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[linux-2.6/openmoko-kernel/knife-kernel.git] / kernel / module.c
blob7a1a4d3558d5ccc33d994ce7c2ac4e9176841a62
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/kallsyms.h>
23 #include <linux/kernel.h>
24 #include <linux/slab.h>
25 #include <linux/vmalloc.h>
26 #include <linux/elf.h>
27 #include <linux/seq_file.h>
28 #include <linux/syscalls.h>
29 #include <linux/fcntl.h>
30 #include <linux/rcupdate.h>
31 #include <linux/capability.h>
32 #include <linux/cpu.h>
33 #include <linux/moduleparam.h>
34 #include <linux/errno.h>
35 #include <linux/err.h>
36 #include <linux/vermagic.h>
37 #include <linux/notifier.h>
38 #include <linux/sched.h>
39 #include <linux/stop_machine.h>
40 #include <linux/device.h>
41 #include <linux/string.h>
42 #include <linux/mutex.h>
43 #include <linux/unwind.h>
44 #include <asm/uaccess.h>
45 #include <asm/semaphore.h>
46 #include <asm/cacheflush.h>
47 #include <linux/license.h>
48
49 extern int module_sysfs_initialized;
50
51 #if 0
52 #define DEBUGP printk
53 #else
54 #define DEBUGP(fmt , a...)
55 #endif
56
57 #ifndef ARCH_SHF_SMALL
58 #define ARCH_SHF_SMALL 0
59 #endif
60
61 /* If this is set, the section belongs in the init part of the module */
62 #define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
63
64 /* Protects module list */
65 static DEFINE_SPINLOCK(modlist_lock);
66
67 /* List of modules, protected by module_mutex AND modlist_lock */
68 static DEFINE_MUTEX(module_mutex);
69 static LIST_HEAD(modules);
70
71 static BLOCKING_NOTIFIER_HEAD(module_notify_list);
72
73 int register_module_notifier(struct notifier_block * nb)
74 {
75 return blocking_notifier_chain_register(&module_notify_list, nb);
76 }
77 EXPORT_SYMBOL(register_module_notifier);
78
79 int unregister_module_notifier(struct notifier_block * nb)
80 {
81 return blocking_notifier_chain_unregister(&module_notify_list, nb);
82 }
83 EXPORT_SYMBOL(unregister_module_notifier);
84
85 /* We require a truly strong try_module_get() */
86 static inline int strong_try_module_get(struct module *mod)
87 {
88 if (mod && mod->state == MODULE_STATE_COMING)
89 return 0;
90 return try_module_get(mod);
91 }
92
93 static inline void add_taint_module(struct module *mod, unsigned flag)
94 {
95 add_taint(flag);
96 mod->taints |= flag;
97 }
98
99 /*
100 * A thread that wants to hold a reference to a module only while it
101 * is running can call this to safely exit. nfsd and lockd use this.
102 */
103 void __module_put_and_exit(struct module *mod, long code)
104 {
105 module_put(mod);
106 do_exit(code);
107 }
108 EXPORT_SYMBOL(__module_put_and_exit);
109
110 /* Find a module section: 0 means not found. */
111 static unsigned int find_sec(Elf_Ehdr *hdr,
112 Elf_Shdr *sechdrs,
113 const char *secstrings,
114 const char *name)
115 {
116 unsigned int i;
117
118 for (i = 1; i < hdr->e_shnum; i++)
119 /* Alloc bit cleared means "ignore it." */
120 if ((sechdrs[i].sh_flags & SHF_ALLOC)
121 && strcmp(secstrings+sechdrs[i].sh_name, name) == 0)
122 return i;
123 return 0;
124 }
125
126 /* Provided by the linker */
127 extern const struct kernel_symbol __start___ksymtab[];
128 extern const struct kernel_symbol __stop___ksymtab[];
129 extern const struct kernel_symbol __start___ksymtab_gpl[];
130 extern const struct kernel_symbol __stop___ksymtab_gpl[];
131 extern const struct kernel_symbol __start___ksymtab_gpl_future[];
132 extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
133 extern const struct kernel_symbol __start___ksymtab_unused[];
134 extern const struct kernel_symbol __stop___ksymtab_unused[];
135 extern const struct kernel_symbol __start___ksymtab_unused_gpl[];
136 extern const struct kernel_symbol __stop___ksymtab_unused_gpl[];
137 extern const struct kernel_symbol __start___ksymtab_gpl_future[];
138 extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
139 extern const unsigned long __start___kcrctab[];
140 extern const unsigned long __start___kcrctab_gpl[];
141 extern const unsigned long __start___kcrctab_gpl_future[];
142 extern const unsigned long __start___kcrctab_unused[];
143 extern const unsigned long __start___kcrctab_unused_gpl[];
144
145 #ifndef CONFIG_MODVERSIONS
146 #define symversion(base, idx) NULL
147 #else
148 #define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
149 #endif
150
151 /* lookup symbol in given range of kernel_symbols */
152 static const struct kernel_symbol *lookup_symbol(const char *name,
153 const struct kernel_symbol *start,
154 const struct kernel_symbol *stop)
155 {
156 const struct kernel_symbol *ks = start;
157 for (; ks < stop; ks++)
158 if (strcmp(ks->name, name) == 0)
159 return ks;
160 return NULL;
161 }
162
163 static void printk_unused_warning(const char *name)
164 {
165 printk(KERN_WARNING "Symbol %s is marked as UNUSED, "
166 "however this module is using it.\n", name);
167 printk(KERN_WARNING "This symbol will go away in the future.\n");
168 printk(KERN_WARNING "Please evalute if this is the right api to use, "
169 "and if it really is, submit a report the linux kernel "
170 "mailinglist together with submitting your code for "
171 "inclusion.\n");
172 }
173
174 /* Find a symbol, return value, crc and module which owns it */
175 static unsigned long __find_symbol(const char *name,
176 struct module **owner,
177 const unsigned long **crc,
178 int gplok)
179 {
180 struct module *mod;
181 const struct kernel_symbol *ks;
182
183 /* Core kernel first. */
184 *owner = NULL;
185 ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
186 if (ks) {
187 *crc = symversion(__start___kcrctab, (ks - __start___ksymtab));
188 return ks->value;
189 }
190 if (gplok) {
191 ks = lookup_symbol(name, __start___ksymtab_gpl,
192 __stop___ksymtab_gpl);
193 if (ks) {
194 *crc = symversion(__start___kcrctab_gpl,
195 (ks - __start___ksymtab_gpl));
196 return ks->value;
197 }
198 }
199 ks = lookup_symbol(name, __start___ksymtab_gpl_future,
200 __stop___ksymtab_gpl_future);
201 if (ks) {
202 if (!gplok) {
203 printk(KERN_WARNING "Symbol %s is being used "
204 "by a non-GPL module, which will not "
205 "be allowed in the future\n", name);
206 printk(KERN_WARNING "Please see the file "
207 "Documentation/feature-removal-schedule.txt "
208 "in the kernel source tree for more "
209 "details.\n");
210 }
211 *crc = symversion(__start___kcrctab_gpl_future,
212 (ks - __start___ksymtab_gpl_future));
213 return ks->value;
214 }
215
216 ks = lookup_symbol(name, __start___ksymtab_unused,
217 __stop___ksymtab_unused);
218 if (ks) {
219 printk_unused_warning(name);
