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ia64/pv_ops/xen: implement xen pv_time_ops.
[pv_ops_mirror.git] / kernel / module.c
blobf5e9491ef7ac2ed9d9473ded84c37f5018ed722c
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 /* No versions at all? modprobe --force does this. */
921 if (versindex == 0)
922 return try_to_force_load(mod, symname) == 0;
923
924 versions = (void *) sechdrs[versindex].sh_addr;
925 num_versions = sechdrs[versindex].sh_size
926 / sizeof(struct modversion_info);
927
928 for (i = 0; i < num_versions; i++) {
929 if (strcmp(versions[i].name, symname) != 0)
930 continue;
931
932 if (versions[i].crc == *crc)
933 return 1;
934 DEBUGP("Found checksum %lX vs module %lX\n",
935 *crc, versions[i].crc);
936 goto bad_version;
937 }
938
939 printk(KERN_WARNING "%s: no symbol version for %s\n",
940 mod->name, symname);
941 return 0;
942
943 bad_version:
944 printk("%s: disagrees about version of symbol %s\n",
945 mod->name, symname);
946 return 0;
947 }
948
949 static inline int check_modstruct_version(Elf_Shdr *sechdrs,
950 unsigned int versindex,
951 struct module *mod)
952 {
953 const unsigned long *crc;
954
955 if (IS_ERR_VALUE(find_symbol("struct_module", NULL, &crc, true, false)))
956 BUG();
957 return check_version(sechdrs, versindex, "struct_module", mod, crc);
958 }
959
960 /* First part is kernel version, which we ignore if module has crcs. */
961 static inline int same_magic(const char *amagic, const char *bmagic,
962 bool has_crcs)
963 {
964 if (has_crcs) {
965 amagic += strcspn(amagic, " ");
966 bmagic += strcspn(bmagic, " ");
967 }
968 return strcmp(amagic, bmagic) == 0;
969 }
970 #else
971 static inline int check_version(Elf_Shdr *sechdrs,
972 unsigned int versindex,
973 const char *symname,
974 struct module *mod,
975 const unsigned long *crc)
976 {
977 return 1;
978 }
979
980 static inline int check_modstruct_version(Elf_Shdr *sechdrs,
981 unsigned int versindex,
982 struct module *mod)
983 {
984 return 1;
985 }
986
987 static inline int same_magic(const char *amagic, const char *bmagic,
988 bool has_crcs)
989 {
990 return strcmp(amagic, bmagic) == 0;
991 }
992 #endif /* CONFIG_MODVERSIONS */
993
994 /* Resolve a symbol for this module. I.e. if we find one, record usage.
995 Must be holding module_mutex. */
996 static unsigned long resolve_symbol(Elf_Shdr *sechdrs,
997 unsigned int versindex,
998 const char *name,
999 struct module *mod)
1000 {
1001 struct module *owner;
1002 unsigned long ret;
1003 const unsigned long *crc;
1004
1005 ret = find_symbol(name, &owner, &crc,
1006 !(mod->taints & TAINT_PROPRIETARY_MODULE), true);
1007 if (!IS_ERR_VALUE(ret)) {
1008 /* use_module can fail due to OOM,
1009 or module initialization or unloading */
1010 if (!check_version(sechdrs, versindex, name, mod, crc) ||
1011 !use_module(mod, owner))
1012 ret = -EINVAL;
1013 }
1014 return ret;
1015 }
1016
1017 /*
1018 * /sys/module/foo/sections stuff
1019 * J. Corbet <corbet@lwn.net>
1020 */
1021 #if defined(CONFIG_KALLSYMS) && defined(CONFIG_SYSFS)
1022 struct module_sect_attr
1023 {
1024 struct module_attribute mattr;
1025 char *name;
1026 unsigned long address;
1027 };
1028
1029 struct module_sect_attrs
1030 {
1031 struct attribute_group grp;
1032 unsigned int nsections;
1033 struct module_sect_attr attrs[0];
1034 };
1035
1036 static ssize_t module_sect_show(struct module_attribute *mattr,
1037 struct module *mod, char *buf)
1038 {
1039 struct module_sect_attr *sattr =
1040 container_of(mattr, struct module_sect_attr, mattr);
1041 return sprintf(buf, "0x%lx\n", sattr->address);
1042 }
1043
1044 static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
1045 {
1046 unsigned int section;
1047
1048 for (section = 0; section < sect_attrs->nsections; section++)
1049 kfree(sect_attrs->attrs[section].name);
1050 kfree(sect_attrs);
1051 }
1052
1053 static void add_sect_attrs(struct module *mod, unsigned int nsect,
1054 char *secstrings, Elf_Shdr *sechdrs)
1055 {
1056 unsigned int nloaded = 0, i, size[2];
1057 struct module_sect_attrs *sect_attrs;
1058 struct module_sect_attr *sattr;
1059 struct attribute **gattr;
1060
1061 /* Count loaded sections and allocate structures */
1062 for (i = 0; i < nsect; i++)
1063 if (sechdrs[i].sh_flags & SHF_ALLOC)
1064 nloaded++;
1065 size[0] = ALIGN(sizeof(*sect_attrs)
1066 + nloaded * sizeof(sect_attrs->attrs[0]),
1067 sizeof(sect_attrs->grp.attrs[0]));
1068 size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]);
1069 sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
1070 if (sect_attrs == NULL)
1071 return;
1072
1073 /* Setup section attributes. */
1074 sect_attrs->grp.name = "sections";
1075 sect_attrs->grp.attrs = (void *)sect_attrs + size[0];
1076
1077 sect_attrs->nsections = 0;
1078 sattr = &sect_attrs->attrs[0];
1079 gattr = &sect_attrs->grp.attrs[0];
1080 for (i = 0; i < nsect; i++) {
1081 if (! (sechdrs[i].sh_flags & SHF_ALLOC))
1082 continue;
1083 sattr->address = sechdrs[i].sh_addr;
1084 sattr->name = kstrdup(secstrings + sechdrs[i].sh_name,
1085 GFP_KERNEL);
1086 if (sattr->name == NULL)
1087 goto out;
1088 sect_attrs->nsections++;
1089 sattr->mattr.show = module_sect_show;
1090 sattr->mattr.store = NULL;
1091 sattr->mattr.attr.name = sattr->name;
1092 sattr->mattr.attr.mode = S_IRUGO;
1093 *(gattr++) = &(sattr++)->mattr.attr;
1094 }
1095 *gattr = NULL;
1096
1097 if (sysfs_create_group(&mod->mkobj.kobj, &sect_attrs->grp))
1098 goto out;
1099
1100 mod->sect_attrs = sect_attrs;
1101 return;
1102 out:
1103 free_sect_attrs(sect_attrs);
1104 }
1105
1106 static void remove_sect_attrs(struct module *mod)
1107 {
1108 if (mod->sect_attrs) {
1109 sysfs_remove_group(&mod->mkobj.kobj,
1110 &mod->sect_attrs->grp);
1111 /* We are positive that no one is using any sect attrs
1112 * at this point. Deallocate immediately. */
1113 free_sect_attrs(mod->sect_attrs);
1114 mod->sect_attrs = NULL;
1115 }
1116 }
1117
1118 /*
1119 * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
1120 */
1121
1122 struct module_notes_attrs {
1123 struct kobject *dir;
1124 unsigned int notes;
1125 struct bin_attribute attrs[0];
1126 };
1127
1128 static ssize_t module_notes_read(struct kobject *kobj,
1129 struct bin_attribute *bin_attr,
1130 char *buf, loff_t pos, size_t count)
1131 {
1132 /*
1133 * The caller checked the pos and count against our size.
