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mm/vmstat.c: cleanups
[wrt350n-kernel.git] / kernel / module.c
blobdb0ead0363e2504be6760e73cbef5a2b981a8565
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 /* List of modules, protected by module_mutex or preempt_disable
65 * (add/delete uses stop_machine). */
66 static DEFINE_MUTEX(module_mutex);
67 static LIST_HEAD(modules);
68
69 static BLOCKING_NOTIFIER_HEAD(module_notify_list);
70
71 int register_module_notifier(struct notifier_block * nb)
72 {
73 return blocking_notifier_chain_register(&module_notify_list, nb);
74 }
75 EXPORT_SYMBOL(register_module_notifier);
76
77 int unregister_module_notifier(struct notifier_block * nb)
78 {
79 return blocking_notifier_chain_unregister(&module_notify_list, nb);
80 }
81 EXPORT_SYMBOL(unregister_module_notifier);
82
83 /* We require a truly strong try_module_get() */
84 static inline int strong_try_module_get(struct module *mod)
85 {
86 if (mod && mod->state == MODULE_STATE_COMING)
87 return 0;
88 return try_module_get(mod);
89 }
90
91 static inline void add_taint_module(struct module *mod, unsigned flag)
92 {
93 add_taint(flag);
94 mod->taints |= flag;
95 }
96
97 /*
98 * A thread that wants to hold a reference to a module only while it
99 * is running can call this to safely exit. nfsd and lockd use this.
100 */
101 void __module_put_and_exit(struct module *mod, long code)
102 {
103 module_put(mod);
104 do_exit(code);
105 }
106 EXPORT_SYMBOL(__module_put_and_exit);
107
108 /* Find a module section: 0 means not found. */
109 static unsigned int find_sec(Elf_Ehdr *hdr,
110 Elf_Shdr *sechdrs,
111 const char *secstrings,
112 const char *name)
113 {
114 unsigned int i;
115
116 for (i = 1; i < hdr->e_shnum; i++)
117 /* Alloc bit cleared means "ignore it." */
118 if ((sechdrs[i].sh_flags & SHF_ALLOC)
119 && strcmp(secstrings+sechdrs[i].sh_name, name) == 0)
120 return i;
121 return 0;
122 }
123
124 /* Provided by the linker */
125 extern const struct kernel_symbol __start___ksymtab[];
126 extern const struct kernel_symbol __stop___ksymtab[];
127 extern const struct kernel_symbol __start___ksymtab_gpl[];
128 extern const struct kernel_symbol __stop___ksymtab_gpl[];
129 extern const struct kernel_symbol __start___ksymtab_gpl_future[];
130 extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
131 extern const struct kernel_symbol __start___ksymtab_unused[];
132 extern const struct kernel_symbol __stop___ksymtab_unused[];
133 extern const struct kernel_symbol __start___ksymtab_unused_gpl[];
134 extern const struct kernel_symbol __stop___ksymtab_unused_gpl[];
135 extern const struct kernel_symbol __start___ksymtab_gpl_future[];
136 extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
137 extern const unsigned long __start___kcrctab[];
138 extern const unsigned long __start___kcrctab_gpl[];
139 extern const unsigned long __start___kcrctab_gpl_future[];
140 extern const unsigned long __start___kcrctab_unused[];
141 extern const unsigned long __start___kcrctab_unused_gpl[];
142
143 #ifndef CONFIG_MODVERSIONS
144 #define symversion(base, idx) NULL
145 #else
146 #define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
147 #endif
148
149 /* lookup symbol in given range of kernel_symbols */
150 static const struct kernel_symbol *lookup_symbol(const char *name,
151 const struct kernel_symbol *start,
152 const struct kernel_symbol *stop)
153 {
154 const struct kernel_symbol *ks = start;
155 for (; ks < stop; ks++)
156 if (strcmp(ks->name, name) == 0)
157 return ks;
158 return NULL;
159 }
160
161 static void printk_unused_warning(const char *name)
162 {
163 printk(KERN_WARNING "Symbol %s is marked as UNUSED, "
164 "however this module is using it.\n", name);
165 printk(KERN_WARNING "This symbol will go away in the future.\n");
166 printk(KERN_WARNING "Please evalute if this is the right api to use, "
167 "and if it really is, submit a report the linux kernel "
168 "mailinglist together with submitting your code for "
169 "inclusion.\n");
170 }
171
172 /* Find a symbol, return value, crc and module which owns it */
173 static unsigned long __find_symbol(const char *name,
174 struct module **owner,
175 const unsigned long **crc,
176 int gplok)
177 {
178 struct module *mod;
179 const struct kernel_symbol *ks;
180
181 /* Core kernel first. */
182 *owner = NULL;
183 ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
184 if (ks) {
185 *crc = symversion(__start___kcrctab, (ks - __start___ksymtab));
186 return ks->value;
187 }
188 if (gplok) {
189 ks = lookup_symbol(name, __start___ksymtab_gpl,
190 __stop___ksymtab_gpl);
191 if (ks) {
192 *crc = symversion(__start___kcrctab_gpl,
193 (ks - __start___ksymtab_gpl));
194 return ks->value;
195 }
196 }
197 ks = lookup_symbol(name, __start___ksymtab_gpl_future,
198 __stop___ksymtab_gpl_future);
199 if (ks) {
200 if (!gplok) {
201 printk(KERN_WARNING "Symbol %s is being used "
202 "by a non-GPL module, which will not "
203 "be allowed in the future\n", name);
204 printk(KERN_WARNING "Please see the file "
205 "Documentation/feature-removal-schedule.txt "
206 "in the kernel source tree for more "
207 "details.\n");
208 }
209 *crc = symversion(__start___kcrctab_gpl_future,
210 (ks - __start___ksymtab_gpl_future));
211 return ks->value;
212 }
213
214 ks = lookup_symbol(name, __start___ksymtab_unused,
215 __stop___ksymtab_unused);
216 if (ks) {
217 printk_unused_warning(name);
218 *crc = symversion(__start___kcrctab_unused,
219 (ks - __start___ksymtab_unused));
220 return ks->value;
221 }
222
223 if (gplok)
224 ks = lookup_symbol(name, __start___ksymtab_unused_gpl,
225 __stop___ksymtab_unused_gpl);
226 if (ks) {
227 printk_unused_warning(name);
228 *crc = symversion(__start___kcrctab_unused_gpl,
229 (ks - __start___ksymtab_unused_gpl));
230 return ks->value;
231 }
232
233 /* Now try modules. */
234 list_for_each_entry(mod, &modules, list) {
235 *owner = mod;
236 ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
237 if (ks) {
238 *crc = symversion(mod->crcs, (ks - mod->syms));
239 return ks->value;
240 }
241
242 if (gplok) {
243 ks = lookup_symbol(name, mod->gpl_syms,
244 mod->gpl_syms + mod->num_gpl_syms);
245 if (ks) {
246 *crc = symversion(mod->gpl_crcs,
247 (ks - mod->gpl_syms));
248 return ks->value;
249 }
250 }
251 ks = lookup_symbol(name, mod->unused_syms, mod->unused_syms + mod->num_unused_syms);
252 if (ks) {
253 printk_unused_warning(name);
254 *crc = symversion(mod->unused_crcs, (ks - mod->unused_syms));
255 return ks->value;
256 }
257
258 if (gplok) {
259 ks = lookup_symbol(name, mod->unused_gpl_syms,
260 mod->unused_gpl_syms + mod->num_unused_gpl_syms);
261 if (ks) {
262 printk_unused_warning(name);
263 *crc = symversion(mod->unused_gpl_crcs,
264 (ks - mod->unused_gpl_syms));
265 return ks->value;
266 }
267 }
268 ks = lookup_symbol(name, mod->gpl_future_syms,
269 (mod->gpl_future_syms +
270 mod->num_gpl_future_syms));
271 if (ks) {
272 if (!gplok) {
273 printk(KERN_WARNING "Symbol %s is being used "
274 "by a non-GPL module, which will not "
275 "be allowed in the future\n", name);
276 printk(KERN_WARNING "Please see the file "
277 "Documentation/feature-removal-schedule.txt "
278 "in the kernel source tree for more "
279 "details.\n");
280 }
281 *crc = symversion(mod->gpl_future_crcs,
282 (ks - mod->gpl_future_syms));
283 return ks->value;
284 }
285 }
286 DEBUGP("Failed to find symbol %s\n", name);
287 return 0;
288 }
289
290 /* Search for module by name: must hold module_mutex. */
291 static struct module *find_module(const char *name)
292 {
293 struct module *mod;
294
295 list_for_each_entry(mod, &modules, list) {
296 if (strcmp(mod->name, name) == 0)
297 return mod;
298 }
299 return NULL;
300 }
301
302 #ifdef CONFIG_SMP
303 /* Number of blocks used and allocated. */
304 static unsigned int pcpu_num_used, pcpu_num_allocated;
305 /* Size of each block. -ve means used. */
306 static int *pcpu_size;
307
308 static int split_block(unsigned int i, unsigned short size)
309 {
310 /* Reallocation required? */
311 if (pcpu_num_used + 1 > pcpu_num_allocated) {
312 int *new;
313
314 new = krealloc(pcpu_size, sizeof(new[0])*pcpu_num_allocated*2,
315 GFP_KERNEL);
316 if (!new)
