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Make forced module loading optional
[linux/fpc-iii.git] / kernel / module.c
blob8e4528c9909feab87fe000ea56beb3d69fc26819
1 /*
2 Copyright (C) 2002 Richard Henderson
3 Copyright (C) 2001 Rusty Russell, 2002 Rusty Russell IBM.
4
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 2 of the License, or
8 (at your option) any later version.
9
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
14
15 You should have received a copy of the GNU General Public License
16 along with this program; if not, write to the Free Software
17 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 */
19 #include <linux/module.h>
20 #include <linux/moduleloader.h>
21 #include <linux/init.h>
22 #include <linux/kallsyms.h>
23 #include <linux/sysfs.h>
24 #include <linux/kernel.h>
25 #include <linux/slab.h>
26 #include <linux/vmalloc.h>
27 #include <linux/elf.h>
28 #include <linux/seq_file.h>
29 #include <linux/syscalls.h>
30 #include <linux/fcntl.h>
31 #include <linux/rcupdate.h>
32 #include <linux/capability.h>
33 #include <linux/cpu.h>
34 #include <linux/moduleparam.h>
35 #include <linux/errno.h>
36 #include <linux/err.h>
37 #include <linux/vermagic.h>
38 #include <linux/notifier.h>
39 #include <linux/sched.h>
40 #include <linux/stop_machine.h>
41 #include <linux/device.h>
42 #include <linux/string.h>
43 #include <linux/mutex.h>
44 #include <linux/unwind.h>
45 #include <asm/uaccess.h>
46 #include <asm/cacheflush.h>
47 #include <linux/license.h>
48 #include <asm/sections.h>
49
50 #if 0
51 #define DEBUGP printk
52 #else
53 #define DEBUGP(fmt , a...)
54 #endif
55
56 #ifndef ARCH_SHF_SMALL
57 #define ARCH_SHF_SMALL 0
58 #endif
59
60 /* If this is set, the section belongs in the init part of the module */
61 #define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
62
63 /* List of modules, protected by module_mutex or preempt_disable
64 * (add/delete uses stop_machine). */
65 static DEFINE_MUTEX(module_mutex);
66 static LIST_HEAD(modules);
67
68 /* Waiting for a module to finish initializing? */
69 static DECLARE_WAIT_QUEUE_HEAD(module_wq);
70
71 static BLOCKING_NOTIFIER_HEAD(module_notify_list);
72
73 int register_module_notifier(struct notifier_block * nb)
74 {
75 return blocking_notifier_chain_register(&module_notify_list, nb);
76 }
77 EXPORT_SYMBOL(register_module_notifier);
78
79 int unregister_module_notifier(struct notifier_block * nb)
80 {
81 return blocking_notifier_chain_unregister(&module_notify_list, nb);
82 }
83 EXPORT_SYMBOL(unregister_module_notifier);
84
85 /* We require a truly strong try_module_get(): 0 means failure due to
86 ongoing or failed initialization etc. */
87 static inline int strong_try_module_get(struct module *mod)
88 {
89 if (mod && mod->state == MODULE_STATE_COMING)
90 return -EBUSY;
91 if (try_module_get(mod))
92 return 0;
93 else
94 return -ENOENT;
95 }
96
97 static inline void add_taint_module(struct module *mod, unsigned flag)
98 {
99 add_taint(flag);
100 mod->taints |= flag;
101 }
102
103 /*
104 * A thread that wants to hold a reference to a module only while it
105 * is running can call this to safely exit. nfsd and lockd use this.
106 */
107 void __module_put_and_exit(struct module *mod, long code)
108 {
109 module_put(mod);
110 do_exit(code);
111 }
112 EXPORT_SYMBOL(__module_put_and_exit);
113
114 /* Find a module section: 0 means not found. */
115 static unsigned int find_sec(Elf_Ehdr *hdr,
116 Elf_Shdr *sechdrs,
117 const char *secstrings,
118 const char *name)
119 {
120 unsigned int i;
121
122 for (i = 1; i < hdr->e_shnum; i++)
123 /* Alloc bit cleared means "ignore it." */
124 if ((sechdrs[i].sh_flags & SHF_ALLOC)
125 && strcmp(secstrings+sechdrs[i].sh_name, name) == 0)
126 return i;
127 return 0;
128 }
129
130 /* Provided by the linker */
131 extern const struct kernel_symbol __start___ksymtab[];
132 extern const struct kernel_symbol __stop___ksymtab[];
133 extern const struct kernel_symbol __start___ksymtab_gpl[];
134 extern const struct kernel_symbol __stop___ksymtab_gpl[];
135 extern const struct kernel_symbol __start___ksymtab_gpl_future[];
136 extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
137 extern const struct kernel_symbol __start___ksymtab_unused[];
138 extern const struct kernel_symbol __stop___ksymtab_unused[];
139 extern const struct kernel_symbol __start___ksymtab_unused_gpl[];
140 extern const struct kernel_symbol __stop___ksymtab_unused_gpl[];
141 extern const struct kernel_symbol __start___ksymtab_gpl_future[];
142 extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
143 extern const unsigned long __start___kcrctab[];
144 extern const unsigned long __start___kcrctab_gpl[];
145 extern const unsigned long __start___kcrctab_gpl_future[];
146 extern const unsigned long __start___kcrctab_unused[];
147 extern const unsigned long __start___kcrctab_unused_gpl[];
148
149 #ifndef CONFIG_MODVERSIONS
150 #define symversion(base, idx) NULL
151 #else
152 #define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
153 #endif
154
155 /* lookup symbol in given range of kernel_symbols */
156 static const struct kernel_symbol *lookup_symbol(const char *name,
157 const struct kernel_symbol *start,
158 const struct kernel_symbol *stop)
159 {
160 const struct kernel_symbol *ks = start;
161 for (; ks < stop; ks++)
162 if (strcmp(ks->name, name) == 0)
163 return ks;
164 return NULL;
165 }
166
167 static bool always_ok(bool gplok, bool warn, const char *name)
168 {
169 return true;
170 }
171
172 static bool printk_unused_warning(bool gplok, bool warn, const char *name)
173 {
174 if (warn) {
175 printk(KERN_WARNING "Symbol %s is marked as UNUSED, "
176 "however this module is using it.\n", name);
177 printk(KERN_WARNING
178 "This symbol will go away in the future.\n");
179 printk(KERN_WARNING
180 "Please evalute if this is the right api to use and if "
181 "it really is, submit a report the linux kernel "
182 "mailinglist together with submitting your code for "
183 "inclusion.\n");
184 }
185 return true;
186 }
187
188 static bool gpl_only_unused_warning(bool gplok, bool warn, const char *name)
189 {
190 if (!gplok)
191 return false;
192 return printk_unused_warning(gplok, warn, name);
193 }
194
195 static bool gpl_only(bool gplok, bool warn, const char *name)
196 {
197 return gplok;
198 }
199
200 static bool warn_if_not_gpl(bool gplok, bool warn, const char *name)
201 {
202 if (!gplok && warn) {
203 printk(KERN_WARNING "Symbol %s is being used "
204 "by a non-GPL module, which will not "
205 "be allowed in the future\n", name);
206 printk(KERN_WARNING "Please see the file "
207 "Documentation/feature-removal-schedule.txt "
208 "in the kernel source tree for more details.\n");
209 }
210 return true;
211 }
212
213 struct symsearch {
214 const struct kernel_symbol *start, *stop;
215 const unsigned long *crcs;
216 bool (*check)(bool gplok, bool warn, const char *name);
217 };
218
219 /* Look through this array of symbol tables for a symbol match which
220 * passes the check function. */
221 static const struct kernel_symbol *search_symarrays(const struct symsearch *arr,
222 unsigned int num,
223 const char *name,
224 bool gplok,
225 bool warn,
226 const unsigned long **crc)
227 {
228 unsigned int i;
229 const struct kernel_symbol *ks;
230
231 for (i = 0; i < num; i++) {
232 ks = lookup_symbol(name, arr[i].start, arr[i].stop);
233 if (!ks || !arr[i].check(gplok, warn, name))
234 continue;
235
236 if (crc)
237 *crc = symversion(arr[i].crcs, ks - arr[i].start);
238 return ks;
239 }
240 return NULL;
241 }
242
243 /* Find a symbol, return value, (optional) crc and (optional) module
244 * which owns it */
245 static unsigned long find_symbol(const char *name,
246 struct module **owner,
247 const unsigned long **crc,
248 bool gplok,
249 bool warn)
250 {
251 struct module *mod;
252 const struct kernel_symbol *ks;
253 const struct symsearch arr[] = {
254 { __start___ksymtab, __stop___ksymtab, __start___kcrctab,
255 always_ok },
256 { __start___ksymtab_gpl, __stop___ksymtab_gpl,
257 __start___kcrctab_gpl, gpl_only },
258 { __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future,
259 __start___kcrctab_gpl_future, warn_if_not_gpl },
260 { __start___ksymtab_unused, __stop___ksymtab_unused,
261 __start___kcrctab_unused, printk_unused_warning },
262 { __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl,
263 __start___kcrctab_unused_gpl, gpl_only_unused_warning },
264 };
265
266 /* Core kernel first. */
267 ks = search_symarrays(arr, ARRAY_SIZE(arr), name, gplok, warn, crc);
268 if (ks) {
269 if (owner)
270 *owner = NULL;
271 return ks->value;
272 }
273
274 /* Now try modules. */
275 list_for_each_entry(mod, &modules, list) {
276 struct symsearch arr[] = {
277 { mod->syms, mod->syms + mod->num_syms, mod->crcs,
278 always_ok },
279 { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
280 mod->gpl_crcs, gpl_only },
281 { mod->gpl_future_syms,
282 mod->gpl_future_syms + mod->num_gpl_future_syms,
283 mod->gpl_future_crcs, warn_if_not_gpl },
284 { mod->unused_syms,
285 mod->unused_syms + mod->num_unused_syms,
286 mod->unused_crcs, printk_unused_warning },
287 { mod->unused_gpl_syms,
