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-rw-r--r--kernel/module.c2108
1 files changed, 2108 insertions, 0 deletions
diff --git a/kernel/module.c b/kernel/module.c
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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>
23#include <linux/slab.h>
24#include <linux/vmalloc.h>
25#include <linux/elf.h>
26#include <linux/seq_file.h>
27#include <linux/syscalls.h>
28#include <linux/fcntl.h>
29#include <linux/rcupdate.h>
30#include <linux/cpu.h>
31#include <linux/moduleparam.h>
32#include <linux/errno.h>
33#include <linux/err.h>
34#include <linux/vermagic.h>
35#include <linux/notifier.h>
36#include <linux/stop_machine.h>
37#include <linux/device.h>
38#include <asm/uaccess.h>
39#include <asm/semaphore.h>
40#include <asm/cacheflush.h>
41
42#if 0
43#define DEBUGP printk
44#else
45#define DEBUGP(fmt , a...)
46#endif
47
48#ifndef ARCH_SHF_SMALL
49#define ARCH_SHF_SMALL 0
50#endif
51
52/* If this is set, the section belongs in the init part of the module */
53#define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
54
55/* Protects module list */
56static DEFINE_SPINLOCK(modlist_lock);
57
58/* List of modules, protected by module_mutex AND modlist_lock */
59static DECLARE_MUTEX(module_mutex);
60static LIST_HEAD(modules);
61
62static DECLARE_MUTEX(notify_mutex);
63static struct notifier_block * module_notify_list;
64
65int register_module_notifier(struct notifier_block * nb)
66{
67 int err;
68 down(&notify_mutex);
69 err = notifier_chain_register(&module_notify_list, nb);
70 up(&notify_mutex);
71 return err;
72}
73EXPORT_SYMBOL(register_module_notifier);
74
75int unregister_module_notifier(struct notifier_block * nb)
76{
77 int err;
78 down(&notify_mutex);
79 err = notifier_chain_unregister(&module_notify_list, nb);
80 up(&notify_mutex);
81 return err;
82}
83EXPORT_SYMBOL(unregister_module_notifier);
84
85/* We require a truly strong try_module_get() */
86static inline int strong_try_module_get(struct module *mod)
87{
88 if (mod && mod->state == MODULE_STATE_COMING)
89 return 0;
90 return try_module_get(mod);
91}
92
93/* A thread that wants to hold a reference to a module only while it
94 * is running can call ths to safely exit.
95 * nfsd and lockd use this.
96 */
97void __module_put_and_exit(struct module *mod, long code)
98{
99 module_put(mod);
100 do_exit(code);
101}
102EXPORT_SYMBOL(__module_put_and_exit);
103
104/* Find a module section: 0 means not found. */
105static unsigned int find_sec(Elf_Ehdr *hdr,
106 Elf_Shdr *sechdrs,
107 const char *secstrings,
108 const char *name)
109{
110 unsigned int i;
111
112 for (i = 1; i < hdr->e_shnum; i++)
113 /* Alloc bit cleared means "ignore it." */
114 if ((sechdrs[i].sh_flags & SHF_ALLOC)
115 && strcmp(secstrings+sechdrs[i].sh_name, name) == 0)
116 return i;
117 return 0;
118}
119
120/* Provided by the linker */
121extern const struct kernel_symbol __start___ksymtab[];
122extern const struct kernel_symbol __stop___ksymtab[];
123extern const struct kernel_symbol __start___ksymtab_gpl[];
124extern const struct kernel_symbol __stop___ksymtab_gpl[];
125extern const unsigned long __start___kcrctab[];
126extern const unsigned long __start___kcrctab_gpl[];
127
128#ifndef CONFIG_MODVERSIONS
129#define symversion(base, idx) NULL
130#else
131#define symversion(base, idx) ((base) ? ((base) + (idx)) : NULL)
132#endif
133
134/* Find a symbol, return value, crc and module which owns it */
135static unsigned long __find_symbol(const char *name,
136 struct module **owner,
137 const unsigned long **crc,
138 int gplok)
139{
140 struct module *mod;
141 unsigned int i;
142
143 /* Core kernel first. */
144 *owner = NULL;
145 for (i = 0; __start___ksymtab+i < __stop___ksymtab; i++) {
146 if (strcmp(__start___ksymtab[i].name, name) == 0) {
147 *crc = symversion(__start___kcrctab, i);
148 return __start___ksymtab[i].value;
149 }
150 }
151 if (gplok) {
152 for (i = 0; __start___ksymtab_gpl+i<__stop___ksymtab_gpl; i++)
153 if (strcmp(__start___ksymtab_gpl[i].name, name) == 0) {
154 *crc = symversion(__start___kcrctab_gpl, i);
155 return __start___ksymtab_gpl[i].value;
156 }
157 }
158
159 /* Now try modules. */
160 list_for_each_entry(mod, &modules, list) {
161 *owner = mod;
162 for (i = 0; i < mod->num_syms; i++)
163 if (strcmp(mod->syms[i].name, name) == 0) {
164 *crc = symversion(mod->crcs, i);
165 return mod->syms[i].value;
166 }
167
168 if (gplok) {
169 for (i = 0; i < mod->num_gpl_syms; i++) {
170 if (strcmp(mod->gpl_syms[i].name, name) == 0) {
171 *crc = symversion(mod->gpl_crcs, i);
172 return mod->gpl_syms[i].value;
173 }
174 }
175 }
176 }
177 DEBUGP("Failed to find symbol %s\n", name);
178 return 0;
179}
180
181/* Find a symbol in this elf symbol table */
182static unsigned long find_local_symbol(Elf_Shdr *sechdrs,
183 unsigned int symindex,
184 const char *strtab,
185 const char *name)
186{
187 unsigned int i;
188 Elf_Sym *sym = (void *)sechdrs[symindex].sh_addr;
189
190 /* Search (defined) internal symbols first. */
191 for (i = 1; i < sechdrs[symindex].sh_size/sizeof(*sym); i++) {
192 if (sym[i].st_shndx != SHN_UNDEF
193 && strcmp(name, strtab + sym[i].st_name) == 0)
194 return sym[i].st_value;
195 }
196 return 0;
197}
198
199/* Search for module by name: must hold module_mutex. */
200static struct module *find_module(const char *name)
201{
202 struct module *mod;
203
204 list_for_each_entry(mod, &modules, list) {
205 if (strcmp(mod->name, name) == 0)
206 return mod;
207 }
208 return NULL;
209}
210
211#ifdef CONFIG_SMP
212/* Number of blocks used and allocated. */
213static unsigned int pcpu_num_used, pcpu_num_allocated;
214/* Size of each block. -ve means used. */
215static int *pcpu_size;
216
217static int split_block(unsigned int i, unsigned short size)
218{
219 /* Reallocation required? */
220 if (pcpu_num_used + 1 > pcpu_num_allocated) {
221 int *new = kmalloc(sizeof(new[0]) * pcpu_num_allocated*2,
222 GFP_KERNEL);
223 if (!new)
224 return 0;
225
226 memcpy(new, pcpu_size, sizeof(new[0])*pcpu_num_allocated);
227 pcpu_num_allocated *= 2;
228 kfree(pcpu_size);
229 pcpu_size = new;
230 }
231
232 /* Insert a new subblock */
233 memmove(&pcpu_size[i+1], &pcpu_size[i],
234 sizeof(pcpu_size[0]) * (pcpu_num_used - i));
235 pcpu_num_used++;
236
237 pcpu_size[i+1] -= size;
238 pcpu_size[i] = size;
239 return 1;
240}
241
242static inline unsigned int block_size(int val)
243{
244 if (val < 0)
245 return -val;
246 return val;
247}
248
249/* Created by linker magic */
250extern char __per_cpu_start[], __per_cpu_end[];
251
252static void *percpu_modalloc(unsigned long size, unsigned long align)
253{
254 unsigned long extra;
255 unsigned int i;
256 void *ptr;
257
258 BUG_ON(align > SMP_CACHE_BYTES);
259
260 ptr = __per_cpu_start;
261 for (i = 0; i < pcpu_num_used; ptr += block_size(pcpu_size[i]), i++) {
262 /* Extra for alignment requirement. */
263 extra = ALIGN((unsigned long)ptr, align) - (unsigned long)ptr;
264 BUG_ON(i == 0 && extra != 0);
265
266 if (pcpu_size[i] < 0 || pcpu_size[i] < extra + size)
267 continue;
268
269 /* Transfer extra to previous block. */
270 if (pcpu_size[i-1] < 0)
271 pcpu_size[i-1] -= extra;
272 else
273 pcpu_size[i-1] += extra;
274 pcpu_size[i] -= extra;
275 ptr += extra;
276
277 /* Split block if warranted */
278 if (pcpu_size[i] - size > sizeof(unsigned long))
279 if (!split_block(i, size))
280 return NULL;
281
282 /* Mark allocated */
283 pcpu_size[i] = -pcpu_size[i];
284 return ptr;
285 }
286
287 printk(KERN_WARNING "Could not allocate %lu bytes percpu data\n",
288 size);
289 return NULL;
290}
291
292static void percpu_modfree(void *freeme)
293{
294 unsigned int i;
295 void *ptr = __per_cpu_start + block_size(pcpu_size[0]);
296
297 /* First entry is core kernel percpu data. */
298 for (i = 1; i < pcpu_num_used; ptr += block_size(pcpu_size[i]), i++) {
299 if (ptr == freeme) {
300 pcpu_size[i] = -pcpu_size[i];