317 return 0;
318
319 pcpu_num_allocated *= 2;
320 pcpu_size = new;
321 }
322
323 /* Insert a new subblock */
324 memmove(&pcpu_size[i+1], &pcpu_size[i],
325 sizeof(pcpu_size[0]) * (pcpu_num_used - i));
326 pcpu_num_used++;
327
328 pcpu_size[i+1] -= size;
329 pcpu_size[i] = size;
330 return 1;
331 }
332
333 static inline unsigned int block_size(int val)
334 {
335 if (val < 0)
336 return -val;
337 return val;
338 }
339
340 /* Created by linker magic */
341 extern char __per_cpu_start[], __per_cpu_end[];
342
343 static void *percpu_modalloc(unsigned long size, unsigned long align,
344 const char *name)
345 {
346 unsigned long extra;
347 unsigned int i;
348 void *ptr;
349
350 if (align > PAGE_SIZE) {
351 printk(KERN_WARNING "%s: per-cpu alignment %li > %li\n",
352 name, align, PAGE_SIZE);
353 align = PAGE_SIZE;
354 }
355
356 ptr = __per_cpu_start;
357 for (i = 0; i < pcpu_num_used; ptr += block_size(pcpu_size[i]), i++) {
358 /* Extra for alignment requirement. */
359 extra = ALIGN((unsigned long)ptr, align) - (unsigned long)ptr;
360 BUG_ON(i == 0 && extra != 0);
361
362 if (pcpu_size[i] < 0 || pcpu_size[i] < extra + size)
363 continue;
364
365 /* Transfer extra to previous block. */
366 if (pcpu_size[i-1] < 0)
367 pcpu_size[i-1] -= extra;
368 else
369 pcpu_size[i-1] += extra;
370 pcpu_size[i] -= extra;
371 ptr += extra;
372
373 /* Split block if warranted */
374 if (pcpu_size[i] - size > sizeof(unsigned long))
375 if (!split_block(i, size))
376 return NULL;
377
378 /* Mark allocated */
379 pcpu_size[i] = -pcpu_size[i];
380 return ptr;
381 }
382
383 printk(KERN_WARNING "Could not allocate %lu bytes percpu data\n",
384 size);
385 return NULL;
386 }
387
388 static void percpu_modfree(void *freeme)
389 {
390 unsigned int i;
391 void *ptr = __per_cpu_start + block_size(pcpu_size[0]);
392
393 /* First entry is core kernel percpu data. */
394 for (i = 1; i < pcpu_num_used; ptr += block_size(pcpu_size[i]), i++) {
395 if (ptr == freeme) {
396 pcpu_size[i] = -pcpu_size[i];
397 goto free;
398 }
399 }
400 BUG();
401
402 free:
403 /* Merge with previous? */
404 if (pcpu_size[i-1] >= 0) {
405 pcpu_size[i-1] += pcpu_size[i];
406 pcpu_num_used--;
407 memmove(&pcpu_size[i], &pcpu_size[i+1],
408 (pcpu_num_used - i) * sizeof(pcpu_size[0]));
409 i--;
410 }
411 /* Merge with next? */
412 if (i+1 < pcpu_num_used && pcpu_size[i+1] >= 0) {
413 pcpu_size[i] += pcpu_size[i+1];
414 pcpu_num_used--;
415 memmove(&pcpu_size[i+1], &pcpu_size[i+2],
416 (pcpu_num_used - (i+1)) * sizeof(pcpu_size[0]));
417 }
418 }
419
420 static unsigned int find_pcpusec(Elf_Ehdr *hdr,
421 Elf_Shdr *sechdrs,
422 const char *secstrings)
423 {
424 return find_sec(hdr, sechdrs, secstrings, ".data.percpu");
425 }
426
427 static int percpu_modinit(void)
428 {
429 pcpu_num_used = 2;
430 pcpu_num_allocated = 2;
431 pcpu_size = kmalloc(sizeof(pcpu_size[0]) * pcpu_num_allocated,
432 GFP_KERNEL);
433 /* Static in-kernel percpu data (used). */
434 pcpu_size[0] = -(__per_cpu_end-__per_cpu_start);
435 /* Free room. */
436 pcpu_size[1] = PERCPU_ENOUGH_ROOM + pcpu_size[0];
437 if (pcpu_size[1] < 0) {
438 printk(KERN_ERR "No per-cpu room for modules.\n");
439 pcpu_num_used = 1;
440 }
441
442 return 0;
443 }
444 __initcall(percpu_modinit);
445 #else /* ... !CONFIG_SMP */
446 static inline void *percpu_modalloc(unsigned long size, unsigned long align,
447 const char *name)
448 {
449 return NULL;
450 }
451 static inline void percpu_modfree(void *pcpuptr)
452 {
453 BUG();
454 }
455 static inline unsigned int find_pcpusec(Elf_Ehdr *hdr,
456 Elf_Shdr *sechdrs,
457 const char *secstrings)
458 {
459 return 0;
460 }
461 static inline void percpu_modcopy(void *pcpudst, const void *src,
462 unsigned long size)
463 {
464 /* pcpusec should be 0, and size of that section should be 0. */
465 BUG_ON(size != 0);
466 }
467 #endif /* CONFIG_SMP */
468
469 #define MODINFO_ATTR(field) \
470 static void setup_modinfo_##field(struct module *mod, const char *s) \
471 { \
472 mod->field = kstrdup(s, GFP_KERNEL); \
473 } \
474 static ssize_t show_modinfo_##field(struct module_attribute *mattr, \
475 struct module *mod, char *buffer) \
476 { \
477 return sprintf(buffer, "%s\n", mod->field); \
478 } \
479 static int modinfo_##field##_exists(struct module *mod) \
480 { \
481 return mod->field != NULL; \
482 } \
483 static void free_modinfo_##field(struct module *mod) \
484 { \
485 kfree(mod->field); \
486 mod->field = NULL; \
487 } \
488 static struct module_attribute modinfo_##field = { \
489 .attr = { .name = __stringify(field), .mode = 0444 }, \
490 .show = show_modinfo_##field, \
491 .setup = setup_modinfo_##field, \
492 .test = modinfo_##field##_exists, \
493 .free = free_modinfo_##field, \
494 };
495
496 MODINFO_ATTR(version);
497 MODINFO_ATTR(srcversion);
498
499 #ifdef CONFIG_MODULE_UNLOAD
500 /* Init the unload section of the module. */
501 static void module_unload_init(struct module *mod)
502 {
503 unsigned int i;
504
505 INIT_LIST_HEAD(&mod->modules_which_use_me);
506 for (i = 0; i < NR_CPUS; i++)
507 local_set(&mod->ref[i].count, 0);
508 /* Hold reference count during initialization. */
509 local_set(&mod->ref[raw_smp_processor_id()].count, 1);
510 /* Backwards compatibility macros put refcount during init. */
511 mod->waiter = current;
512 }
513
514 /* modules using other modules */
515 struct module_use
516 {
517 struct list_head list;
518 struct module *module_which_uses;
519 };
520
521 /* Does a already use b? */
522 static int already_uses(struct module *a, struct module *b)
523 {
524 struct module_use *use;
525
526 list_for_each_entry(use, &b->modules_which_use_me, list) {
527 if (use->module_which_uses == a) {
528 DEBUGP("%s uses %s!\n", a->name, b->name);
529 return 1;
530 }
531 }
532 DEBUGP("%s does not use %s!\n", a->name, b->name);
533 return 0;
534 }
535
536 /* Module a uses b */
537 static int use_module(struct module *a, struct module *b)
538 {
539 struct module_use *use;
540 int no_warn;
541
542 if (b == NULL || already_uses(a, b)) return 1;
543
544 if (!strong_try_module_get(b))
545 return 0;
546
547 DEBUGP("Allocating new usage for %s.\n", a->name);
548 use = kmalloc(sizeof(*use), GFP_ATOMIC);
549 if (!use) {
550 printk("%s: out of memory loading\n", a->name);
551 module_put(b);
552 return 0;
553 }
554
555 use->module_which_uses = a;
556 list_add(&use->list, &b->modules_which_use_me);
557 no_warn = sysfs_create_link(b->holders_dir, &a->mkobj.kobj, a->name);
558 return 1;
559 }
560
561 /* Clear the unload stuff of the module. */
562 static void module_unload_free(struct module *mod)
563 {
564 struct module *i;
565
566 list_for_each_entry(i, &modules, list) {
567 struct module_use *use;
568
569 list_for_each_entry(use, &i->modules_which_use_me, list) {
570 if (use->module_which_uses == mod) {
571 DEBUGP("%s unusing %s\n", mod->name, i->name);
572 module_put(i);
573 list_del(&use->list);
574 kfree(use);
575 sysfs_remove_link(i->holders_dir, mod->name);
576 /* There can be at most one match. */
577 break;
578 }
579 }
580 }
581 }
582
583 #ifdef CONFIG_MODULE_FORCE_UNLOAD
584 static inline int try_force_unload(unsigned int flags)
585 {
586 int ret = (flags & O_TRUNC);
587 if (ret)
588 add_taint(TAINT_FORCED_RMMOD);
589 return ret;
590 }
591 #else
592 static inline int try_force_unload(unsigned int flags)
593 {
594 return 0;
595 }
596 #endif /* CONFIG_MODULE_FORCE_UNLOAD */
597
598 struct stopref
599 {
600 struct module *mod;
601 int flags;
602 int *forced;
603 };
604
605 /* Whole machine is stopped with interrupts off when this runs. */
606 static int __try_stop_module(void *_sref)
607 {
608 struct stopref *sref = _sref;
609
610 /* If it's not unused, quit unless we are told to block. */
611 if ((sref->flags & O_NONBLOCK) && module_refcount(sref->mod) != 0) {
612 if (!(*sref->forced = try_force_unload(sref->flags)))
613 return -EWOULDBLOCK;
614 }
615
616 /* Mark it as dying. */
617 sref->mod->state = MODULE_STATE_GOING;
618 return 0;
619 }
620
621 static int try_stop_module(struct module *mod, int flags, int *forced)
622 {
623 struct stopref sref = { mod, flags, forced };
624
625 return stop_machine_run(__try_stop_module, &sref, NR_CPUS);
626 }
627
628 unsigned int module_refcount(struct module *mod)
