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[PATCH] mark address_space_operations const
[linux-2.6-block.git] / kernel / module.c
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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>
4552d5dc 43#include <linux/unwind.h>
1da177e4
LT		 44#include <asm/uaccess.h>
45#include <asm/semaphore.h>
46#include <asm/cacheflush.h>
b817f6fe 47#include <linux/license.h>
1da177e4
LT		 48
49#if 0
50#define DEBUGP printk
51#else
52#define DEBUGP(fmt , a...)
53#endif
54
55#ifndef ARCH_SHF_SMALL
56#define ARCH_SHF_SMALL 0
57#endif
58
59/* If this is set, the section belongs in the init part of the module */
60#define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
61
62/* Protects module list */
63static DEFINE_SPINLOCK(modlist_lock);
64
65/* List of modules, protected by module_mutex AND modlist_lock */
6389a385 66static DEFINE_MUTEX(module_mutex);
1da177e4
LT		 67static LIST_HEAD(modules);
68
e041c683 69static BLOCKING_NOTIFIER_HEAD(module_notify_list);
1da177e4
LT		 70
71int register_module_notifier(struct notifier_block * nb)
72{
e041c683 73 return blocking_notifier_chain_register(&module_notify_list, nb);
1da177e4
LT		 74}
75EXPORT_SYMBOL(register_module_notifier);
76
77int unregister_module_notifier(struct notifier_block * nb)
78{
e041c683 79 return blocking_notifier_chain_unregister(&module_notify_list, nb);
1da177e4
LT		 80}
81EXPORT_SYMBOL(unregister_module_notifier);
82
83/* We require a truly strong try_module_get() */
84static inline int strong_try_module_get(struct module *mod)
85{
86 if (mod && mod->state == MODULE_STATE_COMING)
87 return 0;
88 return try_module_get(mod);
89}
90
91/* A thread that wants to hold a reference to a module only while it
92 * is running can call ths to safely exit.
93 * nfsd and lockd use this.
94 */
95void __module_put_and_exit(struct module *mod, long code)
96{
97 module_put(mod);
98 do_exit(code);
99}
100EXPORT_SYMBOL(__module_put_and_exit);
101
102/* Find a module section: 0 means not found. */
103static unsigned int find_sec(Elf_Ehdr *hdr,
104 Elf_Shdr *sechdrs,
105 const char *secstrings,
106 const char *name)
107{
108 unsigned int i;
109
110 for (i = 1; i < hdr->e_shnum; i++)
111 /* Alloc bit cleared means "ignore it." */
112 if ((sechdrs[i].sh_flags & SHF_ALLOC)
113 && strcmp(secstrings+sechdrs[i].sh_name, name) == 0)
114 return i;
115 return 0;
116}
117
118/* Provided by the linker */
119extern const struct kernel_symbol __start___ksymtab[];
120extern const struct kernel_symbol __stop___ksymtab[];
121extern const struct kernel_symbol __start___ksymtab_gpl[];
122extern const struct kernel_symbol __stop___ksymtab_gpl[];
9f28bb7e
GKH		 123extern const struct kernel_symbol __start___ksymtab_gpl_future[];
124extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
1da177e4
LT		 125extern const unsigned long __start___kcrctab[];
126extern const unsigned long __start___kcrctab_gpl[];
9f28bb7e 127extern const unsigned long __start___kcrctab_gpl_future[];
1da177e4
LT		 128
129#ifndef CONFIG_MODVERSIONS
130#define symversion(base, idx) NULL
131#else
f83ca9fe 132#define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
1da177e4
LT		 133#endif
134
3fd6805f
SR		 135/* lookup symbol in given range of kernel_symbols */
136static const struct kernel_symbol *lookup_symbol(const char *name,
137 const struct kernel_symbol *start,
138 const struct kernel_symbol *stop)
139{
140 const struct kernel_symbol *ks = start;
141 for (; ks < stop; ks++)
142 if (strcmp(ks->name, name) == 0)
143 return ks;
144 return NULL;
145}
146
1da177e4
LT		 147/* Find a symbol, return value, crc and module which owns it */
148static unsigned long __find_symbol(const char *name,
149 struct module **owner,
150 const unsigned long **crc,
151 int gplok)
152{
153 struct module *mod;
3fd6805f 154 const struct kernel_symbol *ks;
1da177e4
LT		 155
156 /* Core kernel first. */
157 *owner = NULL;
3fd6805f
SR		 158 ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
159 if (ks) {
160 *crc = symversion(__start___kcrctab, (ks - __start___ksymtab));
161 return ks->value;
1da177e4
LT		 162 }
163 if (gplok) {
3fd6805f
SR		 164 ks = lookup_symbol(name, __start___ksymtab_gpl,
165 __stop___ksymtab_gpl);
166 if (ks) {
167 *crc = symversion(__start___kcrctab_gpl,
168 (ks - __start___ksymtab_gpl));
169 return ks->value;
170 }
1da177e4 171 }
9f28bb7e
GKH		 172 ks = lookup_symbol(name, __start___ksymtab_gpl_future,
173 __stop___ksymtab_gpl_future);
174 if (ks) {
175 if (!gplok) {
176 printk(KERN_WARNING "Symbol %s is being used "
177 "by a non-GPL module, which will not "
178 "be allowed in the future\n", name);
179 printk(KERN_WARNING "Please see the file "
180 "Documentation/feature-removal-schedule.txt "
181 "in the kernel source tree for more "
182 "details.\n");
183 }
184 *crc = symversion(__start___kcrctab_gpl_future,
185 (ks - __start___ksymtab_gpl_future));
186 return ks->value;
187 }
1da177e4
LT		 188
189 /* Now try modules. */
190 list_for_each_entry(mod, &modules, list) {
191 *owner = mod;
3fd6805f
SR		 192 ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
193 if (ks) {
194 *crc = symversion(mod->crcs, (ks - mod->syms));
195 return ks->value;
196 }
1da177e4
LT		 197
198 if (gplok) {
3fd6805f
SR		 199 ks = lookup_symbol(name, mod->gpl_syms,
200 mod->gpl_syms + mod->num_gpl_syms);
201 if (ks) {
202 *crc = symversion(mod->gpl_crcs,
203 (ks - mod->gpl_syms));
204 return ks->value;
1da177e4
LT		 205 }
206 }
9f28bb7e
GKH		 207 ks = lookup_symbol(name, mod->gpl_future_syms,
208 (mod->gpl_future_syms +
209 mod->num_gpl_future_syms));
210 if (ks) {
211 if (!gplok) {
212 printk(KERN_WARNING "Symbol %s is being used "
213 "by a non-GPL module, which will not "
214 "be allowed in the future\n", name);
215 printk(KERN_WARNING "Please see the file "
216 "Documentation/feature-removal-schedule.txt "
217 "in the kernel source tree for more "
218 "details.\n");
219 }
220 *crc = symversion(mod->gpl_future_crcs,
221 (ks - mod->gpl_future_syms));
222 return ks->value;
223 }
1da177e4
LT		 224 }
225 DEBUGP("Failed to find symbol %s\n", name);
226 return 0;
227}
228
1da177e4
LT		 229/* Search for module by name: must hold module_mutex. */
230static struct module *find_module(const char *name)
231{
232 struct module *mod;
233
234 list_for_each_entry(mod, &modules, list) {
235 if (strcmp(mod->name, name) == 0)
236 return mod;
237 }
238 return NULL;
239}
240
241#ifdef CONFIG_SMP
242/* Number of blocks used and allocated. */
243static unsigned int pcpu_num_used, pcpu_num_allocated;
244/* Size of each block. -ve means used. */
245static int *pcpu_size;
246
247static int split_block(unsigned int i, unsigned short size)
248{
249 /* Reallocation required? */
250 if (pcpu_num_used + 1 > pcpu_num_allocated) {
251 int *new = kmalloc(sizeof(new[0]) * pcpu_num_allocated*2,
252 GFP_KERNEL);
253 if (!new)
254 return 0;
255
256 memcpy(new, pcpu_size, sizeof(new[0])*pcpu_num_allocated);
257 pcpu_num_allocated *= 2;
258 kfree(pcpu_size);
259 pcpu_size = new;
260 }
261
262 /* Insert a new subblock */
263 memmove(&pcpu_size[i+1], &pcpu_size[i],
264 sizeof(pcpu_size[0]) * (pcpu_num_used - i));
265 pcpu_num_used++;
266
267 pcpu_size[i+1] -= size;
268 pcpu_size[i] = size;
269 return 1;
270}
271
272static inline unsigned int block_size(int val)
273{
274 if (val < 0)
275 return -val;
276 return val;
277}
278
279/* Created by linker magic */
280extern char __per_cpu_start[], __per_cpu_end[];
281
842bbaaa
RR		 282static void *percpu_modalloc(unsigned long size, unsigned long align,
283 const char *name)
1da177e4
LT		 284{
285 unsigned long extra;