301 goto free;
302 }
303 }
304 BUG();
305
306 free:
307 /* Merge with previous? */
308 if (pcpu_size[i-1] >= 0) {
309 pcpu_size[i-1] += pcpu_size[i];
310 pcpu_num_used--;
311 memmove(&pcpu_size[i], &pcpu_size[i+1],
312 (pcpu_num_used - i) * sizeof(pcpu_size[0]));
313 i--;
314 }
315 /* Merge with next? */
316 if (i+1 < pcpu_num_used && pcpu_size[i+1] >= 0) {
317 pcpu_size[i] += pcpu_size[i+1];
318 pcpu_num_used--;
319 memmove(&pcpu_size[i+1], &pcpu_size[i+2],
320 (pcpu_num_used - (i+1)) * sizeof(pcpu_size[0]));
321 }
322}
323
324static unsigned int find_pcpusec(Elf_Ehdr *hdr,
325 Elf_Shdr *sechdrs,
326 const char *secstrings)
327{
328 return find_sec(hdr, sechdrs, secstrings, ".data.percpu");
329}
330
331static int percpu_modinit(void)
332{
333 pcpu_num_used = 2;
334 pcpu_num_allocated = 2;
335 pcpu_size = kmalloc(sizeof(pcpu_size[0]) * pcpu_num_allocated,
336 GFP_KERNEL);
337 /* Static in-kernel percpu data (used). */
338 pcpu_size[0] = -ALIGN(__per_cpu_end-__per_cpu_start, SMP_CACHE_BYTES);
339 /* Free room. */
340 pcpu_size[1] = PERCPU_ENOUGH_ROOM + pcpu_size[0];
341 if (pcpu_size[1] < 0) {
342 printk(KERN_ERR "No per-cpu room for modules.\n");
343 pcpu_num_used = 1;
344 }
345
346 return 0;
347}
348__initcall(percpu_modinit);
349#else /* ... !CONFIG_SMP */
350static inline void *percpu_modalloc(unsigned long size, unsigned long align)
351{
352 return NULL;
353}
354static inline void percpu_modfree(void *pcpuptr)
355{
356 BUG();
357}
358static inline unsigned int find_pcpusec(Elf_Ehdr *hdr,
359 Elf_Shdr *sechdrs,
360 const char *secstrings)
361{
362 return 0;
363}
364static inline void percpu_modcopy(void *pcpudst, const void *src,
365 unsigned long size)
366{
367 /* pcpusec should be 0, and size of that section should be 0. */
368 BUG_ON(size != 0);
369}
370#endif /* CONFIG_SMP */
371
372#ifdef CONFIG_MODULE_UNLOAD
373/* Init the unload section of the module. */
374static void module_unload_init(struct module *mod)
375{
376 unsigned int i;
377
378 INIT_LIST_HEAD(&mod->modules_which_use_me);
379 for (i = 0; i < NR_CPUS; i++)
380 local_set(&mod->ref[i].count, 0);
381 /* Hold reference count during initialization. */
382 local_set(&mod->ref[_smp_processor_id()].count, 1);
383 /* Backwards compatibility macros put refcount during init. */
384 mod->waiter = current;
385}
386
387/* modules using other modules */
388struct module_use
389{
390 struct list_head list;
391 struct module *module_which_uses;
392};
393
394/* Does a already use b? */
395static int already_uses(struct module *a, struct module *b)
396{
397 struct module_use *use;
398
399 list_for_each_entry(use, &b->modules_which_use_me, list) {
400 if (use->module_which_uses == a) {
401 DEBUGP("%s uses %s!\n", a->name, b->name);
402 return 1;
403 }
404 }
405 DEBUGP("%s does not use %s!\n", a->name, b->name);
406 return 0;
407}
408
409/* Module a uses b */
410static int use_module(struct module *a, struct module *b)
411{
412 struct module_use *use;
413 if (b == NULL || already_uses(a, b)) return 1;
414
415 if (!strong_try_module_get(b))
416 return 0;
417
418 DEBUGP("Allocating new usage for %s.\n", a->name);
419 use = kmalloc(sizeof(*use), GFP_ATOMIC);
420 if (!use) {
421 printk("%s: out of memory loading\n", a->name);
422 module_put(b);
423 return 0;
424 }
425
426 use->module_which_uses = a;
427 list_add(&use->list, &b->modules_which_use_me);
428 return 1;
429}
430
431/* Clear the unload stuff of the module. */
432static void module_unload_free(struct module *mod)
433{
434 struct module *i;
435
436 list_for_each_entry(i, &modules, list) {
437 struct module_use *use;
438
439 list_for_each_entry(use, &i->modules_which_use_me, list) {
440 if (use->module_which_uses == mod) {
441 DEBUGP("%s unusing %s\n", mod->name, i->name);
442 module_put(i);
443 list_del(&use->list);
444 kfree(use);
445 /* There can be at most one match. */
446 break;
447 }
448 }
449 }
450}
451
452#ifdef CONFIG_MODULE_FORCE_UNLOAD
453static inline int try_force(unsigned int flags)
454{
455 int ret = (flags & O_TRUNC);
456 if (ret)
457 tainted |= TAINT_FORCED_MODULE;
458 return ret;
459}
460#else
461static inline int try_force(unsigned int flags)
462{
463 return 0;
464}
465#endif /* CONFIG_MODULE_FORCE_UNLOAD */
466
467struct stopref
468{
469 struct module *mod;
470 int flags;
471 int *forced;
472};
473
474/* Whole machine is stopped with interrupts off when this runs. */
475static int __try_stop_module(void *_sref)
476{
477 struct stopref *sref = _sref;
478
479 /* If it's not unused, quit unless we are told to block. */
480 if ((sref->flags & O_NONBLOCK) && module_refcount(sref->mod) != 0) {
481 if (!(*sref->forced = try_force(sref->flags)))
482 return -EWOULDBLOCK;
483 }
484
485 /* Mark it as dying. */
486 sref->mod->state = MODULE_STATE_GOING;
487 return 0;
488}
489
490static int try_stop_module(struct module *mod, int flags, int *forced)
491{
492 struct stopref sref = { mod, flags, forced };
493
494 return stop_machine_run(__try_stop_module, &sref, NR_CPUS);
495}
496
497unsigned int module_refcount(struct module *mod)
498{
499 unsigned int i, total = 0;
500
501 for (i = 0; i < NR_CPUS; i++)
502 total += local_read(&mod->ref[i].count);
503 return total;
504}
505EXPORT_SYMBOL(module_refcount);
506
507/* This exists whether we can unload or not */
508static void free_module(struct module *mod);
509
510static void wait_for_zero_refcount(struct module *mod)
511{
512 /* Since we might sleep for some time, drop the semaphore first */
513 up(&module_mutex);
514 for (;;) {
515 DEBUGP("Looking at refcount...\n");
516 set_current_state(TASK_UNINTERRUPTIBLE);
517 if (module_refcount(mod) == 0)
518 break;
519 schedule();
520 }
521 current->state = TASK_RUNNING;
522 down(&module_mutex);
523}
524
525asmlinkage long
526sys_delete_module(const char __user *name_user, unsigned int flags)
527{
528 struct module *mod;
529 char name[MODULE_NAME_LEN];
530 int ret, forced = 0;
531
532 if (!capable(CAP_SYS_MODULE))
533 return -EPERM;
534
535 if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
536 return -EFAULT;
537 name[MODULE_NAME_LEN-1] = '\0';
538
539 if (down_interruptible(&module_mutex) != 0)
540 return -EINTR;
541
542 mod = find_module(name);
543 if (!mod) {
544 ret = -ENOENT;
545 goto out;
546 }
547
548 if (!list_empty(&mod->modules_which_use_me)) {
549 /* Other modules depend on us: get rid of them first. */
550 ret = -EWOULDBLOCK;
551 goto out;
552 }
553
554 /* Doing init or already dying? */
555 if (mod->state != MODULE_STATE_LIVE) {
556 /* FIXME: if (force), slam module count and wake up
557 waiter --RR */
558 DEBUGP("%s already dying\n", mod->name);
559 ret = -EBUSY;
560 goto out;
561 }
562
563 /* If it has an init func, it must have an exit func to unload */
564 if ((mod->init != NULL && mod->exit == NULL)
565 || mod->unsafe) {
566 forced = try_force(flags);
567 if (!forced) {
568 /* This module can't be removed */
569 ret = -EBUSY;
570 goto out;
571 }
572 }
573
574 /* Set this up before setting mod->state */
575 mod->waiter = current;
576
577 /* Stop the machine so refcounts can't move and disable module. */
578 ret = try_stop_module(mod, flags, &forced);
579 if (ret != 0)
580 goto out;
581
582 /* Never wait if forced. */
583 if (!forced && module_refcount(mod) != 0)
584 wait_for_zero_refcount(mod);
585
586 /* Final destruction now noone is using it. */
587 if (mod->exit != NULL) {
588 up(&module_mutex);
589 mod->exit();
590 down(&module_mutex);
591 }
592 free_module(mod);
593
594 out:
595 up(&module_mutex);
596 return ret;
597}
598
599static void print_unload_info(struct seq_file *m, struct module *mod)
600{
601 struct module_use *use;
602 int printed_something = 0;
603
604 seq_printf(m, " %u ", module_refcount(mod));
605
606 /* Always include a trailing , so userspace can differentiate
607 between this and the old multi-field proc format. */
608 list_for_each_entry(use, &mod->modules_which_use_me, list) {