629 {
630 unsigned int i, total = 0;
631
632 for (i = 0; i < NR_CPUS; i++)
633 total += local_read(&mod->ref[i].count);
634 return total;
635 }
636 EXPORT_SYMBOL(module_refcount);
637
638 /* This exists whether we can unload or not */
639 static void free_module(struct module *mod);
640
641 static void wait_for_zero_refcount(struct module *mod)
642 {
643 /* Since we might sleep for some time, drop the semaphore first */
644 mutex_unlock(&module_mutex);
645 for (;;) {
646 DEBUGP("Looking at refcount...\n");
647 set_current_state(TASK_UNINTERRUPTIBLE);
648 if (module_refcount(mod) == 0)
649 break;
650 schedule();
651 }
652 current->state = TASK_RUNNING;
653 mutex_lock(&module_mutex);
654 }
655
656 asmlinkage long
657 sys_delete_module(const char __user *name_user, unsigned int flags)
658 {
659 struct module *mod;
660 char name[MODULE_NAME_LEN];
661 int ret, forced = 0;
662
663 if (!capable(CAP_SYS_MODULE))
664 return -EPERM;
665
666 if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
667 return -EFAULT;
668 name[MODULE_NAME_LEN-1] = '\0';
669
670 if (mutex_lock_interruptible(&module_mutex) != 0)
671 return -EINTR;
672
673 mod = find_module(name);
674 if (!mod) {
675 ret = -ENOENT;
676 goto out;
677 }
678
679 if (!list_empty(&mod->modules_which_use_me)) {
680 /* Other modules depend on us: get rid of them first. */
681 ret = -EWOULDBLOCK;
682 goto out;
683 }
684
685 /* Doing init or already dying? */
686 if (mod->state != MODULE_STATE_LIVE) {
687 /* FIXME: if (force), slam module count and wake up
688 waiter --RR */
689 DEBUGP("%s already dying\n", mod->name);
690 ret = -EBUSY;
691 goto out;
692 }
693
694 /* If it has an init func, it must have an exit func to unload */
695 if ((mod->init != NULL && mod->exit == NULL)
696 || mod->unsafe) {
697 forced = try_force_unload(flags);
698 if (!forced) {
699 /* This module can't be removed */
700 ret = -EBUSY;
701 goto out;
702 }
703 }
704
705 /* Set this up before setting mod->state */
706 mod->waiter = current;
707
708 /* Stop the machine so refcounts can't move and disable module. */
709 ret = try_stop_module(mod, flags, &forced);
710 if (ret != 0)
711 goto out;
712
713 /* Never wait if forced. */
714 if (!forced && module_refcount(mod) != 0)
715 wait_for_zero_refcount(mod);
716
717 /* Final destruction now noone is using it. */
718 if (mod->exit != NULL) {
719 mutex_unlock(&module_mutex);
720 mod->exit();
721 mutex_lock(&module_mutex);
722 }
723 free_module(mod);
724
725 out:
726 mutex_unlock(&module_mutex);
727 return ret;
728 }
729
730 static void print_unload_info(struct seq_file *m, struct module *mod)
731 {
732 struct module_use *use;
733 int printed_something = 0;
734
735 seq_printf(m, " %u ", module_refcount(mod));
736
737 /* Always include a trailing , so userspace can differentiate
738 between this and the old multi-field proc format. */
739 list_for_each_entry(use, &mod->modules_which_use_me, list) {
740 printed_something = 1;
741 seq_printf(m, "%s,", use->module_which_uses->name);
742 }
743
744 if (mod->unsafe) {
745 printed_something = 1;
746 seq_printf(m, "[unsafe],");
747 }
748
749 if (mod->init != NULL && mod->exit == NULL) {
750 printed_something = 1;
751 seq_printf(m, "[permanent],");
752 }
753
754 if (!printed_something)
755 seq_printf(m, "-");
756 }
757
758 void __symbol_put(const char *symbol)
759 {
760 struct module *owner;
761 const unsigned long *crc;
762
763 preempt_disable();
764 if (!__find_symbol(symbol, &owner, &crc, 1))
765 BUG();
766 module_put(owner);
767 preempt_enable();
768 }
769 EXPORT_SYMBOL(__symbol_put);
770
771 void symbol_put_addr(void *addr)
772 {
773 struct module *modaddr;
774
775 if (core_kernel_text((unsigned long)addr))
776 return;
777
778 if (!(modaddr = module_text_address((unsigned long)addr)))
779 BUG();
780 module_put(modaddr);
781 }
782 EXPORT_SYMBOL_GPL(symbol_put_addr);
783
784 static ssize_t show_refcnt(struct module_attribute *mattr,
785 struct module *mod, char *buffer)
786 {
787 return sprintf(buffer, "%u\n", module_refcount(mod));
788 }
789
790 static struct module_attribute refcnt = {
791 .attr = { .name = "refcnt", .mode = 0444 },
792 .show = show_refcnt,
793 };
794
795 void module_put(struct module *module)
796 {
797 if (module) {
798 unsigned int cpu = get_cpu();
799 local_dec(&module->ref[cpu].count);
800 /* Maybe they're waiting for us to drop reference? */
801 if (unlikely(!module_is_live(module)))
802 wake_up_process(module->waiter);
803 put_cpu();
804 }
805 }
806 EXPORT_SYMBOL(module_put);
807
808 #else /* !CONFIG_MODULE_UNLOAD */
809 static void print_unload_info(struct seq_file *m, struct module *mod)
810 {
811 /* We don't know the usage count, or what modules are using. */
812 seq_printf(m, " - -");
813 }
814
815 static inline void module_unload_free(struct module *mod)
816 {
817 }
818
819 static inline int use_module(struct module *a, struct module *b)
820 {
821 return strong_try_module_get(b);
822 }
823
824 static inline void module_unload_init(struct module *mod)
825 {
826 }
827 #endif /* CONFIG_MODULE_UNLOAD */
828
829 static ssize_t show_initstate(struct module_attribute *mattr,
830 struct module *mod, char *buffer)
831 {
832 const char *state = "unknown";
833
834 switch (mod->state) {
835 case MODULE_STATE_LIVE:
836 state = "live";
837 break;
838 case MODULE_STATE_COMING:
839 state = "coming";
840 break;
841 case MODULE_STATE_GOING:
842 state = "going";
843 break;
844 }
845 return sprintf(buffer, "%s\n", state);
846 }
847
848 static struct module_attribute initstate = {
849 .attr = { .name = "initstate", .mode = 0444 },
850 .show = show_initstate,
851 };
852
853 static struct module_attribute *modinfo_attrs[] = {
854 &modinfo_version,
855 &modinfo_srcversion,
856 &initstate,
857 #ifdef CONFIG_MODULE_UNLOAD
858 &refcnt,
859 #endif
860 NULL,
861 };
862
863 static const char vermagic[] = VERMAGIC_STRING;
864
865 #ifdef CONFIG_MODVERSIONS
866 static int check_version(Elf_Shdr *sechdrs,
867 unsigned int versindex,
868 const char *symname,
869 struct module *mod,
870 const unsigned long *crc)
871 {
872 unsigned int i, num_versions;
873 struct modversion_info *versions;
874
875 /* Exporting module didn't supply crcs? OK, we're already tainted. */
876 if (!crc)
877 return 1;
878
879 versions = (void *) sechdrs[versindex].sh_addr;
880 num_versions = sechdrs[versindex].sh_size
881 / sizeof(struct modversion_info);
882
883 for (i = 0; i < num_versions; i++) {
884 if (strcmp(versions[i].name, symname) != 0)
885 continue;
886
887 if (versions[i].crc == *crc)
888 return 1;
889 printk("%s: disagrees about version of symbol %s\n",
890 mod->name, symname);
891 DEBUGP("Found checksum %lX vs module %lX\n",
892 *crc, versions[i].crc);
893 return 0;
894 }
895 /* Not in module's version table. OK, but that taints the kernel. */
896 if (!(tainted & TAINT_FORCED_MODULE))
897 printk("%s: no version for \"%s\" found: kernel tainted.\n",
898 mod->name, symname);
899 add_taint_module(mod, TAINT_FORCED_MODULE);
900 return 1;
901 }
902
903 static inline int check_modstruct_version(Elf_Shdr *sechdrs,
904 unsigned int versindex,
905 struct module *mod)
906 {
907 const unsigned long *crc;
908 struct module *owner;
909
910 if (!__find_symbol("struct_module", &owner, &crc, 1))
911 BUG();
912 return check_version(sechdrs, versindex, "struct_module", mod,
913 crc);
914 }
915
916 /* First part is kernel version, which we ignore. */
917 static inline int same_magic(const char *amagic, const char *bmagic)
918 {
919 amagic += strcspn(amagic, " ");
920 bmagic += strcspn(bmagic, " ");
921 return strcmp(amagic, bmagic) == 0;
922 }
923 #else
924 static inline int check_version(Elf_Shdr *sechdrs,
925 unsigned int versindex,
926 const char *symname,
927 struct module *mod,
928 const unsigned long *crc)
929 {
930 return 1;
931 }
932
933 static inline int check_modstruct_version(Elf_Shdr *sechdrs,
934 unsigned int versindex,
935 struct module *mod)
936 {
937 return 1;
938 }
939
940 static inline int same_magic(const char *amagic, const char *bmagic)
941 {
942 return strcmp(amagic, bmagic) == 0;
943 }
944 #endif /* CONFIG_MODVERSIONS */
945
946 /* Resolve a symbol for this module. I.e. if we find one, record usage.