286 unsigned int i;
287 void *ptr;
288
842bbaaa
RR		 289 if (align > SMP_CACHE_BYTES) {
290 printk(KERN_WARNING "%s: per-cpu alignment %li > %i\n",
291 name, align, SMP_CACHE_BYTES);
292 align = SMP_CACHE_BYTES;
293 }
1da177e4
LT		 294
295 ptr = __per_cpu_start;
296 for (i = 0; i < pcpu_num_used; ptr += block_size(pcpu_size[i]), i++) {
297 /* Extra for alignment requirement. */
298 extra = ALIGN((unsigned long)ptr, align) - (unsigned long)ptr;
299 BUG_ON(i == 0 && extra != 0);
300
301 if (pcpu_size[i] < 0 || pcpu_size[i] < extra + size)
302 continue;
303
304 /* Transfer extra to previous block. */
305 if (pcpu_size[i-1] < 0)
306 pcpu_size[i-1] -= extra;
307 else
308 pcpu_size[i-1] += extra;
309 pcpu_size[i] -= extra;
310 ptr += extra;
311
312 /* Split block if warranted */
313 if (pcpu_size[i] - size > sizeof(unsigned long))
314 if (!split_block(i, size))
315 return NULL;
316
317 /* Mark allocated */
318 pcpu_size[i] = -pcpu_size[i];
319 return ptr;
320 }
321
322 printk(KERN_WARNING "Could not allocate %lu bytes percpu data\n",
323 size);
324 return NULL;
325}
326
327static void percpu_modfree(void *freeme)
328{
329 unsigned int i;
330 void *ptr = __per_cpu_start + block_size(pcpu_size[0]);
331
332 /* First entry is core kernel percpu data. */
333 for (i = 1; i < pcpu_num_used; ptr += block_size(pcpu_size[i]), i++) {
334 if (ptr == freeme) {
335 pcpu_size[i] = -pcpu_size[i];
336 goto free;
337 }
338 }
339 BUG();
340
341 free:
342 /* Merge with previous? */
343 if (pcpu_size[i-1] >= 0) {
344 pcpu_size[i-1] += pcpu_size[i];
345 pcpu_num_used--;
346 memmove(&pcpu_size[i], &pcpu_size[i+1],
347 (pcpu_num_used - i) * sizeof(pcpu_size[0]));
348 i--;
349 }
350 /* Merge with next? */
351 if (i+1 < pcpu_num_used && pcpu_size[i+1] >= 0) {
352 pcpu_size[i] += pcpu_size[i+1];
353 pcpu_num_used--;
354 memmove(&pcpu_size[i+1], &pcpu_size[i+2],
355 (pcpu_num_used - (i+1)) * sizeof(pcpu_size[0]));
356 }
357}
358
359static unsigned int find_pcpusec(Elf_Ehdr *hdr,
360 Elf_Shdr *sechdrs,
361 const char *secstrings)
362{
363 return find_sec(hdr, sechdrs, secstrings, ".data.percpu");
364}
365
366static int percpu_modinit(void)
367{
368 pcpu_num_used = 2;
369 pcpu_num_allocated = 2;
370 pcpu_size = kmalloc(sizeof(pcpu_size[0]) * pcpu_num_allocated,
371 GFP_KERNEL);
372 /* Static in-kernel percpu data (used). */
373 pcpu_size[0] = -ALIGN(__per_cpu_end-__per_cpu_start, SMP_CACHE_BYTES);
374 /* Free room. */
375 pcpu_size[1] = PERCPU_ENOUGH_ROOM + pcpu_size[0];
376 if (pcpu_size[1] < 0) {
377 printk(KERN_ERR "No per-cpu room for modules.\n");
378 pcpu_num_used = 1;
379 }
380
381 return 0;
382}
383__initcall(percpu_modinit);
384#else /* ... !CONFIG_SMP */
842bbaaa
RR		 385static inline void *percpu_modalloc(unsigned long size, unsigned long align,
386 const char *name)
1da177e4
LT		 387{
388 return NULL;
389}
390static inline void percpu_modfree(void *pcpuptr)
391{
392 BUG();
393}
394static inline unsigned int find_pcpusec(Elf_Ehdr *hdr,
395 Elf_Shdr *sechdrs,
396 const char *secstrings)
397{
398 return 0;
399}
400static inline void percpu_modcopy(void *pcpudst, const void *src,
401 unsigned long size)
402{
403 /* pcpusec should be 0, and size of that section should be 0. */
404 BUG_ON(size != 0);
405}
406#endif /* CONFIG_SMP */
407
c988d2b2
MD		 408#define MODINFO_ATTR(field) \
409static void setup_modinfo_##field(struct module *mod, const char *s) \
410{ \
411 mod->field = kstrdup(s, GFP_KERNEL); \
412} \
413static ssize_t show_modinfo_##field(struct module_attribute *mattr, \
414 struct module *mod, char *buffer) \
415{ \
416 return sprintf(buffer, "%s\n", mod->field); \
417} \
418static int modinfo_##field##_exists(struct module *mod) \
419{ \
420 return mod->field != NULL; \
421} \
422static void free_modinfo_##field(struct module *mod) \
423{ \
424 kfree(mod->field); \
425 mod->field = NULL; \
426} \
427static struct module_attribute modinfo_##field = { \
428 .attr = { .name = __stringify(field), .mode = 0444, \
429 .owner = THIS_MODULE }, \
430 .show = show_modinfo_##field, \
431 .setup = setup_modinfo_##field, \
432 .test = modinfo_##field##_exists, \
433 .free = free_modinfo_##field, \
434};
435
436MODINFO_ATTR(version);
437MODINFO_ATTR(srcversion);
438
03e88ae1 439#ifdef CONFIG_MODULE_UNLOAD
1da177e4
LT		 440/* Init the unload section of the module. */
441static void module_unload_init(struct module *mod)
442{
443 unsigned int i;
444
445 INIT_LIST_HEAD(&mod->modules_which_use_me);
446 for (i = 0; i < NR_CPUS; i++)
447 local_set(&mod->ref[i].count, 0);
448 /* Hold reference count during initialization. */
39c715b7 449 local_set(&mod->ref[raw_smp_processor_id()].count, 1);
1da177e4
LT		 450 /* Backwards compatibility macros put refcount during init. */
451 mod->waiter = current;
452}
453
454/* modules using other modules */
455struct module_use
456{
457 struct list_head list;
458 struct module *module_which_uses;
459};
460
461/* Does a already use b? */
462static int already_uses(struct module *a, struct module *b)
463{
464 struct module_use *use;
465
466 list_for_each_entry(use, &b->modules_which_use_me, list) {
467 if (use->module_which_uses == a) {
468 DEBUGP("%s uses %s!\n", a->name, b->name);
469 return 1;
470 }
471 }
472 DEBUGP("%s does not use %s!\n", a->name, b->name);
473 return 0;
474}
475
476/* Module a uses b */
477static int use_module(struct module *a, struct module *b)
478{
479 struct module_use *use;
480 if (b == NULL || already_uses(a, b)) return 1;
481
482 if (!strong_try_module_get(b))
483 return 0;
484
485 DEBUGP("Allocating new usage for %s.\n", a->name);
486 use = kmalloc(sizeof(*use), GFP_ATOMIC);
487 if (!use) {
488 printk("%s: out of memory loading\n", a->name);
489 module_put(b);
490 return 0;
491 }
492
493 use->module_which_uses = a;
494 list_add(&use->list, &b->modules_which_use_me);
495 return 1;
496}
497
498/* Clear the unload stuff of the module. */
499static void module_unload_free(struct module *mod)
500{
501 struct module *i;
502
503 list_for_each_entry(i, &modules, list) {
504 struct module_use *use;
505
506 list_for_each_entry(use, &i->modules_which_use_me, list) {
507 if (use->module_which_uses == mod) {
508 DEBUGP("%s unusing %s\n", mod->name, i->name);
509 module_put(i);
510 list_del(&use->list);
511 kfree(use);
512 /* There can be at most one match. */
513 break;
514 }
515 }
516 }
517}
518
519#ifdef CONFIG_MODULE_FORCE_UNLOAD
fb169793 520static inline int try_force_unload(unsigned int flags)
1da177e4
LT		 521{
522 int ret = (flags & O_TRUNC);
523 if (ret)
fb169793 524 add_taint(TAINT_FORCED_RMMOD);
1da177e4
LT		 525 return ret;
526}
527#else
fb169793 528static inline int try_force_unload(unsigned int flags)
1da177e4
LT		 529{
530 return 0;
531}
532#endif /* CONFIG_MODULE_FORCE_UNLOAD */
533
534struct stopref
535{
536 struct module *mod;
537 int flags;
538 int *forced;
539};
540
541/* Whole machine is stopped with interrupts off when this runs. */
542static int __try_stop_module(void *_sref)
543{
544 struct stopref *sref = _sref;
545
546 /* If it's not unused, quit unless we are told to block. */
547 if ((sref->flags & O_NONBLOCK) && module_refcount(sref->mod) != 0) {
fb169793 548 if (!(*sref->forced = try_force_unload(sref->flags)))
1da177e4
LT		 549 return -EWOULDBLOCK;
550 }
551
552 /* Mark it as dying. */
553 sref->mod->state = MODULE_STATE_GOING;
554 return 0;
555}
556
557static int try_stop_module(struct module *mod, int flags, int *forced)
558{
559 struct stopref sref = { mod, flags, forced };
560
561 return stop_machine_run(__try_stop_module, &sref, NR_CPUS);
562}
563
564unsigned int module_refcount(struct module *mod)