220 *crc = symversion(__start___kcrctab_unused,
221 (ks - __start___ksymtab_unused));
222 return ks->value;
223 }
224
225 if (gplok)
226 ks = lookup_symbol(name, __start___ksymtab_unused_gpl,
227 __stop___ksymtab_unused_gpl);
228 if (ks) {
229 printk_unused_warning(name);
230 *crc = symversion(__start___kcrctab_unused_gpl,
231 (ks - __start___ksymtab_unused_gpl));
232 return ks->value;
233 }
234
235 /* Now try modules. */
236 list_for_each_entry(mod, &modules, list) {
237 *owner = mod;
238 ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
239 if (ks) {
240 *crc = symversion(mod->crcs, (ks - mod->syms));
241 return ks->value;
242 }
243
244 if (gplok) {
245 ks = lookup_symbol(name, mod->gpl_syms,
246 mod->gpl_syms + mod->num_gpl_syms);
247 if (ks) {
248 *crc = symversion(mod->gpl_crcs,
249 (ks - mod->gpl_syms));
250 return ks->value;
251 }
252 }
253 ks = lookup_symbol(name, mod->unused_syms, mod->unused_syms + mod->num_unused_syms);
254 if (ks) {
255 printk_unused_warning(name);
256 *crc = symversion(mod->unused_crcs, (ks - mod->unused_syms));
257 return ks->value;
258 }
259
260 if (gplok) {
261 ks = lookup_symbol(name, mod->unused_gpl_syms,
262 mod->unused_gpl_syms + mod->num_unused_gpl_syms);
263 if (ks) {
264 printk_unused_warning(name);
265 *crc = symversion(mod->unused_gpl_crcs,
266 (ks - mod->unused_gpl_syms));
267 return ks->value;
268 }
269 }
270 ks = lookup_symbol(name, mod->gpl_future_syms,
271 (mod->gpl_future_syms +
272 mod->num_gpl_future_syms));
273 if (ks) {
274 if (!gplok) {
275 printk(KERN_WARNING "Symbol %s is being used "
276 "by a non-GPL module, which will not "
277 "be allowed in the future\n", name);
278 printk(KERN_WARNING "Please see the file "
279 "Documentation/feature-removal-schedule.txt "
280 "in the kernel source tree for more "
281 "details.\n");
282 }
283 *crc = symversion(mod->gpl_future_crcs,
284 (ks - mod->gpl_future_syms));
285 return ks->value;
286 }
287 }
288 DEBUGP("Failed to find symbol %s\n", name);
289 return 0;
290 }
291
292 /* Search for module by name: must hold module_mutex. */
293 static struct module *find_module(const char *name)
294 {
295 struct module *mod;
296
297 list_for_each_entry(mod, &modules, list) {
298 if (strcmp(mod->name, name) == 0)
299 return mod;
300 }
301 return NULL;
302 }
303
304 #ifdef CONFIG_SMP
305 /* Number of blocks used and allocated. */
306 static unsigned int pcpu_num_used, pcpu_num_allocated;
307 /* Size of each block. -ve means used. */
308 static int *pcpu_size;
309
310 static int split_block(unsigned int i, unsigned short size)
311 {
312 /* Reallocation required? */
313 if (pcpu_num_used + 1 > pcpu_num_allocated) {
314 int *new;
315
316 new = krealloc(pcpu_size, sizeof(new[0])*pcpu_num_allocated*2,
317 GFP_KERNEL);
318 if (!new)
319 return 0;
320
321 pcpu_num_allocated *= 2;
322 pcpu_size = new;
323 }
324
325 /* Insert a new subblock */
326 memmove(&pcpu_size[i+1], &pcpu_size[i],
327 sizeof(pcpu_size[0]) * (pcpu_num_used - i));
328 pcpu_num_used++;
329
330 pcpu_size[i+1] -= size;
331 pcpu_size[i] = size;
332 return 1;
333 }
334
335 static inline unsigned int block_size(int val)
336 {
337 if (val < 0)
338 return -val;
339 return val;
340 }
341
342 /* Created by linker magic */
343 extern char __per_cpu_start[], __per_cpu_end[];
344
345 static void *percpu_modalloc(unsigned long size, unsigned long align,
346 const char *name)
347 {
348 unsigned long extra;
349 unsigned int i;
350 void *ptr;
351
352 if (align > PAGE_SIZE) {
353 printk(KERN_WARNING "%s: per-cpu alignment %li > %li\n",
354 name, align, PAGE_SIZE);
355 align = PAGE_SIZE;
356 }
357
358 ptr = __per_cpu_start;
359 for (i = 0; i < pcpu_num_used; ptr += block_size(pcpu_size[i]), i++) {
360 /* Extra for alignment requirement. */
361 extra = ALIGN((unsigned long)ptr, align) - (unsigned long)ptr;
362 BUG_ON(i == 0 && extra != 0);
363
364 if (pcpu_size[i] < 0 || pcpu_size[i] < extra + size)
365 continue;
366
367 /* Transfer extra to previous block. */
368 if (pcpu_size[i-1] < 0)
369 pcpu_size[i-1] -= extra;
370 else
371 pcpu_size[i-1] += extra;
372 pcpu_size[i] -= extra;
373 ptr += extra;
374
375 /* Split block if warranted */
376 if (pcpu_size[i] - size > sizeof(unsigned long))
377 if (!split_block(i, size))
378 return NULL;
379
380 /* Mark allocated */
381 pcpu_size[i] = -pcpu_size[i];
382 return ptr;
383 }
384
385 printk(KERN_WARNING "Could not allocate %lu bytes percpu data\n",
386 size);
387 return NULL;
388 }
389
390 static void percpu_modfree(void *freeme)
391 {
392 unsigned int i;
393 void *ptr = __per_cpu_start + block_size(pcpu_size[0]);
394
395 /* First entry is core kernel percpu data. */
396 for (i = 1; i < pcpu_num_used; ptr += block_size(pcpu_size[i]), i++) {
397 if (ptr == freeme) {
398 pcpu_size[i] = -pcpu_size[i];
399 goto free;
400 }
401 }
402 BUG();
403
404 free:
405 /* Merge with previous? */
406 if (pcpu_size[i-1] >= 0) {
407 pcpu_size[i-1] += pcpu_size[i];
408 pcpu_num_used--;
409 memmove(&pcpu_size[i], &pcpu_size[i+1],
410 (pcpu_num_used - i) * sizeof(pcpu_size[0]));
411 i--;
412 }
413 /* Merge with next? */
414 if (i+1 < pcpu_num_used && pcpu_size[i+1] >= 0) {
415 pcpu_size[i] += pcpu_size[i+1];
416 pcpu_num_used--;
417 memmove(&pcpu_size[i+1], &pcpu_size[i+2],
418 (pcpu_num_used - (i+1)) * sizeof(pcpu_size[0]));
419 }
420 }
421
422 static unsigned int find_pcpusec(Elf_Ehdr *hdr,
423 Elf_Shdr *sechdrs,
424 const char *secstrings)
425 {
426 return find_sec(hdr, sechdrs, secstrings, ".data.percpu");
427 }
428
429 static int percpu_modinit(void)
430 {
431 pcpu_num_used = 2;
432 pcpu_num_allocated = 2;
433 pcpu_size = kmalloc(sizeof(pcpu_size[0]) * pcpu_num_allocated,
434 GFP_KERNEL);
435 /* Static in-kernel percpu data (used). */
436 pcpu_size[0] = -(__per_cpu_end-__per_cpu_start);
437 /* Free room. */
438 pcpu_size[1] = PERCPU_ENOUGH_ROOM + pcpu_size[0];
439 if (pcpu_size[1] < 0) {
440 printk(KERN_ERR "No per-cpu room for modules.\n");
441 pcpu_num_used = 1;
442 }
443
444 return 0;
445 }
446 __initcall(percpu_modinit);
447 #else /* ... !CONFIG_SMP */
448 static inline void *percpu_modalloc(unsigned long size, unsigned long align,
449 const char *name)
450 {
451 return NULL;
452 }
453 static inline void percpu_modfree(void *pcpuptr)
454 {
455 BUG();
456 }
457 static inline unsigned int find_pcpusec(Elf_Ehdr *hdr,
458 Elf_Shdr *sechdrs,
459 const char *secstrings)
460 {
461 return 0;
462 }
463 static inline void percpu_modcopy(void *pcpudst, const void *src,
464 unsigned long size)
465 {
466 /* pcpusec should be 0, and size of that section should be 0. */
