ks++)
155 if (strcmp(ks->name, name) == 0)
156 return ks;
157 return NULL;
158 }
159
160 static void printk_unused_warning(const char *name)
161 {
162 printk(KERN_WARNING "Symbol %s is marked as UNUSED, "
163 "however this module is using it.\n", name);
164 printk(KERN_WARNING "This symbol will go away in the future.\n");
165 printk(KERN_WARNING "Please evalute if this is the right api to use, "
166 "and if it really is, submit a report the linux kernel "
167 "mailinglist together with submitting your code for "
168 "inclusion.\n");
169 }
170
171 /* Find a symbol, return value, crc and module which owns it */
172 static unsigned long __find_symbol(const char *name,
173 struct module **owner,
174 const unsigned long **crc,
175 int gplok)
176 {
177 struct module *mod;
178 const struct kernel_symbol *ks;
179
180 /* Core kernel first. */
181 *owner = NULL;
182 ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
183 if (ks) {
184 *crc = symversion(__start___kcrctab, (ks - __start___ksymtab));
185 return ks->value;
186 }
187 if (gplok) {
188 ks = lookup_symbol(name, __start___ksymtab_gpl,
189 __stop___ksymtab_gpl);
190 if (ks) {
191 *crc = symversion(__start___kcrctab_gpl,
192 (ks - __start___ksymtab_gpl));
193 return ks->value;
194 }
195 }
196 ks = lookup_symbol(name, __start___ksymtab_gpl_future,
197 __stop___ksymtab_gpl_future);
198 if (ks) {
199 if (!gplok) {
200 printk(KERN_WARNING "Symbol %s is being used "
201 "by a non-GPL module, which will not "
202 "be allowed in the future\n", name);
203 printk(KERN_WARNING "Please see the file "
204 "Documentation/feature-removal-schedule.txt "
205 "in the kernel source tree for more "
206 "details.\n");
207 }
208 *crc = symversion(__start___kcrctab_gpl_future,
209 (ks - __start___ksymtab_gpl_future));
210 return ks->value;
211 }
212
213 ks = lookup_symbol(name, __start___ksymtab_unused,
214 __stop___ksymtab_unused);
215 if (ks) {
216 printk_unused_warning(name);
217 *crc = symversion(__start___kcrctab_unused,
218 (ks - __start___ksymtab_unused));
219 return ks->value;
220 }
221
222 if (gplok)
223 ks = lookup_symbol(name, __start___ksymtab_unused_gpl,
224 __stop___ksymtab_unused_gpl);
225 if (ks) {
226 printk_unused_warning(name);
227 *crc = symversion(__start___kcrctab_unused_gpl,
228 (ks - __start___ksymtab_unused_gpl));
229 return ks->value;
230 }
231
232 /* Now try modules. */
233 list_for_each_entry(mod, &modules, list) {
234 *owner = mod;
235 ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
236 if (ks) {
237 *crc = symversion(mod->crcs, (ks - mod->syms));
238 return ks->value;
239 }
240
241 if (gplok) {
242 ks = lookup_symbol(name, mod->gpl_syms,
243 mod->gpl_syms + mod->num_gpl_syms);
244 if (ks) {
245 *crc = symversion(mod->gpl_crcs,
246 (ks - mod->gpl_syms));
247 return ks->value;
248 }
249 }
250 ks = lookup_symbol(name, mod->unused_syms, mod->unused_syms + mod->num_unused_syms);
251 if (ks) {
252 printk_unused_warning(name);
253 *crc = symversion(mod->unused_crcs, (ks - mod->unused_syms));
254 return ks->value;
255 }
256
257 if (gplok) {
258 ks = lookup_symbol(name, mod->unused_gpl_syms,
259 mod->unused_gpl_syms + mod->num_unused_gpl_syms);
260 if (ks) {
261 printk_unused_warning(name);
262 *crc = symversion(mod->unused_gpl_crcs,
263 (ks - mod->unused_gpl_syms));
264 return ks->value;
265 }
266 }
267 ks = lookup_symbol(name, mod->gpl_future_syms,
268 (mod->gpl_future_syms +
269 mod->num_gpl_future_syms));
270 if (ks) {
271 if (!gplok) {
272 printk(KERN_WARNING "Symbol %s is being used "
273 "by a non-GPL module, which will not "
274 "be allowed in the future\n", name);
275 printk(KERN_WARNING "Please see the file "
276 "Documentation/feature-removal-schedule.txt "
277 "in the kernel source tree for more "
278 "details.\n");
279 }
280 *crc = symversion(mod->gpl_future_crcs,
281 (ks - mod->gpl_future_syms));
282 return ks->value;
283 }
284 }
285 DEBUGP("Failed to find symbol %s\n", name);
286 return 0;
287 }
288
289 /* Search for module by name: must hold module_mutex. */
290 static struct module *find_module(const char *name)
291 {
292 struct module *mod;
293
294 list_for_each_entry(mod, &modules, list) {
295 if (strcmp(mod->name, name) == 0)
296 return mod;
297 }
298 return NULL;
299 }
300
301 #ifdef CONFIG_SMP
302 /* Number of blocks used and allocated. */
303 static unsigned int pcpu_num_used, pcpu_num_allocated;
304 /* Size of each block. -ve means used. */
305 static int *pcpu_size;
306
307 static int split_block(unsigned int i, unsigned short size)
308 {
309 /* Reallocation required? */
310 if (pcpu_num_used + 1 > pcpu_num_allocated) {
311 int *new = kmalloc(sizeof(new[0]) * pcpu_num_allocated*2,
312 GFP_KERNEL);
313 if (!new)
314 return 0;
315
316 memcpy(new, pcpu_size, sizeof(new[0])*pcpu_num_allocated);
317 pcpu_num_allocated *= 2;
318 kfree(pcpu_size);
319 pcpu_size = new;
320 }
321
322 /* Insert a new subblock */
323 memmove(&pcpu_size[i+1], &pcpu_size[i],
324 sizeof(pcpu_size[0]) * (pcpu_num_used - i));
325 pcpu_num_used++;
326
327 pcpu_size[i+1] -= size;
328 pcpu_size[i] = size;
329 return 1;
330 }
331
332 static inline unsigned int block_size(int val)
333 {
334 if (val < 0)
335 return -val;
336 return val;
337 }
338
339 /* Created by linker magic */
340 extern char __per_cpu_start[], __per_cpu_end[];
341
342 static void *percpu_modalloc(unsigned long size, unsigned long align,
343 const char *name)
344 {
345 unsigned long extra;
346 unsigned int i;
347 void *ptr;
348
349 if (align > SMP_CACHE_BYTES) {
350 printk(KERN_WARNING "%s: per-cpu alignment %li > %i\n",
351 name, align, SMP_CACHE_BYTES);
352 align = SMP_CACHE_BYTES;
353 }
354
355 ptr = __per_cpu_start;
356 for (i = 0; i < pcpu_num_used; ptr += block_size(pcpu_size[i]), i++) {
357 /* Extra for alignment requirement. */
358 extra = ALIGN((unsigned long)ptr, align) - (unsigned long)ptr;
359 BUG_ON(i == 0 && extra != 0);
360
361 if (pcpu_size[i] < 0 || pcpu_size[i] < extra + size)
362 continue;
363
364 /* Transfer extra to previous block. */
365 if (pcpu_size[i-1] < 0)
366 pcpu_size[i-1] -= extra;
367 else
368 pcpu_size[i-1] += extra;
369 pcpu_size[i] -= extra;
370 ptr += extra;
371
372 /* Split block if warranted */
373 if (pcpu_size[i] - size > sizeof(unsigned long))
374 if (!split_block(i, size))
375 return NULL;
376
377 /* Mark allocated */
378 pcpu_size[i] = -pcpu_size[i];
379 return ptr;
380 }
381
382 printk(KERN_WARNING "Could not allocate %lu bytes percpu data\n",
383 size);
384 return NULL;
385 }
386
387 static void percpu_modfree(void *freeme)
388 {
389 unsigned int i;
390 void *ptr = __per_cpu_start + block_size(pcpu_size[0]);
391
392 /* First entry is core kernel percpu data. */
393 for (i = 1; i < pcpu_num_used; ptr += block_size(pcpu_size[i]), i++) {
394 if (ptr == freeme) {
395 pcpu_size[i] = -pcpu_size[i];
396 goto free;
397 }
398 }
399 BUG();
400
401 free:
402 /* Merge with previous? */
403 if (pcpu_size[i-1] >= 0) {
404 pcpu_size[i-1] += pcpu_size[i];
405 pcpu_num_used--;
406 memmove(&pcpu_size[i], &pcpu_size[i+1],
407 (pcpu_num_used - i) * sizeof(pcpu_size[0]));
408 i--;
409 }
410 /* Merge with next? */
411 if (i+1 < pcpu_num_used && pcpu_size[i+1] >= 0) {
412 pcpu_size[i] += pcpu_size[i+1];
413 pcpu_num_used--;
414 memmove(&pcpu_size[i+1], &pcpu_size[i+2],
415 (pcpu_num_used - (i+1)) * sizeof(pcpu_size[0]));
416 }
417 }
418
419 static unsigned int find_pcpusec(Elf_Ehdr *hdr,
420 Elf_Shdr *sechdrs,
421 const char *secstrings)
422 {
423 return find_sec(hdr, sechdrs, secstrings, ".data.percpu");
424 }
425
426 static int percpu_modinit(void)
427 {
428 pcpu_num_used = 2;
429 pcpu_num_allocated = 2;
430 pcpu_size = kmalloc(sizeof(pcpu_size[0]) * pcpu_num_allocated,
431 GFP_KERNEL);
432 /* Static in-kernel percpu data (used). */
433 pcpu_size[0] = -ALIGN(__per_cpu_end-__per_cpu_start, SMP_CACHE_BYTES);
434 /* Free room. */
435 pcpu_size[1] = PERCPU_ENOUGH_ROOM + pcpu_size[0];
436 if (pcpu_size[1] < 0) {
437 printk(KERN_ERR "No per-cpu room for modules.\n");
438 pcpu_num_used = 1;
439 }
440
441 return 0;
442 }
443 __initcall(percpu_modinit);
444 #else /* ... !CONFIG_SMP */
445 static inline void *percpu_modalloc(unsigned long size, unsigned long align,
