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Merge branch 'tip/perf/urgent-2' of git://git.kernel.org/pub/scm/linux/kernel/git...
[linux-2.6-block.git] / kernel / module.c
... / ...
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1/*
2 Copyright (C) 2002 Richard Henderson
3 Copyright (C) 2001 Rusty Russell, 2002, 2010 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/export.h>
20#include <linux/moduleloader.h>
21#include <linux/ftrace_event.h>
22#include <linux/init.h>
23#include <linux/kallsyms.h>
24#include <linux/fs.h>
25#include <linux/sysfs.h>
26#include <linux/kernel.h>
27#include <linux/slab.h>
28#include <linux/vmalloc.h>
29#include <linux/elf.h>
30#include <linux/proc_fs.h>
31#include <linux/seq_file.h>
32#include <linux/syscalls.h>
33#include <linux/fcntl.h>
34#include <linux/rcupdate.h>
35#include <linux/capability.h>
36#include <linux/cpu.h>
37#include <linux/moduleparam.h>
38#include <linux/errno.h>
39#include <linux/err.h>
40#include <linux/vermagic.h>
41#include <linux/notifier.h>
42#include <linux/sched.h>
43#include <linux/stop_machine.h>
44#include <linux/device.h>
45#include <linux/string.h>
46#include <linux/mutex.h>
47#include <linux/rculist.h>
48#include <asm/uaccess.h>
49#include <asm/cacheflush.h>
50#include <asm/mmu_context.h>
51#include <linux/license.h>
52#include <asm/sections.h>
53#include <linux/tracepoint.h>
54#include <linux/ftrace.h>
55#include <linux/async.h>
56#include <linux/percpu.h>
57#include <linux/kmemleak.h>
58#include <linux/jump_label.h>
59#include <linux/pfn.h>
60#include <linux/bsearch.h>
61
62#define CREATE_TRACE_POINTS
63#include <trace/events/module.h>
64
65#if 0
66#define DEBUGP printk
67#else
68#define DEBUGP(fmt , a...)
69#endif
70
71#ifndef ARCH_SHF_SMALL
72#define ARCH_SHF_SMALL 0
73#endif
74
75/*
76 * Modules' sections will be aligned on page boundaries
77 * to ensure complete separation of code and data, but
78 * only when CONFIG_DEBUG_SET_MODULE_RONX=y
79 */
80#ifdef CONFIG_DEBUG_SET_MODULE_RONX
81# define debug_align(X) ALIGN(X, PAGE_SIZE)
82#else
83# define debug_align(X) (X)
84#endif
85
86/*
87 * Given BASE and SIZE this macro calculates the number of pages the
88 * memory regions occupies
89 */
90#define MOD_NUMBER_OF_PAGES(BASE, SIZE) (((SIZE) > 0) ? \
91 (PFN_DOWN((unsigned long)(BASE) + (SIZE) - 1) - \
92 PFN_DOWN((unsigned long)BASE) + 1) \
93 : (0UL))
94
95/* If this is set, the section belongs in the init part of the module */
96#define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
97
98/*
99 * Mutex protects:
100 * 1) List of modules (also safely readable with preempt_disable),
101 * 2) module_use links,
102 * 3) module_addr_min/module_addr_max.
103 * (delete uses stop_machine/add uses RCU list operations). */
104DEFINE_MUTEX(module_mutex);
105EXPORT_SYMBOL_GPL(module_mutex);
106static LIST_HEAD(modules);
107#ifdef CONFIG_KGDB_KDB
108struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
109#endif /* CONFIG_KGDB_KDB */
110
111
112/* Block module loading/unloading? */
113int modules_disabled = 0;
114
115/* Waiting for a module to finish initializing? */
116static DECLARE_WAIT_QUEUE_HEAD(module_wq);
117
118static BLOCKING_NOTIFIER_HEAD(module_notify_list);
119
120/* Bounds of module allocation, for speeding __module_address.
121 * Protected by module_mutex. */
122static unsigned long module_addr_min = -1UL, module_addr_max = 0;
123
124int register_module_notifier(struct notifier_block * nb)
125{
126 return blocking_notifier_chain_register(&module_notify_list, nb);
127}
128EXPORT_SYMBOL(register_module_notifier);
129
130int unregister_module_notifier(struct notifier_block * nb)
131{
132 return blocking_notifier_chain_unregister(&module_notify_list, nb);
133}
134EXPORT_SYMBOL(unregister_module_notifier);
135
136struct load_info {
137 Elf_Ehdr *hdr;
138 unsigned long len;
139 Elf_Shdr *sechdrs;
140 char *secstrings, *strtab;
141 unsigned long *strmap;
142 unsigned long symoffs, stroffs;
143 struct _ddebug *debug;
144 unsigned int num_debug;
145 struct {
146 unsigned int sym, str, mod, vers, info, pcpu;
147 } index;
148};
149
150/* We require a truly strong try_module_get(): 0 means failure due to
151 ongoing or failed initialization etc. */
152static inline int strong_try_module_get(struct module *mod)
153{
154 if (mod && mod->state == MODULE_STATE_COMING)
155 return -EBUSY;
156 if (try_module_get(mod))
157 return 0;
158 else
159 return -ENOENT;
160}
161
162static inline void add_taint_module(struct module *mod, unsigned flag)
163{
164 add_taint(flag);
165 mod->taints |= (1U << flag);
166}
167
168/*
169 * A thread that wants to hold a reference to a module only while it
170 * is running can call this to safely exit. nfsd and lockd use this.
171 */
172void __module_put_and_exit(struct module *mod, long code)
173{
174 module_put(mod);
175 do_exit(code);
176}
177EXPORT_SYMBOL(__module_put_and_exit);
178
179/* Find a module section: 0 means not found. */
180static unsigned int find_sec(const struct load_info *info, const char *name)
181{
182 unsigned int i;
183
184 for (i = 1; i < info->hdr->e_shnum; i++) {
185 Elf_Shdr *shdr = &info->sechdrs[i];
186 /* Alloc bit cleared means "ignore it." */
187 if ((shdr->sh_flags & SHF_ALLOC)
188 && strcmp(info->secstrings + shdr->sh_name, name) == 0)
189 return i;
190 }
191 return 0;
192}
193
194/* Find a module section, or NULL. */
195static void *section_addr(const struct load_info *info, const char *name)
196{
197 /* Section 0 has sh_addr 0. */
198 return (void *)info->sechdrs[find_sec(info, name)].sh_addr;
199}
200
201/* Find a module section, or NULL. Fill in number of "objects" in section. */
202static void *section_objs(const struct load_info *info,
203 const char *name,
204 size_t object_size,
205 unsigned int *num)
206{
207 unsigned int sec = find_sec(info, name);
208
209 /* Section 0 has sh_addr 0 and sh_size 0. */
210 *num = info->sechdrs[sec].sh_size / object_size;
211 return (void *)info->sechdrs[sec].sh_addr;
212}
213
214/* Provided by the linker */
215extern const struct kernel_symbol __start___ksymtab[];
216extern const struct kernel_symbol __stop___ksymtab[];
217extern const struct kernel_symbol __start___ksymtab_gpl[];
218extern const struct kernel_symbol __stop___ksymtab_gpl[];
219extern const struct kernel_symbol __start___ksymtab_gpl_future[];
220extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
221extern const unsigned long __start___kcrctab[];
222extern const unsigned long __start___kcrctab_gpl[];
223extern const unsigned long __start___kcrctab_gpl_future[];
224#ifdef CONFIG_UNUSED_SYMBOLS
225extern const struct kernel_symbol __start___ksymtab_unused[];
226extern const struct kernel_symbol __stop___ksymtab_unused[];
227extern const struct kernel_symbol __start___ksymtab_unused_gpl[];
228extern const struct kernel_symbol __stop___ksymtab_unused_gpl[];
229extern const unsigned long __start___kcrctab_unused[];
230extern const unsigned long __start___kcrctab_unused_gpl[];
231#endif
232
233#ifndef CONFIG_MODVERSIONS
234#define symversion(base, idx) NULL
235#else
236#define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
237#endif
238
239static bool each_symbol_in_section(const struct symsearch *arr,
240 unsigned int arrsize,
241 struct module *owner,
242 bool (*fn)(const struct symsearch *syms,
243 struct module *owner,
244 void *data),
245 void *data)
246{
247 unsigned int j;
248
249 for (j = 0; j < arrsize; j++) {
250 if (fn(&arr[j], owner, data))
251 return true;
252 }
253
254 return false;
255}
256
257/* Returns true as soon as fn returns true, otherwise false. */
258bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
259 struct module *owner,
260 void *data),
261 void *data)
262{
263 struct module *mod;
264 static const struct symsearch arr[] = {
265 { __start___ksymtab, __stop___ksymtab, __start___kcrctab,
266 NOT_GPL_ONLY, false },
267 { __start___ksymtab_gpl, __stop___ksymtab_gpl,
268 __start___kcrctab_gpl,
269 GPL_ONLY, false },
270 { __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future,
271 __start___kcrctab_gpl_future,
272 WILL_BE_GPL_ONLY, false },
273#ifdef CONFIG_UNUSED_SYMBOLS
274 { __start___ksymtab_unused, __stop___ksymtab_unused,
275 __start___kcrctab_unused,
276 NOT_GPL_ONLY, true },
277 { __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl,
278 __start___kcrctab_unused_gpl,
279 GPL_ONLY, true },
280#endif
281 };
282
283 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data))
284 return true;
285
286 list_for_each_entry_rcu(mod, &modules, list) {
287 struct symsearch arr[] = {
288 { mod->syms, mod->syms + mod->num_syms, mod->crcs,
289 NOT_GPL_ONLY, false },
290 { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
291 mod->gpl_crcs,
292 GPL_ONLY, false },
293 { mod->gpl_future_syms,
294 mod->gpl_future_syms + mod->num_gpl_future_syms,
295 mod->gpl_future_crcs,
296 WILL_BE_GPL_ONLY, false },
297#ifdef CONFIG_UNUSED_SYMBOLS
298 { mod->unused_syms,
299 mod->unused_syms + mod->num_unused_syms,
300 mod->unused_crcs,
301 NOT_GPL_ONLY, true },
302 { mod->unused_gpl_syms,
303 mod->unused_gpl_syms + mod->num_unused_gpl_syms,
304 mod->unused_gpl_crcs,
305 GPL_ONLY, true },
306#endif
307 };
308
309 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data))
310 return true;
311 }
312 return false;
313}
314EXPORT_SYMBOL_GPL(each_symbol_section);
315
316struct find_symbol_arg {
317 /* Input */
318 const char *name;
319 bool gplok;
320 bool warn;
321
322 /* Output */
323 struct module *owner;
324 const unsigned long *crc;
325 const struct kernel_symbol *sym;
326};
327
328static bool check_symbol(const struct symsearch *syms,
329 struct module *owner,
330 unsigned int symnum, void *data)
331{
332 struct find_symbol_arg *fsa = data;
333
334 if (!fsa->gplok) {
335 if (syms->licence == GPL_ONLY)
336 return false;
337 if (syms->licence == WILL_BE_GPL_ONLY && fsa->warn) {
338 printk(KERN_WARNING "Symbol %s is being used "
339 "by a non-GPL module, which will not "
340 "be allowed in the future\n", fsa->name);
341 printk(KERN_WARNING "Please see the file "
342 "Documentation/feature-removal-schedule.txt "
343 "in the kernel source tree for more details.\n");
344 }
345 }
346
347#ifdef CONFIG_UNUSED_SYMBOLS
348 if (syms->unused && fsa->warn) {
349 printk(KERN_WARNING "Symbol %s is marked as UNUSED, "
350 "however this module is using it.\n", fsa->name);