1134 */
1135 memcpy(buf, bin_attr->private + pos, count);
1136 return count;
1137 }
1138
1139 static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
1140 unsigned int i)
1141 {
1142 if (notes_attrs->dir) {
1143 while (i-- > 0)
1144 sysfs_remove_bin_file(notes_attrs->dir,
1145 &notes_attrs->attrs[i]);
1146 kobject_del(notes_attrs->dir);
1147 }
1148 kfree(notes_attrs);
1149 }
1150
1151 static void add_notes_attrs(struct module *mod, unsigned int nsect,
1152 char *secstrings, Elf_Shdr *sechdrs)
1153 {
1154 unsigned int notes, loaded, i;
1155 struct module_notes_attrs *notes_attrs;
1156 struct bin_attribute *nattr;
1157
1158 /* Count notes sections and allocate structures. */
1159 notes = 0;
1160 for (i = 0; i < nsect; i++)
1161 if ((sechdrs[i].sh_flags & SHF_ALLOC) &&
1162 (sechdrs[i].sh_type == SHT_NOTE))
1163 ++notes;
1164
1165 if (notes == 0)
1166 return;
1167
1168 notes_attrs = kzalloc(sizeof(*notes_attrs)
1169 + notes * sizeof(notes_attrs->attrs[0]),
1170 GFP_KERNEL);
1171 if (notes_attrs == NULL)
1172 return;
1173
1174 notes_attrs->notes = notes;
1175 nattr = &notes_attrs->attrs[0];
1176 for (loaded = i = 0; i < nsect; ++i) {
1177 if (!(sechdrs[i].sh_flags & SHF_ALLOC))
1178 continue;
1179 if (sechdrs[i].sh_type == SHT_NOTE) {
1180 nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
1181 nattr->attr.mode = S_IRUGO;
1182 nattr->size = sechdrs[i].sh_size;
1183 nattr->private = (void *) sechdrs[i].sh_addr;
1184 nattr->read = module_notes_read;
1185 ++nattr;
1186 }
1187 ++loaded;
1188 }
1189
1190 notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
1191 if (!notes_attrs->dir)
1192 goto out;
1193
1194 for (i = 0; i < notes; ++i)
1195 if (sysfs_create_bin_file(notes_attrs->dir,
1196 &notes_attrs->attrs[i]))
1197 goto out;
1198
1199 mod->notes_attrs = notes_attrs;
1200 return;
1201
1202 out:
1203 free_notes_attrs(notes_attrs, i);
1204 }
1205
1206 static void remove_notes_attrs(struct module *mod)
1207 {
1208 if (mod->notes_attrs)
1209 free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
1210 }
1211
1212 #else
1213
1214 static inline void add_sect_attrs(struct module *mod, unsigned int nsect,
1215 char *sectstrings, Elf_Shdr *sechdrs)
1216 {
1217 }
1218
1219 static inline void remove_sect_attrs(struct module *mod)
1220 {
1221 }
1222
1223 static inline void add_notes_attrs(struct module *mod, unsigned int nsect,
1224 char *sectstrings, Elf_Shdr *sechdrs)
1225 {
1226 }
1227
1228 static inline void remove_notes_attrs(struct module *mod)
1229 {
1230 }
1231 #endif
1232
1233 #ifdef CONFIG_SYSFS
1234 int module_add_modinfo_attrs(struct module *mod)
1235 {
1236 struct module_attribute *attr;
1237 struct module_attribute *temp_attr;
1238 int error = 0;
1239 int i;
1240
1241 mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
1242 (ARRAY_SIZE(modinfo_attrs) + 1)),
1243 GFP_KERNEL);
1244 if (!mod->modinfo_attrs)
1245 return -ENOMEM;
1246
1247 temp_attr = mod->modinfo_attrs;
1248 for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
1249 if (!attr->test ||
1250 (attr->test && attr->test(mod))) {
1251 memcpy(temp_attr, attr, sizeof(*temp_attr));
1252 error = sysfs_create_file(&mod->mkobj.kobj,&temp_attr->attr);
1253 ++temp_attr;
1254 }
1255 }
1256 return error;
1257 }
1258
1259 void module_remove_modinfo_attrs(struct module *mod)
1260 {
1261 struct module_attribute *attr;
1262 int i;
1263
1264 for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
1265 /* pick a field to test for end of list */
1266 if (!attr->attr.name)
1267 break;
1268 sysfs_remove_file(&mod->mkobj.kobj,&attr->attr);
1269 if (attr->free)
1270 attr->free(mod);
1271 }
1272 kfree(mod->modinfo_attrs);
1273 }
1274
1275 int mod_sysfs_init(struct module *mod)
1276 {
1277 int err;
1278 struct kobject *kobj;
1279
1280 if (!module_sysfs_initialized) {
1281 printk(KERN_ERR "%s: module sysfs not initialized\n",
1282 mod->name);
1283 err = -EINVAL;
1284 goto out;
1285 }
1286
1287 kobj = kset_find_obj(module_kset, mod->name);
1288 if (kobj) {
1289 printk(KERN_ERR "%s: module is already loaded\n", mod->name);
1290 kobject_put(kobj);
1291 err = -EINVAL;
1292 goto out;
1293 }
1294
1295 mod->mkobj.mod = mod;
1296
1297 memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
1298 mod->mkobj.kobj.kset = module_kset;
1299 err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
1300 "%s", mod->name);
1301 if (err)
1302 kobject_put(&mod->mkobj.kobj);
1303
1304 /* delay uevent until full sysfs population */
1305 out:
1306 return err;
1307 }
1308
1309 int mod_sysfs_setup(struct module *mod,
1310 struct kernel_param *kparam,
1311 unsigned int num_params)
1312 {
1313 int err;
1314
1315 mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1316 if (!mod->holders_dir) {
1317 err = -ENOMEM;
1318 goto out_unreg;
1319 }
1320
1321 err = module_param_sysfs_setup(mod, kparam, num_params);
1322 if (err)
1323 goto out_unreg_holders;
1324
1325 err = module_add_modinfo_attrs(mod);
1326 if (err)
1327 goto out_unreg_param;
1328
1329 kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
1330 return 0;
1331
1332 out_unreg_param:
1333 module_param_sysfs_remove(mod);
1334 out_unreg_holders:
1335 kobject_put(mod->holders_dir);
1336 out_unreg:
1337 kobject_put(&mod->mkobj.kobj);
1338 return err;
1339 }
1340 #endif
1341
1342 static void mod_kobject_remove(struct module *mod)
1343 {
1344 module_remove_modinfo_attrs(mod);
1345 module_param_sysfs_remove(mod);
1346 kobject_put(mod->mkobj.drivers_dir);
1347 kobject_put(mod->holders_dir);
1348 kobject_put(&mod->mkobj.kobj);
1349 }
1350
1351 /*
1352 * link the module with the whole machine is stopped with interrupts off
1353 * - this defends against kallsyms not taking locks
1354 */
1355 static int __link_module(void *_mod)
1356 {
1357 struct module *mod = _mod;
1358 list_add(&mod->list, &modules);
1359 return 0;
1360 }
1361
1362 /*
1363 * unlink the module with the whole machine is stopped with interrupts off
1364 * - this defends against kallsyms not taking locks
1365 */
1366 static int __unlink_module(void *_mod)
1367 {
1368 struct module *mod = _mod;
1369 list_del(&mod->list);
1370 return 0;
1371 }
1372
1373 /* Free a module, remove from lists, etc (must hold module_mutex). */
1374 static void free_module(struct module *mod)
1375 {
1376 /* Delete from various lists */
1377 stop_machine_run(__unlink_module, mod, NR_CPUS);
1378 remove_notes_attrs(mod);
1379 remove_sect_attrs(mod);
1380 mod_kobject_remove(mod);
1381
1382 unwind_remove_table(mod->unwind_info, 0);
1383
1384 /* Arch-specific cleanup. */
1385 module_arch_cleanup(mod);
1386
1387 /* Module unload stuff */
1388 module_unload_free(mod);
1389
1390 /* This may be NULL, but that's OK */
1391 module_free(mod, mod->module_init);
1392 kfree(mod->args);
1393 if (mod->percpu)
1394 percpu_modfree(mod->percpu);
1395
1396 /* Free lock-classes: */
1397 lockdep_free_key_range(mod->module_core, mod->core_size);
1398
1399 /* Finally, free the core (containing the module structure) */
1400 module_free(mod, mod->module_core);
1401 }
1402
1403 void *__symbol_get(const char *symbol)
1404 {
1405 struct module *owner;
1406 unsigned long value;
1407
1408 preempt_disable();
1409 value = find_symbol(symbol, &owner, NULL, true, true);
1410 if (IS_ERR_VALUE(value))
1411 value = 0;
1412 else if (strong_try_module_get(owner))
1413 value = 0;
1414 preempt_enable();
1415
1416 return (void *)value;
1417 }
1418 EXPORT_SYMBOL_GPL(__symbol_get);
1419
1420 /*
1421 * Ensure that an exported symbol [global namespace] does not already exist
1422 * in the kernel or in some other module's exported symbol table.