565{
566 unsigned int i, total = 0;
567
568 for (i = 0; i < NR_CPUS; i++)
569 total += local_read(&mod->ref[i].count);
570 return total;
571}
572EXPORT_SYMBOL(module_refcount);
573
574/* This exists whether we can unload or not */
575static void free_module(struct module *mod);
576
577static void wait_for_zero_refcount(struct module *mod)
578{
579 /* Since we might sleep for some time, drop the semaphore first */
6389a385 580 mutex_unlock(&module_mutex);
1da177e4
LT		 581 for (;;) {
582 DEBUGP("Looking at refcount...\n");
583 set_current_state(TASK_UNINTERRUPTIBLE);
584 if (module_refcount(mod) == 0)
585 break;
586 schedule();
587 }
588 current->state = TASK_RUNNING;
6389a385 589 mutex_lock(&module_mutex);
1da177e4
LT		 590}
591
592asmlinkage long
593sys_delete_module(const char __user *name_user, unsigned int flags)
594{
595 struct module *mod;
596 char name[MODULE_NAME_LEN];
597 int ret, forced = 0;
598
599 if (!capable(CAP_SYS_MODULE))
600 return -EPERM;
601
602 if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
603 return -EFAULT;
604 name[MODULE_NAME_LEN-1] = '\0';
605
6389a385 606 if (mutex_lock_interruptible(&module_mutex) != 0)
1da177e4
LT		 607 return -EINTR;
608
609 mod = find_module(name);
610 if (!mod) {
611 ret = -ENOENT;
612 goto out;
613 }
614
615 if (!list_empty(&mod->modules_which_use_me)) {
616 /* Other modules depend on us: get rid of them first. */
617 ret = -EWOULDBLOCK;
618 goto out;
619 }
620
621 /* Doing init or already dying? */
622 if (mod->state != MODULE_STATE_LIVE) {
623 /* FIXME: if (force), slam module count and wake up
624 waiter --RR */
625 DEBUGP("%s already dying\n", mod->name);
626 ret = -EBUSY;
627 goto out;
628 }
629
630 /* If it has an init func, it must have an exit func to unload */
631 if ((mod->init != NULL && mod->exit == NULL)
632 || mod->unsafe) {
fb169793 633 forced = try_force_unload(flags);
1da177e4
LT		 634 if (!forced) {
635 /* This module can't be removed */
636 ret = -EBUSY;
637 goto out;
638 }
639 }
640
641 /* Set this up before setting mod->state */
642 mod->waiter = current;
643
644 /* Stop the machine so refcounts can't move and disable module. */
645 ret = try_stop_module(mod, flags, &forced);
646 if (ret != 0)
647 goto out;
648
649 /* Never wait if forced. */
650 if (!forced && module_refcount(mod) != 0)
651 wait_for_zero_refcount(mod);
652
653 /* Final destruction now noone is using it. */
654 if (mod->exit != NULL) {
6389a385 655 mutex_unlock(&module_mutex);
1da177e4 656 mod->exit();
6389a385 657 mutex_lock(&module_mutex);
1da177e4
LT		 658 }
659 free_module(mod);
660
661 out:
6389a385 662 mutex_unlock(&module_mutex);
1da177e4
LT		 663 return ret;
664}
665
666static void print_unload_info(struct seq_file *m, struct module *mod)
667{
668 struct module_use *use;
669 int printed_something = 0;
670
671 seq_printf(m, " %u ", module_refcount(mod));
672
673 /* Always include a trailing , so userspace can differentiate
674 between this and the old multi-field proc format. */
675 list_for_each_entry(use, &mod->modules_which_use_me, list) {
676 printed_something = 1;
677 seq_printf(m, "%s,", use->module_which_uses->name);
678 }
679
680 if (mod->unsafe) {
681 printed_something = 1;
682 seq_printf(m, "[unsafe],");
683 }
684
685 if (mod->init != NULL && mod->exit == NULL) {
686 printed_something = 1;
687 seq_printf(m, "[permanent],");
688 }
689
690 if (!printed_something)
691 seq_printf(m, "-");
692}
693
694void __symbol_put(const char *symbol)
695{
696 struct module *owner;
697 unsigned long flags;
698 const unsigned long *crc;
699
700 spin_lock_irqsave(&modlist_lock, flags);
701 if (!__find_symbol(symbol, &owner, &crc, 1))
702 BUG();
703 module_put(owner);
704 spin_unlock_irqrestore(&modlist_lock, flags);
705}
706EXPORT_SYMBOL(__symbol_put);
707
708void symbol_put_addr(void *addr)
709{
5e376613 710 struct module *modaddr;
1da177e4 711
5e376613
TP		 712 if (core_kernel_text((unsigned long)addr))
713 return;
1da177e4 714
5e376613
TP		 715 if (!(modaddr = module_text_address((unsigned long)addr)))
716 BUG();
717 module_put(modaddr);
1da177e4
LT		 718}
719EXPORT_SYMBOL_GPL(symbol_put_addr);
720
721static ssize_t show_refcnt(struct module_attribute *mattr,
722 struct module *mod, char *buffer)
723{
724 /* sysfs holds a reference */
725 return sprintf(buffer, "%u\n", module_refcount(mod)-1);
726}
727
728static struct module_attribute refcnt = {
729 .attr = { .name = "refcnt", .mode = 0444, .owner = THIS_MODULE },
730 .show = show_refcnt,
731};
732
733#else /* !CONFIG_MODULE_UNLOAD */
734static void print_unload_info(struct seq_file *m, struct module *mod)
735{
736 /* We don't know the usage count, or what modules are using. */
737 seq_printf(m, " - -");
738}
739
740static inline void module_unload_free(struct module *mod)
741{
742}
743
744static inline int use_module(struct module *a, struct module *b)
745{
746 return strong_try_module_get(b);
747}
748
749static inline void module_unload_init(struct module *mod)
750{
751}
752#endif /* CONFIG_MODULE_UNLOAD */
753
03e88ae1
GKH		 754static struct module_attribute *modinfo_attrs[] = {
755 &modinfo_version,
756 &modinfo_srcversion,
757#ifdef CONFIG_MODULE_UNLOAD
758 &refcnt,
759#endif
760 NULL,
761};
762
1da177e4
LT		 763static const char vermagic[] = VERMAGIC_STRING;
764
765#ifdef CONFIG_MODVERSIONS
766static int check_version(Elf_Shdr *sechdrs,
767 unsigned int versindex,
768 const char *symname,
769 struct module *mod,
770 const unsigned long *crc)
771{
772 unsigned int i, num_versions;
773 struct modversion_info *versions;
774
775 /* Exporting module didn't supply crcs? OK, we're already tainted. */
776 if (!crc)
777 return 1;
778
779 versions = (void *) sechdrs[versindex].sh_addr;
780 num_versions = sechdrs[versindex].sh_size
781 / sizeof(struct modversion_info);
782
783 for (i = 0; i < num_versions; i++) {
784 if (strcmp(versions[i].name, symname) != 0)
785 continue;
786
787 if (versions[i].crc == *crc)
788 return 1;
789 printk("%s: disagrees about version of symbol %s\n",
790 mod->name, symname);
791 DEBUGP("Found checksum %lX vs module %lX\n",
792 *crc, versions[i].crc);
793 return 0;
794 }
795 /* Not in module's version table. OK, but that taints the kernel. */
796 if (!(tainted & TAINT_FORCED_MODULE)) {
797 printk("%s: no version for \"%s\" found: kernel tainted.\n",
798 mod->name, symname);
9f158333 799 add_taint(TAINT_FORCED_MODULE);
1da177e4
LT		 800 }
801 return 1;
802}
803
804static inline int check_modstruct_version(Elf_Shdr *sechdrs,
805 unsigned int versindex,
806 struct module *mod)
807{
808 const unsigned long *crc;
809 struct module *owner;
810
811 if (!__find_symbol("struct_module", &owner, &crc, 1))
812 BUG();
813 return check_version(sechdrs, versindex, "struct_module", mod,
814 crc);
815}
816
817/* First part is kernel version, which we ignore. */
818static inline int same_magic(const char *amagic, const char *bmagic)
819{
820 amagic += strcspn(amagic, " ");
821 bmagic += strcspn(bmagic, " ");
822 return strcmp(amagic, bmagic) == 0;
823}
824#else
825static inline int check_version(Elf_Shdr *sechdrs,
826 unsigned int versindex,
827 const char *symname,
828 struct module *mod,
829 const unsigned long *crc)
830{
831 return 1;
832}
833
834static inline int check_modstruct_version(Elf_Shdr *sechdrs,
835 unsigned int versindex,
836 struct module *mod)
837{
838 return 1;
839}
840
841static inline int same_magic(const char *amagic, const char *bmagic)
842{
843 return strcmp(amagic, bmagic) == 0;
844}
845#endif /* CONFIG_MODVERSIONS */
846
847/* Resolve a symbol for this module. I.e. if we find one, record usage.
