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[PATCH] mark struct file_operations const 4
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / kernel / module.c
blob8a94e054230c07abb5371c8e8b4e369f3e8476bd
1 /*
2 Copyright (C) 2002 Richard Henderson
3 Copyright (C) 2001 Rusty Russell, 2002 Rusty Russell IBM.
4
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 2 of the License, or
8 (at your option) any later version.
9
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
14
15 You should have received a copy of the GNU General Public License
16 along with this program; if not, write to the Free Software
17 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 */
19 #include <linux/module.h>
20 #include <linux/moduleloader.h>
21 #include <linux/init.h>
22 #include <linux/kernel.h>
23 #include <linux/slab.h>
24 #include <linux/vmalloc.h>
25 #include <linux/elf.h>
26 #include <linux/seq_file.h>
27 #include <linux/syscalls.h>
28 #include <linux/fcntl.h>
29 #include <linux/rcupdate.h>
30 #include <linux/capability.h>
31 #include <linux/cpu.h>
32 #include <linux/moduleparam.h>
33 #include <linux/errno.h>
34 #include <linux/err.h>
35 #include <linux/vermagic.h>
36 #include <linux/notifier.h>
37 #include <linux/sched.h>
38 #include <linux/stop_machine.h>
39 #include <linux/device.h>
40 #include <linux/string.h>
41 #include <linux/mutex.h>
42 #include <linux/unwind.h>
43 #include <asm/uaccess.h>
44 #include <asm/semaphore.h>
45 #include <asm/cacheflush.h>
46 #include <linux/license.h>
47
48 #if 0
49 #define DEBUGP printk
50 #else
51 #define DEBUGP(fmt , a...)
52 #endif
53
54 #ifndef ARCH_SHF_SMALL
55 #define ARCH_SHF_SMALL 0
56 #endif
57
58 /* If this is set, the section belongs in the init part of the module */
59 #define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
60
61 /* Protects module list */
62 static DEFINE_SPINLOCK(modlist_lock);
63
64 /* List of modules, protected by module_mutex AND modlist_lock */
65 static DEFINE_MUTEX(module_mutex);
66 static LIST_HEAD(modules);
67
68 static BLOCKING_NOTIFIER_HEAD(module_notify_list);
69
70 int register_module_notifier(struct notifier_block * nb)
71 {
72 return blocking_notifier_chain_register(&module_notify_list, nb);
73 }
74 EXPORT_SYMBOL(register_module_notifier);
75
76 int unregister_module_notifier(struct notifier_block * nb)
77 {
78 return blocking_notifier_chain_unregister(&module_notify_list, nb);
79 }
80 EXPORT_SYMBOL(unregister_module_notifier);
81
82 /* We require a truly strong try_module_get() */
83 static inline int strong_try_module_get(struct module *mod)
84 {
85 if (mod && mod->state == MODULE_STATE_COMING)
86 return 0;
87 return try_module_get(mod);
88 }
89
90 static inline void add_taint_module(struct module *mod, unsigned flag)
91 {
92 add_taint(flag);
93 mod->taints |= flag;
94 }
95
96 /* A thread that wants to hold a reference to a module only while it
97 * is running can call ths to safely exit.
98 * nfsd and lockd use this.
99 */
100 void __module_put_and_exit(struct module *mod, long code)
101 {
102 module_put(mod);
103 do_exit(code);
104 }
105 EXPORT_SYMBOL(__module_put_and_exit);
106
107 /* Find a module section: 0 means not found. */
108 static unsigned int find_sec(Elf_Ehdr *hdr,
109 Elf_Shdr *sechdrs,
110 const char *secstrings,
111 const char *name)
112 {
113 unsigned int i;
114
115 for (i = 1; i < hdr->e_shnum; i++)
116 /* Alloc bit cleared means "ignore it." */
117 if ((sechdrs[i].sh_flags & SHF_ALLOC)
118 && strcmp(secstrings+sechdrs[i].sh_name, name) == 0)
119 return i;
120 return 0;
121 }
122
123 /* Provided by the linker */
124 extern const struct kernel_symbol __start___ksymtab[];
125 extern const struct kernel_symbol __stop___ksymtab[];
126 extern const struct kernel_symbol __start___ksymtab_gpl[];
127 extern const struct kernel_symbol __stop___ksymtab_gpl[];
128 extern const struct kernel_symbol __start___ksymtab_gpl_future[];
129 extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
130 extern const struct kernel_symbol __start___ksymtab_unused[];
131 extern const struct kernel_symbol __stop___ksymtab_unused[];
132 extern const struct kernel_symbol __start___ksymtab_unused_gpl[];
133 extern const struct kernel_symbol __stop___ksymtab_unused_gpl[];
134 extern const struct kernel_symbol __start___ksymtab_gpl_future[];
135 extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
136 extern const unsigned long __start___kcrctab[];
137 extern const unsigned long __start___kcrctab_gpl[];
138 extern const unsigned long __start___kcrctab_gpl_future[];
139 extern const unsigned long __start___kcrctab_unused[];
140 extern const unsigned long __start___kcrctab_unused_gpl[];
141
142 #ifndef CONFIG_MODVERSIONS
143 #define symversion(base, idx) NULL
144 #else
145 #define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
146 #endif
147
148 /* lookup symbol in given range of kernel_symbols */
149 static const struct kernel_symbol *lookup_symbol(const char *name,
150 const struct kernel_symbol *start,
151 const struct kernel_symbol *stop)
152 {
153 const struct kernel_symbol *ks = start;
154 for (; ks < stop; ks++)
155 if (strcmp(ks->name, name) == 0)
156 return ks;
157 return NULL;
158 }
159
160 static void printk_unused_warning(const char *name)
161 {
162 printk(KERN_WARNING "Symbol %s is marked as UNUSED, "
163 "however this module is using it.\n", name);
164 printk(KERN_WARNING "This symbol will go away in the future.\n");
165 printk(KERN_WARNING "Please evalute if this is the right api to use, "
166 "and if it really is, submit a report the linux kernel "
167 "mailinglist together with submitting your code for "
168 "inclusion.\n");
169 }
170
171 /* Find a symbol, return value, crc and module which owns it */
172 static unsigned long __find_symbol(const char *name,
173 struct module **owner,
174 const unsigned long **crc,
175 int gplok)
176 {
177 struct module *mod;
178 const struct kernel_symbol *ks;
179
180 /* Core kernel first. */
181 *owner = NULL;
182 ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
183 if (ks) {
184 *crc = symversion(__start___kcrctab, (ks - __start___ksymtab));
185 return ks->value;
186 }
187 if (gplok) {
188 ks = lookup_symbol(name, __start___ksymtab_gpl,
189 __stop___ksymtab_gpl);
190 if (ks) {
191 *crc = symversion(__start___kcrctab_gpl,
192 (ks - __start___ksymtab_gpl));
193 return ks->value;
194 }
195 }
196 ks = lookup_symbol(name, __start___ksymtab_gpl_future,
197 __stop___ksymtab_gpl_future);
198 if (ks) {
199 if (!gplok) {
200 printk(KERN_WARNING "Symbol %s is being used "
201 "by a non-GPL module, which will not "
202 "be allowed in the future\n", name);
203 printk(KERN_WARNING "Please see the file "
204 "Documentation/feature-removal-schedule.txt "
205 "in the kernel source tree for more "
206 "details.\n");
207 }
208 *crc = symversion(__start___kcrctab_gpl_future,
209 (ks - __start___ksymtab_gpl_future));
210 return ks->value;
211 }
212
213 ks = lookup_symbol(name, __start___ksymtab_unused,
214 __stop___ksymtab_unused);
215 if (ks) {
216 printk_unused_warning(name);
217 *crc = symversion(__start___kcrctab_unused,
218 (ks - __start___ksymtab_unused));
219 return ks->value;
220 }
221
222 if (gplok)
223 ks = lookup_symbol(name, __start___ksymtab_unused_gpl,
224 __stop___ksymtab_unused_gpl);
225 if (ks) {
226 printk_unused_warning(name);
227 *crc = symversion(__start___kcrctab_unused_gpl,
228 (ks - __start___ksymtab_unused_gpl));
229 return ks->value;
230 }
231
232 /* Now try modules. */
233 list_for_each_entry(mod, &modules, list) {
234 *owner = mod;
235 ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
236 if (ks) {
237 *crc = symversion(mod->crcs, (ks - mod->syms));
238 return ks->value;
239 }
240
241 if (gplok) {
242 ks = lookup_symbol(name, mod->gpl_syms,
243 mod->gpl_syms + mod->num_gpl_syms);
244 if (ks) {
245 *crc = symversion(mod->gpl_crcs,
246 (ks - mod->gpl_syms));
247 return ks->value;
248 }
249 }
250 ks = lookup_symbol(name, mod->unused_syms, mod->unused_syms + mod->num_unused_syms);
251 if (ks) {
252 printk_unused_warning(name);
253 *crc = symversion(mod->unused_crcs, (ks - mod->unused_syms));
254 return ks->value;
255 }
256
257 if (gplok) {
258 ks = lookup_symbol(name, mod->unused_gpl_syms,
259 mod->unused_gpl_syms + mod->num_unused_gpl_syms);
260 if (ks) {
261 printk_unused_warning(name);
262 *crc = symversion(mod->unused_gpl_crcs,
263 (ks - mod->unused_gpl_syms));
264 return ks->value;
265 }
266 }
267 ks = lookup_symbol(name, mod->gpl_future_syms,
268 (mod->gpl_future_syms +
269 mod->num_gpl_future_syms));
270 if (ks) {
271 if (!gplok) {
272 printk(KERN_WARNING "Symbol %s is being used "
273 "by a non-GPL module, which will not "
274 "be allowed in the future\n", name);
275 printk(KERN_WARNING "Please see the file "
276 "Documentation/feature-removal-schedule.txt "