1423 */
1424 static int verify_export_symbols(struct module *mod)
1425 {
1426 unsigned int i;
1427 struct module *owner;
1428 const struct kernel_symbol *s;
1429 struct {
1430 const struct kernel_symbol *sym;
1431 unsigned int num;
1432 } arr[] = {
1433 { mod->syms, mod->num_syms },
1434 { mod->gpl_syms, mod->num_gpl_syms },
1435 { mod->gpl_future_syms, mod->num_gpl_future_syms },
1436 { mod->unused_syms, mod->num_unused_syms },
1437 { mod->unused_gpl_syms, mod->num_unused_gpl_syms },
1438 };
1439
1440 for (i = 0; i < ARRAY_SIZE(arr); i++) {
1441 for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
1442 if (!IS_ERR_VALUE(find_symbol(s->name, &owner,
1443 NULL, true, false))) {
1444 printk(KERN_ERR
1445 "%s: exports duplicate symbol %s"
1446 " (owned by %s)\n",
1447 mod->name, s->name, module_name(owner));
1448 return -ENOEXEC;
1449 }
1450 }
1451 }
1452 return 0;
1453 }
1454
1455 /* Change all symbols so that st_value encodes the pointer directly. */
1456 static int simplify_symbols(Elf_Shdr *sechdrs,
1457 unsigned int symindex,
1458 const char *strtab,
1459 unsigned int versindex,
1460 unsigned int pcpuindex,
1461 struct module *mod)
1462 {
1463 Elf_Sym *sym = (void *)sechdrs[symindex].sh_addr;
1464 unsigned long secbase;
1465 unsigned int i, n = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
1466 int ret = 0;
1467
1468 for (i = 1; i < n; i++) {
1469 switch (sym[i].st_shndx) {
1470 case SHN_COMMON:
1471 /* We compiled with -fno-common. These are not
1472 supposed to happen. */
1473 DEBUGP("Common symbol: %s\n", strtab + sym[i].st_name);
1474 printk("%s: please compile with -fno-common\n",
1475 mod->name);
1476 ret = -ENOEXEC;
1477 break;
1478
1479 case SHN_ABS:
1480 /* Don't need to do anything */
1481 DEBUGP("Absolute symbol: 0x%08lx\n",
1482 (long)sym[i].st_value);
1483 break;
1484
1485 case SHN_UNDEF:
1486 sym[i].st_value
1487 = resolve_symbol(sechdrs, versindex,
1488 strtab + sym[i].st_name, mod);
1489
1490 /* Ok if resolved. */
1491 if (!IS_ERR_VALUE(sym[i].st_value))
1492 break;
1493 /* Ok if weak. */
1494 if (ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
1495 break;
1496
1497 printk(KERN_WARNING "%s: Unknown symbol %s\n",
1498 mod->name, strtab + sym[i].st_name);
1499 ret = -ENOENT;
1500 break;
1501
1502 default:
1503 /* Divert to percpu allocation if a percpu var. */
1504 if (sym[i].st_shndx == pcpuindex)
1505 secbase = (unsigned long)mod->percpu;
1506 else
1507 secbase = sechdrs[sym[i].st_shndx].sh_addr;
1508 sym[i].st_value += secbase;
1509 break;
1510 }
1511 }
1512
1513 return ret;
1514 }
1515
1516 /* Update size with this section: return offset. */
1517 static long get_offset(unsigned long *size, Elf_Shdr *sechdr)
1518 {
1519 long ret;
1520
1521 ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
1522 *size = ret + sechdr->sh_size;
1523 return ret;
1524 }
1525
1526 /* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
1527 might -- code, read-only data, read-write data, small data. Tally
1528 sizes, and place the offsets into sh_entsize fields: high bit means it
1529 belongs in init. */
1530 static void layout_sections(struct module *mod,
1531 const Elf_Ehdr *hdr,
1532 Elf_Shdr *sechdrs,
1533 const char *secstrings)
1534 {
1535 static unsigned long const masks[][2] = {
1536 /* NOTE: all executable code must be the first section
1537 * in this array; otherwise modify the text_size
1538 * finder in the two loops below */
1539 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
1540 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
1541 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
1542 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
1543 };
1544 unsigned int m, i;
1545
1546 for (i = 0; i < hdr->e_shnum; i++)
1547 sechdrs[i].sh_entsize = ~0UL;
1548
1549 DEBUGP("Core section allocation order:\n");
1550 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
1551 for (i = 0; i < hdr->e_shnum; ++i) {
1552 Elf_Shdr *s = &sechdrs[i];
1553
1554 if ((s->sh_flags & masks[m][0]) != masks[m][0]
1555 || (s->sh_flags & masks[m][1])
1556 || s->sh_entsize != ~0UL
1557 || strncmp(secstrings + s->sh_name,
1558 ".init", 5) == 0)
1559 continue;
1560 s->sh_entsize = get_offset(&mod->core_size, s);
1561 DEBUGP("\t%s\n", secstrings + s->sh_name);
1562 }
1563 if (m == 0)
1564 mod->core_text_size = mod->core_size;
1565 }
1566
1567 DEBUGP("Init section allocation order:\n");
1568 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
1569 for (i = 0; i < hdr->e_shnum; ++i) {
1570 Elf_Shdr *s = &sechdrs[i];
1571
1572 if ((s->sh_flags & masks[m][0]) != masks[m][0]
1573 || (s->sh_flags & masks[m][1])
1574 || s->sh_entsize != ~0UL
1575 || strncmp(secstrings + s->sh_name,
1576 ".init", 5) != 0)
1577 continue;
1578 s->sh_entsize = (get_offset(&mod->init_size, s)
1579 | INIT_OFFSET_MASK);
1580 DEBUGP("\t%s\n", secstrings + s->sh_name);
1581 }
1582 if (m == 0)
1583 mod->init_text_size = mod->init_size;
1584 }
1585 }
1586
1587 static void set_license(struct module *mod, const char *license)
1588 {
1589 if (!license)
1590 license = "unspecified";
1591
1592 if (!license_is_gpl_compatible(license)) {
1593 if (!(tainted & TAINT_PROPRIETARY_MODULE))
1594 printk(KERN_WARNING "%s: module license '%s' taints "
1595 "kernel.\n", mod->name, license);
1596 add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
1597 }
1598 }
1599
1600 /* Parse tag=value strings from .modinfo section */
1601 static char *next_string(char *string, unsigned long *secsize)
1602 {
1603 /* Skip non-zero chars */
1604 while (string[0]) {
1605 string++;
1606 if ((*secsize)-- <= 1)
1607 return NULL;
1608 }
1609
1610 /* Skip any zero padding. */
1611 while (!string[0]) {
1612 string++;
1613 if ((*secsize)-- <= 1)
1614 return NULL;
1615 }
1616 return string;
1617 }
1618
1619 static char *get_modinfo(Elf_Shdr *sechdrs,
1620 unsigned int info,
1621 const char *tag)