848 Must be holding module_mutex. */
849static unsigned long resolve_symbol(Elf_Shdr *sechdrs,
850 unsigned int versindex,
851 const char *name,
852 struct module *mod)
853{
854 struct module *owner;
855 unsigned long ret;
856 const unsigned long *crc;
857
1da177e4
LT		 858 ret = __find_symbol(name, &owner, &crc, mod->license_gplok);
859 if (ret) {
860 /* use_module can fail due to OOM, or module unloading */
861 if (!check_version(sechdrs, versindex, name, mod, crc) ||
862 !use_module(mod, owner))
863 ret = 0;
864 }
1da177e4
LT		 865 return ret;
866}
867
868
869/*
870 * /sys/module/foo/sections stuff
871 * J. Corbet <corbet@lwn.net>
872 */
873#ifdef CONFIG_KALLSYMS
874static ssize_t module_sect_show(struct module_attribute *mattr,
875 struct module *mod, char *buf)
876{
877 struct module_sect_attr *sattr =
878 container_of(mattr, struct module_sect_attr, mattr);
879 return sprintf(buf, "0x%lx\n", sattr->address);
880}
881
882static void add_sect_attrs(struct module *mod, unsigned int nsect,
883 char *secstrings, Elf_Shdr *sechdrs)
884{
885 unsigned int nloaded = 0, i, size[2];
886 struct module_sect_attrs *sect_attrs;
887 struct module_sect_attr *sattr;
888 struct attribute **gattr;
889
890 /* Count loaded sections and allocate structures */
891 for (i = 0; i < nsect; i++)
892 if (sechdrs[i].sh_flags & SHF_ALLOC)
893 nloaded++;
894 size[0] = ALIGN(sizeof(*sect_attrs)
895 + nloaded * sizeof(sect_attrs->attrs[0]),
896 sizeof(sect_attrs->grp.attrs[0]));
897 size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]);
898 if (! (sect_attrs = kmalloc(size[0] + size[1], GFP_KERNEL)))
899 return;
900
901 /* Setup section attributes. */
902 sect_attrs->grp.name = "sections";
903 sect_attrs->grp.attrs = (void *)sect_attrs + size[0];
904
905 sattr = &sect_attrs->attrs[0];
906 gattr = &sect_attrs->grp.attrs[0];
907 for (i = 0; i < nsect; i++) {
908 if (! (sechdrs[i].sh_flags & SHF_ALLOC))
909 continue;
910 sattr->address = sechdrs[i].sh_addr;
911 strlcpy(sattr->name, secstrings + sechdrs[i].sh_name,
912 MODULE_SECT_NAME_LEN);
913 sattr->mattr.show = module_sect_show;
914 sattr->mattr.store = NULL;
915 sattr->mattr.attr.name = sattr->name;
916 sattr->mattr.attr.owner = mod;
917 sattr->mattr.attr.mode = S_IRUGO;
918 *(gattr++) = &(sattr++)->mattr.attr;
919 }
920 *gattr = NULL;
921
922 if (sysfs_create_group(&mod->mkobj.kobj, &sect_attrs->grp))
923 goto out;
924
925 mod->sect_attrs = sect_attrs;
926 return;
927 out:
928 kfree(sect_attrs);
929}
930
931static void remove_sect_attrs(struct module *mod)
932{
933 if (mod->sect_attrs) {
934 sysfs_remove_group(&mod->mkobj.kobj,
935 &mod->sect_attrs->grp);
936 /* We are positive that no one is using any sect attrs
937 * at this point. Deallocate immediately. */
938 kfree(mod->sect_attrs);
939 mod->sect_attrs = NULL;
940 }
941}
942
943
944#else
945static inline void add_sect_attrs(struct module *mod, unsigned int nsect,
946 char *sectstrings, Elf_Shdr *sechdrs)
947{
948}
949
950static inline void remove_sect_attrs(struct module *mod)
951{
952}
953#endif /* CONFIG_KALLSYMS */
954
c988d2b2
MD		 955static int module_add_modinfo_attrs(struct module *mod)
956{
957 struct module_attribute *attr;
03e88ae1 958 struct module_attribute *temp_attr;
c988d2b2
MD		 959 int error = 0;
960 int i;
961
03e88ae1
GKH		 962 mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
963 (ARRAY_SIZE(modinfo_attrs) + 1)),
964 GFP_KERNEL);
965 if (!mod->modinfo_attrs)
966 return -ENOMEM;
967
968 temp_attr = mod->modinfo_attrs;
c988d2b2
MD		 969 for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
970 if (!attr->test ||
03e88ae1
GKH		 971 (attr->test && attr->test(mod))) {
972 memcpy(temp_attr, attr, sizeof(*temp_attr));
973 temp_attr->attr.owner = mod;
974 error = sysfs_create_file(&mod->mkobj.kobj,&temp_attr->attr);
975 ++temp_attr;
976 }
c988d2b2
MD		 977 }
978 return error;
979}
980
981static void module_remove_modinfo_attrs(struct module *mod)
982{
983 struct module_attribute *attr;
984 int i;
985
03e88ae1
GKH		 986 for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
987 /* pick a field to test for end of list */
988 if (!attr->attr.name)
989 break;
c988d2b2 990 sysfs_remove_file(&mod->mkobj.kobj,&attr->attr);
03e88ae1
GKH		 991 if (attr->free)
992 attr->free(mod);
c988d2b2 993 }
03e88ae1 994 kfree(mod->modinfo_attrs);
c988d2b2 995}
1da177e4
LT		 996
997static int mod_sysfs_setup(struct module *mod,
998 struct kernel_param *kparam,
999 unsigned int num_params)
1000{
1001 int err;
1002
1003 memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
1004 err = kobject_set_name(&mod->mkobj.kobj, "%s", mod->name);
1005 if (err)
1006 goto out;
1007 kobj_set_kset_s(&mod->mkobj, module_subsys);
1008 mod->mkobj.mod = mod;
1009 err = kobject_register(&mod->mkobj.kobj);
1010 if (err)
1011 goto out;
1012
1da177e4
LT		 1013 err = module_param_sysfs_setup(mod, kparam, num_params);
1014 if (err)
1015 goto out_unreg;
1016
c988d2b2
MD		 1017 err = module_add_modinfo_attrs(mod);
1018 if (err)
1019 goto out_unreg;
c988d2b2 1020
1da177e4
LT		 1021 return 0;
1022
1023out_unreg:
1024 kobject_unregister(&mod->mkobj.kobj);
1025out:
1026 return err;
1027}
1028
1029static void mod_kobject_remove(struct module *mod)
1030{
c988d2b2 1031 module_remove_modinfo_attrs(mod);
1da177e4
LT		 1032 module_param_sysfs_remove(mod);
1033
1034 kobject_unregister(&mod->mkobj.kobj);
1035}
1036
1037/*
1038 * unlink the module with the whole machine is stopped with interrupts off
1039 * - this defends against kallsyms not taking locks
1040 */
1041static int __unlink_module(void *_mod)
1042{
1043 struct module *mod = _mod;
1044 list_del(&mod->list);
1045 return 0;
1046}
1047
1048/* Free a module, remove from lists, etc (must hold module mutex). */
1049static void free_module(struct module *mod)
1050{
1051 /* Delete from various lists */
1052 stop_machine_run(__unlink_module, mod, NR_CPUS);
1053 remove_sect_attrs(mod);
1054 mod_kobject_remove(mod);
1055
4552d5dc
JB		 1056 unwind_remove_table(mod->unwind_info, 0);
1057
1da177e4
LT		 1058 /* Arch-specific cleanup. */
1059 module_arch_cleanup(mod);
1060
1061 /* Module unload stuff */
1062 module_unload_free(mod);
1063
1064 /* This may be NULL, but that's OK */
1065 module_free(mod, mod->module_init);
1066 kfree(mod->args);
1067 if (mod->percpu)
1068 percpu_modfree(mod->percpu);
1069
1070 /* Finally, free the core (containing the module structure) */
1071 module_free(mod, mod->module_core);
1072}
1073
1074void *__symbol_get(const char *symbol)
1075{
1076 struct module *owner;
1077 unsigned long value, flags;
1078 const unsigned long *crc;
1079
1080 spin_lock_irqsave(&modlist_lock, flags);
1081 value = __find_symbol(symbol, &owner, &crc, 1);
1082 if (value && !strong_try_module_get(owner))
1083 value = 0;
1084 spin_unlock_irqrestore(&modlist_lock, flags);
1085
1086 return (void *)value;
1087}
1088EXPORT_SYMBOL_GPL(__symbol_get);
1089
eea8b54d
AN		 1090/*
1091 * Ensure that an exported symbol [global namespace] does not already exist
1092 * in the Kernel or in some other modules exported symbol table.