277 "in the kernel source tree for more "
278 "details.\n");
279 }
280 *crc = symversion(mod->gpl_future_crcs,
281 (ks - mod->gpl_future_syms));
282 return ks->value;
283 }
284 }
285 DEBUGP("Failed to find symbol %s\n", name);
286 return 0;
287 }
288
289 /* Search for module by name: must hold module_mutex. */
290 static struct module *find_module(const char *name)
291 {
292 struct module *mod;
293
294 list_for_each_entry(mod, &modules, list) {
295 if (strcmp(mod->name, name) == 0)
296 return mod;
297 }
298 return NULL;
299 }
300
301 #ifdef CONFIG_SMP
302 /* Number of blocks used and allocated. */
303 static unsigned int pcpu_num_used, pcpu_num_allocated;
304 /* Size of each block. -ve means used. */
305 static int *pcpu_size;
306
307 static int split_block(unsigned int i, unsigned short size)
308 {
309 /* Reallocation required? */
310 if (pcpu_num_used + 1 > pcpu_num_allocated) {
311 int *new = kmalloc(sizeof(new[0]) * pcpu_num_allocated*2,
312 GFP_KERNEL);
313 if (!new)
314 return 0;
315
316 memcpy(new, pcpu_size, sizeof(new[0])*pcpu_num_allocated);
317 pcpu_num_allocated *= 2;
318 kfree(pcpu_size);
319 pcpu_size = new;
320 }
321
322 /* Insert a new subblock */
323 memmove(&pcpu_size[i+1], &pcpu_size[i],
324 sizeof(pcpu_size[0]) * (pcpu_num_used - i));
325 pcpu_num_used++;
326
327 pcpu_size[i+1] -= size;
328 pcpu_size[i] = size;
329 return 1;
330 }
331
332 static inline unsigned int block_size(int val)
333 {
334 if (val < 0)
335 return -val;
336 return val;
337 }
338
339 /* Created by linker magic */
340 extern char __per_cpu_start[], __per_cpu_end[];
341
342 static void *percpu_modalloc(unsigned long size, unsigned long align,
343 const char *name)
344 {
345 unsigned long extra;
346 unsigned int i;
347 void *ptr;
348
349 if (align > SMP_CACHE_BYTES) {
350 printk(KERN_WARNING "%s: per-cpu alignment %li > %i\n",
351 name, align, SMP_CACHE_BYTES);
352 align = SMP_CACHE_BYTES;
353 }
354
355 ptr = __per_cpu_start;
356 for (i = 0; i < pcpu_num_used; ptr += block_size(pcpu_size[i]), i++) {
357 /* Extra for alignment requirement. */
358 extra = ALIGN((unsigned long)ptr, align) - (unsigned long)ptr;
359 BUG_ON(i == 0 && extra != 0);
360
361 if (pcpu_size[i] < 0 || pcpu_size[i] < extra + size)
362 continue;
363
364 /* Transfer extra to previous block. */
365 if (pcpu_size[i-1] < 0)
366 pcpu_size[i-1] -= extra;
367 else
368 pcpu_size[i-1] += extra;
369 pcpu_size[i] -= extra;
370 ptr += extra;
371
372 /* Split block if warranted */
373 if (pcpu_size[i] - size > sizeof(unsigned long))
374 if (!split_block(i, size))
375 return NULL;
376
377 /* Mark allocated */
378 pcpu_size[i] = -pcpu_size[i];
379 return ptr;
380 }
381
382 printk(KERN_WARNING "Could not allocate %lu bytes percpu data\n",
383 size);
384 return NULL;
385 }
386
387 static void percpu_modfree(void *freeme)
388 {
389 unsigned int i;
390 void *ptr = __per_cpu_start + block_size(pcpu_size[0]);
391
392 /* First entry is core kernel percpu data. */
393 for (i = 1; i < pcpu_num_used; ptr += block_size(pcpu_size[i]), i++) {
394 if (ptr == freeme) {
395 pcpu_size[i] = -pcpu_size[i];
396 goto free;
397 }
398 }
399 BUG();
400
401 free:
402 /* Merge with previous? */
403 if (pcpu_size[i-1] >= 0) {
404 pcpu_size[i-1] += pcpu_size[i];
405 pcpu_num_used--;
406 memmove(&pcpu_size[i], &pcpu_size[i+1],
407 (pcpu_num_used - i) * sizeof(pcpu_size[0]));
408 i--;
409 }
410 /* Merge with next? */
411 if (i+1 < pcpu_num_used && pcpu_size[i+1] >= 0) {
412 pcpu_size[i] += pcpu_size[i+1];
413 pcpu_num_used--;
414 memmove(&pcpu_size[i+1], &pcpu_size[i+2],
415 (pcpu_num_used - (i+1)) * sizeof(pcpu_size[0]));
416 }
417 }
418
419 static unsigned int find_pcpusec(Elf_Ehdr *hdr,
420 Elf_Shdr *sechdrs,
421 const char *secstrings)
422 {
423 return find_sec(hdr, sechdrs, secstrings, ".data.percpu");
424 }
425
426 static int percpu_modinit(void)
427 {
428 pcpu_num_used = 2;
429 pcpu_num_allocated = 2;
430 pcpu_size = kmalloc(sizeof(pcpu_size[0]) * pcpu_num_allocated,
431 GFP_KERNEL);
432 /* Static in-kernel percpu data (used). */
433 pcpu_size[0] = -ALIGN(__per_cpu_end-__per_cpu_start, SMP_CACHE_BYTES);
434 /* Free room. */
435 pcpu_size[1] = PERCPU_ENOUGH_ROOM + pcpu_size[0];
436 if (pcpu_size[1] < 0) {
437 printk(KERN_ERR "No per-cpu room for modules.\n");
438 pcpu_num_used = 1;
439 }
440
441 return 0;
442 }
443 __initcall(percpu_modinit);
444 #else /* ... !CONFIG_SMP */
445 static inline void *percpu_modalloc(unsigned long size, unsigned long align,
446 const char *name)
447 {
448 return NULL;
449 }
450 static inline void percpu_modfree(void *pcpuptr)
451 {
452 BUG();
453 }
454 static inline unsigned int find_pcpusec(Elf_Ehdr *hdr,
455 Elf_Shdr *sechdrs,
456 const char *secstrings)
457 {
458 return 0;
459 }
460 static inline void percpu_modcopy(void *pcpudst, const void *src,
461 unsigned long size)
462 {
463 /* pcpusec should be 0, and size of that section should be 0. */
464 BUG_ON(size != 0);
465 }
466 #endif /* CONFIG_SMP */
467
468 #define MODINFO_ATTR(field) \
469 static void setup_modinfo_##field(struct module *mod, const char *s) \
470 { \
471 mod->field = kstrdup(s, GFP_KERNEL); \
472 } \
473 static ssize_t show_modinfo_##field(struct module_attribute *mattr, \
474 struct module *mod, char *buffer) \
475 { \
476 return sprintf(buffer, "%s\n", mod->field); \
477 } \
478 static int modinfo_##field##_exists(struct module *mod) \
479 { \
480 return mod->field != NULL; \
481 } \
482 static void free_modinfo_##field(struct module *mod) \
483 { \
484 kfree(mod->field); \
485 mod->field = NULL; \
486 } \
487 static struct module_attribute modinfo_##field = { \
488 .attr = { .name = __stringify(field), .mode = 0444, \
489 .owner = THIS_MODULE }, \
490 .show = show_modinfo_##field, \
491 .setup = setup_modinfo_##field, \
492 .test = modinfo_##field##_exists, \
493 .free = free_modinfo_##field, \
494 };
495
496 MODINFO_ATTR(version);
497 MODINFO_ATTR(srcversion);
498
499 #ifdef CONFIG_MODULE_UNLOAD
500 /* Init the unload section of the module. */
501 static void module_unload_init(struct module *mod)
502 {
503 unsigned int i;
504
505 INIT_LIST_HEAD(&mod->modules_which_use_me);
506 for (i = 0; i < NR_CPUS; i++)
507 local_set(&mod->ref[i].count, 0);
508 /* Hold reference count during initialization. */
509 local_set(&mod->ref[raw_smp_processor_id()].count, 1);
510 /* Backwards compatibility macros put refcount during init. */
511 mod->waiter = current;
512 }
513
514 /* modules using other modules */
515 struct module_use
516 {
517 struct list_head list;
518 struct module *module_which_uses;
519 };
520
521 /* Does a already use b? */
522 static int already_uses(struct module *a, struct module *b)
523 {
524 struct module_use *use;
525
526 list_for_each_entry(use, &b->modules_which_use_me, list) {
527 if (use->module_which_uses == a) {
528 DEBUGP("%s uses %s!\n", a->name, b->name);
529 return 1;
530 }
531 }
532 DEBUGP("%s does not use %s!\n", a->name, b->name);
533 return 0;
534 }
535
536 /* Module a uses b */
537 static int use_module(struct module *a, struct module *b)
538 {
539 struct module_use *use;
540 int no_warn;
541
542 if (b == NULL || already_uses(a, b)) return 1;
543
544 if (!strong_try_module_get(b))
545 return 0;
546
547 DEBUGP("Allocating new usage for %s.\n", a->name);
548 use = kmalloc(sizeof(*use), GFP_ATOMIC);
549 if (!use) {
550 printk("%s: out of memory loading\n", a->name);
551 module_put(b);
552 return 0;
553 }
554
555 use->module_which_uses = a;
556 list_add(&use->list, &b->modules_which_use_me);
557 no_warn = sysfs_create_link(b->holders_dir, &a->mkobj.kobj, a->name);
558 return 1;
559 }
560
561 /* Clear the unload stuff of the module. */
562 static void module_unload_free(struct module *mod)
563 {
564 struct module *i;
565
566 list_for_each_entry(i, &modules, list) {
567 struct module_use *use;
568
569 list_for_each_entry(use, &i->modules_which_use_me, list) {
570 if (use->module_which_uses == mod) {
571 DEBUGP("%s unusing %s\n", mod->name, i->name);
572 module_put(i);
573 list_del(&use->list);
574 kfree(use);
575 sysfs_remove_link(i->holders_dir, mod->name);
576 /* There can be at most one match. */
577 break;
578 }
579 }
580 }
581 }
582
583 #ifdef CONFIG_MODULE_FORCE_UNLOAD
584 static inline int try_force_unload(unsigned int flags)
585 {
586 int ret = (flags & O_TRUNC);
587 if (ret)
588 add_taint(TAINT_FORCED_RMMOD);
589 return ret;
590 }
591 #else
592 static inline int try_force_unload(unsigned int flags)
593 {
594 return 0;
595 }
596 #endif /* CONFIG_MODULE_FORCE_UNLOAD */
597
598 struct stopref
599 {
600 struct module *mod;
601 int flags;
602 int *forced;
603 };
604
605 /* Whole machine is stopped with interrupts off when this runs. */
606 static int __try_stop_module(void *_sref)
607 {
608 struct stopref *sref = _sref;
609
610 /* If it's not unused, quit unless we are told to block. */