351 printk(KERN_WARNING
352 "This symbol will go away in the future.\n");
353 printk(KERN_WARNING
354 "Please evalute if this is the right api to use and if "
355 "it really is, submit a report the linux kernel "
356 "mailinglist together with submitting your code for "
357 "inclusion.\n");
358 }
359#endif
360
361 fsa->owner = owner;
362 fsa->crc = symversion(syms->crcs, symnum);
363 fsa->sym = &syms->start[symnum];
364 return true;
365}
366
367static int cmp_name(const void *va, const void *vb)
368{
369 const char *a;
370 const struct kernel_symbol *b;
371 a = va; b = vb;
372 return strcmp(a, b->name);
373}
374
375static bool find_symbol_in_section(const struct symsearch *syms,
376 struct module *owner,
377 void *data)
378{
379 struct find_symbol_arg *fsa = data;
380 struct kernel_symbol *sym;
381
382 sym = bsearch(fsa->name, syms->start, syms->stop - syms->start,
383 sizeof(struct kernel_symbol), cmp_name);
384
385 if (sym != NULL && check_symbol(syms, owner, sym - syms->start, data))
386 return true;
387
388 return false;
389}
390
391/* Find a symbol and return it, along with, (optional) crc and
392 * (optional) module which owns it. Needs preempt disabled or module_mutex. */
393const struct kernel_symbol *find_symbol(const char *name,
394 struct module **owner,
395 const unsigned long **crc,
396 bool gplok,
397 bool warn)
398{
399 struct find_symbol_arg fsa;
400
401 fsa.name = name;
402 fsa.gplok = gplok;
403 fsa.warn = warn;
404
405 if (each_symbol_section(find_symbol_in_section, &fsa)) {
406 if (owner)
407 *owner = fsa.owner;
408 if (crc)
409 *crc = fsa.crc;
410 return fsa.sym;
411 }
412
413 DEBUGP("Failed to find symbol %s\n", name);
414 return NULL;
415}
416EXPORT_SYMBOL_GPL(find_symbol);
417
418/* Search for module by name: must hold module_mutex. */
419struct module *find_module(const char *name)
420{
421 struct module *mod;
422
423 list_for_each_entry(mod, &modules, list) {
424 if (strcmp(mod->name, name) == 0)
425 return mod;
426 }
427 return NULL;
428}
429EXPORT_SYMBOL_GPL(find_module);
430
431#ifdef CONFIG_SMP
432
433static inline void __percpu *mod_percpu(struct module *mod)
434{
435 return mod->percpu;
436}
437
438static int percpu_modalloc(struct module *mod,
439 unsigned long size, unsigned long align)
440{
441 if (align > PAGE_SIZE) {
442 printk(KERN_WARNING "%s: per-cpu alignment %li > %li\n",
443 mod->name, align, PAGE_SIZE);
444 align = PAGE_SIZE;
445 }
446
447 mod->percpu = __alloc_reserved_percpu(size, align);
448 if (!mod->percpu) {
449 printk(KERN_WARNING
450 "%s: Could not allocate %lu bytes percpu data\n",
451 mod->name, size);
452 return -ENOMEM;
453 }
454 mod->percpu_size = size;
455 return 0;
456}
457
458static void percpu_modfree(struct module *mod)
459{
460 free_percpu(mod->percpu);
461}
462
463static unsigned int find_pcpusec(struct load_info *info)
464{
465 return find_sec(info, ".data..percpu");
466}
467
468static void percpu_modcopy(struct module *mod,
469 const void *from, unsigned long size)
470{
471 int cpu;
472
473 for_each_possible_cpu(cpu)
474 memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
475}
476
477/**
478 * is_module_percpu_address - test whether address is from module static percpu
479 * @addr: address to test
480 *
481 * Test whether @addr belongs to module static percpu area.
482 *
483 * RETURNS:
484 * %true if @addr is from module static percpu area
485 */
486bool is_module_percpu_address(unsigned long addr)
487{
488 struct module *mod;
489 unsigned int cpu;
490
491 preempt_disable();
492
493 list_for_each_entry_rcu(mod, &modules, list) {
494 if (!mod->percpu_size)
495 continue;
496 for_each_possible_cpu(cpu) {
497 void *start = per_cpu_ptr(mod->percpu, cpu);
498
499 if ((void *)addr >= start &&
500 (void *)addr < start + mod->percpu_size) {
501 preempt_enable();
502 return true;
503 }
504 }
505 }
506
507 preempt_enable();
508 return false;
509}
510
511#else /* ... !CONFIG_SMP */
512
513static inline void __percpu *mod_percpu(struct module *mod)
514{
515 return NULL;
516}
517static inline int percpu_modalloc(struct module *mod,
518 unsigned long size, unsigned long align)
519{
520 return -ENOMEM;
521}
522static inline void percpu_modfree(struct module *mod)
523{
524}
525static unsigned int find_pcpusec(struct load_info *info)
526{
527 return 0;
528}
529static inline void percpu_modcopy(struct module *mod,
530 const void *from, unsigned long size)
531{
532 /* pcpusec should be 0, and size of that section should be 0. */
533 BUG_ON(size != 0);
534}
535bool is_module_percpu_address(unsigned long addr)
536{
537 return false;
538}
539
540#endif /* CONFIG_SMP */
541
542#define MODINFO_ATTR(field) \
543static void setup_modinfo_##field(struct module *mod, const char *s) \
544{ \
545 mod->field = kstrdup(s, GFP_KERNEL); \
546} \
547static ssize_t show_modinfo_##field(struct module_attribute *mattr, \
548 struct module_kobject *mk, char *buffer) \
549{ \
550 return sprintf(buffer, "%s\n", mk->mod->field); \
551} \
552static int modinfo_##field##_exists(struct module *mod) \
553{ \
554 return mod->field != NULL; \
555} \
556static void free_modinfo_##field(struct module *mod) \
557{ \
558 kfree(mod->field); \
559 mod->field = NULL; \
560} \
561static struct module_attribute modinfo_##field = { \
562 .attr = { .name = __stringify(field), .mode = 0444 }, \
563 .show = show_modinfo_##field, \
564 .setup = setup_modinfo_##field, \
565 .test = modinfo_##field##_exists, \
566 .free = free_modinfo_##field, \
567};
568
569MODINFO_ATTR(version);
570MODINFO_ATTR(srcversion);
571
572static char last_unloaded_module[MODULE_NAME_LEN+1];
573
574#ifdef CONFIG_MODULE_UNLOAD
575
576EXPORT_TRACEPOINT_SYMBOL(module_get);
577
578/* Init the unload section of the module. */
579static int module_unload_init(struct module *mod)
580{
581 mod->refptr = alloc_percpu(struct module_ref);
582 if (!mod->refptr)
583 return -ENOMEM;
584
585 INIT_LIST_HEAD(&mod->source_list);
586 INIT_LIST_HEAD(&mod->target_list);
587
588 /* Hold reference count during initialization. */
589 __this_cpu_write(mod->refptr->incs, 1);
590 /* Backwards compatibility macros put refcount during init. */
591 mod->waiter = current;
592
593 return 0;
594}
595
596/* Does a already use b? */
597static int already_uses(struct module *a, struct module *b)
598{
599 struct module_use *use;
600
601 list_for_each_entry(use, &b->source_list, source_list) {
602 if (use->source == a) {
603 DEBUGP("%s uses %s!\n", a->name, b->name);
604 return 1;
605 }
606 }
607 DEBUGP("%s does not use %s!\n", a->name, b->name);
608 return 0;
609}
610
611/*
612 * Module a uses b
613 * - we add 'a' as a "source", 'b' as a "target" of module use
614 * - the module_use is added to the list of 'b' sources (so
615 * 'b' can walk the list to see who sourced them), and of 'a'
616 * targets (so 'a' can see what modules it targets).
617 */
618static int add_module_usage(struct module *a, struct module *b)
619{
620 struct module_use *use;
621
622 DEBUGP("Allocating new usage for %s.\n", a->name);
623 use = kmalloc(sizeof(*use), GFP_ATOMIC);
624 if (!use) {
625 printk(KERN_WARNING "%s: out of memory loading\n", a->name);
626 return -ENOMEM;
627 }
628
629 use->source = a;
630 use->target = b;
631 list_add(&use->source_list, &b->source_list);
632 list_add(&use->target_list, &a->target_list);
633 return 0;
634}
635
636/* Module a uses b: caller needs module_mutex() */
637int ref_module(struct module *a, struct module *b)
638{
639 int err;
640
641 if (b == NULL || already_uses(a, b))
642 return 0;
643
644 /* If module isn't available, we fail. */
645 err = strong_try_module_get(b);
646 if (err)
647 return err;
648
649 err = add_module_usage(a, b);
650 if (err) {
651 module_put(b);
652 return err;
653 }
654 return 0;
655}
656EXPORT_SYMBOL_GPL(ref_module);
657
658/* Clear the unload stuff of the module. */
659static void module_unload_free(struct module *mod)
660{
661 struct module_use *use, *tmp;
662
663 mutex_lock(&module_mutex);
664 list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
665 struct module *i = use->target;
666 DEBUGP("%s unusing %s\n", mod->name, i->name);
667 module_put(i);
668 list_del(&use->source_list);
669 list_del(&use->target_list);
670 kfree(use);
671 }
672 mutex_unlock(&module_mutex);
673
674 free_percpu(mod->refptr);
675}
676
677#ifdef CONFIG_MODULE_FORCE_UNLOAD
678static inline int try_force_unload(unsigned int flags)
679{
680 int ret = (flags & O_TRUNC);
681 if (ret)
682 add_taint(TAINT_FORCED_RMMOD);
683 return ret;
684}
685#else
686static inline int try_force_unload(unsigned int flags)
687{
688 return 0;
689}
690#endif /* CONFIG_MODULE_FORCE_UNLOAD */
691
692struct stopref
693{
694 struct module *mod;
695 int flags;
696 int *forced;
697};
698
699/* Whole machine is stopped with interrupts off when this runs. */
700static int __try_stop_module(void *_sref)
701{
702 struct stopref *sref = _sref;
703
704 /* If it's not unused, quit unless we're forcing. */
705 if (module_refcount(sref->mod) != 0) {
706 if (!(*sref->forced = try_force_unload(sref->flags)))
707 return -EWOULDBLOCK;
708 }
709
710 /* Mark it as dying. */
711 sref->mod->state = MODULE_STATE_GOING;
712 return 0;
713}
714
715static int try_stop_module(struct module *mod, int flags, int *forced)
716{
717 if (flags & O_NONBLOCK) {
718 struct stopref sref = { mod, flags, forced };
719
720 return stop_machine(__try_stop_module, &sref, NULL);
721 } else {
722 /* We don't need to stop the machine for this. */
723 mod->state = MODULE_STATE_GOING;
724 synchronize_sched();
725 return 0;
726 }
727}
728
729unsigned int module_refcount(struct module *mod)
730{
731 unsigned int incs = 0, decs = 0;
732 int cpu;
733
734 for_each_possible_cpu(cpu)
735 decs += per_cpu_ptr(mod->refptr, cpu)->decs;
736 /*
737 * ensure the incs are added up after the decs.
738 * module_put ensures incs are visible before decs with smp_wmb.
739 *
740 * This 2-count scheme avoids the situation where the refcount
741 * for CPU0 is read, then CPU0 increments the module refcount,
742 * then CPU1 drops that refcount, then the refcount for CPU1 is
743 * read. We would record a decrement but not its corresponding
744 * increment so we would see a low count (disaster).
745 *
746 * Rare situation? But module_refcount can be preempted, and we
747 * might be tallying up 4096+ CPUs. So it is not impossible.