609 printed_something = 1;
610 seq_printf(m, "%s,", use->module_which_uses->name);
611 }
612
613 if (mod->unsafe) {
614 printed_something = 1;
615 seq_printf(m, "[unsafe],");
616 }
617
618 if (mod->init != NULL && mod->exit == NULL) {
619 printed_something = 1;
620 seq_printf(m, "[permanent],");
621 }
622
623 if (!printed_something)
624 seq_printf(m, "-");
625}
626
627void __symbol_put(const char *symbol)
628{
629 struct module *owner;
630 unsigned long flags;
631 const unsigned long *crc;
632
633 spin_lock_irqsave(&modlist_lock, flags);
634 if (!__find_symbol(symbol, &owner, &crc, 1))
635 BUG();
636 module_put(owner);
637 spin_unlock_irqrestore(&modlist_lock, flags);
638}
639EXPORT_SYMBOL(__symbol_put);
640
641void symbol_put_addr(void *addr)
642{
643 unsigned long flags;
644
645 spin_lock_irqsave(&modlist_lock, flags);
646 if (!kernel_text_address((unsigned long)addr))
647 BUG();
648
649 module_put(module_text_address((unsigned long)addr));
650 spin_unlock_irqrestore(&modlist_lock, flags);
651}
652EXPORT_SYMBOL_GPL(symbol_put_addr);
653
654static ssize_t show_refcnt(struct module_attribute *mattr,
655 struct module *mod, char *buffer)
656{
657 /* sysfs holds a reference */
658 return sprintf(buffer, "%u\n", module_refcount(mod)-1);
659}
660
661static struct module_attribute refcnt = {
662 .attr = { .name = "refcnt", .mode = 0444, .owner = THIS_MODULE },
663 .show = show_refcnt,
664};
665
666#else /* !CONFIG_MODULE_UNLOAD */
667static void print_unload_info(struct seq_file *m, struct module *mod)
668{
669 /* We don't know the usage count, or what modules are using. */
670 seq_printf(m, " - -");
671}
672
673static inline void module_unload_free(struct module *mod)
674{
675}
676
677static inline int use_module(struct module *a, struct module *b)
678{
679 return strong_try_module_get(b);
680}
681
682static inline void module_unload_init(struct module *mod)
683{
684}
685#endif /* CONFIG_MODULE_UNLOAD */
686
687#ifdef CONFIG_OBSOLETE_MODPARM
688/* Bounds checking done below */
689static int obsparm_copy_string(const char *val, struct kernel_param *kp)
690{
691 strcpy(kp->arg, val);
692 return 0;
693}
694
695int set_obsolete(const char *val, struct kernel_param *kp)
696{
697 unsigned int min, max;
698 unsigned int size, maxsize;
699 int dummy;
700 char *endp;
701 const char *p;
702 struct obsolete_modparm *obsparm = kp->arg;
703
704 if (!val) {
705 printk(KERN_ERR "Parameter %s needs an argument\n", kp->name);
706 return -EINVAL;
707 }
708
709 /* type is: [min[-max]]{b,h,i,l,s} */
710 p = obsparm->type;
711 min = simple_strtol(p, &endp, 10);
712 if (endp == obsparm->type)
713 min = max = 1;
714 else if (*endp == '-') {
715 p = endp+1;
716 max = simple_strtol(p, &endp, 10);
717 } else
718 max = min;
719 switch (*endp) {
720 case 'b':
721 return param_array(kp->name, val, min, max, obsparm->addr,
722 1, param_set_byte, &dummy);
723 case 'h':
724 return param_array(kp->name, val, min, max, obsparm->addr,
725 sizeof(short), param_set_short, &dummy);
726 case 'i':
727 return param_array(kp->name, val, min, max, obsparm->addr,
728 sizeof(int), param_set_int, &dummy);
729 case 'l':
730 return param_array(kp->name, val, min, max, obsparm->addr,
731 sizeof(long), param_set_long, &dummy);
732 case 's':
733 return param_array(kp->name, val, min, max, obsparm->addr,
734 sizeof(char *), param_set_charp, &dummy);
735
736 case 'c':
737 /* Undocumented: 1-5c50 means 1-5 strings of up to 49 chars,
738 and the decl is "char xxx[5][50];" */
739 p = endp+1;
740 maxsize = simple_strtol(p, &endp, 10);
741 /* We check lengths here (yes, this is a hack). */
742 p = val;
743 while (p[size = strcspn(p, ",")]) {
744 if (size >= maxsize)
745 goto oversize;
746 p += size+1;
747 }
748 if (size >= maxsize)
749 goto oversize;
750 return param_array(kp->name, val, min, max, obsparm->addr,
751 maxsize, obsparm_copy_string, &dummy);
752 }
753 printk(KERN_ERR "Unknown obsolete parameter type %s\n", obsparm->type);
754 return -EINVAL;
755 oversize:
756 printk(KERN_ERR
757 "Parameter %s doesn't fit in %u chars.\n", kp->name, maxsize);
758 return -EINVAL;
759}
760
761static int obsolete_params(const char *name,
762 char *args,
763 struct obsolete_modparm obsparm[],
764 unsigned int num,
765 Elf_Shdr *sechdrs,
766 unsigned int symindex,
767 const char *strtab)
768{
769 struct kernel_param *kp;
770 unsigned int i;
771 int ret;
772
773 kp = kmalloc(sizeof(kp[0]) * num, GFP_KERNEL);
774 if (!kp)
775 return -ENOMEM;
776
777 for (i = 0; i < num; i++) {
778 char sym_name[128 + sizeof(MODULE_SYMBOL_PREFIX)];
779
780 snprintf(sym_name, sizeof(sym_name), "%s%s",
781 MODULE_SYMBOL_PREFIX, obsparm[i].name);
782
783 kp[i].name = obsparm[i].name;
784 kp[i].perm = 000;
785 kp[i].set = set_obsolete;
786 kp[i].get = NULL;
787 obsparm[i].addr
788 = (void *)find_local_symbol(sechdrs, symindex, strtab,
789 sym_name);
790 if (!obsparm[i].addr) {
791 printk("%s: falsely claims to have parameter %s\n",
792 name, obsparm[i].name);
793 ret = -EINVAL;
794 goto out;
795 }
796 kp[i].arg = &obsparm[i];
797 }
798
799 ret = parse_args(name, args, kp, num, NULL);
800 out:
801 kfree(kp);
802 return ret;
803}
804#else
805static int obsolete_params(const char *name,
806 char *args,
807 struct obsolete_modparm obsparm[],
808 unsigned int num,
809 Elf_Shdr *sechdrs,
810 unsigned int symindex,
811 const char *strtab)
812{
813 if (num != 0)
814 printk(KERN_WARNING "%s: Ignoring obsolete parameters\n",
815 name);
816 return 0;
817}
818#endif /* CONFIG_OBSOLETE_MODPARM */
819
820static const char vermagic[] = VERMAGIC_STRING;
821
822#ifdef CONFIG_MODVERSIONS
823static int check_version(Elf_Shdr *sechdrs,
824 unsigned int versindex,
825 const char *symname,
826 struct module *mod,
827 const unsigned long *crc)
828{
829 unsigned int i, num_versions;
830 struct modversion_info *versions;
831
832 /* Exporting module didn't supply crcs? OK, we're already tainted. */
833 if (!crc)
834 return 1;
835
836 versions = (void *) sechdrs[versindex].sh_addr;
837 num_versions = sechdrs[versindex].sh_size
838 / sizeof(struct modversion_info);
839
840 for (i = 0; i < num_versions; i++) {
841 if (strcmp(versions[i].name, symname) != 0)
842 continue;
843
844 if (versions[i].crc == *crc)
845 return 1;
846 printk("%s: disagrees about version of symbol %s\n",
847 mod->name, symname);
848 DEBUGP("Found checksum %lX vs module %lX\n",
849 *crc, versions[i].crc);
850 return 0;
851 }
852 /* Not in module's version table. OK, but that taints the kernel. */
853 if (!(tainted & TAINT_FORCED_MODULE)) {
854 printk("%s: no version for \"%s\" found: kernel tainted.\n",
855 mod->name, symname);
856 tainted |= TAINT_FORCED_MODULE;
857 }
858 return 1;
859}
860
861static inline int check_modstruct_version(Elf_Shdr *sechdrs,
862 unsigned int versindex,
863 struct module *mod)
864{
865 const unsigned long *crc;
866 struct module *owner;
867
868 if (!__find_symbol("struct_module", &owner, &crc, 1))
869 BUG();
870 return check_version(sechdrs, versindex, "struct_module", mod,
871 crc);
872}
873
874/* First part is kernel version, which we ignore. */
875static inline int same_magic(const char *amagic, const char *bmagic)
876{
877 amagic += strcspn(amagic, " ");
878 bmagic += strcspn(bmagic, " ");
879 return strcmp(amagic, bmagic) == 0;
880}
881#else
882static inline int check_version(Elf_Shdr *sechdrs,
883 unsigned int versindex,
884 const char *symname,
885 struct module *mod,
886 const unsigned long *crc)
887{
888 return 1;
889}
890
891static inline int check_modstruct_version(Elf_Shdr *sechdrs,
892 unsigned int versindex,
893 struct module *mod)
894{
895 return 1;
896}
897
898static inline int same_magic(const char *amagic, const char *bmagic)
899{
900 return strcmp(amagic, bmagic) == 0;
901}
902#endif /* CONFIG_MODVERSIONS */
903
904/* Resolve a symbol for this module. I.e. if we find one, record usage.