288 mod->unused_gpl_syms + mod->num_unused_gpl_syms,
289 mod->unused_gpl_crcs, gpl_only_unused_warning },
290 };
291
292 ks = search_symarrays(arr, ARRAY_SIZE(arr),
293 name, gplok, warn, crc);
294 if (ks) {
295 if (owner)
296 *owner = mod;
297 return ks->value;
298 }
299 }
300
301 DEBUGP("Failed to find symbol %s\n", name);
302 return -ENOENT;
303 }
304
305 /* Search for module by name: must hold module_mutex. */
306 static struct module *find_module(const char *name)
307 {
308 struct module *mod;
309
310 list_for_each_entry(mod, &modules, list) {
311 if (strcmp(mod->name, name) == 0)
312 return mod;
313 }
314 return NULL;
315 }
316
317 #ifdef CONFIG_SMP
318 /* Number of blocks used and allocated. */
319 static unsigned int pcpu_num_used, pcpu_num_allocated;
320 /* Size of each block. -ve means used. */
321 static int *pcpu_size;
322
323 static int split_block(unsigned int i, unsigned short size)
324 {
325 /* Reallocation required? */
326 if (pcpu_num_used + 1 > pcpu_num_allocated) {
327 int *new;
328
329 new = krealloc(pcpu_size, sizeof(new[0])*pcpu_num_allocated*2,
330 GFP_KERNEL);
331 if (!new)
332 return 0;
333
334 pcpu_num_allocated *= 2;
335 pcpu_size = new;
336 }
337
338 /* Insert a new subblock */
339 memmove(&pcpu_size[i+1], &pcpu_size[i],
340 sizeof(pcpu_size[0]) * (pcpu_num_used - i));
341 pcpu_num_used++;
342
343 pcpu_size[i+1] -= size;
344 pcpu_size[i] = size;
345 return 1;
346 }
347
348 static inline unsigned int block_size(int val)
349 {
350 if (val < 0)
351 return -val;
352 return val;
353 }
354
355 static void *percpu_modalloc(unsigned long size, unsigned long align,
356 const char *name)
357 {
358 unsigned long extra;
359 unsigned int i;
360 void *ptr;
361
362 if (align > PAGE_SIZE) {
363 printk(KERN_WARNING "%s: per-cpu alignment %li > %li\n",
364 name, align, PAGE_SIZE);
365 align = PAGE_SIZE;
366 }
367
368 ptr = __per_cpu_start;
369 for (i = 0; i < pcpu_num_used; ptr += block_size(pcpu_size[i]), i++) {
370 /* Extra for alignment requirement. */
371 extra = ALIGN((unsigned long)ptr, align) - (unsigned long)ptr;
372 BUG_ON(i == 0 && extra != 0);
373
374 if (pcpu_size[i] < 0 || pcpu_size[i] < extra + size)
375 continue;
376
377 /* Transfer extra to previous block. */
378 if (pcpu_size[i-1] < 0)
379 pcpu_size[i-1] -= extra;
380 else
381 pcpu_size[i-1] += extra;
382 pcpu_size[i] -= extra;
383 ptr += extra;
384
385 /* Split block if warranted */
386 if (pcpu_size[i] - size > sizeof(unsigned long))
387 if (!split_block(i, size))
388 return NULL;
389
390 /* Mark allocated */
391 pcpu_size[i] = -pcpu_size[i];
392 return ptr;
393 }
394
395 printk(KERN_WARNING "Could not allocate %lu bytes percpu data\n",
396 size);
397 return NULL;
398 }
399
400 static void percpu_modfree(void *freeme)
401 {
402 unsigned int i;
403 void *ptr = __per_cpu_start + block_size(pcpu_size[0]);
404
405 /* First entry is core kernel percpu data. */
406 for (i = 1; i < pcpu_num_used; ptr += block_size(pcpu_size[i]), i++) {
407 if (ptr == freeme) {
408 pcpu_size[i] = -pcpu_size[i];
409 goto free;
410 }
411 }
412 BUG();
413
414 free:
415 /* Merge with previous? */
416 if (pcpu_size[i-1] >= 0) {
417 pcpu_size[i-1] += pcpu_size[i];
418 pcpu_num_used--;
419 memmove(&pcpu_size[i], &pcpu_size[i+1],
420 (pcpu_num_used - i) * sizeof(pcpu_size[0]));
421 i--;
422 }
423 /* Merge with next? */
424 if (i+1 < pcpu_num_used && pcpu_size[i+1] >= 0) {
425 pcpu_size[i] += pcpu_size[i+1];
426 pcpu_num_used--;
427 memmove(&pcpu_size[i+1], &pcpu_size[i+2],
428 (pcpu_num_used - (i+1)) * sizeof(pcpu_size[0]));
429 }
430 }
431
432 static unsigned int find_pcpusec(Elf_Ehdr *hdr,
433 Elf_Shdr *sechdrs,
434 const char *secstrings)
435 {
436 return find_sec(hdr, sechdrs, secstrings, ".data.percpu");
437 }
438
439 static void percpu_modcopy(void *pcpudest, const void *from, unsigned long size)
440 {
441 int cpu;
442
443 for_each_possible_cpu(cpu)
444 memcpy(pcpudest + per_cpu_offset(cpu), from, size);
445 }
446
447 static int percpu_modinit(void)
448 {
449 pcpu_num_used = 2;
450 pcpu_num_allocated = 2;
451 pcpu_size = kmalloc(sizeof(pcpu_size[0]) * pcpu_num_allocated,
452 GFP_KERNEL);
453 /* Static in-kernel percpu data (used). */
454 pcpu_size[0] = -(__per_cpu_end-__per_cpu_start);
455 /* Free room. */
456 pcpu_size[1] = PERCPU_ENOUGH_ROOM + pcpu_size[0];
457 if (pcpu_size[1] < 0) {
458 printk(KERN_ERR "No per-cpu room for modules.\n");
459 pcpu_num_used = 1;
460 }
461
462 return 0;
463 }
464 __initcall(percpu_modinit);
465 #else /* ... !CONFIG_SMP */
466 static inline void *percpu_modalloc(unsigned long size, unsigned long align,
467 const char *name)
468 {
469 return NULL;
470 }
471 static inline void percpu_modfree(void *pcpuptr)
472 {
473 BUG();
474 }
475 static inline unsigned int find_pcpusec(Elf_Ehdr *hdr,
476 Elf_Shdr *sechdrs,
477 const char *secstrings)
478 {
479 return 0;
480 }
481 static inline void percpu_modcopy(void *pcpudst, const void *src,
482 unsigned long size)
483 {
484 /* pcpusec should be 0, and size of that section should be 0. */
485 BUG_ON(size != 0);
486 }
487 #endif /* CONFIG_SMP */
488
489 #define MODINFO_ATTR(field) \
490 static void setup_modinfo_##field(struct module *mod, const char *s) \
491 { \
492 mod->field = kstrdup(s, GFP_KERNEL); \
493 } \
494 static ssize_t show_modinfo_##field(struct module_attribute *mattr, \
495 struct module *mod, char *buffer) \
496 { \
497 return sprintf(buffer, "%s\n", mod->field); \
498 } \
499 static int modinfo_##field##_exists(struct module *mod) \
500 { \
501 return mod->field != NULL; \
502 } \
503 static void free_modinfo_##field(struct module *mod) \
504 { \
505 kfree(mod->field); \
506 mod->field = NULL; \
507 } \
508 static struct module_attribute modinfo_##field = { \
509 .attr = { .name = __stringify(field), .mode = 0444 }, \
510 .show = show_modinfo_##field, \
511 .setup = setup_modinfo_##field, \
512 .test = modinfo_##field##_exists, \
513 .free = free_modinfo_##field, \
514 };
515
516 MODINFO_ATTR(version);
517 MODINFO_ATTR(srcversion);
518
519 static char last_unloaded_module[MODULE_NAME_LEN+1];
520
521 #ifdef CONFIG_MODULE_UNLOAD
522 /* Init the unload section of the module. */
523 static void module_unload_init(struct module *mod)
524 {
525 unsigned int i;
526
527 INIT_LIST_HEAD(&mod->modules_which_use_me);
528 for (i = 0; i < NR_CPUS; i++)
529 local_set(&mod->ref[i].count, 0);
530 /* Hold reference count during initialization. */
531 local_set(&mod->ref[raw_smp_processor_id()].count, 1);
532 /* Backwards compatibility macros put refcount during init. */
533 mod->waiter = current;
534 }
535
536 /* modules using other modules */
537 struct module_use
538 {
539 struct list_head list;
540 struct module *module_which_uses;
541 };
542
543 /* Does a already use b? */
544 static int already_uses(struct module *a, struct module *b)
545 {
546 struct module_use *use;
547
548 list_for_each_entry(use, &b->modules_which_use_me, list) {
549 if (use->module_which_uses == a) {
550 DEBUGP("%s uses %s!\n", a->name, b->name);
551 return 1;
552 }
553 }
554 DEBUGP("%s does not use %s!\n", a->name, b->name);
555 return 0;
556 }
557
558 /* Module a uses b */
559 static int use_module(struct module *a, struct module *b)
560 {
561 struct module_use *use;
562 int no_warn, err;
563
564 if (b == NULL || already_uses(a, b)) return 1;
565
566 /* If we're interrupted or time out, we fail. */
567 if (wait_event_interruptible_timeout(
568 module_wq, (err = strong_try_module_get(b)) != -EBUSY,
569 30 * HZ) <= 0) {
570 printk("%s: gave up waiting for init of module %s.\n",
571 a->name, b->name);
572 return 0;
573 }
574
575 /* If strong_try_module_get() returned a different error, we fail. */
576 if (err)
577 return 0;
578
579 DEBUGP("Allocating new usage for %s.\n", a->name);
580 use = kmalloc(sizeof(*use), GFP_ATOMIC);
581 if (!use) {
582 printk("%s: out of memory loading\n", a->name);
583 module_put(b);
584 return 0;
585 }
586
587 use->module_which_uses = a;
588 list_add(&use->list, &b->modules_which_use_me);
589 no_warn = sysfs_create_link(b->holders_dir, &a->mkobj.kobj, a->name);
590 return 1;
591 }
592
593 /* Clear the unload stuff of the module. */
594 static void module_unload_free(struct module *mod)
595 {
596 struct module *i;
597
598 list_for_each_entry(i, &modules, list) {
599 struct module_use *use;
600
601 list_for_each_entry(use, &i->modules_which_use_me, list) {
602 if (use->module_which_uses == mod) {
603 DEBUGP("%s unusing %s\n", mod->name, i->name);
604 module_put(i);
605 list_del(&use->list);
606 kfree(use);
607 sysfs_remove_link(i->holders_dir, mod->name);
608 /* There can be at most one match. */
609 break;
610 }
611 }
612 }
613 }
614
615 #ifdef CONFIG_MODULE_FORCE_UNLOAD
616 static inline int try_force_unload(unsigned int flags)
617 {
618 int ret = (flags & O_TRUNC);
619 if (ret)
620 add_taint(TAINT_FORCED_RMMOD);
621 return ret;
622 }
623 #else
624 static inline int try_force_unload(unsigned int flags)
625 {
626 return 0;
627 }
628 #endif /* CONFIG_MODULE_FORCE_UNLOAD */
629
630 struct stopref
631 {
632 struct module *mod;
633 int flags;
634 int *forced;
635 };
636
637 /* Whole machine is stopped with interrupts off when this runs. */