467 BUG_ON(size != 0);
468 }
469 #endif /* CONFIG_SMP */
470
471 #define MODINFO_ATTR(field) \
472 static void setup_modinfo_##field(struct module *mod, const char *s) \
473 { \
474 mod->field = kstrdup(s, GFP_KERNEL); \
475 } \
476 static ssize_t show_modinfo_##field(struct module_attribute *mattr, \
477 struct module *mod, char *buffer) \
478 { \
479 return sprintf(buffer, "%s\n", mod->field); \
480 } \
481 static int modinfo_##field##_exists(struct module *mod) \
482 { \
483 return mod->field != NULL; \
484 } \
485 static void free_modinfo_##field(struct module *mod) \
486 { \
487 kfree(mod->field); \
488 mod->field = NULL; \
489 } \
490 static struct module_attribute modinfo_##field = { \
491 .attr = { .name = __stringify(field), .mode = 0444 }, \
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 },
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 },
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.mode = S_IRUGO;
1035 *(gattr++) = &(sattr++)->mattr.attr;
1036 }
1037 *gattr = NULL;
1038
1039 if (sysfs_create_group(&mod->mkobj.kobj, &sect_attrs->grp))
1040 goto out;
1041
1042 mod->sect_attrs = sect_attrs;
1043 return;
1044 out:
1045 free_sect_attrs(sect_attrs);
1046 }
1047
1048 static void remove_sect_attrs(struct module *mod)
1049 {
1050 if (mod->sect_attrs) {
1051 sysfs_remove_group(&mod->mkobj.kobj,
1052 &mod->sect_attrs->grp);
1053 /* We are positive that no one is using any sect attrs
1054 * at this point. Deallocate immediately. */
1055 free_sect_attrs(mod->sect_attrs);
1056 mod->sect_attrs = NULL;
1057 }
1058 }
1059
1060 #else
1061
1062 static inline void add_sect_attrs(struct module *mod, unsigned int nsect,
1063 char *sectstrings, Elf_Shdr *sechdrs)
1064 {
1065 }
1066
1067 static inline void remove_sect_attrs(struct module *mod)
1068 {
1069 }
1070 #endif /* CONFIG_KALLSYMS */
1071
1072 #ifdef CONFIG_SYSFS
1073 int module_add_modinfo_attrs(struct module *mod)
1074 {
1075 struct module_attribute *attr;
1076 struct module_attribute *temp_attr;
1077 int error = 0;
1078 int i;
1079
1080 mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
1081 (ARRAY_SIZE(modinfo_attrs) + 1)),
1082 GFP_KERNEL);
1083 if (!mod->modinfo_attrs)
1084 return -ENOMEM;
1085
1086 temp_attr = mod->modinfo_attrs;
1087 for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
1088 if (!attr->test ||
1089 (attr->test && attr->test(mod))) {
1090 memcpy(temp_attr, attr, sizeof(*temp_attr));
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_sysfs_initialized) {
1121 printk(KERN_ERR "%s: module sysfs 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 err = -ENOMEM;
1153 goto out_unreg;
1154 }
1155
1156 err = module_param_sysfs_setup(mod, kparam, num_params);
1157 if (err)
1158 goto out_unreg_holders;
1159
1160 err = module_add_modinfo_attrs(mod);
1161 if (err)
1162 goto out_unreg_param;
1163
1164 kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
1165 return 0;
1166
1167 out_unreg_param:
1168 module_param_sysfs_remove(mod);
1169 out_unreg_holders:
1170 kobject_unregister(mod->holders_dir);
1171 out_unreg:
1172 kobject_del(&mod->mkobj.kobj);
1173 kobject_put(&mod->mkobj.kobj);
1174 out:
1175 return err;
1176 }
1177 #endif
1178
1179 static void mod_kobject_remove(struct module *mod)
1180 {
1181 module_remove_modinfo_attrs(mod);
1182 module_param_sysfs_remove(mod);
1183 kobject_unregister(mod->mkobj.drivers_dir);
1184 kobject_unregister(mod->holders_dir);
1185 kobject_unregister(&mod->mkobj.kobj);
1186 }
1187
1188 /*
1189 * unlink the module with the whole machine is stopped with interrupts off
1190 * - this defends against kallsyms not taking locks
1191 */
1192 static int __unlink_module(void *_mod)
1193 {
1194 struct module *mod = _mod;
1195 list_del(&mod->list);
1196 return 0;
1197 }
1198
1199 /* Free a module, remove from lists, etc (must hold module_mutex). */
1200 static void free_module(struct module *mod)
1201 {
1202 /* Delete from various lists */
1203 stop_machine_run(__unlink_module, mod, NR_CPUS);
1204 remove_sect_attrs(mod);
1205 mod_kobject_remove(mod);
1206
1207 unwind_remove_table(mod->unwind_info, 0);
1208
1209 /* Arch-specific cleanup. */
1210 module_arch_cleanup(mod);
1211
1212 /* Module unload stuff */
1213 module_unload_free(mod);
1214
1215 /* This may be NULL, but that's OK */
1216 module_free(mod, mod->module_init);
1217 kfree(mod->args);
1218 if (mod->percpu)
1219 percpu_modfree(mod->percpu);
1220
1221 /* Free lock-classes: */
1222 lockdep_free_key_range(mod->module_core, mod->core_size);
1223
1224 /* Finally, free the core (containing the module structure) */
1225 module_free(mod, mod->module_core);
1226 }
1227
1228 void *__symbol_get(const char *symbol)
1229 {
1230 struct module *owner;
1231 unsigned long value, flags;
1232 const unsigned long *crc;
1233
1234 spin_lock_irqsave(&modlist_lock, flags);
1235 value = __find_symbol(symbol, &owner, &crc, 1);
1236 if (value && !strong_try_module_get(owner))
1237 value = 0;
1238 spin_unlock_irqrestore(&modlist_lock, flags);
1239
1240 return (void *)value;
1241 }
1242 EXPORT_SYMBOL_GPL(__symbol_get);
1243
1244 /*
1245 * Ensure that an exported symbol [global namespace] does not already exist
1246 * in the kernel or in some other module's exported symbol table.
1247 */
1248 static int verify_export_symbols(struct module *mod)
1249 {
1250 const char *name = NULL;
1251 unsigned long i, ret = 0;
1252 struct module *owner;
1253 const unsigned long *crc;
1254
1255 for (i = 0; i < mod->num_syms; i++)
1256 if (__find_symbol(mod->syms[i].name, &owner, &crc, 1)) {
1257 name = mod->syms[i].name;
1258 ret = -ENOEXEC;
1259 goto dup;
1260 }
1261
1262 for (i = 0; i < mod->num_gpl_syms; i++)
1263 if (__find_symbol(mod->gpl_syms[i].name, &owner, &crc, 1)) {
1264 name = mod->gpl_syms[i].name;
1265 ret = -ENOEXEC;
1266 goto dup;
1267 }
1268
1269 dup:
1270 if (ret)
1271 printk(KERN_ERR "%s: exports duplicate symbol %s (owned by %s)\n",
1272 mod->name, name, module_name(owner));
1273
1274 return ret;
1275 }
1276
1277 /* Change all symbols so that sh_value encodes the pointer directly. */
1278 static int simplify_symbols(Elf_Shdr *sechdrs,
1279 unsigned int symindex,
1280 const char *strtab,
1281 unsigned int versindex,
1282 unsigned int pcpuindex,
1283 struct module *mod)
1284 {
1285 Elf_Sym *sym = (void *)sechdrs[symindex].sh_addr;
1286 unsigned long secbase;
1287 unsigned int i, n = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
1288 int ret = 0;
1289
1290 for (i = 1; i < n; i++) {
1291 switch (sym[i].st_shndx) {
1292 case SHN_COMMON:
1293 /* We compiled with -fno-common. These are not