748 */
749 smp_rmb();
750 for_each_possible_cpu(cpu)
751 incs += per_cpu_ptr(mod->refptr, cpu)->incs;
752 return incs - decs;
753}
754EXPORT_SYMBOL(module_refcount);
755
756/* This exists whether we can unload or not */
757static void free_module(struct module *mod);
758
759static void wait_for_zero_refcount(struct module *mod)
760{
761 /* Since we might sleep for some time, release the mutex first */
762 mutex_unlock(&module_mutex);
763 for (;;) {
764 DEBUGP("Looking at refcount...\n");
765 set_current_state(TASK_UNINTERRUPTIBLE);
766 if (module_refcount(mod) == 0)
767 break;
768 schedule();
769 }
770 current->state = TASK_RUNNING;
771 mutex_lock(&module_mutex);
772}
773
774SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
775 unsigned int, flags)
776{
777 struct module *mod;
778 char name[MODULE_NAME_LEN];
779 int ret, forced = 0;
780
781 if (!capable(CAP_SYS_MODULE) || modules_disabled)
782 return -EPERM;
783
784 if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
785 return -EFAULT;
786 name[MODULE_NAME_LEN-1] = '\0';
787
788 if (mutex_lock_interruptible(&module_mutex) != 0)
789 return -EINTR;
790
791 mod = find_module(name);
792 if (!mod) {
793 ret = -ENOENT;
794 goto out;
795 }
796
797 if (!list_empty(&mod->source_list)) {
798 /* Other modules depend on us: get rid of them first. */
799 ret = -EWOULDBLOCK;
800 goto out;
801 }
802
803 /* Doing init or already dying? */
804 if (mod->state != MODULE_STATE_LIVE) {
805 /* FIXME: if (force), slam module count and wake up
806 waiter --RR */
807 DEBUGP("%s already dying\n", mod->name);
808 ret = -EBUSY;
809 goto out;
810 }
811
812 /* If it has an init func, it must have an exit func to unload */
813 if (mod->init && !mod->exit) {
814 forced = try_force_unload(flags);
815 if (!forced) {
816 /* This module can't be removed */
817 ret = -EBUSY;
818 goto out;
819 }
820 }
821
822 /* Set this up before setting mod->state */
823 mod->waiter = current;
824
825 /* Stop the machine so refcounts can't move and disable module. */
826 ret = try_stop_module(mod, flags, &forced);
827 if (ret != 0)
828 goto out;
829
830 /* Never wait if forced. */
831 if (!forced && module_refcount(mod) != 0)
832 wait_for_zero_refcount(mod);
833
834 mutex_unlock(&module_mutex);
835 /* Final destruction now no one is using it. */
836 if (mod->exit != NULL)
837 mod->exit();
838 blocking_notifier_call_chain(&module_notify_list,
839 MODULE_STATE_GOING, mod);
840 async_synchronize_full();
841
842 /* Store the name of the last unloaded module for diagnostic purposes */
843 strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
844
845 free_module(mod);
846 return 0;
847out:
848 mutex_unlock(&module_mutex);
849 return ret;
850}
851
852static inline void print_unload_info(struct seq_file *m, struct module *mod)
853{
854 struct module_use *use;
855 int printed_something = 0;
856
857 seq_printf(m, " %u ", module_refcount(mod));
858
859 /* Always include a trailing , so userspace can differentiate
860 between this and the old multi-field proc format. */
861 list_for_each_entry(use, &mod->source_list, source_list) {
862 printed_something = 1;
863 seq_printf(m, "%s,", use->source->name);
864 }
865
866 if (mod->init != NULL && mod->exit == NULL) {
867 printed_something = 1;
868 seq_printf(m, "[permanent],");
869 }
870
871 if (!printed_something)
872 seq_printf(m, "-");
873}
874
875void __symbol_put(const char *symbol)
876{
877 struct module *owner;
878
879 preempt_disable();
880 if (!find_symbol(symbol, &owner, NULL, true, false))
881 BUG();
882 module_put(owner);
883 preempt_enable();
884}
885EXPORT_SYMBOL(__symbol_put);
886
887/* Note this assumes addr is a function, which it currently always is. */
888void symbol_put_addr(void *addr)
889{
890 struct module *modaddr;
891 unsigned long a = (unsigned long)dereference_function_descriptor(addr);
892
893 if (core_kernel_text(a))
894 return;
895
896 /* module_text_address is safe here: we're supposed to have reference
897 * to module from symbol_get, so it can't go away. */
898 modaddr = __module_text_address(a);
899 BUG_ON(!modaddr);
900 module_put(modaddr);
901}
902EXPORT_SYMBOL_GPL(symbol_put_addr);
903
904static ssize_t show_refcnt(struct module_attribute *mattr,
905 struct module_kobject *mk, char *buffer)
906{
907 return sprintf(buffer, "%u\n", module_refcount(mk->mod));
908}
909
910static struct module_attribute refcnt = {
911 .attr = { .name = "refcnt", .mode = 0444 },
912 .show = show_refcnt,
913};
914
915void module_put(struct module *module)
916{
917 if (module) {
918 preempt_disable();
919 smp_wmb(); /* see comment in module_refcount */
920 __this_cpu_inc(module->refptr->decs);
921
922 trace_module_put(module, _RET_IP_);
923 /* Maybe they're waiting for us to drop reference? */
924 if (unlikely(!module_is_live(module)))
925 wake_up_process(module->waiter);
926 preempt_enable();
927 }
928}
929EXPORT_SYMBOL(module_put);
930
931#else /* !CONFIG_MODULE_UNLOAD */
932static inline void print_unload_info(struct seq_file *m, struct module *mod)
933{
934 /* We don't know the usage count, or what modules are using. */
935 seq_printf(m, " - -");
936}
937
938static inline void module_unload_free(struct module *mod)
939{
940}
941
942int ref_module(struct module *a, struct module *b)
943{
944 return strong_try_module_get(b);
945}
946EXPORT_SYMBOL_GPL(ref_module);
947
948static inline int module_unload_init(struct module *mod)
949{
950 return 0;
951}
952#endif /* CONFIG_MODULE_UNLOAD */
953
954static ssize_t show_initstate(struct module_attribute *mattr,
955 struct module_kobject *mk, char *buffer)
956{
957 const char *state = "unknown";
958
959 switch (mk->mod->state) {
960 case MODULE_STATE_LIVE:
961 state = "live";
962 break;
963 case MODULE_STATE_COMING:
964 state = "coming";
965 break;
966 case MODULE_STATE_GOING:
967 state = "going";
968 break;
969 }
970 return sprintf(buffer, "%s\n", state);
971}
972
973static struct module_attribute initstate = {
974 .attr = { .name = "initstate", .mode = 0444 },
975 .show = show_initstate,
976};
977
978static ssize_t store_uevent(struct module_attribute *mattr,
979 struct module_kobject *mk,
980 const char *buffer, size_t count)
981{
982 enum kobject_action action;
983
984 if (kobject_action_type(buffer, count, &action) == 0)
985 kobject_uevent(&mk->kobj, action);
986 return count;
987}
988
989struct module_attribute module_uevent = {
990 .attr = { .name = "uevent", .mode = 0200 },
991 .store = store_uevent,
992};
993
994static struct module_attribute *modinfo_attrs[] = {
995 &modinfo_version,
996 &modinfo_srcversion,
997 &initstate,
998 &module_uevent,
999#ifdef CONFIG_MODULE_UNLOAD
1000 &refcnt,
1001#endif
1002 NULL,
1003};
1004
1005static const char vermagic[] = VERMAGIC_STRING;
1006
1007static int try_to_force_load(struct module *mod, const char *reason)
1008{
1009#ifdef CONFIG_MODULE_FORCE_LOAD
1010 if (!test_taint(TAINT_FORCED_MODULE))
1011 printk(KERN_WARNING "%s: %s: kernel tainted.\n",
1012 mod->name, reason);
1013 add_taint_module(mod, TAINT_FORCED_MODULE);
1014 return 0;
1015#else
1016 return -ENOEXEC;
1017#endif
1018}
1019
1020#ifdef CONFIG_MODVERSIONS
1021/* If the arch applies (non-zero) relocations to kernel kcrctab, unapply it. */
1022static unsigned long maybe_relocated(unsigned long crc,
1023 const struct module *crc_owner)
1024{
1025#ifdef ARCH_RELOCATES_KCRCTAB
1026 if (crc_owner == NULL)
1027 return crc - (unsigned long)reloc_start;
1028#endif
1029 return crc;
1030}
1031
1032static int check_version(Elf_Shdr *sechdrs,
1033 unsigned int versindex,
1034 const char *symname,
1035 struct module *mod,
1036 const unsigned long *crc,
1037 const struct module *crc_owner)
1038{
1039 unsigned int i, num_versions;
1040 struct modversion_info *versions;
1041
1042 /* Exporting module didn't supply crcs? OK, we're already tainted. */
1043 if (!crc)
1044 return 1;
1045
1046 /* No versions at all? modprobe --force does this. */
1047 if (versindex == 0)
1048 return try_to_force_load(mod, symname) == 0;
1049
1050 versions = (void *) sechdrs[versindex].sh_addr;
1051 num_versions = sechdrs[versindex].sh_size
1052 / sizeof(struct modversion_info);
1053
1054 for (i = 0; i < num_versions; i++) {
1055 if (strcmp(versions[i].name, symname) != 0)
1056 continue;
1057
1058 if (versions[i].crc == maybe_relocated(*crc, crc_owner))
1059 return 1;
1060 DEBUGP("Found checksum %lX vs module %lX\n",
1061 maybe_relocated(*crc, crc_owner), versions[i].crc);
1062 goto bad_version;
1063 }
1064
1065 printk(KERN_WARNING "%s: no symbol version for %s\n",
1066 mod->name, symname);
1067 return 0;
1068
1069bad_version:
1070 printk("%s: disagrees about version of symbol %s\n",
1071 mod->name, symname);
1072 return 0;
1073}
1074
1075static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1076 unsigned int versindex,
1077 struct module *mod)
1078{
1079 const unsigned long *crc;
1080
1081 /* Since this should be found in kernel (which can't be removed),
1082 * no locking is necessary. */
1083 if (!find_symbol(MODULE_SYMBOL_PREFIX "module_layout", NULL,
1084 &crc, true, false))
1085 BUG();
1086 return check_version(sechdrs, versindex, "module_layout", mod, crc,
1087 NULL);
1088}
1089
1090/* First part is kernel version, which we ignore if module has crcs. */
1091static inline int same_magic(const char *amagic, const char *bmagic,
1092 bool has_crcs)
1093{
1094 if (has_crcs) {
1095 amagic += strcspn(amagic, " ");
1096 bmagic += strcspn(bmagic, " ");
1097 }
1098 return strcmp(amagic, bmagic) == 0;
1099}
1100#else
1101static inline int check_version(Elf_Shdr *sechdrs,
1102 unsigned int versindex,
1103 const char *symname,
1104 struct module *mod,
1105 const unsigned long *crc,
1106 const struct module *crc_owner)
1107{
1108 return 1;
1109}
1110
1111static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1112 unsigned int versindex,
1113 struct module *mod)
1114{
1115 return 1;
1116}
1117
1118static inline int same_magic(const char *amagic, const char *bmagic,
1119 bool has_crcs)
1120{
1121 return strcmp(amagic, bmagic) == 0;
1122}
1123#endif /* CONFIG_MODVERSIONS */
1124
1125/* Resolve a symbol for this module. I.e. if we find one, record usage. */
1126static const struct kernel_symbol *resolve_symbol(struct module *mod,
1127 const struct load_info *info,
1128 const char *name,
1129 char ownername[])
1130{
1131 struct module *owner;
1132 const struct kernel_symbol *sym;
1133 const unsigned long *crc;
1134 int err;
1135
1136 mutex_lock(&module_mutex);
1137 sym = find_symbol(name, &owner, &crc,
1138 !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
1139 if (!sym)
1140 goto unlock;
1141
1142 if (!check_version(info->sechdrs, info->index.vers, name, mod, crc,
1143 owner)) {
1144 sym = ERR_PTR(-EINVAL);
1145 goto getname;
1146 }
1147
1148 err = ref_module(mod, owner);
1149 if (err) {
1150 sym = ERR_PTR(err);
1151 goto getname;
1152 }
1153
1154getname:
1155 /* We must make copy under the lock if we failed to get ref. */
1156 strncpy(ownername, module_name(owner), MODULE_NAME_LEN);
1157unlock:
1158 mutex_unlock(&module_mutex);
1159 return sym;
1160}
1161
1162static const struct kernel_symbol *
1163resolve_symbol_wait(struct module *mod,
1164 const struct load_info *info,
1165 const char *name)
1166{
1167 const struct kernel_symbol *ksym;
1168 char owner[MODULE_NAME_LEN];
1169
1170 if (wait_event_interruptible_timeout(module_wq,
1171 !IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
1172 || PTR_ERR(ksym) != -EBUSY,
1173 30 * HZ) <= 0) {