905 Must be holding module_mutex. */
906static unsigned long resolve_symbol(Elf_Shdr *sechdrs,
907 unsigned int versindex,
908 const char *name,
909 struct module *mod)
910{
911 struct module *owner;
912 unsigned long ret;
913 const unsigned long *crc;
914
915 spin_lock_irq(&modlist_lock);
916 ret = __find_symbol(name, &owner, &crc, mod->license_gplok);
917 if (ret) {
918 /* use_module can fail due to OOM, or module unloading */
919 if (!check_version(sechdrs, versindex, name, mod, crc) ||
920 !use_module(mod, owner))
921 ret = 0;
922 }
923 spin_unlock_irq(&modlist_lock);
924 return ret;
925}
926
927
928/*
929 * /sys/module/foo/sections stuff
930 * J. Corbet <corbet@lwn.net>
931 */
932#ifdef CONFIG_KALLSYMS
933static ssize_t module_sect_show(struct module_attribute *mattr,
934 struct module *mod, char *buf)
935{
936 struct module_sect_attr *sattr =
937 container_of(mattr, struct module_sect_attr, mattr);
938 return sprintf(buf, "0x%lx\n", sattr->address);
939}
940
941static void add_sect_attrs(struct module *mod, unsigned int nsect,
942 char *secstrings, Elf_Shdr *sechdrs)
943{
944 unsigned int nloaded = 0, i, size[2];
945 struct module_sect_attrs *sect_attrs;
946 struct module_sect_attr *sattr;
947 struct attribute **gattr;
948
949 /* Count loaded sections and allocate structures */
950 for (i = 0; i < nsect; i++)
951 if (sechdrs[i].sh_flags & SHF_ALLOC)
952 nloaded++;
953 size[0] = ALIGN(sizeof(*sect_attrs)
954 + nloaded * sizeof(sect_attrs->attrs[0]),
955 sizeof(sect_attrs->grp.attrs[0]));
956 size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]);
957 if (! (sect_attrs = kmalloc(size[0] + size[1], GFP_KERNEL)))
958 return;
959
960 /* Setup section attributes. */
961 sect_attrs->grp.name = "sections";
962 sect_attrs->grp.attrs = (void *)sect_attrs + size[0];
963
964 sattr = &sect_attrs->attrs[0];
965 gattr = &sect_attrs->grp.attrs[0];
966 for (i = 0; i < nsect; i++) {
967 if (! (sechdrs[i].sh_flags & SHF_ALLOC))
968 continue;
969 sattr->address = sechdrs[i].sh_addr;
970 strlcpy(sattr->name, secstrings + sechdrs[i].sh_name,
971 MODULE_SECT_NAME_LEN);
972 sattr->mattr.show = module_sect_show;
973 sattr->mattr.store = NULL;
974 sattr->mattr.attr.name = sattr->name;
975 sattr->mattr.attr.owner = mod;
976 sattr->mattr.attr.mode = S_IRUGO;
977 *(gattr++) = &(sattr++)->mattr.attr;
978 }
979 *gattr = NULL;
980
981 if (sysfs_create_group(&mod->mkobj.kobj, &sect_attrs->grp))
982 goto out;
983
984 mod->sect_attrs = sect_attrs;
985 return;
986 out:
987 kfree(sect_attrs);
988}
989
990static void remove_sect_attrs(struct module *mod)
991{
992 if (mod->sect_attrs) {
993 sysfs_remove_group(&mod->mkobj.kobj,
994 &mod->sect_attrs->grp);
995 /* We are positive that no one is using any sect attrs
996 * at this point. Deallocate immediately. */
997 kfree(mod->sect_attrs);
998 mod->sect_attrs = NULL;
999 }
1000}
1001
1002
1003#else
1004static inline void add_sect_attrs(struct module *mod, unsigned int nsect,
1005 char *sectstrings, Elf_Shdr *sechdrs)
1006{
1007}
1008
1009static inline void remove_sect_attrs(struct module *mod)
1010{
1011}
1012#endif /* CONFIG_KALLSYMS */
1013
1014
1015#ifdef CONFIG_MODULE_UNLOAD
1016static inline int module_add_refcnt_attr(struct module *mod)
1017{
1018 return sysfs_create_file(&mod->mkobj.kobj, &refcnt.attr);
1019}
1020static void module_remove_refcnt_attr(struct module *mod)
1021{
1022 return sysfs_remove_file(&mod->mkobj.kobj, &refcnt.attr);
1023}
1024#else
1025static inline int module_add_refcnt_attr(struct module *mod)
1026{
1027 return 0;
1028}
1029static void module_remove_refcnt_attr(struct module *mod)
1030{
1031}
1032#endif
1033
1034
1035static int mod_sysfs_setup(struct module *mod,
1036 struct kernel_param *kparam,
1037 unsigned int num_params)
1038{
1039 int err;
1040
1041 memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
1042 err = kobject_set_name(&mod->mkobj.kobj, "%s", mod->name);
1043 if (err)
1044 goto out;
1045 kobj_set_kset_s(&mod->mkobj, module_subsys);
1046 mod->mkobj.mod = mod;
1047 err = kobject_register(&mod->mkobj.kobj);
1048 if (err)
1049 goto out;
1050
1051 err = module_add_refcnt_attr(mod);
1052 if (err)
1053 goto out_unreg;
1054
1055 err = module_param_sysfs_setup(mod, kparam, num_params);
1056 if (err)
1057 goto out_unreg;
1058
1059 return 0;
1060
1061out_unreg:
1062 kobject_unregister(&mod->mkobj.kobj);
1063out:
1064 return err;
1065}
1066
1067static void mod_kobject_remove(struct module *mod)
1068{
1069 module_remove_refcnt_attr(mod);
1070 module_param_sysfs_remove(mod);
1071
1072 kobject_unregister(&mod->mkobj.kobj);
1073}
1074
1075/*
1076 * unlink the module with the whole machine is stopped with interrupts off
1077 * - this defends against kallsyms not taking locks
1078 */
1079static int __unlink_module(void *_mod)
1080{
1081 struct module *mod = _mod;
1082 list_del(&mod->list);
1083 return 0;
1084}
1085
1086/* Free a module, remove from lists, etc (must hold module mutex). */
1087static void free_module(struct module *mod)
1088{
1089 /* Delete from various lists */
1090 stop_machine_run(__unlink_module, mod, NR_CPUS);
1091 remove_sect_attrs(mod);
1092 mod_kobject_remove(mod);
1093
1094 /* Arch-specific cleanup. */
1095 module_arch_cleanup(mod);
1096
1097 /* Module unload stuff */
1098 module_unload_free(mod);
1099
1100 /* This may be NULL, but that's OK */
1101 module_free(mod, mod->module_init);
1102 kfree(mod->args);
1103 if (mod->percpu)
1104 percpu_modfree(mod->percpu);
1105
1106 /* Finally, free the core (containing the module structure) */
1107 module_free(mod, mod->module_core);
1108}
1109
1110void *__symbol_get(const char *symbol)
1111{
1112 struct module *owner;
1113 unsigned long value, flags;
1114 const unsigned long *crc;
1115
1116 spin_lock_irqsave(&modlist_lock, flags);
1117 value = __find_symbol(symbol, &owner, &crc, 1);
1118 if (value && !strong_try_module_get(owner))
1119 value = 0;
1120 spin_unlock_irqrestore(&modlist_lock, flags);
1121
1122 return (void *)value;
1123}
1124EXPORT_SYMBOL_GPL(__symbol_get);
1125
1126/* Change all symbols so that sh_value encodes the pointer directly. */
1127static int simplify_symbols(Elf_Shdr *sechdrs,
1128 unsigned int symindex,
1129 const char *strtab,
1130 unsigned int versindex,
1131 unsigned int pcpuindex,
1132 struct module *mod)
1133{
1134 Elf_Sym *sym = (void *)sechdrs[symindex].sh_addr;
1135 unsigned long secbase;
1136 unsigned int i, n = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
1137 int ret = 0;
1138
1139 for (i = 1; i < n; i++) {
1140 switch (sym[i].st_shndx) {
1141 case SHN_COMMON:
1142 /* We compiled with -fno-common. These are not
1143 supposed to happen. */
1144 DEBUGP("Common symbol: %s\n", strtab + sym[i].st_name);
1145 printk("%s: please compile with -fno-common\n",
1146 mod->name);
1147 ret = -ENOEXEC;
1148 break;
1149
1150 case SHN_ABS:
1151 /* Don't need to do anything */
1152 DEBUGP("Absolute symbol: 0x%08lx\n",
1153 (long)sym[i].st_value);
1154 break;
1155
1156 case SHN_UNDEF:
1157 sym[i].st_value
1158 = resolve_symbol(sechdrs, versindex,
1159 strtab + sym[i].st_name, mod);
1160
1161 /* Ok if resolved. */
1162 if (sym[i].st_value != 0)
1163 break;
1164 /* Ok if weak. */
1165 if (ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
1166 break;
1167
1168 printk(KERN_WARNING "%s: Unknown symbol %s\n",
1169 mod->name, strtab + sym[i].st_name);
1170 ret = -ENOENT;
1171 break;
1172
1173 default:
1174 /* Divert to percpu allocation if a percpu var. */
1175 if (sym[i].st_shndx == pcpuindex)
1176 secbase = (unsigned long)mod->percpu;
1177 else
1178 secbase = sechdrs[sym[i].st_shndx].sh_addr;
1179 sym[i].st_value += secbase;
1180 break;
1181 }
1182 }
1183
1184 return ret;
1185}
1186
1187/* Update size with this section: return offset. */
1188static long get_offset(unsigned long *size, Elf_Shdr *sechdr)
1189{
1190 long ret;
1191
1192 ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
1193 *size = ret + sechdr->sh_size;
1194 return ret;
1195}
1196
1197/* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
1198 might -- code, read-only data, read-write data, small data. Tally
1199 sizes, and place the offsets into sh_entsize fields: high bit means it
1200 belongs in init. */
1201static void layout_sections(struct module *mod,
1202 const Elf_Ehdr *hdr,
1203 Elf_Shdr *sechdrs,
1204 const char *secstrings)
1205{
1206 static unsigned long const masks[][2] = {
1207 /* NOTE: all executable code must be the first section
1208 * in this array; otherwise modify the text_size
1209 * finder in the two loops below */
1210 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
1211 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
1212 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
1213 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
1214 };
1215 unsigned int m, i;
1216
1217 for (i = 0; i < hdr->e_shnum; i++)
1218 sechdrs[i].sh_entsize = ~0UL;
1219
1220 DEBUGP("Core section allocation order:\n");
1221 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
1222 for (i = 0; i < hdr->e_shnum; ++i) {
1223 Elf_Shdr *s = &sechdrs[i];
1224
1225 if ((s->sh_flags & masks[m][0]) != masks[m][0]
1226 || (s->sh_flags & masks[m][1])
1227 || s->sh_entsize != ~0UL
1228 || strncmp(secstrings + s->sh_name,
1229 ".init", 5) == 0)
1230 continue;
1231 s->sh_entsize = get_offset(&mod->core_size, s);
1232 DEBUGP("\t%s\n", secstrings + s->sh_name);
1233 }
1234 if (m == 0)
1235 mod->core_text_size = mod->core_size;
1236 }
1237
1238 DEBUGP("Init section allocation order:\n");
1239 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
1240 for (i = 0; i < hdr->e_shnum; ++i) {
1241 Elf_Shdr *s = &sechdrs[i];
1242
1243 if ((s->sh_flags & masks[m][0]) != masks[m][0]
1244 || (s->sh_flags & masks[m][1])
1245 || s->sh_entsize != ~0UL
1246 || strncmp(secstrings + s->sh_name,
1247 ".init", 5) != 0)
1248 continue;
1249 s->sh_entsize = (get_offset(&mod->init_size, s)
1250 | INIT_OFFSET_MASK);
1251 DEBUGP("\t%s\n", secstrings + s->sh_name);
1252 }
1253 if (m == 0)
1254 mod->init_text_size = mod->init_size;
1255 }
1256}
1257
1258static inline int license_is_gpl_compatible(const char *license)
1259{
1260 return (strcmp(license, "GPL") == 0
1261 || strcmp(license, "GPL v2") == 0
1262 || strcmp(license, "GPL and additional rights") == 0
1263 || strcmp(license, "Dual BSD/GPL") == 0
1264 || strcmp(license, "Dual MPL/GPL") == 0);
1265}
1266
1267static void set_license(struct module *mod, const char *license)
1268{
1269 if (!license)
1270 license = "unspecified";
1271
1272 mod->license_gplok = license_is_gpl_compatible(license);
1273 if (!mod->license_gplok && !(tainted & TAINT_PROPRIETARY_MODULE)) {
1274 printk(KERN_WARNING "%s: module license '%s' taints kernel.\n",
1275 mod->name, license);
1276 tainted |= TAINT_PROPRIETARY_MODULE;
1277 }
1278}
1279
1280/* Parse tag=value strings from .modinfo section */
1281static char *next_string(char *string, unsigned long *secsize)
1282{
1283 /* Skip non-zero chars */
1284 while (string[0]) {
1285 string++;
1286 if ((*secsize)-- <= 1)
1287 return NULL;
1288 }
1289
1290 /* Skip any zero padding. */
1291 while (!string[0]) {
1292 string++;
1293 if ((*secsize)-- <= 1)
1294 return NULL;
1295 }
1296 return string;
1297}
1298
1299static char *get_modinfo(Elf_Shdr *sechdrs,
1300 unsigned int info,
1301 const char *tag)
1302{
1303 char *p;
1304 unsigned int taglen = strlen(tag);
1305 unsigned long size = sechdrs[info].sh_size;
1306
1307 for (p = (char *)sechdrs[info].sh_addr; p; p = next_string(p, &size)) {
1308 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
1309 return p + taglen + 1;
1310 }
1311 return NULL;
1312}
1313
1314#ifdef CONFIG_KALLSYMS
1315int is_exported(const char *name, const struct module *mod)
1316{
1317 unsigned int i;
1318
1319 if (!mod) {
1320 for (i = 0; __start___ksymtab+i < __stop___ksymtab; i++)
1321 if (strcmp(__start___ksymtab[i].name, name) == 0)
1322 return 1;
1323 return 0;
1324 }
1325 for (i = 0; i < mod->num_syms; i++)
1326 if (strcmp(mod->syms[i].name, name) == 0)
1327 return 1;
1328 return 0;
1329}
1330
1331/* As per nm */
1332static char elf_type(const Elf_Sym *sym,
1333 Elf_Shdr *sechdrs,
1334 const char *secstrings,
1335 struct module *mod)
1336{
1337 if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
1338 if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
1339 return 'v';
1340 else
1341 return 'w';
1342 }
1343 if (sym->st_shndx == SHN_UNDEF)
1344 return 'U';
1345 if (sym->st_shndx == SHN_ABS)
1346 return 'a';
1347 if (sym->st_shndx >= SHN_LORESERVE)
1348 return '?';
1349 if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
1350 return 't';
1351 if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
1352 && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
1353 if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
1354 return 'r';
1355 else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
1356 return 'g';
1357 else
1358 return 'd';
1359 }
1360 if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
1361 if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
1362 return 's';
1363 else
1364 return 'b';
1365 }
1366 if (strncmp(secstrings + sechdrs[sym->st_shndx].sh_name,
1367 ".debug", strlen(".debug")) == 0)
1368 return 'n';
1369 return '?';
1370}
1371
1372static void add_kallsyms(struct module *mod,
1373 Elf_Shdr *sechdrs,
1374 unsigned int symindex,
1375 unsigned int strindex,
1376 const char *secstrings)
1377{
1378 unsigned int i;
1379
1380 mod->symtab = (void *)sechdrs[symindex].sh_addr;
1381 mod->num_symtab = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
1382 mod->strtab = (void *)sechdrs[strindex].sh_addr;
1383
1384 /* Set types up while we still have access to sections. */
1385 for (i = 0; i < mod->num_symtab; i++)
1386 mod->symtab[i].st_info
1387 = elf_type(&mod->symtab[i], sechdrs, secstrings, mod);
1388}
1389#else
1390static inline void add_kallsyms(struct module *mod,
1391 Elf_Shdr *sechdrs,
1392 unsigned int symindex,
1393 unsigned int strindex,
1394 const char *secstrings)
1395{
1396}
1397#endif /* CONFIG_KALLSYMS */
1398
1399/* Allocate and load the module: note that size of section 0 is always
1400 zero, and we rely on this for optional sections. */
1401static struct module *load_module(void __user *umod,
1402 unsigned long len,
1403 const char __user *uargs)
1404{
1405 Elf_Ehdr *hdr;
1406 Elf_Shdr *sechdrs;
1407 char *secstrings, *args, *modmagic, *strtab = NULL;
1408 unsigned int i, symindex = 0, strindex = 0, setupindex, exindex,
1409 exportindex, modindex, obsparmindex, infoindex, gplindex,
1410 crcindex, gplcrcindex, versindex, pcpuindex;
1411 long arglen;
1412 struct module *mod;
1413 long err = 0;
1414 void *percpu = NULL, *ptr = NULL; /* Stops spurious gcc warning */
1415 struct exception_table_entry *extable;
1416
1417 DEBUGP("load_module: umod=%p, len=%lu, uargs=%p\n",