446 const char *name)
447 {
448 return NULL;
449 }
450 static inline void percpu_modfree(void *pcpuptr)
451 {
452 BUG();
453 }
454 static inline unsigned int find_pcpusec(Elf_Ehdr *hdr,
455 Elf_Shdr *sechdrs,
456 const char *secstrings)
457 {
458 return 0;
459 }
460 static inline void percpu_modcopy(void *pcpudst, const void *src,
461 unsigned long size)
462 {
463 /* pcpusec should be 0, and size of that section should be 0. */
464 BUG_ON(size != 0);
465 }
466 #endif /* CONFIG_SMP */
467
468 #define MODINFO_ATTR(field) \
469 static void setup_modinfo_##field(struct module *mod, const char *s) \
470 { \
471 mod->field = kstrdup(s, GFP_KERNEL); \
472 } \
473 static ssize_t show_modinfo_##field(struct module_attribute *mattr, \
474 struct module *mod, char *buffer) \
475 { \
476 return sprintf(buffer, "%s\n", mod->field); \
477 } \
478 static int modinfo_##field##_exists(struct module *mod) \
479 { \
480 return mod->field != NULL; \
481 } \
482 static void free_modinfo_##field(struct module *mod) \
483 { \
484 kfree(mod->field); \
485 mod->field = NULL; \
486 } \
487 static struct module_attribute modinfo_##field = { \
488 .attr = { .name = __stringify(field), .mode = 0444, \
489 .owner = THIS_MODULE }, \
490 .show = show_modinfo_##field, \
491 .setup = setup_modinfo_##field, \
492 .test = modinfo_##field##_exists, \
493 .free = free_modinfo_##field, \
494 };
495
496 MODINFO_ATTR(version);
497 MODINFO_ATTR(srcversion);
498
499 #ifdef CONFIG_MODULE_UNLOAD
500 /* Init the unload section of the module. */
501 static void module_unload_init(struct module *mod)
502 {
503 unsigned int i;
504
505 INIT_LIST_HEAD(&mod->modules_which_use_me);
506 for (i = 0; i < NR_CPUS; i++)
507 local_set(&mod->ref[i].count, 0);
508 /* Hold reference count during initialization. */
509 local_set(&mod->ref[raw_smp_processor_id()].count, 1);
510 /* Backwards compatibility macros put refcount during init. */
511 mod->waiter = current;
512 }
513
514 /* modules using other modules */
515 struct module_use
516 {
517 struct list_head list;
518 struct module *module_which_uses;
519 };
520
521 /* Does a already use b? */
522 static int already_uses(struct module *a, struct module *b)
523 {
524 struct module_use *use;
525
526 list_for_each_entry(use, &b->modules_which_use_me, list) {
527 if (use->module_which_uses == a) {
528 DEBUGP("%s uses %s!\n", a->name, b->name);
529 return 1;
530 }
531 }
532 DEBUGP("%s does not use %s!\n", a->name, b->name);
533 return 0;
534 }
535
536 /* Module a uses b */
537 static int use_module(struct module *a, struct module *b)
538 {
539 struct module_use *use;
540 int no_warn;
541
542 if (b == NULL || already_uses(a, b)) return 1;
543
544 if (!strong_try_module_get(b))
545 return 0;
546
547 DEBUGP("Allocating new usage for %s.\n", a->name);
548 use = kmalloc(sizeof(*use), GFP_ATOMIC);
549 if (!use) {
550 printk("%s: out of memory loading\n", a->name);
551 module_put(b);
552 return 0;
553 }
554
555 use->module_which_uses = a;
556 list_add(&use->list, &b->modules_which_use_me);
557 no_warn = sysfs_create_link(b->holders_dir, &a->mkobj.kobj, a->name);
558 return 1;
559 }
560
561 /* Clear the unload stuff of the module. */
562 static void module_unload_free(struct module *mod)
563 {
564 struct module *i;
565
566 list_for_each_entry(i, &modules, list) {
567 struct module_use *use;
568
569 list_for_each_entry(use, &i->modules_which_use_me, list) {
570 if (use->module_which_uses == mod) {
571 DEBUGP("%s unusing %s\n", mod->name, i->name);
572 module_put(i);
573 list_del(&use->list);
574 kfree(use);
575 sysfs_remove_link(i->holders_dir, mod->name);
576 /* There can be at most one match. */
577 break;
578 }
579 }
580 }
581 }
582
583 #ifdef CONFIG_MODULE_FORCE_UNLOAD
584 static inline int try_force_unload(unsigned int flags)
585 {
586 int ret = (flags & O_TRUNC);
587 if (ret)
588 add_taint(TAINT_FORCED_RMMOD);
589 return ret;
590 }
591 #else
592 static inline int try_force_unload(unsigned int flags)
593 {
594 return 0;
595 }
596 #endif /* CONFIG_MODULE_FORCE_UNLOAD */
597
598 struct stopref
599 {
600 struct module *mod;
601 int flags;
602 int *forced;
603 };
604
605 /* Whole machine is stopped with interrupts off when this runs. */
606 static int __try_stop_module(void *_sref)
607 {
608 struct stopref *sref = _sref;
609
610 /* If it's not unused, quit unless we are told to block. */
611 if ((sref->flags & O_NONBLOCK) && module_refcount(sref->mod) != 0) {
612 if (!(*sref->forced = try_force_unload(sref->flags)))
613 return -EWOULDBLOCK;
614 }
615
616 /* Mark it as dying. */
617 sref->mod->state = MODULE_STATE_GOING;
618 return 0;
619 }
620
621 static int try_stop_module(struct module *mod, int flags, int *forced)
622 {
623 struct stopref sref = { mod, flags, forced };
624
625 return stop_machine_run(__try_stop_module, &sref, NR_CPUS);
626 }
627
628 unsigned int module_refcount(struct module *mod)
629 {
630 unsigned int i, total = 0;
631
632 for (i = 0; i < NR_CPUS; i++)
633 total += local_read(&mod->ref[i].count);
634 return total;
635 }
636 EXPORT_SYMBOL(module_refcount);
637
638 /* This exists whether we can unload or not */
639 static void free_module(struct module *mod);
640
641 static void wait_for_zero_refcount(struct module *mod)
642 {
643 /* Since we might sleep for some time, drop the semaphore first */
644 mutex_unlock(&module_mutex);
645 for (;;) {
646 DEBUGP("Looking at refcount...\n");
647 set_current_state(TASK_UNINTERRUPTIBLE);
648 if (module_refcount(mod) == 0)
649 break;
650 schedule();
651 }
652 current->state = TASK_RUNNING;
653 mutex_lock(&module_mutex);
654 }
655
656 asmlinkage long
657 sys_delete_module(const char __user *name_user, unsigned int flags)
658 {
659 struct module *mod;
660 char name[MODULE_NAME_LEN];
661 int ret, forced = 0;
662
663 if (!capable(CAP_SYS_MODULE))
664 return -EPERM;
665
666 if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
667 return -EFAULT;
668 name[MODULE_NAME_LEN-1] = '\0';
669
670 if (mutex_lock_interruptible(&module_mutex) != 0)
671 return -EINTR;
672
673 mod = find_module(name);
674 if (!mod) {
675 ret = -ENOENT;
676 goto out;
677 }
678
679 if (!list_empty(&mod->modules_which_use_me)) {
680 /* Other modules depend on us: get rid of them first. */
681 ret = -EWOULDBLOCK;
682 goto out;
683 }
684
685 /* Doing init or already dying? */
686 if (mod->state != MODULE_STATE_LIVE) {
687 /* FIXME: if (force), slam module count and wake up
688 waiter --RR */
689 DEBUGP("%s already dying\n", mod->name);
690 ret = -EBUSY;
691 goto out;
692 }
693
694 /* If it has an init func, it must have an exit func to unload */
695 if ((mod->init != NULL && mod->exit == NULL)
696 || mod->unsafe) {
697 forced = try_force_unload(flags);
698 if (!forced) {
699 /* This module can't be removed */
700 ret = -EBUSY;
701 goto out;
702 }
703 }
704
705 /* Set this up before setting mod->state */
706 mod->waiter = current;
707
708 /* Stop the machine so refcounts can't move and disable module. */
709 ret = try_stop_module(mod, flags, &forced);
710 if (ret != 0)
711 goto out;
712
713 /* Never wait if forced. */
714 if (!forced && module_refcount(mod) != 0)
715 wait_for_zero_refcount(mod);
716
717 /* Final destruction now noone is using it. */
718 if (mod->exit != NULL) {
719 mutex_unlock(&module_mutex);
720 mod->exit();
721 mutex_lock(&module_mutex);
722 }
723 free_module(mod);
724
725 out:
726 mutex_unlock(&module_mutex);
727 return ret;
728 }
729
730 static void print_unload_info(struct seq_file *m, struct module *mod)
731 {
732 struct module_use *use;
733 int printed_something = 0;
734
735 seq_printf(m, " %u ", module_refcount(mod));
736
737 /* Always include a trailing , so userspace can differentiate
738 between this and the old multi-field proc format. */
739 list_for_each_entry(use, &mod->modules_which_use_me, list) {
740 printed_something = 1;
741 seq_printf(m, "%s,", use->module_which_uses->name);
742 }
743
744 if (mod->unsafe) {
745 printed_something = 1;
746 seq_printf(m, "[unsafe],");
747 }
748
749 if (mod->init != NULL && mod->exit == NULL) {
750 printed_something = 1;
751 seq_printf(m, "[permanent],");
752 }
753
754 if (!printed_something)