1093 */
1094static int verify_export_symbols(struct module *mod)
1095{
1096 const char *name = NULL;
1097 unsigned long i, ret = 0;
1098 struct module *owner;
1099 const unsigned long *crc;
1100
1101 for (i = 0; i < mod->num_syms; i++)
1102 if (__find_symbol(mod->syms[i].name, &owner, &crc, 1)) {
1103 name = mod->syms[i].name;
1104 ret = -ENOEXEC;
1105 goto dup;
1106 }
1107
1108 for (i = 0; i < mod->num_gpl_syms; i++)
1109 if (__find_symbol(mod->gpl_syms[i].name, &owner, &crc, 1)) {
1110 name = mod->gpl_syms[i].name;
1111 ret = -ENOEXEC;
1112 goto dup;
1113 }
1114
1115dup:
1116 if (ret)
1117 printk(KERN_ERR "%s: exports duplicate symbol %s (owned by %s)\n",
1118 mod->name, name, module_name(owner));
1119
1120 return ret;
1121}
1122
1da177e4
LT		 1123/* Change all symbols so that sh_value encodes the pointer directly. */
1124static int simplify_symbols(Elf_Shdr *sechdrs,
1125 unsigned int symindex,
1126 const char *strtab,
1127 unsigned int versindex,
1128 unsigned int pcpuindex,
1129 struct module *mod)
1130{
1131 Elf_Sym *sym = (void *)sechdrs[symindex].sh_addr;
1132 unsigned long secbase;
1133 unsigned int i, n = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
1134 int ret = 0;
1135
1136 for (i = 1; i < n; i++) {
1137 switch (sym[i].st_shndx) {
1138 case SHN_COMMON:
1139 /* We compiled with -fno-common. These are not
1140 supposed to happen. */
1141 DEBUGP("Common symbol: %s\n", strtab + sym[i].st_name);
1142 printk("%s: please compile with -fno-common\n",
1143 mod->name);
1144 ret = -ENOEXEC;
1145 break;
1146
1147 case SHN_ABS:
1148 /* Don't need to do anything */
1149 DEBUGP("Absolute symbol: 0x%08lx\n",
1150 (long)sym[i].st_value);
1151 break;
1152
1153 case SHN_UNDEF:
1154 sym[i].st_value
1155 = resolve_symbol(sechdrs, versindex,
1156 strtab + sym[i].st_name, mod);
1157
1158 /* Ok if resolved. */
1159 if (sym[i].st_value != 0)
1160 break;
1161 /* Ok if weak. */
1162 if (ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
1163 break;
1164
1165 printk(KERN_WARNING "%s: Unknown symbol %s\n",
1166 mod->name, strtab + sym[i].st_name);
1167 ret = -ENOENT;
1168 break;
1169
1170 default:
1171 /* Divert to percpu allocation if a percpu var. */
1172 if (sym[i].st_shndx == pcpuindex)
1173 secbase = (unsigned long)mod->percpu;
1174 else
1175 secbase = sechdrs[sym[i].st_shndx].sh_addr;
1176 sym[i].st_value += secbase;
1177 break;
1178 }
1179 }
1180
1181 return ret;
1182}
1183
1184/* Update size with this section: return offset. */
1185static long get_offset(unsigned long *size, Elf_Shdr *sechdr)
1186{
1187 long ret;
1188
1189 ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
1190 *size = ret + sechdr->sh_size;
1191 return ret;
1192}
1193
1194/* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
1195 might -- code, read-only data, read-write data, small data. Tally
1196 sizes, and place the offsets into sh_entsize fields: high bit means it
1197 belongs in init. */
1198static void layout_sections(struct module *mod,
1199 const Elf_Ehdr *hdr,
1200 Elf_Shdr *sechdrs,
1201 const char *secstrings)
1202{
1203 static unsigned long const masks[][2] = {
1204 /* NOTE: all executable code must be the first section
1205 * in this array; otherwise modify the text_size
1206 * finder in the two loops below */
1207 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
1208 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
1209 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
1210 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
1211 };
1212 unsigned int m, i;
1213
1214 for (i = 0; i < hdr->e_shnum; i++)
1215 sechdrs[i].sh_entsize = ~0UL;
1216
1217 DEBUGP("Core section allocation order:\n");
1218 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
1219 for (i = 0; i < hdr->e_shnum; ++i) {
1220 Elf_Shdr *s = &sechdrs[i];
1221
1222 if ((s->sh_flags & masks[m][0]) != masks[m][0]
1223 || (s->sh_flags & masks[m][1])
1224 || s->sh_entsize != ~0UL
1225 || strncmp(secstrings + s->sh_name,
1226 ".init", 5) == 0)
1227 continue;
1228 s->sh_entsize = get_offset(&mod->core_size, s);
1229 DEBUGP("\t%s\n", secstrings + s->sh_name);
1230 }
1231 if (m == 0)
1232 mod->core_text_size = mod->core_size;
1233 }
1234
1235 DEBUGP("Init section allocation order:\n");
1236 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
1237 for (i = 0; i < hdr->e_shnum; ++i) {
1238 Elf_Shdr *s = &sechdrs[i];
1239
1240 if ((s->sh_flags & masks[m][0]) != masks[m][0]
1241 || (s->sh_flags & masks[m][1])
1242 || s->sh_entsize != ~0UL
1243 || strncmp(secstrings + s->sh_name,
1244 ".init", 5) != 0)
1245 continue;
1246 s->sh_entsize = (get_offset(&mod->init_size, s)
1247 | INIT_OFFSET_MASK);
1248 DEBUGP("\t%s\n", secstrings + s->sh_name);
1249 }
1250 if (m == 0)
1251 mod->init_text_size = mod->init_size;
1252 }
1253}
1254
1da177e4
LT		 1255static void set_license(struct module *mod, const char *license)
1256{
1257 if (!license)
1258 license = "unspecified";
1259
1260 mod->license_gplok = license_is_gpl_compatible(license);
1261 if (!mod->license_gplok && !(tainted & TAINT_PROPRIETARY_MODULE)) {
1262 printk(KERN_WARNING "%s: module license '%s' taints kernel.\n",
1263 mod->name, license);
9f158333 1264 add_taint(TAINT_PROPRIETARY_MODULE);
1da177e4
LT		 1265 }
1266}
1267
1268/* Parse tag=value strings from .modinfo section */
1269static char *next_string(char *string, unsigned long *secsize)
1270{
1271 /* Skip non-zero chars */
1272 while (string[0]) {
1273 string++;
1274 if ((*secsize)-- <= 1)
1275 return NULL;
1276 }
1277
1278 /* Skip any zero padding. */
1279 while (!string[0]) {
1280 string++;
1281 if ((*secsize)-- <= 1)
1282 return NULL;
1283 }
1284 return string;
1285}
1286
1287static char *get_modinfo(Elf_Shdr *sechdrs,
1288 unsigned int info,
1289 const char *tag)
1290{
1291 char *p;
1292 unsigned int taglen = strlen(tag);
1293 unsigned long size = sechdrs[info].sh_size;
1294
1295 for (p = (char *)sechdrs[info].sh_addr; p; p = next_string(p, &size)) {
1296 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
1297 return p + taglen + 1;
1298 }
1299 return NULL;
1300}
1301
c988d2b2
MD		 1302static void setup_modinfo(struct module *mod, Elf_Shdr *sechdrs,
1303 unsigned int infoindex)
1304{
1305 struct module_attribute *attr;
1306 int i;
1307
1308 for (i = 0; (attr = modinfo_attrs[i]); i++) {
1309 if (attr->setup)
1310 attr->setup(mod,
1311 get_modinfo(sechdrs,
1312 infoindex,
1313 attr->attr.name));
1314 }
1315}
c988d2b2 1316
1da177e4
LT		 1317#ifdef CONFIG_KALLSYMS
1318int is_exported(const char *name, const struct module *mod)
1319{
3fd6805f
SR		 1320 if (!mod && lookup_symbol(name, __start___ksymtab, __stop___ksymtab))
1321 return 1;
1322 else
f867d2a2 1323 if (mod && lookup_symbol(name, mod->syms, mod->syms + mod->num_syms))
1da177e4 1324 return 1;
3fd6805f
SR		 1325 else
1326 return 0;
1da177e4
LT		 1327}
1328
1329/* As per nm */
1330static char elf_type(const Elf_Sym *sym,
1331 Elf_Shdr *sechdrs,
1332 const char *secstrings,
1333 struct module *mod)
1334{
1335 if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
1336 if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
1337 return 'v';
1338 else
1339 return 'w';
1340 }
1341 if (sym->st_shndx == SHN_UNDEF)
1342 return 'U';
1343 if (sym->st_shndx == SHN_ABS)
1344 return 'a';
1345 if (sym->st_shndx >= SHN_LORESERVE)
1346 return '?';
1347 if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
1348 return 't';
1349 if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
1350 && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
1351 if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
1352 return 'r';
1353 else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
1354 return 'g';
1355 else
1356 return 'd';
1357 }
1358 if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
1359 if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
1360 return 's';
1361 else
1362 return 'b';
1363 }
1364 if (strncmp(secstrings + sechdrs[sym->st_shndx].sh_name,
1365 ".debug", strlen(".debug")) == 0)
1366 return 'n';
1367 return '?';
1368}
1369
1370static void add_kallsyms(struct module *mod,
1371 Elf_Shdr *sechdrs,
1372 unsigned int symindex,
1373 unsigned int strindex,
1374 const char *secstrings)
1375{
1376 unsigned int i;
1377
1378 mod->symtab = (void *)sechdrs[symindex].sh_addr;
1379 mod->num_symtab = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
1380 mod->strtab = (void *)sechdrs[strindex].sh_addr;
1381
1382 /* Set types up while we still have access to sections. */
1383 for (i = 0; i < mod->num_symtab; i++)
1384 mod->symtab[i].st_info
1385 = elf_type(&mod->symtab[i], sechdrs, secstrings, mod);
1386}
1387#else
1388static inline void add_kallsyms(struct module *mod,
1389 Elf_Shdr *sechdrs,
1390 unsigned int symindex,
1391 unsigned int strindex,
1392 const char *secstrings)
1393{
1394}
1395#endif /* CONFIG_KALLSYMS */
1396
1397/* Allocate and load the module: note that size of section 0 is always
1398 zero, and we rely on this for optional sections. */
1399static struct module *load_module(void __user *umod,
1400 unsigned long len,
1401 const char __user *uargs)
1402{
1403 Elf_Ehdr *hdr;