611 if ((sref->flags & O_NONBLOCK) && module_refcount(sref->mod) != 0) {
612 if (!(*sref->forced = try_force_unload(sref->flags)))
613 return -EWOULDBLOCK;
614 }
615
616 /* Mark it as dying. */
617 sref->mod->state = MODULE_STATE_GOING;
618 return 0;
619 }
620
621 static int try_stop_module(struct module *mod, int flags, int *forced)
622 {
623 struct stopref sref = { mod, flags, forced };
624
625 return stop_machine_run(__try_stop_module, &sref, NR_CPUS);
626 }
627
628 unsigned int module_refcount(struct module *mod)
629 {
630 unsigned int i, total = 0;
631
632 for (i = 0; i < NR_CPUS; i++)
633 total += local_read(&mod->ref[i].count);
634 return total;
635 }
636 EXPORT_SYMBOL(module_refcount);
637
638 /* This exists whether we can unload or not */
639 static void free_module(struct module *mod);
640
641 static void wait_for_zero_refcount(struct module *mod)
642 {
643 /* Since we might sleep for some time, drop the semaphore first */
644 mutex_unlock(&module_mutex);
645 for (;;) {
646 DEBUGP("Looking at refcount...\n");
647 set_current_state(TASK_UNINTERRUPTIBLE);
648 if (module_refcount(mod) == 0)
649 break;
650 schedule();
651 }
652 current->state = TASK_RUNNING;
653 mutex_lock(&module_mutex);
654 }
655
656 asmlinkage long
657 sys_delete_module(const char __user *name_user, unsigned int flags)
658 {
659 struct module *mod;
660 char name[MODULE_NAME_LEN];
661 int ret, forced = 0;
662
663 if (!capable(CAP_SYS_MODULE))
664 return -EPERM;
665
666 if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
667 return -EFAULT;
668 name[MODULE_NAME_LEN-1] = '\0';
669
670 if (mutex_lock_interruptible(&module_mutex) != 0)
671 return -EINTR;
672
673 mod = find_module(name);
674 if (!mod) {
675 ret = -ENOENT;
676 goto out;
677 }
678
679 if (!list_empty(&mod->modules_which_use_me)) {
680 /* Other modules depend on us: get rid of them first. */
681 ret = -EWOULDBLOCK;
682 goto out;
683 }
684
685 /* Doing init or already dying? */
686 if (mod->state != MODULE_STATE_LIVE) {
687 /* FIXME: if (force), slam module count and wake up
688 waiter --RR */
689 DEBUGP("%s already dying\n", mod->name);
690 ret = -EBUSY;
691 goto out;
692 }
693
694 /* If it has an init func, it must have an exit func to unload */
695 if ((mod->init != NULL && mod->exit == NULL)
696 || mod->unsafe) {
697 forced = try_force_unload(flags);
698 if (!forced) {
699 /* This module can't be removed */
700 ret = -EBUSY;
701 goto out;
702 }
703 }
704
705 /* Set this up before setting mod->state */
706 mod->waiter = current;
707
708 /* Stop the machine so refcounts can't move and disable module. */
709 ret = try_stop_module(mod, flags, &forced);
710 if (ret != 0)
711 goto out;
712
713 /* Never wait if forced. */
714 if (!forced && module_refcount(mod) != 0)
715 wait_for_zero_refcount(mod);
716
717 /* Final destruction now noone is using it. */
718 if (mod->exit != NULL) {
719 mutex_unlock(&module_mutex);
720 mod->exit();
721 mutex_lock(&module_mutex);
722 }
723 free_module(mod);
724
725 out:
726 mutex_unlock(&module_mutex);
727 return ret;
728 }
729
730 static void print_unload_info(struct seq_file *m, struct module *mod)
731 {
732 struct module_use *use;
733 int printed_something = 0;
734
735 seq_printf(m, " %u ", module_refcount(mod));
736
737 /* Always include a trailing , so userspace can differentiate
738 between this and the old multi-field proc format. */
739 list_for_each_entry(use, &mod->modules_which_use_me, list) {
740 printed_something = 1;
741 seq_printf(m, "%s,", use->module_which_uses->name);
742 }
743
744 if (mod->unsafe) {
745 printed_something = 1;
746 seq_printf(m, "[unsafe],");
747 }
748
749 if (mod->init != NULL && mod->exit == NULL) {
750 printed_something = 1;
751 seq_printf(m, "[permanent],");
752 }
753
754 if (!printed_something)
755 seq_printf(m, "-");
756 }
757
758 void __symbol_put(const char *symbol)
759 {
760 struct module *owner;
761 unsigned long flags;
762 const unsigned long *crc;
763
764 spin_lock_irqsave(&modlist_lock, flags);
765 if (!__find_symbol(symbol, &owner, &crc, 1))
766 BUG();
767 module_put(owner);
768 spin_unlock_irqrestore(&modlist_lock, flags);
769 }
770 EXPORT_SYMBOL(__symbol_put);
771
772 void symbol_put_addr(void *addr)
773 {
774 struct module *modaddr;
775
776 if (core_kernel_text((unsigned long)addr))
777 return;
778
779 if (!(modaddr = module_text_address((unsigned long)addr)))
780 BUG();
781 module_put(modaddr);
782 }
783 EXPORT_SYMBOL_GPL(symbol_put_addr);
784
785 static ssize_t show_refcnt(struct module_attribute *mattr,
786 struct module *mod, char *buffer)
787 {
788 /* sysfs holds a reference */
789 return sprintf(buffer, "%u\n", module_refcount(mod)-1);
790 }
791
792 static struct module_attribute refcnt = {
793 .attr = { .name = "refcnt", .mode = 0444, .owner = THIS_MODULE },
794 .show = show_refcnt,
795 };
796
797 void module_put(struct module *module)
798 {
799 if (module) {
800 unsigned int cpu = get_cpu();
801 local_dec(&module->ref[cpu].count);
802 /* Maybe they're waiting for us to drop reference? */
803 if (unlikely(!module_is_live(module)))
804 wake_up_process(module->waiter);
805 put_cpu();
806 }
807 }
808 EXPORT_SYMBOL(module_put);
809
810 #else /* !CONFIG_MODULE_UNLOAD */
811 static void print_unload_info(struct seq_file *m, struct module *mod)
812 {
813 /* We don't know the usage count, or what modules are using. */
814 seq_printf(m, " - -");
815 }
816
817 static inline void module_unload_free(struct module *mod)
818 {
819 }
820
821 static inline int use_module(struct module *a, struct module *b)
822 {
823 return strong_try_module_get(b);
824 }
825
826 static inline void module_unload_init(struct module *mod)
827 {
828 }
829 #endif /* CONFIG_MODULE_UNLOAD */
830
831 static ssize_t show_initstate(struct module_attribute *mattr,
832 struct module *mod, char *buffer)
833 {
834 const char *state = "unknown";
835
836 switch (mod->state) {
837 case MODULE_STATE_LIVE:
838 state = "live";
839 break;
840 case MODULE_STATE_COMING:
841 state = "coming";
842 break;
843 case MODULE_STATE_GOING:
844 state = "going";
845 break;
846 }
847 return sprintf(buffer, "%s\n", state);
848 }
849
850 static struct module_attribute initstate = {
851 .attr = { .name = "initstate", .mode = 0444, .owner = THIS_MODULE },
852 .show = show_initstate,
853 };
854
855 static struct module_attribute *modinfo_attrs[] = {
856 &modinfo_version,
857 &modinfo_srcversion,
858 &initstate,
859 #ifdef CONFIG_MODULE_UNLOAD
860 &refcnt,
861 #endif
862 NULL,
863 };
864
865 static const char vermagic[] = VERMAGIC_STRING;
866
867 #ifdef CONFIG_MODVERSIONS
868 static int check_version(Elf_Shdr *sechdrs,
869 unsigned int versindex,
870 const char *symname,
871 struct module *mod,
872 const unsigned long *crc)
873 {
874 unsigned int i, num_versions;
875 struct modversion_info *versions;
876
877 /* Exporting module didn't supply crcs? OK, we're already tainted. */
878 if (!crc)
879 return 1;
880
881 versions = (void *) sechdrs[versindex].sh_addr;
882 num_versions = sechdrs[versindex].sh_size
883 / sizeof(struct modversion_info);
884
885 for (i = 0; i < num_versions; i++) {
886 if (strcmp(versions[i].name, symname) != 0)
887 continue;
888
889 if (versions[i].crc == *crc)
890 return 1;
891 printk("%s: disagrees about version of symbol %s\n",
892 mod->name, symname);
893 DEBUGP("Found checksum %lX vs module %lX\n",
894 *crc, versions[i].crc);
895 return 0;
896 }
897 /* Not in module's version table. OK, but that taints the kernel. */
898 if (!(tainted & TAINT_FORCED_MODULE))
899 printk("%s: no version for \"%s\" found: kernel tainted.\n",
900 mod->name, symname);
901 add_taint_module(mod, TAINT_FORCED_MODULE);
902 return 1;
903 }
904
905 static inline int check_modstruct_version(Elf_Shdr *sechdrs,
906 unsigned int versindex,
907 struct module *mod)
908 {
909 const unsigned long *crc;
910 struct module *owner;
911
912 if (!__find_symbol("struct_module", &owner, &crc, 1))
913 BUG();
914 return check_version(sechdrs, versindex, "struct_module", mod,
915 crc);
916 }
917
918 /* First part is kernel version, which we ignore. */
919 static inline int same_magic(const char *amagic, const char *bmagic)
920 {
921 amagic += strcspn(amagic, " ");
922 bmagic += strcspn(bmagic, " ");
923 return strcmp(amagic, bmagic) == 0;
924 }
925 #else
926 static inline int check_version(Elf_Shdr *sechdrs,
927 unsigned int versindex,
928 const char *symname,
929 struct module *mod,
930 const unsigned long *crc)
931 {
932 return 1;
933 }
934
935 static inline int check_modstruct_version(Elf_Shdr *sechdrs,
936 unsigned int versindex,
937 struct module *mod)
938 {
939 return 1;
940 }
941
942 static inline int same_magic(const char *amagic, const char *bmagic)
943 {
944 return strcmp(amagic, bmagic) == 0;
945 }
946 #endif /* CONFIG_MODVERSIONS */
947
948 /* Resolve a symbol for this module. I.e. if we find one, record usage.
