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kconfig: centralize the selection of semaphore debugging in lib/Kconfig.debug
[linux-2.6/openmoko-kernel.git] / kernel / module.c
blob9bdbd1217a6f2eec4ed775dd42357acac1f51b82
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 extern int module_sysfs_initialized;
49
50 #if 0
51 #define DEBUGP printk
52 #else
53 #define DEBUGP(fmt , a...)
54 #endif
55
56 #ifndef ARCH_SHF_SMALL
57 #define ARCH_SHF_SMALL 0
58 #endif
59
60 /* If this is set, the section belongs in the init part of the module */
61 #define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
62
63 /* Protects module list */
64 static DEFINE_SPINLOCK(modlist_lock);
65
66 /* List of modules, protected by module_mutex AND modlist_lock */
67 static DEFINE_MUTEX(module_mutex);
68 static LIST_HEAD(modules);
69
70 static BLOCKING_NOTIFIER_HEAD(module_notify_list);
71
72 int register_module_notifier(struct notifier_block * nb)
73 {
74 return blocking_notifier_chain_register(&module_notify_list, nb);
75 }
76 EXPORT_SYMBOL(register_module_notifier);
77
78 int unregister_module_notifier(struct notifier_block * nb)
79 {
80 return blocking_notifier_chain_unregister(&module_notify_list, nb);
81 }
82 EXPORT_SYMBOL(unregister_module_notifier);
83
84 /* We require a truly strong try_module_get() */
85 static inline int strong_try_module_get(struct module *mod)
86 {
87 if (mod && mod->state == MODULE_STATE_COMING)
88 return 0;
89 return try_module_get(mod);
90 }
91
92 static inline void add_taint_module(struct module *mod, unsigned flag)
93 {
94 add_taint(flag);
95 mod->taints |= flag;
96 }
97
98 /* A thread that wants to hold a reference to a module only while it
99 * is running can call ths to safely exit.
100 * nfsd and lockd use this.
101 */
102 void __module_put_and_exit(struct module *mod, long code)
103 {
104 module_put(mod);
105 do_exit(code);
106 }
107 EXPORT_SYMBOL(__module_put_and_exit);
108
109 /* Find a module section: 0 means not found. */
110 static unsigned int find_sec(Elf_Ehdr *hdr,
111 Elf_Shdr *sechdrs,
112 const char *secstrings,
113 const char *name)
114 {
115 unsigned int i;
116
117 for (i = 1; i < hdr->e_shnum; i++)
118 /* Alloc bit cleared means "ignore it." */
119 if ((sechdrs[i].sh_flags & SHF_ALLOC)
120 && strcmp(secstrings+sechdrs[i].sh_name, name) == 0)
121 return i;
122 return 0;
123 }
124
125 /* Provided by the linker */
126 extern const struct kernel_symbol __start___ksymtab[];
127 extern const struct kernel_symbol __stop___ksymtab[];
128 extern const struct kernel_symbol __start___ksymtab_gpl[];
129 extern const struct kernel_symbol __stop___ksymtab_gpl[];
130 extern const struct kernel_symbol __start___ksymtab_gpl_future[];
131 extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
132 extern const struct kernel_symbol __start___ksymtab_unused[];
133 extern const struct kernel_symbol __stop___ksymtab_unused[];
134 extern const struct kernel_symbol __start___ksymtab_unused_gpl[];
135 extern const struct kernel_symbol __stop___ksymtab_unused_gpl[];
136 extern const struct kernel_symbol __start___ksymtab_gpl_future[];
137 extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
138 extern const unsigned long __start___kcrctab[];
139 extern const unsigned long __start___kcrctab_gpl[];
140 extern const unsigned long __start___kcrctab_gpl_future[];
141 extern const unsigned long __start___kcrctab_unused[];
142 extern const unsigned long __start___kcrctab_unused_gpl[];
143
144 #ifndef CONFIG_MODVERSIONS
145 #define symversion(base, idx) NULL
146 #else
147 #define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
148 #endif
149
150 /* lookup symbol in given range of kernel_symbols */
151 static const struct kernel_symbol *lookup_symbol(const char *name,
152 const struct kernel_symbol *start,
153 const struct kernel_symbol *stop)
154 {
155 const struct kernel_symbol *ks = start;
156 for (; ks < stop; ks++)
157 if (strcmp(ks->name, name) == 0)
158 return ks;
159 return NULL;
160 }
161
162 static void printk_unused_warning(const char *name)
163 {
164 printk(KERN_WARNING "Symbol %s is marked as UNUSED, "
165 "however this module is using it.\n", name);
166 printk(KERN_WARNING "This symbol will go away in the future.\n");
167 printk(KERN_WARNING "Please evalute if this is the right api to use, "
168 "and if it really is, submit a report the linux kernel "
169 "mailinglist together with submitting your code for "
170 "inclusion.\n");
171 }
172
173 /* Find a symbol, return value, crc and module which owns it */
174 static unsigned long __find_symbol(const char *name,
175 struct module **owner,
176 const unsigned long **crc,
177 int gplok)
178 {
179 struct module *mod;
180 const struct kernel_symbol *ks;
181
182 /* Core kernel first. */
183 *owner = NULL;
184 ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
185 if (ks) {
186 *crc = symversion(__start___kcrctab, (ks - __start___ksymtab));
187 return ks->value;
188 }
189 if (gplok) {
190 ks = lookup_symbol(name, __start___ksymtab_gpl,
191 __stop___ksymtab_gpl);
192 if (ks) {
193 *crc = symversion(__start___kcrctab_gpl,
194 (ks - __start___ksymtab_gpl));
195 return ks->value;
196 }
197 }
198 ks = lookup_symbol(name, __start___ksymtab_gpl_future,
199 __stop___ksymtab_gpl_future);
200 if (ks) {
201 if (!gplok) {
202 printk(KERN_WARNING "Symbol %s is being used "
203 "by a non-GPL module, which will not "
204 "be allowed in the future\n", name);
205 printk(KERN_WARNING "Please see the file "
206 "Documentation/feature-removal-schedule.txt "
207 "in the kernel source tree for more "
208 "details.\n");
209 }
210 *crc = symversion(__start___kcrctab_gpl_future,
211 (ks - __start___ksymtab_gpl_future));
212 return ks->value;
213 }
214
215 ks = lookup_symbol(name, __start___ksymtab_unused,
216 __stop___ksymtab_unused);
217 if (ks) {
218 printk_unused_warning(name);
219 *crc = symversion(__start___kcrctab_unused,
220 (ks - __start___ksymtab_unused));
221 return ks->value;
222 }
223
224 if (gplok)
225 ks = lookup_symbol(name, __start___ksymtab_unused_gpl,
226 __stop___ksymtab_unused_gpl);
227 if (ks) {
228 printk_unused_warning(name);
229 *crc = symversion(__start___kcrctab_unused_gpl,
230 (ks - __start___ksymtab_unused_gpl));
231 return ks->value;
232 }
233
234 /* Now try modules. */
235 list_for_each_entry(mod, &modules, list) {
236 *owner = mod;
237 ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
238 if (ks) {
239 *crc = symversion(mod->crcs, (ks - mod->syms));
240 return ks->value;
241 }
242
243 if (gplok) {
244 ks = lookup_symbol(name, mod->gpl_syms,
245 mod->gpl_syms + mod->num_gpl_syms);
246 if (ks) {
247 *crc = symversion(mod->gpl_crcs,
248 (ks - mod->gpl_syms));
249 return ks->value;
250 }
251 }
252 ks = lookup_symbol(name, mod->unused_syms, mod->unused_syms + mod->num_unused_syms);
253 if (ks) {
254 printk_unused_warning(name);
255 *crc = symversion(mod->unused_crcs, (ks - mod->unused_syms));
256 return ks->value;
257 }
258
259 if (gplok) {
260 ks = lookup_symbol(name, mod->unused_gpl_syms,
261 mod->unused_gpl_syms + mod->num_unused_gpl_syms);
262 if (ks) {
263 printk_unused_warning(name);
264 *crc = symversion(mod->unused_gpl_crcs,
265 (ks - mod->unused_gpl_syms));
266 return ks->value;
267 }
268 }
269 ks = lookup_symbol(name, mod->gpl_future_syms,
270 (mod->gpl_future_syms +
271 mod->num_gpl_future_syms));
272 if (ks) {
273 if (!gplok) {
274 printk(KERN_WARNING "Symbol %s is being used "
275 "by a non-GPL module, which will not "
276 "be allowed in the future\n", name);
277 printk(KERN_WARNING "Please see the file "
278 "Documentation/feature-removal-schedule.txt "
279 "in the kernel source tree for more "
280 "details.\n");
281 }
282 *crc = symversion(mod->gpl_future_crcs,
283 (ks - mod->gpl_future_syms));
284 return ks->value;
285 }
286 }
287 DEBUGP("Failed to find symbol %s\n", name);
288 return 0;
289 }
290
291 /* Search for module by name: must hold module_mutex. */
292 static struct module *find_module(const char *name)
293 {
294 struct module *mod;
295
296 list_for_each_entry(mod, &modules, list) {
297 if (strcmp(mod->name, name) == 0)
298 return mod;
299 }
300 return NULL;
301 }
302
303 #ifdef CONFIG_SMP
304 /* Number of blocks used and allocated. */
305 static unsigned int pcpu_num_used, pcpu_num_allocated;
306 /* Size of each block. -ve means used. */
307 static int *pcpu_size;
308
309 static int split_block(unsigned int i, unsigned short size)
