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[PATCH] core-dumping unreadable binaries via PT_INTERP
[linux-2.6/verdex.git] / kernel / module.c
blobd0f2260a02105902fba2217e51451349777ca21d
1 /*
2 Copyright (C) 2002 Richard Henderson
3 Copyright (C) 2001 Rusty Russell, 2002 Rusty Russell IBM.
4
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 2 of the License, or
8 (at your option) any later version.
9
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
14
15 You should have received a copy of the GNU General Public License
16 along with this program; if not, write to the Free Software
17 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 */
19 #include <linux/module.h>
20 #include <linux/moduleloader.h>
21 #include <linux/init.h>
22 #include <linux/kernel.h>
23 #include <linux/slab.h>
24 #include <linux/vmalloc.h>
25 #include <linux/elf.h>
26 #include <linux/seq_file.h>
27 #include <linux/syscalls.h>
28 #include <linux/fcntl.h>
29 #include <linux/rcupdate.h>
30 #include <linux/capability.h>
31 #include <linux/cpu.h>
32 #include <linux/moduleparam.h>
33 #include <linux/errno.h>
34 #include <linux/err.h>
35 #include <linux/vermagic.h>
36 #include <linux/notifier.h>
37 #include <linux/sched.h>
38 #include <linux/stop_machine.h>
39 #include <linux/device.h>
40 #include <linux/string.h>
41 #include <linux/mutex.h>
42 #include <linux/unwind.h>
43 #include <asm/uaccess.h>
44 #include <asm/semaphore.h>
45 #include <asm/cacheflush.h>
46 #include <linux/license.h>
47
48 #if 0
49 #define DEBUGP printk
50 #else
51 #define DEBUGP(fmt , a...)
52 #endif
53
54 #ifndef ARCH_SHF_SMALL
55 #define ARCH_SHF_SMALL 0
56 #endif
57
58 /* If this is set, the section belongs in the init part of the module */
59 #define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
60
61 /* Protects module list */
62 static DEFINE_SPINLOCK(modlist_lock);
63
64 /* List of modules, protected by module_mutex AND modlist_lock */
65 static DEFINE_MUTEX(module_mutex);
66 static LIST_HEAD(modules);
67
68 static BLOCKING_NOTIFIER_HEAD(module_notify_list);
69
70 int register_module_notifier(struct notifier_block * nb)
71 {
72 return blocking_notifier_chain_register(&module_notify_list, nb);
73 }
74 EXPORT_SYMBOL(register_module_notifier);
75
76 int unregister_module_notifier(struct notifier_block * nb)
77 {
78 return blocking_notifier_chain_unregister(&module_notify_list, nb);
79 }
80 EXPORT_SYMBOL(unregister_module_notifier);
81
82 /* We require a truly strong try_module_get() */
83 static inline int strong_try_module_get(struct module *mod)
84 {
85 if (mod && mod->state == MODULE_STATE_COMING)
86 return 0;
87 return try_module_get(mod);
88 }
89
90 static inline void add_taint_module(struct module *mod, unsigned flag)
91 {
92 add_taint(flag);
93 mod->taints |= flag;
94 }
95
96 /* A thread that wants to hold a reference to a module only while it
97 * is running can call ths to safely exit.
98 * nfsd and lockd use this.
99 */
100 void __module_put_and_exit(struct module *mod, long code)
101 {
102 module_put(mod);
103 do_exit(code);
104 }
105 EXPORT_SYMBOL(__module_put_and_exit);
106
107 /* Find a module section: 0 means not found. */
108 static unsigned int find_sec(Elf_Ehdr *hdr,
109 Elf_Shdr *sechdrs,
110 const char *secstrings,
111 const char *name)
112 {
113 unsigned int i;
114
115 for (i = 1; i < hdr->e_shnum; i++)
116 /* Alloc bit cleared means "ignore it." */
117 if ((sechdrs[i].sh_flags & SHF_ALLOC)
118 && strcmp(secstrings+sechdrs[i].sh_name, name) == 0)
119 return i;
120 return 0;
121 }
122
123 /* Provided by the linker */
124 extern const struct kernel_symbol __start___ksymtab[];
125 extern const struct kernel_symbol __stop___ksymtab[];
126 extern const struct kernel_symbol __start___ksymtab_gpl[];
127 extern const struct kernel_symbol __stop___ksymtab_gpl[];
128 extern const struct kernel_symbol __start___ksymtab_gpl_future[];
129 extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
130 extern const struct kernel_symbol __start___ksymtab_unused[];
131 extern const struct kernel_symbol __stop___ksymtab_unused[];
132 extern const struct kernel_symbol __start___ksymtab_unused_gpl[];
133 extern const struct kernel_symbol __stop___ksymtab_unused_gpl[];
134 extern const struct kernel_symbol __start___ksymtab_gpl_future[];
135 extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
136 extern const unsigned long __start___kcrctab[];
137 extern const unsigned long __start___kcrctab_gpl[];
138 extern const unsigned long __start___kcrctab_gpl_future[];
139 extern const unsigned long __start___kcrctab_unused[];
140 extern const unsigned long __start___kcrctab_unused_gpl[];
141
142 #ifndef CONFIG_MODVERSIONS
143 #define symversion(base, idx) NULL
144 #else
145 #define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
146 #endif
147
148 /* lookup symbol in given range of kernel_symbols */
149 static const struct kernel_symbol *lookup_symbol(const char *name,
150 const struct kernel_symbol *start,
151 const struct kernel_symbol *stop)
152 {
153 const struct kernel_symbol *ks = start;
154 for (; ks < stop; ks++)
155 if (strcmp(ks->name, name) == 0)
156 return ks;
157 return NULL;
158 }
159
160 static void printk_unused_warning(const char *name)
161 {
162 printk(KERN_WARNING "Symbol %s is marked as UNUSED, "
163 "however this module is using it.\n", name);
164 printk(KERN_WARNING "This symbol will go away in the future.\n");
165 printk(KERN_WARNING "Please evalute if this is the right api to use, "
166 "and if it really is, submit a report the linux kernel "
167 "mailinglist together with submitting your code for "
168 "inclusion.\n");
169 }
170
171 /* Find a symbol, return value, crc and module which owns it */
172 static unsigned long __find_symbol(const char *name,
173 struct module **owner,
174 const unsigned long **crc,
175 int gplok)
176 {
177 struct module *mod;
178 const struct kernel_symbol *ks;
179
180 /* Core kernel first. */
181 *owner = NULL;
182 ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
183 if (ks) {
184 *crc = symversion(__start___kcrctab, (ks - __start___ksymtab));
185 return ks->value;
186 }
187 if (gplok) {
188 ks = lookup_symbol(name, __start___ksymtab_gpl,
189 __stop___ksymtab_gpl);
190 if (ks) {
191 *crc = symversion(__start___kcrctab_gpl,
192 (ks - __start___ksymtab_gpl));
193 return ks->value;
194 }
195 }
196 ks = lookup_symbol(name, __start___ksymtab_gpl_future,
197 __stop___ksymtab_gpl_future);
198 if (ks) {
199 if (!gplok) {
200 printk(KERN_WARNING "Symbol %s is being used "
201 "by a non-GPL module, which will not "
202 "be allowed in the future\n", name);
203 printk(KERN_WARNING "Please see the file "
204 "Documentation/feature-removal-schedule.txt "
205 "in the kernel source tree for more "
206 "details.\n");
207 }
208 *crc = symversion(__start___kcrctab_gpl_future,
209 (ks - __start___ksymtab_gpl_future));
210 return ks->value;
211 }
212
213 ks = lookup_symbol(name, __start___ksymtab_unused,
214 __stop___ksymtab_unused);
215 if (ks) {
216 printk_unused_warning(name);
217 *crc = symversion(__start___kcrctab_unused,
218 (ks - __start___ksymtab_unused));
219 return ks->value;
220 }
221
222 if (gplok)
223 ks = lookup_symbol(name, __start___ksymtab_unused_gpl,
224 __stop___ksymtab_unused_gpl);
225 if (ks) {
226 printk_unused_warning(name);
227 *crc = symversion(__start___kcrctab_unused_gpl,
228 (ks - __start___ksymtab_unused_gpl));
229 return ks->value;
230 }
231
232 /* Now try modules. */
233 list_for_each_entry(mod, &modules, list) {
234 *owner = mod;
235 ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
236 if (ks) {
237 *crc = symversion(mod->crcs, (ks - mod->syms));
238 return ks->value;
239 }
240
241 if (gplok) {
242 ks = lookup_symbol(name, mod->gpl_syms,
243 mod->gpl_syms + mod->num_gpl_syms);
244 if (ks) {
245 *crc = symversion(mod->gpl_crcs,
246 (ks - mod->gpl_syms));
247 return ks->value;
248 }
249 }
250 ks = lookup_symbol(name, mod->unused_syms, mod->unused_syms + mod->num_unused_syms);
251 if (ks) {
252 printk_unused_warning(name);
253 *crc = symversion(mod->unused_crcs, (ks - mod->unused_syms));
254 return ks->value;
255 }
256
257 if (gplok) {
258 ks = lookup_symbol(name, mod->unused_gpl_syms,
259 mod->unused_gpl_syms + mod->num_unused_gpl_syms);
260 if (ks) {
261 printk_unused_warning(name);
262 *crc = symversion(mod->unused_gpl_crcs,
263 (ks - mod->unused_gpl_syms));
264 return ks->value;
265 }
266 }
267 ks = lookup_symbol(name, mod->gpl_future_syms,
268 (mod->gpl_future_syms +
269 mod->num_gpl_future_syms));
270 if (ks) {
271 if (!gplok) {
272 printk(KERN_WARNING "Symbol %s is being used "
273 "by a non-GPL module, which will not "
274 "be allowed in the future\n", name);
275 printk(KERN_WARNING "Please see the file "
276 "Documentation/feature-removal-schedule.txt "