949 Must be holding module_mutex. */
950 static unsigned long resolve_symbol(Elf_Shdr *sechdrs,
951 unsigned int versindex,
952 const char *name,
953 struct module *mod)
954 {
955 struct module *owner;
956 unsigned long ret;
957 const unsigned long *crc;
958
959 ret = __find_symbol(name, &owner, &crc,
960 !(mod->taints & TAINT_PROPRIETARY_MODULE));
961 if (ret) {
962 /* use_module can fail due to OOM, or module unloading */
963 if (!check_version(sechdrs, versindex, name, mod, crc) ||
964 !use_module(mod, owner))
965 ret = 0;
966 }
967 return ret;
968 }
969
970
971 /*
972 * /sys/module/foo/sections stuff
973 * J. Corbet <corbet@lwn.net>
974 */
975 #ifdef CONFIG_KALLSYMS
976 static ssize_t module_sect_show(struct module_attribute *mattr,
977 struct module *mod, char *buf)
978 {
979 struct module_sect_attr *sattr =
980 container_of(mattr, struct module_sect_attr, mattr);
981 return sprintf(buf, "0x%lx\n", sattr->address);
982 }
983
984 static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
985 {
986 int section;
987
988 for (section = 0; section < sect_attrs->nsections; section++)
989 kfree(sect_attrs->attrs[section].name);
990 kfree(sect_attrs);
991 }
992
993 static void add_sect_attrs(struct module *mod, unsigned int nsect,
994 char *secstrings, Elf_Shdr *sechdrs)
995 {
996 unsigned int nloaded = 0, i, size[2];
997 struct module_sect_attrs *sect_attrs;
998 struct module_sect_attr *sattr;
999 struct attribute **gattr;
1000
1001 /* Count loaded sections and allocate structures */
1002 for (i = 0; i < nsect; i++)
1003 if (sechdrs[i].sh_flags & SHF_ALLOC)
1004 nloaded++;
1005 size[0] = ALIGN(sizeof(*sect_attrs)
1006 + nloaded * sizeof(sect_attrs->attrs[0]),
1007 sizeof(sect_attrs->grp.attrs[0]));
1008 size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]);
1009 sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
1010 if (sect_attrs == NULL)
1011 return;
1012
1013 /* Setup section attributes. */
1014 sect_attrs->grp.name = "sections";
1015 sect_attrs->grp.attrs = (void *)sect_attrs + size[0];
1016
1017 sect_attrs->nsections = 0;
1018 sattr = &sect_attrs->attrs[0];
1019 gattr = &sect_attrs->grp.attrs[0];
1020 for (i = 0; i < nsect; i++) {
1021 if (! (sechdrs[i].sh_flags & SHF_ALLOC))
1022 continue;
1023 sattr->address = sechdrs[i].sh_addr;
1024 sattr->name = kstrdup(secstrings + sechdrs[i].sh_name,
1025 GFP_KERNEL);
1026 if (sattr->name == NULL)
1027 goto out;
1028 sect_attrs->nsections++;
1029 sattr->mattr.show = module_sect_show;
1030 sattr->mattr.store = NULL;
1031 sattr->mattr.attr.name = sattr->name;
1032 sattr->mattr.attr.owner = mod;
1033 sattr->mattr.attr.mode = S_IRUGO;
1034 *(gattr++) = &(sattr++)->mattr.attr;
1035 }
1036 *gattr = NULL;
1037
1038 if (sysfs_create_group(&mod->mkobj.kobj, &sect_attrs->grp))
1039 goto out;
1040
1041 mod->sect_attrs = sect_attrs;
1042 return;
1043 out:
1044 free_sect_attrs(sect_attrs);
1045 }
1046
1047 static void remove_sect_attrs(struct module *mod)
1048 {
1049 if (mod->sect_attrs) {
1050 sysfs_remove_group(&mod->mkobj.kobj,
1051 &mod->sect_attrs->grp);
1052 /* We are positive that no one is using any sect attrs
1053 * at this point. Deallocate immediately. */
1054 free_sect_attrs(mod->sect_attrs);
1055 mod->sect_attrs = NULL;
1056 }
1057 }
1058
1059 #else
1060
1061 static inline void add_sect_attrs(struct module *mod, unsigned int nsect,
1062 char *sectstrings, Elf_Shdr *sechdrs)
1063 {
1064 }
1065
1066 static inline void remove_sect_attrs(struct module *mod)
1067 {
1068 }
1069 #endif /* CONFIG_KALLSYMS */
1070
1071 static int module_add_modinfo_attrs(struct module *mod)
1072 {
1073 struct module_attribute *attr;
1074 struct module_attribute *temp_attr;
1075 int error = 0;
1076 int i;
1077
1078 mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
1079 (ARRAY_SIZE(modinfo_attrs) + 1)),
1080 GFP_KERNEL);
1081 if (!mod->modinfo_attrs)
1082 return -ENOMEM;
1083
1084 temp_attr = mod->modinfo_attrs;
1085 for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
1086 if (!attr->test ||
1087 (attr->test && attr->test(mod))) {
1088 memcpy(temp_attr, attr, sizeof(*temp_attr));
1089 temp_attr->attr.owner = mod;
1090 error = sysfs_create_file(&mod->mkobj.kobj,&temp_attr->attr);
1091 ++temp_attr;
1092 }
1093 }
1094 return error;
1095 }
1096
1097 static void module_remove_modinfo_attrs(struct module *mod)
1098 {
1099 struct module_attribute *attr;
1100 int i;
1101
1102 for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
1103 /* pick a field to test for end of list */
1104 if (!attr->attr.name)
1105 break;
1106 sysfs_remove_file(&mod->mkobj.kobj,&attr->attr);
1107 if (attr->free)
1108 attr->free(mod);
1109 }
1110 kfree(mod->modinfo_attrs);
1111 }
1112
1113 static int mod_sysfs_init(struct module *mod)
1114 {
1115 int err;
1116
1117 if (!module_subsys.kset.subsys) {
1118 printk(KERN_ERR "%s: module_subsys not initialized\n",
1119 mod->name);
1120 err = -EINVAL;
1121 goto out;
1122 }
1123 memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
1124 err = kobject_set_name(&mod->mkobj.kobj, "%s", mod->name);
1125 if (err)
1126 goto out;
1127 kobj_set_kset_s(&mod->mkobj, module_subsys);
1128 mod->mkobj.mod = mod;
1129
1130 kobject_init(&mod->mkobj.kobj);
1131
1132 out:
1133 return err;
1134 }
1135
1136 static int mod_sysfs_setup(struct module *mod,
1137 struct kernel_param *kparam,
1138 unsigned int num_params)
1139 {
1140 int err;
1141
1142 /* delay uevent until full sysfs population */
1143 err = kobject_add(&mod->mkobj.kobj);
1144 if (err)
1145 goto out;
1146
1147 mod->holders_dir = kobject_add_dir(&mod->mkobj.kobj, "holders");
1148 if (!mod->holders_dir)
1149 goto out_unreg;
1150
1151 err = module_param_sysfs_setup(mod, kparam, num_params);
1152 if (err)
1153 goto out_unreg_holders;
1154
1155 err = module_add_modinfo_attrs(mod);
1156 if (err)
1157 goto out_unreg_param;
1158
1159 kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
1160 return 0;
1161
1162 out_unreg_param:
1163 module_param_sysfs_remove(mod);
1164 out_unreg_holders:
1165 kobject_unregister(mod->holders_dir);
1166 out_unreg:
1167 kobject_del(&mod->mkobj.kobj);
1168 kobject_put(&mod->mkobj.kobj);
1169 out:
1170 return err;
1171 }
1172
1173 static void mod_kobject_remove(struct module *mod)
1174 {
1175 module_remove_modinfo_attrs(mod);
1176 module_param_sysfs_remove(mod);
1177 if (mod->mkobj.drivers_dir)
1178 kobject_unregister(mod->mkobj.drivers_dir);
1179 if (mod->holders_dir)
1180 kobject_unregister(mod->holders_dir);
1181
1182 kobject_unregister(&mod->mkobj.kobj);
1183 }
1184
1185 /*
1186 * unlink the module with the whole machine is stopped with interrupts off
1187 * - this defends against kallsyms not taking locks
1188 */
1189 static int __unlink_module(void *_mod)
1190 {
1191 struct module *mod = _mod;
1192 list_del(&mod->list);
1193 return 0;
1194 }
1195
1196 /* Free a module, remove from lists, etc (must hold module mutex). */
1197 static void free_module(struct module *mod)
1198 {
1199 /* Delete from various lists */
1200 stop_machine_run(__unlink_module, mod, NR_CPUS);
1201 remove_sect_attrs(mod);
1202 mod_kobject_remove(mod);
1203
1204 unwind_remove_table(mod->unwind_info, 0);
1205
1206 /* Arch-specific cleanup. */
1207 module_arch_cleanup(mod);
1208
1209 /* Module unload stuff */
1210 module_unload_free(mod);
1211
1212 /* This may be NULL, but that's OK */
1213 module_free(mod, mod->module_init);
1214 kfree(mod->args);
1215 if (mod->percpu)
1216 percpu_modfree(mod->percpu);
1217
1218 /* Free lock-classes: */
1219 lockdep_free_key_range(mod->module_core, mod->core_size);
1220
1221 /* Finally, free the core (containing the module structure) */
1222 module_free(mod, mod->module_core);
1223 }
1224
1225 void *__symbol_get(const char *symbol)
1226 {
1227 struct module *owner;
1228 unsigned long value, flags;
1229 const unsigned long *crc;
1230
1231 spin_lock_irqsave(&modlist_lock, flags);
1232 value = __find_symbol(symbol, &owner, &crc, 1);
1233 if (value && !strong_try_module_get(owner))
1234 value = 0;
1235 spin_unlock_irqrestore(&modlist_lock, flags);
1236
1237 return (void *)value;
1238 }
1239 EXPORT_SYMBOL_GPL(__symbol_get);
1240
1241 /*
1242 * Ensure that an exported symbol [global namespace] does not already exist
1243 * in the Kernel or in some other modules exported symbol table.