1404 Elf_Shdr *sechdrs;
1405 char *secstrings, *args, *modmagic, *strtab = NULL;
1406 unsigned int i, symindex = 0, strindex = 0, setupindex, exindex,
1407 exportindex, modindex, obsparmindex, infoindex, gplindex,
9f28bb7e 1408 crcindex, gplcrcindex, versindex, pcpuindex, gplfutureindex,
4552d5dc 1409 gplfuturecrcindex, unwindex = 0;
1da177e4
LT		 1410 struct module *mod;
1411 long err = 0;
1412 void *percpu = NULL, *ptr = NULL; /* Stops spurious gcc warning */
1413 struct exception_table_entry *extable;
378bac82 1414 mm_segment_t old_fs;
1da177e4
LT		 1415
1416 DEBUGP("load_module: umod=%p, len=%lu, uargs=%p\n",
1417 umod, len, uargs);
1418 if (len < sizeof(*hdr))
1419 return ERR_PTR(-ENOEXEC);
1420
1421 /* Suck in entire file: we'll want most of it. */
1422 /* vmalloc barfs on "unusual" numbers. Check here */
1423 if (len > 64 * 1024 * 1024 || (hdr = vmalloc(len)) == NULL)
1424 return ERR_PTR(-ENOMEM);
1425 if (copy_from_user(hdr, umod, len) != 0) {
1426 err = -EFAULT;
1427 goto free_hdr;
1428 }
1429
1430 /* Sanity checks against insmoding binaries or wrong arch,
1431 weird elf version */
1432 if (memcmp(hdr->e_ident, ELFMAG, 4) != 0
1433 || hdr->e_type != ET_REL
1434 || !elf_check_arch(hdr)
1435 || hdr->e_shentsize != sizeof(*sechdrs)) {
1436 err = -ENOEXEC;
1437 goto free_hdr;
1438 }
1439
1440 if (len < hdr->e_shoff + hdr->e_shnum * sizeof(Elf_Shdr))
1441 goto truncated;
1442
1443 /* Convenience variables */
1444 sechdrs = (void *)hdr + hdr->e_shoff;
1445 secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
1446 sechdrs[0].sh_addr = 0;
1447
1448 for (i = 1; i < hdr->e_shnum; i++) {
1449 if (sechdrs[i].sh_type != SHT_NOBITS
1450 && len < sechdrs[i].sh_offset + sechdrs[i].sh_size)
1451 goto truncated;
1452
1453 /* Mark all sections sh_addr with their address in the
1454 temporary image. */
1455 sechdrs[i].sh_addr = (size_t)hdr + sechdrs[i].sh_offset;
1456
1457 /* Internal symbols and strings. */
1458 if (sechdrs[i].sh_type == SHT_SYMTAB) {
1459 symindex = i;
1460 strindex = sechdrs[i].sh_link;
1461 strtab = (char *)hdr + sechdrs[strindex].sh_offset;
1462 }
1463#ifndef CONFIG_MODULE_UNLOAD
1464 /* Don't load .exit sections */
1465 if (strncmp(secstrings+sechdrs[i].sh_name, ".exit", 5) == 0)
1466 sechdrs[i].sh_flags &= ~(unsigned long)SHF_ALLOC;
1467#endif
1468 }
1469
1470 modindex = find_sec(hdr, sechdrs, secstrings,
1471 ".gnu.linkonce.this_module");
1472 if (!modindex) {
1473 printk(KERN_WARNING "No module found in object\n");
1474 err = -ENOEXEC;
1475 goto free_hdr;
1476 }
1477 mod = (void *)sechdrs[modindex].sh_addr;
1478
1479 if (symindex == 0) {
1480 printk(KERN_WARNING "%s: module has no symbols (stripped?)\n",
1481 mod->name);
1482 err = -ENOEXEC;
1483 goto free_hdr;
1484 }
1485
1486 /* Optional sections */
1487 exportindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab");
1488 gplindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_gpl");
9f28bb7e 1489 gplfutureindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_gpl_future");
1da177e4
LT		 1490 crcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab");
1491 gplcrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_gpl");
9f28bb7e 1492 gplfuturecrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_gpl_future");
1da177e4
LT		 1493 setupindex = find_sec(hdr, sechdrs, secstrings, "__param");
1494 exindex = find_sec(hdr, sechdrs, secstrings, "__ex_table");
1495 obsparmindex = find_sec(hdr, sechdrs, secstrings, "__obsparm");
1496 versindex = find_sec(hdr, sechdrs, secstrings, "__versions");
1497 infoindex = find_sec(hdr, sechdrs, secstrings, ".modinfo");
1498 pcpuindex = find_pcpusec(hdr, sechdrs, secstrings);
4552d5dc
JB		 1499#ifdef ARCH_UNWIND_SECTION_NAME
1500 unwindex = find_sec(hdr, sechdrs, secstrings, ARCH_UNWIND_SECTION_NAME);
1501#endif
1da177e4
LT		 1502
1503 /* Don't keep modinfo section */
1504 sechdrs[infoindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
1505#ifdef CONFIG_KALLSYMS
1506 /* Keep symbol and string tables for decoding later. */
1507 sechdrs[symindex].sh_flags |= SHF_ALLOC;
1508 sechdrs[strindex].sh_flags |= SHF_ALLOC;
1509#endif
4552d5dc
JB		 1510 if (unwindex)
1511 sechdrs[unwindex].sh_flags |= SHF_ALLOC;
1da177e4
LT		 1512
1513 /* Check module struct version now, before we try to use module. */
1514 if (!check_modstruct_version(sechdrs, versindex, mod)) {
1515 err = -ENOEXEC;
1516 goto free_hdr;
1517 }
1518
1519 modmagic = get_modinfo(sechdrs, infoindex, "vermagic");
1520 /* This is allowed: modprobe --force will invalidate it. */
1521 if (!modmagic) {
9f158333 1522 add_taint(TAINT_FORCED_MODULE);
1da177e4
LT		 1523 printk(KERN_WARNING "%s: no version magic, tainting kernel.\n",
1524 mod->name);
1525 } else if (!same_magic(modmagic, vermagic)) {
1526 printk(KERN_ERR "%s: version magic '%s' should be '%s'\n",
1527 mod->name, modmagic, vermagic);
1528 err = -ENOEXEC;
1529 goto free_hdr;
1530 }
1531
1532 /* Now copy in args */
24277dda
DA		 1533 args = strndup_user(uargs, ~0UL >> 1);
1534 if (IS_ERR(args)) {
1535 err = PTR_ERR(args);
1da177e4
LT		 1536 goto free_hdr;
1537 }
8e08b756 1538
1da177e4
LT		 1539 if (find_module(mod->name)) {
1540 err = -EEXIST;
1541 goto free_mod;
1542 }
1543
1544 mod->state = MODULE_STATE_COMING;
1545
1546 /* Allow arches to frob section contents and sizes. */
1547 err = module_frob_arch_sections(hdr, sechdrs, secstrings, mod);
1548 if (err < 0)
1549 goto free_mod;
1550
1551 if (pcpuindex) {
1552 /* We have a special allocation for this section. */
1553 percpu = percpu_modalloc(sechdrs[pcpuindex].sh_size,
842bbaaa
RR		 1554 sechdrs[pcpuindex].sh_addralign,
1555 mod->name);
1da177e4
LT		 1556 if (!percpu) {
1557 err = -ENOMEM;
1558 goto free_mod;
1559 }
1560 sechdrs[pcpuindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
1561 mod->percpu = percpu;
1562 }
1563
1564 /* Determine total sizes, and put offsets in sh_entsize. For now
1565 this is done generically; there doesn't appear to be any
1566 special cases for the architectures. */
1567 layout_sections(mod, hdr, sechdrs, secstrings);
1568
1569 /* Do the allocs. */
1570 ptr = module_alloc(mod->core_size);
1571 if (!ptr) {
1572 err = -ENOMEM;
1573 goto free_percpu;
1574 }
1575 memset(ptr, 0, mod->core_size);
1576 mod->module_core = ptr;
1577
1578 ptr = module_alloc(mod->init_size);
1579 if (!ptr && mod->init_size) {
1580 err = -ENOMEM;
1581 goto free_core;
1582 }
1583 memset(ptr, 0, mod->init_size);
1584 mod->module_init = ptr;
1585
1586 /* Transfer each section which specifies SHF_ALLOC */
1587 DEBUGP("final section addresses:\n");
1588 for (i = 0; i < hdr->e_shnum; i++) {
1589 void *dest;
1590
1591 if (!(sechdrs[i].sh_flags & SHF_ALLOC))
1592 continue;
1593
1594 if (sechdrs[i].sh_entsize & INIT_OFFSET_MASK)
1595 dest = mod->module_init
1596 + (sechdrs[i].sh_entsize & ~INIT_OFFSET_MASK);
1597 else
1598 dest = mod->module_core + sechdrs[i].sh_entsize;
1599
1600 if (sechdrs[i].sh_type != SHT_NOBITS)
1601 memcpy(dest, (void *)sechdrs[i].sh_addr,
1602 sechdrs[i].sh_size);
1603 /* Update sh_addr to point to copy in image. */
1604 sechdrs[i].sh_addr = (unsigned long)dest;
1605 DEBUGP("\t0x%lx %s\n", sechdrs[i].sh_addr, secstrings + sechdrs[i].sh_name);
1606 }
1607 /* Module has been moved. */
1608 mod = (void *)sechdrs[modindex].sh_addr;
1609
1610 /* Now we've moved module, initialize linked lists, etc. */
1611 module_unload_init(mod);
1612
1613 /* Set up license info based on the info section */
1614 set_license(mod, get_modinfo(sechdrs, infoindex, "license"));
1615
9841d61d
DJ		 1616 if (strcmp(mod->name, "ndiswrapper") == 0)
1617 add_taint(TAINT_PROPRIETARY_MODULE);
1618 if (strcmp(mod->name, "driverloader") == 0)
1619 add_taint(TAINT_PROPRIETARY_MODULE);
1620
c988d2b2
MD		 1621 /* Set up MODINFO_ATTR fields */
1622 setup_modinfo(mod, sechdrs, infoindex);
c988d2b2 1623
1da177e4
LT		 1624 /* Fix up syms, so that st_value is a pointer to location. */
1625 err = simplify_symbols(sechdrs, symindex, strtab, versindex, pcpuindex,
1626 mod);
1627 if (err < 0)
1628 goto cleanup;
1629
1630 /* Set up EXPORTed & EXPORT_GPLed symbols (section 0 is 0 length) */
1631 mod->num_syms = sechdrs[exportindex].sh_size / sizeof(*mod->syms);
1632 mod->syms = (void *)sechdrs[exportindex].sh_addr;
1633 if (crcindex)
1634 mod->crcs = (void *)sechdrs[crcindex].sh_addr;
1635 mod->num_gpl_syms = sechdrs[gplindex].sh_size / sizeof(*mod->gpl_syms);
1636 mod->gpl_syms = (void *)sechdrs[gplindex].sh_addr;
1637 if (gplcrcindex)
1638 mod->gpl_crcs = (void *)sechdrs[gplcrcindex].sh_addr;
9f28bb7e
GKH		 1639 mod->num_gpl_future_syms = sechdrs[gplfutureindex].sh_size /
1640 sizeof(*mod->gpl_future_syms);
1641 mod->gpl_future_syms = (void *)sechdrs[gplfutureindex].sh_addr;
1642 if (gplfuturecrcindex)
1643 mod->gpl_future_crcs = (void *)sechdrs[gplfuturecrcindex].sh_addr;
1da177e4
LT		 1644
1645#ifdef CONFIG_MODVERSIONS
1646 if ((mod->num_syms && !crcindex) ||
9f28bb7e
GKH		 1647 (mod->num_gpl_syms && !gplcrcindex) ||
1648 (mod->num_gpl_future_syms && !gplfuturecrcindex)) {
1da177e4
LT		 1649 printk(KERN_WARNING "%s: No versions for exported symbols."