310 {
311 /* Reallocation required? */
312 if (pcpu_num_used + 1 > pcpu_num_allocated) {
313 int *new;
314
315 new = krealloc(pcpu_size, sizeof(new[0])*pcpu_num_allocated*2,
316 GFP_KERNEL);
317 if (!new)
318 return 0;
319
320 pcpu_num_allocated *= 2;
321 pcpu_size = new;
322 }
323
324 /* Insert a new subblock */
325 memmove(&pcpu_size[i+1], &pcpu_size[i],
326 sizeof(pcpu_size[0]) * (pcpu_num_used - i));
327 pcpu_num_used++;
328
329 pcpu_size[i+1] -= size;
330 pcpu_size[i] = size;
331 return 1;
332 }
333
334 static inline unsigned int block_size(int val)
335 {
336 if (val < 0)
337 return -val;
338 return val;
339 }
340
341 /* Created by linker magic */
342 extern char __per_cpu_start[], __per_cpu_end[];
343
344 static void *percpu_modalloc(unsigned long size, unsigned long align,
345 const char *name)
346 {
347 unsigned long extra;
348 unsigned int i;
349 void *ptr;
350
351 if (align > PAGE_SIZE) {
352 printk(KERN_WARNING "%s: per-cpu alignment %li > %li\n",
353 name, align, PAGE_SIZE);
354 align = PAGE_SIZE;
355 }
356
357 ptr = __per_cpu_start;
358 for (i = 0; i < pcpu_num_used; ptr += block_size(pcpu_size[i]), i++) {
359 /* Extra for alignment requirement. */
360 extra = ALIGN((unsigned long)ptr, align) - (unsigned long)ptr;
361 BUG_ON(i == 0 && extra != 0);
362
363 if (pcpu_size[i] < 0 || pcpu_size[i] < extra + size)
364 continue;
365
366 /* Transfer extra to previous block. */
367 if (pcpu_size[i-1] < 0)
368 pcpu_size[i-1] -= extra;
369 else
370 pcpu_size[i-1] += extra;
371 pcpu_size[i] -= extra;
372 ptr += extra;
373
374 /* Split block if warranted */
375 if (pcpu_size[i] - size > sizeof(unsigned long))
376 if (!split_block(i, size))
377 return NULL;
378
379 /* Mark allocated */
380 pcpu_size[i] = -pcpu_size[i];
381 return ptr;
382 }
383
384 printk(KERN_WARNING "Could not allocate %lu bytes percpu data\n",
385 size);
386 return NULL;
387 }
388
389 static void percpu_modfree(void *freeme)
390 {
391 unsigned int i;
392 void *ptr = __per_cpu_start + block_size(pcpu_size[0]);
393
394 /* First entry is core kernel percpu data. */
395 for (i = 1; i < pcpu_num_used; ptr += block_size(pcpu_size[i]), i++) {
396 if (ptr == freeme) {
397 pcpu_size[i] = -pcpu_size[i];
398 goto free;
399 }
400 }
401 BUG();
402
403 free:
404 /* Merge with previous? */
405 if (pcpu_size[i-1] >= 0) {
406 pcpu_size[i-1] += pcpu_size[i];
407 pcpu_num_used--;
408 memmove(&pcpu_size[i], &pcpu_size[i+1],
409 (pcpu_num_used - i) * sizeof(pcpu_size[0]));
410 i--;
411 }
412 /* Merge with next? */
413 if (i+1 < pcpu_num_used && pcpu_size[i+1] >= 0) {
414 pcpu_size[i] += pcpu_size[i+1];
415 pcpu_num_used--;
416 memmove(&pcpu_size[i+1], &pcpu_size[i+2],
417 (pcpu_num_used - (i+1)) * sizeof(pcpu_size[0]));
418 }
419 }
420
421 static unsigned int find_pcpusec(Elf_Ehdr *hdr,
422 Elf_Shdr *sechdrs,
423 const char *secstrings)
424 {
425 return find_sec(hdr, sechdrs, secstrings, ".data.percpu");
426 }
427
428 static int percpu_modinit(void)
429 {
430 pcpu_num_used = 2;
431 pcpu_num_allocated = 2;
432 pcpu_size = kmalloc(sizeof(pcpu_size[0]) * pcpu_num_allocated,
433 GFP_KERNEL);
434 /* Static in-kernel percpu data (used). */
435 pcpu_size[0] = -(__per_cpu_end-__per_cpu_start);
436 /* Free room. */
437 pcpu_size[1] = PERCPU_ENOUGH_ROOM + pcpu_size[0];
438 if (pcpu_size[1] < 0) {
439 printk(KERN_ERR "No per-cpu room for modules.\n");
440 pcpu_num_used = 1;
441 }
442
443 return 0;
444 }
445 __initcall(percpu_modinit);
446 #else /* ... !CONFIG_SMP */
447 static inline void *percpu_modalloc(unsigned long size, unsigned long align,
448 const char *name)
449 {
450 return NULL;
451 }
452 static inline void percpu_modfree(void *pcpuptr)
453 {
454 BUG();
455 }
456 static inline unsigned int find_pcpusec(Elf_Ehdr *hdr,
457 Elf_Shdr *sechdrs,
458 const char *secstrings)
459 {
460 return 0;
461 }
462 static inline void percpu_modcopy(void *pcpudst, const void *src,
463 unsigned long size)
464 {
465 /* pcpusec should be 0, and size of that section should be 0. */
466 BUG_ON(size != 0);
467 }
468 #endif /* CONFIG_SMP */
469
470 #define MODINFO_ATTR(field) \
471 static void setup_modinfo_##field(struct module *mod, const char *s) \
472 { \
473 mod->field = kstrdup(s, GFP_KERNEL); \
474 } \
475 static ssize_t show_modinfo_##field(struct module_attribute *mattr, \
476 struct module *mod, char *buffer) \
477 { \
478 return sprintf(buffer, "%s\n", mod->field); \
479 } \
480 static int modinfo_##field##_exists(struct module *mod) \
481 { \
482 return mod->field != NULL; \
483 } \
484 static void free_modinfo_##field(struct module *mod) \
485 { \
486 kfree(mod->field); \
487 mod->field = NULL; \
488 } \
489 static struct module_attribute modinfo_##field = { \
490 .attr = { .name = __stringify(field), .mode = 0444, \
491 .owner = THIS_MODULE }, \
492 .show = show_modinfo_##field, \
493 .setup = setup_modinfo_##field, \
494 .test = modinfo_##field##_exists, \
495 .free = free_modinfo_##field, \
496 };
497
498 MODINFO_ATTR(version);
499 MODINFO_ATTR(srcversion);
500
501 #ifdef CONFIG_MODULE_UNLOAD
502 /* Init the unload section of the module. */
503 static void module_unload_init(struct module *mod)
504 {
505 unsigned int i;
506
507 INIT_LIST_HEAD(&mod->modules_which_use_me);
508 for (i = 0; i < NR_CPUS; i++)
509 local_set(&mod->ref[i].count, 0);
510 /* Hold reference count during initialization. */
511 local_set(&mod->ref[raw_smp_processor_id()].count, 1);
512 /* Backwards compatibility macros put refcount during init. */
513 mod->waiter = current;
514 }
515
516 /* modules using other modules */
517 struct module_use
518 {
519 struct list_head list;
520 struct module *module_which_uses;
521 };
522
523 /* Does a already use b? */
524 static int already_uses(struct module *a, struct module *b)
525 {
526 struct module_use *use;
527
528 list_for_each_entry(use, &b->modules_which_use_me, list) {
529 if (use->module_which_uses == a) {
530 DEBUGP("%s uses %s!\n", a->name, b->name);
531 return 1;
532 }
533 }
534 DEBUGP("%s does not use %s!\n", a->name, b->name);
535 return 0;
536 }
537
538 /* Module a uses b */
539 static int use_module(struct module *a, struct module *b)
540 {
541 struct module_use *use;
542 int no_warn;
543
544 if (b == NULL || already_uses(a, b)) return 1;
545
546 if (!strong_try_module_get(b))
547 return 0;
548
549 DEBUGP("Allocating new usage for %s.\n", a->name);
550 use = kmalloc(sizeof(*use), GFP_ATOMIC);
551 if (!use) {
552 printk("%s: out of memory loading\n", a->name);
553 module_put(b);
554 return 0;
555 }
556
557 use->module_which_uses = a;
558 list_add(&use->list, &b->modules_which_use_me);
559 no_warn = sysfs_create_link(b->holders_dir, &a->mkobj.kobj, a->name);
560 return 1;
561 }
562
563 /* Clear the unload stuff of the module. */
564 static void module_unload_free(struct module *mod)
565 {
566 struct module *i;
567
568 list_for_each_entry(i, &modules, list) {
569 struct module_use *use;
570
571 list_for_each_entry(use, &i->modules_which_use_me, list) {
572 if (use->module_which_uses == mod) {
573 DEBUGP("%s unusing %s\n", mod->name, i->name);
574 module_put(i);
575 list_del(&use->list);
576 kfree(use);
577 sysfs_remove_link(i->holders_dir, mod->name);
578 /* There can be at most one match. */
579 break;
580 }
581 }
582 }
583 }
584
585 #ifdef CONFIG_MODULE_FORCE_UNLOAD
586 static inline int try_force_unload(unsigned int flags)
587 {
588 int ret = (flags & O_TRUNC);
589 if (ret)
590 add_taint(TAINT_FORCED_RMMOD);
591 return ret;
592 }
593 #else
594 static inline int try_force_unload(unsigned int flags)
595 {
596 return 0;
597 }
598 #endif /* CONFIG_MODULE_FORCE_UNLOAD */
599
600 struct stopref
601 {
602 struct module *mod;
603 int flags;
604 int *forced;
605 };
606
607 /* Whole machine is stopped with interrupts off when this runs. */
608 static int __try_stop_module(void *_sref)
609 {
610 struct stopref *sref = _sref;
611
612 /* If it's not unused, quit unless we are told to block. */
613 if ((sref->flags & O_NONBLOCK) && module_refcount(sref->mod) != 0) {
614 if (!(*sref->forced = try_force_unload(sref->flags)))
615 return -EWOULDBLOCK;
616 }
617
618 /* Mark it as dying. */
619 sref->mod->state = MODULE_STATE_GOING;
620 return 0;
621 }
622
623 static int try_stop_module(struct module *mod, int flags, int *forced)
624 {
625 struct stopref sref = { mod, flags, forced };
626
627 return stop_machine_run(__try_stop_module, &sref, NR_CPUS);