1244 */
1245 static int verify_export_symbols(struct module *mod)
1246 {
1247 const char *name = NULL;
1248 unsigned long i, ret = 0;
1249 struct module *owner;
1250 const unsigned long *crc;
1251
1252 for (i = 0; i < mod->num_syms; i++)
1253 if (__find_symbol(mod->syms[i].name, &owner, &crc, 1)) {
1254 name = mod->syms[i].name;
1255 ret = -ENOEXEC;
1256 goto dup;
1257 }
1258
1259 for (i = 0; i < mod->num_gpl_syms; i++)
1260 if (__find_symbol(mod->gpl_syms[i].name, &owner, &crc, 1)) {
1261 name = mod->gpl_syms[i].name;
1262 ret = -ENOEXEC;
1263 goto dup;
1264 }
1265
1266 dup:
1267 if (ret)
1268 printk(KERN_ERR "%s: exports duplicate symbol %s (owned by %s)\n",
1269 mod->name, name, module_name(owner));
1270
1271 return ret;
1272 }
1273
1274 /* Change all symbols so that sh_value encodes the pointer directly. */
1275 static int simplify_symbols(Elf_Shdr *sechdrs,
1276 unsigned int symindex,
1277 const char *strtab,
1278 unsigned int versindex,
1279 unsigned int pcpuindex,
1280 struct module *mod)
1281 {
1282 Elf_Sym *sym = (void *)sechdrs[symindex].sh_addr;
1283 unsigned long secbase;
1284 unsigned int i, n = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
1285 int ret = 0;
1286
1287 for (i = 1; i < n; i++) {
1288 switch (sym[i].st_shndx) {
1289 case SHN_COMMON:
1290 /* We compiled with -fno-common. These are not
1291 supposed to happen. */
1292 DEBUGP("Common symbol: %s\n", strtab + sym[i].st_name);
1293 printk("%s: please compile with -fno-common\n",
1294 mod->name);
1295 ret = -ENOEXEC;
1296 break;
1297
1298 case SHN_ABS:
1299 /* Don't need to do anything */
1300 DEBUGP("Absolute symbol: 0x%08lx\n",
1301 (long)sym[i].st_value);
1302 break;
1303
1304 case SHN_UNDEF:
1305 sym[i].st_value
1306 = resolve_symbol(sechdrs, versindex,
1307 strtab + sym[i].st_name, mod);
1308
1309 /* Ok if resolved. */
1310 if (sym[i].st_value != 0)
1311 break;
1312 /* Ok if weak. */
1313 if (ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
1314 break;
1315
1316 printk(KERN_WARNING "%s: Unknown symbol %s\n",
1317 mod->name, strtab + sym[i].st_name);
1318 ret = -ENOENT;
1319 break;
1320
1321 default:
1322 /* Divert to percpu allocation if a percpu var. */
1323 if (sym[i].st_shndx == pcpuindex)
1324 secbase = (unsigned long)mod->percpu;
1325 else
1326 secbase = sechdrs[sym[i].st_shndx].sh_addr;
1327 sym[i].st_value += secbase;
1328 break;
1329 }
1330 }
1331
1332 return ret;
1333 }
1334
1335 /* Update size with this section: return offset. */
1336 static long get_offset(unsigned long *size, Elf_Shdr *sechdr)
1337 {
1338 long ret;
1339
1340 ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
1341 *size = ret + sechdr->sh_size;
1342 return ret;
1343 }
1344
1345 /* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
1346 might -- code, read-only data, read-write data, small data. Tally
1347 sizes, and place the offsets into sh_entsize fields: high bit means it
1348 belongs in init. */
1349 static void layout_sections(struct module *mod,
1350 const Elf_Ehdr *hdr,
1351 Elf_Shdr *sechdrs,
1352 const char *secstrings)
1353 {
1354 static unsigned long const masks[][2] = {
1355 /* NOTE: all executable code must be the first section
1356 * in this array; otherwise modify the text_size
1357 * finder in the two loops below */
1358 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
1359 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
1360 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
1361 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
1362 };
1363 unsigned int m, i;
1364
1365 for (i = 0; i < hdr->e_shnum; i++)
1366 sechdrs[i].sh_entsize = ~0UL;
1367
1368 DEBUGP("Core section allocation order:\n");
1369 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
1370 for (i = 0; i < hdr->e_shnum; ++i) {
1371 Elf_Shdr *s = &sechdrs[i];
1372
1373 if ((s->sh_flags & masks[m][0]) != masks[m][0]
1374 || (s->sh_flags & masks[m][1])
1375 || s->sh_entsize != ~0UL
1376 || strncmp(secstrings + s->sh_name,
1377 ".init", 5) == 0)
1378 continue;
1379 s->sh_entsize = get_offset(&mod->core_size, s);
1380 DEBUGP("\t%s\n", secstrings + s->sh_name);
1381 }
1382 if (m == 0)
1383 mod->core_text_size = mod->core_size;
1384 }
1385
1386 DEBUGP("Init section allocation order:\n");
1387 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
1388 for (i = 0; i < hdr->e_shnum; ++i) {
1389 Elf_Shdr *s = &sechdrs[i];
1390
1391 if ((s->sh_flags & masks[m][0]) != masks[m][0]
1392 || (s->sh_flags & masks[m][1])
1393 || s->sh_entsize != ~0UL
1394 || strncmp(secstrings + s->sh_name,
1395 ".init", 5) != 0)
1396 continue;
1397 s->sh_entsize = (get_offset(&mod->init_size, s)
1398 | INIT_OFFSET_MASK);
1399 DEBUGP("\t%s\n", secstrings + s->sh_name);
1400 }
1401 if (m == 0)
1402 mod->init_text_size = mod->init_size;
1403 }
1404 }
1405
1406 static void set_license(struct module *mod, const char *license)
1407 {
1408 if (!license)
1409 license = "unspecified";
1410
1411 if (!license_is_gpl_compatible(license)) {
1412 if (!(tainted & TAINT_PROPRIETARY_MODULE))
1413 printk(KERN_WARNING "%s: module license '%s' taints "
1414 "kernel.\n", mod->name, license);
1415 add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
1416 }
1417 }
1418
1419 /* Parse tag=value strings from .modinfo section */
1420 static char *next_string(char *string, unsigned long *secsize)
1421 {
1422 /* Skip non-zero chars */
1423 while (string[0]) {
1424 string++;
1425 if ((*secsize)-- <= 1)
1426 return NULL;
1427 }
1428
1429 /* Skip any zero padding. */
1430 while (!string[0]) {
1431 string++;
1432 if ((*secsize)-- <= 1)
1433 return NULL;
1434 }
1435 return string;
1436 }
1437
1438 static char *get_modinfo(Elf_Shdr *sechdrs,
1439 unsigned int info,
1440 const char *tag)
1441 {
1442 char *p;
1443 unsigned int taglen = strlen(tag);
1444 unsigned long size = sechdrs[info].sh_size;
1445
1446 for (p = (char *)sechdrs[info].sh_addr; p; p = next_string(p, &size)) {
1447 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
1448 return p + taglen + 1;
1449 }
1450 return NULL;
1451 }
1452
1453 static void setup_modinfo(struct module *mod, Elf_Shdr *sechdrs,
1454 unsigned int infoindex)
1455 {
1456 struct module_attribute *attr;
1457 int i;
1458
1459 for (i = 0; (attr = modinfo_attrs[i]); i++) {
1460 if (attr->setup)
1461 attr->setup(mod,
1462 get_modinfo(sechdrs,
1463 infoindex,
1464 attr->attr.name));
1465 }
1466 }
1467
1468 #ifdef CONFIG_KALLSYMS
1469 int is_exported(const char *name, const struct module *mod)
1470 {
1471 if (!mod && lookup_symbol(name, __start___ksymtab, __stop___ksymtab))
1472 return 1;
1473 else
1474 if (mod && lookup_symbol(name, mod->syms, mod->syms + mod->num_syms))
1475 return 1;
1476 else
1477 return 0;
1478 }
1479
1480 /* As per nm */
1481 static char elf_type(const Elf_Sym *sym,
1482 Elf_Shdr *sechdrs,
1483 const char *secstrings,
1484 struct module *mod)
1485 {
1486 if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
1487 if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
1488 return 'v';
1489 else
1490 return 'w';
1491 }
1492 if (sym->st_shndx == SHN_UNDEF)
1493 return 'U';
1494 if (sym->st_shndx == SHN_ABS)
1495 return 'a';
1496 if (sym->st_shndx >= SHN_LORESERVE)
1497 return '?';
1498 if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
1499 return 't';
1500 if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
1501 && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
1502 if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
1503 return 'r';
1504 else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
1505 return 'g';
1506 else
1507 return 'd';
1508 }
1509 if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
1510 if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
1511 return 's';
1512 else
1513 return 'b';
1514 }
1515 if (strncmp(secstrings + sechdrs[sym->st_shndx].sh_name,
1516 ".debug", strlen(".debug")) == 0)
1517 return 'n';
1518 return '?';
1519 }
1520
1521 static void add_kallsyms(struct module *mod,
1522 Elf_Shdr *sechdrs,
1523 unsigned int symindex,
1524 unsigned int strindex,
1525 const char *secstrings)
1526 {
1527 unsigned int i;
1528
1529 mod->symtab = (void *)sechdrs[symindex].sh_addr;
1530 mod->num_symtab = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
1531 mod->strtab = (void *)sechdrs[strindex].sh_addr;
1532
1533 /* Set types up while we still have access to sections. */
1534 for (i = 0; i < mod->num_symtab; i++)
1535 mod->symtab[i].st_info
1536 = elf_type(&mod->symtab[i], sechdrs, secstrings, mod);
1537 }
1538 #else
1539 static inline void add_kallsyms(struct module *mod,
1540 Elf_Shdr *sechdrs,
1541 unsigned int symindex,
1542 unsigned int strindex,
1543 const char *secstrings)
1544 {
1545 }
1546 #endif /* CONFIG_KALLSYMS */
1547
1548 /* Allocate and load the module: note that size of section 0 is always
1549 zero, and we rely on this for optional sections. */
1550 static struct module *load_module(void __user *umod,
1551 unsigned long len,
1552 const char __user *uargs)
1553 {
1554 Elf_Ehdr *hdr;
1555 Elf_Shdr *sechdrs;
1556 char *secstrings, *args, *modmagic, *strtab = NULL;
1557 unsigned int i;
1558 unsigned int symindex = 0;
1559 unsigned int strindex = 0;
1560 unsigned int setupindex;
1561 unsigned int exindex;
1562 unsigned int exportindex;
1563 unsigned int modindex;
1564 unsigned int obsparmindex;
1565 unsigned int infoindex;
1566 unsigned int gplindex;
1567 unsigned int crcindex;
1568 unsigned int gplcrcindex;
1569 unsigned int versindex;
1570 unsigned int pcpuindex;
1571 unsigned int gplfutureindex;
1572 unsigned int gplfuturecrcindex;
1573 unsigned int unwindex = 0;
1574 unsigned int unusedindex;