1622 {
1623 char *p;
1624 unsigned int taglen = strlen(tag);
1625 unsigned long size = sechdrs[info].sh_size;
1626
1627 for (p = (char *)sechdrs[info].sh_addr; p; p = next_string(p, &size)) {
1628 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
1629 return p + taglen + 1;
1630 }
1631 return NULL;
1632 }
1633
1634 static void setup_modinfo(struct module *mod, Elf_Shdr *sechdrs,
1635 unsigned int infoindex)
1636 {
1637 struct module_attribute *attr;
1638 int i;
1639
1640 for (i = 0; (attr = modinfo_attrs[i]); i++) {
1641 if (attr->setup)
1642 attr->setup(mod,
1643 get_modinfo(sechdrs,
1644 infoindex,
1645 attr->attr.name));
1646 }
1647 }
1648
1649 #ifdef CONFIG_KALLSYMS
1650 static int is_exported(const char *name, const struct module *mod)
1651 {
1652 if (!mod && lookup_symbol(name, __start___ksymtab, __stop___ksymtab))
1653 return 1;
1654 else
1655 if (mod && lookup_symbol(name, mod->syms, mod->syms + mod->num_syms))
1656 return 1;
1657 else
1658 return 0;
1659 }
1660
1661 /* As per nm */
1662 static char elf_type(const Elf_Sym *sym,
1663 Elf_Shdr *sechdrs,
1664 const char *secstrings,
1665 struct module *mod)
1666 {
1667 if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
1668 if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
1669 return 'v';
1670 else
1671 return 'w';
1672 }
1673 if (sym->st_shndx == SHN_UNDEF)
1674 return 'U';
1675 if (sym->st_shndx == SHN_ABS)
1676 return 'a';
1677 if (sym->st_shndx >= SHN_LORESERVE)
1678 return '?';
1679 if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
1680 return 't';
1681 if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
1682 && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
1683 if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
1684 return 'r';
1685 else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
1686 return 'g';
1687 else
1688 return 'd';
1689 }
1690 if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
1691 if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
1692 return 's';
1693 else
1694 return 'b';
1695 }
1696 if (strncmp(secstrings + sechdrs[sym->st_shndx].sh_name,
1697 ".debug", strlen(".debug")) == 0)
1698 return 'n';
1699 return '?';
1700 }
1701
1702 static void add_kallsyms(struct module *mod,
1703 Elf_Shdr *sechdrs,
1704 unsigned int symindex,
1705 unsigned int strindex,
1706 const char *secstrings)
1707 {
1708 unsigned int i;
1709
1710 mod->symtab = (void *)sechdrs[symindex].sh_addr;
1711 mod->num_symtab = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
1712 mod->strtab = (void *)sechdrs[strindex].sh_addr;
1713
1714 /* Set types up while we still have access to sections. */
1715 for (i = 0; i < mod->num_symtab; i++)
1716 mod->symtab[i].st_info
1717 = elf_type(&mod->symtab[i], sechdrs, secstrings, mod);
1718 }
1719 #else
1720 static inline void add_kallsyms(struct module *mod,
1721 Elf_Shdr *sechdrs,
1722 unsigned int symindex,
1723 unsigned int strindex,
1724 const char *secstrings)
1725 {
1726 }
1727 #endif /* CONFIG_KALLSYMS */
1728
1729 /* Allocate and load the module: note that size of section 0 is always
1730 zero, and we rely on this for optional sections. */
1731 static struct module *load_module(void __user *umod,
1732 unsigned long len,
1733 const char __user *uargs)
1734 {
1735 Elf_Ehdr *hdr;
1736 Elf_Shdr *sechdrs;
1737 char *secstrings, *args, *modmagic, *strtab = NULL;
1738 unsigned int i;
1739 unsigned int symindex = 0;
1740 unsigned int strindex = 0;
1741 unsigned int setupindex;
1742 unsigned int exindex;
1743 unsigned int exportindex;
1744 unsigned int modindex;
1745 unsigned int obsparmindex;
1746 unsigned int infoindex;
1747 unsigned int gplindex;
1748 unsigned int crcindex;
1749 unsigned int gplcrcindex;
1750 unsigned int versindex;
1751 unsigned int pcpuindex;
1752 unsigned int gplfutureindex;
1753 unsigned int gplfuturecrcindex;
1754 unsigned int unwindex = 0;
1755 unsigned int unusedindex;
1756 unsigned int unusedcrcindex;
1757 unsigned int unusedgplindex;
1758 unsigned int unusedgplcrcindex;
1759 unsigned int markersindex;
1760 unsigned int markersstringsindex;
1761 struct module *mod;
1762 long err = 0;
1763 void *percpu = NULL, *ptr = NULL; /* Stops spurious gcc warning */
1764 struct exception_table_entry *extable;
1765 mm_segment_t old_fs;
1766
1767 DEBUGP("load_module: umod=%p, len=%lu, uargs=%p\n",
1768 umod, len, uargs);
1769 if (len < sizeof(*hdr))
1770 return ERR_PTR(-ENOEXEC);
1771
1772 /* Suck in entire file: we'll want most of it. */
1773 /* vmalloc barfs on "unusual" numbers. Check here */
1774 if (len > 64 * 1024 * 1024 || (hdr = vmalloc(len)) == NULL)
1775 return ERR_PTR(-ENOMEM);
1776 if (copy_from_user(hdr, umod, len) != 0) {
1777 err = -EFAULT;
1778 goto free_hdr;
1779 }
1780
1781 /* Sanity checks against insmoding binaries or wrong arch,
1782 weird elf version */
1783 if (memcmp(hdr->e_ident, ELFMAG, 4) != 0
1784 || hdr->e_type != ET_REL
1785 || !elf_check_arch(hdr)
1786 || hdr->e_shentsize != sizeof(*sechdrs)) {
1787 err = -ENOEXEC;
1788 goto free_hdr;
1789 }
1790
1791 if (len < hdr->e_shoff + hdr->e_shnum * sizeof(Elf_Shdr))
1792 goto truncated;
1793
1794 /* Convenience variables */
1795 sechdrs = (void *)hdr + hdr->e_shoff;
1796 secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
1797 sechdrs[0].sh_addr = 0;
1798
1799 for (i = 1; i < hdr->e_shnum; i++) {
1800 if (sechdrs[i].sh_type != SHT_NOBITS
1801 && len < sechdrs[i].sh_offset + sechdrs[i].sh_size)
1802 goto truncated;
1803
1804 /* Mark all sections sh_addr with their address in the
1805 temporary image. */
1806 sechdrs[i].sh_addr = (size_t)hdr + sechdrs[i].sh_offset;
1807
1808 /* Internal symbols and strings. */
1809 if (sechdrs[i].sh_type == SHT_SYMTAB) {
1810 symindex = i;
1811 strindex = sechdrs[i].sh_link;
1812 strtab = (char *)hdr + sechdrs[strindex].sh_offset;
1813 }
1814 #ifndef CONFIG_MODULE_UNLOAD