628 }
629
630 unsigned int module_refcount(struct module *mod)
631 {
632 unsigned int i, total = 0;
633
634 for (i = 0; i < NR_CPUS; i++)
635 total += local_read(&mod->ref[i].count);
636 return total;
637 }
638 EXPORT_SYMBOL(module_refcount);
639
640 /* This exists whether we can unload or not */
641 static void free_module(struct module *mod);
642
643 static void wait_for_zero_refcount(struct module *mod)
644 {
645 /* Since we might sleep for some time, drop the semaphore first */
646 mutex_unlock(&module_mutex);
647 for (;;) {
648 DEBUGP("Looking at refcount...\n");
649 set_current_state(TASK_UNINTERRUPTIBLE);
650 if (module_refcount(mod) == 0)
651 break;
652 schedule();
653 }
654 current->state = TASK_RUNNING;
655 mutex_lock(&module_mutex);
656 }
657
658 asmlinkage long
659 sys_delete_module(const char __user *name_user, unsigned int flags)
660 {
661 struct module *mod;
662 char name[MODULE_NAME_LEN];
663 int ret, forced = 0;
664
665 if (!capable(CAP_SYS_MODULE))
666 return -EPERM;
667
668 if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
669 return -EFAULT;
670 name[MODULE_NAME_LEN-1] = '\0';
671
672 if (mutex_lock_interruptible(&module_mutex) != 0)
673 return -EINTR;
674
675 mod = find_module(name);
676 if (!mod) {
677 ret = -ENOENT;
678 goto out;
679 }
680
681 if (!list_empty(&mod->modules_which_use_me)) {
682 /* Other modules depend on us: get rid of them first. */
683 ret = -EWOULDBLOCK;
684 goto out;
685 }
686
687 /* Doing init or already dying? */
688 if (mod->state != MODULE_STATE_LIVE) {
689 /* FIXME: if (force), slam module count and wake up
690 waiter --RR */
691 DEBUGP("%s already dying\n", mod->name);
692 ret = -EBUSY;
693 goto out;
694 }
695
696 /* If it has an init func, it must have an exit func to unload */
697 if ((mod->init != NULL && mod->exit == NULL)
698 || mod->unsafe) {
699 forced = try_force_unload(flags);
700 if (!forced) {
701 /* This module can't be removed */
702 ret = -EBUSY;
703 goto out;
704 }
705 }
706
707 /* Set this up before setting mod->state */
708 mod->waiter = current;
709
710 /* Stop the machine so refcounts can't move and disable module. */
711 ret = try_stop_module(mod, flags, &forced);
712 if (ret != 0)
713 goto out;
714
715 /* Never wait if forced. */
716 if (!forced && module_refcount(mod) != 0)
717 wait_for_zero_refcount(mod);
718
719 /* Final destruction now noone is using it. */
720 if (mod->exit != NULL) {
721 mutex_unlock(&module_mutex);
722 mod->exit();
723 mutex_lock(&module_mutex);
724 }
725 free_module(mod);
726
727 out:
728 mutex_unlock(&module_mutex);
729 return ret;
730 }
731
732 static void print_unload_info(struct seq_file *m, struct module *mod)
733 {
734 struct module_use *use;
735 int printed_something = 0;
736
737 seq_printf(m, " %u ", module_refcount(mod));
738
739 /* Always include a trailing , so userspace can differentiate
740 between this and the old multi-field proc format. */
741 list_for_each_entry(use, &mod->modules_which_use_me, list) {
742 printed_something = 1;
743 seq_printf(m, "%s,", use->module_which_uses->name);
744 }
745
746 if (mod->unsafe) {
747 printed_something = 1;
748 seq_printf(m, "[unsafe],");
749 }
750
751 if (mod->init != NULL && mod->exit == NULL) {
752 printed_something = 1;
753 seq_printf(m, "[permanent],");
754 }
755
756 if (!printed_something)
757 seq_printf(m, "-");
758 }
759
760 void __symbol_put(const char *symbol)
761 {
762 struct module *owner;
763 unsigned long flags;
764 const unsigned long *crc;
765
766 spin_lock_irqsave(&modlist_lock, flags);
767 if (!__find_symbol(symbol, &owner, &crc, 1))
768 BUG();
769 module_put(owner);
770 spin_unlock_irqrestore(&modlist_lock, flags);
771 }
772 EXPORT_SYMBOL(__symbol_put);
773
774 void symbol_put_addr(void *addr)
775 {
776 struct module *modaddr;
777
778 if (core_kernel_text((unsigned long)addr))
779 return;
780
781 if (!(modaddr = module_text_address((unsigned long)addr)))
782 BUG();
783 module_put(modaddr);
784 }
785 EXPORT_SYMBOL_GPL(symbol_put_addr);
786
787 static ssize_t show_refcnt(struct module_attribute *mattr,
788 struct module *mod, char *buffer)
789 {
790 /* sysfs holds a reference */
791 return sprintf(buffer, "%u\n", module_refcount(mod)-1);
792 }
793
794 static struct module_attribute refcnt = {
795 .attr = { .name = "refcnt", .mode = 0444, .owner = THIS_MODULE },
796 .show = show_refcnt,
797 };
798
799 void module_put(struct module *module)
800 {
801 if (module) {
802 unsigned int cpu = get_cpu();
803 local_dec(&module->ref[cpu].count);
804 /* Maybe they're waiting for us to drop reference? */
805 if (unlikely(!module_is_live(module)))
806 wake_up_process(module->waiter);
807 put_cpu();
808 }
809 }
810 EXPORT_SYMBOL(module_put);
811
812 #else /* !CONFIG_MODULE_UNLOAD */
813 static void print_unload_info(struct seq_file *m, struct module *mod)
814 {
815 /* We don't know the usage count, or what modules are using. */
816 seq_printf(m, " - -");
817 }
818
819 static inline void module_unload_free(struct module *mod)
820 {
821 }
822
823 static inline int use_module(struct module *a, struct module *b)
824 {
825 return strong_try_module_get(b);
826 }
827
828 static inline void module_unload_init(struct module *mod)
829 {
830 }
831 #endif /* CONFIG_MODULE_UNLOAD */
832
833 static ssize_t show_initstate(struct module_attribute *mattr,
834 struct module *mod, char *buffer)
835 {
836 const char *state = "unknown";
837
838 switch (mod->state) {
839 case MODULE_STATE_LIVE:
840 state = "live";
841 break;
842 case MODULE_STATE_COMING:
843 state = "coming";
844 break;
845 case MODULE_STATE_GOING:
846 state = "going";
847 break;
848 }
849 return sprintf(buffer, "%s\n", state);
850 }
851
852 static struct module_attribute initstate = {
853 .attr = { .name = "initstate", .mode = 0444, .owner = THIS_MODULE },
854 .show = show_initstate,
855 };
856
857 static struct module_attribute *modinfo_attrs[] = {
858 &modinfo_version,
859 &modinfo_srcversion,
860 &initstate,
861 #ifdef CONFIG_MODULE_UNLOAD
862 &refcnt,
863 #endif
864 NULL,
865 };
866
867 static const char vermagic[] = VERMAGIC_STRING;
868
869 #ifdef CONFIG_MODVERSIONS
870 static int check_version(Elf_Shdr *sechdrs,
871 unsigned int versindex,
872 const char *symname,
873 struct module *mod,
874 const unsigned long *crc)
875 {
876 unsigned int i, num_versions;
877 struct modversion_info *versions;
878
879 /* Exporting module didn't supply crcs? OK, we're already tainted. */
880 if (!crc)
881 return 1;
882
883 versions = (void *) sechdrs[versindex].sh_addr;
884 num_versions = sechdrs[versindex].sh_size
885 / sizeof(struct modversion_info);
886
887 for (i = 0; i < num_versions; i++) {
888 if (strcmp(versions[i].name, symname) != 0)
889 continue;
890
891 if (versions[i].crc == *crc)
892 return 1;
893 printk("%s: disagrees about version of symbol %s\n",
894 mod->name, symname);
895 DEBUGP("Found checksum %lX vs module %lX\n",
896 *crc, versions[i].crc);
897 return 0;
898 }
899 /* Not in module's version table. OK, but that taints the kernel. */
900 if (!(tainted & TAINT_FORCED_MODULE))
901 printk("%s: no version for \"%s\" found: kernel tainted.\n",
902 mod->name, symname);
903 add_taint_module(mod, TAINT_FORCED_MODULE);
904 return 1;
905 }
906
907 static inline int check_modstruct_version(Elf_Shdr *sechdrs,
908 unsigned int versindex,
909 struct module *mod)
910 {
911 const unsigned long *crc;
912 struct module *owner;
913
914 if (!__find_symbol("struct_module", &owner, &crc, 1))
915 BUG();
916 return check_version(sechdrs, versindex, "struct_module", mod,
917 crc);
918 }
919
920 /* First part is kernel version, which we ignore. */
921 static inline int same_magic(const char *amagic, const char *bmagic)
922 {
923 amagic += strcspn(amagic, " ");
924 bmagic += strcspn(bmagic, " ");
925 return strcmp(amagic, bmagic) == 0;
926 }
927 #else
928 static inline int check_version(Elf_Shdr *sechdrs,
929 unsigned int versindex,
930 const char *symname,
931 struct module *mod,
932 const unsigned long *crc)
933 {
934 return 1;
935 }
936
937 static inline int check_modstruct_version(Elf_Shdr *sechdrs,
938 unsigned int versindex,
939 struct module *mod)
940 {
941 return 1;
942 }
943
944 static inline int same_magic(const char *amagic, const char *bmagic)
945 {
946 return strcmp(amagic, bmagic) == 0;
947 }
948 #endif /* CONFIG_MODVERSIONS */
949
950 /* Resolve a symbol for this module. I.e. if we find one, record usage.