638 static int __try_stop_module(void *_sref)
639 {
640 struct stopref *sref = _sref;
641
642 /* If it's not unused, quit unless we are told to block. */
643 if ((sref->flags & O_NONBLOCK) && module_refcount(sref->mod) != 0) {
644 if (!(*sref->forced = try_force_unload(sref->flags)))
645 return -EWOULDBLOCK;
646 }
647
648 /* Mark it as dying. */
649 sref->mod->state = MODULE_STATE_GOING;
650 return 0;
651 }
652
653 static int try_stop_module(struct module *mod, int flags, int *forced)
654 {
655 struct stopref sref = { mod, flags, forced };
656
657 return stop_machine_run(__try_stop_module, &sref, NR_CPUS);
658 }
659
660 unsigned int module_refcount(struct module *mod)
661 {
662 unsigned int i, total = 0;
663
664 for (i = 0; i < NR_CPUS; i++)
665 total += local_read(&mod->ref[i].count);
666 return total;
667 }
668 EXPORT_SYMBOL(module_refcount);
669
670 /* This exists whether we can unload or not */
671 static void free_module(struct module *mod);
672
673 static void wait_for_zero_refcount(struct module *mod)
674 {
675 /* Since we might sleep for some time, release the mutex first */
676 mutex_unlock(&module_mutex);
677 for (;;) {
678 DEBUGP("Looking at refcount...\n");
679 set_current_state(TASK_UNINTERRUPTIBLE);
680 if (module_refcount(mod) == 0)
681 break;
682 schedule();
683 }
684 current->state = TASK_RUNNING;
685 mutex_lock(&module_mutex);
686 }
687
688 asmlinkage long
689 sys_delete_module(const char __user *name_user, unsigned int flags)
690 {
691 struct module *mod;
692 char name[MODULE_NAME_LEN];
693 int ret, forced = 0;
694
695 if (!capable(CAP_SYS_MODULE))
696 return -EPERM;
697
698 if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
699 return -EFAULT;
700 name[MODULE_NAME_LEN-1] = '\0';
701
702 if (mutex_lock_interruptible(&module_mutex) != 0)
703 return -EINTR;
704
705 mod = find_module(name);
706 if (!mod) {
707 ret = -ENOENT;
708 goto out;
709 }
710
711 if (!list_empty(&mod->modules_which_use_me)) {
712 /* Other modules depend on us: get rid of them first. */
713 ret = -EWOULDBLOCK;
714 goto out;
715 }
716
717 /* Doing init or already dying? */
718 if (mod->state != MODULE_STATE_LIVE) {
719 /* FIXME: if (force), slam module count and wake up
720 waiter --RR */
721 DEBUGP("%s already dying\n", mod->name);
722 ret = -EBUSY;
723 goto out;
724 }
725
726 /* If it has an init func, it must have an exit func to unload */
727 if (mod->init && !mod->exit) {
728 forced = try_force_unload(flags);
729 if (!forced) {
730 /* This module can't be removed */
731 ret = -EBUSY;
732 goto out;
733 }
734 }
735
736 /* Set this up before setting mod->state */
737 mod->waiter = current;
738
739 /* Stop the machine so refcounts can't move and disable module. */
740 ret = try_stop_module(mod, flags, &forced);
741 if (ret != 0)
742 goto out;
743
744 /* Never wait if forced. */
745 if (!forced && module_refcount(mod) != 0)
746 wait_for_zero_refcount(mod);
747
748 mutex_unlock(&module_mutex);
749 /* Final destruction now noone is using it. */
750 if (mod->exit != NULL)
751 mod->exit();
752 blocking_notifier_call_chain(&module_notify_list,
753 MODULE_STATE_GOING, mod);
754 mutex_lock(&module_mutex);
755 /* Store the name of the last unloaded module for diagnostic purposes */
756 strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
757 free_module(mod);
758
759 out:
760 mutex_unlock(&module_mutex);
761 return ret;
762 }
763
764 static void print_unload_info(struct seq_file *m, struct module *mod)
765 {
766 struct module_use *use;
767 int printed_something = 0;
768
769 seq_printf(m, " %u ", module_refcount(mod));
770
771 /* Always include a trailing , so userspace can differentiate
772 between this and the old multi-field proc format. */
773 list_for_each_entry(use, &mod->modules_which_use_me, list) {
774 printed_something = 1;
775 seq_printf(m, "%s,", use->module_which_uses->name);
776 }
777
778 if (mod->init != NULL && mod->exit == NULL) {
779 printed_something = 1;
780 seq_printf(m, "[permanent],");
781 }
782
783 if (!printed_something)
784 seq_printf(m, "-");
785 }
786
787 void __symbol_put(const char *symbol)
788 {
789 struct module *owner;
790
791 preempt_disable();
792 if (IS_ERR_VALUE(find_symbol(symbol, &owner, NULL, true, false)))
793 BUG();
794 module_put(owner);
795 preempt_enable();
796 }
797 EXPORT_SYMBOL(__symbol_put);
798
799 void symbol_put_addr(void *addr)
800 {
801 struct module *modaddr;
802
803 if (core_kernel_text((unsigned long)addr))
804 return;
805
806 if (!(modaddr = module_text_address((unsigned long)addr)))
807 BUG();
808 module_put(modaddr);
809 }
810 EXPORT_SYMBOL_GPL(symbol_put_addr);
811
812 static ssize_t show_refcnt(struct module_attribute *mattr,
813 struct module *mod, char *buffer)
814 {
815 return sprintf(buffer, "%u\n", module_refcount(mod));
816 }
817
818 static struct module_attribute refcnt = {
819 .attr = { .name = "refcnt", .mode = 0444 },
820 .show = show_refcnt,
821 };
822
823 void module_put(struct module *module)
824 {
825 if (module) {
826 unsigned int cpu = get_cpu();
827 local_dec(&module->ref[cpu].count);
828 /* Maybe they're waiting for us to drop reference? */
829 if (unlikely(!module_is_live(module)))
830 wake_up_process(module->waiter);
831 put_cpu();
832 }
833 }
834 EXPORT_SYMBOL(module_put);
835
836 #else /* !CONFIG_MODULE_UNLOAD */
837 static void print_unload_info(struct seq_file *m, struct module *mod)
838 {
839 /* We don't know the usage count, or what modules are using. */
840 seq_printf(m, " - -");
841 }
842
843 static inline void module_unload_free(struct module *mod)
844 {
845 }
846
847 static inline int use_module(struct module *a, struct module *b)
848 {
849 return strong_try_module_get(b) == 0;
850 }
851
852 static inline void module_unload_init(struct module *mod)
853 {
854 }
855 #endif /* CONFIG_MODULE_UNLOAD */
856
857 static ssize_t show_initstate(struct module_attribute *mattr,
858 struct module *mod, char *buffer)
859 {
860 const char *state = "unknown";
861
862 switch (mod->state) {
863 case MODULE_STATE_LIVE:
864 state = "live";
865 break;
866 case MODULE_STATE_COMING:
867 state = "coming";
868 break;
869 case MODULE_STATE_GOING:
870 state = "going";
871 break;
872 }
873 return sprintf(buffer, "%s\n", state);
874 }
875
876 static struct module_attribute initstate = {
877 .attr = { .name = "initstate", .mode = 0444 },
878 .show = show_initstate,
879 };
880
881 static struct module_attribute *modinfo_attrs[] = {
882 &modinfo_version,
883 &modinfo_srcversion,
884 &initstate,
885 #ifdef CONFIG_MODULE_UNLOAD
886 &refcnt,
887 #endif
888 NULL,
889 };
890
891 static const char vermagic[] = VERMAGIC_STRING;
892
893 static int try_to_force_load(struct module *mod, const char *symname)
894 {
895 #ifdef CONFIG_MODULE_FORCE_LOAD
896 if (!(tainted & TAINT_FORCED_MODULE))
897 printk("%s: no version for \"%s\" found: kernel tainted.\n",
898 mod->name, symname);
899 add_taint_module(mod, TAINT_FORCED_MODULE);
900 return 0;
901 #else
902 return -ENOEXEC;
903 #endif
904 }
905
906 #ifdef CONFIG_MODVERSIONS
907 static int check_version(Elf_Shdr *sechdrs,
908 unsigned int versindex,
909 const char *symname,
910 struct module *mod,
911 const unsigned long *crc)
912 {
913 unsigned int i, num_versions;
914 struct modversion_info *versions;
915
916 /* Exporting module didn't supply crcs? OK, we're already tainted. */
917 if (!crc)
918 return 1;
919
920 versions = (void *) sechdrs[versindex].sh_addr;
921 num_versions = sechdrs[versindex].sh_size
922 / sizeof(struct modversion_info);
923
924 for (i = 0; i < num_versions; i++) {
925 if (strcmp(versions[i].name, symname) != 0)
926 continue;
927
928 if (versions[i].crc == *crc)
929 return 1;
930 DEBUGP("Found checksum %lX vs module %lX\n",
931 *crc, versions[i].crc);
932 goto bad_version;
933 }
934
935 if (!try_to_force_load(mod, symname))
936 return 1;
937
938 bad_version:
939 printk("%s: disagrees about version of symbol %s\n",
940 mod->name, symname);
941 return 0;
942 }
943
944 static inline int check_modstruct_version(Elf_Shdr *sechdrs,
945 unsigned int versindex,
946 struct module *mod)
947 {
948 const unsigned long *crc;
949
950 if (IS_ERR_VALUE(find_symbol("struct_module", NULL, &crc, true, false)))
951 BUG();
952 return check_version(sechdrs, versindex, "struct_module", mod, crc);
953 }
954
955 /* First part is kernel version, which we ignore. */
956 static inline int same_magic(const char *amagic, const char *bmagic)
957 {
958 amagic += strcspn(amagic, " ");
959 bmagic += strcspn(bmagic, " ");
960 return strcmp(amagic, bmagic) == 0;
961 }
962 #else
963 static inline int check_version(Elf_Shdr *sechdrs,
964 unsigned int versindex,
965 const char *symname,
966 struct module *mod,
967 const unsigned long *crc)
968 {
969 return 1;
970 }
971
972 static inline int check_modstruct_version(Elf_Shdr *sechdrs,
973 unsigned int versindex,
974 struct module *mod)
975 {
976 return 1;
977 }
978
979 static inline int same_magic(const char *amagic, const char *bmagic)
980 {
981 return strcmp(amagic, bmagic) == 0;
982 }
983 #endif /* CONFIG_MODVERSIONS */
984
985 /* Resolve a symbol for this module. I.e. if we find one, record usage.