1815 /* Don't load .exit sections */
1816 if (strncmp(secstrings+sechdrs[i].sh_name, ".exit", 5) == 0)
1817 sechdrs[i].sh_flags &= ~(unsigned long)SHF_ALLOC;
1818 #endif
1819 }
1820
1821 modindex = find_sec(hdr, sechdrs, secstrings,
1822 ".gnu.linkonce.this_module");
1823 if (!modindex) {
1824 printk(KERN_WARNING "No module found in object\n");
1825 err = -ENOEXEC;
1826 goto free_hdr;
1827 }
1828 mod = (void *)sechdrs[modindex].sh_addr;
1829
1830 if (symindex == 0) {
1831 printk(KERN_WARNING "%s: module has no symbols (stripped?)\n",
1832 mod->name);
1833 err = -ENOEXEC;
1834 goto free_hdr;
1835 }
1836
1837 /* Optional sections */
1838 exportindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab");
1839 gplindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_gpl");
1840 gplfutureindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_gpl_future");
1841 unusedindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_unused");
1842 unusedgplindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_unused_gpl");
1843 crcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab");
1844 gplcrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_gpl");
1845 gplfuturecrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_gpl_future");
1846 unusedcrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_unused");
1847 unusedgplcrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_unused_gpl");
1848 setupindex = find_sec(hdr, sechdrs, secstrings, "__param");
1849 exindex = find_sec(hdr, sechdrs, secstrings, "__ex_table");
1850 obsparmindex = find_sec(hdr, sechdrs, secstrings, "__obsparm");
1851 versindex = find_sec(hdr, sechdrs, secstrings, "__versions");
1852 infoindex = find_sec(hdr, sechdrs, secstrings, ".modinfo");
1853 pcpuindex = find_pcpusec(hdr, sechdrs, secstrings);
1854 #ifdef ARCH_UNWIND_SECTION_NAME
1855 unwindex = find_sec(hdr, sechdrs, secstrings, ARCH_UNWIND_SECTION_NAME);
1856 #endif
1857
1858 /* Don't keep modinfo and version sections. */
1859 sechdrs[infoindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
1860 sechdrs[versindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
1861 #ifdef CONFIG_KALLSYMS
1862 /* Keep symbol and string tables for decoding later. */
1863 sechdrs[symindex].sh_flags |= SHF_ALLOC;
1864 sechdrs[strindex].sh_flags |= SHF_ALLOC;
1865 #endif
1866 if (unwindex)
1867 sechdrs[unwindex].sh_flags |= SHF_ALLOC;
1868
1869 /* Check module struct version now, before we try to use module. */
1870 if (!check_modstruct_version(sechdrs, versindex, mod)) {
1871 err = -ENOEXEC;
1872 goto free_hdr;
1873 }
1874
1875 modmagic = get_modinfo(sechdrs, infoindex, "vermagic");
1876 /* This is allowed: modprobe --force will invalidate it. */
1877 if (!modmagic) {
1878 err = try_to_force_load(mod, "magic");
1879 if (err)
1880 goto free_hdr;
1881 } else if (!same_magic(modmagic, vermagic, versindex)) {
1882 printk(KERN_ERR "%s: version magic '%s' should be '%s'\n",
1883 mod->name, modmagic, vermagic);
1884 err = -ENOEXEC;
1885 goto free_hdr;
1886 }
1887
1888 /* Now copy in args */
1889 args = strndup_user(uargs, ~0UL >> 1);
1890 if (IS_ERR(args)) {
1891 err = PTR_ERR(args);
1892 goto free_hdr;
1893 }
1894
1895 if (find_module(mod->name)) {
1896 err = -EEXIST;
1897 goto free_mod;
1898 }
1899
1900 mod->state = MODULE_STATE_COMING;
1901
1902 /* Allow arches to frob section contents and sizes. */
1903 err = module_frob_arch_sections(hdr, sechdrs, secstrings, mod);
1904 if (err < 0)
1905 goto free_mod;
1906
1907 if (pcpuindex) {
1908 /* We have a special allocation for this section. */
1909 percpu = percpu_modalloc(sechdrs[pcpuindex].sh_size,
1910 sechdrs[pcpuindex].sh_addralign,
1911 mod->name);
1912 if (!percpu) {
1913 err = -ENOMEM;
1914 goto free_mod;
1915 }
1916 sechdrs[pcpuindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
1917 mod->percpu = percpu;
1918 }
1919
1920 /* Determine total sizes, and put offsets in sh_entsize. For now
1921 this is done generically; there doesn't appear to be any
1922 special cases for the architectures. */
1923 layout_sections(mod, hdr, sechdrs, secstrings);
1924
1925 /* Do the allocs. */
1926 ptr = module_alloc(mod->core_size);
1927 if (!ptr) {
1928 err = -ENOMEM;
1929 goto free_percpu;
1930 }
1931 memset(ptr, 0, mod->core_size);
1932 mod->module_core = ptr;
1933
1934 ptr = module_alloc(mod->init_size);
1935 if (!ptr && mod->init_size) {
1936 err = -ENOMEM;
1937 goto free_core;
1938 }
1939 memset(ptr, 0, mod->init_size);
1940 mod->module_init = ptr;
1941
1942 /* Transfer each section which specifies SHF_ALLOC */
1943 DEBUGP("final section addresses:\n");
1944 for (i = 0; i < hdr->e_shnum; i++) {
1945 void *dest;
1946
1947 if (!(sechdrs[i].sh_flags & SHF_ALLOC))
1948 continue;
1949
1950 if (sechdrs[i].sh_entsize & INIT_OFFSET_MASK)
1951 dest = mod->module_init
1952 + (sechdrs[i].sh_entsize & ~INIT_OFFSET_MASK);
1953 else
1954 dest = mod->module_core + sechdrs[i].sh_entsize;
1955
1956 if (sechdrs[i].sh_type != SHT_NOBITS)
1957 memcpy(dest, (void *)sechdrs[i].sh_addr,
1958 sechdrs[i].sh_size);
1959 /* Update sh_addr to point to copy in image. */
1960 sechdrs[i].sh_addr = (unsigned long)dest;
1961 DEBUGP("\t0x%lx %s\n", sechdrs[i].sh_addr, secstrings + sechdrs[i].sh_name);
1962 }
1963 /* Module has been moved. */
1964 mod = (void *)sechdrs[modindex].sh_addr;
1965
1966 /* Now we've moved module, initialize linked lists, etc. */
1967 module_unload_init(mod);
1968
1969 /* add kobject, so we can reference it. */
1970 err = mod_sysfs_init(mod);
1971 if (err)
1972 goto free_unload;
1973
1974 /* Set up license info based on the info section */
1975 set_license(mod, get_modinfo(sechdrs, infoindex, "license"));
1976
1977 /*
1978 * ndiswrapper is under GPL by itself, but loads proprietary modules.
1979 * Don't use add_taint_module(), as it would prevent ndiswrapper from
1980 * using GPL-only symbols it needs.