1650 " Tainting kernel.\n", mod->name);
9f158333 1651 add_taint(TAINT_FORCED_MODULE);
1da177e4
LT		 1652 }
1653#endif
1654
1655 /* Now do relocations. */
1656 for (i = 1; i < hdr->e_shnum; i++) {
1657 const char *strtab = (char *)sechdrs[strindex].sh_addr;
1658 unsigned int info = sechdrs[i].sh_info;
1659
1660 /* Not a valid relocation section? */
1661 if (info >= hdr->e_shnum)
1662 continue;
1663
1664 /* Don't bother with non-allocated sections */
1665 if (!(sechdrs[info].sh_flags & SHF_ALLOC))
1666 continue;
1667
1668 if (sechdrs[i].sh_type == SHT_REL)
1669 err = apply_relocate(sechdrs, strtab, symindex, i,mod);
1670 else if (sechdrs[i].sh_type == SHT_RELA)
1671 err = apply_relocate_add(sechdrs, strtab, symindex, i,
1672 mod);
1673 if (err < 0)
1674 goto cleanup;
1675 }
1676
eea8b54d
AN		 1677 /* Find duplicate symbols */
1678 err = verify_export_symbols(mod);
1679
1680 if (err < 0)
1681 goto cleanup;
1682
1da177e4
LT		 1683 /* Set up and sort exception table */
1684 mod->num_exentries = sechdrs[exindex].sh_size / sizeof(*mod->extable);
1685 mod->extable = extable = (void *)sechdrs[exindex].sh_addr;
1686 sort_extable(extable, extable + mod->num_exentries);
1687
1688 /* Finally, copy percpu area over. */
1689 percpu_modcopy(mod->percpu, (void *)sechdrs[pcpuindex].sh_addr,
1690 sechdrs[pcpuindex].sh_size);
1691
1692 add_kallsyms(mod, sechdrs, symindex, strindex, secstrings);
1693
1694 err = module_finalize(hdr, sechdrs, mod);
1695 if (err < 0)
1696 goto cleanup;
1697
378bac82
TK		 1698 /* flush the icache in correct context */
1699 old_fs = get_fs();
1700 set_fs(KERNEL_DS);
1701
1702 /*
1703 * Flush the instruction cache, since we've played with text.
1704 * Do it before processing of module parameters, so the module
1705 * can provide parameter accessor functions of its own.
1706 */
1707 if (mod->module_init)
1708 flush_icache_range((unsigned long)mod->module_init,
1709 (unsigned long)mod->module_init
1710 + mod->init_size);
1711 flush_icache_range((unsigned long)mod->module_core,
1712 (unsigned long)mod->module_core + mod->core_size);
1713
1714 set_fs(old_fs);
1715
1da177e4 1716 mod->args = args;
8d3b33f6
RR		 1717 if (obsparmindex)
1718 printk(KERN_WARNING "%s: Ignoring obsolete parameters\n",
1719 mod->name);
1720
1721 /* Size of section 0 is 0, so this works well if no params */
1722 err = parse_args(mod->name, mod->args,
1723 (struct kernel_param *)
1724 sechdrs[setupindex].sh_addr,
1725 sechdrs[setupindex].sh_size
1726 / sizeof(struct kernel_param),
1727 NULL);
1da177e4
LT		 1728 if (err < 0)
1729 goto arch_cleanup;
1730
1731 err = mod_sysfs_setup(mod,
1732 (struct kernel_param *)
1733 sechdrs[setupindex].sh_addr,
1734 sechdrs[setupindex].sh_size
1735 / sizeof(struct kernel_param));
1736 if (err < 0)
1737 goto arch_cleanup;
1738 add_sect_attrs(mod, hdr->e_shnum, secstrings, sechdrs);
1739
4552d5dc
JB		 1740 /* Size of section 0 is 0, so this works well if no unwind info. */
1741 mod->unwind_info = unwind_add_table(mod,
1742 (void *)sechdrs[unwindex].sh_addr,
1743 sechdrs[unwindex].sh_size);
1744
1da177e4
LT		 1745 /* Get rid of temporary copy */
1746 vfree(hdr);
1747
1748 /* Done! */
1749 return mod;
1750
1751 arch_cleanup:
1752 module_arch_cleanup(mod);
1753 cleanup:
1754 module_unload_free(mod);
1755 module_free(mod, mod->module_init);
1756 free_core:
1757 module_free(mod, mod->module_core);
1758 free_percpu:
1759 if (percpu)
1760 percpu_modfree(percpu);
1761 free_mod:
1762 kfree(args);
1763 free_hdr:
1764 vfree(hdr);
6fe2e70b 1765 return ERR_PTR(err);
1da177e4
LT		 1766
1767 truncated:
1768 printk(KERN_ERR "Module len %lu truncated\n", len);
1769 err = -ENOEXEC;
1770 goto free_hdr;
1771}
1772
1773/*
1774 * link the module with the whole machine is stopped with interrupts off
1775 * - this defends against kallsyms not taking locks
1776 */
1777static int __link_module(void *_mod)
1778{
1779 struct module *mod = _mod;
1780 list_add(&mod->list, &modules);
1781 return 0;
1782}
1783
1784/* This is where the real work happens */
1785asmlinkage long
1786sys_init_module(void __user *umod,
1787 unsigned long len,
1788 const char __user *uargs)
1789{
1790 struct module *mod;
1791 int ret = 0;
1792
1793 /* Must have permission */
1794 if (!capable(CAP_SYS_MODULE))
1795 return -EPERM;
1796
1797 /* Only one module load at a time, please */
6389a385 1798 if (mutex_lock_interruptible(&module_mutex) != 0)
1da177e4
LT		 1799 return -EINTR;
1800
1801 /* Do all the hard work */
1802 mod = load_module(umod, len, uargs);
1803 if (IS_ERR(mod)) {
6389a385 1804 mutex_unlock(&module_mutex);
1da177e4
LT		 1805 return PTR_ERR(mod);
1806 }
1807
1da177e4
LT		 1808 /* Now sew it into the lists. They won't access us, since
1809 strong_try_module_get() will fail. */
1810 stop_machine_run(__link_module, mod, NR_CPUS);
1811
1812 /* Drop lock so they can recurse */
6389a385 1813 mutex_unlock(&module_mutex);
1da177e4 1814
e041c683
AS		 1815 blocking_notifier_call_chain(&module_notify_list,
1816 MODULE_STATE_COMING, mod);
1da177e4
LT		 1817
1818 /* Start the module */
1819 if (mod->init != NULL)
1820 ret = mod->init();
1821 if (ret < 0) {
1822 /* Init routine failed: abort. Try to protect us from
1823 buggy refcounters. */
1824 mod->state = MODULE_STATE_GOING;
fbd568a3 1825 synchronize_sched();
1da177e4
LT		 1826 if (mod->unsafe)
1827 printk(KERN_ERR "%s: module is now stuck!\n",
1828 mod->name);
1829 else {
1830 module_put(mod);
6389a385 1831 mutex_lock(&module_mutex);
1da177e4 1832 free_module(mod);
6389a385 1833 mutex_unlock(&module_mutex);
1da177e4
LT		 1834 }
1835 return ret;
1836 }
1837
1838 /* Now it's a first class citizen! */
6389a385 1839 mutex_lock(&module_mutex);
1da177e4
LT		 1840 mod->state = MODULE_STATE_LIVE;
1841 /* Drop initial reference. */
1842 module_put(mod);
4552d5dc 1843 unwind_remove_table(mod->unwind_info, 1);
1da177e4
LT		 1844 module_free(mod, mod->module_init);
1845 mod->module_init = NULL;
1846 mod->init_size = 0;
1847 mod->init_text_size = 0;
6389a385 1848 mutex_unlock(&module_mutex);
1da177e4
LT		 1849
1850 return 0;
1851}
1852
1853static inline int within(unsigned long addr, void *start, unsigned long size)
1854{
1855 return ((void *)addr >= start && (void *)addr < start + size);
1856}
1857
1858#ifdef CONFIG_KALLSYMS
1859/*
1860 * This ignores the intensely annoying "mapping symbols" found
1861 * in ARM ELF files: $a, $t and $d.