755 seq_printf(m, "-");
756 }
757
758 void __symbol_put(const char *symbol)
759 {
760 struct module *owner;
761 unsigned long flags;
762 const unsigned long *crc;
763
764 spin_lock_irqsave(&modlist_lock, flags);
765 if (!__find_symbol(symbol, &owner, &crc, 1))
766 BUG();
767 module_put(owner);
768 spin_unlock_irqrestore(&modlist_lock, flags);
769 }
770 EXPORT_SYMBOL(__symbol_put);
771
772 void symbol_put_addr(void *addr)
773 {
774 struct module *modaddr;
775
776 if (core_kernel_text((unsigned long)addr))
777 return;
778
779 if (!(modaddr = module_text_address((unsigned long)addr)))
780 BUG();
781 module_put(modaddr);
782 }
783 EXPORT_SYMBOL_GPL(symbol_put_addr);
784
785 static ssize_t show_refcnt(struct module_attribute *mattr,
786 struct module *mod, char *buffer)
787 {
788 /* sysfs holds a reference */
789 return sprintf(buffer, "%u\n", module_refcount(mod)-1);
790 }
791
792 static struct module_attribute refcnt = {
793 .attr = { .name = "refcnt", .mode = 0444, .owner = THIS_MODULE },
794 .show = show_refcnt,
795 };
796
797 void module_put(struct module *module)
798 {
799 if (module) {
800 unsigned int cpu = get_cpu();
801 local_dec(&module->ref[cpu].count);
802 /* Maybe they're waiting for us to drop reference? */
803 if (unlikely(!module_is_live(module)))
804 wake_up_process(module->waiter);
805 put_cpu();
806 }
807 }
808 EXPORT_SYMBOL(module_put);
809
810 #else /* !CONFIG_MODULE_UNLOAD */
811 static void print_unload_info(struct seq_file *m, struct module *mod)
812 {
813 /* We don't know the usage count, or what modules are using. */
814 seq_printf(m, " - -");
815 }
816
817 static inline void module_unload_free(struct module *mod)
818 {
819 }
820
821 static inline int use_module(struct module *a, struct module *b)
822 {
823 return strong_try_module_get(b);
824 }
825
826 static inline void module_unload_init(struct module *mod)
827 {
828 }
829 #endif /* CONFIG_MODULE_UNLOAD */
830
831 static ssize_t show_initstate(struct module_attribute *mattr,
832 struct module *mod, char *buffer)
833 {
834 const char *state = "unknown";
835
836 switch (mod->state) {
837 case MODULE_STATE_LIVE:
838 state = "live";
839 break;
840 case MODULE_STATE_COMING:
841 state = "coming";
842 break;
843 case MODULE_STATE_GOING:
844 state = "going";
845 break;
846 }
847 return sprintf(buffer, "%s\n", state);
848 }
849
850 static struct module_attribute initstate = {
851 .attr = { .name = "initstate", .mode = 0444, .owner = THIS_MODULE },
852 .show = show_initstate,
853 };
854
855 static struct module_attribute *modinfo_attrs[] = {
856 &modinfo_version,
857 &modinfo_srcversion,
858 &initstate,
859 #ifdef CONFIG_MODULE_UNLOAD
860 &refcnt,
861 #endif
862 NULL,
863 };
864
865 static const char vermagic[] = VERMAGIC_STRING;
866
867 #ifdef CONFIG_MODVERSIONS
868 static int check_version(Elf_Shdr *sechdrs,
869 unsigned int versindex,
870 const char *symname,
871 struct module *mod,
872 const unsigned long *crc)
873 {
874 unsigned int i, num_versions;
875 struct modversion_info *versions;
876
877 /* Exporting module didn't supply crcs? OK, we're already tainted. */
878 if (!crc)
879 return 1;
880
881 versions = (void *) sechdrs[versindex].sh_addr;
882 num_versions = sechdrs[versindex].sh_size
883 / sizeof(struct modversion_info);
884
885 for (i = 0; i < num_versions; i++) {
886 if (strcmp(versions[i].name, symname) != 0)
887 continue;
888
889 if (versions[i].crc == *crc)
890 return 1;
891 printk("%s: disagrees about version of symbol %s\n",
892 mod->name, symname);
893 DEBUGP("Found checksum %lX vs module %lX\n",
894 *crc, versions[i].crc);
895 return 0;
896 }
897 /* Not in module's version table. OK, but that taints the kernel. */
898 if (!(tainted & TAINT_FORCED_MODULE))
899 printk("%s: no version for \"%s\" found: kernel tainted.\n",
900 mod->name, symname);
901 add_taint_module(mod, TAINT_FORCED_MODULE);
902 return 1;
903 }
904
905 static inline int check_modstruct_version(Elf_Shdr *sechdrs,
906 unsigned int versindex,
907 struct module *mod)
908 {
909 const unsigned long *crc;
910 struct module *owner;
911
912 if (!__find_symbol("struct_module", &owner, &crc, 1))
913 BUG();
914 return check_version(sechdrs, versindex, "struct_module", mod,
915 crc);
916 }
917
918 /* First part is kernel version, which we ignore. */
919 static inline int same_magic(const char *amagic, const char *bmagic)
920 {
921 amagic += strcspn(amagic, " ");
922 bmagic += strcspn(bmagic, " ");
923 return strcmp(amagic, bmagic) == 0;
924 }
925 #else
926 static inline int check_version(Elf_Shdr *sechdrs,
927 unsigned int versindex,
928 const char *symname,
929 struct module *mod,
930 const unsigned long *crc)
931 {
932 return 1;
933 }
934
935 static inline int check_modstruct_version(Elf_Shdr *sechdrs,
936 unsigned int versindex,
937 struct module *mod)
938 {
939 return 1;
940 }
941
942 static inline int same_magic(const char *amagic, const char *bmagic)
943 {
944 return strcmp(amagic, bmagic) == 0;
945 }
946 #endif /* CONFIG_MODVERSIONS */
947
948 /* Resolve a symbol for this module. I.e. if we find one, record usage.
949 Must be holding module_mutex. */
950 static unsigned long resolve_symbol(Elf_Shdr *sechdrs,
951 unsigned int versindex,
952 const char *name,
953 struct module *mod)
954 {
955 struct module *owner;
956 unsigned long ret;
957 const unsigned long *crc;
958
959 ret = __find_symbol(name, &owner, &crc,
960 !(mod->taints & TAINT_PROPRIETARY_MODULE));
961 if (ret) {
962 /* use_module can fail due to OOM, or module unloading */
963 if (!check_version(sechdrs, versindex, name, mod, crc) ||
964 !use_module(mod, owner))
965 ret = 0;
966 }
967 return ret;
968 }
969
970
971 /*
972 * /sys/module/foo/sections stuff
973 * J. Corbet <corbet@lwn.net>
974 */
975 #ifdef CONFIG_KALLSYMS
976 static ssize_t module_sect_show(struct module_attribute *mattr,
977 struct module *mod, char *buf)
978 {
979 struct module_sect_attr *sattr =
980 container_of(mattr, struct module_sect_attr, mattr);
981 return sprintf(buf, "0x%lx\n", sattr->address);
982 }
983
984 static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
985 {
986 int section;
987
988 for (section = 0; section < sect_attrs->nsections; section++)
989 kfree(sect_attrs->attrs[section].name);
990 kfree(sect_attrs);
991 }
992
993 static void add_sect_attrs(struct module *mod, unsigned int nsect,
994 char *secstrings, Elf_Shdr *sechdrs)
995 {
996 unsigned int nloaded = 0, i, size[2];
997 struct module_sect_attrs *sect_attrs;
998 struct module_sect_attr *sattr;
999 struct attribute **gattr;
1000
1001 /* Count loaded sections and allocate structures */
1002 for (i = 0; i < nsect; i++)
1003 if (sechdrs[i].sh_flags & SHF_ALLOC)
1004 nloaded++;
1005 size[0] = ALIGN(sizeof(*sect_attrs)
1006 + nloaded * sizeof(sect_attrs->attrs[0]),
1007 sizeof(sect_attrs->grp.attrs[0]));
1008 size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]);
1009 sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
1010 if (sect_attrs == NULL)
1011 return;
1012
1013 /* Setup section attributes. */
1014 sect_attrs->grp.name = "sections";
1015 sect_attrs->grp.attrs = (void *)sect_attrs + size[0];
1016
1017 sect_attrs->nsections = 0;
1018 sattr = &sect_attrs->attrs[0];
1019 gattr = &sect_attrs->grp.attrs[0];
1020 for (i = 0; i < nsect; i++) {
1021 if (! (sechdrs[i].sh_flags & SHF_ALLOC))
1022 continue;
1023 sattr->address = sechdrs[i].sh_addr;
1024 sattr->name = kstrdup(secstrings + sechdrs[i].sh_name,
1025 GFP_KERNEL);
1026 if (sattr->name == NULL)
1027 goto out;
1028 sect_attrs->nsections++;
1029 sattr->mattr.show = module_sect_show;
1030 sattr->mattr.store = NULL;
1031 sattr->mattr.attr.name = sattr->name;
1032 sattr->mattr.attr.owner = mod;
1033 sattr->mattr.attr.mode = S_IRUGO;
1034 *(gattr++) = &(sattr++)->mattr.attr;
1035 }
1036 *gattr = NULL;
1037
1038 if (sysfs_create_group(&mod->mkobj.kobj, &sect_attrs->grp))
1039 goto out;
1040
1041 mod->sect_attrs = sect_attrs;
1042 return;
1043 out:
1044 free_sect_attrs(sect_attrs);
1045 }
1046
1047 static void remove_sect_attrs(struct module *mod)
1048 {
1049 if (mod->sect_attrs) {
1050 sysfs_remove_group(&mod->mkobj.kobj,
1051 &mod->sect_attrs->grp);