1981 */
1982 if (strcmp(mod->name, "ndiswrapper") == 0)
1983 add_taint(TAINT_PROPRIETARY_MODULE);
1984
1985 /* driverloader was caught wrongly pretending to be under GPL */
1986 if (strcmp(mod->name, "driverloader") == 0)
1987 add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
1988
1989 /* Set up MODINFO_ATTR fields */
1990 setup_modinfo(mod, sechdrs, infoindex);
1991
1992 /* Fix up syms, so that st_value is a pointer to location. */
1993 err = simplify_symbols(sechdrs, symindex, strtab, versindex, pcpuindex,
1994 mod);
1995 if (err < 0)
1996 goto cleanup;
1997
1998 /* Set up EXPORTed & EXPORT_GPLed symbols (section 0 is 0 length) */
1999 mod->num_syms = sechdrs[exportindex].sh_size / sizeof(*mod->syms);
2000 mod->syms = (void *)sechdrs[exportindex].sh_addr;
2001 if (crcindex)
2002 mod->crcs = (void *)sechdrs[crcindex].sh_addr;
2003 mod->num_gpl_syms = sechdrs[gplindex].sh_size / sizeof(*mod->gpl_syms);
2004 mod->gpl_syms = (void *)sechdrs[gplindex].sh_addr;
2005 if (gplcrcindex)
2006 mod->gpl_crcs = (void *)sechdrs[gplcrcindex].sh_addr;
2007 mod->num_gpl_future_syms = sechdrs[gplfutureindex].sh_size /
2008 sizeof(*mod->gpl_future_syms);
2009 mod->num_unused_syms = sechdrs[unusedindex].sh_size /
2010 sizeof(*mod->unused_syms);
2011 mod->num_unused_gpl_syms = sechdrs[unusedgplindex].sh_size /
2012 sizeof(*mod->unused_gpl_syms);
2013 mod->gpl_future_syms = (void *)sechdrs[gplfutureindex].sh_addr;
2014 if (gplfuturecrcindex)
2015 mod->gpl_future_crcs = (void *)sechdrs[gplfuturecrcindex].sh_addr;
2016
2017 mod->unused_syms = (void *)sechdrs[unusedindex].sh_addr;
2018 if (unusedcrcindex)
2019 mod->unused_crcs = (void *)sechdrs[unusedcrcindex].sh_addr;
2020 mod->unused_gpl_syms = (void *)sechdrs[unusedgplindex].sh_addr;
2021 if (unusedgplcrcindex)
2022 mod->unused_gpl_crcs
2023 = (void *)sechdrs[unusedgplcrcindex].sh_addr;
2024
2025 #ifdef CONFIG_MODVERSIONS
2026 if ((mod->num_syms && !crcindex) ||
2027 (mod->num_gpl_syms && !gplcrcindex) ||
2028 (mod->num_gpl_future_syms && !gplfuturecrcindex) ||
2029 (mod->num_unused_syms && !unusedcrcindex) ||
2030 (mod->num_unused_gpl_syms && !unusedgplcrcindex)) {
2031 printk(KERN_WARNING "%s: No versions for exported symbols.\n", mod->name);
2032 err = try_to_force_load(mod, "nocrc");
2033 if (err)
2034 goto cleanup;
2035 }
2036 #endif
2037 markersindex = find_sec(hdr, sechdrs, secstrings, "__markers");
2038 markersstringsindex = find_sec(hdr, sechdrs, secstrings,
2039 "__markers_strings");
2040
2041 /* Now do relocations. */
2042 for (i = 1; i < hdr->e_shnum; i++) {
2043 const char *strtab = (char *)sechdrs[strindex].sh_addr;
2044 unsigned int info = sechdrs[i].sh_info;
2045
2046 /* Not a valid relocation section? */
2047 if (info >= hdr->e_shnum)
2048 continue;
2049
2050 /* Don't bother with non-allocated sections */
2051 if (!(sechdrs[info].sh_flags & SHF_ALLOC))
2052 continue;
2053
2054 if (sechdrs[i].sh_type == SHT_REL)
2055 err = apply_relocate(sechdrs, strtab, symindex, i,mod);
2056 else if (sechdrs[i].sh_type == SHT_RELA)
2057 err = apply_relocate_add(sechdrs, strtab, symindex, i,
2058 mod);
2059 if (err < 0)
2060 goto cleanup;
2061 }
2062 #ifdef CONFIG_MARKERS
2063 mod->markers = (void *)sechdrs[markersindex].sh_addr;
2064 mod->num_markers =
2065 sechdrs[markersindex].sh_size / sizeof(*mod->markers);
2066 #endif
2067
2068 /* Find duplicate symbols */
2069 err = verify_export_symbols(mod);
2070
2071 if (err < 0)
2072 goto cleanup;
2073
2074 /* Set up and sort exception table */
2075 mod->num_exentries = sechdrs[exindex].sh_size / sizeof(*mod->extable);
2076 mod->extable = extable = (void *)sechdrs[exindex].sh_addr;
2077 sort_extable(extable, extable + mod->num_exentries);
2078
2079 /* Finally, copy percpu area over. */
2080 percpu_modcopy(mod->percpu, (void *)sechdrs[pcpuindex].sh_addr,
2081 sechdrs[pcpuindex].sh_size);
2082
2083 add_kallsyms(mod, sechdrs, symindex, strindex, secstrings);
2084
2085 #ifdef CONFIG_MARKERS
2086 if (!mod->taints)
2087 marker_update_probe_range(mod->markers,
2088 mod->markers + mod->num_markers);
2089 #endif
2090 err = module_finalize(hdr, sechdrs, mod);
2091 if (err < 0)
2092 goto cleanup;
2093
2094 /* flush the icache in correct context */
2095 old_fs = get_fs();
2096 set_fs(KERNEL_DS);
2097
2098 /*
2099 * Flush the instruction cache, since we've played with text.
2100 * Do it before processing of module parameters, so the module
2101 * can provide parameter accessor functions of its own.
2102 */
2103 if (mod->module_init)
2104 flush_icache_range((unsigned long)mod->module_init,
2105 (unsigned long)mod->module_init
2106 + mod->init_size);
2107 flush_icache_range((unsigned long)mod->module_core,
2108 (unsigned long)mod->module_core + mod->core_size);
2109
2110 set_fs(old_fs);
2111
2112 mod->args = args;
2113 if (obsparmindex)
2114 printk(KERN_WARNING "%s: Ignoring obsolete parameters\n",
2115 mod->name);
2116
2117 /* Now sew it into the lists so we can get lockdep and oops
2118 * info during argument parsing. Noone should access us, since
2119 * strong_try_module_get() will fail. */
2120 stop_machine_run(__link_module, mod, NR_CPUS);
2121
2122 /* Size of section 0 is 0, so this works well if no params */
2123 err = parse_args(mod->name, mod->args,
2124 (struct kernel_param *)
2125 sechdrs[setupindex].sh_addr,
2126 sechdrs[setupindex].sh_size
2127 / sizeof(struct kernel_param),
2128 NULL);
2129 if (err < 0)
2130 goto unlink;
2131
2132 err = mod_sysfs_setup(mod,
2133 (struct kernel_param *)
2134 sechdrs[setupindex].sh_addr,
2135 sechdrs[setupindex].sh_size
2136 / sizeof(struct kernel_param));
2137 if (err < 0)
2138 goto unlink;
2139 add_sect_attrs(mod, hdr->e_shnum, secstrings, sechdrs);
2140 add_notes_attrs(mod, hdr->e_shnum, secstrings, sechdrs);
2141
2142 /* Size of section 0 is 0, so this works well if no unwind info. */
2143 mod->unwind_info = unwind_add_table(mod,
2144 (void *)sechdrs[unwindex].sh_addr,
2145 sechdrs[unwindex].sh_size);
2146
2147 /* Get rid of temporary copy */
2148 vfree(hdr);
2149
2150 /* Done! */
2151 return mod;
2152
2153 unlink:
2154 stop_machine_run(__unlink_module, mod, NR_CPUS);
2155 module_arch_cleanup(mod);
2156 cleanup:
2157 kobject_del(&mod->mkobj.kobj);
2158 kobject_put(&mod->mkobj.kobj);
2159 free_unload:
2160 module_unload_free(mod);
2161 module_free(mod, mod->module_init);
2162 free_core:
2163 module_free(mod, mod->module_core);
2164 free_percpu:
2165 if (percpu)
2166 percpu_modfree(percpu);
2167 free_mod:
2168 kfree(args);