986 Must be holding module_mutex. */
987 static unsigned long resolve_symbol(Elf_Shdr *sechdrs,
988 unsigned int versindex,
989 const char *name,
990 struct module *mod)
991 {
992 struct module *owner;
993 unsigned long ret;
994 const unsigned long *crc;
995
996 ret = find_symbol(name, &owner, &crc,
997 !(mod->taints & TAINT_PROPRIETARY_MODULE), true);
998 if (!IS_ERR_VALUE(ret)) {
999 /* use_module can fail due to OOM,
1000 or module initialization or unloading */
1001 if (!check_version(sechdrs, versindex, name, mod, crc) ||
1002 !use_module(mod, owner))
1003 ret = -EINVAL;
1004 }
1005 return ret;
1006 }
1007
1008 /*
1009 * /sys/module/foo/sections stuff
1010 * J. Corbet <corbet@lwn.net>
1011 */
1012 #if defined(CONFIG_KALLSYMS) && defined(CONFIG_SYSFS)
1013 struct module_sect_attr
1014 {
1015 struct module_attribute mattr;
1016 char *name;
1017 unsigned long address;
1018 };
1019
1020 struct module_sect_attrs
1021 {
1022 struct attribute_group grp;
1023 unsigned int nsections;
1024 struct module_sect_attr attrs[0];
1025 };
1026
1027 static ssize_t module_sect_show(struct module_attribute *mattr,
1028 struct module *mod, char *buf)
1029 {
1030 struct module_sect_attr *sattr =
1031 container_of(mattr, struct module_sect_attr, mattr);
1032 return sprintf(buf, "0x%lx\n", sattr->address);
1033 }
1034
1035 static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
1036 {
1037 unsigned int section;
1038
1039 for (section = 0; section < sect_attrs->nsections; section++)
1040 kfree(sect_attrs->attrs[section].name);
1041 kfree(sect_attrs);
1042 }
1043
1044 static void add_sect_attrs(struct module *mod, unsigned int nsect,
1045 char *secstrings, Elf_Shdr *sechdrs)
1046 {
1047 unsigned int nloaded = 0, i, size[2];
1048 struct module_sect_attrs *sect_attrs;
1049 struct module_sect_attr *sattr;
1050 struct attribute **gattr;
1051
1052 /* Count loaded sections and allocate structures */
1053 for (i = 0; i < nsect; i++)
1054 if (sechdrs[i].sh_flags & SHF_ALLOC)
1055 nloaded++;
1056 size[0] = ALIGN(sizeof(*sect_attrs)
1057 + nloaded * sizeof(sect_attrs->attrs[0]),
1058 sizeof(sect_attrs->grp.attrs[0]));
1059 size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]);
1060 sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
1061 if (sect_attrs == NULL)
1062 return;
1063
1064 /* Setup section attributes. */
1065 sect_attrs->grp.name = "sections";
1066 sect_attrs->grp.attrs = (void *)sect_attrs + size[0];
1067
1068 sect_attrs->nsections = 0;
1069 sattr = &sect_attrs->attrs[0];
1070 gattr = &sect_attrs->grp.attrs[0];
1071 for (i = 0; i < nsect; i++) {
1072 if (! (sechdrs[i].sh_flags & SHF_ALLOC))
1073 continue;
1074 sattr->address = sechdrs[i].sh_addr;
1075 sattr->name = kstrdup(secstrings + sechdrs[i].sh_name,
1076 GFP_KERNEL);
1077 if (sattr->name == NULL)
1078 goto out;
1079 sect_attrs->nsections++;
1080 sattr->mattr.show = module_sect_show;
1081 sattr->mattr.store = NULL;
1082 sattr->mattr.attr.name = sattr->name;
1083 sattr->mattr.attr.mode = S_IRUGO;
1084 *(gattr++) = &(sattr++)->mattr.attr;
1085 }
1086 *gattr = NULL;
1087
1088 if (sysfs_create_group(&mod->mkobj.kobj, &sect_attrs->grp))
1089 goto out;
1090
1091 mod->sect_attrs = sect_attrs;
1092 return;
1093 out:
1094 free_sect_attrs(sect_attrs);
1095 }
1096
1097 static void remove_sect_attrs(struct module *mod)
1098 {
1099 if (mod->sect_attrs) {
1100 sysfs_remove_group(&mod->mkobj.kobj,
1101 &mod->sect_attrs->grp);
1102 /* We are positive that no one is using any sect attrs
1103 * at this point. Deallocate immediately. */
1104 free_sect_attrs(mod->sect_attrs);
1105 mod->sect_attrs = NULL;
1106 }
1107 }
1108
1109 /*
1110 * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
1111 */
1112
1113 struct module_notes_attrs {
1114 struct kobject *dir;
1115 unsigned int notes;
1116 struct bin_attribute attrs[0];
1117 };
1118
1119 static ssize_t module_notes_read(struct kobject *kobj,
1120 struct bin_attribute *bin_attr,
1121 char *buf, loff_t pos, size_t count)
1122 {
1123 /*
1124 * The caller checked the pos and count against our size.
1125 */
1126 memcpy(buf, bin_attr->private + pos, count);
1127 return count;
1128 }
1129
1130 static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
1131 unsigned int i)
1132 {
1133 if (notes_attrs->dir) {
1134 while (i-- > 0)
1135 sysfs_remove_bin_file(notes_attrs->dir,
1136 &notes_attrs->attrs[i]);
1137 kobject_del(notes_attrs->dir);
1138 }
1139 kfree(notes_attrs);
1140 }
1141
1142 static void add_notes_attrs(struct module *mod, unsigned int nsect,
1143 char *secstrings, Elf_Shdr *sechdrs)
1144 {
1145 unsigned int notes, loaded, i;
1146 struct module_notes_attrs *notes_attrs;
1147 struct bin_attribute *nattr;
1148
1149 /* Count notes sections and allocate structures. */
1150 notes = 0;
1151 for (i = 0; i < nsect; i++)
1152 if ((sechdrs[i].sh_flags & SHF_ALLOC) &&
1153 (sechdrs[i].sh_type == SHT_NOTE))
1154 ++notes;
1155
1156 if (notes == 0)
1157 return;
1158
1159 notes_attrs = kzalloc(sizeof(*notes_attrs)
1160 + notes * sizeof(notes_attrs->attrs[0]),
1161 GFP_KERNEL);
1162 if (notes_attrs == NULL)
1163 return;
1164
1165 notes_attrs->notes = notes;
1166 nattr = &notes_attrs->attrs[0];
1167 for (loaded = i = 0; i < nsect; ++i) {
1168 if (!(sechdrs[i].sh_flags & SHF_ALLOC))
1169 continue;
1170 if (sechdrs[i].sh_type == SHT_NOTE) {
1171 nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
1172 nattr->attr.mode = S_IRUGO;
1173 nattr->size = sechdrs[i].sh_size;
1174 nattr->private = (void *) sechdrs[i].sh_addr;
1175 nattr->read = module_notes_read;
1176 ++nattr;
1177 }
1178 ++loaded;
1179 }
1180
1181 notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
1182 if (!notes_attrs->dir)
1183 goto out;
1184
1185 for (i = 0; i < notes; ++i)
1186 if (sysfs_create_bin_file(notes_attrs->dir,
1187 &notes_attrs->attrs[i]))
1188 goto out;
1189
1190 mod->notes_attrs = notes_attrs;
1191 return;
1192
1193 out:
1194 free_notes_attrs(notes_attrs, i);
1195 }
1196
1197 static void remove_notes_attrs(struct module *mod)
1198 {
1199 if (mod->notes_attrs)
1200 free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
1201 }
1202
1203 #else
1204
1205 static inline void add_sect_attrs(struct module *mod, unsigned int nsect,
1206 char *sectstrings, Elf_Shdr *sechdrs)
1207 {
1208 }
1209
1210 static inline void remove_sect_attrs(struct module *mod)
1211 {
1212 }
1213
1214 static inline void add_notes_attrs(struct module *mod, unsigned int nsect,
1215 char *sectstrings, Elf_Shdr *sechdrs)
1216 {
1217 }
1218
1219 static inline void remove_notes_attrs(struct module *mod)
1220 {
1221 }
1222 #endif
1223
1224 #ifdef CONFIG_SYSFS
1225 int module_add_modinfo_attrs(struct module *mod)
1226 {
1227 struct module_attribute *attr;
1228 struct module_attribute *temp_attr;
1229 int error = 0;
1230 int i;
1231
1232 mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
1233 (ARRAY_SIZE(modinfo_attrs) + 1)),
1234 GFP_KERNEL);
1235 if (!mod->modinfo_attrs)
1236 return -ENOMEM;
1237
1238 temp_attr = mod->modinfo_attrs;
1239 for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
1240 if (!attr->test ||
1241 (attr->test && attr->test(mod))) {
1242 memcpy(temp_attr, attr, sizeof(*temp_attr));
1243 error = sysfs_create_file(&mod->mkobj.kobj,&temp_attr->attr);
1244 ++temp_attr;
1245 }
1246 }
1247 return error;
1248 }
1249
1250 void module_remove_modinfo_attrs(struct module *mod)
1251 {
1252 struct module_attribute *attr;
1253 int i;
1254
1255 for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
1256 /* pick a field to test for end of list */
1257 if (!attr->attr.name)
1258 break;
1259 sysfs_remove_file(&mod->mkobj.kobj,&attr->attr);
1260 if (attr->free)
1261 attr->free(mod);
1262 }
1263 kfree(mod->modinfo_attrs);
1264 }
1265
1266 int mod_sysfs_init(struct module *mod)
1267 {
1268 int err;
1269 struct kobject *kobj;
1270
1271 if (!module_sysfs_initialized) {
1272 printk(KERN_ERR "%s: module sysfs not initialized\n",
1273 mod->name);
1274 err = -EINVAL;
1275 goto out;
1276 }
1277
1278 kobj = kset_find_obj(module_kset, mod->name);
1279 if (kobj) {
1280 printk(KERN_ERR "%s: module is already loaded\n", mod->name);
1281 kobject_put(kobj);
1282 err = -EINVAL;
1283 goto out;
1284 }
1285
1286 mod->mkobj.mod = mod;
1287
1288 memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
1289 mod->mkobj.kobj.kset = module_kset;
1290 err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
1291 "%s", mod->name);
1292 if (err)
1293 kobject_put(&mod->mkobj.kobj);
1294
1295 /* delay uevent until full sysfs population */
1296 out:
1297 return err;
1298 }
1299
1300 int mod_sysfs_setup(struct module *mod,
1301 struct kernel_param *kparam,
1302 unsigned int num_params)
1303 {
1304 int err;
1305
1306 mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1307 if (!mod->holders_dir) {
1308 err = -ENOMEM;
1309 goto out_unreg;
1310 }
1311
1312 err = module_param_sysfs_setup(mod, kparam, num_params);
1313 if (err)
1314 goto out_unreg_holders;
1315
1316 err = module_add_modinfo_attrs(mod);
1317 if (err)
1318 goto out_unreg_param;
1319
1320 kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
1321 return 0;
1322
1323 out_unreg_param:
1324 module_param_sysfs_remove(mod);
1325 out_unreg_holders:
1326 kobject_put(mod->holders_dir);
1327 out_unreg:
1328 kobject_put(&mod->mkobj.kobj);
1329 return err;
1330 }
1331 #endif
1332
1333 static void mod_kobject_remove(struct module *mod)
1334 {
1335 module_remove_modinfo_attrs(mod);
1336 module_param_sysfs_remove(mod);
1337 kobject_put(mod->mkobj.drivers_dir);
1338 kobject_put(mod->holders_dir);
1339 kobject_put(&mod->mkobj.kobj);
1340 }
1341
1342 /*
1343 * link the module with the whole machine is stopped with interrupts off
1344 * - this defends against kallsyms not taking locks
1345 */
1346 static int __link_module(void *_mod)
1347 {
1348 struct module *mod = _mod;
1349 list_add(&mod->list, &modules);
1350 return 0;
1351 }
1352
1353 /*
1354 * unlink the module with the whole machine is stopped with interrupts off
1355 * - this defends against kallsyms not taking locks
1356 */
1357 static int __unlink_module(void *_mod)
1358 {
1359 struct module *mod = _mod;
1360 list_del(&mod->list);
1361 return 0;
1362 }
1363
1364 /* Free a module, remove from lists, etc (must hold module_mutex). */
1365 static void free_module(struct module *mod)
1366 {
1367 /* Delete from various lists */
1368 stop_machine_run(__unlink_module, mod, NR_CPUS);
1369 remove_notes_attrs(mod);
1370 remove_sect_attrs(mod);
1371 mod_kobject_remove(mod);
1372
1373 unwind_remove_table(mod->unwind_info, 0);
1374
1375 /* Arch-specific cleanup. */
1376 module_arch_cleanup(mod);
1377
1378 /* Module unload stuff */
1379 module_unload_free(mod);
1380
1381 /* This may be NULL, but that's OK */
1382 module_free(mod, mod->module_init);
1383 kfree(mod->args);
1384 if (mod->percpu)
1385 percpu_modfree(mod->percpu);
1386
1387 /* Free lock-classes: */
1388 lockdep_free_key_range(mod->module_core, mod->core_size);
1389
1390 /* Finally, free the core (containing the module structure) */
1391 module_free(mod, mod->module_core);
1392 }
1393
1394 void *__symbol_get(const char *symbol)
1395 {
1396 struct module *owner;
1397 unsigned long value;
1398
1399 preempt_disable();
1400 value = find_symbol(symbol, &owner, NULL, true, true);
1401 if (IS_ERR_VALUE(value))
1402 value = 0;
1403 else if (strong_try_module_get(owner))
1404 value = 0;
1405 preempt_enable();
1406
1407 return (void *)value;
1408 }
1409 EXPORT_SYMBOL_GPL(__symbol_get);
1410
1411 /*
1412 * Ensure that an exported symbol [global namespace] does not already exist
1413 * in the kernel or in some other module's exported symbol table.