1862 */
1863static inline int is_arm_mapping_symbol(const char *str)
1864{
1865 return str[0] == '$' && strchr("atd", str[1])
1866 && (str[2] == '\0' || str[2] == '.');
1867}
1868
1869static const char *get_ksymbol(struct module *mod,
1870 unsigned long addr,
1871 unsigned long *size,
1872 unsigned long *offset)
1873{
1874 unsigned int i, best = 0;
1875 unsigned long nextval;
1876
1877 /* At worse, next value is at end of module */
1878 if (within(addr, mod->module_init, mod->init_size))
1879 nextval = (unsigned long)mod->module_init+mod->init_text_size;
1880 else
1881 nextval = (unsigned long)mod->module_core+mod->core_text_size;
1882
1883 /* Scan for closest preceeding symbol, and next symbol. (ELF
1884 starts real symbols at 1). */
1885 for (i = 1; i < mod->num_symtab; i++) {
1886 if (mod->symtab[i].st_shndx == SHN_UNDEF)
1887 continue;
1888
1889 /* We ignore unnamed symbols: they're uninformative
1890 * and inserted at a whim. */
1891 if (mod->symtab[i].st_value <= addr
1892 && mod->symtab[i].st_value > mod->symtab[best].st_value
1893 && *(mod->strtab + mod->symtab[i].st_name) != '\0'
1894 && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
1895 best = i;
1896 if (mod->symtab[i].st_value > addr
1897 && mod->symtab[i].st_value < nextval
1898 && *(mod->strtab + mod->symtab[i].st_name) != '\0'
1899 && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
1900 nextval = mod->symtab[i].st_value;
1901 }
1902
1903 if (!best)
1904 return NULL;
1905
1906 *size = nextval - mod->symtab[best].st_value;
1907 *offset = addr - mod->symtab[best].st_value;
1908 return mod->strtab + mod->symtab[best].st_name;
1909}
1910
1911/* For kallsyms to ask for address resolution. NULL means not found.
1912 We don't lock, as this is used for oops resolution and races are a
1913 lesser concern. */
1914const char *module_address_lookup(unsigned long addr,
1915 unsigned long *size,
1916 unsigned long *offset,
1917 char **modname)
1918{
1919 struct module *mod;
1920
1921 list_for_each_entry(mod, &modules, list) {
1922 if (within(addr, mod->module_init, mod->init_size)
1923 || within(addr, mod->module_core, mod->core_size)) {
1924 *modname = mod->name;
1925 return get_ksymbol(mod, addr, size, offset);
1926 }
1927 }
1928 return NULL;
1929}
1930
1931struct module *module_get_kallsym(unsigned int symnum,
1932 unsigned long *value,
1933 char *type,
1934 char namebuf[128])
1935{
1936 struct module *mod;
1937
6389a385 1938 mutex_lock(&module_mutex);
1da177e4
LT		 1939 list_for_each_entry(mod, &modules, list) {
1940 if (symnum < mod->num_symtab) {
1941 *value = mod->symtab[symnum].st_value;
1942 *type = mod->symtab[symnum].st_info;
1943 strncpy(namebuf,
1944 mod->strtab + mod->symtab[symnum].st_name,
1945 127);
6389a385 1946 mutex_unlock(&module_mutex);
1da177e4
LT		 1947 return mod;
1948 }
1949 symnum -= mod->num_symtab;
1950 }
6389a385 1951 mutex_unlock(&module_mutex);
1da177e4
LT		 1952 return NULL;
1953}
1954
1955static unsigned long mod_find_symname(struct module *mod, const char *name)
1956{
1957 unsigned int i;
1958
1959 for (i = 0; i < mod->num_symtab; i++)
54e8ce46
KO		 1960 if (strcmp(name, mod->strtab+mod->symtab[i].st_name) == 0 &&
1961 mod->symtab[i].st_info != 'U')
1da177e4
LT		 1962 return mod->symtab[i].st_value;
1963 return 0;
1964}
1965
1966/* Look for this name: can be of form module:name. */
1967unsigned long module_kallsyms_lookup_name(const char *name)
1968{
1969 struct module *mod;
1970 char *colon;
1971 unsigned long ret = 0;
1972
1973 /* Don't lock: we're in enough trouble already. */
1974 if ((colon = strchr(name, ':')) != NULL) {
1975 *colon = '\0';
1976 if ((mod = find_module(name)) != NULL)
1977 ret = mod_find_symname(mod, colon+1);
1978 *colon = ':';
1979 } else {
1980 list_for_each_entry(mod, &modules, list)
1981 if ((ret = mod_find_symname(mod, name)) != 0)
1982 break;
1983 }
1984 return ret;
1985}
1986#endif /* CONFIG_KALLSYMS */
1987
1988/* Called by the /proc file system to return a list of modules. */
1989static void *m_start(struct seq_file *m, loff_t *pos)
1990{
1991 struct list_head *i;
1992 loff_t n = 0;
1993
6389a385 1994 mutex_lock(&module_mutex);
1da177e4
LT		 1995 list_for_each(i, &modules) {
1996 if (n++ == *pos)
1997 break;
1998 }
1999 if (i == &modules)
2000 return NULL;
2001 return i;
2002}
2003
2004static void *m_next(struct seq_file *m, void *p, loff_t *pos)
2005{
2006 struct list_head *i = p;
2007 (*pos)++;
2008 if (i->next == &modules)
2009 return NULL;
2010 return i->next;
2011}
2012
2013static void m_stop(struct seq_file *m, void *p)
2014{
6389a385 2015 mutex_unlock(&module_mutex);
1da177e4
LT		 2016}
2017
2018static int m_show(struct seq_file *m, void *p)
2019{
2020 struct module *mod = list_entry(p, struct module, list);
2021 seq_printf(m, "%s %lu",
2022 mod->name, mod->init_size + mod->core_size);
2023 print_unload_info(m, mod);
2024
2025 /* Informative for users. */
2026 seq_printf(m, " %s",
2027 mod->state == MODULE_STATE_GOING ? "Unloading":
2028 mod->state == MODULE_STATE_COMING ? "Loading":
2029 "Live");
2030 /* Used by oprofile and other similar tools. */
2031 seq_printf(m, " 0x%p", mod->module_core);
2032
2033 seq_printf(m, "\n");
2034 return 0;
2035}
2036
2037/* Format: modulename size refcount deps address
2038
2039 Where refcount is a number or -, and deps is a comma-separated list
2040 of depends or -.
2041*/
2042struct seq_operations modules_op = {
2043 .start = m_start,
2044 .next = m_next,
2045 .stop = m_stop,
2046 .show = m_show
2047};
2048
2049/* Given an address, look for it in the module exception tables. */
2050const struct exception_table_entry *search_module_extables(unsigned long addr)
2051{
2052 unsigned long flags;
2053 const struct exception_table_entry *e = NULL;
2054 struct module *mod;
2055
2056 spin_lock_irqsave(&modlist_lock, flags);
2057 list_for_each_entry(mod, &modules, list) {
2058 if (mod->num_exentries == 0)
2059 continue;
2060
2061 e = search_extable(mod->extable,
2062 mod->extable + mod->num_exentries - 1,
2063 addr);
2064 if (e)
2065 break;
2066 }
2067 spin_unlock_irqrestore(&modlist_lock, flags);
2068
2069 /* Now, if we found one, we are running inside it now, hence
2070 we cannot unload the module, hence no refcnt needed. */
2071 return e;
2072}
2073
2074/* Is this a valid kernel address? We don't grab the lock: we are oopsing. */
2075struct module *__module_text_address(unsigned long addr)
2076{
2077 struct module *mod;
2078
2079 list_for_each_entry(mod, &modules, list)
2080 if (within(addr, mod->module_init, mod->init_text_size)
2081 || within(addr, mod->module_core, mod->core_text_size))
2082 return mod;
2083 return NULL;
2084}
2085
2086struct module *module_text_address(unsigned long addr)
2087{
2088 struct module *mod;
2089 unsigned long flags;
2090
2091 spin_lock_irqsave(&modlist_lock, flags);
2092 mod = __module_text_address(addr);
2093 spin_unlock_irqrestore(&modlist_lock, flags);
2094
2095 return mod;
2096}
2097
2098/* Don't grab lock, we're oopsing. */
2099void print_modules(void)
2100{
2101 struct module *mod;
2102
2103 printk("Modules linked in:");
2104 list_for_each_entry(mod, &modules, list)
2105 printk(" %s", mod->name);
2106 printk("\n");
2107}
2108
2109void module_add_driver(struct module *mod, struct device_driver *drv)
2110{
2111 if (!mod || !drv)
2112 return;
2113
2114 /* Don't check return code; this call is idempotent */
2115 sysfs_create_link(&drv->kobj, &mod->mkobj.kobj, "module");
2116}
2117EXPORT_SYMBOL(module_add_driver);
2118
2119void module_remove_driver(struct device_driver *drv)
2120{
2121 if (!drv)
2122 return;
2123 sysfs_remove_link(&drv->kobj, "module");
2124}
2125EXPORT_SYMBOL(module_remove_driver);
2126
2127#ifdef CONFIG_MODVERSIONS
2128/* Generate the signature for struct module here, too, for modversions. */
2129void struct_module(struct module *mod) { return; }
2130EXPORT_SYMBOL(struct_module);
2131#endif
Linux 6.x block layer and io_uring tree(s)