1052 /* We are positive that no one is using any sect attrs
1053 * at this point. Deallocate immediately. */
1054 free_sect_attrs(mod->sect_attrs);
1055 mod->sect_attrs = NULL;
1056 }
1057 }
1058
1059 #else
1060
1061 static inline void add_sect_attrs(struct module *mod, unsigned int nsect,
1062 char *sectstrings, Elf_Shdr *sechdrs)
1063 {
1064 }
1065
1066 static inline void remove_sect_attrs(struct module *mod)
1067 {
1068 }
1069 #endif /* CONFIG_KALLSYMS */
1070
1071 #ifdef CONFIG_SYSFS
1072 int module_add_modinfo_attrs(struct module *mod)
1073 {
1074 struct module_attribute *attr;
1075 struct module_attribute *temp_attr;
1076 int error = 0;
1077 int i;
1078
1079 mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
1080 (ARRAY_SIZE(modinfo_attrs) + 1)),
1081 GFP_KERNEL);
1082 if (!mod->modinfo_attrs)
1083 return -ENOMEM;
1084
1085 temp_attr = mod->modinfo_attrs;
1086 for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
1087 if (!attr->test ||
1088 (attr->test && attr->test(mod))) {
1089 memcpy(temp_attr, attr, sizeof(*temp_attr));
1090 temp_attr->attr.owner = mod;
1091 error = sysfs_create_file(&mod->mkobj.kobj,&temp_attr->attr);
1092 ++temp_attr;
1093 }
1094 }
1095 return error;
1096 }
1097
1098 void module_remove_modinfo_attrs(struct module *mod)
1099 {
1100 struct module_attribute *attr;
1101 int i;
1102
1103 for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
1104 /* pick a field to test for end of list */
1105 if (!attr->attr.name)
1106 break;
1107 sysfs_remove_file(&mod->mkobj.kobj,&attr->attr);
1108 if (attr->free)
1109 attr->free(mod);
1110 }
1111 kfree(mod->modinfo_attrs);
1112 }
1113 #endif
1114
1115 #ifdef CONFIG_SYSFS
1116 int mod_sysfs_init(struct module *mod)
1117 {
1118 int err;
1119
1120 if (!module_subsys.kset.subsys) {
1121 printk(KERN_ERR "%s: module_subsys not initialized\n",
1122 mod->name);
1123 err = -EINVAL;
1124 goto out;
1125 }
1126 memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
1127 err = kobject_set_name(&mod->mkobj.kobj, "%s", mod->name);
1128 if (err)
1129 goto out;
1130 kobj_set_kset_s(&mod->mkobj, module_subsys);
1131 mod->mkobj.mod = mod;
1132
1133 kobject_init(&mod->mkobj.kobj);
1134
1135 out:
1136 return err;
1137 }
1138
1139 int mod_sysfs_setup(struct module *mod,
1140 struct kernel_param *kparam,
1141 unsigned int num_params)
1142 {
1143 int err;
1144
1145 /* delay uevent until full sysfs population */
1146 err = kobject_add(&mod->mkobj.kobj);
1147 if (err)
1148 goto out;
1149
1150 mod->holders_dir = kobject_add_dir(&mod->mkobj.kobj, "holders");
1151 if (!mod->holders_dir)
1152 goto out_unreg;
1153
1154 err = module_param_sysfs_setup(mod, kparam, num_params);
1155 if (err)
1156 goto out_unreg_holders;
1157
1158 err = module_add_modinfo_attrs(mod);
1159 if (err)
1160 goto out_unreg_param;
1161
1162 kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
1163 return 0;
1164
1165 out_unreg_param:
1166 module_param_sysfs_remove(mod);
1167 out_unreg_holders:
1168 kobject_unregister(mod->holders_dir);
1169 out_unreg:
1170 kobject_del(&mod->mkobj.kobj);
1171 kobject_put(&mod->mkobj.kobj);
1172 out:
1173 return err;
1174 }
1175 #endif
1176
1177 static void mod_kobject_remove(struct module *mod)
1178 {
1179 module_remove_modinfo_attrs(mod);
1180 module_param_sysfs_remove(mod);
1181 kobject_unregister(mod->mkobj.drivers_dir);
1182 kobject_unregister(mod->holders_dir);
1183 kobject_unregister(&mod->mkobj.kobj);
1184 }
1185
1186 /*
1187 * unlink the module with the whole machine is stopped with interrupts off
1188 * - this defends against kallsyms not taking locks
1189 */
1190 static int __unlink_module(void *_mod)
1191 {
1192 struct module *mod = _mod;
1193 list_del(&mod->list);
1194 return 0;
1195 }
1196
1197 /* Free a module, remove from lists, etc (must hold module mutex). */
1198 static void free_module(struct module *mod)
1199 {
1200 /* Delete from various lists */
1201 stop_machine_run(__unlink_module, mod, NR_CPUS);
1202 remove_sect_attrs(mod);
1203 mod_kobject_remove(mod);
1204
1205 unwind_remove_table(mod->unwind_info, 0);
1206
1207 /* Arch-specific cleanup. */
1208 module_arch_cleanup(mod);
1209
1210 /* Module unload stuff */
1211 module_unload_free(mod);
1212
1213 /* This may be NULL, but that's OK */
1214 module_free(mod, mod->module_init);
1215 kfree(mod->args);
1216 if (mod->percpu)
1217 percpu_modfree(mod->percpu);
1218
1219 /* Free lock-classes: */
1220 lockdep_free_key_range(mod->module_core, mod->core_size);
1221
1222 /* Finally, free the core (containing the module structure) */
1223 module_free(mod, mod->module_core);
1224 }
1225
1226 void *__symbol_get(const char *symbol)
1227 {
1228 struct module *owner;
1229 unsigned long value, flags;
1230 const unsigned long *crc;
1231
1232 spin_lock_irqsave(&modlist_lock, flags);
1233 value = __find_symbol(symbol, &owner, &crc, 1);
1234 if (value && !strong_try_module_get(owner))
1235 value = 0;
1236 spin_unlock_irqrestore(&modlist_lock, flags);
1237
1238 return (void *)value;
1239 }
1240 EXPORT_SYMBOL_GPL(__symbol_get);
1241
1242 /*
1243 * Ensure that an exported symbol [global namespace] does not already exist
1244 * in the Kernel or in some other modules exported symbol table.
1245 */
1246 static int verify_export_symbols(struct module *mod)
1247 {
1248 const char *name = NULL;
1249 unsigned long i, ret = 0;
1250 struct module *owner;
1251 const unsigned long *crc;
1252
1253 for (i = 0; i < mod->num_syms; i++)
1254 if (__find_symbol(mod->syms[i].name, &owner, &crc, 1)) {
1255 name = mod->syms[i].name;
1256 ret = -ENOEXEC;
1257 goto dup;
1258 }
1259
1260 for (i = 0; i < mod->num_gpl_syms; i++)
1261 if (__find_symbol(mod->gpl_syms[i].name, &owner, &crc, 1)) {
1262 name = mod->gpl_syms[i].name;
1263 ret = -ENOEXEC;
1264 goto dup;
1265 }
1266
1267 dup:
1268 if (ret)
1269 printk(KERN_ERR "%s: exports duplicate symbol %s (owned by %s)\n",
1270 mod->name, name, module_name(owner));
1271
1272 return ret;
1273 }
1274
1275 /* Change all symbols so that sh_value encodes the pointer directly. */
1276 static int simplify_symbols(Elf_Shdr *sechdrs,
1277 unsigned int symindex,
1278 const char *strtab,
1279 unsigned int versindex,
1280 unsigned int pcpuindex,
1281 struct module *mod)
1282 {
1283 Elf_Sym *sym = (void *)sechdrs[symindex].sh_addr;
1284 unsigned long secbase;
1285 unsigned int i, n = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
1286 int ret = 0;
1287
1288 for (i = 1; i < n; i++) {
1289 switch (sym[i].st_shndx) {
1290 case SHN_COMMON:
1291 /* We compiled with -fno-common. These are not
1292 supposed to happen. */
1293 DEBUGP("Common symbol: %s\n", strtab + sym[i].st_name);
1294 printk("%s: please compile with -fno-common\n",
1295 mod->name);
1296 ret = -ENOEXEC;
1297 break;
1298
1299 case SHN_ABS:
1300 /* Don't need to do anything */
1301 DEBUGP("Absolute symbol: 0x%08lx\n",
1302 (long)sym[i].st_value);
1303 break;
1304
1305 case SHN_UNDEF:
1306 sym[i].st_value
1307 = resolve_symbol(sechdrs, versindex,
1308 strtab + sym[i].st_name, mod);
1309
1310 /* Ok if resolved. */
1311 if (sym[i].st_value != 0)
1312 break;
1313 /* Ok if weak. */
1314 if (ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
1315 break;
1316
1317 printk(KERN_WARNING "%s: Unknown symbol %s\n",
1318 mod->name, strtab + sym[i].st_name);
1319 ret = -ENOENT;
1320 break;
1321
1322 default:
1323 /* Divert to percpu allocation if a percpu var. */
1324 if (sym[i].st_shndx == pcpuindex)
1325 secbase = (unsigned long)mod->percpu;
1326 else
1327 secbase = sechdrs[sym[i].st_shndx].sh_addr;
1328 sym[i].st_value += secbase;
1329 break;
1330 }
1331 }
1332
1333 return ret;
1334 }
1335
1336 /* Update size with this section: return offset. */
1337 static long get_offset(unsigned long *size, Elf_Shdr *sechdr)
1338 {
1339 long ret;
1340
1341 ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
1342 *size = ret + sechdr->sh_size;
1343 return ret;
1344 }
1345
1346 /* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
1347 might -- code, read-only data, read-write data, small data. Tally
1348 sizes, and place the offsets into sh_entsize fields: high bit means it
1349 belongs in init. */