951 Must be holding module_mutex. */
952 static unsigned long resolve_symbol(Elf_Shdr *sechdrs,
953 unsigned int versindex,
954 const char *name,
955 struct module *mod)
956 {
957 struct module *owner;
958 unsigned long ret;
959 const unsigned long *crc;
960
961 ret = __find_symbol(name, &owner, &crc,
962 !(mod->taints & TAINT_PROPRIETARY_MODULE));
963 if (ret) {
964 /* use_module can fail due to OOM, or module unloading */
965 if (!check_version(sechdrs, versindex, name, mod, crc) ||
966 !use_module(mod, owner))
967 ret = 0;
968 }
969 return ret;
970 }
971
972
973 /*
974 * /sys/module/foo/sections stuff
975 * J. Corbet <corbet@lwn.net>
976 */
977 #ifdef CONFIG_KALLSYMS
978 static ssize_t module_sect_show(struct module_attribute *mattr,
979 struct module *mod, char *buf)
980 {
981 struct module_sect_attr *sattr =
982 container_of(mattr, struct module_sect_attr, mattr);
983 return sprintf(buf, "0x%lx\n", sattr->address);
984 }
985
986 static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
987 {
988 int section;
989
990 for (section = 0; section < sect_attrs->nsections; section++)
991 kfree(sect_attrs->attrs[section].name);
992 kfree(sect_attrs);
993 }
994
995 static void add_sect_attrs(struct module *mod, unsigned int nsect,
996 char *secstrings, Elf_Shdr *sechdrs)
997 {
998 unsigned int nloaded = 0, i, size[2];
999 struct module_sect_attrs *sect_attrs;
1000 struct module_sect_attr *sattr;
1001 struct attribute **gattr;
1002
1003 /* Count loaded sections and allocate structures */
1004 for (i = 0; i < nsect; i++)
1005 if (sechdrs[i].sh_flags & SHF_ALLOC)
1006 nloaded++;
1007 size[0] = ALIGN(sizeof(*sect_attrs)
1008 + nloaded * sizeof(sect_attrs->attrs[0]),
1009 sizeof(sect_attrs->grp.attrs[0]));
1010 size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]);
1011 sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
1012 if (sect_attrs == NULL)
1013 return;
1014
1015 /* Setup section attributes. */
1016 sect_attrs->grp.name = "sections";
1017 sect_attrs->grp.attrs = (void *)sect_attrs + size[0];
1018
1019 sect_attrs->nsections = 0;
1020 sattr = &sect_attrs->attrs[0];
1021 gattr = &sect_attrs->grp.attrs[0];
1022 for (i = 0; i < nsect; i++) {
1023 if (! (sechdrs[i].sh_flags & SHF_ALLOC))
1024 continue;
1025 sattr->address = sechdrs[i].sh_addr;
1026 sattr->name = kstrdup(secstrings + sechdrs[i].sh_name,
1027 GFP_KERNEL);
1028 if (sattr->name == NULL)
1029 goto out;
1030 sect_attrs->nsections++;
1031 sattr->mattr.show = module_sect_show;
1032 sattr->mattr.store = NULL;
1033 sattr->mattr.attr.name = sattr->name;
1034 sattr->mattr.attr.owner = mod;
1035 sattr->mattr.attr.mode = S_IRUGO;
1036 *(gattr++) = &(sattr++)->mattr.attr;
1037 }
1038 *gattr = NULL;
1039
1040 if (sysfs_create_group(&mod->mkobj.kobj, &sect_attrs->grp))
1041 goto out;
1042
1043 mod->sect_attrs = sect_attrs;
1044 return;
1045 out:
1046 free_sect_attrs(sect_attrs);
1047 }
1048
1049 static void remove_sect_attrs(struct module *mod)
1050 {
1051 if (mod->sect_attrs) {
1052 sysfs_remove_group(&mod->mkobj.kobj,
1053 &mod->sect_attrs->grp);
1054 /* We are positive that no one is using any sect attrs
1055 * at this point. Deallocate immediately. */
1056 free_sect_attrs(mod->sect_attrs);
1057 mod->sect_attrs = NULL;
1058 }
1059 }
1060
1061 #else
1062
1063 static inline void add_sect_attrs(struct module *mod, unsigned int nsect,
1064 char *sectstrings, Elf_Shdr *sechdrs)
1065 {
1066 }
1067
1068 static inline void remove_sect_attrs(struct module *mod)
1069 {
1070 }
1071 #endif /* CONFIG_KALLSYMS */
1072
1073 #ifdef CONFIG_SYSFS
1074 int module_add_modinfo_attrs(struct module *mod)
1075 {
1076 struct module_attribute *attr;
1077 struct module_attribute *temp_attr;
1078 int error = 0;
1079 int i;
1080
1081 mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
1082 (ARRAY_SIZE(modinfo_attrs) + 1)),
1083 GFP_KERNEL);
1084 if (!mod->modinfo_attrs)
1085 return -ENOMEM;
1086
1087 temp_attr = mod->modinfo_attrs;
1088 for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
1089 if (!attr->test ||
1090 (attr->test && attr->test(mod))) {
1091 memcpy(temp_attr, attr, sizeof(*temp_attr));
1092 temp_attr->attr.owner = mod;
1093 error = sysfs_create_file(&mod->mkobj.kobj,&temp_attr->attr);
1094 ++temp_attr;
1095 }
1096 }
1097 return error;
1098 }
1099
1100 void module_remove_modinfo_attrs(struct module *mod)
1101 {
1102 struct module_attribute *attr;
1103 int i;
1104
1105 for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
1106 /* pick a field to test for end of list */
1107 if (!attr->attr.name)
1108 break;
1109 sysfs_remove_file(&mod->mkobj.kobj,&attr->attr);
1110 if (attr->free)
1111 attr->free(mod);
1112 }
1113 kfree(mod->modinfo_attrs);
1114 }
1115 #endif
1116
1117 #ifdef CONFIG_SYSFS
1118 int mod_sysfs_init(struct module *mod)
1119 {
1120 int err;
1121
1122 if (!module_sysfs_initialized) {
1123 printk(KERN_ERR "%s: module sysfs not initialized\n",
1124 mod->name);
1125 err = -EINVAL;
1126 goto out;
1127 }
1128 memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
1129 err = kobject_set_name(&mod->mkobj.kobj, "%s", mod->name);
1130 if (err)
1131 goto out;
1132 kobj_set_kset_s(&mod->mkobj, module_subsys);
1133 mod->mkobj.mod = mod;
1134
1135 kobject_init(&mod->mkobj.kobj);
1136
1137 out:
1138 return err;
1139 }
1140
1141 int mod_sysfs_setup(struct module *mod,
1142 struct kernel_param *kparam,
1143 unsigned int num_params)
1144 {
1145 int err;
1146
1147 /* delay uevent until full sysfs population */
1148 err = kobject_add(&mod->mkobj.kobj);
1149 if (err)
1150 goto out;
1151
1152 mod->holders_dir = kobject_add_dir(&mod->mkobj.kobj, "holders");
1153 if (!mod->holders_dir) {
1154 err = -ENOMEM;
1155 goto out_unreg;
1156 }
1157
1158 err = module_param_sysfs_setup(mod, kparam, num_params);
1159 if (err)
1160 goto out_unreg_holders;
1161
1162 err = module_add_modinfo_attrs(mod);
1163 if (err)
1164 goto out_unreg_param;
1165
1166 kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
1167 return 0;
1168
1169 out_unreg_param:
1170 module_param_sysfs_remove(mod);
1171 out_unreg_holders:
1172 kobject_unregister(mod->holders_dir);
1173 out_unreg:
1174 kobject_del(&mod->mkobj.kobj);
1175 kobject_put(&mod->mkobj.kobj);
1176 out:
1177 return err;
1178 }
1179 #endif
1180
1181 static void mod_kobject_remove(struct module *mod)
1182 {
1183 module_remove_modinfo_attrs(mod);
1184 module_param_sysfs_remove(mod);
1185 kobject_unregister(mod->mkobj.drivers_dir);
1186 kobject_unregister(mod->holders_dir);
1187 kobject_unregister(&mod->mkobj.kobj);
1188 }
1189
1190 /*
1191 * unlink the module with the whole machine is stopped with interrupts off
1192 * - this defends against kallsyms not taking locks
1193 */
1194 static int __unlink_module(void *_mod)
1195 {
1196 struct module *mod = _mod;
1197 list_del(&mod->list);
1198 return 0;
1199 }
1200
1201 /* Free a module, remove from lists, etc (must hold module mutex). */
1202 static void free_module(struct module *mod)
1203 {
1204 /* Delete from various lists */
1205 stop_machine_run(__unlink_module, mod, NR_CPUS);
1206 remove_sect_attrs(mod);
1207 mod_kobject_remove(mod);
1208
1209 unwind_remove_table(mod->unwind_info, 0);
1210
1211 /* Arch-specific cleanup. */
1212 module_arch_cleanup(mod);
1213
1214 /* Module unload stuff */
1215 module_unload_free(mod);
1216
1217 /* This may be NULL, but that's OK */
1218 module_free(mod, mod->module_init);
1219 kfree(mod->args);
1220 if (mod->percpu)
1221 percpu_modfree(mod->percpu);
1222
1223 /* Free lock-classes: */
1224 lockdep_free_key_range(mod->module_core, mod->core_size);
1225
1226 /* Finally, free the core (containing the module structure) */
1227 module_free(mod, mod->module_core);
1228 }
1229
1230 void *__symbol_get(const char *symbol)
1231 {
1232 struct module *owner;
1233 unsigned long value, flags;
1234 const unsigned long *crc;
1235
1236 spin_lock_irqsave(&modlist_lock, flags);
1237 value = __find_symbol(symbol, &owner, &crc, 1);
1238 if (value && !strong_try_module_get(owner))
1239 value = 0;
1240 spin_unlock_irqrestore(&modlist_lock, flags);
1241
1242 return (void *)value;
1243 }
1244 EXPORT_SYMBOL_GPL(__symbol_get);
1245
1246 /*
1247 * Ensure that an exported symbol [global namespace] does not already exist
1248 * in the Kernel or in some other modules exported symbol table.