1414 */
1415 static int verify_export_symbols(struct module *mod)
1416 {
1417 unsigned int i;
1418 struct module *owner;
1419 const struct kernel_symbol *s;
1420 struct {
1421 const struct kernel_symbol *sym;
1422 unsigned int num;
1423 } arr[] = {
1424 { mod->syms, mod->num_syms },
1425 { mod->gpl_syms, mod->num_gpl_syms },
1426 { mod->gpl_future_syms, mod->num_gpl_future_syms },
1427 { mod->unused_syms, mod->num_unused_syms },
1428 { mod->unused_gpl_syms, mod->num_unused_gpl_syms },
1429 };
1430
1431 for (i = 0; i < ARRAY_SIZE(arr); i++) {
1432 for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
1433 if (!IS_ERR_VALUE(find_symbol(s->name, &owner,
1434 NULL, true, false))) {
1435 printk(KERN_ERR
1436 "%s: exports duplicate symbol %s"
1437 " (owned by %s)\n",
1438 mod->name, s->name, module_name(owner));
1439 return -ENOEXEC;
1440 }
1441 }
1442 }
1443 return 0;
1444 }
1445
1446 /* Change all symbols so that st_value encodes the pointer directly. */
1447 static int simplify_symbols(Elf_Shdr *sechdrs,
1448 unsigned int symindex,
1449 const char *strtab,
1450 unsigned int versindex,
1451 unsigned int pcpuindex,
1452 struct module *mod)
1453 {
1454 Elf_Sym *sym = (void *)sechdrs[symindex].sh_addr;
1455 unsigned long secbase;
1456 unsigned int i, n = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
1457 int ret = 0;
1458
1459 for (i = 1; i < n; i++) {
1460 switch (sym[i].st_shndx) {
1461 case SHN_COMMON:
1462 /* We compiled with -fno-common. These are not
1463 supposed to happen. */
1464 DEBUGP("Common symbol: %s\n", strtab + sym[i].st_name);
1465 printk("%s: please compile with -fno-common\n",
1466 mod->name);
1467 ret = -ENOEXEC;
1468 break;
1469
1470 case SHN_ABS:
1471 /* Don't need to do anything */
1472 DEBUGP("Absolute symbol: 0x%08lx\n",
1473 (long)sym[i].st_value);
1474 break;
1475
1476 case SHN_UNDEF:
1477 sym[i].st_value
1478 = resolve_symbol(sechdrs, versindex,
1479 strtab + sym[i].st_name, mod);
1480
1481 /* Ok if resolved. */
1482 if (!IS_ERR_VALUE(sym[i].st_value))
1483 break;
1484 /* Ok if weak. */
1485 if (ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
1486 break;
1487
1488 printk(KERN_WARNING "%s: Unknown symbol %s\n",
1489 mod->name, strtab + sym[i].st_name);
1490 ret = -ENOENT;
1491 break;
1492
1493 default:
1494 /* Divert to percpu allocation if a percpu var. */
1495 if (sym[i].st_shndx == pcpuindex)
1496 secbase = (unsigned long)mod->percpu;
1497 else
1498 secbase = sechdrs[sym[i].st_shndx].sh_addr;
1499 sym[i].st_value += secbase;
1500 break;
1501 }
1502 }
1503
1504 return ret;
1505 }
1506
1507 /* Update size with this section: return offset. */
1508 static long get_offset(unsigned long *size, Elf_Shdr *sechdr)
1509 {
1510 long ret;
1511
1512 ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
1513 *size = ret + sechdr->sh_size;
1514 return ret;
1515 }
1516
1517 /* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
1518 might -- code, read-only data, read-write data, small data. Tally
1519 sizes, and place the offsets into sh_entsize fields: high bit means it
1520 belongs in init. */
1521 static void layout_sections(struct module *mod,
1522 const Elf_Ehdr *hdr,
1523 Elf_Shdr *sechdrs,
1524 const char *secstrings)
1525 {
1526 static unsigned long const masks[][2] = {
1527 /* NOTE: all executable code must be the first section
1528 * in this array; otherwise modify the text_size
1529 * finder in the two loops below */
1530 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
1531 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
1532 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
1533 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
1534 };
1535 unsigned int m, i;
1536
1537 for (i = 0; i < hdr->e_shnum; i++)
1538 sechdrs[i].sh_entsize = ~0UL;
1539
1540 DEBUGP("Core section allocation order:\n");
1541 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
1542 for (i = 0; i < hdr->e_shnum; ++i) {
1543 Elf_Shdr *s = &sechdrs[i];
1544
1545 if ((s->sh_flags & masks[m][0]) != masks[m][0]
1546 || (s->sh_flags & masks[m][1])
1547 || s->sh_entsize != ~0UL
1548 || strncmp(secstrings + s->sh_name,
1549 ".init", 5) == 0)
1550 continue;
1551 s->sh_entsize = get_offset(&mod->core_size, s);
1552 DEBUGP("\t%s\n", secstrings + s->sh_name);
1553 }
1554 if (m == 0)
1555 mod->core_text_size = mod->core_size;
1556 }
1557
1558 DEBUGP("Init section allocation order:\n");
1559 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
1560 for (i = 0; i < hdr->e_shnum; ++i) {
1561 Elf_Shdr *s = &sechdrs[i];
1562
1563 if ((s->sh_flags & masks[m][0]) != masks[m][0]
1564 || (s->sh_flags & masks[m][1])
1565 || s->sh_entsize != ~0UL
1566 || strncmp(secstrings + s->sh_name,
1567 ".init", 5) != 0)
1568 continue;
1569 s->sh_entsize = (get_offset(&mod->init_size, s)
1570 | INIT_OFFSET_MASK);
1571 DEBUGP("\t%s\n", secstrings + s->sh_name);
1572 }
1573 if (m == 0)
1574 mod->init_text_size = mod->init_size;
1575 }
1576 }
1577
1578 static void set_license(struct module *mod, const char *license)
1579 {
1580 if (!license)
1581 license = "unspecified";
1582
1583 if (!license_is_gpl_compatible(license)) {
1584 if (!(tainted & TAINT_PROPRIETARY_MODULE))
1585 printk(KERN_WARNING "%s: module license '%s' taints "
1586 "kernel.\n", mod->name, license);
1587 add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
1588 }
1589 }
1590
1591 /* Parse tag=value strings from .modinfo section */
1592 static char *next_string(char *string, unsigned long *secsize)
1593 {
1594 /* Skip non-zero chars */
1595 while (string[0]) {
1596 string++;
1597 if ((*secsize)-- <= 1)
1598 return NULL;
1599 }
1600
1601 /* Skip any zero padding. */
1602 while (!string[0]) {
1603 string++;
1604 if ((*secsize)-- <= 1)
1605 return NULL;
1606 }
1607 return string;
1608 }
1609
1610 static char *get_modinfo(Elf_Shdr *sechdrs,
1611 unsigned int info,
1612 const char *tag)
1613 {
1614 char *p;
1615 unsigned int taglen = strlen(tag);
1616 unsigned long size = sechdrs[info].sh_size;
1617
1618 for (p = (char *)sechdrs[info].sh_addr; p; p = next_string(p, &size)) {
1619 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
1620 return p + taglen + 1;
1621 }
1622 return NULL;
1623 }
1624
1625 static void setup_modinfo(struct module *mod, Elf_Shdr *sechdrs,
1626 unsigned int infoindex)
1627 {
1628 struct module_attribute *attr;
1629 int i;
1630
1631 for (i = 0; (attr = modinfo_attrs[i]); i++) {
1632 if (attr->setup)
1633 attr->setup(mod,
1634 get_modinfo(sechdrs,
1635 infoindex,
1636 attr->attr.name));
1637 }
1638 }
1639
1640 #ifdef CONFIG_KALLSYMS
1641 static int is_exported(const char *name, const struct module *mod)
1642 {
1643 if (!mod && lookup_symbol(name, __start___ksymtab, __stop___ksymtab))
1644 return 1;
1645 else
1646 if (mod && lookup_symbol(name, mod->syms, mod->syms + mod->num_syms))
1647 return 1;
1648 else
1649 return 0;
1650 }
1651
1652 /* As per nm */
1653 static char elf_type(const Elf_Sym *sym,
1654 Elf_Shdr *sechdrs,
1655 const char *secstrings,
1656 struct module *mod)
1657 {
1658 if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
1659 if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
1660 return 'v';
1661 else
1662 return 'w';
1663 }
1664 if (sym->st_shndx == SHN_UNDEF)
1665 return 'U';
1666 if (sym->st_shndx == SHN_ABS)
1667 return 'a';
1668 if (sym->st_shndx >= SHN_LORESERVE)
1669 return '?';
1670 if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
1671 return 't';
1672 if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
1673 && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
1674 if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
1675 return 'r';
1676 else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
1677 return 'g';
1678 else
1679 return 'd';
1680 }
1681 if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
1682 if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
1683 return 's';
1684 else
1685 return 'b';
1686 }
1687 if (strncmp(secstrings + sechdrs[sym->st_shndx].sh_name,
1688 ".debug", strlen(".debug")) == 0)
1689 return 'n';
1690 return '?';
1691 }
1692
1693 static void add_kallsyms(struct module *mod,
1694 Elf_Shdr *sechdrs,
1695 unsigned int symindex,
1696 unsigned int strindex,
1697 const char *secstrings)
1698 {
1699 unsigned int i;
1700
1701 mod->symtab = (void *)sechdrs[symindex].sh_addr;
1702 mod->num_symtab = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
1703 mod->strtab = (void *)sechdrs[strindex].sh_addr;
1704
1705 /* Set types up while we still have access to sections. */
1706 for (i = 0; i < mod->num_symtab; i++)
1707 mod->symtab[i].st_info
1708 = elf_type(&mod->symtab[i], sechdrs, secstrings, mod);
1709 }
1710 #else
1711 static inline void add_kallsyms(struct module *mod,
1712 Elf_Shdr *sechdrs,
1713 unsigned int symindex,
1714 unsigned int strindex,