1350 static void layout_sections(struct module *mod,
1351 const Elf_Ehdr *hdr,
1352 Elf_Shdr *sechdrs,
1353 const char *secstrings)
1354 {
1355 static unsigned long const masks[][2] = {
1356 /* NOTE: all executable code must be the first section
1357 * in this array; otherwise modify the text_size
1358 * finder in the two loops below */
1359 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
1360 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
1361 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
1362 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
1363 };
1364 unsigned int m, i;
1365
1366 for (i = 0; i < hdr->e_shnum; i++)
1367 sechdrs[i].sh_entsize = ~0UL;
1368
1369 DEBUGP("Core section allocation order:\n");
1370 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
1371 for (i = 0; i < hdr->e_shnum; ++i) {
1372 Elf_Shdr *s = &sechdrs[i];
1373
1374 if ((s->sh_flags & masks[m][0]) != masks[m][0]
1375 || (s->sh_flags & masks[m][1])
1376 || s->sh_entsize != ~0UL
1377 || strncmp(secstrings + s->sh_name,
1378 ".init", 5) == 0)
1379 continue;
1380 s->sh_entsize = get_offset(&mod->core_size, s);
1381 DEBUGP("\t%s\n", secstrings + s->sh_name);
1382 }
1383 if (m == 0)
1384 mod->core_text_size = mod->core_size;
1385 }
1386
1387 DEBUGP("Init section allocation order:\n");
1388 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
1389 for (i = 0; i < hdr->e_shnum; ++i) {
1390 Elf_Shdr *s = &sechdrs[i];
1391
1392 if ((s->sh_flags & masks[m][0]) != masks[m][0]
1393 || (s->sh_flags & masks[m][1])
1394 || s->sh_entsize != ~0UL
1395 || strncmp(secstrings + s->sh_name,
1396 ".init", 5) != 0)
1397 continue;
1398 s->sh_entsize = (get_offset(&mod->init_size, s)
1399 | INIT_OFFSET_MASK);
1400 DEBUGP("\t%s\n", secstrings + s->sh_name);
1401 }
1402 if (m == 0)
1403 mod->init_text_size = mod->init_size;
1404 }
1405 }
1406
1407 static void set_license(struct module *mod, const char *license)
1408 {
1409 if (!license)
1410 license = "unspecified";
1411
1412 if (!license_is_gpl_compatible(license)) {
1413 if (!(tainted & TAINT_PROPRIETARY_MODULE))
1414 printk(KERN_WARNING "%s: module license '%s' taints "
1415 "kernel.\n", mod->name, license);
1416 add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
1417 }
1418 }
1419
1420 /* Parse tag=value strings from .modinfo section */
1421 static char *next_string(char *string, unsigned long *secsize)
1422 {
1423 /* Skip non-zero chars */
1424 while (string[0]) {
1425 string++;
1426 if ((*secsize)-- <= 1)
1427 return NULL;
1428 }
1429
1430 /* Skip any zero padding. */
1431 while (!string[0]) {
1432 string++;
1433 if ((*secsize)-- <= 1)
1434 return NULL;
1435 }
1436 return string;
1437 }
1438
1439 static char *get_modinfo(Elf_Shdr *sechdrs,
1440 unsigned int info,
1441 const char *tag)
1442 {
1443 char *p;
1444 unsigned int taglen = strlen(tag);
1445 unsigned long size = sechdrs[info].sh_size;
1446
1447 for (p = (char *)sechdrs[info].sh_addr; p; p = next_string(p, &size)) {
1448 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
1449 return p + taglen + 1;
1450 }
1451 return NULL;
1452 }
1453
1454 static void setup_modinfo(struct module *mod, Elf_Shdr *sechdrs,
1455 unsigned int infoindex)
1456 {
1457 struct module_attribute *attr;
1458 int i;
1459
1460 for (i = 0; (attr = modinfo_attrs[i]); i++) {
1461 if (attr->setup)
1462 attr->setup(mod,
1463 get_modinfo(sechdrs,
1464 infoindex,
1465 attr->attr.name));
1466 }
1467 }
1468
1469 #ifdef CONFIG_KALLSYMS
1470 int is_exported(const char *name, const struct module *mod)
1471 {
1472 if (!mod && lookup_symbol(name, __start___ksymtab, __stop___ksymtab))
1473 return 1;
1474 else
1475 if (mod && lookup_symbol(name, mod->syms, mod->syms + mod->num_syms))
1476 return 1;
1477 else
1478 return 0;
1479 }
1480
1481 /* As per nm */
1482 static char elf_type(const Elf_Sym *sym,
1483 Elf_Shdr *sechdrs,
1484 const char *secstrings,
1485 struct module *mod)
1486 {
1487 if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
1488 if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
1489 return 'v';
1490 else
1491 return 'w';
1492 }
1493 if (sym->st_shndx == SHN_UNDEF)
1494 return 'U';
1495 if (sym->st_shndx == SHN_ABS)
1496 return 'a';
1497 if (sym->st_shndx >= SHN_LORESERVE)
1498 return '?';
1499 if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
1500 return 't';
1501 if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
1502 && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
1503 if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
1504 return 'r';
1505 else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
1506 return 'g';
1507 else
1508 return 'd';
1509 }
1510 if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
1511 if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
1512 return 's';
1513 else
1514 return 'b';
1515 }
1516 if (strncmp(secstrings + sechdrs[sym->st_shndx].sh_name,
1517 ".debug", strlen(".debug")) == 0)
1518 return 'n';
1519 return '?';
1520 }
1521
1522 static void add_kallsyms(struct module *mod,
1523 Elf_Shdr *sechdrs,
1524 unsigned int symindex,
1525 unsigned int strindex,
1526 const char *secstrings)
1527 {
1528 unsigned int i;
1529
1530 mod->symtab = (void *)sechdrs[symindex].sh_addr;
1531 mod->num_symtab = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
1532 mod->strtab = (void *)sechdrs[strindex].sh_addr;
1533
1534 /* Set types up while we still have access to sections. */
1535 for (i = 0; i < mod->num_symtab; i++)
1536 mod->symtab[i].st_info
1537 = elf_type(&mod->symtab[i], sechdrs, secstrings, mod);
1538 }
1539 #else
1540 static inline void add_kallsyms(struct module *mod,
1541 Elf_Shdr *sechdrs,
1542 unsigned int symindex,
1543 unsigned int strindex,
1544 const char *secstrings)
1545 {
1546 }
1547 #endif /* CONFIG_KALLSYMS */
1548
1549 /* Allocate and load the module: note that size of section 0 is always
1550 zero, and we rely on this for optional sections. */
1551 static struct module *load_module(void __user *umod,
1552 unsigned long len,
1553 const char __user *uargs)
1554 {
1555 Elf_Ehdr *hdr;
1556 Elf_Shdr *sechdrs;
1557 char *secstrings, *args, *modmagic, *strtab = NULL;
1558 unsigned int i;
1559 unsigned int symindex = 0;
1560 unsigned int strindex = 0;
1561 unsigned int setupindex;
1562 unsigned int exindex;
1563 unsigned int exportindex;
1564 unsigned int modindex;
1565 unsigned int obsparmindex;
1566 unsigned int infoindex;
1567 unsigned int gplindex;
1568 unsigned int crcindex;
1569 unsigned int gplcrcindex;
1570 unsigned int versindex;
1571 unsigned int pcpuindex;
1572 unsigned int gplfutureindex;
1573 unsigned int gplfuturecrcindex;
1574 unsigned int unwindex = 0;
1575 unsigned int unusedindex;
1576 unsigned int unusedcrcindex;
1577 unsigned int unusedgplindex;
1578 unsigned int unusedgplcrcindex;
1579 struct module *mod;
1580 long err = 0;
1581 void *percpu = NULL, *ptr = NULL; /* Stops spurious gcc warning */
1582 struct exception_table_entry *extable;
1583 mm_segment_t old_fs;
1584
1585 DEBUGP("load_module: umod=%p, len=%lu, uargs=%p\n",
1586 umod, len, uargs);
1587 if (len < sizeof(*hdr))
1588 return ERR_PTR(-ENOEXEC);
1589
1590 /* Suck in entire file: we'll want most of it. */
1591 /* vmalloc barfs on "unusual" numbers. Check here */
1592 if (len > 64 * 1024 * 1024 || (hdr = vmalloc(len)) == NULL)
1593 return ERR_PTR(-ENOMEM);
1594 if (copy_from_user(hdr, umod, len) != 0) {
1595 err = -EFAULT;
1596 goto free_hdr;
1597 }
1598
1599 /* Sanity checks against insmoding binaries or wrong arch,
1600 weird elf version */
1601 if (memcmp(hdr->e_ident, ELFMAG, 4) != 0
1602 || hdr->e_type != ET_REL
1603 || !elf_check_arch(hdr)
1604 || hdr->e_shentsize != sizeof(*sechdrs)) {
1605 err = -ENOEXEC;
1606 goto free_hdr;
1607 }
1608
1609 if (len < hdr->e_shoff + hdr->e_shnum * sizeof(Elf_Shdr))
1610 goto truncated;
1611
1612 /* Convenience variables */
1613 sechdrs = (void *)hdr + hdr->e_shoff;
1614 secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
1615 sechdrs[0].sh_addr = 0;
1616
1617 for (i = 1; i < hdr->e_shnum; i++) {
1618 if (sechdrs[i].sh_type != SHT_NOBITS
1619 && len < sechdrs[i].sh_offset + sechdrs[i].sh_size)
1620 goto truncated;
1621