1418 umod, len, uargs);
1419 if (len < sizeof(*hdr))
1420 return ERR_PTR(-ENOEXEC);
1421
1422 /* Suck in entire file: we'll want most of it. */
1423 /* vmalloc barfs on "unusual" numbers. Check here */
1424 if (len > 64 * 1024 * 1024 || (hdr = vmalloc(len)) == NULL)
1425 return ERR_PTR(-ENOMEM);
1426 if (copy_from_user(hdr, umod, len) != 0) {
1427 err = -EFAULT;
1428 goto free_hdr;
1429 }
1430
1431 /* Sanity checks against insmoding binaries or wrong arch,
1432 weird elf version */
1433 if (memcmp(hdr->e_ident, ELFMAG, 4) != 0
1434 || hdr->e_type != ET_REL
1435 || !elf_check_arch(hdr)
1436 || hdr->e_shentsize != sizeof(*sechdrs)) {
1437 err = -ENOEXEC;
1438 goto free_hdr;
1439 }
1440
1441 if (len < hdr->e_shoff + hdr->e_shnum * sizeof(Elf_Shdr))
1442 goto truncated;
1443
1444 /* Convenience variables */
1445 sechdrs = (void *)hdr + hdr->e_shoff;
1446 secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
1447 sechdrs[0].sh_addr = 0;
1448
1449 for (i = 1; i < hdr->e_shnum; i++) {
1450 if (sechdrs[i].sh_type != SHT_NOBITS
1451 && len < sechdrs[i].sh_offset + sechdrs[i].sh_size)
1452 goto truncated;
1453
1454 /* Mark all sections sh_addr with their address in the
1455 temporary image. */
1456 sechdrs[i].sh_addr = (size_t)hdr + sechdrs[i].sh_offset;
1457
1458 /* Internal symbols and strings. */
1459 if (sechdrs[i].sh_type == SHT_SYMTAB) {
1460 symindex = i;
1461 strindex = sechdrs[i].sh_link;
1462 strtab = (char *)hdr + sechdrs[strindex].sh_offset;
1463 }
1464#ifndef CONFIG_MODULE_UNLOAD
1465 /* Don't load .exit sections */
1466 if (strncmp(secstrings+sechdrs[i].sh_name, ".exit", 5) == 0)
1467 sechdrs[i].sh_flags &= ~(unsigned long)SHF_ALLOC;
1468#endif
1469 }
1470
1471 modindex = find_sec(hdr, sechdrs, secstrings,
1472 ".gnu.linkonce.this_module");
1473 if (!modindex) {
1474 printk(KERN_WARNING "No module found in object\n");
1475 err = -ENOEXEC;
1476 goto free_hdr;
1477 }
1478 mod = (void *)sechdrs[modindex].sh_addr;
1479
1480 if (symindex == 0) {
1481 printk(KERN_WARNING "%s: module has no symbols (stripped?)\n",
1482 mod->name);
1483 err = -ENOEXEC;
1484 goto free_hdr;
1485 }
1486
1487 /* Optional sections */
1488 exportindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab");
1489 gplindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_gpl");
1490 crcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab");
1491 gplcrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_gpl");
1492 setupindex = find_sec(hdr, sechdrs, secstrings, "__param");
1493 exindex = find_sec(hdr, sechdrs, secstrings, "__ex_table");
1494 obsparmindex = find_sec(hdr, sechdrs, secstrings, "__obsparm");
1495 versindex = find_sec(hdr, sechdrs, secstrings, "__versions");
1496 infoindex = find_sec(hdr, sechdrs, secstrings, ".modinfo");
1497 pcpuindex = find_pcpusec(hdr, sechdrs, secstrings);
1498
1499 /* Don't keep modinfo section */
1500 sechdrs[infoindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
1501#ifdef CONFIG_KALLSYMS
1502 /* Keep symbol and string tables for decoding later. */
1503 sechdrs[symindex].sh_flags |= SHF_ALLOC;
1504 sechdrs[strindex].sh_flags |= SHF_ALLOC;
1505#endif
1506
1507 /* Check module struct version now, before we try to use module. */
1508 if (!check_modstruct_version(sechdrs, versindex, mod)) {
1509 err = -ENOEXEC;
1510 goto free_hdr;
1511 }
1512
1513 modmagic = get_modinfo(sechdrs, infoindex, "vermagic");
1514 /* This is allowed: modprobe --force will invalidate it. */
1515 if (!modmagic) {
1516 tainted |= TAINT_FORCED_MODULE;
1517 printk(KERN_WARNING "%s: no version magic, tainting kernel.\n",
1518 mod->name);
1519 } else if (!same_magic(modmagic, vermagic)) {
1520 printk(KERN_ERR "%s: version magic '%s' should be '%s'\n",
1521 mod->name, modmagic, vermagic);
1522 err = -ENOEXEC;
1523 goto free_hdr;
1524 }
1525
1526 /* Now copy in args */
1527 arglen = strlen_user(uargs);
1528 if (!arglen) {
1529 err = -EFAULT;
1530 goto free_hdr;
1531 }
1532 args = kmalloc(arglen, GFP_KERNEL);
1533 if (!args) {
1534 err = -ENOMEM;
1535 goto free_hdr;
1536 }
1537 if (copy_from_user(args, uargs, arglen) != 0) {
1538 err = -EFAULT;
1539 goto free_mod;
1540 }
1541
1542 if (find_module(mod->name)) {
1543 err = -EEXIST;
1544 goto free_mod;
1545 }
1546
1547 mod->state = MODULE_STATE_COMING;
1548
1549 /* Allow arches to frob section contents and sizes. */
1550 err = module_frob_arch_sections(hdr, sechdrs, secstrings, mod);
1551 if (err < 0)
1552 goto free_mod;
1553
1554 if (pcpuindex) {
1555 /* We have a special allocation for this section. */
1556 percpu = percpu_modalloc(sechdrs[pcpuindex].sh_size,
1557 sechdrs[pcpuindex].sh_addralign);
1558 if (!percpu) {
1559 err = -ENOMEM;
1560 goto free_mod;
1561 }
1562 sechdrs[pcpuindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
1563 mod->percpu = percpu;
1564 }
1565
1566 /* Determine total sizes, and put offsets in sh_entsize. For now
1567 this is done generically; there doesn't appear to be any
1568 special cases for the architectures. */
1569 layout_sections(mod, hdr, sechdrs, secstrings);
1570
1571 /* Do the allocs. */
1572 ptr = module_alloc(mod->core_size);
1573 if (!ptr) {
1574 err = -ENOMEM;
1575 goto free_percpu;
1576 }
1577 memset(ptr, 0, mod->core_size);
1578 mod->module_core = ptr;
1579
1580 ptr = module_alloc(mod->init_size);
1581 if (!ptr && mod->init_size) {
1582 err = -ENOMEM;
1583 goto free_core;
1584 }
1585 memset(ptr, 0, mod->init_size);
1586 mod->module_init = ptr;
1587
1588 /* Transfer each section which specifies SHF_ALLOC */
1589 DEBUGP("final section addresses:\n");
1590 for (i = 0; i < hdr->e_shnum; i++) {
1591 void *dest;
1592
1593 if (!(sechdrs[i].sh_flags & SHF_ALLOC))
1594 continue;
1595
1596 if (sechdrs[i].sh_entsize & INIT_OFFSET_MASK)
1597 dest = mod->module_init
1598 + (sechdrs[i].sh_entsize & ~INIT_OFFSET_MASK);
1599 else
1600 dest = mod->module_core + sechdrs[i].sh_entsize;
1601
1602 if (sechdrs[i].sh_type != SHT_NOBITS)
1603 memcpy(dest, (void *)sechdrs[i].sh_addr,
1604 sechdrs[i].sh_size);
1605 /* Update sh_addr to point to copy in image. */
1606 sechdrs[i].sh_addr = (unsigned long)dest;
1607 DEBUGP("\t0x%lx %s\n", sechdrs[i].sh_addr, secstrings + sechdrs[i].sh_name);
1608 }
1609 /* Module has been moved. */
1610 mod = (void *)sechdrs[modindex].sh_addr;
1611
1612 /* Now we've moved module, initialize linked lists, etc. */
1613 module_unload_init(mod);
1614
1615 /* Set up license info based on the info section */
1616 set_license(mod, get_modinfo(sechdrs, infoindex, "license"));
1617
1618 /* Fix up syms, so that st_value is a pointer to location. */
1619 err = simplify_symbols(sechdrs, symindex, strtab, versindex, pcpuindex,
1620 mod);
1621 if (err < 0)
1622 goto cleanup;
1623
1624 /* Set up EXPORTed & EXPORT_GPLed symbols (section 0 is 0 length) */
1625 mod->num_syms = sechdrs[exportindex].sh_size / sizeof(*mod->syms);
1626 mod->syms = (void *)sechdrs[exportindex].sh_addr;
1627 if (crcindex)
1628 mod->crcs = (void *)sechdrs[crcindex].sh_addr;
1629 mod->num_gpl_syms = sechdrs[gplindex].sh_size / sizeof(*mod->gpl_syms);
1630 mod->gpl_syms = (void *)sechdrs[gplindex].sh_addr;
1631 if (gplcrcindex)
1632 mod->gpl_crcs = (void *)sechdrs[gplcrcindex].sh_addr;
1633
1634#ifdef CONFIG_MODVERSIONS
1635 if ((mod->num_syms && !crcindex) ||
1636 (mod->num_gpl_syms && !gplcrcindex)) {
1637 printk(KERN_WARNING "%s: No versions for exported symbols."