1174 printk(KERN_WARNING "%s: gave up waiting for init of module %s.\n",
1175 mod->name, owner);
1176 }
1177 return ksym;
1178}
1179
1180/*
1181 * /sys/module/foo/sections stuff
1182 * J. Corbet <corbet@lwn.net>
1183 */
1184#ifdef CONFIG_SYSFS
1185
1186#ifdef CONFIG_KALLSYMS
1187static inline bool sect_empty(const Elf_Shdr *sect)
1188{
1189 return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
1190}
1191
1192struct module_sect_attr
1193{
1194 struct module_attribute mattr;
1195 char *name;
1196 unsigned long address;
1197};
1198
1199struct module_sect_attrs
1200{
1201 struct attribute_group grp;
1202 unsigned int nsections;
1203 struct module_sect_attr attrs[0];
1204};
1205
1206static ssize_t module_sect_show(struct module_attribute *mattr,
1207 struct module_kobject *mk, char *buf)
1208{
1209 struct module_sect_attr *sattr =
1210 container_of(mattr, struct module_sect_attr, mattr);
1211 return sprintf(buf, "0x%pK\n", (void *)sattr->address);
1212}
1213
1214static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
1215{
1216 unsigned int section;
1217
1218 for (section = 0; section < sect_attrs->nsections; section++)
1219 kfree(sect_attrs->attrs[section].name);
1220 kfree(sect_attrs);
1221}
1222
1223static void add_sect_attrs(struct module *mod, const struct load_info *info)
1224{
1225 unsigned int nloaded = 0, i, size[2];
1226 struct module_sect_attrs *sect_attrs;
1227 struct module_sect_attr *sattr;
1228 struct attribute **gattr;
1229
1230 /* Count loaded sections and allocate structures */
1231 for (i = 0; i < info->hdr->e_shnum; i++)
1232 if (!sect_empty(&info->sechdrs[i]))
1233 nloaded++;
1234 size[0] = ALIGN(sizeof(*sect_attrs)
1235 + nloaded * sizeof(sect_attrs->attrs[0]),
1236 sizeof(sect_attrs->grp.attrs[0]));
1237 size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]);
1238 sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
1239 if (sect_attrs == NULL)
1240 return;
1241
1242 /* Setup section attributes. */
1243 sect_attrs->grp.name = "sections";
1244 sect_attrs->grp.attrs = (void *)sect_attrs + size[0];
1245
1246 sect_attrs->nsections = 0;
1247 sattr = &sect_attrs->attrs[0];
1248 gattr = &sect_attrs->grp.attrs[0];
1249 for (i = 0; i < info->hdr->e_shnum; i++) {
1250 Elf_Shdr *sec = &info->sechdrs[i];
1251 if (sect_empty(sec))
1252 continue;
1253 sattr->address = sec->sh_addr;
1254 sattr->name = kstrdup(info->secstrings + sec->sh_name,
1255 GFP_KERNEL);
1256 if (sattr->name == NULL)
1257 goto out;
1258 sect_attrs->nsections++;
1259 sysfs_attr_init(&sattr->mattr.attr);
1260 sattr->mattr.show = module_sect_show;
1261 sattr->mattr.store = NULL;
1262 sattr->mattr.attr.name = sattr->name;
1263 sattr->mattr.attr.mode = S_IRUGO;
1264 *(gattr++) = &(sattr++)->mattr.attr;
1265 }
1266 *gattr = NULL;
1267
1268 if (sysfs_create_group(&mod->mkobj.kobj, &sect_attrs->grp))
1269 goto out;
1270
1271 mod->sect_attrs = sect_attrs;
1272 return;
1273 out:
1274 free_sect_attrs(sect_attrs);
1275}
1276
1277static void remove_sect_attrs(struct module *mod)
1278{
1279 if (mod->sect_attrs) {
1280 sysfs_remove_group(&mod->mkobj.kobj,
1281 &mod->sect_attrs->grp);
1282 /* We are positive that no one is using any sect attrs
1283 * at this point. Deallocate immediately. */
1284 free_sect_attrs(mod->sect_attrs);
1285 mod->sect_attrs = NULL;
1286 }
1287}
1288
1289/*
1290 * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
1291 */
1292
1293struct module_notes_attrs {
1294 struct kobject *dir;
1295 unsigned int notes;
1296 struct bin_attribute attrs[0];
1297};
1298
1299static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
1300 struct bin_attribute *bin_attr,
1301 char *buf, loff_t pos, size_t count)
1302{
1303 /*
1304 * The caller checked the pos and count against our size.
1305 */
1306 memcpy(buf, bin_attr->private + pos, count);
1307 return count;
1308}
1309
1310static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
1311 unsigned int i)
1312{
1313 if (notes_attrs->dir) {
1314 while (i-- > 0)
1315 sysfs_remove_bin_file(notes_attrs->dir,
1316 &notes_attrs->attrs[i]);
1317 kobject_put(notes_attrs->dir);
1318 }
1319 kfree(notes_attrs);
1320}
1321
1322static void add_notes_attrs(struct module *mod, const struct load_info *info)
1323{
1324 unsigned int notes, loaded, i;
1325 struct module_notes_attrs *notes_attrs;
1326 struct bin_attribute *nattr;
1327
1328 /* failed to create section attributes, so can't create notes */
1329 if (!mod->sect_attrs)
1330 return;
1331
1332 /* Count notes sections and allocate structures. */
1333 notes = 0;
1334 for (i = 0; i < info->hdr->e_shnum; i++)
1335 if (!sect_empty(&info->sechdrs[i]) &&
1336 (info->sechdrs[i].sh_type == SHT_NOTE))
1337 ++notes;
1338
1339 if (notes == 0)
1340 return;
1341
1342 notes_attrs = kzalloc(sizeof(*notes_attrs)
1343 + notes * sizeof(notes_attrs->attrs[0]),
1344 GFP_KERNEL);
1345 if (notes_attrs == NULL)
1346 return;
1347
1348 notes_attrs->notes = notes;
1349 nattr = &notes_attrs->attrs[0];
1350 for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
1351 if (sect_empty(&info->sechdrs[i]))
1352 continue;
1353 if (info->sechdrs[i].sh_type == SHT_NOTE) {
1354 sysfs_bin_attr_init(nattr);
1355 nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
1356 nattr->attr.mode = S_IRUGO;
1357 nattr->size = info->sechdrs[i].sh_size;
1358 nattr->private = (void *) info->sechdrs[i].sh_addr;
1359 nattr->read = module_notes_read;
1360 ++nattr;
1361 }
1362 ++loaded;
1363 }
1364
1365 notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
1366 if (!notes_attrs->dir)
1367 goto out;
1368
1369 for (i = 0; i < notes; ++i)
1370 if (sysfs_create_bin_file(notes_attrs->dir,
1371 &notes_attrs->attrs[i]))
1372 goto out;
1373
1374 mod->notes_attrs = notes_attrs;
1375 return;
1376
1377 out:
1378 free_notes_attrs(notes_attrs, i);
1379}
1380
1381static void remove_notes_attrs(struct module *mod)
1382{
1383 if (mod->notes_attrs)
1384 free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
1385}
1386
1387#else
1388
1389static inline void add_sect_attrs(struct module *mod,
1390 const struct load_info *info)
1391{
1392}
1393
1394static inline void remove_sect_attrs(struct module *mod)
1395{
1396}
1397
1398static inline void add_notes_attrs(struct module *mod,
1399 const struct load_info *info)
1400{
1401}
1402
1403static inline void remove_notes_attrs(struct module *mod)
1404{
1405}
1406#endif /* CONFIG_KALLSYMS */
1407
1408static void add_usage_links(struct module *mod)
1409{
1410#ifdef CONFIG_MODULE_UNLOAD
1411 struct module_use *use;
1412 int nowarn;
1413
1414 mutex_lock(&module_mutex);
1415 list_for_each_entry(use, &mod->target_list, target_list) {
1416 nowarn = sysfs_create_link(use->target->holders_dir,
1417 &mod->mkobj.kobj, mod->name);
1418 }
1419 mutex_unlock(&module_mutex);
1420#endif
1421}
1422
1423static void del_usage_links(struct module *mod)
1424{
1425#ifdef CONFIG_MODULE_UNLOAD
1426 struct module_use *use;
1427
1428 mutex_lock(&module_mutex);
1429 list_for_each_entry(use, &mod->target_list, target_list)
1430 sysfs_remove_link(use->target->holders_dir, mod->name);
1431 mutex_unlock(&module_mutex);
1432#endif
1433}
1434
1435static int module_add_modinfo_attrs(struct module *mod)
1436{
1437 struct module_attribute *attr;
1438 struct module_attribute *temp_attr;
1439 int error = 0;
1440 int i;
1441
1442 mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
1443 (ARRAY_SIZE(modinfo_attrs) + 1)),
1444 GFP_KERNEL);
1445 if (!mod->modinfo_attrs)
1446 return -ENOMEM;
1447
1448 temp_attr = mod->modinfo_attrs;
1449 for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
1450 if (!attr->test ||
1451 (attr->test && attr->test(mod))) {
1452 memcpy(temp_attr, attr, sizeof(*temp_attr));
1453 sysfs_attr_init(&temp_attr->attr);
1454 error = sysfs_create_file(&mod->mkobj.kobj,&temp_attr->attr);
1455 ++temp_attr;
1456 }
1457 }
1458 return error;
1459}
1460
1461static void module_remove_modinfo_attrs(struct module *mod)
1462{
1463 struct module_attribute *attr;
1464 int i;
1465
1466 for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
1467 /* pick a field to test for end of list */
1468 if (!attr->attr.name)
1469 break;
1470 sysfs_remove_file(&mod->mkobj.kobj,&attr->attr);
1471 if (attr->free)
1472 attr->free(mod);
1473 }
1474 kfree(mod->modinfo_attrs);
1475}
1476
1477static int mod_sysfs_init(struct module *mod)
1478{
1479 int err;
1480 struct kobject *kobj;
1481
1482 if (!module_sysfs_initialized) {
1483 printk(KERN_ERR "%s: module sysfs not initialized\n",
1484 mod->name);
1485 err = -EINVAL;
1486 goto out;
1487 }
1488
1489 kobj = kset_find_obj(module_kset, mod->name);
1490 if (kobj) {
1491 printk(KERN_ERR "%s: module is already loaded\n", mod->name);
1492 kobject_put(kobj);
1493 err = -EINVAL;
1494 goto out;
1495 }
1496
1497 mod->mkobj.mod = mod;
1498
1499 memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
1500 mod->mkobj.kobj.kset = module_kset;
1501 err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
1502 "%s", mod->name);
1503 if (err)
1504 kobject_put(&mod->mkobj.kobj);
1505
1506 /* delay uevent until full sysfs population */
1507out:
1508 return err;
1509}
1510
1511static int mod_sysfs_setup(struct module *mod,
1512 const struct load_info *info,
1513 struct kernel_param *kparam,
1514 unsigned int num_params)
1515{
1516 int err;
1517
1518 err = mod_sysfs_init(mod);
1519 if (err)
1520 goto out;
1521
1522 mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1523 if (!mod->holders_dir) {
1524 err = -ENOMEM;
1525 goto out_unreg;
1526 }
1527
1528 err = module_param_sysfs_setup(mod, kparam, num_params);
1529 if (err)
1530 goto out_unreg_holders;
1531
1532 err = module_add_modinfo_attrs(mod);
1533 if (err)
1534 goto out_unreg_param;
1535
1536 add_usage_links(mod);
1537 add_sect_attrs(mod, info);
1538 add_notes_attrs(mod, info);
1539
1540 kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
1541 return 0;
1542
1543out_unreg_param:
1544 module_param_sysfs_remove(mod);
1545out_unreg_holders:
1546 kobject_put(mod->holders_dir);
1547out_unreg:
1548 kobject_put(&mod->mkobj.kobj);
1549out:
1550 return err;
1551}
1552
1553static void mod_sysfs_fini(struct module *mod)
1554{
1555 remove_notes_attrs(mod);
1556 remove_sect_attrs(mod);
1557 kobject_put(&mod->mkobj.kobj);
1558}
1559
1560#else /* !CONFIG_SYSFS */
1561
1562static int mod_sysfs_setup(struct module *mod,
1563 const struct load_info *info,
1564 struct kernel_param *kparam,
1565 unsigned int num_params)
1566{
1567 return 0;
1568}
1569
1570static void mod_sysfs_fini(struct module *mod)
1571{
1572}
1573
1574static void module_remove_modinfo_attrs(struct module *mod)
1575{
1576}
1577
1578static void del_usage_links(struct module *mod)
1579{
1580}
1581
1582#endif /* CONFIG_SYSFS */
1583
1584static void mod_sysfs_teardown(struct module *mod)
1585{
1586 del_usage_links(mod);
1587 module_remove_modinfo_attrs(mod);
1588 module_param_sysfs_remove(mod);
1589 kobject_put(mod->mkobj.drivers_dir);
1590 kobject_put(mod->holders_dir);
1591 mod_sysfs_fini(mod);
1592}
1593
1594/*
1595 * unlink the module with the whole machine is stopped with interrupts off
1596 * - this defends against kallsyms not taking locks
1597 */
1598static int __unlink_module(void *_mod)
1599{
1600 struct module *mod = _mod;
1601 list_del(&mod->list);
1602 module_bug_cleanup(mod);
1603 return 0;
1604}
1605
1606#ifdef CONFIG_DEBUG_SET_MODULE_RONX
1607/*
1608 * LKM RO/NX protection: protect module's text/ro-data
1609 * from modification and any data from execution.