1622 /* Mark all sections sh_addr with their address in the
1623 temporary image. */
1624 sechdrs[i].sh_addr = (size_t)hdr + sechdrs[i].sh_offset;
1625
1626 /* Internal symbols and strings. */
1627 if (sechdrs[i].sh_type == SHT_SYMTAB) {
1628 symindex = i;
1629 strindex = sechdrs[i].sh_link;
1630 strtab = (char *)hdr + sechdrs[strindex].sh_offset;
1631 }
1632 #ifndef CONFIG_MODULE_UNLOAD
1633 /* Don't load .exit sections */
1634 if (strncmp(secstrings+sechdrs[i].sh_name, ".exit", 5) == 0)
1635 sechdrs[i].sh_flags &= ~(unsigned long)SHF_ALLOC;
1636 #endif
1637 }
1638
1639 modindex = find_sec(hdr, sechdrs, secstrings,
1640 ".gnu.linkonce.this_module");
1641 if (!modindex) {
1642 printk(KERN_WARNING "No module found in object\n");
1643 err = -ENOEXEC;
1644 goto free_hdr;
1645 }
1646 mod = (void *)sechdrs[modindex].sh_addr;
1647
1648 if (symindex == 0) {
1649 printk(KERN_WARNING "%s: module has no symbols (stripped?)\n",
1650 mod->name);
1651 err = -ENOEXEC;
1652 goto free_hdr;
1653 }
1654
1655 /* Optional sections */
1656 exportindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab");
1657 gplindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_gpl");
1658 gplfutureindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_gpl_future");
1659 unusedindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_unused");
1660 unusedgplindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_unused_gpl");
1661 crcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab");
1662 gplcrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_gpl");
1663 gplfuturecrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_gpl_future");
1664 unusedcrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_unused");
1665 unusedgplcrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_unused_gpl");
1666 setupindex = find_sec(hdr, sechdrs, secstrings, "__param");
1667 exindex = find_sec(hdr, sechdrs, secstrings, "__ex_table");
1668 obsparmindex = find_sec(hdr, sechdrs, secstrings, "__obsparm");
1669 versindex = find_sec(hdr, sechdrs, secstrings, "__versions");
1670 infoindex = find_sec(hdr, sechdrs, secstrings, ".modinfo");
1671 pcpuindex = find_pcpusec(hdr, sechdrs, secstrings);
1672 #ifdef ARCH_UNWIND_SECTION_NAME
1673 unwindex = find_sec(hdr, sechdrs, secstrings, ARCH_UNWIND_SECTION_NAME);
1674 #endif
1675
1676 /* Don't keep modinfo section */
1677 sechdrs[infoindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
1678 #ifdef CONFIG_KALLSYMS
1679 /* Keep symbol and string tables for decoding later. */
1680 sechdrs[symindex].sh_flags |= SHF_ALLOC;
1681 sechdrs[strindex].sh_flags |= SHF_ALLOC;
1682 #endif
1683 if (unwindex)
1684 sechdrs[unwindex].sh_flags |= SHF_ALLOC;
1685
1686 /* Check module struct version now, before we try to use module. */
1687 if (!check_modstruct_version(sechdrs, versindex, mod)) {
1688 err = -ENOEXEC;
1689 goto free_hdr;
1690 }
1691
1692 modmagic = get_modinfo(sechdrs, infoindex, "vermagic");
1693 /* This is allowed: modprobe --force will invalidate it. */
1694 if (!modmagic) {
1695 add_taint_module(mod, TAINT_FORCED_MODULE);
1696 printk(KERN_WARNING "%s: no version magic, tainting kernel.\n",
1697 mod->name);
1698 } else if (!same_magic(modmagic, vermagic)) {
1699 printk(KERN_ERR "%s: version magic '%s' should be '%s'\n",
1700 mod->name, modmagic, vermagic);
1701 err = -ENOEXEC;
1702 goto free_hdr;
1703 }
1704
1705 /* Now copy in args */
1706 args = strndup_user(uargs, ~0UL >> 1);
1707 if (IS_ERR(args)) {
1708 err = PTR_ERR(args);
1709 goto free_hdr;
1710 }
1711
1712 if (find_module(mod->name)) {
1713 err = -EEXIST;
1714 goto free_mod;
1715 }
1716
1717 mod->state = MODULE_STATE_COMING;
1718
1719 /* Allow arches to frob section contents and sizes. */
1720 err = module_frob_arch_sections(hdr, sechdrs, secstrings, mod);
1721 if (err < 0)
1722 goto free_mod;
1723
1724 if (pcpuindex) {
1725 /* We have a special allocation for this section. */
1726 percpu = percpu_modalloc(sechdrs[pcpuindex].sh_size,
1727 sechdrs[pcpuindex].sh_addralign,
1728 mod->name);
1729 if (!percpu) {
1730 err = -ENOMEM;
1731 goto free_mod;
1732 }
1733 sechdrs[pcpuindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
1734 mod->percpu = percpu;
1735 }
1736
1737 /* Determine total sizes, and put offsets in sh_entsize. For now
1738 this is done generically; there doesn't appear to be any
1739 special cases for the architectures. */
1740 layout_sections(mod, hdr, sechdrs, secstrings);
1741
1742 /* Do the allocs. */
1743 ptr = module_alloc(mod->core_size);
1744 if (!ptr) {
1745 err = -ENOMEM;
1746 goto free_percpu;
1747 }
1748 memset(ptr, 0, mod->core_size);
1749 mod->module_core = ptr;
1750
1751 ptr = module_alloc(mod->init_size);
1752 if (!ptr && mod->init_size) {
1753 err = -ENOMEM;
1754 goto free_core;
1755 }
1756 memset(ptr, 0, mod->init_size);
1757 mod->module_init = ptr;
1758
1759 /* Transfer each section which specifies SHF_ALLOC */
1760 DEBUGP("final section addresses:\n");
1761 for (i = 0; i < hdr->e_shnum; i++) {
1762 void *dest;
1763
1764 if (!(sechdrs[i].sh_flags & SHF_ALLOC))
1765 continue;
1766
1767 if (sechdrs[i].sh_entsize & INIT_OFFSET_MASK)
1768 dest = mod->module_init
1769 + (sechdrs[i].sh_entsize & ~INIT_OFFSET_MASK);
1770 else
1771 dest = mod->module_core + sechdrs[i].sh_entsize;
1772
1773 if (sechdrs[i].sh_type != SHT_NOBITS)
1774 memcpy(dest, (void *)sechdrs[i].sh_addr,
1775 sechdrs[i].sh_size);
1776 /* Update sh_addr to point to copy in image. */
1777 sechdrs[i].sh_addr = (unsigned long)dest;
1778 DEBUGP("\t0x%lx %s\n", sechdrs[i].sh_addr, secstrings + sechdrs[i].sh_name);
1779 }
1780 /* Module has been moved. */
1781 mod = (void *)sechdrs[modindex].sh_addr;
1782
1783 /* Now we've moved module, initialize linked lists, etc. */
1784 module_unload_init(mod);
1785
1786 /* Initialize kobject, so we can reference it. */
1787 if (mod_sysfs_init(mod) != 0)
1788 goto cleanup;
1789
1790 /* Set up license info based on the info section */
1791 set_license(mod, get_modinfo(sechdrs, infoindex, "license"));
1792
1793 if (strcmp(mod->name, "ndiswrapper") == 0)
1794 add_taint(TAINT_PROPRIETARY_MODULE);
1795 if (strcmp(mod->name, "driverloader") == 0)
1796 add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
1797
1798 /* Set up MODINFO_ATTR fields */
1799 setup_modinfo(mod, sechdrs, infoindex);
1800
1801 /* Fix up syms, so that st_value is a pointer to location. */
1802 err = simplify_symbols(sechdrs, symindex, strtab, versindex, pcpuindex,
1803 mod);
1804 if (err < 0)
1805 goto cleanup;
1806
1807 /* Set up EXPORTed & EXPORT_GPLed symbols (section 0 is 0 length) */
1808 mod->num_syms = sechdrs[exportindex].sh_size / sizeof(*mod->syms);
1809 mod->syms = (void *)sechdrs[exportindex].sh_addr;
1810 if (crcindex)
1811 mod->crcs = (void *)sechdrs[crcindex].sh_addr;
1812 mod->num_gpl_syms = sechdrs[gplindex].sh_size / sizeof(*mod->gpl_syms);
1813 mod->gpl_syms = (void *)sechdrs[gplindex].sh_addr;
1814 if (gplcrcindex)
1815 mod->gpl_crcs = (void *)sechdrs[gplcrcindex].sh_addr;
1816 mod->num_gpl_future_syms = sechdrs[gplfutureindex].sh_size /
1817 sizeof(*mod->gpl_future_syms);
1818 mod->num_unused_syms = sechdrs[unusedindex].sh_size /
1819 sizeof(*mod->unused_syms);
1820 mod->num_unused_gpl_syms = sechdrs[unusedgplindex].sh_size /
1821 sizeof(*mod->unused_gpl_syms);
1822 mod->gpl_future_syms = (void *)sechdrs[gplfutureindex].sh_addr;
1823 if (gplfuturecrcindex)
1824 mod->gpl_future_crcs = (void *)sechdrs[gplfuturecrcindex].sh_addr;
1825
1826 mod->unused_syms = (void *)sechdrs[unusedindex].sh_addr;
1827 if (unusedcrcindex)
1828 mod->unused_crcs = (void *)sechdrs[unusedcrcindex].sh_addr;
1829 mod->unused_gpl_syms = (void *)sechdrs[unusedgplindex].sh_addr;
1830 if (unusedgplcrcindex)
1831 mod->unused_crcs = (void *)sechdrs[unusedgplcrcindex].sh_addr;
1832
1833 #ifdef CONFIG_MODVERSIONS
1834 if ((mod->num_syms && !crcindex) ||
1835 (mod->num_gpl_syms && !gplcrcindex) ||
1836 (mod->num_gpl_future_syms && !gplfuturecrcindex) ||
1837 (mod->num_unused_syms && !unusedcrcindex) ||
1838 (mod->num_unused_gpl_syms && !unusedgplcrcindex)) {
1839 printk(KERN_WARNING "%s: No versions for exported symbols."