947 Must be holding module_mutex. */
948 static unsigned long resolve_symbol(Elf_Shdr *sechdrs,
949 unsigned int versindex,
950 const char *name,
951 struct module *mod)
952 {
953 struct module *owner;
954 unsigned long ret;
955 const unsigned long *crc;
956
957 ret = __find_symbol(name, &owner, &crc,
958 !(mod->taints & TAINT_PROPRIETARY_MODULE));
959 if (ret) {
960 /* use_module can fail due to OOM, or module unloading */
961 if (!check_version(sechdrs, versindex, name, mod, crc) ||
962 !use_module(mod, owner))
963 ret = 0;
964 }
965 return ret;
966 }
967
968
969 /*
970 * /sys/module/foo/sections stuff
971 * J. Corbet <corbet@lwn.net>
972 */
973 #ifdef CONFIG_KALLSYMS
974 static ssize_t module_sect_show(struct module_attribute *mattr,
975 struct module *mod, char *buf)
976 {
977 struct module_sect_attr *sattr =
978 container_of(mattr, struct module_sect_attr, mattr);
979 return sprintf(buf, "0x%lx\n", sattr->address);
980 }
981
982 static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
983 {
984 int section;
985
986 for (section = 0; section < sect_attrs->nsections; section++)
987 kfree(sect_attrs->attrs[section].name);
988 kfree(sect_attrs);
989 }
990
991 static void add_sect_attrs(struct module *mod, unsigned int nsect,
992 char *secstrings, Elf_Shdr *sechdrs)
993 {
994 unsigned int nloaded = 0, i, size[2];
995 struct module_sect_attrs *sect_attrs;
996 struct module_sect_attr *sattr;
997 struct attribute **gattr;
998
999 /* Count loaded sections and allocate structures */
1000 for (i = 0; i < nsect; i++)
1001 if (sechdrs[i].sh_flags & SHF_ALLOC)
1002 nloaded++;
1003 size[0] = ALIGN(sizeof(*sect_attrs)
1004 + nloaded * sizeof(sect_attrs->attrs[0]),
1005 sizeof(sect_attrs->grp.attrs[0]));
1006 size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]);
1007 sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
1008 if (sect_attrs == NULL)
1009 return;
1010
1011 /* Setup section attributes. */
1012 sect_attrs->grp.name = "sections";
1013 sect_attrs->grp.attrs = (void *)sect_attrs + size[0];
1014
1015 sect_attrs->nsections = 0;
1016 sattr = &sect_attrs->attrs[0];
1017 gattr = &sect_attrs->grp.attrs[0];
1018 for (i = 0; i < nsect; i++) {
1019 if (! (sechdrs[i].sh_flags & SHF_ALLOC))
1020 continue;
1021 sattr->address = sechdrs[i].sh_addr;
1022 sattr->name = kstrdup(secstrings + sechdrs[i].sh_name,
1023 GFP_KERNEL);
1024 if (sattr->name == NULL)
1025 goto out;
1026 sect_attrs->nsections++;
1027 sattr->mattr.show = module_sect_show;
1028 sattr->mattr.store = NULL;
1029 sattr->mattr.attr.name = sattr->name;
1030 sattr->mattr.attr.mode = S_IRUGO;
1031 *(gattr++) = &(sattr++)->mattr.attr;
1032 }
1033 *gattr = NULL;
1034
1035 if (sysfs_create_group(&mod->mkobj.kobj, &sect_attrs->grp))
1036 goto out;
1037
1038 mod->sect_attrs = sect_attrs;
1039 return;
1040 out:
1041 free_sect_attrs(sect_attrs);
1042 }
1043
1044 static void remove_sect_attrs(struct module *mod)
1045 {
1046 if (mod->sect_attrs) {
1047 sysfs_remove_group(&mod->mkobj.kobj,
1048 &mod->sect_attrs->grp);
1049 /* We are positive that no one is using any sect attrs
1050 * at this point. Deallocate immediately. */
1051 free_sect_attrs(mod->sect_attrs);
1052 mod->sect_attrs = NULL;
1053 }
1054 }
1055
1056 #else
1057
1058 static inline void add_sect_attrs(struct module *mod, unsigned int nsect,
1059 char *sectstrings, Elf_Shdr *sechdrs)
1060 {
1061 }
1062
1063 static inline void remove_sect_attrs(struct module *mod)
1064 {
1065 }
1066 #endif /* CONFIG_KALLSYMS */
1067
1068 #ifdef CONFIG_SYSFS
1069 int module_add_modinfo_attrs(struct module *mod)
1070 {
1071 struct module_attribute *attr;
1072 struct module_attribute *temp_attr;
1073 int error = 0;
1074 int i;
1075
1076 mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
1077 (ARRAY_SIZE(modinfo_attrs) + 1)),
1078 GFP_KERNEL);
1079 if (!mod->modinfo_attrs)
1080 return -ENOMEM;
1081
1082 temp_attr = mod->modinfo_attrs;
1083 for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
1084 if (!attr->test ||
1085 (attr->test && attr->test(mod))) {
1086 memcpy(temp_attr, attr, sizeof(*temp_attr));
1087 error = sysfs_create_file(&mod->mkobj.kobj,&temp_attr->attr);
1088 ++temp_attr;
1089 }
1090 }
1091 return error;
1092 }
1093
1094 void module_remove_modinfo_attrs(struct module *mod)
1095 {
1096 struct module_attribute *attr;
1097 int i;
1098
1099 for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
1100 /* pick a field to test for end of list */
1101 if (!attr->attr.name)
1102 break;
1103 sysfs_remove_file(&mod->mkobj.kobj,&attr->attr);
1104 if (attr->free)
1105 attr->free(mod);
1106 }
1107 kfree(mod->modinfo_attrs);
1108 }
1109 #endif
1110
1111 #ifdef CONFIG_SYSFS
1112 int mod_sysfs_init(struct module *mod)
1113 {
1114 int err;
1115
1116 if (!module_sysfs_initialized) {
1117 printk(KERN_ERR "%s: module sysfs not initialized\n",
1118 mod->name);
1119 err = -EINVAL;
1120 goto out;
1121 }
1122 memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
1123 err = kobject_set_name(&mod->mkobj.kobj, "%s", mod->name);
1124 if (err)
1125 goto out;
1126 kobj_set_kset_s(&mod->mkobj, module_subsys);
1127 mod->mkobj.mod = mod;
1128
1129 kobject_init(&mod->mkobj.kobj);
1130
1131 out:
1132 return err;
1133 }
1134
1135 int mod_sysfs_setup(struct module *mod,
1136 struct kernel_param *kparam,
1137 unsigned int num_params)
1138 {
1139 int err;
1140
1141 /* delay uevent until full sysfs population */
1142 err = kobject_add(&mod->mkobj.kobj);
1143 if (err)
1144 goto out;
1145
1146 mod->holders_dir = kobject_add_dir(&mod->mkobj.kobj, "holders");
1147 if (!mod->holders_dir) {
1148 err = -ENOMEM;
1149 goto out_unreg;
1150 }
1151
1152 err = module_param_sysfs_setup(mod, kparam, num_params);
1153 if (err)
1154 goto out_unreg_holders;
1155
1156 err = module_add_modinfo_attrs(mod);
1157 if (err)
1158 goto out_unreg_param;
1159
1160 kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
1161 return 0;
1162
1163 out_unreg_param:
1164 module_param_sysfs_remove(mod);
1165 out_unreg_holders:
1166 kobject_unregister(mod->holders_dir);
1167 out_unreg:
1168 kobject_del(&mod->mkobj.kobj);
1169 kobject_put(&mod->mkobj.kobj);
1170 out:
1171 return err;
1172 }
1173 #endif
1174
1175 static void mod_kobject_remove(struct module *mod)
1176 {
1177 module_remove_modinfo_attrs(mod);
1178 module_param_sysfs_remove(mod);
1179 kobject_unregister(mod->mkobj.drivers_dir);
1180 kobject_unregister(mod->holders_dir);
1181 kobject_unregister(&mod->mkobj.kobj);
1182 }
1183
1184 /*
1185 * unlink the module with the whole machine is stopped with interrupts off
1186 * - this defends against kallsyms not taking locks
1187 */
1188 static int __unlink_module(void *_mod)
1189 {
1190 struct module *mod = _mod;
1191 list_del(&mod->list);
1192 return 0;
1193 }
1194
1195 /* Free a module, remove from lists, etc (must hold module_mutex). */
1196 static void free_module(struct module *mod)
1197 {
1198 /* Delete from various lists */
1199 stop_machine_run(__unlink_module, mod, NR_CPUS);
1200 remove_sect_attrs(mod);
1201 mod_kobject_remove(mod);
1202
1203 unwind_remove_table(mod->unwind_info, 0);
1204
1205 /* Arch-specific cleanup. */
1206 module_arch_cleanup(mod);
1207
1208 /* Module unload stuff */
1209 module_unload_free(mod);
1210
1211 /* This may be NULL, but that's OK */
1212 module_free(mod, mod->module_init);
1213 kfree(mod->args);
1214 if (mod->percpu)
1215 percpu_modfree(mod->percpu);
1216
1217 /* Free lock-classes: */
1218 lockdep_free_key_range(mod->module_core, mod->core_size);
1219
1220 /* Finally, free the core (containing the module structure) */
1221 module_free(mod, mod->module_core);
1222 }
1223
1224 void *__symbol_get(const char *symbol)
1225 {
1226 struct module *owner;
1227 unsigned long value;
1228 const unsigned long *crc;
1229
1230 preempt_disable();
1231 value = __find_symbol(symbol, &owner, &crc, 1);
1232 if (value && !strong_try_module_get(owner))
1233 value = 0;
1234 preempt_enable();
1235
1236 return (void *)value;
1237 }
1238 EXPORT_SYMBOL_GPL(__symbol_get);
1239
1240 /*
1241 * Ensure that an exported symbol [global namespace] does not already exist
1242 * in the kernel or in some other module's exported symbol table.