1715 const char *secstrings)
1716 {
1717 }
1718 #endif /* CONFIG_KALLSYMS */
1719
1720 /* Allocate and load the module: note that size of section 0 is always
1721 zero, and we rely on this for optional sections. */
1722 static struct module *load_module(void __user *umod,
1723 unsigned long len,
1724 const char __user *uargs)
1725 {
1726 Elf_Ehdr *hdr;
1727 Elf_Shdr *sechdrs;
1728 char *secstrings, *args, *modmagic, *strtab = NULL;
1729 unsigned int i;
1730 unsigned int symindex = 0;
1731 unsigned int strindex = 0;
1732 unsigned int setupindex;
1733 unsigned int exindex;
1734 unsigned int exportindex;
1735 unsigned int modindex;
1736 unsigned int obsparmindex;
1737 unsigned int infoindex;
1738 unsigned int gplindex;
1739 unsigned int crcindex;
1740 unsigned int gplcrcindex;
1741 unsigned int versindex;
1742 unsigned int pcpuindex;
1743 unsigned int gplfutureindex;
1744 unsigned int gplfuturecrcindex;
1745 unsigned int unwindex = 0;
1746 unsigned int unusedindex;
1747 unsigned int unusedcrcindex;
1748 unsigned int unusedgplindex;
1749 unsigned int unusedgplcrcindex;
1750 unsigned int markersindex;
1751 unsigned int markersstringsindex;
1752 struct module *mod;
1753 long err = 0;
1754 void *percpu = NULL, *ptr = NULL; /* Stops spurious gcc warning */
1755 struct exception_table_entry *extable;
1756 mm_segment_t old_fs;
1757
1758 DEBUGP("load_module: umod=%p, len=%lu, uargs=%p\n",
1759 umod, len, uargs);
1760 if (len < sizeof(*hdr))
1761 return ERR_PTR(-ENOEXEC);
1762
1763 /* Suck in entire file: we'll want most of it. */
1764 /* vmalloc barfs on "unusual" numbers. Check here */
1765 if (len > 64 * 1024 * 1024 || (hdr = vmalloc(len)) == NULL)
1766 return ERR_PTR(-ENOMEM);
1767 if (copy_from_user(hdr, umod, len) != 0) {
1768 err = -EFAULT;
1769 goto free_hdr;
1770 }
1771
1772 /* Sanity checks against insmoding binaries or wrong arch,
1773 weird elf version */
1774 if (memcmp(hdr->e_ident, ELFMAG, 4) != 0
1775 || hdr->e_type != ET_REL
1776 || !elf_check_arch(hdr)
1777 || hdr->e_shentsize != sizeof(*sechdrs)) {
1778 err = -ENOEXEC;
1779 goto free_hdr;
1780 }
1781
1782 if (len < hdr->e_shoff + hdr->e_shnum * sizeof(Elf_Shdr))
1783 goto truncated;
1784
1785 /* Convenience variables */
1786 sechdrs = (void *)hdr + hdr->e_shoff;
1787 secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
1788 sechdrs[0].sh_addr = 0;
1789
1790 for (i = 1; i < hdr->e_shnum; i++) {
1791 if (sechdrs[i].sh_type != SHT_NOBITS
1792 && len < sechdrs[i].sh_offset + sechdrs[i].sh_size)
1793 goto truncated;
1794
1795 /* Mark all sections sh_addr with their address in the
1796 temporary image. */
1797 sechdrs[i].sh_addr = (size_t)hdr + sechdrs[i].sh_offset;
1798
1799 /* Internal symbols and strings. */
1800 if (sechdrs[i].sh_type == SHT_SYMTAB) {
1801 symindex = i;
1802 strindex = sechdrs[i].sh_link;
1803 strtab = (char *)hdr + sechdrs[strindex].sh_offset;
1804 }
1805 #ifndef CONFIG_MODULE_UNLOAD
1806 /* Don't load .exit sections */
1807 if (strncmp(secstrings+sechdrs[i].sh_name, ".exit", 5) == 0)
1808 sechdrs[i].sh_flags &= ~(unsigned long)SHF_ALLOC;
1809 #endif
1810 }
1811
1812 modindex = find_sec(hdr, sechdrs, secstrings,
1813 ".gnu.linkonce.this_module");
1814 if (!modindex) {
1815 printk(KERN_WARNING "No module found in object\n");
1816 err = -ENOEXEC;
1817 goto free_hdr;
1818 }
1819 mod = (void *)sechdrs[modindex].sh_addr;
1820
1821 if (symindex == 0) {
1822 printk(KERN_WARNING "%s: module has no symbols (stripped?)\n",
1823 mod->name);
1824 err = -ENOEXEC;
1825 goto free_hdr;
1826 }
1827
1828 /* Optional sections */
1829 exportindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab");
1830 gplindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_gpl");
1831 gplfutureindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_gpl_future");
1832 unusedindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_unused");
1833 unusedgplindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_unused_gpl");
1834 crcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab");
1835 gplcrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_gpl");
1836 gplfuturecrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_gpl_future");
1837 unusedcrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_unused");
1838 unusedgplcrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_unused_gpl");
1839 setupindex = find_sec(hdr, sechdrs, secstrings, "__param");
1840 exindex = find_sec(hdr, sechdrs, secstrings, "__ex_table");
1841 obsparmindex = find_sec(hdr, sechdrs, secstrings, "__obsparm");
1842 versindex = find_sec(hdr, sechdrs, secstrings, "__versions");
1843 infoindex = find_sec(hdr, sechdrs, secstrings, ".modinfo");
1844 pcpuindex = find_pcpusec(hdr, sechdrs, secstrings);
1845 #ifdef ARCH_UNWIND_SECTION_NAME
1846 unwindex = find_sec(hdr, sechdrs, secstrings, ARCH_UNWIND_SECTION_NAME);
1847 #endif
1848
1849 /* Don't keep modinfo and version sections. */
1850 sechdrs[infoindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
1851 sechdrs[versindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
1852 #ifdef CONFIG_KALLSYMS
1853 /* Keep symbol and string tables for decoding later. */
1854 sechdrs[symindex].sh_flags |= SHF_ALLOC;
1855 sechdrs[strindex].sh_flags |= SHF_ALLOC;
1856 #endif
1857 if (unwindex)
1858 sechdrs[unwindex].sh_flags |= SHF_ALLOC;
1859
1860 /* Check module struct version now, before we try to use module. */
1861 if (!check_modstruct_version(sechdrs, versindex, mod)) {
1862 err = -ENOEXEC;
1863 goto free_hdr;
1864 }
1865
1866 modmagic = get_modinfo(sechdrs, infoindex, "vermagic");
1867 /* This is allowed: modprobe --force will invalidate it. */
1868 if (!modmagic) {
1869 err = try_to_force_load(mod, "magic");
1870 if (err)
1871 goto free_hdr;
1872 } else if (!same_magic(modmagic, vermagic)) {
1873 printk(KERN_ERR "%s: version magic '%s' should be '%s'\n",
1874 mod->name, modmagic, vermagic);
1875 err = -ENOEXEC;
1876 goto free_hdr;
1877 }
1878
1879 /* Now copy in args */
1880 args = strndup_user(uargs, ~0UL >> 1);
1881 if (IS_ERR(args)) {
1882 err = PTR_ERR(args);
1883 goto free_hdr;
1884 }
1885
1886 if (find_module(mod->name)) {
1887 err = -EEXIST;
1888 goto free_mod;
1889 }
1890
1891 mod->state = MODULE_STATE_COMING;
1892
1893 /* Allow arches to frob section contents and sizes. */
1894 err = module_frob_arch_sections(hdr, sechdrs, secstrings, mod);
1895 if (err < 0)
1896 goto free_mod;
1897
1898 if (pcpuindex) {
1899 /* We have a special allocation for this section. */
1900 percpu = percpu_modalloc(sechdrs[pcpuindex].sh_size,
1901 sechdrs[pcpuindex].sh_addralign,
1902 mod->name);
1903 if (!percpu) {
1904 err = -ENOMEM;
1905 goto free_mod;
1906 }
1907 sechdrs[pcpuindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
1908 mod->percpu = percpu;
1909 }
1910
1911 /* Determine total sizes, and put offsets in sh_entsize. For now
1912 this is done generically; there doesn't appear to be any
1913 special cases for the architectures. */
1914 layout_sections(mod, hdr, sechdrs, secstrings);
1915
1916 /* Do the allocs. */
1917 ptr = module_alloc(mod->core_size);
1918 if (!ptr) {
1919 err = -ENOMEM;
1920 goto free_percpu;
1921 }
1922 memset(ptr, 0, mod->core_size);
1923 mod->module_core = ptr;
1924
1925 ptr = module_alloc(mod->init_size);
1926 if (!ptr && mod->init_size) {
1927 err = -ENOMEM;
1928 goto free_core;
1929 }
1930 memset(ptr, 0, mod->init_size);
1931 mod->module_init = ptr;
1932
1933 /* Transfer each section which specifies SHF_ALLOC */
1934 DEBUGP("final section addresses:\n");
1935 for (i = 0; i < hdr->e_shnum; i++) {
1936 void *dest;
1937
1938 if (!(sechdrs[i].sh_flags & SHF_ALLOC))
1939 continue;
1940
1941 if (sechdrs[i].sh_entsize & INIT_OFFSET_MASK)
1942 dest = mod->module_init
1943 + (sechdrs[i].sh_entsize & ~INIT_OFFSET_MASK);
1944 else
1945 dest = mod->module_core + sechdrs[i].sh_entsize;
1946
1947 if (sechdrs[i].sh_type != SHT_NOBITS)
1948 memcpy(dest, (void *)sechdrs[i].sh_addr,
1949 sechdrs[i].sh_size);
1950 /* Update sh_addr to point to copy in image. */
1951 sechdrs[i].sh_addr = (unsigned long)dest;
1952 DEBUGP("\t0x%lx %s\n", sechdrs[i].sh_addr, secstrings + sechdrs[i].sh_name);
1953 }
1954 /* Module has been moved. */
1955 mod = (void *)sechdrs[modindex].sh_addr;
1956
1957 /* Now we've moved module, initialize linked lists, etc. */
1958 module_unload_init(mod);
1959
1960 /* add kobject, so we can reference it. */
1961 err = mod_sysfs_init(mod);
1962 if (err)
1963 goto free_unload;
1964
1965 /* Set up license info based on the info section */
1966 set_license(mod, get_modinfo(sechdrs, infoindex, "license"));
1967
1968 /*
1969 * ndiswrapper is under GPL by itself, but loads proprietary modules.
1970 * Don't use add_taint_module(), as it would prevent ndiswrapper from
1971 * using GPL-only symbols it needs.