2169 free_hdr:
2170 vfree(hdr);
2171 return ERR_PTR(err);
2172
2173 truncated:
2174 printk(KERN_ERR "Module len %lu truncated\n", len);
2175 err = -ENOEXEC;
2176 goto free_hdr;
2177 }
2178
2179 /* This is where the real work happens */
2180 asmlinkage long
2181 sys_init_module(void __user *umod,
2182 unsigned long len,
2183 const char __user *uargs)
2184 {
2185 struct module *mod;
2186 int ret = 0;
2187
2188 /* Must have permission */
2189 if (!capable(CAP_SYS_MODULE))
2190 return -EPERM;
2191
2192 /* Only one module load at a time, please */
2193 if (mutex_lock_interruptible(&module_mutex) != 0)
2194 return -EINTR;
2195
2196 /* Do all the hard work */
2197 mod = load_module(umod, len, uargs);
2198 if (IS_ERR(mod)) {
2199 mutex_unlock(&module_mutex);
2200 return PTR_ERR(mod);
2201 }
2202
2203 /* Drop lock so they can recurse */
2204 mutex_unlock(&module_mutex);
2205
2206 blocking_notifier_call_chain(&module_notify_list,
2207 MODULE_STATE_COMING, mod);
2208
2209 /* Start the module */
2210 if (mod->init != NULL)
2211 ret = mod->init();
2212 if (ret < 0) {
2213 /* Init routine failed: abort. Try to protect us from
2214 buggy refcounters. */
2215 mod->state = MODULE_STATE_GOING;
2216 synchronize_sched();
2217 module_put(mod);
2218 blocking_notifier_call_chain(&module_notify_list,
2219 MODULE_STATE_GOING, mod);
2220 mutex_lock(&module_mutex);
2221 free_module(mod);
2222 mutex_unlock(&module_mutex);
2223 wake_up(&module_wq);
2224 return ret;
2225 }
2226 if (ret > 0) {
2227 printk(KERN_WARNING "%s: '%s'->init suspiciously returned %d, "
2228 "it should follow 0/-E convention\n"
2229 KERN_WARNING "%s: loading module anyway...\n",
2230 __func__, mod->name, ret,
2231 __func__);
2232 dump_stack();
2233 }
2234
2235 /* Now it's a first class citizen! Wake up anyone waiting for it. */
2236 mod->state = MODULE_STATE_LIVE;
2237 wake_up(&module_wq);
2238
2239 mutex_lock(&module_mutex);
2240 /* Drop initial reference. */
2241 module_put(mod);
2242 unwind_remove_table(mod->unwind_info, 1);
2243 module_free(mod, mod->module_init);
2244 mod->module_init = NULL;
2245 mod->init_size = 0;
2246 mod->init_text_size = 0;
2247 mutex_unlock(&module_mutex);
2248
2249 return 0;
2250 }
2251
2252 static inline int within(unsigned long addr, void *start, unsigned long size)
2253 {
2254 return ((void *)addr >= start && (void *)addr < start + size);
2255 }
2256
2257 #ifdef CONFIG_KALLSYMS
2258 /*
2259 * This ignores the intensely annoying "mapping symbols" found
2260 * in ARM ELF files: $a, $t and $d.
2261 */
2262 static inline int is_arm_mapping_symbol(const char *str)
2263 {
2264 return str[0] == '$' && strchr("atd", str[1])
2265 && (str[2] == '\0' || str[2] == '.');
2266 }
2267
2268 static const char *get_ksymbol(struct module *mod,
2269 unsigned long addr,
2270 unsigned long *size,
2271 unsigned long *offset)
2272 {
2273 unsigned int i, best = 0;
2274 unsigned long nextval;
2275
2276 /* At worse, next value is at end of module */
2277 if (within(addr, mod->module_init, mod->init_size))
2278 nextval = (unsigned long)mod->module_init+mod->init_text_size;
2279 else
2280 nextval = (unsigned long)mod->module_core+mod->core_text_size;
2281
2282 /* Scan for closest preceeding symbol, and next symbol. (ELF
2283 starts real symbols at 1). */
2284 for (i = 1; i < mod->num_symtab; i++) {
2285 if (mod->symtab[i].st_shndx == SHN_UNDEF)
2286 continue;
2287
2288 /* We ignore unnamed symbols: they're uninformative
2289 * and inserted at a whim. */
2290 if (mod->symtab[i].st_value <= addr
2291 && mod->symtab[i].st_value > mod->symtab[best].st_value
2292 && *(mod->strtab + mod->symtab[i].st_name) != '\0'
2293 && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
2294 best = i;
2295 if (mod->symtab[i].st_value > addr
2296 && mod->symtab[i].st_value < nextval
2297 && *(mod->strtab + mod->symtab[i].st_name) != '\0'
2298 && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
2299 nextval = mod->symtab[i].st_value;
2300 }
2301
2302 if (!best)
2303 return NULL;
2304
2305 if (size)
2306 *size = nextval - mod->symtab[best].st_value;
2307 if (offset)
2308 *offset = addr - mod->symtab[best].st_value;
2309 return mod->strtab + mod->symtab[best].st_name;
2310 }
2311
2312 /* For kallsyms to ask for address resolution. NULL means not found. Careful
2313 * not to lock to avoid deadlock on oopses, simply disable preemption. */
2314 const char *module_address_lookup(unsigned long addr,
2315 unsigned long *size,
2316 unsigned long *offset,
2317 char **modname,
2318 char *namebuf)
2319 {
2320 struct module *mod;
2321 const char *ret = NULL;
2322
2323 preempt_disable();
2324 list_for_each_entry(mod, &modules, list) {
2325 if (within(addr, mod->module_init, mod->init_size)
2326 || within(addr, mod->module_core, mod->core_size)) {
2327 if (modname)
2328 *modname = mod->name;
2329 ret = get_ksymbol(mod, addr, size, offset);
2330 break;
2331 }
2332 }
2333 /* Make a copy in here where it's safe */
2334 if (ret) {
2335 strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
2336 ret = namebuf;
2337 }
2338 preempt_enable();
2339 return ret;
2340 }
2341
2342 int lookup_module_symbol_name(unsigned long addr, char *symname)
2343 {
2344 struct module *mod;
2345
2346 preempt_disable();
2347 list_for_each_entry(mod, &modules, list) {
2348 if (within(addr, mod->module_init, mod->init_size) ||
2349 within(addr, mod->module_core, mod->core_size)) {
2350 const char *sym;
2351
2352 sym = get_ksymbol(mod, addr, NULL, NULL);
2353 if (!sym)
2354 goto out;
2355 strlcpy(symname, sym, KSYM_NAME_LEN);
2356 preempt_enable();
2357 return 0;
2358 }
2359 }
2360 out:
2361 preempt_enable();
2362 return -ERANGE;
2363 }
2364
2365 int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
2366 unsigned long *offset, char *modname, char *name)
2367 {
2368 struct module *mod;
2369
2370 preempt_disable();
2371 list_for_each_entry(mod, &modules, list) {
2372 if (within(addr, mod->module_init, mod->init_size) ||
2373 within(addr, mod->module_core, mod->core_size)) {
2374 const char *sym;
2375
2376 sym = get_ksymbol(mod, addr, size, offset);
2377 if (!sym)
2378 goto out;
2379 if (modname)
2380 strlcpy(modname, mod->name, MODULE_NAME_LEN);
2381 if (name)
2382 strlcpy(name, sym, KSYM_NAME_LEN);
2383 preempt_enable();
2384 return 0;
2385 }
2386 }
2387 out:
2388 preempt_enable();
2389 return -ERANGE;
2390 }
2391
2392 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
2393 char *name, char *module_name, int *exported)
2394 {
2395 struct module *mod;
2396