1610 */
1611void set_page_attributes(void *start, void *end, int (*set)(unsigned long start, int num_pages))
1612{
1613 unsigned long begin_pfn = PFN_DOWN((unsigned long)start);
1614 unsigned long end_pfn = PFN_DOWN((unsigned long)end);
1615
1616 if (end_pfn > begin_pfn)
1617 set(begin_pfn << PAGE_SHIFT, end_pfn - begin_pfn);
1618}
1619
1620static void set_section_ro_nx(void *base,
1621 unsigned long text_size,
1622 unsigned long ro_size,
1623 unsigned long total_size)
1624{
1625 /* begin and end PFNs of the current subsection */
1626 unsigned long begin_pfn;
1627 unsigned long end_pfn;
1628
1629 /*
1630 * Set RO for module text and RO-data:
1631 * - Always protect first page.
1632 * - Do not protect last partial page.
1633 */
1634 if (ro_size > 0)
1635 set_page_attributes(base, base + ro_size, set_memory_ro);
1636
1637 /*
1638 * Set NX permissions for module data:
1639 * - Do not protect first partial page.
1640 * - Always protect last page.
1641 */
1642 if (total_size > text_size) {
1643 begin_pfn = PFN_UP((unsigned long)base + text_size);
1644 end_pfn = PFN_UP((unsigned long)base + total_size);
1645 if (end_pfn > begin_pfn)
1646 set_memory_nx(begin_pfn << PAGE_SHIFT, end_pfn - begin_pfn);
1647 }
1648}
1649
1650static void unset_module_core_ro_nx(struct module *mod)
1651{
1652 set_page_attributes(mod->module_core + mod->core_text_size,
1653 mod->module_core + mod->core_size,
1654 set_memory_x);
1655 set_page_attributes(mod->module_core,
1656 mod->module_core + mod->core_ro_size,
1657 set_memory_rw);
1658}
1659
1660static void unset_module_init_ro_nx(struct module *mod)
1661{
1662 set_page_attributes(mod->module_init + mod->init_text_size,
1663 mod->module_init + mod->init_size,
1664 set_memory_x);
1665 set_page_attributes(mod->module_init,
1666 mod->module_init + mod->init_ro_size,
1667 set_memory_rw);
1668}
1669
1670/* Iterate through all modules and set each module's text as RW */
1671void set_all_modules_text_rw(void)
1672{
1673 struct module *mod;
1674
1675 mutex_lock(&module_mutex);
1676 list_for_each_entry_rcu(mod, &modules, list) {
1677 if ((mod->module_core) && (mod->core_text_size)) {
1678 set_page_attributes(mod->module_core,
1679 mod->module_core + mod->core_text_size,
1680 set_memory_rw);
1681 }
1682 if ((mod->module_init) && (mod->init_text_size)) {
1683 set_page_attributes(mod->module_init,
1684 mod->module_init + mod->init_text_size,
1685 set_memory_rw);
1686 }
1687 }
1688 mutex_unlock(&module_mutex);
1689}
1690
1691/* Iterate through all modules and set each module's text as RO */
1692void set_all_modules_text_ro(void)
1693{
1694 struct module *mod;
1695
1696 mutex_lock(&module_mutex);
1697 list_for_each_entry_rcu(mod, &modules, list) {
1698 if ((mod->module_core) && (mod->core_text_size)) {
1699 set_page_attributes(mod->module_core,
1700 mod->module_core + mod->core_text_size,
1701 set_memory_ro);
1702 }
1703 if ((mod->module_init) && (mod->init_text_size)) {
1704 set_page_attributes(mod->module_init,
1705 mod->module_init + mod->init_text_size,
1706 set_memory_ro);
1707 }
1708 }
1709 mutex_unlock(&module_mutex);
1710}
1711#else
1712static inline void set_section_ro_nx(void *base, unsigned long text_size, unsigned long ro_size, unsigned long total_size) { }
1713static void unset_module_core_ro_nx(struct module *mod) { }
1714static void unset_module_init_ro_nx(struct module *mod) { }
1715#endif
1716
1717void __weak module_free(struct module *mod, void *module_region)
1718{
1719 vfree(module_region);
1720}
1721
1722void __weak module_arch_cleanup(struct module *mod)
1723{
1724}
1725
1726/* Free a module, remove from lists, etc. */
1727static void free_module(struct module *mod)
1728{
1729 trace_module_free(mod);
1730
1731 /* Delete from various lists */
1732 mutex_lock(&module_mutex);
1733 stop_machine(__unlink_module, mod, NULL);
1734 mutex_unlock(&module_mutex);
1735 mod_sysfs_teardown(mod);
1736
1737 /* Remove dynamic debug info */
1738 ddebug_remove_module(mod->name);
1739
1740 /* Arch-specific cleanup. */
1741 module_arch_cleanup(mod);
1742
1743 /* Module unload stuff */
1744 module_unload_free(mod);
1745
1746 /* Free any allocated parameters. */
1747 destroy_params(mod->kp, mod->num_kp);
1748
1749 /* This may be NULL, but that's OK */
1750 unset_module_init_ro_nx(mod);
1751 module_free(mod, mod->module_init);
1752 kfree(mod->args);
1753 percpu_modfree(mod);
1754
1755 /* Free lock-classes: */
1756 lockdep_free_key_range(mod->module_core, mod->core_size);
1757
1758 /* Finally, free the core (containing the module structure) */
1759 unset_module_core_ro_nx(mod);
1760 module_free(mod, mod->module_core);
1761
1762#ifdef CONFIG_MPU
1763 update_protections(current->mm);
1764#endif
1765}
1766
1767void *__symbol_get(const char *symbol)
1768{
1769 struct module *owner;
1770 const struct kernel_symbol *sym;
1771
1772 preempt_disable();
1773 sym = find_symbol(symbol, &owner, NULL, true, true);
1774 if (sym && strong_try_module_get(owner))
1775 sym = NULL;
1776 preempt_enable();
1777
1778 return sym ? (void *)sym->value : NULL;
1779}
1780EXPORT_SYMBOL_GPL(__symbol_get);
1781
1782/*
1783 * Ensure that an exported symbol [global namespace] does not already exist
1784 * in the kernel or in some other module's exported symbol table.
1785 *
1786 * You must hold the module_mutex.