1575 unsigned int unusedcrcindex;
1576 unsigned int unusedgplindex;
1577 unsigned int unusedgplcrcindex;
1578 struct module *mod;
1579 long err = 0;
1580 void *percpu = NULL, *ptr = NULL; /* Stops spurious gcc warning */
1581 struct exception_table_entry *extable;
1582 mm_segment_t old_fs;
1583
1584 DEBUGP("load_module: umod=%p, len=%lu, uargs=%p\n",
1585 umod, len, uargs);
1586 if (len < sizeof(*hdr))
1587 return ERR_PTR(-ENOEXEC);
1588
1589 /* Suck in entire file: we'll want most of it. */
1590 /* vmalloc barfs on "unusual" numbers. Check here */
1591 if (len > 64 * 1024 * 1024 || (hdr = vmalloc(len)) == NULL)
1592 return ERR_PTR(-ENOMEM);
1593 if (copy_from_user(hdr, umod, len) != 0) {
1594 err = -EFAULT;
1595 goto free_hdr;
1596 }
1597
1598 /* Sanity checks against insmoding binaries or wrong arch,
1599 weird elf version */
1600 if (memcmp(hdr->e_ident, ELFMAG, 4) != 0
1601 || hdr->e_type != ET_REL
1602 || !elf_check_arch(hdr)
1603 || hdr->e_shentsize != sizeof(*sechdrs)) {
1604 err = -ENOEXEC;
1605 goto free_hdr;
1606 }
1607
1608 if (len < hdr->e_shoff + hdr->e_shnum * sizeof(Elf_Shdr))
1609 goto truncated;
1610
1611 /* Convenience variables */
1612 sechdrs = (void *)hdr + hdr->e_shoff;
1613 secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
1614 sechdrs[0].sh_addr = 0;
1615
1616 for (i = 1; i < hdr->e_shnum; i++) {
1617 if (sechdrs[i].sh_type != SHT_NOBITS
1618 && len < sechdrs[i].sh_offset + sechdrs[i].sh_size)
1619 goto truncated;
1620
1621 /* Mark all sections sh_addr with their address in the
1622 temporary image. */
1623 sechdrs[i].sh_addr = (size_t)hdr + sechdrs[i].sh_offset;
1624
1625 /* Internal symbols and strings. */
1626 if (sechdrs[i].sh_type == SHT_SYMTAB) {
1627 symindex = i;
1628 strindex = sechdrs[i].sh_link;
1629 strtab = (char *)hdr + sechdrs[strindex].sh_offset;
1630 }
1631 #ifndef CONFIG_MODULE_UNLOAD
1632 /* Don't load .exit sections */
1633 if (strncmp(secstrings+sechdrs[i].sh_name, ".exit", 5) == 0)
1634 sechdrs[i].sh_flags &= ~(unsigned long)SHF_ALLOC;
1635 #endif
1636 }
1637
1638 modindex = find_sec(hdr, sechdrs, secstrings,
1639 ".gnu.linkonce.this_module");
1640 if (!modindex) {
1641 printk(KERN_WARNING "No module found in object\n");
1642 err = -ENOEXEC;
1643 goto free_hdr;
1644 }
1645 mod = (void *)sechdrs[modindex].sh_addr;
1646
1647 if (symindex == 0) {
1648 printk(KERN_WARNING "%s: module has no symbols (stripped?)\n",
1649 mod->name);
1650 err = -ENOEXEC;
1651 goto free_hdr;
1652 }
1653
1654 /* Optional sections */
1655 exportindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab");
1656 gplindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_gpl");
1657 gplfutureindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_gpl_future");
1658 unusedindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_unused");
1659 unusedgplindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_unused_gpl");
1660 crcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab");
1661 gplcrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_gpl");
1662 gplfuturecrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_gpl_future");
1663 unusedcrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_unused");
1664 unusedgplcrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_unused_gpl");
1665 setupindex = find_sec(hdr, sechdrs, secstrings, "__param");
1666 exindex = find_sec(hdr, sechdrs, secstrings, "__ex_table");
1667 obsparmindex = find_sec(hdr, sechdrs, secstrings, "__obsparm");
1668 versindex = find_sec(hdr, sechdrs, secstrings, "__versions");
1669 infoindex = find_sec(hdr, sechdrs, secstrings, ".modinfo");
1670 pcpuindex = find_pcpusec(hdr, sechdrs, secstrings);
1671 #ifdef ARCH_UNWIND_SECTION_NAME
1672 unwindex = find_sec(hdr, sechdrs, secstrings, ARCH_UNWIND_SECTION_NAME);
1673 #endif
1674
1675 /* Don't keep modinfo section */
1676 sechdrs[infoindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
1677 #ifdef CONFIG_KALLSYMS
1678 /* Keep symbol and string tables for decoding later. */
1679 sechdrs[symindex].sh_flags |= SHF_ALLOC;
1680 sechdrs[strindex].sh_flags |= SHF_ALLOC;
1681 #endif
1682 if (unwindex)
1683 sechdrs[unwindex].sh_flags |= SHF_ALLOC;
1684
1685 /* Check module struct version now, before we try to use module. */
1686 if (!check_modstruct_version(sechdrs, versindex, mod)) {
1687 err = -ENOEXEC;
1688 goto free_hdr;
1689 }
1690
1691 modmagic = get_modinfo(sechdrs, infoindex, "vermagic");
1692 /* This is allowed: modprobe --force will invalidate it. */
1693 if (!modmagic) {
1694 add_taint_module(mod, TAINT_FORCED_MODULE);
1695 printk(KERN_WARNING "%s: no version magic, tainting kernel.\n",
1696 mod->name);
1697 } else if (!same_magic(modmagic, vermagic)) {
1698 printk(KERN_ERR "%s: version magic '%s' should be '%s'\n",
1699 mod->name, modmagic, vermagic);
1700 err = -ENOEXEC;
1701 goto free_hdr;
1702 }
1703
1704 /* Now copy in args */
1705 args = strndup_user(uargs, ~0UL >> 1);
1706 if (IS_ERR(args)) {
1707 err = PTR_ERR(args);
1708 goto free_hdr;
1709 }
1710
1711 if (find_module(mod->name)) {
1712 err = -EEXIST;
1713 goto free_mod;
1714 }
1715
1716 mod->state = MODULE_STATE_COMING;
1717
1718 /* Allow arches to frob section contents and sizes. */
1719 err = module_frob_arch_sections(hdr, sechdrs, secstrings, mod);
1720 if (err < 0)
1721 goto free_mod;
1722
1723 if (pcpuindex) {
1724 /* We have a special allocation for this section. */
1725 percpu = percpu_modalloc(sechdrs[pcpuindex].sh_size,
1726 sechdrs[pcpuindex].sh_addralign,
1727 mod->name);
1728 if (!percpu) {
1729 err = -ENOMEM;
1730 goto free_mod;
1731 }
1732 sechdrs[pcpuindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
1733 mod->percpu = percpu;
1734 }
1735
1736 /* Determine total sizes, and put offsets in sh_entsize. For now
1737 this is done generically; there doesn't appear to be any
1738 special cases for the architectures. */
1739 layout_sections(mod, hdr, sechdrs, secstrings);
1740
1741 /* Do the allocs. */
1742 ptr = module_alloc(mod->core_size);
1743 if (!ptr) {
1744 err = -ENOMEM;
1745 goto free_percpu;
1746 }
1747 memset(ptr, 0, mod->core_size);
1748 mod->module_core = ptr;
1749
1750 ptr = module_alloc(mod->init_size);
1751 if (!ptr && mod->init_size) {
1752 err = -ENOMEM;
1753 goto free_core;
1754 }
1755 memset(ptr, 0, mod->init_size);
1756 mod->module_init = ptr;
1757
1758 /* Transfer each section which specifies SHF_ALLOC */
1759 DEBUGP("final section addresses:\n");
1760 for (i = 0; i < hdr->e_shnum; i++) {
1761 void *dest;
1762
1763 if (!(sechdrs[i].sh_flags & SHF_ALLOC))
1764 continue;
1765
1766 if (sechdrs[i].sh_entsize & INIT_OFFSET_MASK)
1767 dest = mod->module_init
1768 + (sechdrs[i].sh_entsize & ~INIT_OFFSET_MASK);
1769 else
1770 dest = mod->module_core + sechdrs[i].sh_entsize;
1771
1772 if (sechdrs[i].sh_type != SHT_NOBITS)
1773 memcpy(dest, (void *)sechdrs[i].sh_addr,
1774 sechdrs[i].sh_size);
1775 /* Update sh_addr to point to copy in image. */
1776 sechdrs[i].sh_addr = (unsigned long)dest;
1777 DEBUGP("\t0x%lx %s\n", sechdrs[i].sh_addr, secstrings + sechdrs[i].sh_name);
1778 }
1779 /* Module has been moved. */
1780 mod = (void *)sechdrs[modindex].sh_addr;
1781
1782 /* Now we've moved module, initialize linked lists, etc. */
1783 module_unload_init(mod);
1784
1785 /* Initialize kobject, so we can reference it. */
1786 if (mod_sysfs_init(mod) != 0)
1787 goto cleanup;
1788
1789 /* Set up license info based on the info section */
1790 set_license(mod, get_modinfo(sechdrs, infoindex, "license"));
1791
1792 if (strcmp(mod->name, "ndiswrapper") == 0)
1793 add_taint(TAINT_PROPRIETARY_MODULE);
1794 if (strcmp(mod->name, "driverloader") == 0)
1795 add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
1796
1797 /* Set up MODINFO_ATTR fields */
1798 setup_modinfo(mod, sechdrs, infoindex);
1799
1800 /* Fix up syms, so that st_value is a pointer to location. */
1801 err = simplify_symbols(sechdrs, symindex, strtab, versindex, pcpuindex,
1802 mod);
1803 if (err < 0)
1804 goto cleanup;
1805
1806 /* Set up EXPORTed & EXPORT_GPLed symbols (section 0 is 0 length) */
1807 mod->num_syms = sechdrs[exportindex].sh_size / sizeof(*mod->syms);
1808 mod->syms = (void *)sechdrs[exportindex].sh_addr;
1809 if (crcindex)
1810 mod->crcs = (void *)sechdrs[crcindex].sh_addr;
1811 mod->num_gpl_syms = sechdrs[gplindex].sh_size / sizeof(*mod->gpl_syms);
1812 mod->gpl_syms = (void *)sechdrs[gplindex].sh_addr;
1813 if (gplcrcindex)
1814 mod->gpl_crcs = (void *)sechdrs[gplcrcindex].sh_addr;
1815 mod->num_gpl_future_syms = sechdrs[gplfutureindex].sh_size /
1816 sizeof(*mod->gpl_future_syms);
1817 mod->num_unused_syms = sechdrs[unusedindex].sh_size /
1818 sizeof(*mod->unused_syms);
1819 mod->num_unused_gpl_syms = sechdrs[unusedgplindex].sh_size /
1820 sizeof(*mod->unused_gpl_syms);
1821 mod->gpl_future_syms = (void *)sechdrs[gplfutureindex].sh_addr;
1822 if (gplfuturecrcindex)
1823 mod->gpl_future_crcs = (void *)sechdrs[gplfuturecrcindex].sh_addr;
1824
1825 mod->unused_syms = (void *)sechdrs[unusedindex].sh_addr;
1826 if (unusedcrcindex)
1827 mod->unused_crcs = (void *)sechdrs[unusedcrcindex].sh_addr;
1828 mod->unused_gpl_syms = (void *)sechdrs[unusedgplindex].sh_addr;
1829 if (unusedgplcrcindex)
1830 mod->unused_crcs = (void *)sechdrs[unusedgplcrcindex].sh_addr;
1831
1832 #ifdef CONFIG_MODVERSIONS
1833 if ((mod->num_syms && !crcindex) ||
1834 (mod->num_gpl_syms && !gplcrcindex) ||
1835 (mod->num_gpl_future_syms && !gplfuturecrcindex) ||
1836 (mod->num_unused_syms && !unusedcrcindex) ||
1837 (mod->num_unused_gpl_syms && !unusedgplcrcindex)) {
1838 printk(KERN_WARNING "%s: No versions for exported symbols."