1249 */
1250 static int verify_export_symbols(struct module *mod)
1251 {
1252 const char *name = NULL;
1253 unsigned long i, ret = 0;
1254 struct module *owner;
1255 const unsigned long *crc;
1256
1257 for (i = 0; i < mod->num_syms; i++)
1258 if (__find_symbol(mod->syms[i].name, &owner, &crc, 1)) {
1259 name = mod->syms[i].name;
1260 ret = -ENOEXEC;
1261 goto dup;
1262 }
1263
1264 for (i = 0; i < mod->num_gpl_syms; i++)
1265 if (__find_symbol(mod->gpl_syms[i].name, &owner, &crc, 1)) {
1266 name = mod->gpl_syms[i].name;
1267 ret = -ENOEXEC;
1268 goto dup;
1269 }
1270
1271 dup:
1272 if (ret)
1273 printk(KERN_ERR "%s: exports duplicate symbol %s (owned by %s)\n",
1274 mod->name, name, module_name(owner));
1275
1276 return ret;
1277 }
1278
1279 /* Change all symbols so that sh_value encodes the pointer directly. */
1280 static int simplify_symbols(Elf_Shdr *sechdrs,
1281 unsigned int symindex,
1282 const char *strtab,
1283 unsigned int versindex,
1284 unsigned int pcpuindex,
1285 struct module *mod)
1286 {
1287 Elf_Sym *sym = (void *)sechdrs[symindex].sh_addr;
1288 unsigned long secbase;
1289 unsigned int i, n = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
1290 int ret = 0;
1291
1292 for (i = 1; i < n; i++) {
1293 switch (sym[i].st_shndx) {
1294 case SHN_COMMON:
1295 /* We compiled with -fno-common. These are not
1296 supposed to happen. */
1297 DEBUGP("Common symbol: %s\n", strtab + sym[i].st_name);
1298 printk("%s: please compile with -fno-common\n",
1299 mod->name);
1300 ret = -ENOEXEC;
1301 break;
1302
1303 case SHN_ABS:
1304 /* Don't need to do anything */
1305 DEBUGP("Absolute symbol: 0x%08lx\n",
1306 (long)sym[i].st_value);
1307 break;
1308
1309 case SHN_UNDEF:
1310 sym[i].st_value
1311 = resolve_symbol(sechdrs, versindex,
1312 strtab + sym[i].st_name, mod);
1313
1314 /* Ok if resolved. */
1315 if (sym[i].st_value != 0)
1316 break;
1317 /* Ok if weak. */
1318 if (ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
1319 break;
1320
1321 printk(KERN_WARNING "%s: Unknown symbol %s\n",
1322 mod->name, strtab + sym[i].st_name);
1323 ret = -ENOENT;
1324 break;
1325
1326 default:
1327 /* Divert to percpu allocation if a percpu var. */
1328 if (sym[i].st_shndx == pcpuindex)
1329 secbase = (unsigned long)mod->percpu;
1330 else
1331 secbase = sechdrs[sym[i].st_shndx].sh_addr;
1332 sym[i].st_value += secbase;
1333 break;
1334 }
1335 }
1336
1337 return ret;
1338 }
1339
1340 /* Update size with this section: return offset. */
1341 static long get_offset(unsigned long *size, Elf_Shdr *sechdr)
1342 {
1343 long ret;
1344
1345 ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
1346 *size = ret + sechdr->sh_size;
1347 return ret;
1348 }
1349
1350 /* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
1351 might -- code, read-only data, read-write data, small data. Tally
1352 sizes, and place the offsets into sh_entsize fields: high bit means it
1353 belongs in init. */
1354 static void layout_sections(struct module *mod,
1355 const Elf_Ehdr *hdr,
1356 Elf_Shdr *sechdrs,
1357 const char *secstrings)
1358 {
1359 static unsigned long const masks[][2] = {
1360 /* NOTE: all executable code must be the first section
1361 * in this array; otherwise modify the text_size
1362 * finder in the two loops below */
1363 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
1364 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
1365 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
1366 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
1367 };
1368 unsigned int m, i;
1369
1370 for (i = 0; i < hdr->e_shnum; i++)
1371 sechdrs[i].sh_entsize = ~0UL;
1372
1373 DEBUGP("Core section allocation order:\n");
1374 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
1375 for (i = 0; i < hdr->e_shnum; ++i) {
1376 Elf_Shdr *s = &sechdrs[i];
1377
1378 if ((s->sh_flags & masks[m][0]) != masks[m][0]
1379 || (s->sh_flags & masks[m][1])
1380 || s->sh_entsize != ~0UL
1381 || strncmp(secstrings + s->sh_name,
1382 ".init", 5) == 0)
1383 continue;
1384 s->sh_entsize = get_offset(&mod->core_size, s);
1385 DEBUGP("\t%s\n", secstrings + s->sh_name);
1386 }
1387 if (m == 0)
1388 mod->core_text_size = mod->core_size;
1389 }
1390
1391 DEBUGP("Init section allocation order:\n");
1392 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
1393 for (i = 0; i < hdr->e_shnum; ++i) {
1394 Elf_Shdr *s = &sechdrs[i];
1395
1396 if ((s->sh_flags & masks[m][0]) != masks[m][0]
1397 || (s->sh_flags & masks[m][1])
1398 || s->sh_entsize != ~0UL
1399 || strncmp(secstrings + s->sh_name,
1400 ".init", 5) != 0)
1401 continue;
1402 s->sh_entsize = (get_offset(&mod->init_size, s)
1403 | INIT_OFFSET_MASK);
1404 DEBUGP("\t%s\n", secstrings + s->sh_name);
1405 }
1406 if (m == 0)
1407 mod->init_text_size = mod->init_size;
1408 }
1409 }
1410
1411 static void set_license(struct module *mod, const char *license)
1412 {
1413 if (!license)
1414 license = "unspecified";
1415
1416 if (!license_is_gpl_compatible(license)) {
1417 if (!(tainted & TAINT_PROPRIETARY_MODULE))
1418 printk(KERN_WARNING "%s: module license '%s' taints "
1419 "kernel.\n", mod->name, license);
1420 add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
1421 }
1422 }
1423
1424 /* Parse tag=value strings from .modinfo section */
1425 static char *next_string(char *string, unsigned long *secsize)
1426 {
1427 /* Skip non-zero chars */
1428 while (string[0]) {
1429 string++;
1430 if ((*secsize)-- <= 1)
1431 return NULL;
1432 }
1433
1434 /* Skip any zero padding. */
1435 while (!string[0]) {
1436 string++;
1437 if ((*secsize)-- <= 1)
1438 return NULL;
1439 }
1440 return string;
1441 }
1442
1443 static char *get_modinfo(Elf_Shdr *sechdrs,
1444 unsigned int info,
1445 const char *tag)
1446 {
1447 char *p;
1448 unsigned int taglen = strlen(tag);
1449 unsigned long size = sechdrs[info].sh_size;
1450
1451 for (p = (char *)sechdrs[info].sh_addr; p; p = next_string(p, &size)) {
1452 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
1453 return p + taglen + 1;
1454 }
1455 return NULL;
1456 }
1457
1458 static void setup_modinfo(struct module *mod, Elf_Shdr *sechdrs,
1459 unsigned int infoindex)
1460 {
1461 struct module_attribute *attr;
1462 int i;
1463
1464 for (i = 0; (attr = modinfo_attrs[i]); i++) {
1465 if (attr->setup)
1466 attr->setup(mod,
1467 get_modinfo(sechdrs,
1468 infoindex,
1469 attr->attr.name));
1470 }
1471 }
1472
1473 #ifdef CONFIG_KALLSYMS
1474 int is_exported(const char *name, const struct module *mod)
1475 {
1476 if (!mod && lookup_symbol(name, __start___ksymtab, __stop___ksymtab))
1477 return 1;
1478 else
1479 if (mod && lookup_symbol(name, mod->syms, mod->syms + mod->num_syms))
1480 return 1;
1481 else
1482 return 0;
1483 }
1484
1485 /* As per nm */
1486 static char elf_type(const Elf_Sym *sym,
1487 Elf_Shdr *sechdrs,
1488 const char *secstrings,
1489 struct module *mod)
1490 {
1491 if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
1492 if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
1493 return 'v';
1494 else
1495 return 'w';
1496 }
1497 if (sym->st_shndx == SHN_UNDEF)
1498 return 'U';
1499 if (sym->st_shndx == SHN_ABS)
1500 return 'a';
1501 if (sym->st_shndx >= SHN_LORESERVE)
1502 return '?';
1503 if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
1504 return 't';
1505 if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
1506 && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
1507 if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
1508 return 'r';
1509 else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
1510 return 'g';
1511 else
1512 return 'd';
1513 }
1514 if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
1515 if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
1516 return 's';
1517 else
1518 return 'b';
1519 }
1520 if (strncmp(secstrings + sechdrs[sym->st_shndx].sh_name,
1521 ".debug", strlen(".debug")) == 0)
1522 return 'n';
1523 return '?';
1524 }
1525
1526 static void add_kallsyms(struct module *mod,
1527 Elf_Shdr *sechdrs,
1528 unsigned int symindex,
1529 unsigned int strindex,
1530 const char *secstrings)
1531 {
1532 unsigned int i;
1533
1534 mod->symtab = (void *)sechdrs[symindex].sh_addr;
1535 mod->num_symtab = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
1536 mod->strtab = (void *)sechdrs[strindex].sh_addr;
1537
1538 /* Set types up while we still have access to sections. */
1539 for (i = 0; i < mod->num_symtab; i++)
1540 mod->symtab[i].st_info
1541 = elf_type(&mod->symtab[i], sechdrs, secstrings, mod);
1542 }
1543 #else
1544 static inline void add_kallsyms(struct module *mod,
1545 Elf_Shdr *sechdrs,
1546 unsigned int symindex,
1547 unsigned int strindex,
1548 const char *secstrings)
1549 {
1550 }
1551 #endif /* CONFIG_KALLSYMS */
1552
1553 /* Allocate and load the module: note that size of section 0 is always
1554 zero, and we rely on this for optional sections. */
1555 static struct module *load_module(void __user *umod,
1556 unsigned long len,
1557 const char __user *uargs)
1558 {
1559 Elf_Ehdr *hdr;
1560 Elf_Shdr *sechdrs;
1561 char *secstrings, *args, *modmagic, *strtab = NULL;
1562 unsigned int i;
1563 unsigned int symindex = 0;
1564 unsigned int strindex = 0;
1565 unsigned int setupindex;
1566 unsigned int exindex;
1567 unsigned int exportindex;
1568 unsigned int modindex;
1569 unsigned int obsparmindex;
1570 unsigned int infoindex;
1571 unsigned int gplindex;
1572 unsigned int crcindex;
1573 unsigned int gplcrcindex;
1574 unsigned int versindex;
1575 unsigned int pcpuindex;
1576 unsigned int gplfutureindex;
1577 unsigned int gplfuturecrcindex;
1578 unsigned int unwindex = 0;
1579 unsigned int unusedindex;