1787 */
1788static int verify_export_symbols(struct module *mod)
1789{
1790 unsigned int i;
1791 struct module *owner;
1792 const struct kernel_symbol *s;
1793 struct {
1794 const struct kernel_symbol *sym;
1795 unsigned int num;
1796 } arr[] = {
1797 { mod->syms, mod->num_syms },
1798 { mod->gpl_syms, mod->num_gpl_syms },
1799 { mod->gpl_future_syms, mod->num_gpl_future_syms },
1800#ifdef CONFIG_UNUSED_SYMBOLS
1801 { mod->unused_syms, mod->num_unused_syms },
1802 { mod->unused_gpl_syms, mod->num_unused_gpl_syms },
1803#endif
1804 };
1805
1806 for (i = 0; i < ARRAY_SIZE(arr); i++) {
1807 for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
1808 if (find_symbol(s->name, &owner, NULL, true, false)) {
1809 printk(KERN_ERR
1810 "%s: exports duplicate symbol %s"
1811 " (owned by %s)\n",
1812 mod->name, s->name, module_name(owner));
1813 return -ENOEXEC;
1814 }
1815 }
1816 }
1817 return 0;
1818}
1819
1820/* Change all symbols so that st_value encodes the pointer directly. */
1821static int simplify_symbols(struct module *mod, const struct load_info *info)
1822{
1823 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
1824 Elf_Sym *sym = (void *)symsec->sh_addr;
1825 unsigned long secbase;
1826 unsigned int i;
1827 int ret = 0;
1828 const struct kernel_symbol *ksym;
1829
1830 for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
1831 const char *name = info->strtab + sym[i].st_name;
1832
1833 switch (sym[i].st_shndx) {
1834 case SHN_COMMON:
1835 /* We compiled with -fno-common. These are not
1836 supposed to happen. */
1837 DEBUGP("Common symbol: %s\n", name);
1838 printk("%s: please compile with -fno-common\n",
1839 mod->name);
1840 ret = -ENOEXEC;
1841 break;
1842
1843 case SHN_ABS:
1844 /* Don't need to do anything */
1845 DEBUGP("Absolute symbol: 0x%08lx\n",
1846 (long)sym[i].st_value);
1847 break;
1848
1849 case SHN_UNDEF:
1850 ksym = resolve_symbol_wait(mod, info, name);
1851 /* Ok if resolved. */
1852 if (ksym && !IS_ERR(ksym)) {
1853 sym[i].st_value = ksym->value;
1854 break;
1855 }
1856
1857 /* Ok if weak. */
1858 if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
1859 break;
1860
1861 printk(KERN_WARNING "%s: Unknown symbol %s (err %li)\n",
1862 mod->name, name, PTR_ERR(ksym));
1863 ret = PTR_ERR(ksym) ?: -ENOENT;
1864 break;
1865
1866 default:
1867 /* Divert to percpu allocation if a percpu var. */
1868 if (sym[i].st_shndx == info->index.pcpu)
1869 secbase = (unsigned long)mod_percpu(mod);
1870 else
1871 secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
1872 sym[i].st_value += secbase;
1873 break;
1874 }
1875 }
1876
1877 return ret;
1878}
1879
1880int __weak apply_relocate(Elf_Shdr *sechdrs,
1881 const char *strtab,
1882 unsigned int symindex,
1883 unsigned int relsec,
1884 struct module *me)
1885{
1886 pr_err("module %s: REL relocation unsupported\n", me->name);
1887 return -ENOEXEC;
1888}
1889
1890int __weak apply_relocate_add(Elf_Shdr *sechdrs,
1891 const char *strtab,
1892 unsigned int symindex,
1893 unsigned int relsec,
1894 struct module *me)
1895{
1896 pr_err("module %s: RELA relocation unsupported\n", me->name);
1897 return -ENOEXEC;
1898}
1899
1900static int apply_relocations(struct module *mod, const struct load_info *info)
1901{
1902 unsigned int i;
1903 int err = 0;
1904
1905 /* Now do relocations. */
1906 for (i = 1; i < info->hdr->e_shnum; i++) {
1907 unsigned int infosec = info->sechdrs[i].sh_info;
1908
1909 /* Not a valid relocation section? */
1910 if (infosec >= info->hdr->e_shnum)
1911 continue;
1912
1913 /* Don't bother with non-allocated sections */
1914 if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
1915 continue;
1916
1917 if (info->sechdrs[i].sh_type == SHT_REL)
1918 err = apply_relocate(info->sechdrs, info->strtab,
1919 info->index.sym, i, mod);
1920 else if (info->sechdrs[i].sh_type == SHT_RELA)
1921 err = apply_relocate_add(info->sechdrs, info->strtab,
1922 info->index.sym, i, mod);
1923 if (err < 0)
1924 break;
1925 }
1926 return err;
1927}
1928
1929/* Additional bytes needed by arch in front of individual sections */
1930unsigned int __weak arch_mod_section_prepend(struct module *mod,
1931 unsigned int section)
1932{
1933 /* default implementation just returns zero */
1934 return 0;
1935}
1936
1937/* Update size with this section: return offset. */
1938static long get_offset(struct module *mod, unsigned int *size,
1939 Elf_Shdr *sechdr, unsigned int section)
1940{
1941 long ret;
1942
1943 *size += arch_mod_section_prepend(mod, section);
1944 ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
1945 *size = ret + sechdr->sh_size;
1946 return ret;
1947}
1948
1949/* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
1950 might -- code, read-only data, read-write data, small data. Tally
1951 sizes, and place the offsets into sh_entsize fields: high bit means it
1952 belongs in init. */
1953static void layout_sections(struct module *mod, struct load_info *info)
1954{
1955 static unsigned long const masks[][2] = {
1956 /* NOTE: all executable code must be the first section
1957 * in this array; otherwise modify the text_size
1958 * finder in the two loops below */
1959 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
1960 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
1961 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
1962 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
1963 };
1964 unsigned int m, i;
1965
1966 for (i = 0; i < info->hdr->e_shnum; i++)
1967 info->sechdrs[i].sh_entsize = ~0UL;
1968
1969 DEBUGP("Core section allocation order:\n");
1970 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
1971 for (i = 0; i < info->hdr->e_shnum; ++i) {
1972 Elf_Shdr *s = &info->sechdrs[i];
1973 const char *sname = info->secstrings + s->sh_name;
1974
1975 if ((s->sh_flags & masks[m][0]) != masks[m][0]
1976 || (s->sh_flags & masks[m][1])
1977 || s->sh_entsize != ~0UL
1978 || strstarts(sname, ".init"))
1979 continue;
1980 s->sh_entsize = get_offset(mod, &mod->core_size, s, i);
1981 DEBUGP("\t%s\n", name);
1982 }
1983 switch (m) {
1984 case 0: /* executable */
1985 mod->core_size = debug_align(mod->core_size);
1986 mod->core_text_size = mod->core_size;
1987 break;
1988 case 1: /* RO: text and ro-data */
1989 mod->core_size = debug_align(mod->core_size);
1990 mod->core_ro_size = mod->core_size;
1991 break;
1992 case 3: /* whole core */
1993 mod->core_size = debug_align(mod->core_size);
1994 break;
1995 }
1996 }
1997
1998 DEBUGP("Init section allocation order:\n");
1999 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2000 for (i = 0; i < info->hdr->e_shnum; ++i) {
2001 Elf_Shdr *s = &info->sechdrs[i];
2002 const char *sname = info->secstrings + s->sh_name;
2003
2004 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2005 || (s->sh_flags & masks[m][1])
2006 || s->sh_entsize != ~0UL
2007 || !strstarts(sname, ".init"))
2008 continue;
2009 s->sh_entsize = (get_offset(mod, &mod->init_size, s, i)
2010 | INIT_OFFSET_MASK);
2011 DEBUGP("\t%s\n", sname);
2012 }
2013 switch (m) {
2014 case 0: /* executable */
2015 mod->init_size = debug_align(mod->init_size);
2016 mod->init_text_size = mod->init_size;
2017 break;
2018 case 1: /* RO: text and ro-data */
2019 mod->init_size = debug_align(mod->init_size);
2020 mod->init_ro_size = mod->init_size;
2021 break;
2022 case 3: /* whole init */
2023 mod->init_size = debug_align(mod->init_size);
2024 break;
2025 }
2026 }
2027}
2028
2029static void set_license(struct module *mod, const char *license)
2030{
2031 if (!license)
2032 license = "unspecified";
2033
2034 if (!license_is_gpl_compatible(license)) {
2035 if (!test_taint(TAINT_PROPRIETARY_MODULE))
2036 printk(KERN_WARNING "%s: module license '%s' taints "
2037 "kernel.\n", mod->name, license);
2038 add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
2039 }
2040}
2041
2042/* Parse tag=value strings from .modinfo section */
2043static char *next_string(char *string, unsigned long *secsize)
2044{
2045 /* Skip non-zero chars */
2046 while (string[0]) {
2047 string++;
2048 if ((*secsize)-- <= 1)
2049 return NULL;
2050 }
2051
2052 /* Skip any zero padding. */
2053 while (!string[0]) {
2054 string++;
2055 if ((*secsize)-- <= 1)
2056 return NULL;
2057 }
2058 return string;
2059}
2060
2061static char *get_modinfo(struct load_info *info, const char *tag)
2062{
2063 char *p;
2064 unsigned int taglen = strlen(tag);
2065 Elf_Shdr *infosec = &info->sechdrs[info->index.info];
2066 unsigned long size = infosec->sh_size;
2067
2068 for (p = (char *)infosec->sh_addr; p; p = next_string(p, &size)) {
2069 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
2070 return p + taglen + 1;
2071 }
2072 return NULL;
2073}
2074
2075static void setup_modinfo(struct module *mod, struct load_info *info)
2076{
2077 struct module_attribute *attr;
2078 int i;
2079
2080 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2081 if (attr->setup)
2082 attr->setup(mod, get_modinfo(info, attr->attr.name));
2083 }
2084}
2085
2086static void free_modinfo(struct module *mod)
2087{
2088 struct module_attribute *attr;
2089 int i;
2090
2091 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2092 if (attr->free)
2093 attr->free(mod);
2094 }
2095}
2096
2097#ifdef CONFIG_KALLSYMS
2098
2099/* lookup symbol in given range of kernel_symbols */
2100static const struct kernel_symbol *lookup_symbol(const char *name,
2101 const struct kernel_symbol *start,
2102 const struct kernel_symbol *stop)
2103{
2104 return bsearch(name, start, stop - start,
2105 sizeof(struct kernel_symbol), cmp_name);
2106}
2107
2108static int is_exported(const char *name, unsigned long value,
2109 const struct module *mod)
2110{
2111 const struct kernel_symbol *ks;
2112 if (!mod)
2113 ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
2114 else
2115 ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
2116 return ks != NULL && ks->value == value;
2117}
2118
2119/* As per nm */
2120static char elf_type(const Elf_Sym *sym, const struct load_info *info)
2121{
2122 const Elf_Shdr *sechdrs = info->sechdrs;
2123
2124 if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
2125 if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
2126 return 'v';
2127 else
2128 return 'w';
2129 }
2130 if (sym->st_shndx == SHN_UNDEF)
2131 return 'U';
2132 if (sym->st_shndx == SHN_ABS)
2133 return 'a';
2134 if (sym->st_shndx >= SHN_LORESERVE)
2135 return '?';
2136 if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
2137 return 't';
2138 if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
2139 && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
2140 if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
2141 return 'r';
2142 else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2143 return 'g';
2144 else
2145 return 'd';
2146 }
2147 if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
2148 if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2149 return 's';
2150 else
2151 return 'b';
2152 }
2153 if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
2154 ".debug")) {
2155 return 'n';
2156 }
2157 return '?';
2158}
2159
2160static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
2161 unsigned int shnum)
2162{
2163 const Elf_Shdr *sec;
2164
2165 if (src->st_shndx == SHN_UNDEF
2166 || src->st_shndx >= shnum
2167 || !src->st_name)
2168 return false;
2169
2170 sec = sechdrs + src->st_shndx;
2171 if (!(sec->sh_flags & SHF_ALLOC)
2172#ifndef CONFIG_KALLSYMS_ALL
2173 || !(sec->sh_flags & SHF_EXECINSTR)
2174#endif
2175 || (sec->sh_entsize & INIT_OFFSET_MASK))
2176 return false;
2177
2178 return true;
2179}
2180
2181static void layout_symtab(struct module *mod, struct load_info *info)
2182{
2183 Elf_Shdr *symsect = info->sechdrs + info->index.sym;
2184 Elf_Shdr *strsect = info->sechdrs + info->index.str;
2185 const Elf_Sym *src;
2186 unsigned int i, nsrc, ndst;
2187
2188 /* Put symbol section at end of init part of module. */
2189 symsect->sh_flags |= SHF_ALLOC;
2190 symsect->sh_entsize = get_offset(mod, &mod->init_size, symsect,
2191 info->index.sym) | INIT_OFFSET_MASK;