1294 supposed to happen. */
1295 DEBUGP("Common symbol: %s\n", strtab + sym[i].st_name);
1296 printk("%s: please compile with -fno-common\n",
1297 mod->name);
1298 ret = -ENOEXEC;
1299 break;
1300
1301 case SHN_ABS:
1302 /* Don't need to do anything */
1303 DEBUGP("Absolute symbol: 0x%08lx\n",
1304 (long)sym[i].st_value);
1305 break;
1306
1307 case SHN_UNDEF:
1308 sym[i].st_value
1309 = resolve_symbol(sechdrs, versindex,
1310 strtab + sym[i].st_name, mod);
1311
1312 /* Ok if resolved. */
1313 if (sym[i].st_value != 0)
1314 break;
1315 /* Ok if weak. */
1316 if (ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
1317 break;
1318
1319 printk(KERN_WARNING "%s: Unknown symbol %s\n",
1320 mod->name, strtab + sym[i].st_name);
1321 ret = -ENOENT;
1322 break;
1323
1324 default:
1325 /* Divert to percpu allocation if a percpu var. */
1326 if (sym[i].st_shndx == pcpuindex)
1327 secbase = (unsigned long)mod->percpu;
1328 else
1329 secbase = sechdrs[sym[i].st_shndx].sh_addr;
1330 sym[i].st_value += secbase;
1331 break;
1332 }
1333 }
1334
1335 return ret;
1336 }
1337
1338 /* Update size with this section: return offset. */
1339 static long get_offset(unsigned long *size, Elf_Shdr *sechdr)
1340 {
1341 long ret;
1342
1343 ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
1344 *size = ret + sechdr->sh_size;
1345 return ret;
1346 }
1347
1348 /* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
1349 might -- code, read-only data, read-write data, small data. Tally
1350 sizes, and place the offsets into sh_entsize fields: high bit means it
1351 belongs in init. */
1352 static void layout_sections(struct module *mod,
1353 const Elf_Ehdr *hdr,
1354 Elf_Shdr *sechdrs,
1355 const char *secstrings)
1356 {
1357 static unsigned long const masks[][2] = {
1358 /* NOTE: all executable code must be the first section
1359 * in this array; otherwise modify the text_size
1360 * finder in the two loops below */
1361 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
1362 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
1363 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
1364 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
1365 };
1366 unsigned int m, i;
1367
1368 for (i = 0; i < hdr->e_shnum; i++)
1369 sechdrs[i].sh_entsize = ~0UL;
1370
1371 DEBUGP("Core section allocation order:\n");
1372 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
1373 for (i = 0; i < hdr->e_shnum; ++i) {
1374 Elf_Shdr *s = &sechdrs[i];
1375
1376 if ((s->sh_flags & masks[m][0]) != masks[m][0]
1377 || (s->sh_flags & masks[m][1])
1378 || s->sh_entsize != ~0UL
1379 || strncmp(secstrings + s->sh_name,
1380 ".init", 5) == 0)
1381 continue;
1382 s->sh_entsize = get_offset(&mod->core_size, s);
1383 DEBUGP("\t%s\n", secstrings + s->sh_name);
1384 }
1385 if (m == 0)
1386 mod->core_text_size = mod->core_size;
1387 }
1388
1389 DEBUGP("Init section allocation order:\n");
1390 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
1391 for (i = 0; i < hdr->e_shnum; ++i) {
1392 Elf_Shdr *s = &sechdrs[i];
1393
1394 if ((s->sh_flags & masks[m][0]) != masks[m][0]
1395 || (s->sh_flags & masks[m][1])
1396 || s->sh_entsize != ~0UL
1397 || strncmp(secstrings + s->sh_name,
1398 ".init", 5) != 0)
1399 continue;
1400 s->sh_entsize = (get_offset(&mod->init_size, s)
1401 | INIT_OFFSET_MASK);
1402 DEBUGP("\t%s\n", secstrings + s->sh_name);
1403 }
1404 if (m == 0)
1405 mod->init_text_size = mod->init_size;
1406 }
1407 }
1408
1409 static void set_license(struct module *mod, const char *license)
1410 {
1411 if (!license)
1412 license = "unspecified";
1413
1414 if (!license_is_gpl_compatible(license)) {
1415 if (!(tainted & TAINT_PROPRIETARY_MODULE))
1416 printk(KERN_WARNING "%s: module license '%s' taints "
1417 "kernel.\n", mod->name, license);
1418 add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
1419 }
1420 }
1421
1422 /* Parse tag=value strings from .modinfo section */
1423 static char *next_string(char *string, unsigned long *secsize)
1424 {
1425 /* Skip non-zero chars */
1426 while (string[0]) {
1427 string++;
1428 if ((*secsize)-- <= 1)
1429 return NULL;
1430 }
1431
1432 /* Skip any zero padding. */
1433 while (!string[0]) {
1434 string++;
1435 if ((*secsize)-- <= 1)
1436 return NULL;
1437 }
1438 return string;
1439 }
1440
1441 static char *get_modinfo(Elf_Shdr *sechdrs,
1442 unsigned int info,
1443 const char *tag)
1444 {
1445 char *p;
1446 unsigned int taglen = strlen(tag);
1447 unsigned long size = sechdrs[info].sh_size;
1448
1449 for (p = (char *)sechdrs[info].sh_addr; p; p = next_string(p, &size)) {
1450 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
1451 return p + taglen + 1;
1452 }
1453 return NULL;
1454 }
1455
1456 static void setup_modinfo(struct module *mod, Elf_Shdr *sechdrs,
1457 unsigned int infoindex)
1458 {
1459 struct module_attribute *attr;
1460 int i;
1461
1462 for (i = 0; (attr = modinfo_attrs[i]); i++) {
1463 if (attr->setup)
1464 attr->setup(mod,
1465 get_modinfo(sechdrs,
1466 infoindex,
1467 attr->attr.name));
1468 }
1469 }
1470
1471 #ifdef CONFIG_KALLSYMS
1472 static int is_exported(const char *name, const struct module *mod)
1473 {
1474 if (!mod && lookup_symbol(name, __start___ksymtab, __stop___ksymtab))
1475 return 1;
1476 else
1477 if (mod && lookup_symbol(name, mod->syms, mod->syms + mod->num_syms))
1478 return 1;
1479 else
1480 return 0;
1481 }
1482
1483 /* As per nm */
1484 static char elf_type(const Elf_Sym *sym,
1485 Elf_Shdr *sechdrs,
1486 const char *secstrings,
1487 struct module *mod)
1488 {
1489 if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
1490 if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
1491 return 'v';
1492 else
1493 return 'w';
1494 }
1495 if (sym->st_shndx == SHN_UNDEF)
1496 return 'U';
1497 if (sym->st_shndx == SHN_ABS)
1498 return 'a';
1499 if (sym->st_shndx >= SHN_LORESERVE)
1500 return '?';
1501 if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
1502 return 't';
1503 if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
1504 && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
1505 if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
1506 return 'r';
1507 else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
1508 return 'g';
1509 else
1510 return 'd';
1511 }
1512 if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
1513 if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
1514 return 's';
1515 else
1516 return 'b';
1517 }
1518 if (strncmp(secstrings + sechdrs[sym->st_shndx].sh_name,
1519 ".debug", strlen(".debug")) == 0)
1520 return 'n';
1521 return '?';