1839 " Tainting kernel.\n", mod->name);
1840 add_taint_module(mod, TAINT_FORCED_MODULE);
1841 }
1842 #endif
1843
1844 /* Now do relocations. */
1845 for (i = 1; i < hdr->e_shnum; i++) {
1846 const char *strtab = (char *)sechdrs[strindex].sh_addr;
1847 unsigned int info = sechdrs[i].sh_info;
1848
1849 /* Not a valid relocation section? */
1850 if (info >= hdr->e_shnum)
1851 continue;
1852
1853 /* Don't bother with non-allocated sections */
1854 if (!(sechdrs[info].sh_flags & SHF_ALLOC))
1855 continue;
1856
1857 if (sechdrs[i].sh_type == SHT_REL)
1858 err = apply_relocate(sechdrs, strtab, symindex, i,mod);
1859 else if (sechdrs[i].sh_type == SHT_RELA)
1860 err = apply_relocate_add(sechdrs, strtab, symindex, i,
1861 mod);
1862 if (err < 0)
1863 goto cleanup;
1864 }
1865
1866 /* Find duplicate symbols */
1867 err = verify_export_symbols(mod);
1868
1869 if (err < 0)
1870 goto cleanup;
1871
1872 /* Set up and sort exception table */
1873 mod->num_exentries = sechdrs[exindex].sh_size / sizeof(*mod->extable);
1874 mod->extable = extable = (void *)sechdrs[exindex].sh_addr;
1875 sort_extable(extable, extable + mod->num_exentries);
1876
1877 /* Finally, copy percpu area over. */
1878 percpu_modcopy(mod->percpu, (void *)sechdrs[pcpuindex].sh_addr,
1879 sechdrs[pcpuindex].sh_size);
1880
1881 add_kallsyms(mod, sechdrs, symindex, strindex, secstrings);
1882
1883 err = module_finalize(hdr, sechdrs, mod);
1884 if (err < 0)
1885 goto cleanup;
1886
1887 /* flush the icache in correct context */
1888 old_fs = get_fs();
1889 set_fs(KERNEL_DS);
1890
1891 /*
1892 * Flush the instruction cache, since we've played with text.
1893 * Do it before processing of module parameters, so the module
1894 * can provide parameter accessor functions of its own.
1895 */
1896 if (mod->module_init)
1897 flush_icache_range((unsigned long)mod->module_init,
1898 (unsigned long)mod->module_init
1899 + mod->init_size);
1900 flush_icache_range((unsigned long)mod->module_core,
1901 (unsigned long)mod->module_core + mod->core_size);
1902
1903 set_fs(old_fs);
1904
1905 mod->args = args;
1906 if (obsparmindex)
1907 printk(KERN_WARNING "%s: Ignoring obsolete parameters\n",
1908 mod->name);
1909
1910 /* Size of section 0 is 0, so this works well if no params */
1911 err = parse_args(mod->name, mod->args,
1912 (struct kernel_param *)
1913 sechdrs[setupindex].sh_addr,
1914 sechdrs[setupindex].sh_size
1915 / sizeof(struct kernel_param),
1916 NULL);
1917 if (err < 0)
1918 goto arch_cleanup;
1919
1920 err = mod_sysfs_setup(mod,
1921 (struct kernel_param *)
1922 sechdrs[setupindex].sh_addr,
1923 sechdrs[setupindex].sh_size
1924 / sizeof(struct kernel_param));
1925 if (err < 0)
1926 goto arch_cleanup;
1927 add_sect_attrs(mod, hdr->e_shnum, secstrings, sechdrs);
1928
1929 /* Size of section 0 is 0, so this works well if no unwind info. */
1930 mod->unwind_info = unwind_add_table(mod,
1931 (void *)sechdrs[unwindex].sh_addr,
1932 sechdrs[unwindex].sh_size);
1933
1934 /* Get rid of temporary copy */
1935 vfree(hdr);
1936
1937 /* Done! */
1938 return mod;
1939
1940 arch_cleanup:
1941 module_arch_cleanup(mod);
1942 cleanup:
1943 module_unload_free(mod);
1944 module_free(mod, mod->module_init);
1945 free_core:
1946 module_free(mod, mod->module_core);
1947 free_percpu:
1948 if (percpu)
1949 percpu_modfree(percpu);
1950 free_mod:
1951 kfree(args);
1952 free_hdr:
1953 vfree(hdr);
1954 return ERR_PTR(err);
1955
1956 truncated:
1957 printk(KERN_ERR "Module len %lu truncated\n", len);
1958 err = -ENOEXEC;
1959 goto free_hdr;
1960 }
1961
1962 /*
1963 * link the module with the whole machine is stopped with interrupts off
1964 * - this defends against kallsyms not taking locks
1965 */
1966 static int __link_module(void *_mod)
1967 {
1968 struct module *mod = _mod;
1969 list_add(&mod->list, &modules);
1970 return 0;
1971 }
1972
1973 /* This is where the real work happens */
1974 asmlinkage long
1975 sys_init_module(void __user *umod,
1976 unsigned long len,
1977 const char __user *uargs)
1978 {
1979 struct module *mod;
1980 int ret = 0;
1981
1982 /* Must have permission */
1983 if (!capable(CAP_SYS_MODULE))
1984 return -EPERM;
1985
1986 /* Only one module load at a time, please */
1987 if (mutex_lock_interruptible(&module_mutex) != 0)
1988 return -EINTR;
1989
1990 /* Do all the hard work */
1991 mod = load_module(umod, len, uargs);
1992 if (IS_ERR(mod)) {
1993 mutex_unlock(&module_mutex);
1994 return PTR_ERR(mod);
1995 }
1996
1997 /* Now sew it into the lists. They won't access us, since
1998 strong_try_module_get() will fail. */
1999 stop_machine_run(__link_module, mod, NR_CPUS);
2000
2001 /* Drop lock so they can recurse */
2002 mutex_unlock(&module_mutex);
2003
2004 blocking_notifier_call_chain(&module_notify_list,
2005 MODULE_STATE_COMING, mod);
2006
2007 /* Start the module */
2008 if (mod->init != NULL)
2009 ret = mod->init();
2010 if (ret < 0) {
2011 /* Init routine failed: abort. Try to protect us from
2012 buggy refcounters. */
2013 mod->state = MODULE_STATE_GOING;
2014 synchronize_sched();
2015 if (mod->unsafe)
2016 printk(KERN_ERR "%s: module is now stuck!\n",
2017 mod->name);
2018 else {
2019 module_put(mod);
2020 mutex_lock(&module_mutex);
2021 free_module(mod);
2022 mutex_unlock(&module_mutex);
2023 }
2024 return ret;
2025 }
2026
2027 /* Now it's a first class citizen! */
2028 mutex_lock(&module_mutex);
2029 mod->state = MODULE_STATE_LIVE;
2030 /* Drop initial reference. */
2031 module_put(mod);
2032 unwind_remove_table(mod->unwind_info, 1);
2033 module_free(mod, mod->module_init);
2034 mod->module_init = NULL;
2035 mod->init_size = 0;
2036 mod->init_text_size = 0;
2037 mutex_unlock(&module_mutex);
2038
2039 return 0;
2040 }
2041
2042 static inline int within(unsigned long addr, void *start, unsigned long size)
2043 {
2044 return ((void *)addr >= start && (void *)addr < start + size);
2045 }
2046
2047 #ifdef CONFIG_KALLSYMS
2048 /*
2049 * This ignores the intensely annoying "mapping symbols" found
2050 * in ARM ELF files: $a, $t and $d.
2051 */
2052 static inline int is_arm_mapping_symbol(const char *str)
2053 {
2054 return str[0] == '$' && strchr("atd", str[1])
2055 && (str[2] == '\0' || str[2] == '.');
2056 }
2057
2058 static const char *get_ksymbol(struct module *mod,
2059 unsigned long addr,
2060 unsigned long *size,
2061 unsigned long *offset)
2062 {
2063 unsigned int i, best = 0;
2064 unsigned long nextval;
2065
2066 /* At worse, next value is at end of module */
2067 if (within(addr, mod->module_init, mod->init_size))
2068 nextval = (unsigned long)mod->module_init+mod->init_text_size;
2069 else
2070 nextval = (unsigned long)mod->module_core+mod->core_text_size;
2071
2072 /* Scan for closest preceeding symbol, and next symbol. (ELF
2073 starts real symbols at 1). */
2074 for (i = 1; i < mod->num_symtab; i++) {
2075 if (mod->symtab[i].st_shndx == SHN_UNDEF)
2076 continue;
2077
2078 /* We ignore unnamed symbols: they're uninformative
2079 * and inserted at a whim. */
2080 if (mod->symtab[i].st_value <= addr
2081 && mod->symtab[i].st_value > mod->symtab[best].st_value
2082 && *(mod->strtab + mod->symtab[i].st_name) != '\0'
2083 && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
2084 best = i;
2085 if (mod->symtab[i].st_value > addr
2086 && mod->symtab[i].st_value < nextval
2087 && *(mod->strtab + mod->symtab[i].st_name) != '\0'
2088 && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
2089 nextval = mod->symtab[i].st_value;
2090 }
2091
2092 if (!best)
2093 return NULL;
2094
2095 *size = nextval - mod->symtab[best].st_value;
2096 *offset = addr - mod->symtab[best].st_value;
2097 return mod->strtab + mod->symtab[best].st_name;
2098 }
2099
2100 /* For kallsyms to ask for address resolution. NULL means not found.