277 "in the kernel source tree for more "
278 "details.\n");
279 }
280 *crc = symversion(mod->gpl_future_crcs,
281 (ks - mod->gpl_future_syms));
282 return ks->value;
283 }
284 }
285 DEBUGP("Failed to find symbol %s\n", name);
286 return 0;
287 }
288
289 /* Search for module by name: must hold module_mutex. */
290 static struct module *find_module(const char *name)
291 {
292 struct module *mod;
293
294 list_for_each_entry(mod, &modules, list) {
295 if (strcmp(mod->name, name) == 0)
296 return mod;
297 }
298 return NULL;
299 }
300
301 #ifdef CONFIG_SMP
302 /* Number of blocks used and allocated. */
303 static unsigned int pcpu_num_used, pcpu_num_allocated;
304 /* Size of each block. -ve means used. */
305 static int *pcpu_size;
306
307 static int split_block(unsigned int i, unsigned short size)
308 {
309 /* Reallocation required? */
310 if (pcpu_num_used + 1 > pcpu_num_allocated) {
311 int *new = kmalloc(sizeof(new[0]) * pcpu_num_allocated*2,
312 GFP_KERNEL);
313 if (!new)
314 return 0;
315
316 memcpy(new, pcpu_size, sizeof(new[0])*pcpu_num_allocated);
317 pcpu_num_allocated *= 2;
318 kfree(pcpu_size);
319 pcpu_size = new;
320 }
321
322 /* Insert a new subblock */
323 memmove(&pcpu_size[i+1], &pcpu_size[i],
324 sizeof(pcpu_size[0]) * (pcpu_num_used - i));
325 pcpu_num_used++;
326
327 pcpu_size[i+1] -= size;
328 pcpu_size[i] = size;
329 return 1;
330 }
331
332 static inline unsigned int block_size(int val)
333 {
334 if (val < 0)
335 return -val;
336 return val;
337 }
338
339 /* Created by linker magic */
340 extern char __per_cpu_start[], __per_cpu_end[];
341
342 static void *percpu_modalloc(unsigned long size, unsigned long align,
343 const char *name)
344 {
345 unsigned long extra;
346 unsigned int i;
347 void *ptr;
348
349 if (align > SMP_CACHE_BYTES) {
350 printk(KERN_WARNING "%s: per-cpu alignment %li > %i\n",
351 name, align, SMP_CACHE_BYTES);
352 align = SMP_CACHE_BYTES;
353 }
354
355 ptr = __per_cpu_start;
356 for (i = 0; i < pcpu_num_used; ptr += block_size(pcpu_size[i]), i++) {
357 /* Extra for alignment requirement. */
358 extra = ALIGN((unsigned long)ptr, align) - (unsigned long)ptr;
359 BUG_ON(i == 0 && extra != 0);
360
361 if (pcpu_size[i] < 0 || pcpu_size[i] < extra + size)
362 continue;
363
364 /* Transfer extra to previous block. */
365 if (pcpu_size[i-1] < 0)
366 pcpu_size[i-1] -= extra;
367 else
368 pcpu_size[i-1] += extra;
369 pcpu_size[i] -= extra;
370 ptr += extra;
371
372 /* Split block if warranted */
373 if (pcpu_size[i] - size > sizeof(unsigned long))
374 if (!split_block(i, size))
375 return NULL;
376
377 /* Mark allocated */
378 pcpu_size[i] = -pcpu_size[i];
379 return ptr;
380 }
381
382 printk(KERN_WARNING "Could not allocate %lu bytes percpu data\n",
383 size);
384 return NULL;
385 }
386
387 static void percpu_modfree(void *freeme)
388 {
389 unsigned int i;
390 void *ptr = __per_cpu_start + block_size(pcpu_size[0]);
391
392 /* First entry is core kernel percpu data. */
393 for (i = 1; i < pcpu_num_used; ptr += block_size(pcpu_size[i]), i++) {
394 if (ptr == freeme) {
395 pcpu_size[i] = -pcpu_size[i];
396 goto free;
397 }
398 }
399 BUG();
400
401 free:
402 /* Merge with previous? */
403 if (pcpu_size[i-1] >= 0) {
404 pcpu_size[i-1] += pcpu_size[i];
405 pcpu_num_used--;
406 memmove(&pcpu_size[i], &pcpu_size[i+1],
407 (pcpu_num_used - i) * sizeof(pcpu_size[0]));
408 i--;
409 }
410 /* Merge with next? */
411 if (i+1 < pcpu_num_used && pcpu_size[i+1] >= 0) {
412 pcpu_size[i] += pcpu_size[i+1];
413 pcpu_num_used--;
414 memmove(&pcpu_size[i+1], &pcpu_size[i+2],
415 (pcpu_num_used - (i+1)) * sizeof(pcpu_size[0]));
416 }
417 }
418
419 static unsigned int find_pcpusec(Elf_Ehdr *hdr,
420 Elf_Shdr *sechdrs,
421 const char *secstrings)
422 {
423 return find_sec(hdr, sechdrs, secstrings, ".data.percpu");
424 }
425
426 static int percpu_modinit(void)
427 {
428 pcpu_num_used = 2;
429 pcpu_num_allocated = 2;
430 pcpu_size = kmalloc(sizeof(pcpu_size[0]) * pcpu_num_allocated,
431 GFP_KERNEL);
432 /* Static in-kernel percpu data (used). */
433 pcpu_size[0] = -ALIGN(__per_cpu_end-__per_cpu_start, SMP_CACHE_BYTES);
434 /* Free room. */
435 pcpu_size[1] = PERCPU_ENOUGH_ROOM + pcpu_size[0];
436 if (pcpu_size[1] < 0) {
437 printk(KERN_ERR "No per-cpu room for modules.\n");
438 pcpu_num_used = 1;
439 }
440
441 return 0;
442 }
443 __initcall(percpu_modinit);
444 #else /* ... !CONFIG_SMP */
445 static inline void *percpu_modalloc(unsigned long size, unsigned long align,
446 const char *name)
447 {
448 return NULL;
449 }
450 static inline void percpu_modfree(void *pcpuptr)
451 {
452 BUG();
453 }
454 static inline unsigned int find_pcpusec(Elf_Ehdr *hdr,
455 Elf_Shdr *sechdrs,
456 const char *secstrings)
457 {
458 return 0;
459 }
460 static inline void percpu_modcopy(void *pcpudst, const void *src,
461 unsigned long size)
462 {
463 /* pcpusec should be 0, and size of that section should be 0. */
464 BUG_ON(size != 0);
465 }
466 #endif /* CONFIG_SMP */
467
468 #define MODINFO_ATTR(field) \
469 static void setup_modinfo_##field(struct module *mod, const char *s) \
470 { \
471 mod->field = kstrdup(s, GFP_KERNEL); \
472 } \
473 static ssize_t show_modinfo_##field(struct module_attribute *mattr, \
474 struct module *mod, char *buffer) \
475 { \
476 return sprintf(buffer, "%s\n", mod->field); \
477 } \
478 static int modinfo_##field##_exists(struct module *mod) \
479 { \
480 return mod->field != NULL; \
481 } \
482 static void free_modinfo_##field(struct module *mod) \
483 { \
484 kfree(mod->field); \
485 mod->field = NULL; \
486 } \
487 static struct module_attribute modinfo_##field = { \
488 .attr = { .name = __stringify(field), .mode = 0444, \
489 .owner = THIS_MODULE }, \
490 .show = show_modinfo_##field, \
491 .setup = setup_modinfo_##field, \
492 .test = modinfo_##field##_exists, \
493 .free = free_modinfo_##field, \
494 };
495
496 MODINFO_ATTR(version);
497 MODINFO_ATTR(srcversion);
498
499 #ifdef CONFIG_MODULE_UNLOAD
500 /* Init the unload section of the module. */
501 static void module_unload_init(struct module *mod)
502 {
503 unsigned int i;
504
505 INIT_LIST_HEAD(&mod->modules_which_use_me);
506 for (i = 0; i < NR_CPUS; i++)
507 local_set(&mod->ref[i].count, 0);
508 /* Hold reference count during initialization. */
509 local_set(&mod->ref[raw_smp_processor_id()].count, 1);
510 /* Backwards compatibility macros put refcount during init. */
511 mod->waiter = current;
512 }
513
514 /* modules using other modules */
515 struct module_use
516 {
517 struct list_head list;
518 struct module *module_which_uses;
519 };
520
521 /* Does a already use b? */
522 static int already_uses(struct module *a, struct module *b)
523 {
524 struct module_use *use;
525
526 list_for_each_entry(use, &b->modules_which_use_me, list) {
527 if (use->module_which_uses == a) {
528 DEBUGP("%s uses %s!\n", a->name, b->name);
529 return 1;
530 }
531 }
532 DEBUGP("%s does not use %s!\n", a->name, b->name);
533 return 0;
534 }
535
536 /* Module a uses b */
537 static int use_module(struct module *a, struct module *b)
538 {
539 struct module_use *use;
540 if (b == NULL || already_uses(a, b)) return 1;
541
542 if (!strong_try_module_get(b))
543 return 0;
544
545 DEBUGP("Allocating new usage for %s.\n", a->name);
546 use = kmalloc(sizeof(*use), GFP_ATOMIC);
547 if (!use) {
548 printk("%s: out of memory loading\n", a->name);
549 module_put(b);
550 return 0;
551 }
552
553 use->module_which_uses = a;
554 list_add(&use->list, &b->modules_which_use_me);
555 return 1;
556 }
557
558 /* Clear the unload stuff of the module. */
559 static void module_unload_free(struct module *mod)
560 {
561 struct module *i;
562
563 list_for_each_entry(i, &modules, list) {
564 struct module_use *use;
565
566 list_for_each_entry(use, &i->modules_which_use_me, list) {
567 if (use->module_which_uses == mod) {
568 DEBUGP("%s unusing %s\n", mod->name, i->name);
569 module_put(i);
570 list_del(&use->list);
571 kfree(use);
572 /* There can be at most one match. */
573 break;
574 }
575 }
576 }
577 }
578
579 #ifdef CONFIG_MODULE_FORCE_UNLOAD
580 static inline int try_force_unload(unsigned int flags)
581 {
582 int ret = (flags & O_TRUNC);
583 if (ret)
584 add_taint(TAINT_FORCED_RMMOD);
585 return ret;
586 }
587 #else
588 static inline int try_force_unload(unsigned int flags)
589 {
590 return 0;
591 }
592 #endif /* CONFIG_MODULE_FORCE_UNLOAD */
593
594 struct stopref
595 {
596 struct module *mod;
597 int flags;
598 int *forced;
599 };
600
601 /* Whole machine is stopped with interrupts off when this runs. */
602 static int __try_stop_module(void *_sref)
603 {
604 struct stopref *sref = _sref;
605
606 /* If it's not unused, quit unless we are told to block. */
607 if ((sref->flags & O_NONBLOCK) && module_refcount(sref->mod) != 0) {