1522 }
1523
1524 static void add_kallsyms(struct module *mod,
1525 Elf_Shdr *sechdrs,
1526 unsigned int symindex,
1527 unsigned int strindex,
1528 const char *secstrings)
1529 {
1530 unsigned int i;
1531
1532 mod->symtab = (void *)sechdrs[symindex].sh_addr;
1533 mod->num_symtab = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
1534 mod->strtab = (void *)sechdrs[strindex].sh_addr;
1535
1536 /* Set types up while we still have access to sections. */
1537 for (i = 0; i < mod->num_symtab; i++)
1538 mod->symtab[i].st_info
1539 = elf_type(&mod->symtab[i], sechdrs, secstrings, mod);
1540 }
1541 #else
1542 static inline void add_kallsyms(struct module *mod,
1543 Elf_Shdr *sechdrs,
1544 unsigned int symindex,
1545 unsigned int strindex,
1546 const char *secstrings)
1547 {
1548 }
1549 #endif /* CONFIG_KALLSYMS */
1550
1551 /* Allocate and load the module: note that size of section 0 is always
1552 zero, and we rely on this for optional sections. */
1553 static struct module *load_module(void __user *umod,
1554 unsigned long len,
1555 const char __user *uargs)
1556 {
1557 Elf_Ehdr *hdr;
1558 Elf_Shdr *sechdrs;
1559 char *secstrings, *args, *modmagic, *strtab = NULL;
1560 unsigned int i;
1561 unsigned int symindex = 0;
1562 unsigned int strindex = 0;
1563 unsigned int setupindex;
1564 unsigned int exindex;
1565 unsigned int exportindex;
1566 unsigned int modindex;
1567 unsigned int obsparmindex;
1568 unsigned int infoindex;
1569 unsigned int gplindex;
1570 unsigned int crcindex;
1571 unsigned int gplcrcindex;
1572 unsigned int versindex;
1573 unsigned int pcpuindex;
1574 unsigned int gplfutureindex;
1575 unsigned int gplfuturecrcindex;
1576 unsigned int unwindex = 0;
1577 unsigned int unusedindex;
1578 unsigned int unusedcrcindex;
1579 unsigned int unusedgplindex;
1580 unsigned int unusedgplcrcindex;
1581 struct module *mod;
1582 long err = 0;
1583 void *percpu = NULL, *ptr = NULL; /* Stops spurious gcc warning */
1584 struct exception_table_entry *extable;
1585 mm_segment_t old_fs;
1586
1587 DEBUGP("load_module: umod=%p, len=%lu, uargs=%p\n",
1588 umod, len, uargs);
1589 if (len < sizeof(*hdr))
1590 return ERR_PTR(-ENOEXEC);
1591
1592 /* Suck in entire file: we'll want most of it. */
1593 /* vmalloc barfs on "unusual" numbers. Check here */
1594 if (len > 64 * 1024 * 1024 || (hdr = vmalloc(len)) == NULL)
1595 return ERR_PTR(-ENOMEM);
1596 if (copy_from_user(hdr, umod, len) != 0) {
1597 err = -EFAULT;
1598 goto free_hdr;
1599 }
1600
1601 /* Sanity checks against insmoding binaries or wrong arch,
1602 weird elf version */
1603 if (memcmp(hdr->e_ident, ELFMAG, 4) != 0
1604 || hdr->e_type != ET_REL
1605 || !elf_check_arch(hdr)
1606 || hdr->e_shentsize != sizeof(*sechdrs)) {
1607 err = -ENOEXEC;
1608 goto free_hdr;
1609 }
1610
1611 if (len < hdr->e_shoff + hdr->e_shnum * sizeof(Elf_Shdr))
1612 goto truncated;
1613
1614 /* Convenience variables */
1615 sechdrs = (void *)hdr + hdr->e_shoff;
1616 secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
1617 sechdrs[0].sh_addr = 0;
1618
1619 for (i = 1; i < hdr->e_shnum; i++) {
1620 if (sechdrs[i].sh_type != SHT_NOBITS
1621 && len < sechdrs[i].sh_offset + sechdrs[i].sh_size)
1622 goto truncated;
1623
1624 /* Mark all sections sh_addr with their address in the
1625 temporary image. */
1626 sechdrs[i].sh_addr = (size_t)hdr + sechdrs[i].sh_offset;
1627
1628 /* Internal symbols and strings. */
1629 if (sechdrs[i].sh_type == SHT_SYMTAB) {
1630 symindex = i;
1631 strindex = sechdrs[i].sh_link;
1632 strtab = (char *)hdr + sechdrs[strindex].sh_offset;
1633 }
1634 #ifndef CONFIG_MODULE_UNLOAD
1635 /* Don't load .exit sections */
1636 if (strncmp(secstrings+sechdrs[i].sh_name, ".exit", 5) == 0)
1637 sechdrs[i].sh_flags &= ~(unsigned long)SHF_ALLOC;
1638 #endif
1639 }
1640
1641 modindex = find_sec(hdr, sechdrs, secstrings,
1642 ".gnu.linkonce.this_module");
1643 if (!modindex) {
1644 printk(KERN_WARNING "No module found in object\n");
1645 err = -ENOEXEC;
1646 goto free_hdr;
1647 }
1648 mod = (void *)sechdrs[modindex].sh_addr;
1649
1650 if (symindex == 0) {
1651 printk(KERN_WARNING "%s: module has no symbols (stripped?)\n",
1652 mod->name);
1653 err = -ENOEXEC;
1654 goto free_hdr;
1655 }
1656
1657 /* Optional sections */
1658 exportindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab");
1659 gplindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_gpl");
1660 gplfutureindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_gpl_future");
1661 unusedindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_unused");
1662 unusedgplindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_unused_gpl");
1663 crcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab");
1664 gplcrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_gpl");
1665 gplfuturecrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_gpl_future");
1666 unusedcrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_unused");
1667 unusedgplcrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_unused_gpl");
1668 setupindex = find_sec(hdr, sechdrs, secstrings, "__param");
1669 exindex = find_sec(hdr, sechdrs, secstrings, "__ex_table");
1670 obsparmindex = find_sec(hdr, sechdrs, secstrings, "__obsparm");
1671 versindex = find_sec(hdr, sechdrs, secstrings, "__versions");
1672 infoindex = find_sec(hdr, sechdrs, secstrings, ".modinfo");
1673 pcpuindex = find_pcpusec(hdr, sechdrs, secstrings);
1674 #ifdef ARCH_UNWIND_SECTION_NAME
1675 unwindex = find_sec(hdr, sechdrs, secstrings, ARCH_UNWIND_SECTION_NAME);
1676 #endif
1677
1678 /* Don't keep modinfo section */
1679 sechdrs[infoindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
1680 #ifdef CONFIG_KALLSYMS
1681 /* Keep symbol and string tables for decoding later. */
1682 sechdrs[symindex].sh_flags |= SHF_ALLOC;
1683 sechdrs[strindex].sh_flags |= SHF_ALLOC;
1684 #endif
1685 if (unwindex)
1686 sechdrs[unwindex].sh_flags |= SHF_ALLOC;
1687
1688 /* Check module struct version now, before we try to use module. */
1689 if (!check_modstruct_version(sechdrs, versindex, mod)) {
1690 err = -ENOEXEC;
1691 goto free_hdr;
1692 }
1693
1694 modmagic = get_modinfo(sechdrs, infoindex, "vermagic");
1695 /* This is allowed: modprobe --force will invalidate it. */
1696 if (!modmagic) {
1697 add_taint_module(mod, TAINT_FORCED_MODULE);
1698 printk(KERN_WARNING "%s: no version magic, tainting kernel.\n",
1699 mod->name);
1700 } else if (!same_magic(modmagic, vermagic)) {
1701 printk(KERN_ERR "%s: version magic '%s' should be '%s'\n",
1702 mod->name, modmagic, vermagic);
1703 err = -ENOEXEC;