2192 DEBUGP("\t%s\n", info->secstrings + symsect->sh_name);
2193
2194 src = (void *)info->hdr + symsect->sh_offset;
2195 nsrc = symsect->sh_size / sizeof(*src);
2196 for (ndst = i = 1; i < nsrc; ++i, ++src)
2197 if (is_core_symbol(src, info->sechdrs, info->hdr->e_shnum)) {
2198 unsigned int j = src->st_name;
2199
2200 while (!__test_and_set_bit(j, info->strmap)
2201 && info->strtab[j])
2202 ++j;
2203 ++ndst;
2204 }
2205
2206 /* Append room for core symbols at end of core part. */
2207 info->symoffs = ALIGN(mod->core_size, symsect->sh_addralign ?: 1);
2208 mod->core_size = info->symoffs + ndst * sizeof(Elf_Sym);
2209
2210 /* Put string table section at end of init part of module. */
2211 strsect->sh_flags |= SHF_ALLOC;
2212 strsect->sh_entsize = get_offset(mod, &mod->init_size, strsect,
2213 info->index.str) | INIT_OFFSET_MASK;
2214 DEBUGP("\t%s\n", info->secstrings + strsect->sh_name);
2215
2216 /* Append room for core symbols' strings at end of core part. */
2217 info->stroffs = mod->core_size;
2218 __set_bit(0, info->strmap);
2219 mod->core_size += bitmap_weight(info->strmap, strsect->sh_size);
2220}
2221
2222static void add_kallsyms(struct module *mod, const struct load_info *info)
2223{
2224 unsigned int i, ndst;
2225 const Elf_Sym *src;
2226 Elf_Sym *dst;
2227 char *s;
2228 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2229
2230 mod->symtab = (void *)symsec->sh_addr;
2231 mod->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
2232 /* Make sure we get permanent strtab: don't use info->strtab. */
2233 mod->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
2234
2235 /* Set types up while we still have access to sections. */
2236 for (i = 0; i < mod->num_symtab; i++)
2237 mod->symtab[i].st_info = elf_type(&mod->symtab[i], info);
2238
2239 mod->core_symtab = dst = mod->module_core + info->symoffs;
2240 src = mod->symtab;
2241 *dst = *src;
2242 for (ndst = i = 1; i < mod->num_symtab; ++i, ++src) {
2243 if (!is_core_symbol(src, info->sechdrs, info->hdr->e_shnum))
2244 continue;
2245 dst[ndst] = *src;
2246 dst[ndst].st_name = bitmap_weight(info->strmap,
2247 dst[ndst].st_name);
2248 ++ndst;
2249 }
2250 mod->core_num_syms = ndst;
2251
2252 mod->core_strtab = s = mod->module_core + info->stroffs;
2253 for (*s = 0, i = 1; i < info->sechdrs[info->index.str].sh_size; ++i)
2254 if (test_bit(i, info->strmap))
2255 *++s = mod->strtab[i];
2256}
2257#else
2258static inline void layout_symtab(struct module *mod, struct load_info *info)
2259{
2260}
2261
2262static void add_kallsyms(struct module *mod, const struct load_info *info)
2263{
2264}
2265#endif /* CONFIG_KALLSYMS */
2266
2267static void dynamic_debug_setup(struct _ddebug *debug, unsigned int num)
2268{
2269 if (!debug)
2270 return;
2271#ifdef CONFIG_DYNAMIC_DEBUG
2272 if (ddebug_add_module(debug, num, debug->modname))
2273 printk(KERN_ERR "dynamic debug error adding module: %s\n",
2274 debug->modname);
2275#endif
2276}
2277
2278static void dynamic_debug_remove(struct _ddebug *debug)
2279{
2280 if (debug)
2281 ddebug_remove_module(debug->modname);
2282}
2283
2284void * __weak module_alloc(unsigned long size)
2285{
2286 return size == 0 ? NULL : vmalloc_exec(size);
2287}
2288
2289static void *module_alloc_update_bounds(unsigned long size)
2290{
2291 void *ret = module_alloc(size);
2292
2293 if (ret) {
2294 mutex_lock(&module_mutex);
2295 /* Update module bounds. */
2296 if ((unsigned long)ret < module_addr_min)
2297 module_addr_min = (unsigned long)ret;
2298 if ((unsigned long)ret + size > module_addr_max)
2299 module_addr_max = (unsigned long)ret + size;
2300 mutex_unlock(&module_mutex);
2301 }
2302 return ret;
2303}
2304
2305#ifdef CONFIG_DEBUG_KMEMLEAK
2306static void kmemleak_load_module(const struct module *mod,
2307 const struct load_info *info)
2308{
2309 unsigned int i;
2310
2311 /* only scan the sections containing data */
2312 kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
2313
2314 for (i = 1; i < info->hdr->e_shnum; i++) {
2315 const char *name = info->secstrings + info->sechdrs[i].sh_name;
2316 if (!(info->sechdrs[i].sh_flags & SHF_ALLOC))
2317 continue;
2318 if (!strstarts(name, ".data") && !strstarts(name, ".bss"))
2319 continue;
2320
2321 kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
2322 info->sechdrs[i].sh_size, GFP_KERNEL);
2323 }
2324}
2325#else
2326static inline void kmemleak_load_module(const struct module *mod,
2327 const struct load_info *info)
2328{
2329}
2330#endif
2331
2332/* Sets info->hdr and info->len. */
2333static int copy_and_check(struct load_info *info,
2334 const void __user *umod, unsigned long len,
2335 const char __user *uargs)
2336{
2337 int err;
2338 Elf_Ehdr *hdr;
2339
2340 if (len < sizeof(*hdr))
2341 return -ENOEXEC;
2342
2343 /* Suck in entire file: we'll want most of it. */
2344 /* vmalloc barfs on "unusual" numbers. Check here */
2345 if (len > 64 * 1024 * 1024 || (hdr = vmalloc(len)) == NULL)
2346 return -ENOMEM;
2347
2348 if (copy_from_user(hdr, umod, len) != 0) {
2349 err = -EFAULT;
2350 goto free_hdr;
2351 }
2352
2353 /* Sanity checks against insmoding binaries or wrong arch,
2354 weird elf version */
2355 if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0
2356 || hdr->e_type != ET_REL
2357 || !elf_check_arch(hdr)
2358 || hdr->e_shentsize != sizeof(Elf_Shdr)) {
2359 err = -ENOEXEC;
2360 goto free_hdr;
2361 }
2362
2363 if (len < hdr->e_shoff + hdr->e_shnum * sizeof(Elf_Shdr)) {
2364 err = -ENOEXEC;
2365 goto free_hdr;
2366 }
2367
2368 info->hdr = hdr;
2369 info->len = len;
2370 return 0;
2371
2372free_hdr:
2373 vfree(hdr);
2374 return err;
2375}
2376
2377static void free_copy(struct load_info *info)
2378{
2379 vfree(info->hdr);
2380}
2381
2382static int rewrite_section_headers(struct load_info *info)
2383{
2384 unsigned int i;
2385
2386 /* This should always be true, but let's be sure. */
2387 info->sechdrs[0].sh_addr = 0;
2388
2389 for (i = 1; i < info->hdr->e_shnum; i++) {
2390 Elf_Shdr *shdr = &info->sechdrs[i];
2391 if (shdr->sh_type != SHT_NOBITS
2392 && info->len < shdr->sh_offset + shdr->sh_size) {
2393 printk(KERN_ERR "Module len %lu truncated\n",
2394 info->len);
2395 return -ENOEXEC;
2396 }
2397
2398 /* Mark all sections sh_addr with their address in the
2399 temporary image. */
2400 shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
2401
2402#ifndef CONFIG_MODULE_UNLOAD
2403 /* Don't load .exit sections */
2404 if (strstarts(info->secstrings+shdr->sh_name, ".exit"))
2405 shdr->sh_flags &= ~(unsigned long)SHF_ALLOC;
2406#endif
2407 }
2408
2409 /* Track but don't keep modinfo and version sections. */
2410 info->index.vers = find_sec(info, "__versions");
2411 info->index.info = find_sec(info, ".modinfo");
2412 info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
2413 info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
2414 return 0;
2415}
2416
2417/*
2418 * Set up our basic convenience variables (pointers to section headers,
2419 * search for module section index etc), and do some basic section
2420 * verification.
2421 *
2422 * Return the temporary module pointer (we'll replace it with the final
2423 * one when we move the module sections around).
2424 */
2425static struct module *setup_load_info(struct load_info *info)
2426{
2427 unsigned int i;
2428 int err;
2429 struct module *mod;
2430
2431 /* Set up the convenience variables */
2432 info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
2433 info->secstrings = (void *)info->hdr
2434 + info->sechdrs[info->hdr->e_shstrndx].sh_offset;
2435
2436 err = rewrite_section_headers(info);
2437 if (err)
2438 return ERR_PTR(err);
2439
2440 /* Find internal symbols and strings. */
2441 for (i = 1; i < info->hdr->e_shnum; i++) {
2442 if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
2443 info->index.sym = i;
2444 info->index.str = info->sechdrs[i].sh_link;
2445 info->strtab = (char *)info->hdr
2446 + info->sechdrs[info->index.str].sh_offset;
2447 break;
2448 }
2449 }
2450
2451 info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
2452 if (!info->index.mod) {
2453 printk(KERN_WARNING "No module found in object\n");
2454 return ERR_PTR(-ENOEXEC);
2455 }
2456 /* This is temporary: point mod into copy of data. */
2457 mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2458
2459 if (info->index.sym == 0) {
2460 printk(KERN_WARNING "%s: module has no symbols (stripped?)\n",
2461 mod->name);
2462 return ERR_PTR(-ENOEXEC);
2463 }
2464
2465 info->index.pcpu = find_pcpusec(info);
2466
2467 /* Check module struct version now, before we try to use module. */
2468 if (!check_modstruct_version(info->sechdrs, info->index.vers, mod))
2469 return ERR_PTR(-ENOEXEC);
2470
2471 return mod;
2472}
2473
2474static int check_modinfo(struct module *mod, struct load_info *info)
2475{
2476 const char *modmagic = get_modinfo(info, "vermagic");
2477 int err;
2478
2479 /* This is allowed: modprobe --force will invalidate it. */
2480 if (!modmagic) {
2481 err = try_to_force_load(mod, "bad vermagic");
2482 if (err)
2483 return err;
2484 } else if (!same_magic(modmagic, vermagic, info->index.vers)) {
2485 printk(KERN_ERR "%s: version magic '%s' should be '%s'\n",
2486 mod->name, modmagic, vermagic);
2487 return -ENOEXEC;
2488 }
2489
2490 if (!get_modinfo(info, "intree"))
2491 add_taint_module(mod, TAINT_OOT_MODULE);
2492
2493 if (get_modinfo(info, "staging")) {
2494 add_taint_module(mod, TAINT_CRAP);
2495 printk(KERN_WARNING "%s: module is from the staging directory,"
2496 " the quality is unknown, you have been warned.\n",
2497 mod->name);
2498 }
2499
2500 /* Set up license info based on the info section */
2501 set_license(mod, get_modinfo(info, "license"));
2502
2503 return 0;
2504}
2505
2506static void find_module_sections(struct module *mod, struct load_info *info)
2507{
2508 mod->kp = section_objs(info, "__param",
2509 sizeof(*mod->kp), &mod->num_kp);
2510 mod->syms = section_objs(info, "__ksymtab",
2511 sizeof(*mod->syms), &mod->num_syms);
2512 mod->crcs = section_addr(info, "__kcrctab");
2513 mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
2514 sizeof(*mod->gpl_syms),
2515 &mod->num_gpl_syms);
2516 mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
2517 mod->gpl_future_syms = section_objs(info,
2518 "__ksymtab_gpl_future",
2519 sizeof(*mod->gpl_future_syms),
2520 &mod->num_gpl_future_syms);
2521 mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future");
2522
2523#ifdef CONFIG_UNUSED_SYMBOLS
2524 mod->unused_syms = section_objs(info, "__ksymtab_unused",
2525 sizeof(*mod->unused_syms),
2526 &mod->num_unused_syms);
2527 mod->unused_crcs = section_addr(info, "__kcrctab_unused");
2528 mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl",
2529 sizeof(*mod->unused_gpl_syms),
2530 &mod->num_unused_gpl_syms);
2531 mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl");
2532#endif
2533#ifdef CONFIG_CONSTRUCTORS
2534 mod->ctors = section_objs(info, ".ctors",
2535 sizeof(*mod->ctors), &mod->num_ctors);
2536#endif
2537
2538#ifdef CONFIG_TRACEPOINTS
2539 mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
2540 sizeof(*mod->tracepoints_ptrs),
2541 &mod->num_tracepoints);
2542#endif
2543#ifdef HAVE_JUMP_LABEL
2544 mod->jump_entries = section_objs(info, "__jump_table",
2545 sizeof(*mod->jump_entries),
2546 &mod->num_jump_entries);
2547#endif
2548#ifdef CONFIG_EVENT_TRACING
2549 mod->trace_events = section_objs(info, "_ftrace_events",
2550 sizeof(*mod->trace_events),
2551 &mod->num_trace_events);
2552 /*
2553 * This section contains pointers to allocated objects in the trace
2554 * code and not scanning it leads to false positives.
2555 */
2556 kmemleak_scan_area(mod->trace_events, sizeof(*mod->trace_events) *
2557 mod->num_trace_events, GFP_KERNEL);
2558#endif
2559#ifdef CONFIG_TRACING
2560 mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
2561 sizeof(*mod->trace_bprintk_fmt_start),
2562 &mod->num_trace_bprintk_fmt);
2563 /*
2564 * This section contains pointers to allocated objects in the trace
2565 * code and not scanning it leads to false positives.