608 if (!(*sref->forced = try_force_unload(sref->flags)))
609 return -EWOULDBLOCK;
610 }
611
612 /* Mark it as dying. */
613 sref->mod->state = MODULE_STATE_GOING;
614 return 0;
615 }
616
617 static int try_stop_module(struct module *mod, int flags, int *forced)
618 {
619 struct stopref sref = { mod, flags, forced };
620
621 return stop_machine_run(__try_stop_module, &sref, NR_CPUS);
622 }
623
624 unsigned int module_refcount(struct module *mod)
625 {
626 unsigned int i, total = 0;
627
628 for (i = 0; i < NR_CPUS; i++)
629 total += local_read(&mod->ref[i].count);
630 return total;
631 }
632 EXPORT_SYMBOL(module_refcount);
633
634 /* This exists whether we can unload or not */
635 static void free_module(struct module *mod);
636
637 static void wait_for_zero_refcount(struct module *mod)
638 {
639 /* Since we might sleep for some time, drop the semaphore first */
640 mutex_unlock(&module_mutex);
641 for (;;) {
642 DEBUGP("Looking at refcount...\n");
643 set_current_state(TASK_UNINTERRUPTIBLE);
644 if (module_refcount(mod) == 0)
645 break;
646 schedule();
647 }
648 current->state = TASK_RUNNING;
649 mutex_lock(&module_mutex);
650 }
651
652 asmlinkage long
653 sys_delete_module(const char __user *name_user, unsigned int flags)
654 {
655 struct module *mod;
656 char name[MODULE_NAME_LEN];
657 int ret, forced = 0;
658
659 if (!capable(CAP_SYS_MODULE))
660 return -EPERM;
661
662 if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
663 return -EFAULT;
664 name[MODULE_NAME_LEN-1] = '\0';
665
666 if (mutex_lock_interruptible(&module_mutex) != 0)
667 return -EINTR;
668
669 mod = find_module(name);
670 if (!mod) {
671 ret = -ENOENT;
672 goto out;
673 }
674
675 if (!list_empty(&mod->modules_which_use_me)) {
676 /* Other modules depend on us: get rid of them first. */
677 ret = -EWOULDBLOCK;
678 goto out;
679 }
680
681 /* Doing init or already dying? */
682 if (mod->state != MODULE_STATE_LIVE) {
683 /* FIXME: if (force), slam module count and wake up
684 waiter --RR */
685 DEBUGP("%s already dying\n", mod->name);
686 ret = -EBUSY;
687 goto out;
688 }
689
690 /* If it has an init func, it must have an exit func to unload */
691 if ((mod->init != NULL && mod->exit == NULL)
692 || mod->unsafe) {
693 forced = try_force_unload(flags);
694 if (!forced) {
695 /* This module can't be removed */
696 ret = -EBUSY;
697 goto out;
698 }
699 }
700
701 /* Set this up before setting mod->state */
702 mod->waiter = current;
703
704 /* Stop the machine so refcounts can't move and disable module. */
705 ret = try_stop_module(mod, flags, &forced);
706 if (ret != 0)
707 goto out;
708
709 /* Never wait if forced. */
710 if (!forced && module_refcount(mod) != 0)
711 wait_for_zero_refcount(mod);
712
713 /* Final destruction now noone is using it. */
714 if (mod->exit != NULL) {
715 mutex_unlock(&module_mutex);
716 mod->exit();
717 mutex_lock(&module_mutex);
718 }
719 free_module(mod);
720
721 out:
722 mutex_unlock(&module_mutex);
723 return ret;
724 }
725
726 static void print_unload_info(struct seq_file *m, struct module *mod)
727 {
728 struct module_use *use;
729 int printed_something = 0;
730
731 seq_printf(m, " %u ", module_refcount(mod));
732
733 /* Always include a trailing , so userspace can differentiate
734 between this and the old multi-field proc format. */
735 list_for_each_entry(use, &mod->modules_which_use_me, list) {
736 printed_something = 1;
737 seq_printf(m, "%s,", use->module_which_uses->name);
738 }
739
740 if (mod->unsafe) {
741 printed_something = 1;
742 seq_printf(m, "[unsafe],");
743 }
744
745 if (mod->init != NULL && mod->exit == NULL) {
746 printed_something = 1;
747 seq_printf(m, "[permanent],");
748 }
749
750 if (!printed_something)
751 seq_printf(m, "-");
752 }
753
754 void __symbol_put(const char *symbol)
755 {
756 struct module *owner;
757 unsigned long flags;
758 const unsigned long *crc;
759
760 spin_lock_irqsave(&modlist_lock, flags);
761 if (!__find_symbol(symbol, &owner, &crc, 1))
762 BUG();
763 module_put(owner);
764 spin_unlock_irqrestore(&modlist_lock, flags);
765 }
766 EXPORT_SYMBOL(__symbol_put);
767
768 void symbol_put_addr(void *addr)
769 {
770 struct module *modaddr;
771
772 if (core_kernel_text((unsigned long)addr))
773 return;
774
775 if (!(modaddr = module_text_address((unsigned long)addr)))
776 BUG();
777 module_put(modaddr);
778 }
779 EXPORT_SYMBOL_GPL(symbol_put_addr);
780
781 static ssize_t show_refcnt(struct module_attribute *mattr,
782 struct module *mod, char *buffer)
783 {
784 /* sysfs holds a reference */
785 return sprintf(buffer, "%u\n", module_refcount(mod)-1);
786 }
787
788 static struct module_attribute refcnt = {
789 .attr = { .name = "refcnt", .mode = 0444, .owner = THIS_MODULE },
790 .show = show_refcnt,
791 };
792
793 void module_put(struct module *module)
794 {
795 if (module) {
796 unsigned int cpu = get_cpu();
797 local_dec(&module->ref[cpu].count);
798 /* Maybe they're waiting for us to drop reference? */
799 if (unlikely(!module_is_live(module)))
800 wake_up_process(module->waiter);
801 put_cpu();
802 }
803 }
804 EXPORT_SYMBOL(module_put);
805
806 #else /* !CONFIG_MODULE_UNLOAD */
807 static void print_unload_info(struct seq_file *m, struct module *mod)
808 {
809 /* We don't know the usage count, or what modules are using. */
810 seq_printf(m, " - -");
811 }
812
813 static inline void module_unload_free(struct module *mod)
814 {
815 }
816
817 static inline int use_module(struct module *a, struct module *b)
818 {
819 return strong_try_module_get(b);
820 }
821
822 static inline void module_unload_init(struct module *mod)
823 {
824 }
825 #endif /* CONFIG_MODULE_UNLOAD */
826
827 static ssize_t show_initstate(struct module_attribute *mattr,
828 struct module *mod, char *buffer)
829 {
830 const char *state = "unknown";
831
832 switch (mod->state) {
833 case MODULE_STATE_LIVE:
834 state = "live";
835 break;
836 case MODULE_STATE_COMING:
837 state = "coming";
838 break;
839 case MODULE_STATE_GOING:
840 state = "going";
841 break;
842 }
843 return sprintf(buffer, "%s\n", state);
844 }
845
846 static struct module_attribute initstate = {
847 .attr = { .name = "initstate", .mode = 0444, .owner = THIS_MODULE },
848 .show = show_initstate,
849 };
850
851 static struct module_attribute *modinfo_attrs[] = {
852 &modinfo_version,
853 &modinfo_srcversion,
854 &initstate,
855 #ifdef CONFIG_MODULE_UNLOAD
856 &refcnt,
857 #endif
858 NULL,
859 };
860
861 static const char vermagic[] = VERMAGIC_STRING;
862
863 #ifdef CONFIG_MODVERSIONS
864 static int check_version(Elf_Shdr *sechdrs,
865 unsigned int versindex,
866 const char *symname,
867 struct module *mod,
868 const unsigned long *crc)
869 {
870 unsigned int i, num_versions;
871 struct modversion_info *versions;
872
873 /* Exporting module didn't supply crcs? OK, we're already tainted. */
874 if (!crc)
875 return 1;
876
877 versions = (void *) sechdrs[versindex].sh_addr;
878 num_versions = sechdrs[versindex].sh_size
879 / sizeof(struct modversion_info);
880
881 for (i = 0; i < num_versions; i++) {
882 if (strcmp(versions[i].name, symname) != 0)
883 continue;
884
885 if (versions[i].crc == *crc)
886 return 1;
887 printk("%s: disagrees about version of symbol %s\n",
888 mod->name, symname);
889 DEBUGP("Found checksum %lX vs module %lX\n",
890 *crc, versions[i].crc);
891 return 0;
892 }
893 /* Not in module's version table. OK, but that taints the kernel. */
894 if (!(tainted & TAINT_FORCED_MODULE))
895 printk("%s: no version for \"%s\" found: kernel tainted.\n",
896 mod->name, symname);
897 add_taint_module(mod, TAINT_FORCED_MODULE);
898 return 1;
899 }
900
901 static inline int check_modstruct_version(Elf_Shdr *sechdrs,
902 unsigned int versindex,
903 struct module *mod)
904 {
905 const unsigned long *crc;
906 struct module *owner;
907
908 if (!__find_symbol("struct_module", &owner, &crc, 1))
909 BUG();
910 return check_version(sechdrs, versindex, "struct_module", mod,
911 crc);
912 }
913
914 /* First part is kernel version, which we ignore. */
915 static inline int same_magic(const char *amagic, const char *bmagic)
916 {
917 amagic += strcspn(amagic, " ");
918 bmagic += strcspn(bmagic, " ");
919 return strcmp(amagic, bmagic) == 0;
920 }
921 #else
922 static inline int check_version(Elf_Shdr *sechdrs,
923 unsigned int versindex,
924 const char *symname,
925 struct module *mod,
926 const unsigned long *crc)
927 {
928 return 1;
929 }
930
931 static inline int check_modstruct_version(Elf_Shdr *sechdrs,
932 unsigned int versindex,
933 struct module *mod)
934 {
935 return 1;
936 }
937
938 static inline int same_magic(const char *amagic, const char *bmagic)
939 {
940 return strcmp(amagic, bmagic) == 0;
941 }
942 #endif /* CONFIG_MODVERSIONS */
943
944 /* Resolve a symbol for this module. I.e. if we find one, record usage.