1580 unsigned int unusedcrcindex;
1581 unsigned int unusedgplindex;
1582 unsigned int unusedgplcrcindex;
1583 struct module *mod;
1584 long err = 0;
1585 void *percpu = NULL, *ptr = NULL; /* Stops spurious gcc warning */
1586 struct exception_table_entry *extable;
1587 mm_segment_t old_fs;
1588
1589 DEBUGP("load_module: umod=%p, len=%lu, uargs=%p\n",
1590 umod, len, uargs);
1591 if (len < sizeof(*hdr))
1592 return ERR_PTR(-ENOEXEC);
1593
1594 /* Suck in entire file: we'll want most of it. */
1595 /* vmalloc barfs on "unusual" numbers. Check here */
1596 if (len > 64 * 1024 * 1024 || (hdr = vmalloc(len)) == NULL)
1597 return ERR_PTR(-ENOMEM);
1598 if (copy_from_user(hdr, umod, len) != 0) {
1599 err = -EFAULT;
1600 goto free_hdr;
1601 }
1602
1603 /* Sanity checks against insmoding binaries or wrong arch,
1604 weird elf version */
1605 if (memcmp(hdr->e_ident, ELFMAG, 4) != 0
1606 || hdr->e_type != ET_REL
1607 || !elf_check_arch(hdr)
1608 || hdr->e_shentsize != sizeof(*sechdrs)) {
1609 err = -ENOEXEC;
1610 goto free_hdr;
1611 }
1612
1613 if (len < hdr->e_shoff + hdr->e_shnum * sizeof(Elf_Shdr))
1614 goto truncated;
1615
1616 /* Convenience variables */
1617 sechdrs = (void *)hdr + hdr->e_shoff;
1618 secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
1619 sechdrs[0].sh_addr = 0;
1620
1621 for (i = 1; i < hdr->e_shnum; i++) {
1622 if (sechdrs[i].sh_type != SHT_NOBITS
1623 && len < sechdrs[i].sh_offset + sechdrs[i].sh_size)
1624 goto truncated;
1625
1626 /* Mark all sections sh_addr with their address in the
1627 temporary image. */
1628 sechdrs[i].sh_addr = (size_t)hdr + sechdrs[i].sh_offset;
1629
1630 /* Internal symbols and strings. */
1631 if (sechdrs[i].sh_type == SHT_SYMTAB) {
1632 symindex = i;
1633 strindex = sechdrs[i].sh_link;
1634 strtab = (char *)hdr + sechdrs[strindex].sh_offset;
1635 }
1636 #ifndef CONFIG_MODULE_UNLOAD
1637 /* Don't load .exit sections */
1638 if (strncmp(secstrings+sechdrs[i].sh_name, ".exit", 5) == 0)
1639 sechdrs[i].sh_flags &= ~(unsigned long)SHF_ALLOC;
1640 #endif
1641 }
1642
1643 modindex = find_sec(hdr, sechdrs, secstrings,
1644 ".gnu.linkonce.this_module");
1645 if (!modindex) {
1646 printk(KERN_WARNING "No module found in object\n");
1647 err = -ENOEXEC;
1648 goto free_hdr;
1649 }
1650 mod = (void *)sechdrs[modindex].sh_addr;
1651
1652 if (symindex == 0) {
1653 printk(KERN_WARNING "%s: module has no symbols (stripped?)\n",
1654 mod->name);
1655 err = -ENOEXEC;
1656 goto free_hdr;
1657 }
1658
1659 /* Optional sections */
1660 exportindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab");
1661 gplindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_gpl");
1662 gplfutureindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_gpl_future");
1663 unusedindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_unused");
1664 unusedgplindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_unused_gpl");
1665 crcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab");
1666 gplcrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_gpl");
1667 gplfuturecrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_gpl_future");
1668 unusedcrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_unused");
1669 unusedgplcrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_unused_gpl");
1670 setupindex = find_sec(hdr, sechdrs, secstrings, "__param");
1671 exindex = find_sec(hdr, sechdrs, secstrings, "__ex_table");
1672 obsparmindex = find_sec(hdr, sechdrs, secstrings, "__obsparm");
1673 versindex = find_sec(hdr, sechdrs, secstrings, "__versions");
1674 infoindex = find_sec(hdr, sechdrs, secstrings, ".modinfo");
1675 pcpuindex = find_pcpusec(hdr, sechdrs, secstrings);
1676 #ifdef ARCH_UNWIND_SECTION_NAME
1677 unwindex = find_sec(hdr, sechdrs, secstrings, ARCH_UNWIND_SECTION_NAME);
1678 #endif
1679
1680 /* Don't keep modinfo section */
1681 sechdrs[infoindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
1682 #ifdef CONFIG_KALLSYMS
1683 /* Keep symbol and string tables for decoding later. */
1684 sechdrs[symindex].sh_flags |= SHF_ALLOC;
1685 sechdrs[strindex].sh_flags |= SHF_ALLOC;
1686 #endif
1687 if (unwindex)
1688 sechdrs[unwindex].sh_flags |= SHF_ALLOC;
1689
1690 /* Check module struct version now, before we try to use module. */
1691 if (!check_modstruct_version(sechdrs, versindex, mod)) {
1692 err = -ENOEXEC;
1693 goto free_hdr;
1694 }
1695
1696 modmagic = get_modinfo(sechdrs, infoindex, "vermagic");
1697 /* This is allowed: modprobe --force will invalidate it. */
1698 if (!modmagic) {
1699 add_taint_module(mod, TAINT_FORCED_MODULE);
1700 printk(KERN_WARNING "%s: no version magic, tainting kernel.\n",
1701 mod->name);
1702 } else if (!same_magic(modmagic, vermagic)) {
1703 printk(KERN_ERR "%s: version magic '%s' should be '%s'\n",
1704 mod->name, modmagic, vermagic);
1705 err = -ENOEXEC;
1706 goto free_hdr;
1707 }
1708
1709 /* Now copy in args */
1710 args = strndup_user(uargs, ~0UL >> 1);
1711 if (IS_ERR(args)) {
1712 err = PTR_ERR(args);
1713 goto free_hdr;
1714 }
1715
1716 if (find_module(mod->name)) {
1717 err = -EEXIST;
1718 goto free_mod;
1719 }
1720
1721 mod->state = MODULE_STATE_COMING;
1722
1723 /* Allow arches to frob section contents and sizes. */
1724 err = module_frob_arch_sections(hdr, sechdrs, secstrings, mod);
1725 if (err < 0)
1726 goto free_mod;
1727
1728 if (pcpuindex) {
1729 /* We have a special allocation for this section. */
1730 percpu = percpu_modalloc(sechdrs[pcpuindex].sh_size,
1731 sechdrs[pcpuindex].sh_addralign,
1732 mod->name);
1733 if (!percpu) {
1734 err = -ENOMEM;
1735 goto free_mod;
1736 }
1737 sechdrs[pcpuindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
1738 mod->percpu = percpu;
1739 }
1740
1741 /* Determine total sizes, and put offsets in sh_entsize. For now
1742 this is done generically; there doesn't appear to be any
1743 special cases for the architectures. */
1744 layout_sections(mod, hdr, sechdrs, secstrings);
1745
1746 /* Do the allocs. */
1747 ptr = module_alloc(mod->core_size);
1748 if (!ptr) {
1749 err = -ENOMEM;
1750 goto free_percpu;
1751 }
1752 memset(ptr, 0, mod->core_size);
1753 mod->module_core = ptr;
1754
1755 ptr = module_alloc(mod->init_size);
1756 if (!ptr && mod->init_size) {
1757 err = -ENOMEM;
1758 goto free_core;
1759 }
1760 memset(ptr, 0, mod->init_size);
1761 mod->module_init = ptr;
1762
1763 /* Transfer each section which specifies SHF_ALLOC */
1764 DEBUGP("final section addresses:\n");
1765 for (i = 0; i < hdr->e_shnum; i++) {
1766 void *dest;
1767
1768 if (!(sechdrs[i].sh_flags & SHF_ALLOC))
1769 continue;
1770
1771 if (sechdrs[i].sh_entsize & INIT_OFFSET_MASK)
1772 dest = mod->module_init
1773 + (sechdrs[i].sh_entsize & ~INIT_OFFSET_MASK);
1774 else
1775 dest = mod->module_core + sechdrs[i].sh_entsize;
1776
1777 if (sechdrs[i].sh_type != SHT_NOBITS)
1778 memcpy(dest, (void *)sechdrs[i].sh_addr,
1779 sechdrs[i].sh_size);
1780 /* Update sh_addr to point to copy in image. */
1781 sechdrs[i].sh_addr = (unsigned long)dest;
1782 DEBUGP("\t0x%lx %s\n", sechdrs[i].sh_addr, secstrings + sechdrs[i].sh_name);
1783 }
1784 /* Module has been moved. */
1785 mod = (void *)sechdrs[modindex].sh_addr;
1786
1787 /* Now we've moved module, initialize linked lists, etc. */
1788 module_unload_init(mod);
1789
1790 /* Initialize kobject, so we can reference it. */
1791 if (mod_sysfs_init(mod) != 0)
1792 goto cleanup;
1793
1794 /* Set up license info based on the info section */
1795 set_license(mod, get_modinfo(sechdrs, infoindex, "license"));
1796
1797 if (strcmp(mod->name, "ndiswrapper") == 0)
1798 add_taint(TAINT_PROPRIETARY_MODULE);
1799 if (strcmp(mod->name, "driverloader") == 0)
1800 add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
1801
1802 /* Set up MODINFO_ATTR fields */
1803 setup_modinfo(mod, sechdrs, infoindex);
1804
1805 /* Fix up syms, so that st_value is a pointer to location. */
1806 err = simplify_symbols(sechdrs, symindex, strtab, versindex, pcpuindex,
1807 mod);
1808 if (err < 0)
1809 goto cleanup;
1810
1811 /* Set up EXPORTed & EXPORT_GPLed symbols (section 0 is 0 length) */
1812 mod->num_syms = sechdrs[exportindex].sh_size / sizeof(*mod->syms);
1813 mod->syms = (void *)sechdrs[exportindex].sh_addr;
1814 if (crcindex)
1815 mod->crcs = (void *)sechdrs[crcindex].sh_addr;
1816 mod->num_gpl_syms = sechdrs[gplindex].sh_size / sizeof(*mod->gpl_syms);
1817 mod->gpl_syms = (void *)sechdrs[gplindex].sh_addr;
1818 if (gplcrcindex)
1819 mod->gpl_crcs = (void *)sechdrs[gplcrcindex].sh_addr;
1820 mod->num_gpl_future_syms = sechdrs[gplfutureindex].sh_size /
1821 sizeof(*mod->gpl_future_syms);
1822 mod->num_unused_syms = sechdrs[unusedindex].sh_size /
1823 sizeof(*mod->unused_syms);
1824 mod->num_unused_gpl_syms = sechdrs[unusedgplindex].sh_size /
1825 sizeof(*mod->unused_gpl_syms);
1826 mod->gpl_future_syms = (void *)sechdrs[gplfutureindex].sh_addr;
1827 if (gplfuturecrcindex)
1828 mod->gpl_future_crcs = (void *)sechdrs[gplfuturecrcindex].sh_addr;
1829
1830 mod->unused_syms = (void *)sechdrs[unusedindex].sh_addr;
1831 if (unusedcrcindex)
1832 mod->unused_crcs = (void *)sechdrs[unusedcrcindex].sh_addr;
1833 mod->unused_gpl_syms = (void *)sechdrs[unusedgplindex].sh_addr;
1834 if (unusedgplcrcindex)
1835 mod->unused_crcs = (void *)sechdrs[unusedgplcrcindex].sh_addr;
1836
1837 #ifdef CONFIG_MODVERSIONS
1838 if ((mod->num_syms && !crcindex) ||
1839 (mod->num_gpl_syms && !gplcrcindex) ||
1840 (mod->num_gpl_future_syms && !gplfuturecrcindex) ||
1841 (mod->num_unused_syms && !unusedcrcindex) ||
1842 (mod->num_unused_gpl_syms && !unusedgplcrcindex)) {
1843 printk(KERN_WARNING "%s: No versions for exported symbols."