1704 goto free_hdr;
1705 }
1706
1707 /* Now copy in args */
1708 args = strndup_user(uargs, ~0UL >> 1);
1709 if (IS_ERR(args)) {
1710 err = PTR_ERR(args);
1711 goto free_hdr;
1712 }
1713
1714 if (find_module(mod->name)) {
1715 err = -EEXIST;
1716 goto free_mod;
1717 }
1718
1719 mod->state = MODULE_STATE_COMING;
1720
1721 /* Allow arches to frob section contents and sizes. */
1722 err = module_frob_arch_sections(hdr, sechdrs, secstrings, mod);
1723 if (err < 0)
1724 goto free_mod;
1725
1726 if (pcpuindex) {
1727 /* We have a special allocation for this section. */
1728 percpu = percpu_modalloc(sechdrs[pcpuindex].sh_size,
1729 sechdrs[pcpuindex].sh_addralign,
1730 mod->name);
1731 if (!percpu) {
1732 err = -ENOMEM;
1733 goto free_mod;
1734 }
1735 sechdrs[pcpuindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
1736 mod->percpu = percpu;
1737 }
1738
1739 /* Determine total sizes, and put offsets in sh_entsize. For now
1740 this is done generically; there doesn't appear to be any
1741 special cases for the architectures. */
1742 layout_sections(mod, hdr, sechdrs, secstrings);
1743
1744 /* Do the allocs. */
1745 ptr = module_alloc(mod->core_size);
1746 if (!ptr) {
1747 err = -ENOMEM;
1748 goto free_percpu;
1749 }
1750 memset(ptr, 0, mod->core_size);
1751 mod->module_core = ptr;
1752
1753 ptr = module_alloc(mod->init_size);
1754 if (!ptr && mod->init_size) {
1755 err = -ENOMEM;
1756 goto free_core;
1757 }
1758 memset(ptr, 0, mod->init_size);
1759 mod->module_init = ptr;
1760
1761 /* Transfer each section which specifies SHF_ALLOC */
1762 DEBUGP("final section addresses:\n");
1763 for (i = 0; i < hdr->e_shnum; i++) {
1764 void *dest;
1765
1766 if (!(sechdrs[i].sh_flags & SHF_ALLOC))
1767 continue;
1768
1769 if (sechdrs[i].sh_entsize & INIT_OFFSET_MASK)
1770 dest = mod->module_init
1771 + (sechdrs[i].sh_entsize & ~INIT_OFFSET_MASK);
1772 else
1773 dest = mod->module_core + sechdrs[i].sh_entsize;
1774
1775 if (sechdrs[i].sh_type != SHT_NOBITS)
1776 memcpy(dest, (void *)sechdrs[i].sh_addr,
1777 sechdrs[i].sh_size);
1778 /* Update sh_addr to point to copy in image. */
1779 sechdrs[i].sh_addr = (unsigned long)dest;
1780 DEBUGP("\t0x%lx %s\n", sechdrs[i].sh_addr, secstrings + sechdrs[i].sh_name);
1781 }
1782 /* Module has been moved. */
1783 mod = (void *)sechdrs[modindex].sh_addr;
1784
1785 /* Now we've moved module, initialize linked lists, etc. */
1786 module_unload_init(mod);
1787
1788 /* Initialize kobject, so we can reference it. */
1789 if (mod_sysfs_init(mod) != 0)
1790 goto cleanup;
1791
1792 /* Set up license info based on the info section */
1793 set_license(mod, get_modinfo(sechdrs, infoindex, "license"));
1794
1795 if (strcmp(mod->name, "ndiswrapper") == 0)
1796 add_taint(TAINT_PROPRIETARY_MODULE);
1797 if (strcmp(mod->name, "driverloader") == 0)
1798 add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
1799
1800 /* Set up MODINFO_ATTR fields */
1801 setup_modinfo(mod, sechdrs, infoindex);
1802
1803 /* Fix up syms, so that st_value is a pointer to location. */
1804 err = simplify_symbols(sechdrs, symindex, strtab, versindex, pcpuindex,
1805 mod);
1806 if (err < 0)
1807 goto cleanup;
1808
1809 /* Set up EXPORTed & EXPORT_GPLed symbols (section 0 is 0 length) */
1810 mod->num_syms = sechdrs[exportindex].sh_size / sizeof(*mod->syms);
1811 mod->syms = (void *)sechdrs[exportindex].sh_addr;
1812 if (crcindex)
1813 mod->crcs = (void *)sechdrs[crcindex].sh_addr;
1814 mod->num_gpl_syms = sechdrs[gplindex].sh_size / sizeof(*mod->gpl_syms);
1815 mod->gpl_syms = (void *)sechdrs[gplindex].sh_addr;
1816 if (gplcrcindex)
1817 mod->gpl_crcs = (void *)sechdrs[gplcrcindex].sh_addr;
1818 mod->num_gpl_future_syms = sechdrs[gplfutureindex].sh_size /
1819 sizeof(*mod->gpl_future_syms);
1820 mod->num_unused_syms = sechdrs[unusedindex].sh_size /
1821 sizeof(*mod->unused_syms);
1822 mod->num_unused_gpl_syms = sechdrs[unusedgplindex].sh_size /
1823 sizeof(*mod->unused_gpl_syms);
1824 mod->gpl_future_syms = (void *)sechdrs[gplfutureindex].sh_addr;
1825 if (gplfuturecrcindex)
1826 mod->gpl_future_crcs = (void *)sechdrs[gplfuturecrcindex].sh_addr;
1827
1828 mod->unused_syms = (void *)sechdrs[unusedindex].sh_addr;
1829 if (unusedcrcindex)
1830 mod->unused_crcs = (void *)sechdrs[unusedcrcindex].sh_addr;
1831 mod->unused_gpl_syms = (void *)sechdrs[unusedgplindex].sh_addr;
1832 if (unusedgplcrcindex)
1833 mod->unused_crcs = (void *)sechdrs[unusedgplcrcindex].sh_addr;
1834
1835 #ifdef CONFIG_MODVERSIONS
1836 if ((mod->num_syms && !crcindex) ||
1837 (mod->num_gpl_syms && !gplcrcindex) ||
1838 (mod->num_gpl_future_syms && !gplfuturecrcindex) ||
1839 (mod->num_unused_syms && !unusedcrcindex) ||
1840 (mod->num_unused_gpl_syms && !unusedgplcrcindex)) {
1841 printk(KERN_WARNING "%s: No versions for exported symbols."
1842 " Tainting kernel.\n", mod->name);
1843 add_taint_module(mod, TAINT_FORCED_MODULE);
1844 }
1845 #endif
1846
1847 /* Now do relocations. */
1848 for (i = 1; i < hdr->e_shnum; i++) {
1849 const char *strtab = (char *)sechdrs[strindex].sh_addr;
1850 unsigned int info = sechdrs[i].sh_info;
1851
1852 /* Not a valid relocation section? */
1853 if (info >= hdr->e_shnum)
1854 continue;
1855
1856 /* Don't bother with non-allocated sections */
1857 if (!(sechdrs[info].sh_flags & SHF_ALLOC))
1858 continue;
1859
1860 if (sechdrs[i].sh_type == SHT_REL)
1861 err = apply_relocate(sechdrs, strtab, symindex, i,mod);
1862 else if (sechdrs[i].sh_type == SHT_RELA)
1863 err = apply_relocate_add(sechdrs, strtab, symindex, i,
1864 mod);
1865 if (err < 0)
1866 goto cleanup;
1867 }
1868
1869 /* Find duplicate symbols */
1870 err = verify_export_symbols(mod);
1871
1872 if (err < 0)
1873 goto cleanup;
1874
1875 /* Set up and sort exception table */
1876 mod->num_exentries = sechdrs[exindex].sh_size / sizeof(*mod->extable);
1877 mod->extable = extable = (void *)sechdrs[exindex].sh_addr;
1878 sort_extable(extable, extable + mod->num_exentries);
1879
1880 /* Finally, copy percpu area over. */
1881 percpu_modcopy(mod->percpu, (void *)sechdrs[pcpuindex].sh_addr,
1882 sechdrs[pcpuindex].sh_size);
1883
1884 add_kallsyms(mod, sechdrs, symindex, strindex, secstrings);
1885
1886 err = module_finalize(hdr, sechdrs, mod);
1887 if (err < 0)
1888 goto cleanup;
1889
1890 /* flush the icache in correct context */
1891 old_fs = get_fs();
1892 set_fs(KERNEL_DS);
1893
1894 /*
1895 * Flush the instruction cache, since we've played with text.
1896 * Do it before processing of module parameters, so the module
1897 * can provide parameter accessor functions of its own.