1840 " Tainting kernel.\n", mod->name);
1841 add_taint_module(mod, TAINT_FORCED_MODULE);
1842 }
1843 #endif
1844
1845 /* Now do relocations. */
1846 for (i = 1; i < hdr->e_shnum; i++) {
1847 const char *strtab = (char *)sechdrs[strindex].sh_addr;
1848 unsigned int info = sechdrs[i].sh_info;
1849
1850 /* Not a valid relocation section? */
1851 if (info >= hdr->e_shnum)
1852 continue;
1853
1854 /* Don't bother with non-allocated sections */
1855 if (!(sechdrs[info].sh_flags & SHF_ALLOC))
1856 continue;
1857
1858 if (sechdrs[i].sh_type == SHT_REL)
1859 err = apply_relocate(sechdrs, strtab, symindex, i,mod);
1860 else if (sechdrs[i].sh_type == SHT_RELA)
1861 err = apply_relocate_add(sechdrs, strtab, symindex, i,
1862 mod);
1863 if (err < 0)
1864 goto cleanup;
1865 }
1866
1867 /* Find duplicate symbols */
1868 err = verify_export_symbols(mod);
1869
1870 if (err < 0)
1871 goto cleanup;
1872
1873 /* Set up and sort exception table */
1874 mod->num_exentries = sechdrs[exindex].sh_size / sizeof(*mod->extable);
1875 mod->extable = extable = (void *)sechdrs[exindex].sh_addr;
1876 sort_extable(extable, extable + mod->num_exentries);
1877
1878 /* Finally, copy percpu area over. */
1879 percpu_modcopy(mod->percpu, (void *)sechdrs[pcpuindex].sh_addr,
1880 sechdrs[pcpuindex].sh_size);
1881
1882 add_kallsyms(mod, sechdrs, symindex, strindex, secstrings);
1883
1884 err = module_finalize(hdr, sechdrs, mod);
1885 if (err < 0)
1886 goto cleanup;
1887
1888 /* flush the icache in correct context */
1889 old_fs = get_fs();
1890 set_fs(KERNEL_DS);
1891
1892 /*
1893 * Flush the instruction cache, since we've played with text.
1894 * Do it before processing of module parameters, so the module
1895 * can provide parameter accessor functions of its own.
1896 */
1897 if (mod->module_init)
1898 flush_icache_range((unsigned long)mod->module_init,
1899 (unsigned long)mod->module_init
1900 + mod->init_size);
1901 flush_icache_range((unsigned long)mod->module_core,
1902 (unsigned long)mod->module_core + mod->core_size);
1903
1904 set_fs(old_fs);
1905
1906 mod->args = args;
1907 if (obsparmindex)
1908 printk(KERN_WARNING "%s: Ignoring obsolete parameters\n",
1909 mod->name);
1910
1911 /* Size of section 0 is 0, so this works well if no params */
1912 err = parse_args(mod->name, mod->args,
1913 (struct kernel_param *)
1914 sechdrs[setupindex].sh_addr,
1915 sechdrs[setupindex].sh_size
1916 / sizeof(struct kernel_param),
1917 NULL);
1918 if (err < 0)
1919 goto arch_cleanup;
1920
1921 err = mod_sysfs_setup(mod,
1922 (struct kernel_param *)
1923 sechdrs[setupindex].sh_addr,
1924 sechdrs[setupindex].sh_size
1925 / sizeof(struct kernel_param));
1926 if (err < 0)
1927 goto arch_cleanup;
1928 add_sect_attrs(mod, hdr->e_shnum, secstrings, sechdrs);
1929
1930 /* Size of section 0 is 0, so this works well if no unwind info. */
1931 mod->unwind_info = unwind_add_table(mod,
1932 (void *)sechdrs[unwindex].sh_addr,
1933 sechdrs[unwindex].sh_size);
1934
1935 /* Get rid of temporary copy */
1936 vfree(hdr);
1937
1938 /* Done! */
1939 return mod;
1940
1941 arch_cleanup:
1942 module_arch_cleanup(mod);
1943 cleanup:
1944 module_unload_free(mod);
1945 module_free(mod, mod->module_init);
1946 free_core:
1947 module_free(mod, mod->module_core);
1948 free_percpu:
1949 if (percpu)
1950 percpu_modfree(percpu);
1951 free_mod:
1952 kfree(args);
1953 free_hdr:
1954 vfree(hdr);
1955 return ERR_PTR(err);
1956
1957 truncated:
1958 printk(KERN_ERR "Module len %lu truncated\n", len);
1959 err = -ENOEXEC;
1960 goto free_hdr;
1961 }
1962
1963 /*
1964 * link the module with the whole machine is stopped with interrupts off
1965 * - this defends against kallsyms not taking locks
1966 */
1967 static int __link_module(void *_mod)
1968 {
1969 struct module *mod = _mod;
1970 list_add(&mod->list, &modules);
1971 return 0;
1972 }
1973
1974 /* This is where the real work happens */
1975 asmlinkage long
1976 sys_init_module(void __user *umod,
1977 unsigned long len,
1978 const char __user *uargs)
1979 {
1980 struct module *mod;
1981 int ret = 0;
1982
1983 /* Must have permission */
1984 if (!capable(CAP_SYS_MODULE))
1985 return -EPERM;
1986
1987 /* Only one module load at a time, please */
1988 if (mutex_lock_interruptible(&module_mutex) != 0)
1989 return -EINTR;
1990
1991 /* Do all the hard work */
1992 mod = load_module(umod, len, uargs);
1993 if (IS_ERR(mod)) {
1994 mutex_unlock(&module_mutex);
1995 return PTR_ERR(mod);
1996 }
1997
1998 /* Now sew it into the lists. They won't access us, since
1999 strong_try_module_get() will fail. */
2000 stop_machine_run(__link_module, mod, NR_CPUS);
2001
2002 /* Drop lock so they can recurse */
2003 mutex_unlock(&module_mutex);
2004
2005 blocking_notifier_call_chain(&module_notify_list,
2006 MODULE_STATE_COMING, mod);
2007
2008 /* Start the module */
2009 if (mod->init != NULL)
2010 ret = mod->init();
2011 if (ret < 0) {
2012 /* Init routine failed: abort. Try to protect us from
2013 buggy refcounters. */
2014 mod->state = MODULE_STATE_GOING;
2015 synchronize_sched();
2016 if (mod->unsafe)
2017 printk(KERN_ERR "%s: module is now stuck!\n",
2018 mod->name);
2019 else {
2020 module_put(mod);
2021 mutex_lock(&module_mutex);
2022 free_module(mod);
2023 mutex_unlock(&module_mutex);
2024 }
2025 return ret;
2026 }
2027
2028 /* Now it's a first class citizen! */
2029 mutex_lock(&module_mutex);
2030 mod->state = MODULE_STATE_LIVE;
2031 /* Drop initial reference. */
2032 module_put(mod);
2033 unwind_remove_table(mod->unwind_info, 1);
2034 module_free(mod, mod->module_init);
2035 mod->module_init = NULL;
2036 mod->init_size = 0;
2037 mod->init_text_size = 0;
2038 mutex_unlock(&module_mutex);
2039
2040 return 0;
2041 }
2042
2043 static inline int within(unsigned long addr, void *start, unsigned long size)
2044 {
2045 return ((void *)addr >= start && (void *)addr < start + size);
2046 }
2047
2048 #ifdef CONFIG_KALLSYMS
2049 /*
2050 * This ignores the intensely annoying "mapping symbols" found
2051 * in ARM ELF files: $a, $t and $d.
2052 */
2053 static inline int is_arm_mapping_symbol(const char *str)
2054 {
2055 return str[0] == '$' && strchr("atd", str[1])
2056 && (str[2] == '\0' || str[2] == '.');
2057 }
2058
2059 static const char *get_ksymbol(struct module *mod,
2060 unsigned long addr,
2061 unsigned long *size,
2062 unsigned long *offset)
2063 {
2064 unsigned int i, best = 0;
2065 unsigned long nextval;
2066
2067 /* At worse, next value is at end of module */
2068 if (within(addr, mod->module_init, mod->init_size))
2069 nextval = (unsigned long)mod->module_init+mod->init_text_size;
2070 else
2071 nextval = (unsigned long)mod->module_core+mod->core_text_size;
2072
2073 /* Scan for closest preceeding symbol, and next symbol. (ELF
2074 starts real symbols at 1). */
2075 for (i = 1; i < mod->num_symtab; i++) {
2076 if (mod->symtab[i].st_shndx == SHN_UNDEF)
2077 continue;
2078
2079 /* We ignore unnamed symbols: they're uninformative
2080 * and inserted at a whim. */
2081 if (mod->symtab[i].st_value <= addr
2082 && mod->symtab[i].st_value > mod->symtab[best].st_value
2083 && *(mod->strtab + mod->symtab[i].st_name) != '\0'
2084 && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
2085 best = i;
2086 if (mod->symtab[i].st_value > addr
2087 && mod->symtab[i].st_value < nextval
2088 && *(mod->strtab + mod->symtab[i].st_name) != '\0'
2089 && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
2090 nextval = mod->symtab[i].st_value;
2091 }
2092
2093 if (!best)
2094 return NULL;
2095
2096 *size = nextval - mod->symtab[best].st_value;
2097 *offset = addr - mod->symtab[best].st_value;
2098 return mod->strtab + mod->symtab[best].st_name;
2099 }
2100
2101 /* For kallsyms to ask for address resolution. NULL means not found.