1638 " Tainting kernel.\n", mod->name);
1639 tainted |= TAINT_FORCED_MODULE;
1640 }
1641#endif
1642
1643 /* Now do relocations. */
1644 for (i = 1; i < hdr->e_shnum; i++) {
1645 const char *strtab = (char *)sechdrs[strindex].sh_addr;
1646 unsigned int info = sechdrs[i].sh_info;
1647
1648 /* Not a valid relocation section? */
1649 if (info >= hdr->e_shnum)
1650 continue;
1651
1652 /* Don't bother with non-allocated sections */
1653 if (!(sechdrs[info].sh_flags & SHF_ALLOC))
1654 continue;
1655
1656 if (sechdrs[i].sh_type == SHT_REL)
1657 err = apply_relocate(sechdrs, strtab, symindex, i,mod);
1658 else if (sechdrs[i].sh_type == SHT_RELA)
1659 err = apply_relocate_add(sechdrs, strtab, symindex, i,
1660 mod);
1661 if (err < 0)
1662 goto cleanup;
1663 }
1664
1665 /* Set up and sort exception table */
1666 mod->num_exentries = sechdrs[exindex].sh_size / sizeof(*mod->extable);
1667 mod->extable = extable = (void *)sechdrs[exindex].sh_addr;
1668 sort_extable(extable, extable + mod->num_exentries);
1669
1670 /* Finally, copy percpu area over. */
1671 percpu_modcopy(mod->percpu, (void *)sechdrs[pcpuindex].sh_addr,
1672 sechdrs[pcpuindex].sh_size);
1673
1674 add_kallsyms(mod, sechdrs, symindex, strindex, secstrings);
1675
1676 err = module_finalize(hdr, sechdrs, mod);
1677 if (err < 0)
1678 goto cleanup;
1679
1680 mod->args = args;
1681 if (obsparmindex) {
1682 err = obsolete_params(mod->name, mod->args,
1683 (struct obsolete_modparm *)
1684 sechdrs[obsparmindex].sh_addr,
1685 sechdrs[obsparmindex].sh_size
1686 / sizeof(struct obsolete_modparm),
1687 sechdrs, symindex,
1688 (char *)sechdrs[strindex].sh_addr);
1689 if (setupindex)
1690 printk(KERN_WARNING "%s: Ignoring new-style "
1691 "parameters in presence of obsolete ones\n",
1692 mod->name);
1693 } else {
1694 /* Size of section 0 is 0, so this works well if no params */
1695 err = parse_args(mod->name, mod->args,
1696 (struct kernel_param *)
1697 sechdrs[setupindex].sh_addr,
1698 sechdrs[setupindex].sh_size
1699 / sizeof(struct kernel_param),
1700 NULL);
1701 }
1702 if (err < 0)
1703 goto arch_cleanup;
1704
1705 err = mod_sysfs_setup(mod,
1706 (struct kernel_param *)
1707 sechdrs[setupindex].sh_addr,
1708 sechdrs[setupindex].sh_size
1709 / sizeof(struct kernel_param));
1710 if (err < 0)
1711 goto arch_cleanup;
1712 add_sect_attrs(mod, hdr->e_shnum, secstrings, sechdrs);
1713
1714 /* Get rid of temporary copy */
1715 vfree(hdr);
1716
1717 /* Done! */
1718 return mod;
1719
1720 arch_cleanup:
1721 module_arch_cleanup(mod);
1722 cleanup:
1723 module_unload_free(mod);
1724 module_free(mod, mod->module_init);
1725 free_core:
1726 module_free(mod, mod->module_core);
1727 free_percpu:
1728 if (percpu)
1729 percpu_modfree(percpu);
1730 free_mod:
1731 kfree(args);
1732 free_hdr:
1733 vfree(hdr);
1734 if (err < 0) return ERR_PTR(err);
1735 else return ptr;
1736
1737 truncated:
1738 printk(KERN_ERR "Module len %lu truncated\n", len);
1739 err = -ENOEXEC;
1740 goto free_hdr;
1741}
1742
1743/*
1744 * link the module with the whole machine is stopped with interrupts off
1745 * - this defends against kallsyms not taking locks
1746 */
1747static int __link_module(void *_mod)
1748{
1749 struct module *mod = _mod;
1750 list_add(&mod->list, &modules);
1751 return 0;
1752}
1753
1754/* This is where the real work happens */
1755asmlinkage long
1756sys_init_module(void __user *umod,
1757 unsigned long len,
1758 const char __user *uargs)
1759{
1760 struct module *mod;
1761 int ret = 0;
1762
1763 /* Must have permission */
1764 if (!capable(CAP_SYS_MODULE))
1765 return -EPERM;
1766
1767 /* Only one module load at a time, please */
1768 if (down_interruptible(&module_mutex) != 0)
1769 return -EINTR;
1770
1771 /* Do all the hard work */
1772 mod = load_module(umod, len, uargs);
1773 if (IS_ERR(mod)) {
1774 up(&module_mutex);
1775 return PTR_ERR(mod);
1776 }
1777
1778 /* Flush the instruction cache, since we've played with text */
1779 if (mod->module_init)
1780 flush_icache_range((unsigned long)mod->module_init,
1781 (unsigned long)mod->module_init
1782 + mod->init_size);
1783 flush_icache_range((unsigned long)mod->module_core,
1784 (unsigned long)mod->module_core + mod->core_size);
1785
1786 /* Now sew it into the lists. They won't access us, since
1787 strong_try_module_get() will fail. */
1788 stop_machine_run(__link_module, mod, NR_CPUS);
1789
1790 /* Drop lock so they can recurse */
1791 up(&module_mutex);
1792
1793 down(&notify_mutex);
1794 notifier_call_chain(&module_notify_list, MODULE_STATE_COMING, mod);
1795 up(&notify_mutex);
1796
1797 /* Start the module */
1798 if (mod->init != NULL)
1799 ret = mod->init();
1800 if (ret < 0) {
1801 /* Init routine failed: abort. Try to protect us from
1802 buggy refcounters. */
1803 mod->state = MODULE_STATE_GOING;
1804 synchronize_kernel();
1805 if (mod->unsafe)
1806 printk(KERN_ERR "%s: module is now stuck!\n",
1807 mod->name);
1808 else {
1809 module_put(mod);
1810 down(&module_mutex);
1811 free_module(mod);
1812 up(&module_mutex);
1813 }
1814 return ret;
1815 }
1816
1817 /* Now it's a first class citizen! */
1818 down(&module_mutex);
1819 mod->state = MODULE_STATE_LIVE;
1820 /* Drop initial reference. */
1821 module_put(mod);
1822 module_free(mod, mod->module_init);
1823 mod->module_init = NULL;
1824 mod->init_size = 0;
1825 mod->init_text_size = 0;
1826 up(&module_mutex);
1827
1828 return 0;
1829}
1830
1831static inline int within(unsigned long addr, void *start, unsigned long size)
1832{
1833 return ((void *)addr >= start && (void *)addr < start + size);
1834}
1835
1836#ifdef CONFIG_KALLSYMS
1837/*
1838 * This ignores the intensely annoying "mapping symbols" found
1839 * in ARM ELF files: $a, $t and $d.