945 Must be holding module_mutex. */
946 static unsigned long resolve_symbol(Elf_Shdr *sechdrs,
947 unsigned int versindex,
948 const char *name,
949 struct module *mod)
950 {
951 struct module *owner;
952 unsigned long ret;
953 const unsigned long *crc;
954
955 ret = __find_symbol(name, &owner, &crc,
956 !(mod->taints & TAINT_PROPRIETARY_MODULE));
957 if (ret) {
958 /* use_module can fail due to OOM, or module unloading */
959 if (!check_version(sechdrs, versindex, name, mod, crc) ||
960 !use_module(mod, owner))
961 ret = 0;
962 }
963 return ret;
964 }
965
966
967 /*
968 * /sys/module/foo/sections stuff
969 * J. Corbet <corbet@lwn.net>
970 */
971 #ifdef CONFIG_KALLSYMS
972 static ssize_t module_sect_show(struct module_attribute *mattr,
973 struct module *mod, char *buf)
974 {
975 struct module_sect_attr *sattr =
976 container_of(mattr, struct module_sect_attr, mattr);
977 return sprintf(buf, "0x%lx\n", sattr->address);
978 }
979
980 static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
981 {
982 int section;
983
984 for (section = 0; section < sect_attrs->nsections; section++)
985 kfree(sect_attrs->attrs[section].name);
986 kfree(sect_attrs);
987 }
988
989 static void add_sect_attrs(struct module *mod, unsigned int nsect,
990 char *secstrings, Elf_Shdr *sechdrs)
991 {
992 unsigned int nloaded = 0, i, size[2];
993 struct module_sect_attrs *sect_attrs;
994 struct module_sect_attr *sattr;
995 struct attribute **gattr;
996
997 /* Count loaded sections and allocate structures */
998 for (i = 0; i < nsect; i++)
999 if (sechdrs[i].sh_flags & SHF_ALLOC)
1000 nloaded++;
1001 size[0] = ALIGN(sizeof(*sect_attrs)
1002 + nloaded * sizeof(sect_attrs->attrs[0]),
1003 sizeof(sect_attrs->grp.attrs[0]));
1004 size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]);
1005 sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
1006 if (sect_attrs == NULL)
1007 return;
1008
1009 /* Setup section attributes. */
1010 sect_attrs->grp.name = "sections";
1011 sect_attrs->grp.attrs = (void *)sect_attrs + size[0];
1012
1013 sect_attrs->nsections = 0;
1014 sattr = &sect_attrs->attrs[0];
1015 gattr = &sect_attrs->grp.attrs[0];
1016 for (i = 0; i < nsect; i++) {
1017 if (! (sechdrs[i].sh_flags & SHF_ALLOC))
1018 continue;
1019 sattr->address = sechdrs[i].sh_addr;
1020 sattr->name = kstrdup(secstrings + sechdrs[i].sh_name,
1021 GFP_KERNEL);
1022 if (sattr->name == NULL)
1023 goto out;
1024 sect_attrs->nsections++;
1025 sattr->mattr.show = module_sect_show;
1026 sattr->mattr.store = NULL;
1027 sattr->mattr.attr.name = sattr->name;
1028 sattr->mattr.attr.owner = mod;
1029 sattr->mattr.attr.mode = S_IRUGO;
1030 *(gattr++) = &(sattr++)->mattr.attr;
1031 }
1032 *gattr = NULL;
1033
1034 if (sysfs_create_group(&mod->mkobj.kobj, &sect_attrs->grp))
1035 goto out;
1036
1037 mod->sect_attrs = sect_attrs;
1038 return;
1039 out:
1040 free_sect_attrs(sect_attrs);
1041 }
1042
1043 static void remove_sect_attrs(struct module *mod)
1044 {
1045 if (mod->sect_attrs) {
1046 sysfs_remove_group(&mod->mkobj.kobj,
1047 &mod->sect_attrs->grp);
1048 /* We are positive that no one is using any sect attrs
1049 * at this point. Deallocate immediately. */
1050 free_sect_attrs(mod->sect_attrs);
1051 mod->sect_attrs = NULL;
1052 }
1053 }
1054
1055 #else
1056
1057 static inline void add_sect_attrs(struct module *mod, unsigned int nsect,
1058 char *sectstrings, Elf_Shdr *sechdrs)
1059 {
1060 }
1061
1062 static inline void remove_sect_attrs(struct module *mod)
1063 {
1064 }
1065 #endif /* CONFIG_KALLSYMS */
1066
1067 static int module_add_modinfo_attrs(struct module *mod)
1068 {
1069 struct module_attribute *attr;
1070 struct module_attribute *temp_attr;
1071 int error = 0;
1072 int i;
1073
1074 mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
1075 (ARRAY_SIZE(modinfo_attrs) + 1)),
1076 GFP_KERNEL);
1077 if (!mod->modinfo_attrs)
1078 return -ENOMEM;
1079
1080 temp_attr = mod->modinfo_attrs;
1081 for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
1082 if (!attr->test ||
1083 (attr->test && attr->test(mod))) {
1084 memcpy(temp_attr, attr, sizeof(*temp_attr));
1085 temp_attr->attr.owner = mod;
1086 error = sysfs_create_file(&mod->mkobj.kobj,&temp_attr->attr);
1087 ++temp_attr;
1088 }
1089 }
1090 return error;
1091 }
1092
1093 static void module_remove_modinfo_attrs(struct module *mod)
1094 {
1095 struct module_attribute *attr;
1096 int i;
1097
1098 for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
1099 /* pick a field to test for end of list */
1100 if (!attr->attr.name)
1101 break;
1102 sysfs_remove_file(&mod->mkobj.kobj,&attr->attr);
1103 if (attr->free)
1104 attr->free(mod);
1105 }
1106 kfree(mod->modinfo_attrs);
1107 }
1108
1109 static int mod_sysfs_setup(struct module *mod,
1110 struct kernel_param *kparam,
1111 unsigned int num_params)
1112 {
1113 int err;
1114
1115 if (!module_subsys.kset.subsys) {
1116 printk(KERN_ERR "%s: module_subsys not initialized\n",
1117 mod->name);
1118 err = -EINVAL;
1119 goto out;
1120 }
1121 memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
1122 err = kobject_set_name(&mod->mkobj.kobj, "%s", mod->name);
1123 if (err)
1124 goto out;
1125 kobj_set_kset_s(&mod->mkobj, module_subsys);
1126 mod->mkobj.mod = mod;
1127
1128 /* delay uevent until full sysfs population */
1129 kobject_init(&mod->mkobj.kobj);
1130 err = kobject_add(&mod->mkobj.kobj);
1131 if (err)
1132 goto out;
1133
1134 mod->drivers_dir = kobject_add_dir(&mod->mkobj.kobj, "drivers");
1135 if (!mod->drivers_dir) {
1136 err = -ENOMEM;
1137 goto out_unreg;
1138 }
1139
1140 err = module_param_sysfs_setup(mod, kparam, num_params);
1141 if (err)
1142 goto out_unreg_drivers;
1143
1144 err = module_add_modinfo_attrs(mod);
1145 if (err)
1146 goto out_unreg_param;
1147
1148 kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
1149 return 0;
1150
1151 out_unreg_param:
1152 module_param_sysfs_remove(mod);
1153 out_unreg_drivers:
1154 kobject_unregister(mod->drivers_dir);
1155 out_unreg:
1156 kobject_del(&mod->mkobj.kobj);
1157 kobject_put(&mod->mkobj.kobj);
1158 out:
1159 return err;
1160 }
1161
1162 static void mod_kobject_remove(struct module *mod)
1163 {
1164 module_remove_modinfo_attrs(mod);
1165 module_param_sysfs_remove(mod);
1166 kobject_unregister(mod->drivers_dir);
1167
1168 kobject_unregister(&mod->mkobj.kobj);
1169 }
1170
1171 /*
1172 * unlink the module with the whole machine is stopped with interrupts off
1173 * - this defends against kallsyms not taking locks
1174 */
1175 static int __unlink_module(void *_mod)
1176 {
1177 struct module *mod = _mod;
1178 list_del(&mod->list);
1179 return 0;
1180 }
1181
1182 /* Free a module, remove from lists, etc (must hold module mutex). */
1183 static void free_module(struct module *mod)
1184 {
1185 /* Delete from various lists */
1186 stop_machine_run(__unlink_module, mod, NR_CPUS);
1187 remove_sect_attrs(mod);
1188 mod_kobject_remove(mod);
1189
1190 unwind_remove_table(mod->unwind_info, 0);
1191
1192 /* Arch-specific cleanup. */
1193 module_arch_cleanup(mod);
1194
1195 /* Module unload stuff */
1196 module_unload_free(mod);
1197
1198 /* This may be NULL, but that's OK */
1199 module_free(mod, mod->module_init);
1200 kfree(mod->args);
1201 if (mod->percpu)
1202 percpu_modfree(mod->percpu);
1203
1204 /* Free lock-classes: */
1205 lockdep_free_key_range(mod->module_core, mod->core_size);
1206
1207 /* Finally, free the core (containing the module structure) */
1208 module_free(mod, mod->module_core);
1209 }
1210
1211 void *__symbol_get(const char *symbol)
1212 {
1213 struct module *owner;
1214 unsigned long value, flags;
1215 const unsigned long *crc;
1216
1217 spin_lock_irqsave(&modlist_lock, flags);
1218 value = __find_symbol(symbol, &owner, &crc, 1);
1219 if (value && !strong_try_module_get(owner))
1220 value = 0;
1221 spin_unlock_irqrestore(&modlist_lock, flags);
1222
1223 return (void *)value;
1224 }
1225 EXPORT_SYMBOL_GPL(__symbol_get);
1226
1227 /*
1228 * Ensure that an exported symbol [global namespace] does not already exist
1229 * in the Kernel or in some other modules exported symbol table.