1844 " Tainting kernel.\n", mod->name);
1845 add_taint_module(mod, TAINT_FORCED_MODULE);
1846 }
1847 #endif
1848
1849 /* Now do relocations. */
1850 for (i = 1; i < hdr->e_shnum; i++) {
1851 const char *strtab = (char *)sechdrs[strindex].sh_addr;
1852 unsigned int info = sechdrs[i].sh_info;
1853
1854 /* Not a valid relocation section? */
1855 if (info >= hdr->e_shnum)
1856 continue;
1857
1858 /* Don't bother with non-allocated sections */
1859 if (!(sechdrs[info].sh_flags & SHF_ALLOC))
1860 continue;
1861
1862 if (sechdrs[i].sh_type == SHT_REL)
1863 err = apply_relocate(sechdrs, strtab, symindex, i,mod);
1864 else if (sechdrs[i].sh_type == SHT_RELA)
1865 err = apply_relocate_add(sechdrs, strtab, symindex, i,
1866 mod);
1867 if (err < 0)
1868 goto cleanup;
1869 }
1870
1871 /* Find duplicate symbols */
1872 err = verify_export_symbols(mod);
1873
1874 if (err < 0)
1875 goto cleanup;
1876
1877 /* Set up and sort exception table */
1878 mod->num_exentries = sechdrs[exindex].sh_size / sizeof(*mod->extable);
1879 mod->extable = extable = (void *)sechdrs[exindex].sh_addr;
1880 sort_extable(extable, extable + mod->num_exentries);
1881
1882 /* Finally, copy percpu area over. */
1883 percpu_modcopy(mod->percpu, (void *)sechdrs[pcpuindex].sh_addr,
1884 sechdrs[pcpuindex].sh_size);
1885
1886 add_kallsyms(mod, sechdrs, symindex, strindex, secstrings);
1887
1888 err = module_finalize(hdr, sechdrs, mod);
1889 if (err < 0)
1890 goto cleanup;
1891
1892 /* flush the icache in correct context */
1893 old_fs = get_fs();
1894 set_fs(KERNEL_DS);
1895
1896 /*
1897 * Flush the instruction cache, since we've played with text.
1898 * Do it before processing of module parameters, so the module
1899 * can provide parameter accessor functions of its own.
1900 */
1901 if (mod->module_init)
1902 flush_icache_range((unsigned long)mod->module_init,
1903 (unsigned long)mod->module_init
1904 + mod->init_size);
1905 flush_icache_range((unsigned long)mod->module_core,
1906 (unsigned long)mod->module_core + mod->core_size);
1907
1908 set_fs(old_fs);
1909
1910 mod->args = args;
1911 if (obsparmindex)
1912 printk(KERN_WARNING "%s: Ignoring obsolete parameters\n",
1913 mod->name);
1914
1915 /* Size of section 0 is 0, so this works well if no params */
1916 err = parse_args(mod->name, mod->args,
1917 (struct kernel_param *)
1918 sechdrs[setupindex].sh_addr,
1919 sechdrs[setupindex].sh_size
1920 / sizeof(struct kernel_param),
1921 NULL);
1922 if (err < 0)
1923 goto arch_cleanup;
1924
1925 err = mod_sysfs_setup(mod,
1926 (struct kernel_param *)
1927 sechdrs[setupindex].sh_addr,
1928 sechdrs[setupindex].sh_size
1929 / sizeof(struct kernel_param));
1930 if (err < 0)
1931 goto arch_cleanup;
1932 add_sect_attrs(mod, hdr->e_shnum, secstrings, sechdrs);
1933
1934 /* Size of section 0 is 0, so this works well if no unwind info. */
1935 mod->unwind_info = unwind_add_table(mod,
1936 (void *)sechdrs[unwindex].sh_addr,
1937 sechdrs[unwindex].sh_size);
1938
1939 /* Get rid of temporary copy */
1940 vfree(hdr);
1941
1942 /* Done! */
1943 return mod;
1944
1945 arch_cleanup:
1946 module_arch_cleanup(mod);
1947 cleanup:
1948 module_unload_free(mod);
1949 module_free(mod, mod->module_init);
1950 free_core:
1951 module_free(mod, mod->module_core);
1952 free_percpu:
1953 if (percpu)
1954 percpu_modfree(percpu);
1955 free_mod:
1956 kfree(args);
1957 free_hdr:
1958 vfree(hdr);
1959 return ERR_PTR(err);
1960
1961 truncated:
1962 printk(KERN_ERR "Module len %lu truncated\n", len);
1963 err = -ENOEXEC;
1964 goto free_hdr;
1965 }
1966
1967 /*
1968 * link the module with the whole machine is stopped with interrupts off
1969 * - this defends against kallsyms not taking locks
1970 */
1971 static int __link_module(void *_mod)
1972 {
1973 struct module *mod = _mod;
1974 list_add(&mod->list, &modules);
1975 return 0;
1976 }
1977
1978 /* This is where the real work happens */
1979 asmlinkage long
1980 sys_init_module(void __user *umod,
1981 unsigned long len,
1982 const char __user *uargs)
1983 {
1984 struct module *mod;
1985 int ret = 0;
1986
1987 /* Must have permission */
1988 if (!capable(CAP_SYS_MODULE))
1989 return -EPERM;
1990
1991 /* Only one module load at a time, please */
1992 if (mutex_lock_interruptible(&module_mutex) != 0)
1993 return -EINTR;
1994
1995 /* Do all the hard work */
1996 mod = load_module(umod, len, uargs);
1997 if (IS_ERR(mod)) {
1998 mutex_unlock(&module_mutex);
1999 return PTR_ERR(mod);
2000 }
2001
2002 /* Now sew it into the lists. They won't access us, since
2003 strong_try_module_get() will fail. */
2004 stop_machine_run(__link_module, mod, NR_CPUS);
2005
2006 /* Drop lock so they can recurse */
2007 mutex_unlock(&module_mutex);
2008
2009 blocking_notifier_call_chain(&module_notify_list,
2010 MODULE_STATE_COMING, mod);
2011
2012 /* Start the module */
2013 if (mod->init != NULL)
2014 ret = mod->init();
2015 if (ret < 0) {
2016 /* Init routine failed: abort. Try to protect us from
2017 buggy refcounters. */
2018 mod->state = MODULE_STATE_GOING;
2019 synchronize_sched();
2020 if (mod->unsafe)
2021 printk(KERN_ERR "%s: module is now stuck!\n",
2022 mod->name);
2023 else {
2024 module_put(mod);
2025 mutex_lock(&module_mutex);
2026 free_module(mod);
2027 mutex_unlock(&module_mutex);
2028 }
2029 return ret;
2030 }
2031
2032 /* Now it's a first class citizen! */
2033 mutex_lock(&module_mutex);
2034 mod->state = MODULE_STATE_LIVE;
2035 /* Drop initial reference. */
2036 module_put(mod);
2037 unwind_remove_table(mod->unwind_info, 1);
2038 module_free(mod, mod->module_init);
2039 mod->module_init = NULL;
2040 mod->init_size = 0;
2041 mod->init_text_size = 0;
2042 mutex_unlock(&module_mutex);
2043
2044 return 0;
2045 }
2046
2047 static inline int within(unsigned long addr, void *start, unsigned long size)
2048 {
2049 return ((void *)addr >= start && (void *)addr < start + size);
2050 }
2051
2052 #ifdef CONFIG_KALLSYMS
2053 /*
2054 * This ignores the intensely annoying "mapping symbols" found
2055 * in ARM ELF files: $a, $t and $d.
2056 */
2057 static inline int is_arm_mapping_symbol(const char *str)
2058 {
2059 return str[0] == '$' && strchr("atd", str[1])
2060 && (str[2] == '\0' || str[2] == '.');
2061 }
2062
2063 static const char *get_ksymbol(struct module *mod,
2064 unsigned long addr,
2065 unsigned long *size,
2066 unsigned long *offset)
2067 {
2068 unsigned int i, best = 0;
2069 unsigned long nextval;
2070
2071 /* At worse, next value is at end of module */
2072 if (within(addr, mod->module_init, mod->init_size))
2073 nextval = (unsigned long)mod->module_init+mod->init_text_size;
2074 else
2075 nextval = (unsigned long)mod->module_core+mod->core_text_size;
2076
2077 /* Scan for closest preceeding symbol, and next symbol. (ELF
2078 starts real symbols at 1). */
2079 for (i = 1; i < mod->num_symtab; i++) {
2080 if (mod->symtab[i].st_shndx == SHN_UNDEF)
2081 continue;
2082
2083 /* We ignore unnamed symbols: they're uninformative
2084 * and inserted at a whim. */
2085 if (mod->symtab[i].st_value <= addr
2086 && mod->symtab[i].st_value > mod->symtab[best].st_value
2087 && *(mod->strtab + mod->symtab[i].st_name) != '\0'
2088 && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
2089 best = i;
2090 if (mod->symtab[i].st_value > addr
2091 && mod->symtab[i].st_value < nextval
2092 && *(mod->strtab + mod->symtab[i].st_name) != '\0'
2093 && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
2094 nextval = mod->symtab[i].st_value;
2095 }
2096
2097 if (!best)
2098 return NULL;
2099
2100 *size = nextval - mod->symtab[best].st_value;
2101 *offset = addr - mod->symtab[best].st_value;
2102 return mod->strtab + mod->symtab[best].st_name;
2103 }
2104
2105 /* For kallsyms to ask for address resolution. NULL means not found.