1898 */
1899 if (mod->module_init)
1900 flush_icache_range((unsigned long)mod->module_init,
1901 (unsigned long)mod->module_init
1902 + mod->init_size);
1903 flush_icache_range((unsigned long)mod->module_core,
1904 (unsigned long)mod->module_core + mod->core_size);
1905
1906 set_fs(old_fs);
1907
1908 mod->args = args;
1909 if (obsparmindex)
1910 printk(KERN_WARNING "%s: Ignoring obsolete parameters\n",
1911 mod->name);
1912
1913 /* Size of section 0 is 0, so this works well if no params */
1914 err = parse_args(mod->name, mod->args,
1915 (struct kernel_param *)
1916 sechdrs[setupindex].sh_addr,
1917 sechdrs[setupindex].sh_size
1918 / sizeof(struct kernel_param),
1919 NULL);
1920 if (err < 0)
1921 goto arch_cleanup;
1922
1923 err = mod_sysfs_setup(mod,
1924 (struct kernel_param *)
1925 sechdrs[setupindex].sh_addr,
1926 sechdrs[setupindex].sh_size
1927 / sizeof(struct kernel_param));
1928 if (err < 0)
1929 goto arch_cleanup;
1930 add_sect_attrs(mod, hdr->e_shnum, secstrings, sechdrs);
1931
1932 /* Size of section 0 is 0, so this works well if no unwind info. */
1933 mod->unwind_info = unwind_add_table(mod,
1934 (void *)sechdrs[unwindex].sh_addr,
1935 sechdrs[unwindex].sh_size);
1936
1937 /* Get rid of temporary copy */
1938 vfree(hdr);
1939
1940 /* Done! */
1941 return mod;
1942
1943 arch_cleanup:
1944 module_arch_cleanup(mod);
1945 cleanup:
1946 module_unload_free(mod);
1947 module_free(mod, mod->module_init);
1948 free_core:
1949 module_free(mod, mod->module_core);
1950 free_percpu:
1951 if (percpu)
1952 percpu_modfree(percpu);
1953 free_mod:
1954 kfree(args);
1955 free_hdr:
1956 vfree(hdr);
1957 return ERR_PTR(err);
1958
1959 truncated:
1960 printk(KERN_ERR "Module len %lu truncated\n", len);
1961 err = -ENOEXEC;
1962 goto free_hdr;
1963 }
1964
1965 /*
1966 * link the module with the whole machine is stopped with interrupts off
1967 * - this defends against kallsyms not taking locks
1968 */
1969 static int __link_module(void *_mod)
1970 {
1971 struct module *mod = _mod;
1972 list_add(&mod->list, &modules);
1973 return 0;
1974 }
1975
1976 /* This is where the real work happens */
1977 asmlinkage long
1978 sys_init_module(void __user *umod,
1979 unsigned long len,
1980 const char __user *uargs)
1981 {
1982 struct module *mod;
1983 int ret = 0;
1984
1985 /* Must have permission */
1986 if (!capable(CAP_SYS_MODULE))
1987 return -EPERM;
1988
1989 /* Only one module load at a time, please */
1990 if (mutex_lock_interruptible(&module_mutex) != 0)
1991 return -EINTR;
1992
1993 /* Do all the hard work */
1994 mod = load_module(umod, len, uargs);
1995 if (IS_ERR(mod)) {
1996 mutex_unlock(&module_mutex);
1997 return PTR_ERR(mod);
1998 }
1999
2000 /* Now sew it into the lists. They won't access us, since
2001 strong_try_module_get() will fail. */
2002 stop_machine_run(__link_module, mod, NR_CPUS);
2003
2004 /* Drop lock so they can recurse */
2005 mutex_unlock(&module_mutex);
2006
2007 blocking_notifier_call_chain(&module_notify_list,
2008 MODULE_STATE_COMING, mod);
2009
2010 /* Start the module */
2011 if (mod->init != NULL)
2012 ret = mod->init();
2013 if (ret < 0) {
2014 /* Init routine failed: abort. Try to protect us from
2015 buggy refcounters. */
2016 mod->state = MODULE_STATE_GOING;
2017 synchronize_sched();
2018 if (mod->unsafe)
2019 printk(KERN_ERR "%s: module is now stuck!\n",
2020 mod->name);
2021 else {
2022 module_put(mod);
2023 mutex_lock(&module_mutex);
2024 free_module(mod);
2025 mutex_unlock(&module_mutex);
2026 }
2027 return ret;
2028 }
2029
2030 /* Now it's a first class citizen! */
2031 mutex_lock(&module_mutex);
2032 mod->state = MODULE_STATE_LIVE;
2033 /* Drop initial reference. */
2034 module_put(mod);
2035 unwind_remove_table(mod->unwind_info, 1);
2036 module_free(mod, mod->module_init);
2037 mod->module_init = NULL;
2038 mod->init_size = 0;
2039 mod->init_text_size = 0;
2040 mutex_unlock(&module_mutex);
2041
2042 return 0;
2043 }
2044
2045 static inline int within(unsigned long addr, void *start, unsigned long size)
2046 {
2047 return ((void *)addr >= start && (void *)addr < start + size);
2048 }
2049
2050 #ifdef CONFIG_KALLSYMS
2051 /*
2052 * This ignores the intensely annoying "mapping symbols" found
2053 * in ARM ELF files: $a, $t and $d.
2054 */
2055 static inline int is_arm_mapping_symbol(const char *str)
2056 {
2057 return str[0] == '$' && strchr("atd", str[1])
2058 && (str[2] == '\0' || str[2] == '.');
2059 }
2060
2061 static const char *get_ksymbol(struct module *mod,
2062 unsigned long addr,
2063 unsigned long *size,
2064 unsigned long *offset)
2065 {
2066 unsigned int i, best = 0;
2067 unsigned long nextval;
2068
2069 /* At worse, next value is at end of module */
2070 if (within(addr, mod->module_init, mod->init_size))
2071 nextval = (unsigned long)mod->module_init+mod->init_text_size;
2072 else
2073 nextval = (unsigned long)mod->module_core+mod->core_text_size;
2074
2075 /* Scan for closest preceeding symbol, and next symbol. (ELF
2076 starts real symbols at 1). */
2077 for (i = 1; i < mod->num_symtab; i++) {
2078 if (mod->symtab[i].st_shndx == SHN_UNDEF)
2079 continue;
2080
2081 /* We ignore unnamed symbols: they're uninformative
2082 * and inserted at a whim. */
2083 if (mod->symtab[i].st_value <= addr
2084 && mod->symtab[i].st_value > mod->symtab[best].st_value
2085 && *(mod->strtab + mod->symtab[i].st_name) != '\0'
2086 && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
2087 best = i;
2088 if (mod->symtab[i].st_value > addr
2089 && mod->symtab[i].st_value < nextval
2090 && *(mod->strtab + mod->symtab[i].st_name) != '\0'
2091 && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
2092 nextval = mod->symtab[i].st_value;
2093 }
2094
2095 if (!best)
2096 return NULL;
2097
2098 if (size)
2099 *size = nextval - mod->symtab[best].st_value;
2100 if (offset)
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 int lookup_module_symbol_name(unsigned long addr, char *symname)
2127 {
2128 struct module *mod;
2129
2130 mutex_lock(&module_mutex);
2131 list_for_each_entry(mod, &modules, list) {
2132 if (within(addr, mod->module_init, mod->init_size) ||
2133 within(addr, mod->module_core, mod->core_size)) {
2134 const char *sym;
2135
2136 sym = get_ksymbol(mod, addr, NULL, NULL);
2137 if (!sym)
2138 goto out;
2139 strlcpy(symname, sym, KSYM_NAME_LEN + 1);
2140 mutex_unlock(&module_mutex);
2141 return 0;
2142 }
2143 }
2144 out:
2145 mutex_unlock(&module_mutex);
2146 return -ERANGE;
2147 }
2148
2149 int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
2150 unsigned long *offset, char *modname, char *name)
2151 {
2152 struct module *mod;
2153
2154 mutex_lock(&module_mutex);
2155 list_for_each_entry(mod, &modules, list) {
2156 if (within(addr, mod->module_init, mod->init_size) ||
2157 within(addr, mod->module_core, mod->core_size)) {
2158 const char *sym;
2159
2160 sym = get_ksymbol(mod, addr, size, offset);
2161 if (!sym)
2162 goto out;
2163 if (modname)
2164 strlcpy(modname, mod->name, MODULE_NAME_LEN + 1);
2165 if (name)
2166 strlcpy(name, sym, KSYM_NAME_LEN + 1);
2167 mutex_unlock(&module_mutex);
2168 return 0;
2169 }
2170 }
2171 out:
2172 mutex_unlock(&module_mutex);
2173 return -ERANGE;
2174 }
2175
2176 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
2177 char *name, char *module_name, int *exported)
2178 {
2179 struct module *mod;
2180
2181 mutex_lock(&module_mutex);
2182 list_for_each_entry(mod, &modules, list) {
2183 if (symnum < mod->num_symtab) {
2184 *value = mod->symtab[symnum].st_value;
2185 *type = mod->symtab[symnum].st_info;
2186 strlcpy(name, mod->strtab + mod->symtab[symnum].st_name,
2187 KSYM_NAME_LEN + 1);
2188 strlcpy(module_name, mod->name, MODULE_NAME_LEN + 1);
2189 *exported = is_exported(name, mod);
2190 mutex_unlock(&module_mutex);
2191 return 0;
2192 }
2193 symnum -= mod->num_symtab;
2194 }
2195 mutex_unlock(&module_mutex);
2196 return -ERANGE;
2197 }
2198
2199 static unsigned long mod_find_symname(struct module *mod, const char *name)
2200 {
2201 unsigned int i;
2202
2203 for (i = 0; i < mod->num_symtab; i++)
2204 if (strcmp(name, mod->strtab+mod->symtab[i].st_name) == 0 &&
2205 mod->symtab[i].st_info != 'U')
2206 return mod->symtab[i].st_value;
2207 return 0;
2208 }
2209
2210 /* Look for this name: can be of form module:name. */
2211 unsigned long module_kallsyms_lookup_name(const char *name)
2212 {
2213 struct module *mod;
2214 char *colon;
2215 unsigned long ret = 0;
2216
2217 /* Don't lock: we're in enough trouble already. */
2218 if ((colon = strchr(name, ':')) != NULL) {
2219 *colon = '\0';
2220 if ((mod = find_module(name)) != NULL)
2221 ret = mod_find_symname(mod, colon+1);
2222 *colon = ':';
2223 } else {
2224 list_for_each_entry(mod, &modules, list)
2225 if ((ret = mod_find_symname(mod, name)) != 0)
2226 break;
2227 }
2228 return ret;
2229 }
2230 #endif /* CONFIG_KALLSYMS */
2231
2232 /* Called by the /proc file system to return a list of modules. */
2233 static void *m_start(struct seq_file *m, loff_t *pos)
2234 {
2235 mutex_lock(&module_mutex);
2236 return seq_list_start(&modules, *pos);
2237 }
2238
2239 static void *m_next(struct seq_file *m, void *p, loff_t *pos)
2240 {
2241 return seq_list_next(p, &modules, pos);
2242 }
2243
2244 static void m_stop(struct seq_file *m, void *p)
2245 {
2246 mutex_unlock(&module_mutex);
2247 }
2248
2249 static char *taint_flags(unsigned int taints, char *buf)
2250 {
2251 int bx = 0;
2252
2253 if (taints) {
2254 buf[bx++] = '(';
2255 if (taints & TAINT_PROPRIETARY_MODULE)
2256 buf[bx++] = 'P';
2257 if (taints & TAINT_FORCED_MODULE)
2258 buf[bx++] = 'F';
2259 /*
2260 * TAINT_FORCED_RMMOD: could be added.