1230 */
1231 static int verify_export_symbols(struct module *mod)
1232 {
1233 const char *name = NULL;
1234 unsigned long i, ret = 0;
1235 struct module *owner;
1236 const unsigned long *crc;
1237
1238 for (i = 0; i < mod->num_syms; i++)
1239 if (__find_symbol(mod->syms[i].name, &owner, &crc, 1)) {
1240 name = mod->syms[i].name;
1241 ret = -ENOEXEC;
1242 goto dup;
1243 }
1244
1245 for (i = 0; i < mod->num_gpl_syms; i++)
1246 if (__find_symbol(mod->gpl_syms[i].name, &owner, &crc, 1)) {
1247 name = mod->gpl_syms[i].name;
1248 ret = -ENOEXEC;
1249 goto dup;
1250 }
1251
1252 dup:
1253 if (ret)
1254 printk(KERN_ERR "%s: exports duplicate symbol %s (owned by %s)\n",
1255 mod->name, name, module_name(owner));
1256
1257 return ret;
1258 }
1259
1260 /* Change all symbols so that sh_value encodes the pointer directly. */
1261 static int simplify_symbols(Elf_Shdr *sechdrs,
1262 unsigned int symindex,
1263 const char *strtab,
1264 unsigned int versindex,
1265 unsigned int pcpuindex,
1266 struct module *mod)
1267 {
1268 Elf_Sym *sym = (void *)sechdrs[symindex].sh_addr;
1269 unsigned long secbase;
1270 unsigned int i, n = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
1271 int ret = 0;
1272
1273 for (i = 1; i < n; i++) {
1274 switch (sym[i].st_shndx) {
1275 case SHN_COMMON:
1276 /* We compiled with -fno-common. These are not
1277 supposed to happen. */
1278 DEBUGP("Common symbol: %s\n", strtab + sym[i].st_name);
1279 printk("%s: please compile with -fno-common\n",
1280 mod->name);
1281 ret = -ENOEXEC;
1282 break;
1283
1284 case SHN_ABS:
1285 /* Don't need to do anything */
1286 DEBUGP("Absolute symbol: 0x%08lx\n",
1287 (long)sym[i].st_value);
1288 break;
1289
1290 case SHN_UNDEF:
1291 sym[i].st_value
1292 = resolve_symbol(sechdrs, versindex,
1293 strtab + sym[i].st_name, mod);
1294
1295 /* Ok if resolved. */
1296 if (sym[i].st_value != 0)
1297 break;
1298 /* Ok if weak. */
1299 if (ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
1300 break;
1301
1302 printk(KERN_WARNING "%s: Unknown symbol %s\n",
1303 mod->name, strtab + sym[i].st_name);
1304 ret = -ENOENT;
1305 break;
1306
1307 default:
1308 /* Divert to percpu allocation if a percpu var. */
1309 if (sym[i].st_shndx == pcpuindex)
1310 secbase = (unsigned long)mod->percpu;
1311 else
1312 secbase = sechdrs[sym[i].st_shndx].sh_addr;
1313 sym[i].st_value += secbase;
1314 break;
1315 }
1316 }
1317
1318 return ret;
1319 }
1320
1321 /* Update size with this section: return offset. */
1322 static long get_offset(unsigned long *size, Elf_Shdr *sechdr)
1323 {
1324 long ret;
1325
1326 ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
1327 *size = ret + sechdr->sh_size;
1328 return ret;
1329 }
1330
1331 /* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
1332 might -- code, read-only data, read-write data, small data. Tally
1333 sizes, and place the offsets into sh_entsize fields: high bit means it
1334 belongs in init. */
1335 static void layout_sections(struct module *mod,
1336 const Elf_Ehdr *hdr,
1337 Elf_Shdr *sechdrs,
1338 const char *secstrings)
1339 {
1340 static unsigned long const masks[][2] = {
1341 /* NOTE: all executable code must be the first section
1342 * in this array; otherwise modify the text_size
1343 * finder in the two loops below */
1344 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
1345 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
1346 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
1347 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
1348 };
1349 unsigned int m, i;
1350
1351 for (i = 0; i < hdr->e_shnum; i++)
1352 sechdrs[i].sh_entsize = ~0UL;
1353
1354 DEBUGP("Core section allocation order:\n");
1355 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
1356 for (i = 0; i < hdr->e_shnum; ++i) {
1357 Elf_Shdr *s = &sechdrs[i];
1358
1359 if ((s->sh_flags & masks[m][0]) != masks[m][0]
1360 || (s->sh_flags & masks[m][1])
1361 || s->sh_entsize != ~0UL
1362 || strncmp(secstrings + s->sh_name,
1363 ".init", 5) == 0)
1364 continue;
1365 s->sh_entsize = get_offset(&mod->core_size, s);
1366 DEBUGP("\t%s\n", secstrings + s->sh_name);
1367 }
1368 if (m == 0)
1369 mod->core_text_size = mod->core_size;
1370 }
1371
1372 DEBUGP("Init section allocation order:\n");
1373 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
1374 for (i = 0; i < hdr->e_shnum; ++i) {
1375 Elf_Shdr *s = &sechdrs[i];
1376
1377 if ((s->sh_flags & masks[m][0]) != masks[m][0]
1378 || (s->sh_flags & masks[m][1])
1379 || s->sh_entsize != ~0UL
1380 || strncmp(secstrings + s->sh_name,
1381 ".init", 5) != 0)
1382 continue;
1383 s->sh_entsize = (get_offset(&mod->init_size, s)
1384 | INIT_OFFSET_MASK);
1385 DEBUGP("\t%s\n", secstrings + s->sh_name);
1386 }
1387 if (m == 0)
1388 mod->init_text_size = mod->init_size;
1389 }
1390 }
1391
1392 static void set_license(struct module *mod, const char *license)
1393 {
1394 if (!license)
1395 license = "unspecified";
1396
1397 if (!license_is_gpl_compatible(license)) {
1398 if (!(tainted & TAINT_PROPRIETARY_MODULE))
1399 printk(KERN_WARNING "%s: module license '%s' taints "
1400 "kernel.\n", mod->name, license);
1401 add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
1402 }
1403 }
1404
1405 /* Parse tag=value strings from .modinfo section */
1406 static char *next_string(char *string, unsigned long *secsize)
1407 {
1408 /* Skip non-zero chars */
1409 while (string[0]) {
1410 string++;
1411 if ((*secsize)-- <= 1)
1412 return NULL;
1413 }
1414
1415 /* Skip any zero padding. */
1416 while (!string[0]) {
1417 string++;
1418 if ((*secsize)-- <= 1)
1419 return NULL;
1420 }
1421 return string;
1422 }
1423
1424 static char *get_modinfo(Elf_Shdr *sechdrs,
1425 unsigned int info,
1426 const char *tag)
1427 {
1428 char *p;
1429 unsigned int taglen = strlen(tag);
1430 unsigned long size = sechdrs[info].sh_size;
1431
1432 for (p = (char *)sechdrs[info].sh_addr; p; p = next_string(p, &size)) {
1433 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
1434 return p + taglen + 1;
1435 }
1436 return NULL;
1437 }
1438
1439 static void setup_modinfo(struct module *mod, Elf_Shdr *sechdrs,
1440 unsigned int infoindex)
1441 {
1442 struct module_attribute *attr;
1443 int i;
1444
1445 for (i = 0; (attr = modinfo_attrs[i]); i++) {
1446 if (attr->setup)
1447 attr->setup(mod,
1448 get_modinfo(sechdrs,
1449 infoindex,
1450 attr->attr.name));
1451 }
1452 }
1453
1454 #ifdef CONFIG_KALLSYMS
1455 int is_exported(const char *name, const struct module *mod)
1456 {
1457 if (!mod && lookup_symbol(name, __start___ksymtab, __stop___ksymtab))
1458 return 1;
1459 else
1460 if (mod && lookup_symbol(name, mod->syms, mod->syms + mod->num_syms))
1461 return 1;
1462 else
1463 return 0;
1464 }
1465
1466 /* As per nm */
1467 static char elf_type(const Elf_Sym *sym,
1468 Elf_Shdr *sechdrs,
1469 const char *secstrings,
1470 struct module *mod)
1471 {
1472 if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
1473 if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
1474 return 'v';
1475 else
1476 return 'w';
1477 }
1478 if (sym->st_shndx == SHN_UNDEF)
1479 return 'U';
1480 if (sym->st_shndx == SHN_ABS)
1481 return 'a';
1482 if (sym->st_shndx >= SHN_LORESERVE)
1483 return '?';
1484 if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
1485 return 't';
1486 if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
1487 && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
1488 if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
1489 return 'r';
1490 else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
1491 return 'g';
1492 else
1493 return 'd';
1494 }
1495 if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
1496 if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
1497 return 's';
1498 else
1499 return 'b';
1500 }
1501 if (strncmp(secstrings + sechdrs[sym->st_shndx].sh_name,
1502 ".debug", strlen(".debug")) == 0)
1503 return 'n';
1504 return '?';
1505 }
1506
1507 static void add_kallsyms(struct module *mod,
1508 Elf_Shdr *sechdrs,
1509 unsigned int symindex,
1510 unsigned int strindex,
1511 const char *secstrings)
1512 {
1513 unsigned int i;
1514
1515 mod->symtab = (void *)sechdrs[symindex].sh_addr;
1516 mod->num_symtab = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
1517 mod->strtab = (void *)sechdrs[strindex].sh_addr;
1518
1519 /* Set types up while we still have access to sections. */
1520 for (i = 0; i < mod->num_symtab; i++)
1521 mod->symtab[i].st_info
1522 = elf_type(&mod->symtab[i], sechdrs, secstrings, mod);
1523 }
1524 #else
1525 static inline void add_kallsyms(struct module *mod,
1526 Elf_Shdr *sechdrs,
1527 unsigned int symindex,
1528 unsigned int strindex,
1529 const char *secstrings)
1530 {
1531 }
1532 #endif /* CONFIG_KALLSYMS */
1533
1534 /* Allocate and load the module: note that size of section 0 is always
1535 zero, and we rely on this for optional sections. */
1536 static struct module *load_module(void __user *umod,
1537 unsigned long len,
1538 const char __user *uargs)
1539 {
1540 Elf_Ehdr *hdr;
1541 Elf_Shdr *sechdrs;
1542 char *secstrings, *args, *modmagic, *strtab = NULL;
1543 unsigned int i;
1544 unsigned int symindex = 0;
1545 unsigned int strindex = 0;
1546 unsigned int setupindex;
1547 unsigned int exindex;
1548 unsigned int exportindex;
1549 unsigned int modindex;
1550 unsigned int obsparmindex;
1551 unsigned int infoindex;
1552 unsigned int gplindex;
1553 unsigned int crcindex;
1554 unsigned int gplcrcindex;
1555 unsigned int versindex;
1556 unsigned int pcpuindex;
1557 unsigned int gplfutureindex;
1558 unsigned int gplfuturecrcindex;