1243 */
1244 static int verify_export_symbols(struct module *mod)
1245 {
1246 const char *name = NULL;
1247 unsigned long i, ret = 0;
1248 struct module *owner;
1249 const unsigned long *crc;
1250
1251 for (i = 0; i < mod->num_syms; i++)
1252 if (__find_symbol(mod->syms[i].name, &owner, &crc, 1)) {
1253 name = mod->syms[i].name;
1254 ret = -ENOEXEC;
1255 goto dup;
1256 }
1257
1258 for (i = 0; i < mod->num_gpl_syms; i++)
1259 if (__find_symbol(mod->gpl_syms[i].name, &owner, &crc, 1)) {
1260 name = mod->gpl_syms[i].name;
1261 ret = -ENOEXEC;
1262 goto dup;
1263 }
1264
1265 dup:
1266 if (ret)
1267 printk(KERN_ERR "%s: exports duplicate symbol %s (owned by %s)\n",
1268 mod->name, name, module_name(owner));
1269
1270 return ret;
1271 }
1272
1273 /* Change all symbols so that sh_value encodes the pointer directly. */
1274 static int simplify_symbols(Elf_Shdr *sechdrs,
1275 unsigned int symindex,
1276 const char *strtab,
1277 unsigned int versindex,
1278 unsigned int pcpuindex,
1279 struct module *mod)
1280 {
1281 Elf_Sym *sym = (void *)sechdrs[symindex].sh_addr;
1282 unsigned long secbase;
1283 unsigned int i, n = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
1284 int ret = 0;
1285
1286 for (i = 1; i < n; i++) {
1287 switch (sym[i].st_shndx) {
1288 case SHN_COMMON:
1289 /* We compiled with -fno-common. These are not
1290 supposed to happen. */
1291 DEBUGP("Common symbol: %s\n", strtab + sym[i].st_name);
1292 printk("%s: please compile with -fno-common\n",
1293 mod->name);
1294 ret = -ENOEXEC;
1295 break;
1296
1297 case SHN_ABS:
1298 /* Don't need to do anything */
1299 DEBUGP("Absolute symbol: 0x%08lx\n",
1300 (long)sym[i].st_value);
1301 break;
1302
1303 case SHN_UNDEF:
1304 sym[i].st_value
1305 = resolve_symbol(sechdrs, versindex,
1306 strtab + sym[i].st_name, mod);
1307
1308 /* Ok if resolved. */
1309 if (sym[i].st_value != 0)
1310 break;
1311 /* Ok if weak. */
1312 if (ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
1313 break;
1314
1315 printk(KERN_WARNING "%s: Unknown symbol %s\n",
1316 mod->name, strtab + sym[i].st_name);
1317 ret = -ENOENT;
1318 break;
1319
1320 default:
1321 /* Divert to percpu allocation if a percpu var. */
1322 if (sym[i].st_shndx == pcpuindex)
1323 secbase = (unsigned long)mod->percpu;
1324 else
1325 secbase = sechdrs[sym[i].st_shndx].sh_addr;
1326 sym[i].st_value += secbase;
1327 break;
1328 }
1329 }
1330
1331 return ret;
1332 }
1333
1334 /* Update size with this section: return offset. */
1335 static long get_offset(unsigned long *size, Elf_Shdr *sechdr)
1336 {
1337 long ret;
1338
1339 ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
1340 *size = ret + sechdr->sh_size;
1341 return ret;
1342 }
1343
1344 /* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
1345 might -- code, read-only data, read-write data, small data. Tally
1346 sizes, and place the offsets into sh_entsize fields: high bit means it
1347 belongs in init. */
1348 static void layout_sections(struct module *mod,
1349 const Elf_Ehdr *hdr,
1350 Elf_Shdr *sechdrs,
1351 const char *secstrings)
1352 {
1353 static unsigned long const masks[][2] = {
1354 /* NOTE: all executable code must be the first section
1355 * in this array; otherwise modify the text_size
1356 * finder in the two loops below */
1357 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
1358 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
1359 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
1360 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
1361 };
1362 unsigned int m, i;
1363
1364 for (i = 0; i < hdr->e_shnum; i++)
1365 sechdrs[i].sh_entsize = ~0UL;
1366
1367 DEBUGP("Core section allocation order:\n");
1368 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
1369 for (i = 0; i < hdr->e_shnum; ++i) {
1370 Elf_Shdr *s = &sechdrs[i];
1371
1372 if ((s->sh_flags & masks[m][0]) != masks[m][0]
1373 || (s->sh_flags & masks[m][1])
1374 || s->sh_entsize != ~0UL
1375 || strncmp(secstrings + s->sh_name,
1376 ".init", 5) == 0)
1377 continue;
1378 s->sh_entsize = get_offset(&mod->core_size, s);
1379 DEBUGP("\t%s\n", secstrings + s->sh_name);
1380 }
1381 if (m == 0)
1382 mod->core_text_size = mod->core_size;
1383 }
1384
1385 DEBUGP("Init section allocation order:\n");
1386 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
1387 for (i = 0; i < hdr->e_shnum; ++i) {
1388 Elf_Shdr *s = &sechdrs[i];
1389
1390 if ((s->sh_flags & masks[m][0]) != masks[m][0]
1391 || (s->sh_flags & masks[m][1])
1392 || s->sh_entsize != ~0UL
1393 || strncmp(secstrings + s->sh_name,
1394 ".init", 5) != 0)
1395 continue;
1396 s->sh_entsize = (get_offset(&mod->init_size, s)
1397 | INIT_OFFSET_MASK);
1398 DEBUGP("\t%s\n", secstrings + s->sh_name);
1399 }
1400 if (m == 0)
1401 mod->init_text_size = mod->init_size;
1402 }
1403 }
1404
1405 static void set_license(struct module *mod, const char *license)
1406 {
1407 if (!license)
1408 license = "unspecified";
1409
1410 if (!license_is_gpl_compatible(license)) {
1411 if (!(tainted & TAINT_PROPRIETARY_MODULE))
1412 printk(KERN_WARNING "%s: module license '%s' taints "
1413 "kernel.\n", mod->name, license);
1414 add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
1415 }
1416 }
1417
1418 /* Parse tag=value strings from .modinfo section */
1419 static char *next_string(char *string, unsigned long *secsize)
1420 {
1421 /* Skip non-zero chars */
1422 while (string[0]) {
1423 string++;
1424 if ((*secsize)-- <= 1)
1425 return NULL;
1426 }
1427
1428 /* Skip any zero padding. */
1429 while (!string[0]) {
1430 string++;
1431 if ((*secsize)-- <= 1)
1432 return NULL;
1433 }
1434 return string;
1435 }
1436
1437 static char *get_modinfo(Elf_Shdr *sechdrs,
1438 unsigned int info,
1439 const char *tag)
1440 {
1441 char *p;
1442 unsigned int taglen = strlen(tag);
1443 unsigned long size = sechdrs[info].sh_size;
1444
1445 for (p = (char *)sechdrs[info].sh_addr; p; p = next_string(p, &size)) {
1446 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
1447 return p + taglen + 1;
1448 }
1449 return NULL;
1450 }
1451
1452 static void setup_modinfo(struct module *mod, Elf_Shdr *sechdrs,
1453 unsigned int infoindex)
1454 {
1455 struct module_attribute *attr;
1456 int i;
1457
1458 for (i = 0; (attr = modinfo_attrs[i]); i++) {
1459 if (attr->setup)
1460 attr->setup(mod,
1461 get_modinfo(sechdrs,
1462 infoindex,
1463 attr->attr.name));
1464 }
1465 }
1466
1467 #ifdef CONFIG_KALLSYMS
1468 static int is_exported(const char *name, const struct module *mod)
1469 {
1470 if (!mod && lookup_symbol(name, __start___ksymtab, __stop___ksymtab))
1471 return 1;
1472 else
1473 if (mod && lookup_symbol(name, mod->syms, mod->syms + mod->num_syms))
1474 return 1;
1475 else
1476 return 0;
1477 }
1478
1479 /* As per nm */
1480 static char elf_type(const Elf_Sym *sym,
1481 Elf_Shdr *sechdrs,
1482 const char *secstrings,
1483 struct module *mod)
1484 {
1485 if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
1486 if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
1487 return 'v';
1488 else
1489 return 'w';
1490 }
1491 if (sym->st_shndx == SHN_UNDEF)
1492 return 'U';
1493 if (sym->st_shndx == SHN_ABS)
1494 return 'a';
1495 if (sym->st_shndx >= SHN_LORESERVE)
1496 return '?';
1497 if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
1498 return 't';
1499 if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
1500 && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
1501 if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
1502 return 'r';
1503 else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
1504 return 'g';
1505 else
1506 return 'd';
1507 }
1508 if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
1509 if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
1510 return 's';
1511 else
1512 return 'b';
1513 }
1514 if (strncmp(secstrings + sechdrs[sym->st_shndx].sh_name,
1515 ".debug", strlen(".debug")) == 0)
1516 return 'n';
1517 return '?';
1518 }
1519
1520 static void add_kallsyms(struct module *mod,
1521 Elf_Shdr *sechdrs,
1522 unsigned int symindex,
1523 unsigned int strindex,
1524 const char *secstrings)
1525 {
1526 unsigned int i;
1527
1528 mod->symtab = (void *)sechdrs[symindex].sh_addr;
1529 mod->num_symtab = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
1530 mod->strtab = (void *)sechdrs[strindex].sh_addr;
1531
1532 /* Set types up while we still have access to sections. */
1533 for (i = 0; i < mod->num_symtab; i++)
1534 mod->symtab[i].st_info
1535 = elf_type(&mod->symtab[i], sechdrs, secstrings, mod);
1536 }
1537 #else
1538 static inline void add_kallsyms(struct module *mod,
1539 Elf_Shdr *sechdrs,
1540 unsigned int symindex,
1541 unsigned int strindex,
1542 const char *secstrings)
1543 {
1544 }
1545 #endif /* CONFIG_KALLSYMS */
1546
1547 /* Allocate and load the module: note that size of section 0 is always
1548 zero, and we rely on this for optional sections. */
1549 static struct module *load_module(void __user *umod,
1550 unsigned long len,
1551 const char __user *uargs)
1552 {
1553 Elf_Ehdr *hdr;
1554 Elf_Shdr *sechdrs;
1555 char *secstrings, *args, *modmagic, *strtab = NULL;
1556 unsigned int i;
1557 unsigned int symindex = 0;
1558 unsigned int strindex = 0;
1559 unsigned int setupindex;
1560 unsigned int exindex;
1561 unsigned int exportindex;
1562 unsigned int modindex;
1563 unsigned int obsparmindex;
1564 unsigned int infoindex;
1565 unsigned int gplindex;
1566 unsigned int crcindex;
1567 unsigned int gplcrcindex;
1568 unsigned int versindex;
1569 unsigned int pcpuindex;
1570 unsigned int gplfutureindex;
1571 unsigned int gplfuturecrcindex;
1572 unsigned int unwindex = 0;
1573 unsigned int unusedindex;