1972 */
1973 if (strcmp(mod->name, "ndiswrapper") == 0)
1974 add_taint(TAINT_PROPRIETARY_MODULE);
1975
1976 /* driverloader was caught wrongly pretending to be under GPL */
1977 if (strcmp(mod->name, "driverloader") == 0)
1978 add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
1979
1980 /* Set up MODINFO_ATTR fields */
1981 setup_modinfo(mod, sechdrs, infoindex);
1982
1983 /* Fix up syms, so that st_value is a pointer to location. */
1984 err = simplify_symbols(sechdrs, symindex, strtab, versindex, pcpuindex,
1985 mod);
1986 if (err < 0)
1987 goto cleanup;
1988
1989 /* Set up EXPORTed & EXPORT_GPLed symbols (section 0 is 0 length) */
1990 mod->num_syms = sechdrs[exportindex].sh_size / sizeof(*mod->syms);
1991 mod->syms = (void *)sechdrs[exportindex].sh_addr;
1992 if (crcindex)
1993 mod->crcs = (void *)sechdrs[crcindex].sh_addr;
1994 mod->num_gpl_syms = sechdrs[gplindex].sh_size / sizeof(*mod->gpl_syms);
1995 mod->gpl_syms = (void *)sechdrs[gplindex].sh_addr;
1996 if (gplcrcindex)
1997 mod->gpl_crcs = (void *)sechdrs[gplcrcindex].sh_addr;
1998 mod->num_gpl_future_syms = sechdrs[gplfutureindex].sh_size /
1999 sizeof(*mod->gpl_future_syms);
2000 mod->num_unused_syms = sechdrs[unusedindex].sh_size /
2001 sizeof(*mod->unused_syms);
2002 mod->num_unused_gpl_syms = sechdrs[unusedgplindex].sh_size /
2003 sizeof(*mod->unused_gpl_syms);
2004 mod->gpl_future_syms = (void *)sechdrs[gplfutureindex].sh_addr;
2005 if (gplfuturecrcindex)
2006 mod->gpl_future_crcs = (void *)sechdrs[gplfuturecrcindex].sh_addr;
2007
2008 mod->unused_syms = (void *)sechdrs[unusedindex].sh_addr;
2009 if (unusedcrcindex)
2010 mod->unused_crcs = (void *)sechdrs[unusedcrcindex].sh_addr;
2011 mod->unused_gpl_syms = (void *)sechdrs[unusedgplindex].sh_addr;
2012 if (unusedgplcrcindex)
2013 mod->unused_gpl_crcs
2014 = (void *)sechdrs[unusedgplcrcindex].sh_addr;
2015
2016 #ifdef CONFIG_MODVERSIONS
2017 if ((mod->num_syms && !crcindex) ||
2018 (mod->num_gpl_syms && !gplcrcindex) ||
2019 (mod->num_gpl_future_syms && !gplfuturecrcindex) ||
2020 (mod->num_unused_syms && !unusedcrcindex) ||
2021 (mod->num_unused_gpl_syms && !unusedgplcrcindex)) {
2022 printk(KERN_WARNING "%s: No versions for exported symbols.\n", mod->name);
2023 err = try_to_force_load(mod, "nocrc");
2024 if (err)
2025 goto cleanup;
2026 }
2027 #endif
2028 markersindex = find_sec(hdr, sechdrs, secstrings, "__markers");
2029 markersstringsindex = find_sec(hdr, sechdrs, secstrings,
2030 "__markers_strings");
2031
2032 /* Now do relocations. */
2033 for (i = 1; i < hdr->e_shnum; i++) {
2034 const char *strtab = (char *)sechdrs[strindex].sh_addr;
2035 unsigned int info = sechdrs[i].sh_info;
2036
2037 /* Not a valid relocation section? */
2038 if (info >= hdr->e_shnum)
2039 continue;
2040
2041 /* Don't bother with non-allocated sections */
2042 if (!(sechdrs[info].sh_flags & SHF_ALLOC))
2043 continue;
2044
2045 if (sechdrs[i].sh_type == SHT_REL)
2046 err = apply_relocate(sechdrs, strtab, symindex, i,mod);
2047 else if (sechdrs[i].sh_type == SHT_RELA)
2048 err = apply_relocate_add(sechdrs, strtab, symindex, i,
2049 mod);
2050 if (err < 0)
2051 goto cleanup;
2052 }
2053 #ifdef CONFIG_MARKERS
2054 mod->markers = (void *)sechdrs[markersindex].sh_addr;
2055 mod->num_markers =
2056 sechdrs[markersindex].sh_size / sizeof(*mod->markers);
2057 #endif
2058
2059 /* Find duplicate symbols */
2060 err = verify_export_symbols(mod);
2061
2062 if (err < 0)
2063 goto cleanup;
2064
2065 /* Set up and sort exception table */
2066 mod->num_exentries = sechdrs[exindex].sh_size / sizeof(*mod->extable);
2067 mod->extable = extable = (void *)sechdrs[exindex].sh_addr;
2068 sort_extable(extable, extable + mod->num_exentries);
2069
2070 /* Finally, copy percpu area over. */
2071 percpu_modcopy(mod->percpu, (void *)sechdrs[pcpuindex].sh_addr,
2072 sechdrs[pcpuindex].sh_size);
2073
2074 add_kallsyms(mod, sechdrs, symindex, strindex, secstrings);
2075
2076 #ifdef CONFIG_MARKERS
2077 if (!mod->taints)
2078 marker_update_probe_range(mod->markers,
2079 mod->markers + mod->num_markers);
2080 #endif
2081 err = module_finalize(hdr, sechdrs, mod);
2082 if (err < 0)
2083 goto cleanup;
2084
2085 /* flush the icache in correct context */
2086 old_fs = get_fs();
2087 set_fs(KERNEL_DS);
2088
2089 /*
2090 * Flush the instruction cache, since we've played with text.
2091 * Do it before processing of module parameters, so the module
2092 * can provide parameter accessor functions of its own.
2093 */
2094 if (mod->module_init)
2095 flush_icache_range((unsigned long)mod->module_init,
2096 (unsigned long)mod->module_init
2097 + mod->init_size);
2098 flush_icache_range((unsigned long)mod->module_core,
2099 (unsigned long)mod->module_core + mod->core_size);
2100
2101 set_fs(old_fs);
2102
2103 mod->args = args;
2104 if (obsparmindex)
2105 printk(KERN_WARNING "%s: Ignoring obsolete parameters\n",
2106 mod->name);
2107
2108 /* Now sew it into the lists so we can get lockdep and oops
2109 * info during argument parsing. Noone should access us, since
2110 * strong_try_module_get() will fail. */
2111 stop_machine_run(__link_module, mod, NR_CPUS);
2112
2113 /* Size of section 0 is 0, so this works well if no params */
2114 err = parse_args(mod->name, mod->args,
2115 (struct kernel_param *)
2116 sechdrs[setupindex].sh_addr,
2117 sechdrs[setupindex].sh_size
2118 / sizeof(struct kernel_param),
2119 NULL);
2120 if (err < 0)
2121 goto unlink;
2122
2123 err = mod_sysfs_setup(mod,
2124 (struct kernel_param *)
2125 sechdrs[setupindex].sh_addr,
2126 sechdrs[setupindex].sh_size
2127 / sizeof(struct kernel_param));
2128 if (err < 0)
2129 goto unlink;
2130 add_sect_attrs(mod, hdr->e_shnum, secstrings, sechdrs);
2131 add_notes_attrs(mod, hdr->e_shnum, secstrings, sechdrs);
2132
2133 /* Size of section 0 is 0, so this works well if no unwind info. */
2134 mod->unwind_info = unwind_add_table(mod,
2135 (void *)sechdrs[unwindex].sh_addr,
2136 sechdrs[unwindex].sh_size);
2137
2138 /* Get rid of temporary copy */
2139 vfree(hdr);
2140
2141 /* Done! */
2142 return mod;
2143
2144 unlink:
2145 stop_machine_run(__unlink_module, mod, NR_CPUS);
2146 module_arch_cleanup(mod);
2147 cleanup:
2148 kobject_del(&mod->mkobj.kobj);
2149 kobject_put(&mod->mkobj.kobj);
2150 free_unload:
2151 module_unload_free(mod);
2152 module_free(mod, mod->module_init);
2153 free_core:
2154 module_free(mod, mod->module_core);
2155 free_percpu:
2156 if (percpu)
2157 percpu_modfree(percpu);
2158 free_mod:
2159 kfree(args);
2160 free_hdr:
2161 vfree(hdr);
2162 return ERR_PTR(err);
2163
2164 truncated:
2165 printk(KERN_ERR "Module len %lu truncated\n", len);
2166 err = -ENOEXEC;
2167 goto free_hdr;
2168 }
2169
2170 /* This is where the real work happens */
2171 asmlinkage long
2172 sys_init_module(void __user *umod,
2173 unsigned long len,
2174 const char __user *uargs)
2175 {
2176 struct module *mod;
2177 int ret = 0;
2178
2179 /* Must have permission */
2180 if (!capable(CAP_SYS_MODULE))
2181 return -EPERM;
2182
2183 /* Only one module load at a time, please */
2184 if (mutex_lock_interruptible(&module_mutex) != 0)
2185 return -EINTR;
2186
2187 /* Do all the hard work */
2188 mod = load_module(umod, len, uargs);
2189 if (IS_ERR(mod)) {
2190 mutex_unlock(&module_mutex);
2191 return PTR_ERR(mod);
2192 }
2193
2194 /* Drop lock so they can recurse */
2195 mutex_unlock(&module_mutex);
2196
2197 blocking_notifier_call_chain(&module_notify_list,
2198 MODULE_STATE_COMING, mod);
2199
2200 /* Start the module */
2201 if (mod->init != NULL)
2202 ret = mod->init();
2203 if (ret < 0) {
2204 /* Init routine failed: abort. Try to protect us from
2205 buggy refcounters. */
2206 mod->state = MODULE_STATE_GOING;
2207 synchronize_sched();
2208 module_put(mod);
2209 blocking_notifier_call_chain(&module_notify_list,
2210 MODULE_STATE_GOING, mod);
2211 mutex_lock(&module_mutex);
2212 free_module(mod);
2213 mutex_unlock(&module_mutex);
2214 wake_up(&module_wq);
2215 return ret;
2216 }
2217 if (ret > 0) {
2218 printk(KERN_WARNING "%s: '%s'->init suspiciously returned %d, "
2219 "it should follow 0/-E convention\n"
2220 KERN_WARNING "%s: loading module anyway...\n",
2221 __func__, mod->name, ret,
2222 __func__);
2223 dump_stack();
2224 }
2225
2226 /* Now it's a first class citizen! Wake up anyone waiting for it. */
2227 mod->state = MODULE_STATE_LIVE;
2228 wake_up(&module_wq);
2229
2230 mutex_lock(&module_mutex);
2231 /* Drop initial reference. */
2232 module_put(mod);
2233 unwind_remove_table(mod->unwind_info, 1);
2234 module_free(mod, mod->module_init);
2235 mod->module_init = NULL;
2236 mod->init_size = 0;
2237 mod->init_text_size = 0;
2238 mutex_unlock(&module_mutex);
2239
2240 return 0;
2241 }
2242
2243 static inline int within(unsigned long addr, void *start, unsigned long size)
2244 {
2245 return ((void *)addr >= start && (void *)addr < start + size);
2246 }
2247
2248 #ifdef CONFIG_KALLSYMS
2249 /*
2250 * This ignores the intensely annoying "mapping symbols" found
2251 * in ARM ELF files: $a, $t and $d.