2102 We don't lock, as this is used for oops resolution and races are a
2103 lesser concern. */
2104 const char *module_address_lookup(unsigned long addr,
2105 unsigned long *size,
2106 unsigned long *offset,
2107 char **modname)
2108 {
2109 struct module *mod;
2110
2111 list_for_each_entry(mod, &modules, list) {
2112 if (within(addr, mod->module_init, mod->init_size)
2113 || within(addr, mod->module_core, mod->core_size)) {
2114 if (modname)
2115 *modname = mod->name;
2116 return get_ksymbol(mod, addr, size, offset);
2117 }
2118 }
2119 return NULL;
2120 }
2121
2122 struct module *module_get_kallsym(unsigned int symnum, unsigned long *value,
2123 char *type, char *name, size_t namelen)
2124 {
2125 struct module *mod;
2126
2127 mutex_lock(&module_mutex);
2128 list_for_each_entry(mod, &modules, list) {
2129 if (symnum < mod->num_symtab) {
2130 *value = mod->symtab[symnum].st_value;
2131 *type = mod->symtab[symnum].st_info;
2132 strlcpy(name, mod->strtab + mod->symtab[symnum].st_name,
2133 namelen);
2134 mutex_unlock(&module_mutex);
2135 return mod;
2136 }
2137 symnum -= mod->num_symtab;
2138 }
2139 mutex_unlock(&module_mutex);
2140 return NULL;
2141 }
2142
2143 static unsigned long mod_find_symname(struct module *mod, const char *name)
2144 {
2145 unsigned int i;
2146
2147 for (i = 0; i < mod->num_symtab; i++)
2148 if (strcmp(name, mod->strtab+mod->symtab[i].st_name) == 0 &&
2149 mod->symtab[i].st_info != 'U')
2150 return mod->symtab[i].st_value;
2151 return 0;
2152 }
2153
2154 /* Look for this name: can be of form module:name. */
2155 unsigned long module_kallsyms_lookup_name(const char *name)
2156 {
2157 struct module *mod;
2158 char *colon;
2159 unsigned long ret = 0;
2160
2161 /* Don't lock: we're in enough trouble already. */
2162 if ((colon = strchr(name, ':')) != NULL) {
2163 *colon = '\0';
2164 if ((mod = find_module(name)) != NULL)
2165 ret = mod_find_symname(mod, colon+1);
2166 *colon = ':';
2167 } else {
2168 list_for_each_entry(mod, &modules, list)
2169 if ((ret = mod_find_symname(mod, name)) != 0)
2170 break;
2171 }
2172 return ret;
2173 }
2174 #endif /* CONFIG_KALLSYMS */
2175
2176 /* Called by the /proc file system to return a list of modules. */
2177 static void *m_start(struct seq_file *m, loff_t *pos)
2178 {
2179 struct list_head *i;
2180 loff_t n = 0;
2181
2182 mutex_lock(&module_mutex);
2183 list_for_each(i, &modules) {
2184 if (n++ == *pos)
2185 break;
2186 }
2187 if (i == &modules)
2188 return NULL;
2189 return i;
2190 }
2191
2192 static void *m_next(struct seq_file *m, void *p, loff_t *pos)
2193 {
2194 struct list_head *i = p;
2195 (*pos)++;
2196 if (i->next == &modules)
2197 return NULL;
2198 return i->next;
2199 }
2200
2201 static void m_stop(struct seq_file *m, void *p)
2202 {
2203 mutex_unlock(&module_mutex);
2204 }
2205
2206 static char *taint_flags(unsigned int taints, char *buf)
2207 {
2208 int bx = 0;
2209
2210 if (taints) {
2211 buf[bx++] = '(';
2212 if (taints & TAINT_PROPRIETARY_MODULE)
2213 buf[bx++] = 'P';
2214 if (taints & TAINT_FORCED_MODULE)
2215 buf[bx++] = 'F';
2216 /*
2217 * TAINT_FORCED_RMMOD: could be added.
2218 * TAINT_UNSAFE_SMP, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't
2219 * apply to modules.
2220 */
2221 buf[bx++] = ')';
2222 }
2223 buf[bx] = '\0';
2224
2225 return buf;
2226 }
2227
2228 static int m_show(struct seq_file *m, void *p)
2229 {
2230 struct module *mod = list_entry(p, struct module, list);
2231 char buf[8];
2232
2233 seq_printf(m, "%s %lu",
2234 mod->name, mod->init_size + mod->core_size);
2235 print_unload_info(m, mod);
2236
2237 /* Informative for users. */
2238 seq_printf(m, " %s",
2239 mod->state == MODULE_STATE_GOING ? "Unloading":
2240 mod->state == MODULE_STATE_COMING ? "Loading":
2241 "Live");
2242 /* Used by oprofile and other similar tools. */
2243 seq_printf(m, " 0x%p", mod->module_core);
2244
2245 /* Taints info */
2246 if (mod->taints)
2247 seq_printf(m, " %s", taint_flags(mod->taints, buf));
2248
2249 seq_printf(m, "\n");
2250 return 0;
2251 }
2252
2253 /* Format: modulename size refcount deps address
2254
2255 Where refcount is a number or -, and deps is a comma-separated list
2256 of depends or -.
2257 */
2258 const struct seq_operations modules_op = {
2259 .start = m_start,
2260 .next = m_next,
2261 .stop = m_stop,
2262 .show = m_show
2263 };
2264
2265 /* Given an address, look for it in the module exception tables. */
2266 const struct exception_table_entry *search_module_extables(unsigned long addr)
2267 {
2268 unsigned long flags;
2269 const struct exception_table_entry *e = NULL;
2270 struct module *mod;
2271
2272 spin_lock_irqsave(&modlist_lock, flags);
2273 list_for_each_entry(mod, &modules, list) {
2274 if (mod->num_exentries == 0)
2275 continue;
2276
2277 e = search_extable(mod->extable,
2278 mod->extable + mod->num_exentries - 1,
2279 addr);
2280 if (e)
2281 break;
2282 }
2283 spin_unlock_irqrestore(&modlist_lock, flags);
2284
2285 /* Now, if we found one, we are running inside it now, hence
2286 we cannot unload the module, hence no refcnt needed. */
2287 return e;
2288 }
2289
2290 /*
2291 * Is this a valid module address?
2292 */
2293 int is_module_address(unsigned long addr)
2294 {
2295 unsigned long flags;
2296 struct module *mod;
2297
2298 spin_lock_irqsave(&modlist_lock, flags);
2299
2300 list_for_each_entry(mod, &modules, list) {
2301 if (within(addr, mod->module_core, mod->core_size)) {
2302 spin_unlock_irqrestore(&modlist_lock, flags);
2303 return 1;
2304 }
2305 }
2306
2307 spin_unlock_irqrestore(&modlist_lock, flags);
2308
2309 return 0;
2310 }
2311
2312
2313 /* Is this a valid kernel address? We don't grab the lock: we are oopsing. */
2314 struct module *__module_text_address(unsigned long addr)
2315 {
2316 struct module *mod;
2317
2318 list_for_each_entry(mod, &modules, list)
2319 if (within(addr, mod->module_init, mod->init_text_size)
2320 || within(addr, mod->module_core, mod->core_text_size))
2321 return mod;
2322 return NULL;
2323 }
2324
2325 struct module *module_text_address(unsigned long addr)
2326 {
2327 struct module *mod;
2328 unsigned long flags;
2329
2330 spin_lock_irqsave(&modlist_lock, flags);
2331 mod = __module_text_address(addr);
2332 spin_unlock_irqrestore(&modlist_lock, flags);
2333
2334 return mod;
2335 }
2336
2337 /* Don't grab lock, we're oopsing. */
2338 void print_modules(void)
2339 {
2340 struct module *mod;
2341 char buf[8];
2342
2343 printk("Modules linked in:");
2344 list_for_each_entry(mod, &modules, list)
2345 printk(" %s%s", mod->name, taint_flags(mod->taints, buf));
2346 printk("\n");
2347 }
2348
2349 #ifdef CONFIG_SYSFS
2350 static char *make_driver_name(struct device_driver *drv)
2351 {
2352 char *driver_name;
2353
2354 driver_name = kmalloc(strlen(drv->name) + strlen(drv->bus->name) + 2,
2355 GFP_KERNEL);
2356 if (!driver_name)
2357 return NULL;
2358
2359 sprintf(driver_name, "%s:%s", drv->bus->name, drv->name);
2360 return driver_name;
2361 }
2362
2363 static void module_create_drivers_dir(struct module_kobject *mk)
2364 {
2365 if (!mk || mk->drivers_dir)
2366 return;
2367
2368 mk->drivers_dir = kobject_add_dir(&mk->kobj, "drivers");
2369 }
2370
2371 void module_add_driver(struct module *mod, struct device_driver *drv)
2372 {
2373 char *driver_name;
2374 int no_warn;
2375 struct module_kobject *mk = NULL;
2376
2377 if (!drv)
2378 return;
2379
2380 if (mod)
2381 mk = &mod->mkobj;
2382 else if (drv->mod_name) {
2383 struct kobject *mkobj;
2384
2385 /* Lookup built-in module entry in /sys/modules */
2386 mkobj = kset_find_obj(&module_subsys.kset, drv->mod_name);
2387 if (mkobj) {
2388 mk = container_of(mkobj, struct module_kobject, kobj);
2389 /* remember our module structure */
2390 drv->mkobj = mk;
2391 /* kset_find_obj took a reference */
2392 kobject_put(mkobj);
2393 }
2394 }
2395
2396 if (!mk)
2397 return;
2398
2399 /* Don't check return codes; these calls are idempotent */
2400 no_warn = sysfs_create_link(&drv->kobj, &mk->kobj, "module");
2401 driver_name = make_driver_name(drv);
2402 if (driver_name) {
2403 module_create_drivers_dir(mk);
2404 no_warn = sysfs_create_link(mk->drivers_dir, &drv->kobj,
2405 driver_name);
2406 kfree(driver_name);
2407 }
2408 }
2409 EXPORT_SYMBOL(module_add_driver);
2410
2411 void module_remove_driver(struct device_driver *drv)
2412 {
2413 struct module_kobject *mk = NULL;
2414 char *driver_name;
2415
2416 if (!drv)
2417 return;
2418
2419 sysfs_remove_link(&drv->kobj, "module");
2420
2421 if (drv->owner)
2422 mk = &drv->owner->mkobj;
2423 else if (drv->mkobj)
2424 mk = drv->mkobj;
2425 if (mk && mk->drivers_dir) {
2426 driver_name = make_driver_name(drv);
2427 if (driver_name) {
2428 sysfs_remove_link(mk->drivers_dir, driver_name);
2429 kfree(driver_name);
2430 }
2431 }
2432 }
2433 EXPORT_SYMBOL(module_remove_driver);
2434 #endif
2435
2436 #ifdef CONFIG_MODVERSIONS
2437 /* Generate the signature for struct module here, too, for modversions. */
2438 void struct_module(struct module *mod) { return; }
2439 EXPORT_SYMBOL(struct_module);
2440 #endif