1574 unsigned int unusedcrcindex;
1575 unsigned int unusedgplindex;
1576 unsigned int unusedgplcrcindex;
1577 struct module *mod;
1578 long err = 0;
1579 void *percpu = NULL, *ptr = NULL; /* Stops spurious gcc warning */
1580 struct exception_table_entry *extable;
1581 mm_segment_t old_fs;
1582
1583 DEBUGP("load_module: umod=%p, len=%lu, uargs=%p\n",
1584 umod, len, uargs);
1585 if (len < sizeof(*hdr))
1586 return ERR_PTR(-ENOEXEC);
1587
1588 /* Suck in entire file: we'll want most of it. */
1589 /* vmalloc barfs on "unusual" numbers. Check here */
1590 if (len > 64 * 1024 * 1024 || (hdr = vmalloc(len)) == NULL)
1591 return ERR_PTR(-ENOMEM);
1592 if (copy_from_user(hdr, umod, len) != 0) {
1593 err = -EFAULT;
1594 goto free_hdr;
1595 }
1596
1597 /* Sanity checks against insmoding binaries or wrong arch,
1598 weird elf version */
1599 if (memcmp(hdr->e_ident, ELFMAG, 4) != 0
1600 || hdr->e_type != ET_REL
1601 || !elf_check_arch(hdr)
1602 || hdr->e_shentsize != sizeof(*sechdrs)) {
1603 err = -ENOEXEC;
1604 goto free_hdr;
1605 }
1606
1607 if (len < hdr->e_shoff + hdr->e_shnum * sizeof(Elf_Shdr))
1608 goto truncated;
1609
1610 /* Convenience variables */
1611 sechdrs = (void *)hdr + hdr->e_shoff;
1612 secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
1613 sechdrs[0].sh_addr = 0;
1614
1615 for (i = 1; i < hdr->e_shnum; i++) {
1616 if (sechdrs[i].sh_type != SHT_NOBITS
1617 && len < sechdrs[i].sh_offset + sechdrs[i].sh_size)
1618 goto truncated;
1619
1620 /* Mark all sections sh_addr with their address in the
1621 temporary image. */
1622 sechdrs[i].sh_addr = (size_t)hdr + sechdrs[i].sh_offset;
1623
1624 /* Internal symbols and strings. */
1625 if (sechdrs[i].sh_type == SHT_SYMTAB) {
1626 symindex = i;
1627 strindex = sechdrs[i].sh_link;
1628 strtab = (char *)hdr + sechdrs[strindex].sh_offset;
1629 }
1630 #ifndef CONFIG_MODULE_UNLOAD
1631 /* Don't load .exit sections */
1632 if (strncmp(secstrings+sechdrs[i].sh_name, ".exit", 5) == 0)
1633 sechdrs[i].sh_flags &= ~(unsigned long)SHF_ALLOC;
1634 #endif
1635 }
1636
1637 modindex = find_sec(hdr, sechdrs, secstrings,
1638 ".gnu.linkonce.this_module");
1639 if (!modindex) {
1640 printk(KERN_WARNING "No module found in object\n");
1641 err = -ENOEXEC;
1642 goto free_hdr;
1643 }
1644 mod = (void *)sechdrs[modindex].sh_addr;
1645
1646 if (symindex == 0) {
1647 printk(KERN_WARNING "%s: module has no symbols (stripped?)\n",
1648 mod->name);
1649 err = -ENOEXEC;
1650 goto free_hdr;
1651 }
1652
1653 /* Optional sections */
1654 exportindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab");
1655 gplindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_gpl");
1656 gplfutureindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_gpl_future");
1657 unusedindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_unused");
1658 unusedgplindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_unused_gpl");
1659 crcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab");
1660 gplcrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_gpl");
1661 gplfuturecrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_gpl_future");
1662 unusedcrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_unused");
1663 unusedgplcrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_unused_gpl");
1664 setupindex = find_sec(hdr, sechdrs, secstrings, "__param");
1665 exindex = find_sec(hdr, sechdrs, secstrings, "__ex_table");
1666 obsparmindex = find_sec(hdr, sechdrs, secstrings, "__obsparm");
1667 versindex = find_sec(hdr, sechdrs, secstrings, "__versions");
1668 infoindex = find_sec(hdr, sechdrs, secstrings, ".modinfo");
1669 pcpuindex = find_pcpusec(hdr, sechdrs, secstrings);
1670 #ifdef ARCH_UNWIND_SECTION_NAME
1671 unwindex = find_sec(hdr, sechdrs, secstrings, ARCH_UNWIND_SECTION_NAME);
1672 #endif
1673
1674 /* Don't keep modinfo section */
1675 sechdrs[infoindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
1676 #ifdef CONFIG_KALLSYMS
1677 /* Keep symbol and string tables for decoding later. */
1678 sechdrs[symindex].sh_flags |= SHF_ALLOC;
1679 sechdrs[strindex].sh_flags |= SHF_ALLOC;
1680 #endif
1681 if (unwindex)
1682 sechdrs[unwindex].sh_flags |= SHF_ALLOC;
1683
1684 /* Check module struct version now, before we try to use module. */
1685 if (!check_modstruct_version(sechdrs, versindex, mod)) {
1686 err = -ENOEXEC;
1687 goto free_hdr;
1688 }
1689
1690 modmagic = get_modinfo(sechdrs, infoindex, "vermagic");
1691 /* This is allowed: modprobe --force will invalidate it. */
1692 if (!modmagic) {
1693 add_taint_module(mod, TAINT_FORCED_MODULE);
1694 printk(KERN_WARNING "%s: no version magic, tainting kernel.\n",
1695 mod->name);
1696 } else if (!same_magic(modmagic, vermagic)) {
1697 printk(KERN_ERR "%s: version magic '%s' should be '%s'\n",
1698 mod->name, modmagic, vermagic);
1699 err = -ENOEXEC;
1700 goto free_hdr;
1701 }
1702
1703 /* Now copy in args */
1704 args = strndup_user(uargs, ~0UL >> 1);
1705 if (IS_ERR(args)) {
1706 err = PTR_ERR(args);
1707 goto free_hdr;
1708 }
1709
1710 if (find_module(mod->name)) {
1711 err = -EEXIST;
1712 goto free_mod;
1713 }
1714
1715 mod->state = MODULE_STATE_COMING;
1716
1717 /* Allow arches to frob section contents and sizes. */
1718 err = module_frob_arch_sections(hdr, sechdrs, secstrings, mod);
1719 if (err < 0)
1720 goto free_mod;
1721
1722 if (pcpuindex) {
1723 /* We have a special allocation for this section. */
1724 percpu = percpu_modalloc(sechdrs[pcpuindex].sh_size,
1725 sechdrs[pcpuindex].sh_addralign,
1726 mod->name);
1727 if (!percpu) {
1728 err = -ENOMEM;
1729 goto free_mod;
1730 }
1731 sechdrs[pcpuindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
1732 mod->percpu = percpu;
1733 }
1734
1735 /* Determine total sizes, and put offsets in sh_entsize. For now
1736 this is done generically; there doesn't appear to be any
1737 special cases for the architectures. */
1738 layout_sections(mod, hdr, sechdrs, secstrings);
1739
1740 /* Do the allocs. */
1741 ptr = module_alloc(mod->core_size);
1742 if (!ptr) {
1743 err = -ENOMEM;
1744 goto free_percpu;
1745 }
1746 memset(ptr, 0, mod->core_size);
1747 mod->module_core = ptr;
1748
1749 ptr = module_alloc(mod->init_size);
1750 if (!ptr && mod->init_size) {
1751 err = -ENOMEM;
1752 goto free_core;
1753 }
1754 memset(ptr, 0, mod->init_size);
1755 mod->module_init = ptr;
1756
1757 /* Transfer each section which specifies SHF_ALLOC */
1758 DEBUGP("final section addresses:\n");
1759 for (i = 0; i < hdr->e_shnum; i++) {
1760 void *dest;
1761
1762 if (!(sechdrs[i].sh_flags & SHF_ALLOC))
1763 continue;
1764
1765 if (sechdrs[i].sh_entsize & INIT_OFFSET_MASK)
1766 dest = mod->module_init
1767 + (sechdrs[i].sh_entsize & ~INIT_OFFSET_MASK);
1768 else
1769 dest = mod->module_core + sechdrs[i].sh_entsize;
1770
1771 if (sechdrs[i].sh_type != SHT_NOBITS)
1772 memcpy(dest, (void *)sechdrs[i].sh_addr,
1773 sechdrs[i].sh_size);
1774 /* Update sh_addr to point to copy in image. */
1775 sechdrs[i].sh_addr = (unsigned long)dest;
1776 DEBUGP("\t0x%lx %s\n", sechdrs[i].sh_addr, secstrings + sechdrs[i].sh_name);
1777 }
1778 /* Module has been moved. */
1779 mod = (void *)sechdrs[modindex].sh_addr;
1780
1781 /* Now we've moved module, initialize linked lists, etc. */
1782 module_unload_init(mod);
1783
1784 /* Initialize kobject, so we can reference it. */
1785 if (mod_sysfs_init(mod) != 0)
1786 goto cleanup;
1787
1788 /* Set up license info based on the info section */
1789 set_license(mod, get_modinfo(sechdrs, infoindex, "license"));
1790
1791 if (strcmp(mod->name, "ndiswrapper") == 0)
1792 add_taint(TAINT_PROPRIETARY_MODULE);
1793 if (strcmp(mod->name, "driverloader") == 0)
1794 add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
1795
1796 /* Set up MODINFO_ATTR fields */
1797 setup_modinfo(mod, sechdrs, infoindex);
1798
1799 /* Fix up syms, so that st_value is a pointer to location. */
1800 err = simplify_symbols(sechdrs, symindex, strtab, versindex, pcpuindex,
1801 mod);
1802 if (err < 0)
1803 goto cleanup;
1804
1805 /* Set up EXPORTed & EXPORT_GPLed symbols (section 0 is 0 length) */
1806 mod->num_syms = sechdrs[exportindex].sh_size / sizeof(*mod->syms);
1807 mod->syms = (void *)sechdrs[exportindex].sh_addr;
1808 if (crcindex)
1809 mod->crcs = (void *)sechdrs[crcindex].sh_addr;
1810 mod->num_gpl_syms = sechdrs[gplindex].sh_size / sizeof(*mod->gpl_syms);
1811 mod->gpl_syms = (void *)sechdrs[gplindex].sh_addr;
1812 if (gplcrcindex)
1813 mod->gpl_crcs = (void *)sechdrs[gplcrcindex].sh_addr;
1814 mod->num_gpl_future_syms = sechdrs[gplfutureindex].sh_size /
1815 sizeof(*mod->gpl_future_syms);
1816 mod->num_unused_syms = sechdrs[unusedindex].sh_size /
1817 sizeof(*mod->unused_syms);
1818 mod->num_unused_gpl_syms = sechdrs[unusedgplindex].sh_size /
1819 sizeof(*mod->unused_gpl_syms);
1820 mod->gpl_future_syms = (void *)sechdrs[gplfutureindex].sh_addr;
1821 if (gplfuturecrcindex)
1822 mod->gpl_future_crcs = (void *)sechdrs[gplfuturecrcindex].sh_addr;
1823
1824 mod->unused_syms = (void *)sechdrs[unusedindex].sh_addr;
1825 if (unusedcrcindex)
1826 mod->unused_crcs = (void *)sechdrs[unusedcrcindex].sh_addr;
1827 mod->unused_gpl_syms = (void *)sechdrs[unusedgplindex].sh_addr;
1828 if (unusedgplcrcindex)
1829 mod->unused_crcs = (void *)sechdrs[unusedgplcrcindex].sh_addr;
1830
1831 #ifdef CONFIG_MODVERSIONS
1832 if ((mod->num_syms && !crcindex) ||
1833 (mod->num_gpl_syms && !gplcrcindex) ||
1834 (mod->num_gpl_future_syms && !gplfuturecrcindex) ||
1835 (mod->num_unused_syms && !unusedcrcindex) ||
1836 (mod->num_unused_gpl_syms && !unusedgplcrcindex)) {
1837 printk(KERN_WARNING "%s: No versions for exported symbols."