1559 unsigned int unwindex = 0;
1560 unsigned int unusedindex;
1561 unsigned int unusedcrcindex;
1562 unsigned int unusedgplindex;
1563 unsigned int unusedgplcrcindex;
1564 struct module *mod;
1565 long err = 0;
1566 void *percpu = NULL, *ptr = NULL; /* Stops spurious gcc warning */
1567 struct exception_table_entry *extable;
1568 mm_segment_t old_fs;
1569
1570 DEBUGP("load_module: umod=%p, len=%lu, uargs=%p\n",
1571 umod, len, uargs);
1572 if (len < sizeof(*hdr))
1573 return ERR_PTR(-ENOEXEC);
1574
1575 /* Suck in entire file: we'll want most of it. */
1576 /* vmalloc barfs on "unusual" numbers. Check here */
1577 if (len > 64 * 1024 * 1024 || (hdr = vmalloc(len)) == NULL)
1578 return ERR_PTR(-ENOMEM);
1579 if (copy_from_user(hdr, umod, len) != 0) {
1580 err = -EFAULT;
1581 goto free_hdr;
1582 }
1583
1584 /* Sanity checks against insmoding binaries or wrong arch,
1585 weird elf version */
1586 if (memcmp(hdr->e_ident, ELFMAG, 4) != 0
1587 || hdr->e_type != ET_REL
1588 || !elf_check_arch(hdr)
1589 || hdr->e_shentsize != sizeof(*sechdrs)) {
1590 err = -ENOEXEC;
1591 goto free_hdr;
1592 }
1593
1594 if (len < hdr->e_shoff + hdr->e_shnum * sizeof(Elf_Shdr))
1595 goto truncated;
1596
1597 /* Convenience variables */
1598 sechdrs = (void *)hdr + hdr->e_shoff;
1599 secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
1600 sechdrs[0].sh_addr = 0;
1601
1602 for (i = 1; i < hdr->e_shnum; i++) {
1603 if (sechdrs[i].sh_type != SHT_NOBITS
1604 && len < sechdrs[i].sh_offset + sechdrs[i].sh_size)
1605 goto truncated;
1606
1607 /* Mark all sections sh_addr with their address in the
1608 temporary image. */
1609 sechdrs[i].sh_addr = (size_t)hdr + sechdrs[i].sh_offset;
1610
1611 /* Internal symbols and strings. */
1612 if (sechdrs[i].sh_type == SHT_SYMTAB) {
1613 symindex = i;
1614 strindex = sechdrs[i].sh_link;
1615 strtab = (char *)hdr + sechdrs[strindex].sh_offset;
1616 }
1617 #ifndef CONFIG_MODULE_UNLOAD
1618 /* Don't load .exit sections */
1619 if (strncmp(secstrings+sechdrs[i].sh_name, ".exit", 5) == 0)
1620 sechdrs[i].sh_flags &= ~(unsigned long)SHF_ALLOC;
1621 #endif
1622 }
1623
1624 modindex = find_sec(hdr, sechdrs, secstrings,
1625 ".gnu.linkonce.this_module");
1626 if (!modindex) {
1627 printk(KERN_WARNING "No module found in object\n");
1628 err = -ENOEXEC;
1629 goto free_hdr;
1630 }
1631 mod = (void *)sechdrs[modindex].sh_addr;
1632
1633 if (symindex == 0) {
1634 printk(KERN_WARNING "%s: module has no symbols (stripped?)\n",
1635 mod->name);
1636 err = -ENOEXEC;
1637 goto free_hdr;
1638 }
1639
1640 /* Optional sections */
1641 exportindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab");
1642 gplindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_gpl");
1643 gplfutureindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_gpl_future");
1644 unusedindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_unused");
1645 unusedgplindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_unused_gpl");
1646 crcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab");
1647 gplcrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_gpl");
1648 gplfuturecrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_gpl_future");
1649 unusedcrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_unused");
1650 unusedgplcrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_unused_gpl");
1651 setupindex = find_sec(hdr, sechdrs, secstrings, "__param");
1652 exindex = find_sec(hdr, sechdrs, secstrings, "__ex_table");
1653 obsparmindex = find_sec(hdr, sechdrs, secstrings, "__obsparm");
1654 versindex = find_sec(hdr, sechdrs, secstrings, "__versions");
1655 infoindex = find_sec(hdr, sechdrs, secstrings, ".modinfo");
1656 pcpuindex = find_pcpusec(hdr, sechdrs, secstrings);
1657 #ifdef ARCH_UNWIND_SECTION_NAME
1658 unwindex = find_sec(hdr, sechdrs, secstrings, ARCH_UNWIND_SECTION_NAME);
1659 #endif
1660
1661 /* Don't keep modinfo section */
1662 sechdrs[infoindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
1663 #ifdef CONFIG_KALLSYMS
1664 /* Keep symbol and string tables for decoding later. */
1665 sechdrs[symindex].sh_flags |= SHF_ALLOC;
1666 sechdrs[strindex].sh_flags |= SHF_ALLOC;
1667 #endif
1668 if (unwindex)
1669 sechdrs[unwindex].sh_flags |= SHF_ALLOC;
1670
1671 /* Check module struct version now, before we try to use module. */
1672 if (!check_modstruct_version(sechdrs, versindex, mod)) {
1673 err = -ENOEXEC;
1674 goto free_hdr;
1675 }
1676
1677 modmagic = get_modinfo(sechdrs, infoindex, "vermagic");
1678 /* This is allowed: modprobe --force will invalidate it. */
1679 if (!modmagic) {
1680 add_taint_module(mod, TAINT_FORCED_MODULE);
1681 printk(KERN_WARNING "%s: no version magic, tainting kernel.\n",
1682 mod->name);
1683 } else if (!same_magic(modmagic, vermagic)) {
1684 printk(KERN_ERR "%s: version magic '%s' should be '%s'\n",
1685 mod->name, modmagic, vermagic);
1686 err = -ENOEXEC;
1687 goto free_hdr;
1688 }
1689
1690 /* Now copy in args */
1691 args = strndup_user(uargs, ~0UL >> 1);
1692 if (IS_ERR(args)) {
1693 err = PTR_ERR(args);
1694 goto free_hdr;
1695 }
1696
1697 if (find_module(mod->name)) {
1698 err = -EEXIST;
1699 goto free_mod;
1700 }
1701
1702 mod->state = MODULE_STATE_COMING;
1703
1704 /* Allow arches to frob section contents and sizes. */
1705 err = module_frob_arch_sections(hdr, sechdrs, secstrings, mod);
1706 if (err < 0)
1707 goto free_mod;
1708
1709 if (pcpuindex) {
1710 /* We have a special allocation for this section. */
1711 percpu = percpu_modalloc(sechdrs[pcpuindex].sh_size,
1712 sechdrs[pcpuindex].sh_addralign,
1713 mod->name);
1714 if (!percpu) {
1715 err = -ENOMEM;
1716 goto free_mod;
1717 }
1718 sechdrs[pcpuindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
1719 mod->percpu = percpu;
1720 }
1721
1722 /* Determine total sizes, and put offsets in sh_entsize. For now
1723 this is done generically; there doesn't appear to be any
1724 special cases for the architectures. */
1725 layout_sections(mod, hdr, sechdrs, secstrings);
1726
1727 /* Do the allocs. */
1728 ptr = module_alloc(mod->core_size);
1729 if (!ptr) {
1730 err = -ENOMEM;
1731 goto free_percpu;
1732 }
1733 memset(ptr, 0, mod->core_size);
1734 mod->module_core = ptr;
1735
1736 ptr = module_alloc(mod->init_size);
1737 if (!ptr && mod->init_size) {
1738 err = -ENOMEM;
1739 goto free_core;
1740 }
1741 memset(ptr, 0, mod->init_size);
1742 mod->module_init = ptr;
1743
1744 /* Transfer each section which specifies SHF_ALLOC */
1745 DEBUGP("final section addresses:\n");
1746 for (i = 0; i < hdr->e_shnum; i++) {
1747 void *dest;
1748
1749 if (!(sechdrs[i].sh_flags & SHF_ALLOC))
1750 continue;
1751
1752 if (sechdrs[i].sh_entsize & INIT_OFFSET_MASK)
1753 dest = mod->module_init
1754 + (sechdrs[i].sh_entsize & ~INIT_OFFSET_MASK);
1755 else
1756 dest = mod->module_core + sechdrs[i].sh_entsize;
1757
1758 if (sechdrs[i].sh_type != SHT_NOBITS)
1759 memcpy(dest, (void *)sechdrs[i].sh_addr,
1760 sechdrs[i].sh_size);
1761 /* Update sh_addr to point to copy in image. */
1762 sechdrs[i].sh_addr = (unsigned long)dest;
1763 DEBUGP("\t0x%lx %s\n", sechdrs[i].sh_addr, secstrings + sechdrs[i].sh_name);
1764 }
1765 /* Module has been moved. */
1766 mod = (void *)sechdrs[modindex].sh_addr;
1767
1768 /* Now we've moved module, initialize linked lists, etc. */
1769 module_unload_init(mod);
1770
1771 /* Set up license info based on the info section */
1772 set_license(mod, get_modinfo(sechdrs, infoindex, "license"));
1773
1774 if (strcmp(mod->name, "ndiswrapper") == 0)
1775 add_taint(TAINT_PROPRIETARY_MODULE);
1776 if (strcmp(mod->name, "driverloader") == 0)
1777 add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
1778
1779 /* Set up MODINFO_ATTR fields */
1780 setup_modinfo(mod, sechdrs, infoindex);
1781
1782 /* Fix up syms, so that st_value is a pointer to location. */
1783 err = simplify_symbols(sechdrs, symindex, strtab, versindex, pcpuindex,
1784 mod);
1785 if (err < 0)
1786 goto cleanup;
1787
1788 /* Set up EXPORTed & EXPORT_GPLed symbols (section 0 is 0 length) */
1789 mod->num_syms = sechdrs[exportindex].sh_size / sizeof(*mod->syms);
1790 mod->syms = (void *)sechdrs[exportindex].sh_addr;
1791 if (crcindex)
1792 mod->crcs = (void *)sechdrs[crcindex].sh_addr;
1793 mod->num_gpl_syms = sechdrs[gplindex].sh_size / sizeof(*mod->gpl_syms);
1794 mod->gpl_syms = (void *)sechdrs[gplindex].sh_addr;
1795 if (gplcrcindex)
1796 mod->gpl_crcs = (void *)sechdrs[gplcrcindex].sh_addr;
1797 mod->num_gpl_future_syms = sechdrs[gplfutureindex].sh_size /
1798 sizeof(*mod->gpl_future_syms);
1799 mod->num_unused_syms = sechdrs[unusedindex].sh_size /
1800 sizeof(*mod->unused_syms);
1801 mod->num_unused_gpl_syms = sechdrs[unusedgplindex].sh_size /
1802 sizeof(*mod->unused_gpl_syms);
1803 mod->gpl_future_syms = (void *)sechdrs[gplfutureindex].sh_addr;
1804 if (gplfuturecrcindex)
1805 mod->gpl_future_crcs = (void *)sechdrs[gplfuturecrcindex].sh_addr;
1806
1807 mod->unused_syms = (void *)sechdrs[unusedindex].sh_addr;
1808 if (unusedcrcindex)
1809 mod->unused_crcs = (void *)sechdrs[unusedcrcindex].sh_addr;
1810 mod->unused_gpl_syms = (void *)sechdrs[unusedgplindex].sh_addr;
1811 if (unusedgplcrcindex)
1812 mod->unused_crcs = (void *)sechdrs[unusedgplcrcindex].sh_addr;
1813
1814 #ifdef CONFIG_MODVERSIONS
1815 if ((mod->num_syms && !crcindex) ||
1816 (mod->num_gpl_syms && !gplcrcindex) ||
1817 (mod->num_gpl_future_syms && !gplfuturecrcindex) ||
1818 (mod->num_unused_syms && !unusedcrcindex) ||
1819 (mod->num_unused_gpl_syms && !unusedgplcrcindex)) {
1820 printk(KERN_WARNING "%s: No versions for exported symbols."