2261 * TAINT_UNSAFE_SMP, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't
2262 * apply to modules.
2263 */
2264 buf[bx++] = ')';
2265 }
2266 buf[bx] = '\0';
2267
2268 return buf;
2269 }
2270
2271 static int m_show(struct seq_file *m, void *p)
2272 {
2273 struct module *mod = list_entry(p, struct module, list);
2274 char buf[8];
2275
2276 seq_printf(m, "%s %lu",
2277 mod->name, mod->init_size + mod->core_size);
2278 print_unload_info(m, mod);
2279
2280 /* Informative for users. */
2281 seq_printf(m, " %s",
2282 mod->state == MODULE_STATE_GOING ? "Unloading":
2283 mod->state == MODULE_STATE_COMING ? "Loading":
2284 "Live");
2285 /* Used by oprofile and other similar tools. */
2286 seq_printf(m, " 0x%p", mod->module_core);
2287
2288 /* Taints info */
2289 if (mod->taints)
2290 seq_printf(m, " %s", taint_flags(mod->taints, buf));
2291
2292 seq_printf(m, "\n");
2293 return 0;
2294 }
2295
2296 /* Format: modulename size refcount deps address
2297
2298 Where refcount is a number or -, and deps is a comma-separated list
2299 of depends or -.
2300 */
2301 const struct seq_operations modules_op = {
2302 .start = m_start,
2303 .next = m_next,
2304 .stop = m_stop,
2305 .show = m_show
2306 };
2307
2308 /* Given an address, look for it in the module exception tables. */
2309 const struct exception_table_entry *search_module_extables(unsigned long addr)
2310 {
2311 unsigned long flags;
2312 const struct exception_table_entry *e = NULL;
2313 struct module *mod;
2314
2315 spin_lock_irqsave(&modlist_lock, flags);
2316 list_for_each_entry(mod, &modules, list) {
2317 if (mod->num_exentries == 0)
2318 continue;
2319
2320 e = search_extable(mod->extable,
2321 mod->extable + mod->num_exentries - 1,
2322 addr);
2323 if (e)
2324 break;
2325 }
2326 spin_unlock_irqrestore(&modlist_lock, flags);
2327
2328 /* Now, if we found one, we are running inside it now, hence
2329 we cannot unload the module, hence no refcnt needed. */
2330 return e;
2331 }
2332
2333 /*
2334 * Is this a valid module address?
2335 */
2336 int is_module_address(unsigned long addr)
2337 {
2338 unsigned long flags;
2339 struct module *mod;
2340
2341 spin_lock_irqsave(&modlist_lock, flags);
2342
2343 list_for_each_entry(mod, &modules, list) {
2344 if (within(addr, mod->module_core, mod->core_size)) {
2345 spin_unlock_irqrestore(&modlist_lock, flags);
2346 return 1;
2347 }
2348 }
2349
2350 spin_unlock_irqrestore(&modlist_lock, flags);
2351
2352 return 0;
2353 }
2354
2355
2356 /* Is this a valid kernel address? We don't grab the lock: we are oopsing. */
2357 struct module *__module_text_address(unsigned long addr)
2358 {
2359 struct module *mod;
2360
2361 list_for_each_entry(mod, &modules, list)
2362 if (within(addr, mod->module_init, mod->init_text_size)
2363 || within(addr, mod->module_core, mod->core_text_size))
2364 return mod;
2365 return NULL;
2366 }
2367
2368 struct module *module_text_address(unsigned long addr)
2369 {
2370 struct module *mod;
2371 unsigned long flags;
2372
2373 spin_lock_irqsave(&modlist_lock, flags);
2374 mod = __module_text_address(addr);
2375 spin_unlock_irqrestore(&modlist_lock, flags);
2376
2377 return mod;
2378 }
2379
2380 /* Don't grab lock, we're oopsing. */
2381 void print_modules(void)
2382 {
2383 struct module *mod;
2384 char buf[8];
2385
2386 printk("Modules linked in:");
2387 list_for_each_entry(mod, &modules, list)
2388 printk(" %s%s", mod->name, taint_flags(mod->taints, buf));
2389 printk("\n");
2390 }
2391
2392 #ifdef CONFIG_SYSFS
2393 static char *make_driver_name(struct device_driver *drv)
2394 {
2395 char *driver_name;
2396
2397 driver_name = kmalloc(strlen(drv->name) + strlen(drv->bus->name) + 2,
2398 GFP_KERNEL);
2399 if (!driver_name)
2400 return NULL;
2401
2402 sprintf(driver_name, "%s:%s", drv->bus->name, drv->name);
2403 return driver_name;
2404 }
2405
2406 static void module_create_drivers_dir(struct module_kobject *mk)
2407 {
2408 if (!mk || mk->drivers_dir)
2409 return;
2410
2411 mk->drivers_dir = kobject_add_dir(&mk->kobj, "drivers");
2412 }
2413
2414 void module_add_driver(struct module *mod, struct device_driver *drv)
2415 {
2416 char *driver_name;
2417 int no_warn;
2418 struct module_kobject *mk = NULL;
2419
2420 if (!drv)
2421 return;
2422
2423 if (mod)
2424 mk = &mod->mkobj;
2425 else if (drv->mod_name) {
2426 struct kobject *mkobj;
2427
2428 /* Lookup built-in module entry in /sys/modules */
2429 mkobj = kset_find_obj(&module_subsys, drv->mod_name);
2430 if (mkobj) {
2431 mk = container_of(mkobj, struct module_kobject, kobj);
2432 /* remember our module structure */
2433 drv->mkobj = mk;
2434 /* kset_find_obj took a reference */
2435 kobject_put(mkobj);
2436 }
2437 }
2438
2439 if (!mk)
2440 return;
2441
2442 /* Don't check return codes; these calls are idempotent */
2443 no_warn = sysfs_create_link(&drv->kobj, &mk->kobj, "module");
2444 driver_name = make_driver_name(drv);
2445 if (driver_name) {
2446 module_create_drivers_dir(mk);
2447 no_warn = sysfs_create_link(mk->drivers_dir, &drv->kobj,
2448 driver_name);
2449 kfree(driver_name);
2450 }
2451 }
2452 EXPORT_SYMBOL(module_add_driver);
2453
2454 void module_remove_driver(struct device_driver *drv)
2455 {
2456 struct module_kobject *mk = NULL;
2457 char *driver_name;
2458
2459 if (!drv)
2460 return;
2461
2462 sysfs_remove_link(&drv->kobj, "module");
2463
2464 if (drv->owner)
2465 mk = &drv->owner->mkobj;
2466 else if (drv->mkobj)
2467 mk = drv->mkobj;
2468 if (mk && mk->drivers_dir) {
2469 driver_name = make_driver_name(drv);
2470 if (driver_name) {
2471 sysfs_remove_link(mk->drivers_dir, driver_name);
2472 kfree(driver_name);
2473 }
2474 }
2475 }
2476 EXPORT_SYMBOL(module_remove_driver);
2477 #endif
2478
2479 #ifdef CONFIG_MODVERSIONS
2480 /* Generate the signature for struct module here, too, for modversions. */
2481 void struct_module(struct module *mod) { return; }
2482 EXPORT_SYMBOL(struct_module);
2483 #endif
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