2397 preempt_disable();
2398 list_for_each_entry(mod, &modules, list) {
2399 if (symnum < mod->num_symtab) {
2400 *value = mod->symtab[symnum].st_value;
2401 *type = mod->symtab[symnum].st_info;
2402 strlcpy(name, mod->strtab + mod->symtab[symnum].st_name,
2403 KSYM_NAME_LEN);
2404 strlcpy(module_name, mod->name, MODULE_NAME_LEN);
2405 *exported = is_exported(name, mod);
2406 preempt_enable();
2407 return 0;
2408 }
2409 symnum -= mod->num_symtab;
2410 }
2411 preempt_enable();
2412 return -ERANGE;
2413 }
2414
2415 static unsigned long mod_find_symname(struct module *mod, const char *name)
2416 {
2417 unsigned int i;
2418
2419 for (i = 0; i < mod->num_symtab; i++)
2420 if (strcmp(name, mod->strtab+mod->symtab[i].st_name) == 0 &&
2421 mod->symtab[i].st_info != 'U')
2422 return mod->symtab[i].st_value;
2423 return 0;
2424 }
2425
2426 /* Look for this name: can be of form module:name. */
2427 unsigned long module_kallsyms_lookup_name(const char *name)
2428 {
2429 struct module *mod;
2430 char *colon;
2431 unsigned long ret = 0;
2432
2433 /* Don't lock: we're in enough trouble already. */
2434 preempt_disable();
2435 if ((colon = strchr(name, ':')) != NULL) {
2436 *colon = '\0';
2437 if ((mod = find_module(name)) != NULL)
2438 ret = mod_find_symname(mod, colon+1);
2439 *colon = ':';
2440 } else {
2441 list_for_each_entry(mod, &modules, list)
2442 if ((ret = mod_find_symname(mod, name)) != 0)
2443 break;
2444 }
2445 preempt_enable();
2446 return ret;
2447 }
2448 #endif /* CONFIG_KALLSYMS */
2449
2450 /* Called by the /proc file system to return a list of modules. */
2451 static void *m_start(struct seq_file *m, loff_t *pos)
2452 {
2453 mutex_lock(&module_mutex);
2454 return seq_list_start(&modules, *pos);
2455 }
2456
2457 static void *m_next(struct seq_file *m, void *p, loff_t *pos)
2458 {
2459 return seq_list_next(p, &modules, pos);
2460 }
2461
2462 static void m_stop(struct seq_file *m, void *p)
2463 {
2464 mutex_unlock(&module_mutex);
2465 }
2466
2467 static char *module_flags(struct module *mod, char *buf)
2468 {
2469 int bx = 0;
2470
2471 if (mod->taints ||
2472 mod->state == MODULE_STATE_GOING ||
2473 mod->state == MODULE_STATE_COMING) {
2474 buf[bx++] = '(';
2475 if (mod->taints & TAINT_PROPRIETARY_MODULE)
2476 buf[bx++] = 'P';
2477 if (mod->taints & TAINT_FORCED_MODULE)
2478 buf[bx++] = 'F';
2479 /*
2480 * TAINT_FORCED_RMMOD: could be added.
2481 * TAINT_UNSAFE_SMP, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't
2482 * apply to modules.
2483 */
2484
2485 /* Show a - for module-is-being-unloaded */
2486 if (mod->state == MODULE_STATE_GOING)
2487 buf[bx++] = '-';
2488 /* Show a + for module-is-being-loaded */
2489 if (mod->state == MODULE_STATE_COMING)
2490 buf[bx++] = '+';
2491 buf[bx++] = ')';
2492 }
2493 buf[bx] = '\0';
2494
2495 return buf;
2496 }
2497
2498 static int m_show(struct seq_file *m, void *p)
2499 {
2500 struct module *mod = list_entry(p, struct module, list);
2501 char buf[8];
2502
2503 seq_printf(m, "%s %lu",
2504 mod->name, mod->init_size + mod->core_size);
2505 print_unload_info(m, mod);
2506
2507 /* Informative for users. */
2508 seq_printf(m, " %s",
2509 mod->state == MODULE_STATE_GOING ? "Unloading":
2510 mod->state == MODULE_STATE_COMING ? "Loading":
2511 "Live");
2512 /* Used by oprofile and other similar tools. */
2513 seq_printf(m, " 0x%p", mod->module_core);
2514
2515 /* Taints info */
2516 if (mod->taints)
2517 seq_printf(m, " %s", module_flags(mod, buf));
2518
2519 seq_printf(m, "\n");
2520 return 0;
2521 }
2522
2523 /* Format: modulename size refcount deps address
2524
2525 Where refcount is a number or -, and deps is a comma-separated list
2526 of depends or -.
2527 */
2528 const struct seq_operations modules_op = {
2529 .start = m_start,
2530 .next = m_next,
2531 .stop = m_stop,
2532 .show = m_show
2533 };
2534
2535 /* Given an address, look for it in the module exception tables. */
2536 const struct exception_table_entry *search_module_extables(unsigned long addr)
2537 {
2538 const struct exception_table_entry *e = NULL;
2539 struct module *mod;
2540
2541 preempt_disable();
2542 list_for_each_entry(mod, &modules, list) {
2543 if (mod->num_exentries == 0)
2544 continue;
2545
2546 e = search_extable(mod->extable,
2547 mod->extable + mod->num_exentries - 1,
2548 addr);
2549 if (e)
2550 break;
2551 }
2552 preempt_enable();
2553
2554 /* Now, if we found one, we are running inside it now, hence
2555 we cannot unload the module, hence no refcnt needed. */
2556 return e;
2557 }
2558
2559 /*
2560 * Is this a valid module address?
2561 */
2562 int is_module_address(unsigned long addr)
2563 {
2564 struct module *mod;
2565
2566 preempt_disable();
2567
2568 list_for_each_entry(mod, &modules, list) {
2569 if (within(addr, mod->module_core, mod->core_size)) {
2570 preempt_enable();
2571 return 1;
2572 }
2573 }
2574
2575 preempt_enable();
2576
2577 return 0;
2578 }
2579
2580
2581 /* Is this a valid kernel address? */
2582 struct module *__module_text_address(unsigned long addr)
2583 {
2584 struct module *mod;
2585
2586 list_for_each_entry(mod, &modules, list)
2587 if (within(addr, mod->module_init, mod->init_text_size)
2588 || within(addr, mod->module_core, mod->core_text_size))
2589 return mod;
2590 return NULL;
2591 }
2592
2593 struct module *module_text_address(unsigned long addr)
2594 {
2595 struct module *mod;
2596
2597 preempt_disable();
2598 mod = __module_text_address(addr);
2599 preempt_enable();
2600
2601 return mod;
2602 }
2603
2604 /* Don't grab lock, we're oopsing. */
2605 void print_modules(void)
2606 {
2607 struct module *mod;
2608 char buf[8];
2609
2610 printk("Modules linked in:");
2611 list_for_each_entry(mod, &modules, list)
2612 printk(" %s%s", mod->name, module_flags(mod, buf));
2613 if (last_unloaded_module[0])
2614 printk(" [last unloaded: %s]", last_unloaded_module);
2615 printk("\n");
2616 }
2617
2618 #ifdef CONFIG_MODVERSIONS
2619 /* Generate the signature for struct module here, too, for modversions. */
2620 void struct_module(struct module *mod) { return; }
2621 EXPORT_SYMBOL(struct_module);
2622 #endif
2623
2624 #ifdef CONFIG_MARKERS
2625 void module_update_markers(void)
2626 {
2627 struct module *mod;
2628
2629 mutex_lock(&module_mutex);
2630 list_for_each_entry(mod, &modules, list)
2631 if (!mod->taints)
2632 marker_update_probe_range(mod->markers,
2633 mod->markers + mod->num_markers);
2634 mutex_unlock(&module_mutex);
2635 }
2636 #endif
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