2101 We don't lock, as this is used for oops resolution and races are a
2102 lesser concern. */
2103 const char *module_address_lookup(unsigned long addr,
2104 unsigned long *size,
2105 unsigned long *offset,
2106 char **modname)
2107 {
2108 struct module *mod;
2109
2110 list_for_each_entry(mod, &modules, list) {
2111 if (within(addr, mod->module_init, mod->init_size)
2112 || within(addr, mod->module_core, mod->core_size)) {
2113 if (modname)
2114 *modname = mod->name;
2115 return get_ksymbol(mod, addr, size, offset);
2116 }
2117 }
2118 return NULL;
2119 }
2120
2121 struct module *module_get_kallsym(unsigned int symnum, unsigned long *value,
2122 char *type, char *name, size_t namelen)
2123 {
2124 struct module *mod;
2125
2126 mutex_lock(&module_mutex);
2127 list_for_each_entry(mod, &modules, list) {
2128 if (symnum < mod->num_symtab) {
2129 *value = mod->symtab[symnum].st_value;
2130 *type = mod->symtab[symnum].st_info;
2131 strlcpy(name, mod->strtab + mod->symtab[symnum].st_name,
2132 namelen);
2133 mutex_unlock(&module_mutex);
2134 return mod;
2135 }
2136 symnum -= mod->num_symtab;
2137 }
2138 mutex_unlock(&module_mutex);
2139 return NULL;
2140 }
2141
2142 static unsigned long mod_find_symname(struct module *mod, const char *name)
2143 {
2144 unsigned int i;
2145
2146 for (i = 0; i < mod->num_symtab; i++)
2147 if (strcmp(name, mod->strtab+mod->symtab[i].st_name) == 0 &&
2148 mod->symtab[i].st_info != 'U')
2149 return mod->symtab[i].st_value;
2150 return 0;
2151 }
2152
2153 /* Look for this name: can be of form module:name. */
2154 unsigned long module_kallsyms_lookup_name(const char *name)
2155 {
2156 struct module *mod;
2157 char *colon;
2158 unsigned long ret = 0;
2159
2160 /* Don't lock: we're in enough trouble already. */
2161 if ((colon = strchr(name, ':')) != NULL) {
2162 *colon = '\0';
2163 if ((mod = find_module(name)) != NULL)
2164 ret = mod_find_symname(mod, colon+1);
2165 *colon = ':';
2166 } else {
2167 list_for_each_entry(mod, &modules, list)
2168 if ((ret = mod_find_symname(mod, name)) != 0)
2169 break;
2170 }
2171 return ret;
2172 }
2173 #endif /* CONFIG_KALLSYMS */
2174
2175 /* Called by the /proc file system to return a list of modules. */
2176 static void *m_start(struct seq_file *m, loff_t *pos)
2177 {
2178 struct list_head *i;
2179 loff_t n = 0;
2180
2181 mutex_lock(&module_mutex);
2182 list_for_each(i, &modules) {
2183 if (n++ == *pos)
2184 break;
2185 }
2186 if (i == &modules)
2187 return NULL;
2188 return i;
2189 }
2190
2191 static void *m_next(struct seq_file *m, void *p, loff_t *pos)
2192 {
2193 struct list_head *i = p;
2194 (*pos)++;
2195 if (i->next == &modules)
2196 return NULL;
2197 return i->next;
2198 }
2199
2200 static void m_stop(struct seq_file *m, void *p)
2201 {
2202 mutex_unlock(&module_mutex);
2203 }
2204
2205 static char *taint_flags(unsigned int taints, char *buf)
2206 {
2207 int bx = 0;
2208
2209 if (taints) {
2210 buf[bx++] = '(';
2211 if (taints & TAINT_PROPRIETARY_MODULE)
2212 buf[bx++] = 'P';
2213 if (taints & TAINT_FORCED_MODULE)
2214 buf[bx++] = 'F';
2215 /*
2216 * TAINT_FORCED_RMMOD: could be added.
2217 * TAINT_UNSAFE_SMP, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't
2218 * apply to modules.
2219 */
2220 buf[bx++] = ')';
2221 }
2222 buf[bx] = '\0';
2223
2224 return buf;
2225 }
2226
2227 static int m_show(struct seq_file *m, void *p)
2228 {
2229 struct module *mod = list_entry(p, struct module, list);
2230 char buf[8];
2231
2232 seq_printf(m, "%s %lu",
2233 mod->name, mod->init_size + mod->core_size);
2234 print_unload_info(m, mod);
2235
2236 /* Informative for users. */
2237 seq_printf(m, " %s",
2238 mod->state == MODULE_STATE_GOING ? "Unloading":
2239 mod->state == MODULE_STATE_COMING ? "Loading":
2240 "Live");
2241 /* Used by oprofile and other similar tools. */
2242 seq_printf(m, " 0x%p", mod->module_core);
2243
2244 /* Taints info */
2245 if (mod->taints)
2246 seq_printf(m, " %s", taint_flags(mod->taints, buf));
2247
2248 seq_printf(m, "\n");
2249 return 0;
2250 }
2251
2252 /* Format: modulename size refcount deps address
2253
2254 Where refcount is a number or -, and deps is a comma-separated list
2255 of depends or -.
2256 */
2257 const struct seq_operations modules_op = {
2258 .start = m_start,
2259 .next = m_next,
2260 .stop = m_stop,
2261 .show = m_show
2262 };
2263
2264 /* Given an address, look for it in the module exception tables. */
2265 const struct exception_table_entry *search_module_extables(unsigned long addr)
2266 {
2267 unsigned long flags;
2268 const struct exception_table_entry *e = NULL;
2269 struct module *mod;
2270
2271 spin_lock_irqsave(&modlist_lock, flags);
2272 list_for_each_entry(mod, &modules, list) {
2273 if (mod->num_exentries == 0)
2274 continue;
2275
2276 e = search_extable(mod->extable,
2277 mod->extable + mod->num_exentries - 1,
2278 addr);
2279 if (e)
2280 break;
2281 }
2282 spin_unlock_irqrestore(&modlist_lock, flags);
2283
2284 /* Now, if we found one, we are running inside it now, hence
2285 we cannot unload the module, hence no refcnt needed. */
2286 return e;
2287 }
2288
2289 /*
2290 * Is this a valid module address?
2291 */
2292 int is_module_address(unsigned long addr)
2293 {
2294 unsigned long flags;
2295 struct module *mod;
2296
2297 spin_lock_irqsave(&modlist_lock, flags);
2298
2299 list_for_each_entry(mod, &modules, list) {
2300 if (within(addr, mod->module_core, mod->core_size)) {
2301 spin_unlock_irqrestore(&modlist_lock, flags);
2302 return 1;
2303 }
2304 }
2305
2306 spin_unlock_irqrestore(&modlist_lock, flags);
2307
2308 return 0;
2309 }
2310
2311
2312 /* Is this a valid kernel address? We don't grab the lock: we are oopsing. */
2313 struct module *__module_text_address(unsigned long addr)
2314 {
2315 struct module *mod;
2316
2317 list_for_each_entry(mod, &modules, list)
2318 if (within(addr, mod->module_init, mod->init_text_size)
2319 || within(addr, mod->module_core, mod->core_text_size))
2320 return mod;
2321 return NULL;
2322 }
2323
2324 struct module *module_text_address(unsigned long addr)
2325 {
2326 struct module *mod;
2327 unsigned long flags;
2328
2329 spin_lock_irqsave(&modlist_lock, flags);
2330 mod = __module_text_address(addr);
2331 spin_unlock_irqrestore(&modlist_lock, flags);
2332
2333 return mod;
2334 }
2335
2336 /* Don't grab lock, we're oopsing. */
2337 void print_modules(void)
2338 {
2339 struct module *mod;
2340 char buf[8];
2341
2342 printk("Modules linked in:");
2343 list_for_each_entry(mod, &modules, list)
2344 printk(" %s%s", mod->name, taint_flags(mod->taints, buf));
2345 printk("\n");
2346 }
2347
2348 static char *make_driver_name(struct device_driver *drv)
2349 {
2350 char *driver_name;
2351
2352 driver_name = kmalloc(strlen(drv->name) + strlen(drv->bus->name) + 2,
2353 GFP_KERNEL);
2354 if (!driver_name)
2355 return NULL;
2356
2357 sprintf(driver_name, "%s:%s", drv->bus->name, drv->name);
2358 return driver_name;
2359 }
2360
2361 static void module_create_drivers_dir(struct module_kobject *mk)
2362 {
2363 if (!mk || mk->drivers_dir)
2364 return;
2365
2366 mk->drivers_dir = kobject_add_dir(&mk->kobj, "drivers");
2367 }
2368
2369 void module_add_driver(struct module *mod, struct device_driver *drv)
2370 {
2371 char *driver_name;
2372 int no_warn;
2373 struct module_kobject *mk = NULL;
2374
2375 if (!drv)
2376 return;
2377
2378 if (mod)
2379 mk = &mod->mkobj;
2380 else if (drv->mod_name) {
2381 struct kobject *mkobj;
2382
2383 /* Lookup built-in module entry in /sys/modules */
2384 mkobj = kset_find_obj(&module_subsys.kset, drv->mod_name);
2385 if (mkobj)
2386 mk = container_of(mkobj, struct module_kobject, kobj);
2387 }
2388
2389 if (!mk)
2390 return;
2391
2392 /* Don't check return codes; these calls are idempotent */
2393 no_warn = sysfs_create_link(&drv->kobj, &mk->kobj, "module");
2394 driver_name = make_driver_name(drv);
2395 if (driver_name) {
2396 module_create_drivers_dir(mk);
2397 no_warn = sysfs_create_link(mk->drivers_dir, &drv->kobj,
2398 driver_name);
2399 kfree(driver_name);
2400 }
2401 }
2402 EXPORT_SYMBOL(module_add_driver);
2403
2404 void module_remove_driver(struct device_driver *drv)
2405 {
2406 char *driver_name;
2407
2408 if (!drv)
2409 return;
2410
2411 sysfs_remove_link(&drv->kobj, "module");
2412 if (drv->owner && drv->owner->mkobj.drivers_dir) {
2413 driver_name = make_driver_name(drv);
2414 if (driver_name) {
2415 sysfs_remove_link(drv->owner->mkobj.drivers_dir,
2416 driver_name);
2417 kfree(driver_name);
2418 }
2419 }
2420 }
2421 EXPORT_SYMBOL(module_remove_driver);
2422
2423 #ifdef CONFIG_MODVERSIONS
2424 /* Generate the signature for struct module here, too, for modversions. */
2425 void struct_module(struct module *mod) { return; }
2426 EXPORT_SYMBOL(struct_module);
2427 #endif
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree