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[PATCH] lightweight robust futexes updates 2
[linux-2.6-block.git] / kernel / module.c
CommitLineData
1da177e4
LT		 1/* Rewritten by Rusty Russell, on the backs of many others...
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/config.h>
20#include <linux/module.h>
21#include <linux/moduleloader.h>
22#include <linux/init.h>
9f158333 23#include <linux/kernel.h>
1da177e4
LT		 24#include <linux/slab.h>
25#include <linux/vmalloc.h>
26#include <linux/elf.h>
27#include <linux/seq_file.h>
28#include <linux/syscalls.h>
29#include <linux/fcntl.h>
30#include <linux/rcupdate.h>
c59ede7b 31#include <linux/capability.h>
1da177e4
LT		 32#include <linux/cpu.h>
33#include <linux/moduleparam.h>
34#include <linux/errno.h>
35#include <linux/err.h>
36#include <linux/vermagic.h>
37#include <linux/notifier.h>
38#include <linux/stop_machine.h>
39#include <linux/device.h>
c988d2b2 40#include <linux/string.h>
8c65b4a6 41#include <linux/sched.h>
97d1f15b 42#include <linux/mutex.h>
1da177e4
LT		 43#include <asm/uaccess.h>
44#include <asm/semaphore.h>
45#include <asm/cacheflush.h>
46
47#if 0
48#define DEBUGP printk
49#else
50#define DEBUGP(fmt , a...)
51#endif
52
53#ifndef ARCH_SHF_SMALL
54#define ARCH_SHF_SMALL 0
55#endif
56
57/* If this is set, the section belongs in the init part of the module */
58#define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
59
60/* Protects module list */
61static DEFINE_SPINLOCK(modlist_lock);
62
63/* List of modules, protected by module_mutex AND modlist_lock */
6389a385 64static DEFINE_MUTEX(module_mutex);
1da177e4
LT		 65static LIST_HEAD(modules);
66
97d1f15b 67static DEFINE_MUTEX(notify_mutex);
1da177e4
LT		 68static struct notifier_block * module_notify_list;
69
70int register_module_notifier(struct notifier_block * nb)
71{
72 int err;
97d1f15b 73 mutex_lock(&notify_mutex);
1da177e4 74 err = notifier_chain_register(&module_notify_list, nb);
97d1f15b 75 mutex_unlock(&notify_mutex);
1da177e4
LT		 76 return err;
77}
78EXPORT_SYMBOL(register_module_notifier);
79
80int unregister_module_notifier(struct notifier_block * nb)
81{
82 int err;
97d1f15b 83 mutex_lock(&notify_mutex);
1da177e4 84 err = notifier_chain_unregister(&module_notify_list, nb);
97d1f15b 85 mutex_unlock(&notify_mutex);
1da177e4
LT		 86 return err;
87}
88EXPORT_SYMBOL(unregister_module_notifier);
89
90/* We require a truly strong try_module_get() */
91static inline int strong_try_module_get(struct module *mod)
92{
93 if (mod && mod->state == MODULE_STATE_COMING)
94 return 0;
95 return try_module_get(mod);
96}
97
98/* A thread that wants to hold a reference to a module only while it
99 * is running can call ths to safely exit.
100 * nfsd and lockd use this.
101 */
102void __module_put_and_exit(struct module *mod, long code)
103{
104 module_put(mod);
105 do_exit(code);
106}
107EXPORT_SYMBOL(__module_put_and_exit);
108
109/* Find a module section: 0 means not found. */
110static unsigned int find_sec(Elf_Ehdr *hdr,
111 Elf_Shdr *sechdrs,
112 const char *secstrings,
113 const char *name)
114{
115 unsigned int i;
116
117 for (i = 1; i < hdr->e_shnum; i++)
118 /* Alloc bit cleared means "ignore it." */
119 if ((sechdrs[i].sh_flags & SHF_ALLOC)
120 && strcmp(secstrings+sechdrs[i].sh_name, name) == 0)
121 return i;
122 return 0;
123}
124
125/* Provided by the linker */
126extern const struct kernel_symbol __start___ksymtab[];
127extern const struct kernel_symbol __stop___ksymtab[];
128extern const struct kernel_symbol __start___ksymtab_gpl[];
129extern const struct kernel_symbol __stop___ksymtab_gpl[];
9f28bb7e
GKH		 130extern const struct kernel_symbol __start___ksymtab_gpl_future[];
131extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
1da177e4
LT		 132extern const unsigned long __start___kcrctab[];
133extern const unsigned long __start___kcrctab_gpl[];
9f28bb7e 134extern const unsigned long __start___kcrctab_gpl_future[];
1da177e4
LT		 135
136#ifndef CONFIG_MODVERSIONS
137#define symversion(base, idx) NULL
138#else
139#define symversion(base, idx) ((base) ? ((base) + (idx)) : NULL)
140#endif
141
3fd6805f
SR		 142/* lookup symbol in given range of kernel_symbols */
143static const struct kernel_symbol *lookup_symbol(const char *name,
144 const struct kernel_symbol *start,
145 const struct kernel_symbol *stop)
146{
147 const struct kernel_symbol *ks = start;
148 for (; ks < stop; ks++)
149 if (strcmp(ks->name, name) == 0)
150 return ks;
151 return NULL;
152}
153
1da177e4
LT		 154/* Find a symbol, return value, crc and module which owns it */
155static unsigned long __find_symbol(const char *name,
156 struct module **owner,
157 const unsigned long **crc,
158 int gplok)
159{
160 struct module *mod;
3fd6805f 161 const struct kernel_symbol *ks;
1da177e4
LT		 162
163 /* Core kernel first. */
164 *owner = NULL;
3fd6805f
SR		 165 ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
166 if (ks) {
167 *crc = symversion(__start___kcrctab, (ks - __start___ksymtab));
168 return ks->value;
1da177e4
LT		 169 }
170 if (gplok) {
3fd6805f
SR		 171 ks = lookup_symbol(name, __start___ksymtab_gpl,
172 __stop___ksymtab_gpl);
173 if (ks) {
174 *crc = symversion(__start___kcrctab_gpl,
175 (ks - __start___ksymtab_gpl));
176 return ks->value;
177 }
1da177e4 178 }
9f28bb7e
GKH		 179 ks = lookup_symbol(name, __start___ksymtab_gpl_future,
180 __stop___ksymtab_gpl_future);
181 if (ks) {
182 if (!gplok) {
183 printk(KERN_WARNING "Symbol %s is being used "
184 "by a non-GPL module, which will not "
185 "be allowed in the future\n", name);
186 printk(KERN_WARNING "Please see the file "
187 "Documentation/feature-removal-schedule.txt "
188 "in the kernel source tree for more "
189 "details.\n");
190 }
191 *crc = symversion(__start___kcrctab_gpl_future,
192 (ks - __start___ksymtab_gpl_future));
193 return ks->value;
194 }
1da177e4
LT		 195
196 /* Now try modules. */
197 list_for_each_entry(mod, &modules, list) {
198 *owner = mod;
3fd6805f
SR		 199 ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
200 if (ks) {
201 *crc = symversion(mod->crcs, (ks - mod->syms));
202 return ks->value;
203 }
1da177e4
LT		 204
205 if (gplok) {
3fd6805f
SR		 206 ks = lookup_symbol(name, mod->gpl_syms,
207 mod->gpl_syms + mod->num_gpl_syms);
208 if (ks) {
209 *crc = symversion(mod->gpl_crcs,
210 (ks - mod->gpl_syms));
211 return ks->value;
1da177e4
LT		 212 }
213 }
9f28bb7e
GKH		 214 ks = lookup_symbol(name, mod->gpl_future_syms,
215 (mod->gpl_future_syms +
216 mod->num_gpl_future_syms));
217 if (ks) {
218 if (!gplok) {
219 printk(KERN_WARNING "Symbol %s is being used "
220 "by a non-GPL module, which will not "
221 "be allowed in the future\n", name);
222 printk(KERN_WARNING "Please see the file "
223 "Documentation/feature-removal-schedule.txt "
224 "in the kernel source tree for more "
225 "details.\n");
226 }
227 *crc = symversion(mod->gpl_future_crcs,
228 (ks - mod->gpl_future_syms));
229 return ks->value;
230 }
1da177e4
LT		 231 }
232 DEBUGP("Failed to find symbol %s\n", name);
233 return 0;
234}
235
1da177e4
LT		 236/* Search for module by name: must hold module_mutex. */
237static struct module *find_module(const char *name)
238{
239 struct module *mod;
240
241 list_for_each_entry(mod, &modules, list) {
242 if (strcmp(mod->name, name) == 0)
243 return mod;
244 }
245 return NULL;
246}
247
248#ifdef CONFIG_SMP
249/* Number of blocks used and allocated. */
250static unsigned int pcpu_num_used, pcpu_num_allocated;
251/* Size of each block. -ve means used. */
252static int *pcpu_size;
253
254static int split_block(unsigned int i, unsigned short size)
255{
256 /* Reallocation required? */
257 if (pcpu_num_used + 1 > pcpu_num_allocated) {
258 int *new = kmalloc(sizeof(new[0]) * pcpu_num_allocated*2,
259 GFP_KERNEL);
260 if (!new)
261 return 0;
262
263 memcpy(new, pcpu_size, sizeof(new[0])*pcpu_num_allocated);
264 pcpu_num_allocated *= 2;
265 kfree(pcpu_size);
266 pcpu_size = new;
267 }
268
269 /* Insert a new subblock */
270 memmove(&pcpu_size[i+1], &pcpu_size[i],
271 sizeof(pcpu_size[0]) * (pcpu_num_used - i));
272 pcpu_num_used++;
273
274 pcpu_size[i+1] -= size;
275 pcpu_size[i] = size;
276 return 1;
277}
278
279static inline unsigned int block_size(int val)
280{
281 if (val < 0)
282 return -val;
283 return val;
284}
285
286/* Created by linker magic */
287extern char __per_cpu_start[], __per_cpu_end[];
288
842bbaaa
RR		 289static void *percpu_modalloc(unsigned long size, unsigned long align,
290 const char *name)
1da177e4
LT		 291{
292 unsigned long extra;
293 unsigned int i;
294 void *ptr;
295
842bbaaa
RR		 296 if (align > SMP_CACHE_BYTES) {
297 printk(KERN_WARNING "%s: per-cpu alignment %li > %i\n",
298 name, align, SMP_CACHE_BYTES);
299 align = SMP_CACHE_BYTES;
300 }
1da177e4
LT		 301
302 ptr = __per_cpu_start;
303 for (i = 0; i < pcpu_num_used; ptr += block_size(pcpu_size[i]), i++) {
304 /* Extra for alignment requirement. */
305 extra = ALIGN((unsigned long)ptr, align) - (unsigned long)ptr;
306 BUG_ON(i == 0 && extra != 0);
307
308 if (pcpu_size[i] < 0 || pcpu_size[i] < extra + size)
309 continue;
310
311 /* Transfer extra to previous block. */
312 if (pcpu_size[i-1] < 0)
313 pcpu_size[i-1] -= extra;
314 else
315 pcpu_size[i-1] += extra;
316 pcpu_size[i] -= extra;
317 ptr += extra;
318
319 /* Split block if warranted */
320 if (pcpu_size[i] - size > sizeof(unsigned long))
321 if (!split_block(i, size))
322 return NULL;
323
324 /* Mark allocated */
325 pcpu_size[i] = -pcpu_size[i];
326 return ptr;
327 }
328
329 printk(KERN_WARNING "Could not allocate %lu bytes percpu data\n",
330 size);
331 return NULL;
332}
333
334static void percpu_modfree(void *freeme)
335{
336 unsigned int i;
337 void *ptr = __per_cpu_start + block_size(pcpu_size[0]);
338
339 /* First entry is core kernel percpu data. */
340 for (i = 1; i < pcpu_num_used; ptr += block_size(pcpu_size[i]), i++) {
341 if (ptr == freeme) {
342 pcpu_size[i] = -pcpu_size[i];
343 goto free;
344 }
345 }
346 BUG();
347
348 free:
349 /* Merge with previous? */
350 if (pcpu_size[i-1] >= 0) {
351 pcpu_size[i-1] += pcpu_size[i];
352 pcpu_num_used--;
353 memmove(&pcpu_size[i], &pcpu_size[i+1],
354 (pcpu_num_used - i) * sizeof(pcpu_size[0]));
355 i--;
356 }
357 /* Merge with next? */
358 if (i+1 < pcpu_num_used && pcpu_size[i+1] >= 0) {
359 pcpu_size[i] += pcpu_size[i+1];
360 pcpu_num_used--;
361 memmove(&pcpu_size[i+1], &pcpu_size[i+2],
362 (pcpu_num_used - (i+1)) * sizeof(pcpu_size[0]));
363 }
364}
365
366static unsigned int find_pcpusec(Elf_Ehdr *hdr,
367 Elf_Shdr *sechdrs,
368 const char *secstrings)
369{
370 return find_sec(hdr, sechdrs, secstrings, ".data.percpu");
371}
372
373static int percpu_modinit(void)
374{
375 pcpu_num_used = 2;
376 pcpu_num_allocated = 2;
377 pcpu_size = kmalloc(sizeof(pcpu_size[0]) * pcpu_num_allocated,
378 GFP_KERNEL);
379 /* Static in-kernel percpu data (used). */
380 pcpu_size[0] = -ALIGN(__per_cpu_end-__per_cpu_start, SMP_CACHE_BYTES);
381 /* Free room. */
382 pcpu_size[1] = PERCPU_ENOUGH_ROOM + pcpu_size[0];
383 if (pcpu_size[1] < 0) {
384 printk(KERN_ERR "No per-cpu room for modules.\n");
385 pcpu_num_used = 1;
386 }
387
388 return 0;
389}
390__initcall(percpu_modinit);
391#else /* ... !CONFIG_SMP */
842bbaaa
RR		 392static inline void *percpu_modalloc(unsigned long size, unsigned long align,
393 const char *name)
1da177e4
LT		 394{
395 return NULL;
396}
397static inline void percpu_modfree(void *pcpuptr)
398{
399 BUG();
400}
401static inline unsigned int find_pcpusec(Elf_Ehdr *hdr,
402 Elf_Shdr *sechdrs,
403 const char *secstrings)
404{
405 return 0;
406}
407static inline void percpu_modcopy(void *pcpudst, const void *src,
408 unsigned long size)
409{
410 /* pcpusec should be 0, and size of that section should be 0. */
411 BUG_ON(size != 0);
412}
413#endif /* CONFIG_SMP */
414
c988d2b2
MD		 415#define MODINFO_ATTR(field) \
416static void setup_modinfo_##field(struct module *mod, const char *s) \
417{ \
418 mod->field = kstrdup(s, GFP_KERNEL); \
419} \
420static ssize_t show_modinfo_##field(struct module_attribute *mattr, \
421 struct module *mod, char *buffer) \
422{ \
423 return sprintf(buffer, "%s\n", mod->field); \
424} \
425static int modinfo_##field##_exists(struct module *mod) \
426{ \
427 return mod->field != NULL; \
428} \
429static void free_modinfo_##field(struct module *mod) \
430{ \
431 kfree(mod->field); \
432 mod->field = NULL; \
433} \
434static struct module_attribute modinfo_##field = { \
435 .attr = { .name = __stringify(field), .mode = 0444, \
436 .owner = THIS_MODULE }, \
437 .show = show_modinfo_##field, \
438 .setup = setup_modinfo_##field, \
439 .test = modinfo_##field##_exists, \
440 .free = free_modinfo_##field, \
441};
442
443MODINFO_ATTR(version);
444MODINFO_ATTR(srcversion);
445
03e88ae1 446#ifdef CONFIG_MODULE_UNLOAD
1da177e4
LT		 447/* Init the unload section of the module. */
448static void module_unload_init(struct module *mod)
449{
450 unsigned int i;
451
452 INIT_LIST_HEAD(&mod->modules_which_use_me);
453 for (i = 0; i < NR_CPUS; i++)
454 local_set(&mod->ref[i].count, 0);
455 /* Hold reference count during initialization. */
39c715b7 456 local_set(&mod->ref[raw_smp_processor_id()].count, 1);
1da177e4
LT		 457 /* Backwards compatibility macros put refcount during init. */
458 mod->waiter = current;
459}
460
461/* modules using other modules */
462struct module_use
463{
464 struct list_head list;
465 struct module *module_which_uses;
466};
467
468/* Does a already use b? */
469static int already_uses(struct module *a, struct module *b)
470{
471 struct module_use *use;
472
473 list_for_each_entry(use, &b->modules_which_use_me, list) {
474 if (use->module_which_uses == a) {
475 DEBUGP("%s uses %s!\n", a->name, b->name);
476 return 1;
477 }
478 }
479 DEBUGP("%s does not use %s!\n", a->name, b->name);
480 return 0;
481}
482
483/* Module a uses b */
484static int use_module(struct module *a, struct module *b)
485{
486 struct module_use *use;
487 if (b == NULL || already_uses(a, b)) return 1;
488
489 if (!strong_try_module_get(b))
490 return 0;
491
492 DEBUGP("Allocating new usage for %s.\n", a->name);
493 use = kmalloc(sizeof(*use), GFP_ATOMIC);
494 if (!use) {
495 printk("%s: out of memory loading\n", a->name);
496 module_put(b);
497 return 0;
498 }
499
500 use->module_which_uses = a;
501 list_add(&use->list, &b->modules_which_use_me);
502 return 1;
503}
504
505/* Clear the unload stuff of the module. */
506static void module_unload_free(struct module *mod)
507{
508 struct module *i;
509
510 list_for_each_entry(i, &modules, list) {
511 struct module_use *use;
512
513 list_for_each_entry(use, &i->modules_which_use_me, list) {
514 if (use->module_which_uses == mod) {
515 DEBUGP("%s unusing %s\n", mod->name, i->name);
516 module_put(i);
517 list_del(&use->list);
518 kfree(use);
519 /* There can be at most one match. */
520 break;
521 }
522 }
523 }
524}
525
526#ifdef CONFIG_MODULE_FORCE_UNLOAD
fb169793 527static inline int try_force_unload(unsigned int flags)
1da177e4
LT		 528{
529 int ret = (flags & O_TRUNC);
530 if (ret)
fb169793 531 add_taint(TAINT_FORCED_RMMOD);
1da177e4
LT		 532 return ret;
533}
534#else
fb169793 535static inline int try_force_unload(unsigned int flags)
1da177e4
LT		 536{
537 return 0;
538}
539#endif /* CONFIG_MODULE_FORCE_UNLOAD */
540
541struct stopref
542{
543 struct module *mod;
544 int flags;
545 int *forced;
546};
547
548/* Whole machine is stopped with interrupts off when this runs. */
549static int __try_stop_module(void *_sref)
550{
551 struct stopref *sref = _sref;
552
553 /* If it's not unused, quit unless we are told to block. */
554 if ((sref->flags & O_NONBLOCK) && module_refcount(sref->mod) != 0) {
fb169793 555 if (!(*sref->forced = try_force_unload(sref->flags)))
1da177e4
LT		 556 return -EWOULDBLOCK;
557 }
558
559 /* Mark it as dying. */
560 sref->mod->state = MODULE_STATE_GOING;
561 return 0;
562}
563
564static int try_stop_module(struct module *mod, int flags, int *forced)
565{
566 struct stopref sref = { mod, flags, forced };
567
568 return stop_machine_run(__try_stop_module, &sref, NR_CPUS);
569}
570
571unsigned int module_refcount(struct module *mod)
572{
573 unsigned int i, total = 0;
574
575 for (i = 0; i < NR_CPUS; i++)
576 total += local_read(&mod->ref[i].count);
577 return total;
578}
579EXPORT_SYMBOL(module_refcount);
580
581/* This exists whether we can unload or not */
582static void free_module(struct module *mod);
583
584static void wait_for_zero_refcount(struct module *mod)
585{
586 /* Since we might sleep for some time, drop the semaphore first */
6389a385 587 mutex_unlock(&module_mutex);
1da177e4
LT		 588 for (;;) {
589 DEBUGP("Looking at refcount...\n");
590 set_current_state(TASK_UNINTERRUPTIBLE);
591 if (module_refcount(mod) == 0)
592 break;
593 schedule();
594 }
595 current->state = TASK_RUNNING;
6389a385 596 mutex_lock(&module_mutex);
1da177e4
LT		 597}
598
599asmlinkage long
600sys_delete_module(const char __user *name_user, unsigned int flags)
601{
602 struct module *mod;
603 char name[MODULE_NAME_LEN];
604 int ret, forced = 0;
605
606 if (!capable(CAP_SYS_MODULE))
607 return -EPERM;
608
609 if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
610 return -EFAULT;
611 name[MODULE_NAME_LEN-1] = '\0';
612
6389a385 613 if (mutex_lock_interruptible(&module_mutex) != 0)
1da177e4
LT		 614 return -EINTR;
615
616 mod = find_module(name);
617 if (!mod) {
618 ret = -ENOENT;
619 goto out;
620 }
621
622 if (!list_empty(&mod->modules_which_use_me)) {
623 /* Other modules depend on us: get rid of them first. */
624 ret = -EWOULDBLOCK;
625 goto out;
626 }
627
628 /* Doing init or already dying? */
629 if (mod->state != MODULE_STATE_LIVE) {
630 /* FIXME: if (force), slam module count and wake up
631 waiter --RR */
632 DEBUGP("%s already dying\n", mod->name);
633 ret = -EBUSY;
634 goto out;
635 }
636
637 /* If it has an init func, it must have an exit func to unload */
638 if ((mod->init != NULL && mod->exit == NULL)
639 || mod->unsafe) {
fb169793 640 forced = try_force_unload(flags);
1da177e4
LT		 641 if (!forced) {
642 /* This module can't be removed */
643 ret = -EBUSY;
644 goto out;
645 }
646 }
647
648 /* Set this up before setting mod->state */
649 mod->waiter = current;
650
651 /* Stop the machine so refcounts can't move and disable module. */
652 ret = try_stop_module(mod, flags, &forced);
653 if (ret != 0)
654 goto out;
655
656 /* Never wait if forced. */
657 if (!forced && module_refcount(mod) != 0)
658 wait_for_zero_refcount(mod);
659
660 /* Final destruction now noone is using it. */
661 if (mod->exit != NULL) {
6389a385 662 mutex_unlock(&module_mutex);
1da177e4 663 mod->exit();
6389a385 664 mutex_lock(&module_mutex);
1da177e4
LT		 665 }
666 free_module(mod);
667
668 out:
6389a385 669 mutex_unlock(&module_mutex);
1da177e4
LT		 670 return ret;
671}
672
673static void print_unload_info(struct seq_file *m, struct module *mod)
674{
675 struct module_use *use;
676 int printed_something = 0;
677
678 seq_printf(m, " %u ", module_refcount(mod));
679
680 /* Always include a trailing , so userspace can differentiate
681 between this and the old multi-field proc format. */
682 list_for_each_entry(use, &mod->modules_which_use_me, list) {
683 printed_something = 1;
684 seq_printf(m, "%s,", use->module_which_uses->name);
685 }
686
687 if (mod->unsafe) {
688 printed_something = 1;
689 seq_printf(m, "[unsafe],");
690 }
691
692 if (mod->init != NULL && mod->exit == NULL) {
693 printed_something = 1;
694 seq_printf(m, "[permanent],");
695 }
696
697 if (!printed_something)
698 seq_printf(m, "-");
699}
700
701void __symbol_put(const char *symbol)
702{
703 struct module *owner;
704 unsigned long flags;
705 const unsigned long *crc;
706
707 spin_lock_irqsave(&modlist_lock, flags);
708 if (!__find_symbol(symbol, &owner, &crc, 1))
709 BUG();
710 module_put(owner);
711 spin_unlock_irqrestore(&modlist_lock, flags);
712}
713EXPORT_SYMBOL(__symbol_put);
714
715void symbol_put_addr(void *addr)
716{
717 unsigned long flags;
718
719 spin_lock_irqsave(&modlist_lock, flags);
720 if (!kernel_text_address((unsigned long)addr))
721 BUG();
722
723 module_put(module_text_address((unsigned long)addr));
724 spin_unlock_irqrestore(&modlist_lock, flags);
725}
726EXPORT_SYMBOL_GPL(symbol_put_addr);
727
728static ssize_t show_refcnt(struct module_attribute *mattr,
729 struct module *mod, char *buffer)
730{
731 /* sysfs holds a reference */
732 return sprintf(buffer, "%u\n", module_refcount(mod)-1);
733}
734
735static struct module_attribute refcnt = {
736 .attr = { .name = "refcnt", .mode = 0444, .owner = THIS_MODULE },
737 .show = show_refcnt,
738};
739
740#else /* !CONFIG_MODULE_UNLOAD */
741static void print_unload_info(struct seq_file *m, struct module *mod)
742{
743 /* We don't know the usage count, or what modules are using. */
744 seq_printf(m, " - -");
745}
746
747static inline void module_unload_free(struct module *mod)
748{
749}
750
751static inline int use_module(struct module *a, struct module *b)
752{
753 return strong_try_module_get(b);
754}
755
756static inline void module_unload_init(struct module *mod)
757{
758}
759#endif /* CONFIG_MODULE_UNLOAD */
760
03e88ae1
GKH		 761static struct module_attribute *modinfo_attrs[] = {
762 &modinfo_version,
763 &modinfo_srcversion,
764#ifdef CONFIG_MODULE_UNLOAD
765 &refcnt,
766#endif
767 NULL,
768};
769
1da177e4
LT		 770static const char vermagic[] = VERMAGIC_STRING;
771
772#ifdef CONFIG_MODVERSIONS
773static int check_version(Elf_Shdr *sechdrs,
774 unsigned int versindex,
775 const char *symname,
776 struct module *mod,
777 const unsigned long *crc)
778{
779 unsigned int i, num_versions;
780 struct modversion_info *versions;
781
782 /* Exporting module didn't supply crcs? OK, we're already tainted. */
783 if (!crc)
784 return 1;
785
786 versions = (void *) sechdrs[versindex].sh_addr;
787 num_versions = sechdrs[versindex].sh_size
788 / sizeof(struct modversion_info);
789
790 for (i = 0; i < num_versions; i++) {
791 if (strcmp(versions[i].name, symname) != 0)
792 continue;
793
794 if (versions[i].crc == *crc)
795 return 1;
796 printk("%s: disagrees about version of symbol %s\n",
797 mod->name, symname);
798 DEBUGP("Found checksum %lX vs module %lX\n",
799 *crc, versions[i].crc);
800 return 0;
801 }
802 /* Not in module's version table. OK, but that taints the kernel. */
803 if (!(tainted & TAINT_FORCED_MODULE)) {
804 printk("%s: no version for \"%s\" found: kernel tainted.\n",
805 mod->name, symname);
9f158333 806 add_taint(TAINT_FORCED_MODULE);
1da177e4
LT		 807 }
808 return 1;
809}
810
811static inline int check_modstruct_version(Elf_Shdr *sechdrs,
812 unsigned int versindex,
813 struct module *mod)
814{
815 const unsigned long *crc;
816 struct module *owner;
817
818 if (!__find_symbol("struct_module", &owner, &crc, 1))
819 BUG();
820 return check_version(sechdrs, versindex, "struct_module", mod,
821 crc);
822}
823
824/* First part is kernel version, which we ignore. */
825static inline int same_magic(const char *amagic, const char *bmagic)
826{
827 amagic += strcspn(amagic, " ");
828 bmagic += strcspn(bmagic, " ");
829 return strcmp(amagic, bmagic) == 0;
830}
831#else
832static inline int check_version(Elf_Shdr *sechdrs,
833 unsigned int versindex,
834 const char *symname,
835 struct module *mod,
836 const unsigned long *crc)
837{
838 return 1;
839}
840
841static inline int check_modstruct_version(Elf_Shdr *sechdrs,
842 unsigned int versindex,
843 struct module *mod)
844{
845 return 1;
846}
847
848static inline int same_magic(const char *amagic, const char *bmagic)
849{
850 return strcmp(amagic, bmagic) == 0;
851}
852#endif /* CONFIG_MODVERSIONS */
853
854/* Resolve a symbol for this module. I.e. if we find one, record usage.
855 Must be holding module_mutex. */
856static unsigned long resolve_symbol(Elf_Shdr *sechdrs,
857 unsigned int versindex,
858 const char *name,
859 struct module *mod)
860{
861 struct module *owner;
862 unsigned long ret;
863 const unsigned long *crc;
864
1da177e4
LT		 865 ret = __find_symbol(name, &owner, &crc, mod->license_gplok);
866 if (ret) {
867 /* use_module can fail due to OOM, or module unloading */
868 if (!check_version(sechdrs, versindex, name, mod, crc) ||
869 !use_module(mod, owner))
870 ret = 0;
871 }
1da177e4
LT		 872 return ret;
873}
874
875
876/*
877 * /sys/module/foo/sections stuff
878 * J. Corbet <corbet@lwn.net>
879 */
880#ifdef CONFIG_KALLSYMS
881static ssize_t module_sect_show(struct module_attribute *mattr,
882 struct module *mod, char *buf)
883{
884 struct module_sect_attr *sattr =
885 container_of(mattr, struct module_sect_attr, mattr);
886 return sprintf(buf, "0x%lx\n", sattr->address);
887}
888
889static void add_sect_attrs(struct module *mod, unsigned int nsect,
890 char *secstrings, Elf_Shdr *sechdrs)
891{
892 unsigned int nloaded = 0, i, size[2];
893 struct module_sect_attrs *sect_attrs;
894 struct module_sect_attr *sattr;
895 struct attribute **gattr;
896
897 /* Count loaded sections and allocate structures */
898 for (i = 0; i < nsect; i++)
899 if (sechdrs[i].sh_flags & SHF_ALLOC)
900 nloaded++;
901 size[0] = ALIGN(sizeof(*sect_attrs)
902 + nloaded * sizeof(sect_attrs->attrs[0]),
903 sizeof(sect_attrs->grp.attrs[0]));
904 size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]);
905 if (! (sect_attrs = kmalloc(size[0] + size[1], GFP_KERNEL)))
906 return;
907
908 /* Setup section attributes. */
909 sect_attrs->grp.name = "sections";
910 sect_attrs->grp.attrs = (void *)sect_attrs + size[0];
911
912 sattr = &sect_attrs->attrs[0];
913 gattr = &sect_attrs->grp.attrs[0];
914 for (i = 0; i < nsect; i++) {
915 if (! (sechdrs[i].sh_flags & SHF_ALLOC))
916 continue;
917 sattr->address = sechdrs[i].sh_addr;
918 strlcpy(sattr->name, secstrings + sechdrs[i].sh_name,
919 MODULE_SECT_NAME_LEN);
920 sattr->mattr.show = module_sect_show;
921 sattr->mattr.store = NULL;
922 sattr->mattr.attr.name = sattr->name;
923 sattr->mattr.attr.owner = mod;
924 sattr->mattr.attr.mode = S_IRUGO;
925 *(gattr++) = &(sattr++)->mattr.attr;
926 }
927 *gattr = NULL;
928
929 if (sysfs_create_group(&mod->mkobj.kobj, &sect_attrs->grp))
930 goto out;
931
932 mod->sect_attrs = sect_attrs;
933 return;
934 out:
935 kfree(sect_attrs);
936}
937
938static void remove_sect_attrs(struct module *mod)
939{
940 if (mod->sect_attrs) {
941 sysfs_remove_group(&mod->mkobj.kobj,
942 &mod->sect_attrs->grp);
943 /* We are positive that no one is using any sect attrs
944 * at this point. Deallocate immediately. */
945 kfree(mod->sect_attrs);
946 mod->sect_attrs = NULL;
947 }
948}
949
950
951#else
952static inline void add_sect_attrs(struct module *mod, unsigned int nsect,
953 char *sectstrings, Elf_Shdr *sechdrs)
954{
955}
956
957static inline void remove_sect_attrs(struct module *mod)
958{
959}
960#endif /* CONFIG_KALLSYMS */
961
c988d2b2
MD		 962static int module_add_modinfo_attrs(struct module *mod)
963{
964 struct module_attribute *attr;
03e88ae1 965 struct module_attribute *temp_attr;
c988d2b2
MD		 966 int error = 0;
967 int i;
968
03e88ae1
GKH		 969 mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
970 (ARRAY_SIZE(modinfo_attrs) + 1)),
971 GFP_KERNEL);
972 if (!mod->modinfo_attrs)
973 return -ENOMEM;
974
975 temp_attr = mod->modinfo_attrs;
c988d2b2
MD		 976 for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
977 if (!attr->test ||
03e88ae1
GKH		 978 (attr->test && attr->test(mod))) {
979 memcpy(temp_attr, attr, sizeof(*temp_attr));
980 temp_attr->attr.owner = mod;
981 error = sysfs_create_file(&mod->mkobj.kobj,&temp_attr->attr);
982 ++temp_attr;
983 }
c988d2b2
MD		 984 }
985 return error;
986}
987
988static void module_remove_modinfo_attrs(struct module *mod)
989{
990 struct module_attribute *attr;
991 int i;
992
03e88ae1
GKH		 993 for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
994 /* pick a field to test for end of list */
995 if (!attr->attr.name)
996 break;
c988d2b2 997 sysfs_remove_file(&mod->mkobj.kobj,&attr->attr);
03e88ae1
GKH		 998 if (attr->free)
999 attr->free(mod);
c988d2b2 1000 }
03e88ae1 1001 kfree(mod->modinfo_attrs);
c988d2b2 1002}
1da177e4
LT		 1003
1004static int mod_sysfs_setup(struct module *mod,
1005 struct kernel_param *kparam,
1006 unsigned int num_params)
1007{
1008 int err;
1009
1010 memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
1011 err = kobject_set_name(&mod->mkobj.kobj, "%s", mod->name);
1012 if (err)
1013 goto out;
1014 kobj_set_kset_s(&mod->mkobj, module_subsys);
1015 mod->mkobj.mod = mod;
1016 err = kobject_register(&mod->mkobj.kobj);
1017 if (err)
1018 goto out;
1019
1da177e4
LT		 1020 err = module_param_sysfs_setup(mod, kparam, num_params);
1021 if (err)
1022 goto out_unreg;
1023
c988d2b2
MD		 1024 err = module_add_modinfo_attrs(mod);
1025 if (err)
1026 goto out_unreg;
c988d2b2 1027
1da177e4
LT		 1028 return 0;
1029
1030out_unreg:
1031 kobject_unregister(&mod->mkobj.kobj);
1032out:
1033 return err;
1034}
1035
1036static void mod_kobject_remove(struct module *mod)
1037{
c988d2b2 1038 module_remove_modinfo_attrs(mod);
1da177e4
LT		 1039 module_param_sysfs_remove(mod);
1040
1041 kobject_unregister(&mod->mkobj.kobj);
1042}
1043
1044/*
1045 * unlink the module with the whole machine is stopped with interrupts off
1046 * - this defends against kallsyms not taking locks
1047 */
1048static int __unlink_module(void *_mod)
1049{
1050 struct module *mod = _mod;
1051 list_del(&mod->list);
1052 return 0;
1053}
1054
1055/* Free a module, remove from lists, etc (must hold module mutex). */
1056static void free_module(struct module *mod)
1057{
1058 /* Delete from various lists */
1059 stop_machine_run(__unlink_module, mod, NR_CPUS);
1060 remove_sect_attrs(mod);
1061 mod_kobject_remove(mod);
1062
1063 /* Arch-specific cleanup. */
1064 module_arch_cleanup(mod);
1065
1066 /* Module unload stuff */
1067 module_unload_free(mod);
1068
1069 /* This may be NULL, but that's OK */
1070 module_free(mod, mod->module_init);
1071 kfree(mod->args);
1072 if (mod->percpu)
1073 percpu_modfree(mod->percpu);
1074
1075 /* Finally, free the core (containing the module structure) */
1076 module_free(mod, mod->module_core);
1077}
1078
1079void *__symbol_get(const char *symbol)
1080{
1081 struct module *owner;
1082 unsigned long value, flags;
1083 const unsigned long *crc;
1084
1085 spin_lock_irqsave(&modlist_lock, flags);
1086 value = __find_symbol(symbol, &owner, &crc, 1);
1087 if (value && !strong_try_module_get(owner))
1088 value = 0;
1089 spin_unlock_irqrestore(&modlist_lock, flags);
1090
1091 return (void *)value;
1092}
1093EXPORT_SYMBOL_GPL(__symbol_get);
1094
eea8b54d
AN		 1095/*
1096 * Ensure that an exported symbol [global namespace] does not already exist
1097 * in the Kernel or in some other modules exported symbol table.
1098 */
1099static int verify_export_symbols(struct module *mod)
1100{
1101 const char *name = NULL;
1102 unsigned long i, ret = 0;
1103 struct module *owner;
1104 const unsigned long *crc;
1105
1106 for (i = 0; i < mod->num_syms; i++)
1107 if (__find_symbol(mod->syms[i].name, &owner, &crc, 1)) {
1108 name = mod->syms[i].name;
1109 ret = -ENOEXEC;
1110 goto dup;
1111 }
1112
1113 for (i = 0; i < mod->num_gpl_syms; i++)
1114 if (__find_symbol(mod->gpl_syms[i].name, &owner, &crc, 1)) {
1115 name = mod->gpl_syms[i].name;
1116 ret = -ENOEXEC;
1117 goto dup;
1118 }
1119
1120dup:
1121 if (ret)
1122 printk(KERN_ERR "%s: exports duplicate symbol %s (owned by %s)\n",
1123 mod->name, name, module_name(owner));
1124
1125 return ret;
1126}
1127
1da177e4
LT		 1128/* Change all symbols so that sh_value encodes the pointer directly. */
1129static int simplify_symbols(Elf_Shdr *sechdrs,
1130 unsigned int symindex,
1131 const char *strtab,
1132 unsigned int versindex,
1133 unsigned int pcpuindex,
1134 struct module *mod)
1135{
1136 Elf_Sym *sym = (void *)sechdrs[symindex].sh_addr;
1137 unsigned long secbase;
1138 unsigned int i, n = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
1139 int ret = 0;
1140
1141 for (i = 1; i < n; i++) {
1142 switch (sym[i].st_shndx) {
1143 case SHN_COMMON:
1144 /* We compiled with -fno-common. These are not
1145 supposed to happen. */
1146 DEBUGP("Common symbol: %s\n", strtab + sym[i].st_name);
1147 printk("%s: please compile with -fno-common\n",
1148 mod->name);
1149 ret = -ENOEXEC;
1150 break;
1151
1152 case SHN_ABS:
1153 /* Don't need to do anything */
1154 DEBUGP("Absolute symbol: 0x%08lx\n",
1155 (long)sym[i].st_value);
1156 break;
1157
1158 case SHN_UNDEF:
1159 sym[i].st_value
1160 = resolve_symbol(sechdrs, versindex,
1161 strtab + sym[i].st_name, mod);
1162
1163 /* Ok if resolved. */
1164 if (sym[i].st_value != 0)
1165 break;
1166 /* Ok if weak. */
1167 if (ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
1168 break;
1169
1170 printk(KERN_WARNING "%s: Unknown symbol %s\n",
1171 mod->name, strtab + sym[i].st_name);
1172 ret = -ENOENT;
1173 break;
1174
1175 default:
1176 /* Divert to percpu allocation if a percpu var. */
1177 if (sym[i].st_shndx == pcpuindex)
1178 secbase = (unsigned long)mod->percpu;
1179 else
1180 secbase = sechdrs[sym[i].st_shndx].sh_addr;
1181 sym[i].st_value += secbase;
1182 break;
1183 }
1184 }
1185
1186 return ret;
1187}
1188
1189/* Update size with this section: return offset. */
1190static long get_offset(unsigned long *size, Elf_Shdr *sechdr)
1191{
1192 long ret;
1193
1194 ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
1195 *size = ret + sechdr->sh_size;
1196 return ret;
1197}
1198
1199/* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
1200 might -- code, read-only data, read-write data, small data. Tally
1201 sizes, and place the offsets into sh_entsize fields: high bit means it
1202 belongs in init. */
1203static void layout_sections(struct module *mod,
1204 const Elf_Ehdr *hdr,
1205 Elf_Shdr *sechdrs,
1206 const char *secstrings)
1207{
1208 static unsigned long const masks[][2] = {
1209 /* NOTE: all executable code must be the first section
1210 * in this array; otherwise modify the text_size
1211 * finder in the two loops below */
1212 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
1213 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
1214 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
1215 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
1216 };
1217 unsigned int m, i;
1218
1219 for (i = 0; i < hdr->e_shnum; i++)
1220 sechdrs[i].sh_entsize = ~0UL;
1221
1222 DEBUGP("Core section allocation order:\n");
1223 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
1224 for (i = 0; i < hdr->e_shnum; ++i) {
1225 Elf_Shdr *s = &sechdrs[i];
1226
1227 if ((s->sh_flags & masks[m][0]) != masks[m][0]
1228 || (s->sh_flags & masks[m][1])
1229 || s->sh_entsize != ~0UL
1230 || strncmp(secstrings + s->sh_name,
1231 ".init", 5) == 0)
1232 continue;
1233 s->sh_entsize = get_offset(&mod->core_size, s);
1234 DEBUGP("\t%s\n", secstrings + s->sh_name);
1235 }
1236 if (m == 0)
1237 mod->core_text_size = mod->core_size;
1238 }
1239
1240 DEBUGP("Init section allocation order:\n");
1241 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
1242 for (i = 0; i < hdr->e_shnum; ++i) {
1243 Elf_Shdr *s = &sechdrs[i];
1244
1245 if ((s->sh_flags & masks[m][0]) != masks[m][0]
1246 || (s->sh_flags & masks[m][1])
1247 || s->sh_entsize != ~0UL
1248 || strncmp(secstrings + s->sh_name,
1249 ".init", 5) != 0)
1250 continue;
1251 s->sh_entsize = (get_offset(&mod->init_size, s)
1252 | INIT_OFFSET_MASK);
1253 DEBUGP("\t%s\n", secstrings + s->sh_name);
1254 }
1255 if (m == 0)
1256 mod->init_text_size = mod->init_size;
1257 }
1258}
1259
1260static inline int license_is_gpl_compatible(const char *license)
1261{
1262 return (strcmp(license, "GPL") == 0
1263 || strcmp(license, "GPL v2") == 0
1264 || strcmp(license, "GPL and additional rights") == 0
1265 || strcmp(license, "Dual BSD/GPL") == 0
1266 || strcmp(license, "Dual MPL/GPL") == 0);
1267}
1268
1269static void set_license(struct module *mod, const char *license)
1270{
1271 if (!license)
1272 license = "unspecified";
1273
1274 mod->license_gplok = license_is_gpl_compatible(license);
1275 if (!mod->license_gplok && !(tainted & TAINT_PROPRIETARY_MODULE)) {
1276 printk(KERN_WARNING "%s: module license '%s' taints kernel.\n",
1277 mod->name, license);
9f158333 1278 add_taint(TAINT_PROPRIETARY_MODULE);
1da177e4
LT		 1279 }
1280}
1281
1282/* Parse tag=value strings from .modinfo section */
1283static char *next_string(char *string, unsigned long *secsize)
1284{
1285 /* Skip non-zero chars */
1286 while (string[0]) {
1287 string++;
1288 if ((*secsize)-- <= 1)
1289 return NULL;
1290 }
1291
1292 /* Skip any zero padding. */
1293 while (!string[0]) {
1294 string++;
1295 if ((*secsize)-- <= 1)
1296 return NULL;
1297 }
1298 return string;
1299}
1300
1301static char *get_modinfo(Elf_Shdr *sechdrs,
1302 unsigned int info,
1303 const char *tag)
1304{
1305 char *p;
1306 unsigned int taglen = strlen(tag);
1307 unsigned long size = sechdrs[info].sh_size;
1308
1309 for (p = (char *)sechdrs[info].sh_addr; p; p = next_string(p, &size)) {
1310 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
1311 return p + taglen + 1;
1312 }
1313 return NULL;
1314}
1315
c988d2b2
MD		 1316static void setup_modinfo(struct module *mod, Elf_Shdr *sechdrs,
1317 unsigned int infoindex)
1318{
1319 struct module_attribute *attr;
1320 int i;
1321
1322 for (i = 0; (attr = modinfo_attrs[i]); i++) {
1323 if (attr->setup)
1324 attr->setup(mod,
1325 get_modinfo(sechdrs,
1326 infoindex,
1327 attr->attr.name));
1328 }
1329}
c988d2b2 1330
1da177e4
LT		 1331#ifdef CONFIG_KALLSYMS
1332int is_exported(const char *name, const struct module *mod)
1333{
3fd6805f
SR		 1334 if (!mod && lookup_symbol(name, __start___ksymtab, __stop___ksymtab))
1335 return 1;
1336 else
1337 if (lookup_symbol(name, mod->syms, mod->syms + mod->num_syms))
1da177e4 1338 return 1;
3fd6805f
SR		 1339 else
1340 return 0;
1da177e4
LT		 1341}
1342
1343/* As per nm */
1344static char elf_type(const Elf_Sym *sym,
1345 Elf_Shdr *sechdrs,
1346 const char *secstrings,
1347 struct module *mod)
1348{
1349 if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
1350 if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
1351 return 'v';
1352 else
1353 return 'w';
1354 }
1355 if (sym->st_shndx == SHN_UNDEF)
1356 return 'U';
1357 if (sym->st_shndx == SHN_ABS)
1358 return 'a';
1359 if (sym->st_shndx >= SHN_LORESERVE)
1360 return '?';
1361 if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
1362 return 't';
1363 if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
1364 && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
1365 if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
1366 return 'r';
1367 else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
1368 return 'g';
1369 else
1370 return 'd';
1371 }
1372 if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
1373 if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
1374 return 's';
1375 else
1376 return 'b';
1377 }
1378 if (strncmp(secstrings + sechdrs[sym->st_shndx].sh_name,
1379 ".debug", strlen(".debug")) == 0)
1380 return 'n';
1381 return '?';
1382}
1383
1384static void add_kallsyms(struct module *mod,
1385 Elf_Shdr *sechdrs,
1386 unsigned int symindex,
1387 unsigned int strindex,
1388 const char *secstrings)
1389{
1390 unsigned int i;
1391
1392 mod->symtab = (void *)sechdrs[symindex].sh_addr;
1393 mod->num_symtab = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
1394 mod->strtab = (void *)sechdrs[strindex].sh_addr;
1395
1396 /* Set types up while we still have access to sections. */
1397 for (i = 0; i < mod->num_symtab; i++)
1398 mod->symtab[i].st_info
1399 = elf_type(&mod->symtab[i], sechdrs, secstrings, mod);
1400}
1401#else
1402static inline void add_kallsyms(struct module *mod,
1403 Elf_Shdr *sechdrs,
1404 unsigned int symindex,
1405 unsigned int strindex,
1406 const char *secstrings)
1407{
1408}
1409#endif /* CONFIG_KALLSYMS */
1410
1411/* Allocate and load the module: note that size of section 0 is always
1412 zero, and we rely on this for optional sections. */
1413static struct module *load_module(void __user *umod,
1414 unsigned long len,
1415 const char __user *uargs)
1416{
1417 Elf_Ehdr *hdr;
1418 Elf_Shdr *sechdrs;
1419 char *secstrings, *args, *modmagic, *strtab = NULL;
1420 unsigned int i, symindex = 0, strindex = 0, setupindex, exindex,
1421 exportindex, modindex, obsparmindex, infoindex, gplindex,
9f28bb7e
GKH		 1422 crcindex, gplcrcindex, versindex, pcpuindex, gplfutureindex,
1423 gplfuturecrcindex;
1da177e4
LT		 1424 struct module *mod;
1425 long err = 0;
1426 void *percpu = NULL, *ptr = NULL; /* Stops spurious gcc warning */
1427 struct exception_table_entry *extable;
378bac82 1428 mm_segment_t old_fs;
1da177e4
LT		 1429
1430 DEBUGP("load_module: umod=%p, len=%lu, uargs=%p\n",
1431 umod, len, uargs);
1432 if (len < sizeof(*hdr))
1433 return ERR_PTR(-ENOEXEC);
1434
1435 /* Suck in entire file: we'll want most of it. */
1436 /* vmalloc barfs on "unusual" numbers. Check here */
1437 if (len > 64 * 1024 * 1024 || (hdr = vmalloc(len)) == NULL)
1438 return ERR_PTR(-ENOMEM);
1439 if (copy_from_user(hdr, umod, len) != 0) {
1440 err = -EFAULT;
1441 goto free_hdr;
1442 }
1443
1444 /* Sanity checks against insmoding binaries or wrong arch,
1445 weird elf version */
1446 if (memcmp(hdr->e_ident, ELFMAG, 4) != 0
1447 || hdr->e_type != ET_REL
1448 || !elf_check_arch(hdr)
1449 || hdr->e_shentsize != sizeof(*sechdrs)) {
1450 err = -ENOEXEC;
1451 goto free_hdr;
1452 }
1453
1454 if (len < hdr->e_shoff + hdr->e_shnum * sizeof(Elf_Shdr))
1455 goto truncated;
1456
1457 /* Convenience variables */
1458 sechdrs = (void *)hdr + hdr->e_shoff;
1459 secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
1460 sechdrs[0].sh_addr = 0;
1461
1462 for (i = 1; i < hdr->e_shnum; i++) {
1463 if (sechdrs[i].sh_type != SHT_NOBITS
1464 && len < sechdrs[i].sh_offset + sechdrs[i].sh_size)
1465 goto truncated;
1466
1467 /* Mark all sections sh_addr with their address in the
1468 temporary image. */
1469 sechdrs[i].sh_addr = (size_t)hdr + sechdrs[i].sh_offset;
1470
1471 /* Internal symbols and strings. */
1472 if (sechdrs[i].sh_type == SHT_SYMTAB) {
1473 symindex = i;
1474 strindex = sechdrs[i].sh_link;
1475 strtab = (char *)hdr + sechdrs[strindex].sh_offset;
1476 }
1477#ifndef CONFIG_MODULE_UNLOAD
1478 /* Don't load .exit sections */
1479 if (strncmp(secstrings+sechdrs[i].sh_name, ".exit", 5) == 0)
1480 sechdrs[i].sh_flags &= ~(unsigned long)SHF_ALLOC;
1481#endif
1482 }
1483
1484 modindex = find_sec(hdr, sechdrs, secstrings,
1485 ".gnu.linkonce.this_module");
1486 if (!modindex) {
1487 printk(KERN_WARNING "No module found in object\n");
1488 err = -ENOEXEC;
1489 goto free_hdr;
1490 }
1491 mod = (void *)sechdrs[modindex].sh_addr;
1492
1493 if (symindex == 0) {
1494 printk(KERN_WARNING "%s: module has no symbols (stripped?)\n",
1495 mod->name);
1496 err = -ENOEXEC;
1497 goto free_hdr;
1498 }
1499
1500 /* Optional sections */
1501 exportindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab");
1502 gplindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_gpl");
9f28bb7e 1503 gplfutureindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_gpl_future");
1da177e4
LT		 1504 crcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab");
1505 gplcrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_gpl");
9f28bb7e 1506 gplfuturecrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_gpl_future");
1da177e4
LT		 1507 setupindex = find_sec(hdr, sechdrs, secstrings, "__param");
1508 exindex = find_sec(hdr, sechdrs, secstrings, "__ex_table");
1509 obsparmindex = find_sec(hdr, sechdrs, secstrings, "__obsparm");
1510 versindex = find_sec(hdr, sechdrs, secstrings, "__versions");
1511 infoindex = find_sec(hdr, sechdrs, secstrings, ".modinfo");
1512 pcpuindex = find_pcpusec(hdr, sechdrs, secstrings);
1513
1514 /* Don't keep modinfo section */
1515 sechdrs[infoindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
1516#ifdef CONFIG_KALLSYMS
1517 /* Keep symbol and string tables for decoding later. */
1518 sechdrs[symindex].sh_flags |= SHF_ALLOC;
1519 sechdrs[strindex].sh_flags |= SHF_ALLOC;
1520#endif
1521
1522 /* Check module struct version now, before we try to use module. */
1523 if (!check_modstruct_version(sechdrs, versindex, mod)) {
1524 err = -ENOEXEC;
1525 goto free_hdr;
1526 }
1527
1528 modmagic = get_modinfo(sechdrs, infoindex, "vermagic");
1529 /* This is allowed: modprobe --force will invalidate it. */
1530 if (!modmagic) {
9f158333 1531 add_taint(TAINT_FORCED_MODULE);
1da177e4
LT		 1532 printk(KERN_WARNING "%s: no version magic, tainting kernel.\n",
1533 mod->name);
1534 } else if (!same_magic(modmagic, vermagic)) {
1535 printk(KERN_ERR "%s: version magic '%s' should be '%s'\n",
1536 mod->name, modmagic, vermagic);
1537 err = -ENOEXEC;
1538 goto free_hdr;
1539 }
1540
1541 /* Now copy in args */
24277dda
DA		 1542 args = strndup_user(uargs, ~0UL >> 1);
1543 if (IS_ERR(args)) {
1544 err = PTR_ERR(args);
1da177e4
LT		 1545 goto free_hdr;
1546 }
8e08b756 1547
1da177e4
LT		 1548 if (find_module(mod->name)) {
1549 err = -EEXIST;
1550 goto free_mod;
1551 }
1552
1553 mod->state = MODULE_STATE_COMING;
1554
1555 /* Allow arches to frob section contents and sizes. */
1556 err = module_frob_arch_sections(hdr, sechdrs, secstrings, mod);
1557 if (err < 0)
1558 goto free_mod;
1559
1560 if (pcpuindex) {
1561 /* We have a special allocation for this section. */
1562 percpu = percpu_modalloc(sechdrs[pcpuindex].sh_size,
842bbaaa
RR		 1563 sechdrs[pcpuindex].sh_addralign,
1564 mod->name);
1da177e4
LT		 1565 if (!percpu) {
1566 err = -ENOMEM;
1567 goto free_mod;
1568 }
1569 sechdrs[pcpuindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
1570 mod->percpu = percpu;
1571 }
1572
1573 /* Determine total sizes, and put offsets in sh_entsize. For now
1574 this is done generically; there doesn't appear to be any
1575 special cases for the architectures. */
1576 layout_sections(mod, hdr, sechdrs, secstrings);
1577
1578 /* Do the allocs. */
1579 ptr = module_alloc(mod->core_size);
1580 if (!ptr) {
1581 err = -ENOMEM;
1582 goto free_percpu;
1583 }
1584 memset(ptr, 0, mod->core_size);
1585 mod->module_core = ptr;
1586
1587 ptr = module_alloc(mod->init_size);
1588 if (!ptr && mod->init_size) {
1589 err = -ENOMEM;
1590 goto free_core;
1591 }
1592 memset(ptr, 0, mod->init_size);
1593 mod->module_init = ptr;
1594
1595 /* Transfer each section which specifies SHF_ALLOC */
1596 DEBUGP("final section addresses:\n");
1597 for (i = 0; i < hdr->e_shnum; i++) {
1598 void *dest;
1599
1600 if (!(sechdrs[i].sh_flags & SHF_ALLOC))
1601 continue;
1602
1603 if (sechdrs[i].sh_entsize & INIT_OFFSET_MASK)
1604 dest = mod->module_init
1605 + (sechdrs[i].sh_entsize & ~INIT_OFFSET_MASK);
1606 else
1607 dest = mod->module_core + sechdrs[i].sh_entsize;
1608
1609 if (sechdrs[i].sh_type != SHT_NOBITS)
1610 memcpy(dest, (void *)sechdrs[i].sh_addr,
1611 sechdrs[i].sh_size);
1612 /* Update sh_addr to point to copy in image. */
1613 sechdrs[i].sh_addr = (unsigned long)dest;
1614 DEBUGP("\t0x%lx %s\n", sechdrs[i].sh_addr, secstrings + sechdrs[i].sh_name);
1615 }
1616 /* Module has been moved. */
1617 mod = (void *)sechdrs[modindex].sh_addr;
1618
1619 /* Now we've moved module, initialize linked lists, etc. */
1620 module_unload_init(mod);
1621
1622 /* Set up license info based on the info section */
1623 set_license(mod, get_modinfo(sechdrs, infoindex, "license"));
1624
9841d61d
DJ		 1625 if (strcmp(mod->name, "ndiswrapper") == 0)
1626 add_taint(TAINT_PROPRIETARY_MODULE);
1627 if (strcmp(mod->name, "driverloader") == 0)
1628 add_taint(TAINT_PROPRIETARY_MODULE);
1629
c988d2b2
MD		 1630 /* Set up MODINFO_ATTR fields */
1631 setup_modinfo(mod, sechdrs, infoindex);
c988d2b2 1632
1da177e4
LT		 1633 /* Fix up syms, so that st_value is a pointer to location. */
1634 err = simplify_symbols(sechdrs, symindex, strtab, versindex, pcpuindex,
1635 mod);
1636 if (err < 0)
1637 goto cleanup;
1638
1639 /* Set up EXPORTed & EXPORT_GPLed symbols (section 0 is 0 length) */
1640 mod->num_syms = sechdrs[exportindex].sh_size / sizeof(*mod->syms);
1641 mod->syms = (void *)sechdrs[exportindex].sh_addr;
1642 if (crcindex)
1643 mod->crcs = (void *)sechdrs[crcindex].sh_addr;
1644 mod->num_gpl_syms = sechdrs[gplindex].sh_size / sizeof(*mod->gpl_syms);
1645 mod->gpl_syms = (void *)sechdrs[gplindex].sh_addr;
1646 if (gplcrcindex)
1647 mod->gpl_crcs = (void *)sechdrs[gplcrcindex].sh_addr;
9f28bb7e
GKH		 1648 mod->num_gpl_future_syms = sechdrs[gplfutureindex].sh_size /
1649 sizeof(*mod->gpl_future_syms);
1650 mod->gpl_future_syms = (void *)sechdrs[gplfutureindex].sh_addr;
1651 if (gplfuturecrcindex)
1652 mod->gpl_future_crcs = (void *)sechdrs[gplfuturecrcindex].sh_addr;
1da177e4
LT		 1653
1654#ifdef CONFIG_MODVERSIONS
1655 if ((mod->num_syms && !crcindex) ||
9f28bb7e
GKH		 1656 (mod->num_gpl_syms && !gplcrcindex) ||
1657 (mod->num_gpl_future_syms && !gplfuturecrcindex)) {
1da177e4
LT		 1658 printk(KERN_WARNING "%s: No versions for exported symbols."
1659 " Tainting kernel.\n", mod->name);
9f158333 1660 add_taint(TAINT_FORCED_MODULE);
1da177e4
LT		 1661 }
1662#endif
1663
1664 /* Now do relocations. */
1665 for (i = 1; i < hdr->e_shnum; i++) {
1666 const char *strtab = (char *)sechdrs[strindex].sh_addr;
1667 unsigned int info = sechdrs[i].sh_info;
1668
1669 /* Not a valid relocation section? */
1670 if (info >= hdr->e_shnum)
1671 continue;
1672
1673 /* Don't bother with non-allocated sections */
1674 if (!(sechdrs[info].sh_flags & SHF_ALLOC))
1675 continue;
1676
1677 if (sechdrs[i].sh_type == SHT_REL)
1678 err = apply_relocate(sechdrs, strtab, symindex, i,mod);
1679 else if (sechdrs[i].sh_type == SHT_RELA)
1680 err = apply_relocate_add(sechdrs, strtab, symindex, i,
1681 mod);
1682 if (err < 0)
1683 goto cleanup;
1684 }
1685
eea8b54d
AN		 1686 /* Find duplicate symbols */
1687 err = verify_export_symbols(mod);
1688
1689 if (err < 0)
1690 goto cleanup;
1691
1da177e4
LT		 1692 /* Set up and sort exception table */
1693 mod->num_exentries = sechdrs[exindex].sh_size / sizeof(*mod->extable);
1694 mod->extable = extable = (void *)sechdrs[exindex].sh_addr;
1695 sort_extable(extable, extable + mod->num_exentries);
1696
1697 /* Finally, copy percpu area over. */
1698 percpu_modcopy(mod->percpu, (void *)sechdrs[pcpuindex].sh_addr,
1699 sechdrs[pcpuindex].sh_size);
1700
1701 add_kallsyms(mod, sechdrs, symindex, strindex, secstrings);
1702
1703 err = module_finalize(hdr, sechdrs, mod);
1704 if (err < 0)
1705 goto cleanup;
1706
378bac82
TK		 1707 /* flush the icache in correct context */
1708 old_fs = get_fs();
1709 set_fs(KERNEL_DS);
1710
1711 /*
1712 * Flush the instruction cache, since we've played with text.
1713 * Do it before processing of module parameters, so the module
1714 * can provide parameter accessor functions of its own.
1715 */
1716 if (mod->module_init)
1717 flush_icache_range((unsigned long)mod->module_init,
1718 (unsigned long)mod->module_init
1719 + mod->init_size);
1720 flush_icache_range((unsigned long)mod->module_core,
1721 (unsigned long)mod->module_core + mod->core_size);
1722
1723 set_fs(old_fs);
1724
1da177e4 1725 mod->args = args;
8d3b33f6
RR		 1726 if (obsparmindex)
1727 printk(KERN_WARNING "%s: Ignoring obsolete parameters\n",
1728 mod->name);
1729
1730 /* Size of section 0 is 0, so this works well if no params */
1731 err = parse_args(mod->name, mod->args,
1732 (struct kernel_param *)
1733 sechdrs[setupindex].sh_addr,
1734 sechdrs[setupindex].sh_size
1735 / sizeof(struct kernel_param),
1736 NULL);
1da177e4
LT		 1737 if (err < 0)
1738 goto arch_cleanup;
1739
1740 err = mod_sysfs_setup(mod,
1741 (struct kernel_param *)
1742 sechdrs[setupindex].sh_addr,
1743 sechdrs[setupindex].sh_size
1744 / sizeof(struct kernel_param));
1745 if (err < 0)
1746 goto arch_cleanup;
1747 add_sect_attrs(mod, hdr->e_shnum, secstrings, sechdrs);
1748
1749 /* Get rid of temporary copy */
1750 vfree(hdr);
1751
1752 /* Done! */
1753 return mod;
1754
1755 arch_cleanup:
1756 module_arch_cleanup(mod);
1757 cleanup:
1758 module_unload_free(mod);
1759 module_free(mod, mod->module_init);
1760 free_core:
1761 module_free(mod, mod->module_core);
1762 free_percpu:
1763 if (percpu)
1764 percpu_modfree(percpu);
1765 free_mod:
1766 kfree(args);
1767 free_hdr:
1768 vfree(hdr);
6fe2e70b 1769 return ERR_PTR(err);
1da177e4
LT		 1770
1771 truncated:
1772 printk(KERN_ERR "Module len %lu truncated\n", len);
1773 err = -ENOEXEC;
1774 goto free_hdr;
1775}
1776
1777/*
1778 * link the module with the whole machine is stopped with interrupts off
1779 * - this defends against kallsyms not taking locks
1780 */
1781static int __link_module(void *_mod)
1782{
1783 struct module *mod = _mod;
1784 list_add(&mod->list, &modules);
1785 return 0;
1786}
1787
1788/* This is where the real work happens */
1789asmlinkage long
1790sys_init_module(void __user *umod,
1791 unsigned long len,
1792 const char __user *uargs)
1793{
1794 struct module *mod;
1795 int ret = 0;
1796
1797 /* Must have permission */
1798 if (!capable(CAP_SYS_MODULE))
1799 return -EPERM;
1800
1801 /* Only one module load at a time, please */
6389a385 1802 if (mutex_lock_interruptible(&module_mutex) != 0)
1da177e4
LT		 1803 return -EINTR;
1804
1805 /* Do all the hard work */
1806 mod = load_module(umod, len, uargs);
1807 if (IS_ERR(mod)) {
6389a385 1808 mutex_unlock(&module_mutex);
1da177e4
LT		 1809 return PTR_ERR(mod);
1810 }
1811
1da177e4
LT		 1812 /* Now sew it into the lists. They won't access us, since
1813 strong_try_module_get() will fail. */
1814 stop_machine_run(__link_module, mod, NR_CPUS);
1815
1816 /* Drop lock so they can recurse */
6389a385 1817 mutex_unlock(&module_mutex);
1da177e4 1818
97d1f15b 1819 mutex_lock(&notify_mutex);
1da177e4 1820 notifier_call_chain(&module_notify_list, MODULE_STATE_COMING, mod);
97d1f15b 1821 mutex_unlock(&notify_mutex);
1da177e4
LT		 1822
1823 /* Start the module */
1824 if (mod->init != NULL)
1825 ret = mod->init();
1826 if (ret < 0) {
1827 /* Init routine failed: abort. Try to protect us from
1828 buggy refcounters. */
1829 mod->state = MODULE_STATE_GOING;
fbd568a3 1830 synchronize_sched();
1da177e4
LT		 1831 if (mod->unsafe)
1832 printk(KERN_ERR "%s: module is now stuck!\n",
1833 mod->name);
1834 else {
1835 module_put(mod);
6389a385 1836 mutex_lock(&module_mutex);
1da177e4 1837 free_module(mod);
6389a385 1838 mutex_unlock(&module_mutex);
1da177e4
LT		 1839 }
1840 return ret;
1841 }
1842
1843 /* Now it's a first class citizen! */
6389a385 1844 mutex_lock(&module_mutex);
1da177e4
LT		 1845 mod->state = MODULE_STATE_LIVE;
1846 /* Drop initial reference. */
1847 module_put(mod);
1848 module_free(mod, mod->module_init);
1849 mod->module_init = NULL;
1850 mod->init_size = 0;
1851 mod->init_text_size = 0;
6389a385 1852 mutex_unlock(&module_mutex);
1da177e4
LT		 1853
1854 return 0;
1855}
1856
1857static inline int within(unsigned long addr, void *start, unsigned long size)
1858{
1859 return ((void *)addr >= start && (void *)addr < start + size);
1860}
1861
1862#ifdef CONFIG_KALLSYMS
1863/*
1864 * This ignores the intensely annoying "mapping symbols" found
1865 * in ARM ELF files: $a, $t and $d.
1866 */
1867static inline int is_arm_mapping_symbol(const char *str)
1868{
1869 return str[0] == '$' && strchr("atd", str[1])
1870 && (str[2] == '\0' || str[2] == '.');
1871}
1872
1873static const char *get_ksymbol(struct module *mod,
1874 unsigned long addr,
1875 unsigned long *size,
1876 unsigned long *offset)
1877{
1878 unsigned int i, best = 0;
1879 unsigned long nextval;
1880
1881 /* At worse, next value is at end of module */
1882 if (within(addr, mod->module_init, mod->init_size))
1883 nextval = (unsigned long)mod->module_init+mod->init_text_size;
1884 else
1885 nextval = (unsigned long)mod->module_core+mod->core_text_size;
1886
1887 /* Scan for closest preceeding symbol, and next symbol. (ELF
1888 starts real symbols at 1). */
1889 for (i = 1; i < mod->num_symtab; i++) {
1890 if (mod->symtab[i].st_shndx == SHN_UNDEF)
1891 continue;
1892
1893 /* We ignore unnamed symbols: they're uninformative
1894 * and inserted at a whim. */
1895 if (mod->symtab[i].st_value <= addr
1896 && mod->symtab[i].st_value > mod->symtab[best].st_value
1897 && *(mod->strtab + mod->symtab[i].st_name) != '\0'
1898 && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
1899 best = i;
1900 if (mod->symtab[i].st_value > addr
1901 && mod->symtab[i].st_value < nextval
1902 && *(mod->strtab + mod->symtab[i].st_name) != '\0'
1903 && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
1904 nextval = mod->symtab[i].st_value;
1905 }
1906
1907 if (!best)
1908 return NULL;
1909
1910 *size = nextval - mod->symtab[best].st_value;
1911 *offset = addr - mod->symtab[best].st_value;
1912 return mod->strtab + mod->symtab[best].st_name;
1913}
1914
1915/* For kallsyms to ask for address resolution. NULL means not found.
1916 We don't lock, as this is used for oops resolution and races are a
1917 lesser concern. */
1918const char *module_address_lookup(unsigned long addr,
1919 unsigned long *size,
1920 unsigned long *offset,
1921 char **modname)
1922{
1923 struct module *mod;
1924
1925 list_for_each_entry(mod, &modules, list) {
1926 if (within(addr, mod->module_init, mod->init_size)
1927 || within(addr, mod->module_core, mod->core_size)) {
1928 *modname = mod->name;
1929 return get_ksymbol(mod, addr, size, offset);
1930 }
1931 }
1932 return NULL;
1933}
1934
1935struct module *module_get_kallsym(unsigned int symnum,
1936 unsigned long *value,
1937 char *type,
1938 char namebuf[128])
1939{
1940 struct module *mod;
1941
6389a385 1942 mutex_lock(&module_mutex);
1da177e4
LT		 1943 list_for_each_entry(mod, &modules, list) {
1944 if (symnum < mod->num_symtab) {
1945 *value = mod->symtab[symnum].st_value;
1946 *type = mod->symtab[symnum].st_info;
1947 strncpy(namebuf,
1948 mod->strtab + mod->symtab[symnum].st_name,
1949 127);
6389a385 1950 mutex_unlock(&module_mutex);
1da177e4
LT		 1951 return mod;
1952 }
1953 symnum -= mod->num_symtab;
1954 }
6389a385 1955 mutex_unlock(&module_mutex);
1da177e4
LT		 1956 return NULL;
1957}
1958
1959static unsigned long mod_find_symname(struct module *mod, const char *name)
1960{
1961 unsigned int i;
1962
1963 for (i = 0; i < mod->num_symtab; i++)
54e8ce46
KO		 1964 if (strcmp(name, mod->strtab+mod->symtab[i].st_name) == 0 &&
1965 mod->symtab[i].st_info != 'U')
1da177e4
LT		 1966 return mod->symtab[i].st_value;
1967 return 0;
1968}
1969
1970/* Look for this name: can be of form module:name. */
1971unsigned long module_kallsyms_lookup_name(const char *name)
1972{
1973 struct module *mod;
1974 char *colon;
1975 unsigned long ret = 0;
1976
1977 /* Don't lock: we're in enough trouble already. */
1978 if ((colon = strchr(name, ':')) != NULL) {
1979 *colon = '\0';
1980 if ((mod = find_module(name)) != NULL)
1981 ret = mod_find_symname(mod, colon+1);
1982 *colon = ':';
1983 } else {
1984 list_for_each_entry(mod, &modules, list)
1985 if ((ret = mod_find_symname(mod, name)) != 0)
1986 break;
1987 }
1988 return ret;
1989}
1990#endif /* CONFIG_KALLSYMS */
1991
1992/* Called by the /proc file system to return a list of modules. */
1993static void *m_start(struct seq_file *m, loff_t *pos)
1994{
1995 struct list_head *i;
1996 loff_t n = 0;
1997
6389a385 1998 mutex_lock(&module_mutex);
1da177e4
LT		 1999 list_for_each(i, &modules) {
2000 if (n++ == *pos)
2001 break;
2002 }
2003 if (i == &modules)
2004 return NULL;
2005 return i;
2006}
2007
2008static void *m_next(struct seq_file *m, void *p, loff_t *pos)
2009{
2010 struct list_head *i = p;
2011 (*pos)++;
2012 if (i->next == &modules)
2013 return NULL;
2014 return i->next;
2015}
2016
2017static void m_stop(struct seq_file *m, void *p)
2018{
6389a385 2019 mutex_unlock(&module_mutex);
1da177e4
LT		 2020}
2021
2022static int m_show(struct seq_file *m, void *p)
2023{
2024 struct module *mod = list_entry(p, struct module, list);
2025 seq_printf(m, "%s %lu",
2026 mod->name, mod->init_size + mod->core_size);
2027 print_unload_info(m, mod);
2028
2029 /* Informative for users. */
2030 seq_printf(m, " %s",
2031 mod->state == MODULE_STATE_GOING ? "Unloading":
2032 mod->state == MODULE_STATE_COMING ? "Loading":
2033 "Live");
2034 /* Used by oprofile and other similar tools. */
2035 seq_printf(m, " 0x%p", mod->module_core);
2036
2037 seq_printf(m, "\n");
2038 return 0;
2039}
2040
2041/* Format: modulename size refcount deps address
2042
2043 Where refcount is a number or -, and deps is a comma-separated list
2044 of depends or -.
2045*/
2046struct seq_operations modules_op = {
2047 .start = m_start,
2048 .next = m_next,
2049 .stop = m_stop,
2050 .show = m_show
2051};
2052
2053/* Given an address, look for it in the module exception tables. */
2054const struct exception_table_entry *search_module_extables(unsigned long addr)
2055{
2056 unsigned long flags;
2057 const struct exception_table_entry *e = NULL;
2058 struct module *mod;
2059
2060 spin_lock_irqsave(&modlist_lock, flags);
2061 list_for_each_entry(mod, &modules, list) {
2062 if (mod->num_exentries == 0)
2063 continue;
2064
2065 e = search_extable(mod->extable,
2066 mod->extable + mod->num_exentries - 1,
2067 addr);
2068 if (e)
2069 break;
2070 }
2071 spin_unlock_irqrestore(&modlist_lock, flags);
2072
2073 /* Now, if we found one, we are running inside it now, hence
2074 we cannot unload the module, hence no refcnt needed. */
2075 return e;
2076}
2077
2078/* Is this a valid kernel address? We don't grab the lock: we are oopsing. */
2079struct module *__module_text_address(unsigned long addr)
2080{
2081 struct module *mod;
2082
2083 list_for_each_entry(mod, &modules, list)
2084 if (within(addr, mod->module_init, mod->init_text_size)
2085 || within(addr, mod->module_core, mod->core_text_size))
2086 return mod;
2087 return NULL;
2088}
2089
2090struct module *module_text_address(unsigned long addr)
2091{
2092 struct module *mod;
2093 unsigned long flags;
2094
2095 spin_lock_irqsave(&modlist_lock, flags);
2096 mod = __module_text_address(addr);
2097 spin_unlock_irqrestore(&modlist_lock, flags);
2098
2099 return mod;
2100}
2101
2102/* Don't grab lock, we're oopsing. */
2103void print_modules(void)
2104{
2105 struct module *mod;
2106
2107 printk("Modules linked in:");
2108 list_for_each_entry(mod, &modules, list)
2109 printk(" %s", mod->name);
2110 printk("\n");
2111}
2112
2113void module_add_driver(struct module *mod, struct device_driver *drv)
2114{
2115 if (!mod || !drv)
2116 return;
2117
2118 /* Don't check return code; this call is idempotent */
2119 sysfs_create_link(&drv->kobj, &mod->mkobj.kobj, "module");
2120}
2121EXPORT_SYMBOL(module_add_driver);
2122
2123void module_remove_driver(struct device_driver *drv)
2124{
2125 if (!drv)
2126 return;
2127 sysfs_remove_link(&drv->kobj, "module");
2128}
2129EXPORT_SYMBOL(module_remove_driver);
2130
2131#ifdef CONFIG_MODVERSIONS
2132/* Generate the signature for struct module here, too, for modversions. */
2133void struct_module(struct module *mod) { return; }
2134EXPORT_SYMBOL(struct_module);
2135#endif
Linux 6.x block layer and io_uring tree(s)