2252 */
2253 static inline int is_arm_mapping_symbol(const char *str)
2254 {
2255 return str[0] == '$' && strchr("atd", str[1])
2256 && (str[2] == '\0' || str[2] == '.');
2257 }
2258
2259 static const char *get_ksymbol(struct module *mod,
2260 unsigned long addr,
2261 unsigned long *size,
2262 unsigned long *offset)
2263 {
2264 unsigned int i, best = 0;
2265 unsigned long nextval;
2266
2267 /* At worse, next value is at end of module */
2268 if (within(addr, mod->module_init, mod->init_size))
2269 nextval = (unsigned long)mod->module_init+mod->init_text_size;
2270 else
2271 nextval = (unsigned long)mod->module_core+mod->core_text_size;
2272
2273 /* Scan for closest preceeding symbol, and next symbol. (ELF
2274 starts real symbols at 1). */
2275 for (i = 1; i < mod->num_symtab; i++) {
2276 if (mod->symtab[i].st_shndx == SHN_UNDEF)
2277 continue;
2278
2279 /* We ignore unnamed symbols: they're uninformative
2280 * and inserted at a whim. */
2281 if (mod->symtab[i].st_value <= addr
2282 && mod->symtab[i].st_value > mod->symtab[best].st_value
2283 && *(mod->strtab + mod->symtab[i].st_name) != '\0'
2284 && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
2285 best = i;
2286 if (mod->symtab[i].st_value > addr
2287 && mod->symtab[i].st_value < nextval
2288 && *(mod->strtab + mod->symtab[i].st_name) != '\0'
2289 && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
2290 nextval = mod->symtab[i].st_value;
2291 }
2292
2293 if (!best)
2294 return NULL;
2295
2296 if (size)
2297 *size = nextval - mod->symtab[best].st_value;
2298 if (offset)
2299 *offset = addr - mod->symtab[best].st_value;
2300 return mod->strtab + mod->symtab[best].st_name;
2301 }
2302
2303 /* For kallsyms to ask for address resolution. NULL means not found. Careful
2304 * not to lock to avoid deadlock on oopses, simply disable preemption. */
2305 const char *module_address_lookup(unsigned long addr,
2306 unsigned long *size,
2307 unsigned long *offset,
2308 char **modname,
2309 char *namebuf)
2310 {
2311 struct module *mod;
2312 const char *ret = NULL;
2313
2314 preempt_disable();
2315 list_for_each_entry(mod, &modules, list) {
2316 if (within(addr, mod->module_init, mod->init_size)
2317 || within(addr, mod->module_core, mod->core_size)) {
2318 if (modname)
2319 *modname = mod->name;
2320 ret = get_ksymbol(mod, addr, size, offset);
2321 break;
2322 }
2323 }
2324 /* Make a copy in here where it's safe */
2325 if (ret) {
2326 strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
2327 ret = namebuf;
2328 }
2329 preempt_enable();
2330 return ret;
2331 }
2332
2333 int lookup_module_symbol_name(unsigned long addr, char *symname)
2334 {
2335 struct module *mod;
2336
2337 preempt_disable();
2338 list_for_each_entry(mod, &modules, list) {
2339 if (within(addr, mod->module_init, mod->init_size) ||
2340 within(addr, mod->module_core, mod->core_size)) {
2341 const char *sym;
2342
2343 sym = get_ksymbol(mod, addr, NULL, NULL);
2344 if (!sym)
2345 goto out;
2346 strlcpy(symname, sym, KSYM_NAME_LEN);
2347 preempt_enable();
2348 return 0;
2349 }
2350 }
2351 out:
2352 preempt_enable();
2353 return -ERANGE;
2354 }
2355
2356 int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
2357 unsigned long *offset, char *modname, char *name)
2358 {
2359 struct module *mod;
2360
2361 preempt_disable();
2362 list_for_each_entry(mod, &modules, list) {
2363 if (within(addr, mod->module_init, mod->init_size) ||
2364 within(addr, mod->module_core, mod->core_size)) {
2365 const char *sym;
2366
2367 sym = get_ksymbol(mod, addr, size, offset);
2368 if (!sym)
2369 goto out;
2370 if (modname)
2371 strlcpy(modname, mod->name, MODULE_NAME_LEN);
2372 if (name)
2373 strlcpy(name, sym, KSYM_NAME_LEN);
2374 preempt_enable();
2375 return 0;
2376 }
2377 }
2378 out:
2379 preempt_enable();
2380 return -ERANGE;
2381 }
2382
2383 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
2384 char *name, char *module_name, int *exported)
2385 {
2386 struct module *mod;
2387
2388 preempt_disable();
2389 list_for_each_entry(mod, &modules, list) {
2390 if (symnum < mod->num_symtab) {
2391 *value = mod->symtab[symnum].st_value;
2392 *type = mod->symtab[symnum].st_info;
2393 strlcpy(name, mod->strtab + mod->symtab[symnum].st_name,
2394 KSYM_NAME_LEN);
2395 strlcpy(module_name, mod->name, MODULE_NAME_LEN);
2396 *exported = is_exported(name, mod);
2397 preempt_enable();
2398 return 0;
2399 }
2400 symnum -= mod->num_symtab;
2401 }
2402 preempt_enable();
2403 return -ERANGE;
2404 }
2405
2406 static unsigned long mod_find_symname(struct module *mod, const char *name)
2407 {
2408 unsigned int i;
2409
2410 for (i = 0; i < mod->num_symtab; i++)
2411 if (strcmp(name, mod->strtab+mod->symtab[i].st_name) == 0 &&
2412 mod->symtab[i].st_info != 'U')
2413 return mod->symtab[i].st_value;
2414 return 0;
2415 }
2416
2417 /* Look for this name: can be of form module:name. */
2418 unsigned long module_kallsyms_lookup_name(const char *name)
2419 {
2420 struct module *mod;
2421 char *colon;
2422 unsigned long ret = 0;
2423
2424 /* Don't lock: we're in enough trouble already. */
2425 preempt_disable();
2426 if ((colon = strchr(name, ':')) != NULL) {
2427 *colon = '\0';
2428 if ((mod = find_module(name)) != NULL)
2429 ret = mod_find_symname(mod, colon+1);
2430 *colon = ':';
2431 } else {
2432 list_for_each_entry(mod, &modules, list)
2433 if ((ret = mod_find_symname(mod, name)) != 0)
2434 break;
2435 }
2436 preempt_enable();
2437 return ret;
2438 }
2439 #endif /* CONFIG_KALLSYMS */
2440
2441 /* Called by the /proc file system to return a list of modules. */
2442 static void *m_start(struct seq_file *m, loff_t *pos)
2443 {
2444 mutex_lock(&module_mutex);
2445 return seq_list_start(&modules, *pos);
2446 }
2447
2448 static void *m_next(struct seq_file *m, void *p, loff_t *pos)
2449 {
2450 return seq_list_next(p, &modules, pos);
2451 }
2452
2453 static void m_stop(struct seq_file *m, void *p)
2454 {
2455 mutex_unlock(&module_mutex);
2456 }
2457
2458 static char *module_flags(struct module *mod, char *buf)
2459 {
2460 int bx = 0;
2461
2462 if (mod->taints ||
2463 mod->state == MODULE_STATE_GOING ||
2464 mod->state == MODULE_STATE_COMING) {
2465 buf[bx++] = '(';
2466 if (mod->taints & TAINT_PROPRIETARY_MODULE)
2467 buf[bx++] = 'P';
2468 if (mod->taints & TAINT_FORCED_MODULE)
2469 buf[bx++] = 'F';
2470 /*
2471 * TAINT_FORCED_RMMOD: could be added.
2472 * TAINT_UNSAFE_SMP, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't
2473 * apply to modules.
2474 */
2475
2476 /* Show a - for module-is-being-unloaded */
2477 if (mod->state == MODULE_STATE_GOING)
2478 buf[bx++] = '-';
2479 /* Show a + for module-is-being-loaded */
2480 if (mod->state == MODULE_STATE_COMING)
2481 buf[bx++] = '+';
2482 buf[bx++] = ')';
2483 }
2484 buf[bx] = '\0';
2485
2486 return buf;
2487 }
2488
2489 static int m_show(struct seq_file *m, void *p)
2490 {
2491 struct module *mod = list_entry(p, struct module, list);
2492 char buf[8];
2493
2494 seq_printf(m, "%s %lu",
2495 mod->name, mod->init_size + mod->core_size);
2496 print_unload_info(m, mod);
2497
2498 /* Informative for users. */
2499 seq_printf(m, " %s",
2500 mod->state == MODULE_STATE_GOING ? "Unloading":
2501 mod->state == MODULE_STATE_COMING ? "Loading":
2502 "Live");
2503 /* Used by oprofile and other similar tools. */
2504 seq_printf(m, " 0x%p", mod->module_core);
2505
2506 /* Taints info */
2507 if (mod->taints)
2508 seq_printf(m, " %s", module_flags(mod, buf));
2509
2510 seq_printf(m, "\n");
2511 return 0;
2512 }
2513
2514 /* Format: modulename size refcount deps address
2515
2516 Where refcount is a number or -, and deps is a comma-separated list
2517 of depends or -.
2518 */
2519 const struct seq_operations modules_op = {
2520 .start = m_start,
2521 .next = m_next,
2522 .stop = m_stop,
2523 .show = m_show
2524 };
2525
2526 /* Given an address, look for it in the module exception tables. */
2527 const struct exception_table_entry *search_module_extables(unsigned long addr)
2528 {
2529 const struct exception_table_entry *e = NULL;
2530 struct module *mod;
2531
2532 preempt_disable();
2533 list_for_each_entry(mod, &modules, list) {
2534 if (mod->num_exentries == 0)
2535 continue;
2536
2537 e = search_extable(mod->extable,
2538 mod->extable + mod->num_exentries - 1,
2539 addr);
2540 if (e)
2541 break;
2542 }
2543 preempt_enable();
2544
2545 /* Now, if we found one, we are running inside it now, hence
2546 we cannot unload the module, hence no refcnt needed. */
2547 return e;
2548 }
2549
2550 /*
2551 * Is this a valid module address?
2552 */
2553 int is_module_address(unsigned long addr)
2554 {
2555 struct module *mod;
2556
2557 preempt_disable();
2558
2559 list_for_each_entry(mod, &modules, list) {
2560 if (within(addr, mod->module_core, mod->core_size)) {
2561 preempt_enable();
2562 return 1;
2563 }
2564 }
2565
2566 preempt_enable();
2567
2568 return 0;
2569 }
2570
2571
2572 /* Is this a valid kernel address? */
2573 struct module *__module_text_address(unsigned long addr)
2574 {
2575 struct module *mod;
2576
2577 list_for_each_entry(mod, &modules, list)
2578 if (within(addr, mod->module_init, mod->init_text_size)
2579 || within(addr, mod->module_core, mod->core_text_size))
2580 return mod;
2581 return NULL;
2582 }
2583
2584 struct module *module_text_address(unsigned long addr)
2585 {
2586 struct module *mod;
2587
2588 preempt_disable();
2589 mod = __module_text_address(addr);
2590 preempt_enable();
2591
2592 return mod;
2593 }
2594
2595 /* Don't grab lock, we're oopsing. */
2596 void print_modules(void)
2597 {
2598 struct module *mod;
2599 char buf[8];
2600
2601 printk("Modules linked in:");
2602 list_for_each_entry(mod, &modules, list)
2603 printk(" %s%s", mod->name, module_flags(mod, buf));
2604 if (last_unloaded_module[0])
2605 printk(" [last unloaded: %s]", last_unloaded_module);
2606 printk("\n");
2607 }
2608
2609 #ifdef CONFIG_MODVERSIONS
2610 /* Generate the signature for struct module here, too, for modversions. */
2611 void struct_module(struct module *mod) { return; }
2612 EXPORT_SYMBOL(struct_module);
2613 #endif
2614
2615 #ifdef CONFIG_MARKERS
2616 void module_update_markers(void)
2617 {
2618 struct module *mod;
2619
2620 mutex_lock(&module_mutex);
2621 list_for_each_entry(mod, &modules, list)
2622 if (!mod->taints)
2623 marker_update_probe_range(mod->markers,
2624 mod->markers + mod->num_markers);
2625 mutex_unlock(&module_mutex);
2626 }
2627 #endif
Linux with added FPC-III support