1821 " Tainting kernel.\n", mod->name);
1822 add_taint_module(mod, TAINT_FORCED_MODULE);
1823 }
1824 #endif
1825
1826 /* Now do relocations. */
1827 for (i = 1; i < hdr->e_shnum; i++) {
1828 const char *strtab = (char *)sechdrs[strindex].sh_addr;
1829 unsigned int info = sechdrs[i].sh_info;
1830
1831 /* Not a valid relocation section? */
1832 if (info >= hdr->e_shnum)
1833 continue;
1834
1835 /* Don't bother with non-allocated sections */
1836 if (!(sechdrs[info].sh_flags & SHF_ALLOC))
1837 continue;
1838
1839 if (sechdrs[i].sh_type == SHT_REL)
1840 err = apply_relocate(sechdrs, strtab, symindex, i,mod);
1841 else if (sechdrs[i].sh_type == SHT_RELA)
1842 err = apply_relocate_add(sechdrs, strtab, symindex, i,
1843 mod);
1844 if (err < 0)
1845 goto cleanup;
1846 }
1847
1848 /* Find duplicate symbols */
1849 err = verify_export_symbols(mod);
1850
1851 if (err < 0)
1852 goto cleanup;
1853
1854 /* Set up and sort exception table */
1855 mod->num_exentries = sechdrs[exindex].sh_size / sizeof(*mod->extable);
1856 mod->extable = extable = (void *)sechdrs[exindex].sh_addr;
1857 sort_extable(extable, extable + mod->num_exentries);
1858
1859 /* Finally, copy percpu area over. */
1860 percpu_modcopy(mod->percpu, (void *)sechdrs[pcpuindex].sh_addr,
1861 sechdrs[pcpuindex].sh_size);
1862
1863 add_kallsyms(mod, sechdrs, symindex, strindex, secstrings);
1864
1865 err = module_finalize(hdr, sechdrs, mod);
1866 if (err < 0)
1867 goto cleanup;
1868
1869 /* flush the icache in correct context */
1870 old_fs = get_fs();
1871 set_fs(KERNEL_DS);
1872
1873 /*
1874 * Flush the instruction cache, since we've played with text.
1875 * Do it before processing of module parameters, so the module
1876 * can provide parameter accessor functions of its own.
1877 */
1878 if (mod->module_init)
1879 flush_icache_range((unsigned long)mod->module_init,
1880 (unsigned long)mod->module_init
1881 + mod->init_size);
1882 flush_icache_range((unsigned long)mod->module_core,
1883 (unsigned long)mod->module_core + mod->core_size);
1884
1885 set_fs(old_fs);
1886
1887 mod->args = args;
1888 if (obsparmindex)
1889 printk(KERN_WARNING "%s: Ignoring obsolete parameters\n",
1890 mod->name);
1891
1892 /* Size of section 0 is 0, so this works well if no params */
1893 err = parse_args(mod->name, mod->args,
1894 (struct kernel_param *)
1895 sechdrs[setupindex].sh_addr,
1896 sechdrs[setupindex].sh_size
1897 / sizeof(struct kernel_param),
1898 NULL);
1899 if (err < 0)
1900 goto arch_cleanup;
1901
1902 err = mod_sysfs_setup(mod,
1903 (struct kernel_param *)
1904 sechdrs[setupindex].sh_addr,
1905 sechdrs[setupindex].sh_size
1906 / sizeof(struct kernel_param));
1907 if (err < 0)
1908 goto arch_cleanup;
1909 add_sect_attrs(mod, hdr->e_shnum, secstrings, sechdrs);
1910
1911 /* Size of section 0 is 0, so this works well if no unwind info. */
1912 mod->unwind_info = unwind_add_table(mod,
1913 (void *)sechdrs[unwindex].sh_addr,
1914 sechdrs[unwindex].sh_size);
1915
1916 /* Get rid of temporary copy */
1917 vfree(hdr);
1918
1919 /* Done! */
1920 return mod;
1921
1922 arch_cleanup:
1923 module_arch_cleanup(mod);
1924 cleanup:
1925 module_unload_free(mod);
1926 module_free(mod, mod->module_init);
1927 free_core:
1928 module_free(mod, mod->module_core);
1929 free_percpu:
1930 if (percpu)
1931 percpu_modfree(percpu);
1932 free_mod:
1933 kfree(args);
1934 free_hdr:
1935 vfree(hdr);
1936 return ERR_PTR(err);
1937
1938 truncated:
1939 printk(KERN_ERR "Module len %lu truncated\n", len);
1940 err = -ENOEXEC;
1941 goto free_hdr;
1942 }
1943
1944 /*
1945 * link the module with the whole machine is stopped with interrupts off
1946 * - this defends against kallsyms not taking locks
1947 */
1948 static int __link_module(void *_mod)
1949 {
1950 struct module *mod = _mod;
1951 list_add(&mod->list, &modules);
1952 return 0;
1953 }
1954
1955 /* This is where the real work happens */
1956 asmlinkage long
1957 sys_init_module(void __user *umod,
1958 unsigned long len,
1959 const char __user *uargs)
1960 {
1961 struct module *mod;
1962 int ret = 0;
1963
1964 /* Must have permission */
1965 if (!capable(CAP_SYS_MODULE))
1966 return -EPERM;
1967
1968 /* Only one module load at a time, please */
1969 if (mutex_lock_interruptible(&module_mutex) != 0)
1970 return -EINTR;
1971
1972 /* Do all the hard work */
1973 mod = load_module(umod, len, uargs);
1974 if (IS_ERR(mod)) {
1975 mutex_unlock(&module_mutex);
1976 return PTR_ERR(mod);
1977 }
1978
1979 /* Now sew it into the lists. They won't access us, since
1980 strong_try_module_get() will fail. */
1981 stop_machine_run(__link_module, mod, NR_CPUS);
1982
1983 /* Drop lock so they can recurse */
1984 mutex_unlock(&module_mutex);
1985
1986 blocking_notifier_call_chain(&module_notify_list,
1987 MODULE_STATE_COMING, mod);
1988
1989 /* Start the module */
1990 if (mod->init != NULL)
1991 ret = mod->init();
1992 if (ret < 0) {
1993 /* Init routine failed: abort. Try to protect us from
1994 buggy refcounters. */
1995 mod->state = MODULE_STATE_GOING;
1996 synchronize_sched();
1997 if (mod->unsafe)
1998 printk(KERN_ERR "%s: module is now stuck!\n",
1999 mod->name);
2000 else {
2001 module_put(mod);
2002 mutex_lock(&module_mutex);
2003 free_module(mod);
2004 mutex_unlock(&module_mutex);
2005 }
2006 return ret;
2007 }
2008
2009 /* Now it's a first class citizen! */
2010 mutex_lock(&module_mutex);
2011 mod->state = MODULE_STATE_LIVE;
2012 /* Drop initial reference. */
2013 module_put(mod);
2014 unwind_remove_table(mod->unwind_info, 1);
2015 module_free(mod, mod->module_init);
2016 mod->module_init = NULL;
2017 mod->init_size = 0;
2018 mod->init_text_size = 0;
2019 mutex_unlock(&module_mutex);
2020
2021 return 0;
2022 }
2023
2024 static inline int within(unsigned long addr, void *start, unsigned long size)
2025 {
2026 return ((void *)addr >= start && (void *)addr < start + size);
2027 }
2028
2029 #ifdef CONFIG_KALLSYMS
2030 /*
2031 * This ignores the intensely annoying "mapping symbols" found
2032 * in ARM ELF files: $a, $t and $d.
2033 */
2034 static inline int is_arm_mapping_symbol(const char *str)
2035 {
2036 return str[0] == '$' && strchr("atd", str[1])
2037 && (str[2] == '\0' || str[2] == '.');
2038 }
2039
2040 static const char *get_ksymbol(struct module *mod,
2041 unsigned long addr,
2042 unsigned long *size,
2043 unsigned long *offset)
2044 {
2045 unsigned int i, best = 0;
2046 unsigned long nextval;
2047
2048 /* At worse, next value is at end of module */
2049 if (within(addr, mod->module_init, mod->init_size))
2050 nextval = (unsigned long)mod->module_init+mod->init_text_size;
2051 else
2052 nextval = (unsigned long)mod->module_core+mod->core_text_size;
2053
2054 /* Scan for closest preceeding symbol, and next symbol. (ELF
2055 starts real symbols at 1). */
2056 for (i = 1; i < mod->num_symtab; i++) {
2057 if (mod->symtab[i].st_shndx == SHN_UNDEF)
2058 continue;
2059
2060 /* We ignore unnamed symbols: they're uninformative
2061 * and inserted at a whim. */
2062 if (mod->symtab[i].st_value <= addr
2063 && mod->symtab[i].st_value > mod->symtab[best].st_value
2064 && *(mod->strtab + mod->symtab[i].st_name) != '\0'
2065 && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
2066 best = i;
2067 if (mod->symtab[i].st_value > addr
2068 && mod->symtab[i].st_value < nextval
2069 && *(mod->strtab + mod->symtab[i].st_name) != '\0'
2070 && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
2071 nextval = mod->symtab[i].st_value;
2072 }
2073
2074 if (!best)
2075 return NULL;
2076
2077 *size = nextval - mod->symtab[best].st_value;
2078 *offset = addr - mod->symtab[best].st_value;
2079 return mod->strtab + mod->symtab[best].st_name;
2080 }
2081
2082 /* For kallsyms to ask for address resolution. NULL means not found.