1838 " Tainting kernel.\n", mod->name);
1839 add_taint_module(mod, TAINT_FORCED_MODULE);
1840 }
1841 #endif
1842
1843 /* Now do relocations. */
1844 for (i = 1; i < hdr->e_shnum; i++) {
1845 const char *strtab = (char *)sechdrs[strindex].sh_addr;
1846 unsigned int info = sechdrs[i].sh_info;
1847
1848 /* Not a valid relocation section? */
1849 if (info >= hdr->e_shnum)
1850 continue;
1851
1852 /* Don't bother with non-allocated sections */
1853 if (!(sechdrs[info].sh_flags & SHF_ALLOC))
1854 continue;
1855
1856 if (sechdrs[i].sh_type == SHT_REL)
1857 err = apply_relocate(sechdrs, strtab, symindex, i,mod);
1858 else if (sechdrs[i].sh_type == SHT_RELA)
1859 err = apply_relocate_add(sechdrs, strtab, symindex, i,
1860 mod);
1861 if (err < 0)
1862 goto cleanup;
1863 }
1864
1865 /* Find duplicate symbols */
1866 err = verify_export_symbols(mod);
1867
1868 if (err < 0)
1869 goto cleanup;
1870
1871 /* Set up and sort exception table */
1872 mod->num_exentries = sechdrs[exindex].sh_size / sizeof(*mod->extable);
1873 mod->extable = extable = (void *)sechdrs[exindex].sh_addr;
1874 sort_extable(extable, extable + mod->num_exentries);
1875
1876 /* Finally, copy percpu area over. */
1877 percpu_modcopy(mod->percpu, (void *)sechdrs[pcpuindex].sh_addr,
1878 sechdrs[pcpuindex].sh_size);
1879
1880 add_kallsyms(mod, sechdrs, symindex, strindex, secstrings);
1881
1882 err = module_finalize(hdr, sechdrs, mod);
1883 if (err < 0)
1884 goto cleanup;
1885
1886 /* flush the icache in correct context */
1887 old_fs = get_fs();
1888 set_fs(KERNEL_DS);
1889
1890 /*
1891 * Flush the instruction cache, since we've played with text.
1892 * Do it before processing of module parameters, so the module
1893 * can provide parameter accessor functions of its own.
1894 */
1895 if (mod->module_init)
1896 flush_icache_range((unsigned long)mod->module_init,
1897 (unsigned long)mod->module_init
1898 + mod->init_size);
1899 flush_icache_range((unsigned long)mod->module_core,
1900 (unsigned long)mod->module_core + mod->core_size);
1901
1902 set_fs(old_fs);
1903
1904 mod->args = args;
1905 if (obsparmindex)
1906 printk(KERN_WARNING "%s: Ignoring obsolete parameters\n",
1907 mod->name);
1908
1909 /* Size of section 0 is 0, so this works well if no params */
1910 err = parse_args(mod->name, mod->args,
1911 (struct kernel_param *)
1912 sechdrs[setupindex].sh_addr,
1913 sechdrs[setupindex].sh_size
1914 / sizeof(struct kernel_param),
1915 NULL);
1916 if (err < 0)
1917 goto arch_cleanup;
1918
1919 err = mod_sysfs_setup(mod,
1920 (struct kernel_param *)
1921 sechdrs[setupindex].sh_addr,
1922 sechdrs[setupindex].sh_size
1923 / sizeof(struct kernel_param));
1924 if (err < 0)
1925 goto arch_cleanup;
1926 add_sect_attrs(mod, hdr->e_shnum, secstrings, sechdrs);
1927
1928 /* Size of section 0 is 0, so this works well if no unwind info. */
1929 mod->unwind_info = unwind_add_table(mod,
1930 (void *)sechdrs[unwindex].sh_addr,
1931 sechdrs[unwindex].sh_size);
1932
1933 /* Get rid of temporary copy */
1934 vfree(hdr);
1935
1936 /* Done! */
1937 return mod;
1938
1939 arch_cleanup:
1940 module_arch_cleanup(mod);
1941 cleanup:
1942 module_unload_free(mod);
1943 module_free(mod, mod->module_init);
1944 free_core:
1945 module_free(mod, mod->module_core);
1946 free_percpu:
1947 if (percpu)
1948 percpu_modfree(percpu);
1949 free_mod:
1950 kfree(args);
1951 free_hdr:
1952 vfree(hdr);
1953 return ERR_PTR(err);
1954
1955 truncated:
1956 printk(KERN_ERR "Module len %lu truncated\n", len);
1957 err = -ENOEXEC;
1958 goto free_hdr;
1959 }
1960
1961 /*
1962 * link the module with the whole machine is stopped with interrupts off
1963 * - this defends against kallsyms not taking locks
1964 */
1965 static int __link_module(void *_mod)
1966 {
1967 struct module *mod = _mod;
1968 list_add(&mod->list, &modules);
1969 return 0;
1970 }
1971
1972 /* This is where the real work happens */
1973 asmlinkage long
1974 sys_init_module(void __user *umod,
1975 unsigned long len,
1976 const char __user *uargs)
1977 {
1978 struct module *mod;
1979 int ret = 0;
1980
1981 /* Must have permission */
1982 if (!capable(CAP_SYS_MODULE))
1983 return -EPERM;
1984
1985 /* Only one module load at a time, please */
1986 if (mutex_lock_interruptible(&module_mutex) != 0)
1987 return -EINTR;
1988
1989 /* Do all the hard work */
1990 mod = load_module(umod, len, uargs);
1991 if (IS_ERR(mod)) {
1992 mutex_unlock(&module_mutex);
1993 return PTR_ERR(mod);
1994 }
1995
1996 /* Now sew it into the lists. They won't access us, since
1997 strong_try_module_get() will fail. */
1998 stop_machine_run(__link_module, mod, NR_CPUS);
1999
2000 /* Drop lock so they can recurse */
2001 mutex_unlock(&module_mutex);
2002
2003 blocking_notifier_call_chain(&module_notify_list,
2004 MODULE_STATE_COMING, mod);
2005
2006 /* Start the module */
2007 if (mod->init != NULL)
2008 ret = mod->init();
2009 if (ret < 0) {
2010 /* Init routine failed: abort. Try to protect us from
2011 buggy refcounters. */
2012 mod->state = MODULE_STATE_GOING;
2013 synchronize_sched();
2014 if (mod->unsafe)
2015 printk(KERN_ERR "%s: module is now stuck!\n",
2016 mod->name);
2017 else {
2018 module_put(mod);
2019 mutex_lock(&module_mutex);
2020 free_module(mod);
2021 mutex_unlock(&module_mutex);
2022 }
2023 return ret;
2024 }
2025
2026 /* Now it's a first class citizen! */
2027 mutex_lock(&module_mutex);
2028 mod->state = MODULE_STATE_LIVE;
2029 /* Drop initial reference. */
2030 module_put(mod);
2031 unwind_remove_table(mod->unwind_info, 1);
2032 module_free(mod, mod->module_init);
2033 mod->module_init = NULL;
2034 mod->init_size = 0;
2035 mod->init_text_size = 0;
2036 mutex_unlock(&module_mutex);
2037
2038 return 0;
2039 }
2040
2041 static inline int within(unsigned long addr, void *start, unsigned long size)
2042 {
2043 return ((void *)addr >= start && (void *)addr < start + size);
2044 }
2045
2046 #ifdef CONFIG_KALLSYMS
2047 /*
2048 * This ignores the intensely annoying "mapping symbols" found
2049 * in ARM ELF files: $a, $t and $d.
2050 */
2051 static inline int is_arm_mapping_symbol(const char *str)
2052 {
2053 return str[0] == '$' && strchr("atd", str[1])
2054 && (str[2] == '\0' || str[2] == '.');
2055 }
2056
2057 static const char *get_ksymbol(struct module *mod,
2058 unsigned long addr,
2059 unsigned long *size,
2060 unsigned long *offset)
2061 {
2062 unsigned int i, best = 0;
2063 unsigned long nextval;
2064
2065 /* At worse, next value is at end of module */
2066 if (within(addr, mod->module_init, mod->init_size))
2067 nextval = (unsigned long)mod->module_init+mod->init_text_size;
2068 else
2069 nextval = (unsigned long)mod->module_core+mod->core_text_size;
2070
2071 /* Scan for closest preceeding symbol, and next symbol. (ELF
2072 starts real symbols at 1). */
2073 for (i = 1; i < mod->num_symtab; i++) {
2074 if (mod->symtab[i].st_shndx == SHN_UNDEF)
2075 continue;
2076
2077 /* We ignore unnamed symbols: they're uninformative
2078 * and inserted at a whim. */
2079 if (mod->symtab[i].st_value <= addr
2080 && mod->symtab[i].st_value > mod->symtab[best].st_value
2081 && *(mod->strtab + mod->symtab[i].st_name) != '\0'
2082 && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
2083 best = i;
2084 if (mod->symtab[i].st_value > addr
2085 && mod->symtab[i].st_value < nextval
2086 && *(mod->strtab + mod->symtab[i].st_name) != '\0'
2087 && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
2088 nextval = mod->symtab[i].st_value;
2089 }
2090
2091 if (!best)
2092 return NULL;
2093
2094 if (size)
2095 *size = nextval - mod->symtab[best].st_value;
2096 if (offset)
2097 *offset = addr - mod->symtab[best].st_value;
2098 return mod->strtab + mod->symtab[best].st_name;
2099 }
2100
2101 /* For kallsyms to ask for address resolution. NULL means not found.