2106 We don't lock, as this is used for oops resolution and races are a
2107 lesser concern. */
2108 const char *module_address_lookup(unsigned long addr,
2109 unsigned long *size,
2110 unsigned long *offset,
2111 char **modname)
2112 {
2113 struct module *mod;
2114
2115 list_for_each_entry(mod, &modules, list) {
2116 if (within(addr, mod->module_init, mod->init_size)
2117 || within(addr, mod->module_core, mod->core_size)) {
2118 if (modname)
2119 *modname = mod->name;
2120 return get_ksymbol(mod, addr, size, offset);
2121 }
2122 }
2123 return NULL;
2124 }
2125
2126 struct module *module_get_kallsym(unsigned int symnum, unsigned long *value,
2127 char *type, char *name, size_t namelen)
2128 {
2129 struct module *mod;
2130
2131 mutex_lock(&module_mutex);
2132 list_for_each_entry(mod, &modules, list) {
2133 if (symnum < mod->num_symtab) {
2134 *value = mod->symtab[symnum].st_value;
2135 *type = mod->symtab[symnum].st_info;
2136 strlcpy(name, mod->strtab + mod->symtab[symnum].st_name,
2137 namelen);
2138 mutex_unlock(&module_mutex);
2139 return mod;
2140 }
2141 symnum -= mod->num_symtab;
2142 }
2143 mutex_unlock(&module_mutex);
2144 return NULL;
2145 }
2146
2147 static unsigned long mod_find_symname(struct module *mod, const char *name)
2148 {
2149 unsigned int i;
2150
2151 for (i = 0; i < mod->num_symtab; i++)
2152 if (strcmp(name, mod->strtab+mod->symtab[i].st_name) == 0 &&
2153 mod->symtab[i].st_info != 'U')
2154 return mod->symtab[i].st_value;
2155 return 0;
2156 }
2157
2158 /* Look for this name: can be of form module:name. */
2159 unsigned long module_kallsyms_lookup_name(const char *name)
2160 {
2161 struct module *mod;
2162 char *colon;
2163 unsigned long ret = 0;
2164
2165 /* Don't lock: we're in enough trouble already. */
2166 if ((colon = strchr(name, ':')) != NULL) {
2167 *colon = '\0';
2168 if ((mod = find_module(name)) != NULL)
2169 ret = mod_find_symname(mod, colon+1);
2170 *colon = ':';
2171 } else {
2172 list_for_each_entry(mod, &modules, list)
2173 if ((ret = mod_find_symname(mod, name)) != 0)
2174 break;
2175 }
2176 return ret;
2177 }
2178 #endif /* CONFIG_KALLSYMS */
2179
2180 /* Called by the /proc file system to return a list of modules. */
2181 static void *m_start(struct seq_file *m, loff_t *pos)
2182 {
2183 struct list_head *i;
2184 loff_t n = 0;
2185
2186 mutex_lock(&module_mutex);
2187 list_for_each(i, &modules) {
2188 if (n++ == *pos)
2189 break;
2190 }
2191 if (i == &modules)
2192 return NULL;
2193 return i;
2194 }
2195
2196 static void *m_next(struct seq_file *m, void *p, loff_t *pos)
2197 {
2198 struct list_head *i = p;
2199 (*pos)++;
2200 if (i->next == &modules)
2201 return NULL;
2202 return i->next;
2203 }
2204
2205 static void m_stop(struct seq_file *m, void *p)
2206 {
2207 mutex_unlock(&module_mutex);
2208 }
2209
2210 static char *taint_flags(unsigned int taints, char *buf)
2211 {
2212 int bx = 0;
2213
2214 if (taints) {
2215 buf[bx++] = '(';
2216 if (taints & TAINT_PROPRIETARY_MODULE)
2217 buf[bx++] = 'P';
2218 if (taints & TAINT_FORCED_MODULE)
2219 buf[bx++] = 'F';
2220 /*
2221 * TAINT_FORCED_RMMOD: could be added.
2222 * TAINT_UNSAFE_SMP, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't
2223 * apply to modules.
2224 */
2225 buf[bx++] = ')';
2226 }
2227 buf[bx] = '\0';
2228
2229 return buf;
2230 }
2231
2232 static int m_show(struct seq_file *m, void *p)
2233 {
2234 struct module *mod = list_entry(p, struct module, list);
2235 char buf[8];
2236
2237 seq_printf(m, "%s %lu",
2238 mod->name, mod->init_size + mod->core_size);
2239 print_unload_info(m, mod);
2240
2241 /* Informative for users. */
2242 seq_printf(m, " %s",
2243 mod->state == MODULE_STATE_GOING ? "Unloading":
2244 mod->state == MODULE_STATE_COMING ? "Loading":
2245 "Live");
2246 /* Used by oprofile and other similar tools. */
2247 seq_printf(m, " 0x%p", mod->module_core);
2248
2249 /* Taints info */
2250 if (mod->taints)
2251 seq_printf(m, " %s", taint_flags(mod->taints, buf));
2252
2253 seq_printf(m, "\n");
2254 return 0;
2255 }
2256
2257 /* Format: modulename size refcount deps address
2258
2259 Where refcount is a number or -, and deps is a comma-separated list
2260 of depends or -.
2261 */
2262 const struct seq_operations modules_op = {
2263 .start = m_start,
2264 .next = m_next,
2265 .stop = m_stop,
2266 .show = m_show
2267 };
2268
2269 /* Given an address, look for it in the module exception tables. */
2270 const struct exception_table_entry *search_module_extables(unsigned long addr)
2271 {
2272 unsigned long flags;
2273 const struct exception_table_entry *e = NULL;
2274 struct module *mod;
2275
2276 spin_lock_irqsave(&modlist_lock, flags);
2277 list_for_each_entry(mod, &modules, list) {
2278 if (mod->num_exentries == 0)
2279 continue;
2280
2281 e = search_extable(mod->extable,
2282 mod->extable + mod->num_exentries - 1,
2283 addr);
2284 if (e)
2285 break;
2286 }
2287 spin_unlock_irqrestore(&modlist_lock, flags);
2288
2289 /* Now, if we found one, we are running inside it now, hence
2290 we cannot unload the module, hence no refcnt needed. */
2291 return e;
2292 }
2293
2294 /*
2295 * Is this a valid module address?
2296 */
2297 int is_module_address(unsigned long addr)
2298 {
2299 unsigned long flags;
2300 struct module *mod;
2301
2302 spin_lock_irqsave(&modlist_lock, flags);
2303
2304 list_for_each_entry(mod, &modules, list) {
2305 if (within(addr, mod->module_core, mod->core_size)) {
2306 spin_unlock_irqrestore(&modlist_lock, flags);
2307 return 1;
2308 }
2309 }
2310
2311 spin_unlock_irqrestore(&modlist_lock, flags);
2312
2313 return 0;
2314 }
2315
2316
2317 /* Is this a valid kernel address? We don't grab the lock: we are oopsing. */
2318 struct module *__module_text_address(unsigned long addr)
2319 {
2320 struct module *mod;
2321
2322 list_for_each_entry(mod, &modules, list)
2323 if (within(addr, mod->module_init, mod->init_text_size)
2324 || within(addr, mod->module_core, mod->core_text_size))
2325 return mod;
2326 return NULL;
2327 }
2328
2329 struct module *module_text_address(unsigned long addr)
2330 {
2331 struct module *mod;
2332 unsigned long flags;
2333
2334 spin_lock_irqsave(&modlist_lock, flags);
2335 mod = __module_text_address(addr);
2336 spin_unlock_irqrestore(&modlist_lock, flags);
2337
2338 return mod;
2339 }
2340
2341 /* Don't grab lock, we're oopsing. */
2342 void print_modules(void)
2343 {
2344 struct module *mod;
2345 char buf[8];
2346
2347 printk("Modules linked in:");
2348 list_for_each_entry(mod, &modules, list)
2349 printk(" %s%s", mod->name, taint_flags(mod->taints, buf));
2350 printk("\n");
2351 }
2352
2353 #ifdef CONFIG_SYSFS
2354 static char *make_driver_name(struct device_driver *drv)
2355 {
2356 char *driver_name;
2357
2358 driver_name = kmalloc(strlen(drv->name) + strlen(drv->bus->name) + 2,
2359 GFP_KERNEL);
2360 if (!driver_name)
2361 return NULL;
2362
2363 sprintf(driver_name, "%s:%s", drv->bus->name, drv->name);
2364 return driver_name;
2365 }
2366
2367 static void module_create_drivers_dir(struct module_kobject *mk)
2368 {
2369 if (!mk || mk->drivers_dir)
2370 return;
2371
2372 mk->drivers_dir = kobject_add_dir(&mk->kobj, "drivers");
2373 }
2374
2375 void module_add_driver(struct module *mod, struct device_driver *drv)
2376 {
2377 char *driver_name;
2378 int no_warn;
2379 struct module_kobject *mk = NULL;
2380
2381 if (!drv)
2382 return;
2383
2384 if (mod)
2385 mk = &mod->mkobj;
2386 else if (drv->mod_name) {
2387 struct kobject *mkobj;
2388
2389 /* Lookup built-in module entry in /sys/modules */
2390 mkobj = kset_find_obj(&module_subsys, drv->mod_name);
2391 if (mkobj) {
2392 mk = container_of(mkobj, struct module_kobject, kobj);
2393 /* remember our module structure */
2394 drv->mkobj = mk;
2395 /* kset_find_obj took a reference */
2396 kobject_put(mkobj);
2397 }
2398 }
2399
2400 if (!mk)
2401 return;
2402
2403 /* Don't check return codes; these calls are idempotent */
2404 no_warn = sysfs_create_link(&drv->kobj, &mk->kobj, "module");
2405 driver_name = make_driver_name(drv);
2406 if (driver_name) {
2407 module_create_drivers_dir(mk);
2408 no_warn = sysfs_create_link(mk->drivers_dir, &drv->kobj,
2409 driver_name);
2410 kfree(driver_name);
2411 }
2412 }
2413 EXPORT_SYMBOL(module_add_driver);
2414
2415 void module_remove_driver(struct device_driver *drv)
2416 {
2417 struct module_kobject *mk = NULL;
2418 char *driver_name;
2419
2420 if (!drv)
2421 return;
2422
2423 sysfs_remove_link(&drv->kobj, "module");
2424
2425 if (drv->owner)
2426 mk = &drv->owner->mkobj;
2427 else if (drv->mkobj)
2428 mk = drv->mkobj;
2429 if (mk && mk->drivers_dir) {
2430 driver_name = make_driver_name(drv);
2431 if (driver_name) {
2432 sysfs_remove_link(mk->drivers_dir, driver_name);
2433 kfree(driver_name);
2434 }
2435 }
2436 }
2437 EXPORT_SYMBOL(module_remove_driver);
2438 #endif
2439
2440 #ifdef CONFIG_MODVERSIONS
2441 /* Generate the signature for struct module here, too, for modversions. */
2442 void struct_module(struct module *mod) { return; }
2443 EXPORT_SYMBOL(struct_module);
2444 #endif
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