2083 We don't lock, as this is used for oops resolution and races are a
2084 lesser concern. */
2085 const char *module_address_lookup(unsigned long addr,
2086 unsigned long *size,
2087 unsigned long *offset,
2088 char **modname)
2089 {
2090 struct module *mod;
2091
2092 list_for_each_entry(mod, &modules, list) {
2093 if (within(addr, mod->module_init, mod->init_size)
2094 || within(addr, mod->module_core, mod->core_size)) {
2095 if (modname)
2096 *modname = mod->name;
2097 return get_ksymbol(mod, addr, size, offset);
2098 }
2099 }
2100 return NULL;
2101 }
2102
2103 struct module *module_get_kallsym(unsigned int symnum, unsigned long *value,
2104 char *type, char *name, size_t namelen)
2105 {
2106 struct module *mod;
2107
2108 mutex_lock(&module_mutex);
2109 list_for_each_entry(mod, &modules, list) {
2110 if (symnum < mod->num_symtab) {
2111 *value = mod->symtab[symnum].st_value;
2112 *type = mod->symtab[symnum].st_info;
2113 strlcpy(name, mod->strtab + mod->symtab[symnum].st_name,
2114 namelen);
2115 mutex_unlock(&module_mutex);
2116 return mod;
2117 }
2118 symnum -= mod->num_symtab;
2119 }
2120 mutex_unlock(&module_mutex);
2121 return NULL;
2122 }
2123
2124 static unsigned long mod_find_symname(struct module *mod, const char *name)
2125 {
2126 unsigned int i;
2127
2128 for (i = 0; i < mod->num_symtab; i++)
2129 if (strcmp(name, mod->strtab+mod->symtab[i].st_name) == 0 &&
2130 mod->symtab[i].st_info != 'U')
2131 return mod->symtab[i].st_value;
2132 return 0;
2133 }
2134
2135 /* Look for this name: can be of form module:name. */
2136 unsigned long module_kallsyms_lookup_name(const char *name)
2137 {
2138 struct module *mod;
2139 char *colon;
2140 unsigned long ret = 0;
2141
2142 /* Don't lock: we're in enough trouble already. */
2143 if ((colon = strchr(name, ':')) != NULL) {
2144 *colon = '\0';
2145 if ((mod = find_module(name)) != NULL)
2146 ret = mod_find_symname(mod, colon+1);
2147 *colon = ':';
2148 } else {
2149 list_for_each_entry(mod, &modules, list)
2150 if ((ret = mod_find_symname(mod, name)) != 0)
2151 break;
2152 }
2153 return ret;
2154 }
2155 #endif /* CONFIG_KALLSYMS */
2156
2157 /* Called by the /proc file system to return a list of modules. */
2158 static void *m_start(struct seq_file *m, loff_t *pos)
2159 {
2160 struct list_head *i;
2161 loff_t n = 0;
2162
2163 mutex_lock(&module_mutex);
2164 list_for_each(i, &modules) {
2165 if (n++ == *pos)
2166 break;
2167 }
2168 if (i == &modules)
2169 return NULL;
2170 return i;
2171 }
2172
2173 static void *m_next(struct seq_file *m, void *p, loff_t *pos)
2174 {
2175 struct list_head *i = p;
2176 (*pos)++;
2177 if (i->next == &modules)
2178 return NULL;
2179 return i->next;
2180 }
2181
2182 static void m_stop(struct seq_file *m, void *p)
2183 {
2184 mutex_unlock(&module_mutex);
2185 }
2186
2187 static char *taint_flags(unsigned int taints, char *buf)
2188 {
2189 int bx = 0;
2190
2191 if (taints) {
2192 buf[bx++] = '(';
2193 if (taints & TAINT_PROPRIETARY_MODULE)
2194 buf[bx++] = 'P';
2195 if (taints & TAINT_FORCED_MODULE)
2196 buf[bx++] = 'F';
2197 /*
2198 * TAINT_FORCED_RMMOD: could be added.
2199 * TAINT_UNSAFE_SMP, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't
2200 * apply to modules.
2201 */
2202 buf[bx++] = ')';
2203 }
2204 buf[bx] = '\0';
2205
2206 return buf;
2207 }
2208
2209 static int m_show(struct seq_file *m, void *p)
2210 {
2211 struct module *mod = list_entry(p, struct module, list);
2212 char buf[8];
2213
2214 seq_printf(m, "%s %lu",
2215 mod->name, mod->init_size + mod->core_size);
2216 print_unload_info(m, mod);
2217
2218 /* Informative for users. */
2219 seq_printf(m, " %s",
2220 mod->state == MODULE_STATE_GOING ? "Unloading":
2221 mod->state == MODULE_STATE_COMING ? "Loading":
2222 "Live");
2223 /* Used by oprofile and other similar tools. */
2224 seq_printf(m, " 0x%p", mod->module_core);
2225
2226 /* Taints info */
2227 if (mod->taints)
2228 seq_printf(m, " %s", taint_flags(mod->taints, buf));
2229
2230 seq_printf(m, "\n");
2231 return 0;
2232 }
2233
2234 /* Format: modulename size refcount deps address
2235
2236 Where refcount is a number or -, and deps is a comma-separated list
2237 of depends or -.
2238 */
2239 const struct seq_operations modules_op = {
2240 .start = m_start,
2241 .next = m_next,
2242 .stop = m_stop,
2243 .show = m_show
2244 };
2245
2246 /* Given an address, look for it in the module exception tables. */
2247 const struct exception_table_entry *search_module_extables(unsigned long addr)
2248 {
2249 unsigned long flags;
2250 const struct exception_table_entry *e = NULL;
2251 struct module *mod;
2252
2253 spin_lock_irqsave(&modlist_lock, flags);
2254 list_for_each_entry(mod, &modules, list) {
2255 if (mod->num_exentries == 0)
2256 continue;
2257
2258 e = search_extable(mod->extable,
2259 mod->extable + mod->num_exentries - 1,
2260 addr);
2261 if (e)
2262 break;
2263 }
2264 spin_unlock_irqrestore(&modlist_lock, flags);
2265
2266 /* Now, if we found one, we are running inside it now, hence
2267 we cannot unload the module, hence no refcnt needed. */
2268 return e;
2269 }
2270
2271 /*
2272 * Is this a valid module address?
2273 */
2274 int is_module_address(unsigned long addr)
2275 {
2276 unsigned long flags;
2277 struct module *mod;
2278
2279 spin_lock_irqsave(&modlist_lock, flags);
2280
2281 list_for_each_entry(mod, &modules, list) {
2282 if (within(addr, mod->module_core, mod->core_size)) {
2283 spin_unlock_irqrestore(&modlist_lock, flags);
2284 return 1;
2285 }
2286 }
2287
2288 spin_unlock_irqrestore(&modlist_lock, flags);
2289
2290 return 0;
2291 }
2292
2293
2294 /* Is this a valid kernel address? We don't grab the lock: we are oopsing. */
2295 struct module *__module_text_address(unsigned long addr)
2296 {
2297 struct module *mod;
2298
2299 list_for_each_entry(mod, &modules, list)
2300 if (within(addr, mod->module_init, mod->init_text_size)
2301 || within(addr, mod->module_core, mod->core_text_size))
2302 return mod;
2303 return NULL;
2304 }
2305
2306 struct module *module_text_address(unsigned long addr)
2307 {
2308 struct module *mod;
2309 unsigned long flags;
2310
2311 spin_lock_irqsave(&modlist_lock, flags);
2312 mod = __module_text_address(addr);
2313 spin_unlock_irqrestore(&modlist_lock, flags);
2314
2315 return mod;
2316 }
2317
2318 /* Don't grab lock, we're oopsing. */
2319 void print_modules(void)
2320 {
2321 struct module *mod;
2322 char buf[8];
2323
2324 printk("Modules linked in:");
2325 list_for_each_entry(mod, &modules, list)
2326 printk(" %s%s", mod->name, taint_flags(mod->taints, buf));
2327 printk("\n");
2328 }
2329
2330 static char *make_driver_name(struct device_driver *drv)
2331 {
2332 char *driver_name;
2333
2334 driver_name = kmalloc(strlen(drv->name) + strlen(drv->bus->name) + 2,
2335 GFP_KERNEL);
2336 if (!driver_name)
2337 return NULL;
2338
2339 sprintf(driver_name, "%s:%s", drv->bus->name, drv->name);
2340 return driver_name;
2341 }
2342
2343 void module_add_driver(struct module *mod, struct device_driver *drv)
2344 {
2345 char *driver_name;
2346 int no_warn;
2347
2348 if (!mod || !drv)
2349 return;
2350
2351 /* Don't check return codes; these calls are idempotent */
2352 no_warn = sysfs_create_link(&drv->kobj, &mod->mkobj.kobj, "module");
2353 driver_name = make_driver_name(drv);
2354 if (driver_name) {
2355 no_warn = sysfs_create_link(mod->drivers_dir, &drv->kobj,
2356 driver_name);
2357 kfree(driver_name);
2358 }
2359 }
2360 EXPORT_SYMBOL(module_add_driver);
2361
2362 void module_remove_driver(struct device_driver *drv)
2363 {
2364 char *driver_name;
2365
2366 if (!drv)
2367 return;
2368
2369 sysfs_remove_link(&drv->kobj, "module");
2370 if (drv->owner && drv->owner->drivers_dir) {
2371 driver_name = make_driver_name(drv);
2372 if (driver_name) {
2373 sysfs_remove_link(drv->owner->drivers_dir,
2374 driver_name);
2375 kfree(driver_name);
2376 }
2377 }
2378 }
2379 EXPORT_SYMBOL(module_remove_driver);
2380
2381 #ifdef CONFIG_MODVERSIONS
2382 /* Generate the signature for struct module here, too, for modversions. */
2383 void struct_module(struct module *mod) { return; }
2384 EXPORT_SYMBOL(struct_module);
2385 #endif
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