2102 We don't lock, as this is used for oops resolution and races are a
2103 lesser concern. */
2104 const char *module_address_lookup(unsigned long addr,
2105 unsigned long *size,
2106 unsigned long *offset,
2107 char **modname)
2108 {
2109 struct module *mod;
2110
2111 list_for_each_entry(mod, &modules, list) {
2112 if (within(addr, mod->module_init, mod->init_size)
2113 || within(addr, mod->module_core, mod->core_size)) {
2114 if (modname)
2115 *modname = mod->name;
2116 return get_ksymbol(mod, addr, size, offset);
2117 }
2118 }
2119 return NULL;
2120 }
2121
2122 int lookup_module_symbol_name(unsigned long addr, char *symname)
2123 {
2124 struct module *mod;
2125
2126 mutex_lock(&module_mutex);
2127 list_for_each_entry(mod, &modules, list) {
2128 if (within(addr, mod->module_init, mod->init_size) ||
2129 within(addr, mod->module_core, mod->core_size)) {
2130 const char *sym;
2131
2132 sym = get_ksymbol(mod, addr, NULL, NULL);
2133 if (!sym)
2134 goto out;
2135 strlcpy(symname, sym, KSYM_NAME_LEN);
2136 mutex_unlock(&module_mutex);
2137 return 0;
2138 }
2139 }
2140 out:
2141 mutex_unlock(&module_mutex);
2142 return -ERANGE;
2143 }
2144
2145 int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
2146 unsigned long *offset, char *modname, char *name)
2147 {
2148 struct module *mod;
2149
2150 mutex_lock(&module_mutex);
2151 list_for_each_entry(mod, &modules, list) {
2152 if (within(addr, mod->module_init, mod->init_size) ||
2153 within(addr, mod->module_core, mod->core_size)) {
2154 const char *sym;
2155
2156 sym = get_ksymbol(mod, addr, size, offset);
2157 if (!sym)
2158 goto out;
2159 if (modname)
2160 strlcpy(modname, mod->name, MODULE_NAME_LEN);
2161 if (name)
2162 strlcpy(name, sym, KSYM_NAME_LEN);
2163 mutex_unlock(&module_mutex);
2164 return 0;
2165 }
2166 }
2167 out:
2168 mutex_unlock(&module_mutex);
2169 return -ERANGE;
2170 }
2171
2172 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
2173 char *name, char *module_name, int *exported)
2174 {
2175 struct module *mod;
2176
2177 mutex_lock(&module_mutex);
2178 list_for_each_entry(mod, &modules, list) {
2179 if (symnum < mod->num_symtab) {
2180 *value = mod->symtab[symnum].st_value;
2181 *type = mod->symtab[symnum].st_info;
2182 strlcpy(name, mod->strtab + mod->symtab[symnum].st_name,
2183 KSYM_NAME_LEN);
2184 strlcpy(module_name, mod->name, MODULE_NAME_LEN);
2185 *exported = is_exported(name, mod);
2186 mutex_unlock(&module_mutex);
2187 return 0;
2188 }
2189 symnum -= mod->num_symtab;
2190 }
2191 mutex_unlock(&module_mutex);
2192 return -ERANGE;
2193 }
2194
2195 static unsigned long mod_find_symname(struct module *mod, const char *name)
2196 {
2197 unsigned int i;
2198
2199 for (i = 0; i < mod->num_symtab; i++)
2200 if (strcmp(name, mod->strtab+mod->symtab[i].st_name) == 0 &&
2201 mod->symtab[i].st_info != 'U')
2202 return mod->symtab[i].st_value;
2203 return 0;
2204 }
2205
2206 /* Look for this name: can be of form module:name. */
2207 unsigned long module_kallsyms_lookup_name(const char *name)
2208 {
2209 struct module *mod;
2210 char *colon;
2211 unsigned long ret = 0;
2212
2213 /* Don't lock: we're in enough trouble already. */
2214 if ((colon = strchr(name, ':')) != NULL) {
2215 *colon = '\0';
2216 if ((mod = find_module(name)) != NULL)
2217 ret = mod_find_symname(mod, colon+1);
2218 *colon = ':';
2219 } else {
2220 list_for_each_entry(mod, &modules, list)
2221 if ((ret = mod_find_symname(mod, name)) != 0)
2222 break;
2223 }
2224 return ret;
2225 }
2226 #endif /* CONFIG_KALLSYMS */
2227
2228 /* Called by the /proc file system to return a list of modules. */
2229 static void *m_start(struct seq_file *m, loff_t *pos)
2230 {
2231 mutex_lock(&module_mutex);
2232 return seq_list_start(&modules, *pos);
2233 }
2234
2235 static void *m_next(struct seq_file *m, void *p, loff_t *pos)
2236 {
2237 return seq_list_next(p, &modules, pos);
2238 }
2239
2240 static void m_stop(struct seq_file *m, void *p)
2241 {
2242 mutex_unlock(&module_mutex);
2243 }
2244
2245 static char *taint_flags(unsigned int taints, char *buf)
2246 {
2247 int bx = 0;
2248
2249 if (taints) {
2250 buf[bx++] = '(';
2251 if (taints & TAINT_PROPRIETARY_MODULE)
2252 buf[bx++] = 'P';
2253 if (taints & TAINT_FORCED_MODULE)
2254 buf[bx++] = 'F';
2255 /*
2256 * TAINT_FORCED_RMMOD: could be added.
2257 * TAINT_UNSAFE_SMP, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't
2258 * apply to modules.
2259 */
2260 buf[bx++] = ')';
2261 }
2262 buf[bx] = '\0';
2263
2264 return buf;
2265 }
2266
2267 static int m_show(struct seq_file *m, void *p)
2268 {
2269 struct module *mod = list_entry(p, struct module, list);
2270 char buf[8];
2271
2272 seq_printf(m, "%s %lu",
2273 mod->name, mod->init_size + mod->core_size);
2274 print_unload_info(m, mod);
2275
2276 /* Informative for users. */
2277 seq_printf(m, " %s",
2278 mod->state == MODULE_STATE_GOING ? "Unloading":
2279 mod->state == MODULE_STATE_COMING ? "Loading":
2280 "Live");
2281 /* Used by oprofile and other similar tools. */
2282 seq_printf(m, " 0x%p", mod->module_core);
2283
2284 /* Taints info */
2285 if (mod->taints)
2286 seq_printf(m, " %s", taint_flags(mod->taints, buf));
2287
2288 seq_printf(m, "\n");
2289 return 0;
2290 }
2291
2292 /* Format: modulename size refcount deps address
2293
2294 Where refcount is a number or -, and deps is a comma-separated list
2295 of depends or -.
2296 */
2297 const struct seq_operations modules_op = {
2298 .start = m_start,
2299 .next = m_next,
2300 .stop = m_stop,
2301 .show = m_show
2302 };
2303
2304 /* Given an address, look for it in the module exception tables. */
2305 const struct exception_table_entry *search_module_extables(unsigned long addr)
2306 {
2307 const struct exception_table_entry *e = NULL;
2308 struct module *mod;
2309
2310 preempt_disable();
2311 list_for_each_entry(mod, &modules, list) {
2312 if (mod->num_exentries == 0)
2313 continue;
2314
2315 e = search_extable(mod->extable,
2316 mod->extable + mod->num_exentries - 1,
2317 addr);
2318 if (e)
2319 break;
2320 }
2321 preempt_enable();
2322
2323 /* Now, if we found one, we are running inside it now, hence
2324 we cannot unload the module, hence no refcnt needed. */
2325 return e;
2326 }
2327
2328 /*
2329 * Is this a valid module address?
2330 */
2331 int is_module_address(unsigned long addr)
2332 {
2333 struct module *mod;
2334
2335 preempt_disable();
2336
2337 list_for_each_entry(mod, &modules, list) {
2338 if (within(addr, mod->module_core, mod->core_size)) {
2339 preempt_enable();
2340 return 1;
2341 }
2342 }
2343
2344 preempt_enable();
2345
2346 return 0;
2347 }
2348
2349
2350 /* Is this a valid kernel address? */
2351 struct module *__module_text_address(unsigned long addr)
2352 {
2353 struct module *mod;
2354
2355 list_for_each_entry(mod, &modules, list)
2356 if (within(addr, mod->module_init, mod->init_text_size)
2357 || within(addr, mod->module_core, mod->core_text_size))
2358 return mod;
2359 return NULL;
2360 }
2361
2362 struct module *module_text_address(unsigned long addr)
2363 {
2364 struct module *mod;
2365
2366 preempt_disable();
2367 mod = __module_text_address(addr);
2368 preempt_enable();
2369
2370 return mod;
2371 }
2372
2373 /* Don't grab lock, we're oopsing. */
2374 void print_modules(void)
2375 {
2376 struct module *mod;
2377 char buf[8];
2378
2379 printk("Modules linked in:");
2380 list_for_each_entry(mod, &modules, list)
2381 printk(" %s%s", mod->name, taint_flags(mod->taints, buf));
2382 printk("\n");
2383 }
2384
2385 #ifdef CONFIG_SYSFS
2386 static char *make_driver_name(struct device_driver *drv)
2387 {
2388 char *driver_name;
2389
2390 driver_name = kmalloc(strlen(drv->name) + strlen(drv->bus->name) + 2,
2391 GFP_KERNEL);
2392 if (!driver_name)
2393 return NULL;
2394
2395 sprintf(driver_name, "%s:%s", drv->bus->name, drv->name);
2396 return driver_name;
2397 }
2398
2399 static void module_create_drivers_dir(struct module_kobject *mk)
2400 {
2401 if (!mk || mk->drivers_dir)
2402 return;
2403
2404 mk->drivers_dir = kobject_add_dir(&mk->kobj, "drivers");
2405 }
2406
2407 void module_add_driver(struct module *mod, struct device_driver *drv)
2408 {
2409 char *driver_name;
2410 int no_warn;
2411 struct module_kobject *mk = NULL;
2412
2413 if (!drv)
2414 return;
2415
2416 if (mod)
2417 mk = &mod->mkobj;
2418 else if (drv->mod_name) {
2419 struct kobject *mkobj;
2420
2421 /* Lookup built-in module entry in /sys/modules */
2422 mkobj = kset_find_obj(&module_subsys, drv->mod_name);
2423 if (mkobj) {
2424 mk = container_of(mkobj, struct module_kobject, kobj);
2425 /* remember our module structure */
2426 drv->mkobj = mk;
2427 /* kset_find_obj took a reference */
2428 kobject_put(mkobj);
2429 }
2430 }
2431
2432 if (!mk)
2433 return;
2434
2435 /* Don't check return codes; these calls are idempotent */
2436 no_warn = sysfs_create_link(&drv->kobj, &mk->kobj, "module");
2437 driver_name = make_driver_name(drv);
2438 if (driver_name) {
2439 module_create_drivers_dir(mk);
2440 no_warn = sysfs_create_link(mk->drivers_dir, &drv->kobj,
2441 driver_name);
2442 kfree(driver_name);
2443 }
2444 }
2445 EXPORT_SYMBOL(module_add_driver);
2446
2447 void module_remove_driver(struct device_driver *drv)
2448 {
2449 struct module_kobject *mk = NULL;
2450 char *driver_name;
2451
2452 if (!drv)
2453 return;
2454
2455 sysfs_remove_link(&drv->kobj, "module");
2456
2457 if (drv->owner)
2458 mk = &drv->owner->mkobj;
2459 else if (drv->mkobj)
2460 mk = drv->mkobj;
2461 if (mk && mk->drivers_dir) {
2462 driver_name = make_driver_name(drv);
2463 if (driver_name) {
2464 sysfs_remove_link(mk->drivers_dir, driver_name);
2465 kfree(driver_name);
2466 }
2467 }
2468 }
2469 EXPORT_SYMBOL(module_remove_driver);
2470 #endif
2471
2472 #ifdef CONFIG_MODVERSIONS
2473 /* Generate the signature for struct module here, too, for modversions. */
2474 void struct_module(struct module *mod) { return; }
2475 EXPORT_SYMBOL(struct_module);
2476 #endif
WRT350N Kernel Patches