1840 */
1841static inline int is_arm_mapping_symbol(const char *str)
1842{
1843 return str[0] == '$' && strchr("atd", str[1])
1844 && (str[2] == '\0' || str[2] == '.');
1845}
1846
1847static const char *get_ksymbol(struct module *mod,
1848 unsigned long addr,
1849 unsigned long *size,
1850 unsigned long *offset)
1851{
1852 unsigned int i, best = 0;
1853 unsigned long nextval;
1854
1855 /* At worse, next value is at end of module */
1856 if (within(addr, mod->module_init, mod->init_size))
1857 nextval = (unsigned long)mod->module_init+mod->init_text_size;
1858 else
1859 nextval = (unsigned long)mod->module_core+mod->core_text_size;
1860
1861 /* Scan for closest preceeding symbol, and next symbol. (ELF
1862 starts real symbols at 1). */
1863 for (i = 1; i < mod->num_symtab; i++) {
1864 if (mod->symtab[i].st_shndx == SHN_UNDEF)
1865 continue;
1866
1867 /* We ignore unnamed symbols: they're uninformative
1868 * and inserted at a whim. */
1869 if (mod->symtab[i].st_value <= addr
1870 && mod->symtab[i].st_value > mod->symtab[best].st_value
1871 && *(mod->strtab + mod->symtab[i].st_name) != '\0'
1872 && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
1873 best = i;
1874 if (mod->symtab[i].st_value > addr
1875 && mod->symtab[i].st_value < nextval
1876 && *(mod->strtab + mod->symtab[i].st_name) != '\0'
1877 && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
1878 nextval = mod->symtab[i].st_value;
1879 }
1880
1881 if (!best)
1882 return NULL;
1883
1884 *size = nextval - mod->symtab[best].st_value;
1885 *offset = addr - mod->symtab[best].st_value;
1886 return mod->strtab + mod->symtab[best].st_name;
1887}
1888
1889/* For kallsyms to ask for address resolution. NULL means not found.
1890 We don't lock, as this is used for oops resolution and races are a
1891 lesser concern. */
1892const char *module_address_lookup(unsigned long addr,
1893 unsigned long *size,
1894 unsigned long *offset,
1895 char **modname)
1896{
1897 struct module *mod;
1898
1899 list_for_each_entry(mod, &modules, list) {
1900 if (within(addr, mod->module_init, mod->init_size)
1901 || within(addr, mod->module_core, mod->core_size)) {
1902 *modname = mod->name;
1903 return get_ksymbol(mod, addr, size, offset);
1904 }
1905 }
1906 return NULL;
1907}
1908
1909struct module *module_get_kallsym(unsigned int symnum,
1910 unsigned long *value,
1911 char *type,
1912 char namebuf[128])
1913{
1914 struct module *mod;
1915
1916 down(&module_mutex);
1917 list_for_each_entry(mod, &modules, list) {
1918 if (symnum < mod->num_symtab) {
1919 *value = mod->symtab[symnum].st_value;
1920 *type = mod->symtab[symnum].st_info;
1921 strncpy(namebuf,
1922 mod->strtab + mod->symtab[symnum].st_name,
1923 127);
1924 up(&module_mutex);
1925 return mod;
1926 }
1927 symnum -= mod->num_symtab;
1928 }
1929 up(&module_mutex);
1930 return NULL;
1931}
1932
1933static unsigned long mod_find_symname(struct module *mod, const char *name)
1934{
1935 unsigned int i;
1936
1937 for (i = 0; i < mod->num_symtab; i++)
1938 if (strcmp(name, mod->strtab+mod->symtab[i].st_name) == 0)
1939 return mod->symtab[i].st_value;
1940 return 0;
1941}
1942
1943/* Look for this name: can be of form module:name. */
1944unsigned long module_kallsyms_lookup_name(const char *name)
1945{
1946 struct module *mod;
1947 char *colon;
1948 unsigned long ret = 0;
1949
1950 /* Don't lock: we're in enough trouble already. */
1951 if ((colon = strchr(name, ':')) != NULL) {
1952 *colon = '\0';
1953 if ((mod = find_module(name)) != NULL)
1954 ret = mod_find_symname(mod, colon+1);
1955 *colon = ':';
1956 } else {
1957 list_for_each_entry(mod, &modules, list)
1958 if ((ret = mod_find_symname(mod, name)) != 0)
1959 break;
1960 }
1961 return ret;
1962}
1963#endif /* CONFIG_KALLSYMS */
1964
1965/* Called by the /proc file system to return a list of modules. */
1966static void *m_start(struct seq_file *m, loff_t *pos)
1967{
1968 struct list_head *i;
1969 loff_t n = 0;
1970
1971 down(&module_mutex);
1972 list_for_each(i, &modules) {
1973 if (n++ == *pos)
1974 break;
1975 }
1976 if (i == &modules)
1977 return NULL;
1978 return i;
1979}
1980
1981static void *m_next(struct seq_file *m, void *p, loff_t *pos)
1982{
1983 struct list_head *i = p;
1984 (*pos)++;
1985 if (i->next == &modules)
1986 return NULL;
1987 return i->next;
1988}
1989
1990static void m_stop(struct seq_file *m, void *p)
1991{
1992 up(&module_mutex);
1993}
1994
1995static int m_show(struct seq_file *m, void *p)
1996{
1997 struct module *mod = list_entry(p, struct module, list);
1998 seq_printf(m, "%s %lu",
1999 mod->name, mod->init_size + mod->core_size);
2000 print_unload_info(m, mod);
2001
2002 /* Informative for users. */
2003 seq_printf(m, " %s",
2004 mod->state == MODULE_STATE_GOING ? "Unloading":
2005 mod->state == MODULE_STATE_COMING ? "Loading":
2006 "Live");
2007 /* Used by oprofile and other similar tools. */
2008 seq_printf(m, " 0x%p", mod->module_core);
2009
2010 seq_printf(m, "\n");
2011 return 0;
2012}
2013
2014/* Format: modulename size refcount deps address
2015
2016 Where refcount is a number or -, and deps is a comma-separated list
2017 of depends or -.
2018*/
2019struct seq_operations modules_op = {
2020 .start = m_start,
2021 .next = m_next,
2022 .stop = m_stop,
2023 .show = m_show
2024};
2025
2026/* Given an address, look for it in the module exception tables. */
2027const struct exception_table_entry *search_module_extables(unsigned long addr)
2028{
2029 unsigned long flags;
2030 const struct exception_table_entry *e = NULL;
2031 struct module *mod;
2032
2033 spin_lock_irqsave(&modlist_lock, flags);
2034 list_for_each_entry(mod, &modules, list) {
2035 if (mod->num_exentries == 0)
2036 continue;
2037
2038 e = search_extable(mod->extable,
2039 mod->extable + mod->num_exentries - 1,
2040 addr);
2041 if (e)
2042 break;
2043 }
2044 spin_unlock_irqrestore(&modlist_lock, flags);
2045
2046 /* Now, if we found one, we are running inside it now, hence
2047 we cannot unload the module, hence no refcnt needed. */
2048 return e;
2049}
2050
2051/* Is this a valid kernel address? We don't grab the lock: we are oopsing. */
2052struct module *__module_text_address(unsigned long addr)
2053{
2054 struct module *mod;
2055
2056 list_for_each_entry(mod, &modules, list)
2057 if (within(addr, mod->module_init, mod->init_text_size)
2058 || within(addr, mod->module_core, mod->core_text_size))
2059 return mod;
2060 return NULL;
2061}
2062
2063struct module *module_text_address(unsigned long addr)
2064{
2065 struct module *mod;
2066 unsigned long flags;
2067
2068 spin_lock_irqsave(&modlist_lock, flags);
2069 mod = __module_text_address(addr);
2070 spin_unlock_irqrestore(&modlist_lock, flags);
2071
2072 return mod;
2073}
2074
2075/* Don't grab lock, we're oopsing. */
2076void print_modules(void)
2077{
2078 struct module *mod;
2079
2080 printk("Modules linked in:");
2081 list_for_each_entry(mod, &modules, list)
2082 printk(" %s", mod->name);
2083 printk("\n");
2084}
2085
2086void module_add_driver(struct module *mod, struct device_driver *drv)
2087{
2088 if (!mod || !drv)
2089 return;
2090
2091 /* Don't check return code; this call is idempotent */
2092 sysfs_create_link(&drv->kobj, &mod->mkobj.kobj, "module");
2093}
2094EXPORT_SYMBOL(module_add_driver);
2095
2096void module_remove_driver(struct device_driver *drv)
2097{
2098 if (!drv)
2099 return;
2100 sysfs_remove_link(&drv->kobj, "module");
2101}
2102EXPORT_SYMBOL(module_remove_driver);
2103
2104#ifdef CONFIG_MODVERSIONS
2105/* Generate the signature for struct module here, too, for modversions. */
2106void struct_module(struct module *mod) { return; }
2107EXPORT_SYMBOL(struct_module);
2108#endif
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-07 03:37:03 -0500