2566 */
2567 kmemleak_scan_area(mod->trace_bprintk_fmt_start,
2568 sizeof(*mod->trace_bprintk_fmt_start) *
2569 mod->num_trace_bprintk_fmt, GFP_KERNEL);
2570#endif
2571#ifdef CONFIG_FTRACE_MCOUNT_RECORD
2572 /* sechdrs[0].sh_size is always zero */
2573 mod->ftrace_callsites = section_objs(info, "__mcount_loc",
2574 sizeof(*mod->ftrace_callsites),
2575 &mod->num_ftrace_callsites);
2576#endif
2577
2578 mod->extable = section_objs(info, "__ex_table",
2579 sizeof(*mod->extable), &mod->num_exentries);
2580
2581 if (section_addr(info, "__obsparm"))
2582 printk(KERN_WARNING "%s: Ignoring obsolete parameters\n",
2583 mod->name);
2584
2585 info->debug = section_objs(info, "__verbose",
2586 sizeof(*info->debug), &info->num_debug);
2587}
2588
2589static int move_module(struct module *mod, struct load_info *info)
2590{
2591 int i;
2592 void *ptr;
2593
2594 /* Do the allocs. */
2595 ptr = module_alloc_update_bounds(mod->core_size);
2596 /*
2597 * The pointer to this block is stored in the module structure
2598 * which is inside the block. Just mark it as not being a
2599 * leak.
2600 */
2601 kmemleak_not_leak(ptr);
2602 if (!ptr)
2603 return -ENOMEM;
2604
2605 memset(ptr, 0, mod->core_size);
2606 mod->module_core = ptr;
2607
2608 ptr = module_alloc_update_bounds(mod->init_size);
2609 /*
2610 * The pointer to this block is stored in the module structure
2611 * which is inside the block. This block doesn't need to be
2612 * scanned as it contains data and code that will be freed
2613 * after the module is initialized.
2614 */
2615 kmemleak_ignore(ptr);
2616 if (!ptr && mod->init_size) {
2617 module_free(mod, mod->module_core);
2618 return -ENOMEM;
2619 }
2620 memset(ptr, 0, mod->init_size);
2621 mod->module_init = ptr;
2622
2623 /* Transfer each section which specifies SHF_ALLOC */
2624 DEBUGP("final section addresses:\n");
2625 for (i = 0; i < info->hdr->e_shnum; i++) {
2626 void *dest;
2627 Elf_Shdr *shdr = &info->sechdrs[i];
2628
2629 if (!(shdr->sh_flags & SHF_ALLOC))
2630 continue;
2631
2632 if (shdr->sh_entsize & INIT_OFFSET_MASK)
2633 dest = mod->module_init
2634 + (shdr->sh_entsize & ~INIT_OFFSET_MASK);
2635 else
2636 dest = mod->module_core + shdr->sh_entsize;
2637
2638 if (shdr->sh_type != SHT_NOBITS)
2639 memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
2640 /* Update sh_addr to point to copy in image. */
2641 shdr->sh_addr = (unsigned long)dest;
2642 DEBUGP("\t0x%lx %s\n",
2643 shdr->sh_addr, info->secstrings + shdr->sh_name);
2644 }
2645
2646 return 0;
2647}
2648
2649static int check_module_license_and_versions(struct module *mod)
2650{
2651 /*
2652 * ndiswrapper is under GPL by itself, but loads proprietary modules.
2653 * Don't use add_taint_module(), as it would prevent ndiswrapper from
2654 * using GPL-only symbols it needs.
2655 */
2656 if (strcmp(mod->name, "ndiswrapper") == 0)
2657 add_taint(TAINT_PROPRIETARY_MODULE);
2658
2659 /* driverloader was caught wrongly pretending to be under GPL */
2660 if (strcmp(mod->name, "driverloader") == 0)
2661 add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
2662
2663#ifdef CONFIG_MODVERSIONS
2664 if ((mod->num_syms && !mod->crcs)
2665 || (mod->num_gpl_syms && !mod->gpl_crcs)
2666 || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
2667#ifdef CONFIG_UNUSED_SYMBOLS
2668 || (mod->num_unused_syms && !mod->unused_crcs)
2669 || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
2670#endif
2671 ) {
2672 return try_to_force_load(mod,
2673 "no versions for exported symbols");
2674 }
2675#endif
2676 return 0;
2677}
2678
2679static void flush_module_icache(const struct module *mod)
2680{
2681 mm_segment_t old_fs;
2682
2683 /* flush the icache in correct context */
2684 old_fs = get_fs();
2685 set_fs(KERNEL_DS);
2686
2687 /*
2688 * Flush the instruction cache, since we've played with text.
2689 * Do it before processing of module parameters, so the module
2690 * can provide parameter accessor functions of its own.
2691 */
2692 if (mod->module_init)
2693 flush_icache_range((unsigned long)mod->module_init,
2694 (unsigned long)mod->module_init
2695 + mod->init_size);
2696 flush_icache_range((unsigned long)mod->module_core,
2697 (unsigned long)mod->module_core + mod->core_size);
2698
2699 set_fs(old_fs);
2700}
2701
2702int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
2703 Elf_Shdr *sechdrs,
2704 char *secstrings,
2705 struct module *mod)
2706{
2707 return 0;
2708}
2709
2710static struct module *layout_and_allocate(struct load_info *info)
2711{
2712 /* Module within temporary copy. */
2713 struct module *mod;
2714 Elf_Shdr *pcpusec;
2715 int err;
2716
2717 mod = setup_load_info(info);
2718 if (IS_ERR(mod))
2719 return mod;
2720
2721 err = check_modinfo(mod, info);
2722 if (err)
2723 return ERR_PTR(err);
2724
2725 /* Allow arches to frob section contents and sizes. */
2726 err = module_frob_arch_sections(info->hdr, info->sechdrs,
2727 info->secstrings, mod);
2728 if (err < 0)
2729 goto out;
2730
2731 pcpusec = &info->sechdrs[info->index.pcpu];
2732 if (pcpusec->sh_size) {
2733 /* We have a special allocation for this section. */
2734 err = percpu_modalloc(mod,
2735 pcpusec->sh_size, pcpusec->sh_addralign);
2736 if (err)
2737 goto out;
2738 pcpusec->sh_flags &= ~(unsigned long)SHF_ALLOC;
2739 }
2740
2741 /* Determine total sizes, and put offsets in sh_entsize. For now
2742 this is done generically; there doesn't appear to be any
2743 special cases for the architectures. */
2744 layout_sections(mod, info);
2745
2746 info->strmap = kzalloc(BITS_TO_LONGS(info->sechdrs[info->index.str].sh_size)
2747 * sizeof(long), GFP_KERNEL);
2748 if (!info->strmap) {
2749 err = -ENOMEM;
2750 goto free_percpu;
2751 }
2752 layout_symtab(mod, info);
2753
2754 /* Allocate and move to the final place */
2755 err = move_module(mod, info);
2756 if (err)
2757 goto free_strmap;
2758
2759 /* Module has been copied to its final place now: return it. */
2760 mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2761 kmemleak_load_module(mod, info);
2762 return mod;
2763
2764free_strmap:
2765 kfree(info->strmap);
2766free_percpu:
2767 percpu_modfree(mod);
2768out:
2769 return ERR_PTR(err);
2770}
2771
2772/* mod is no longer valid after this! */
2773static void module_deallocate(struct module *mod, struct load_info *info)
2774{
2775 kfree(info->strmap);
2776 percpu_modfree(mod);
2777 module_free(mod, mod->module_init);
2778 module_free(mod, mod->module_core);
2779}
2780
2781int __weak module_finalize(const Elf_Ehdr *hdr,
2782 const Elf_Shdr *sechdrs,
2783 struct module *me)
2784{
2785 return 0;
2786}
2787
2788static int post_relocation(struct module *mod, const struct load_info *info)
2789{
2790 /* Sort exception table now relocations are done. */
2791 sort_extable(mod->extable, mod->extable + mod->num_exentries);
2792
2793 /* Copy relocated percpu area over. */
2794 percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
2795 info->sechdrs[info->index.pcpu].sh_size);
2796
2797 /* Setup kallsyms-specific fields. */
2798 add_kallsyms(mod, info);
2799
2800 /* Arch-specific module finalizing. */
2801 return module_finalize(info->hdr, info->sechdrs, mod);
2802}
2803
2804/* Allocate and load the module: note that size of section 0 is always
2805 zero, and we rely on this for optional sections. */
2806static struct module *load_module(void __user *umod,
2807 unsigned long len,
2808 const char __user *uargs)
2809{
2810 struct load_info info = { NULL, };
2811 struct module *mod;
2812 long err;
2813
2814 DEBUGP("load_module: umod=%p, len=%lu, uargs=%p\n",
2815 umod, len, uargs);
2816
2817 /* Copy in the blobs from userspace, check they are vaguely sane. */
2818 err = copy_and_check(&info, umod, len, uargs);
2819 if (err)
2820 return ERR_PTR(err);
2821
2822 /* Figure out module layout, and allocate all the memory. */
2823 mod = layout_and_allocate(&info);
2824 if (IS_ERR(mod)) {
2825 err = PTR_ERR(mod);
2826 goto free_copy;
2827 }
2828
2829 /* Now module is in final location, initialize linked lists, etc. */
2830 err = module_unload_init(mod);
2831 if (err)
2832 goto free_module;
2833
2834 /* Now we've got everything in the final locations, we can
2835 * find optional sections. */
2836 find_module_sections(mod, &info);
2837
2838 err = check_module_license_and_versions(mod);
2839 if (err)
2840 goto free_unload;
2841
2842 /* Set up MODINFO_ATTR fields */
2843 setup_modinfo(mod, &info);
2844
2845 /* Fix up syms, so that st_value is a pointer to location. */
2846 err = simplify_symbols(mod, &info);
2847 if (err < 0)
2848 goto free_modinfo;
2849
2850 err = apply_relocations(mod, &info);
2851 if (err < 0)
2852 goto free_modinfo;
2853
2854 err = post_relocation(mod, &info);
2855 if (err < 0)
2856 goto free_modinfo;
2857
2858 flush_module_icache(mod);
2859
2860 /* Now copy in args */
2861 mod->args = strndup_user(uargs, ~0UL >> 1);
2862 if (IS_ERR(mod->args)) {
2863 err = PTR_ERR(mod->args);
2864 goto free_arch_cleanup;
2865 }
2866
2867 /* Mark state as coming so strong_try_module_get() ignores us. */
2868 mod->state = MODULE_STATE_COMING;
2869
2870 /* Now sew it into the lists so we can get lockdep and oops
2871 * info during argument parsing. No one should access us, since
2872 * strong_try_module_get() will fail.
2873 * lockdep/oops can run asynchronous, so use the RCU list insertion
2874 * function to insert in a way safe to concurrent readers.
2875 * The mutex protects against concurrent writers.
2876 */
2877 mutex_lock(&module_mutex);
2878 if (find_module(mod->name)) {
2879 err = -EEXIST;
2880 goto unlock;
2881 }
2882
2883 /* This has to be done once we're sure module name is unique. */
2884 dynamic_debug_setup(info.debug, info.num_debug);
2885
2886 /* Find duplicate symbols */
2887 err = verify_export_symbols(mod);
2888 if (err < 0)
2889 goto ddebug;
2890
2891 module_bug_finalize(info.hdr, info.sechdrs, mod);
2892 list_add_rcu(&mod->list, &modules);
2893 mutex_unlock(&module_mutex);
2894
2895 /* Module is ready to execute: parsing args may do that. */
2896 err = parse_args(mod->name, mod->args, mod->kp, mod->num_kp, NULL);
2897 if (err < 0)
2898 goto unlink;
2899
2900 /* Link in to syfs. */
2901 err = mod_sysfs_setup(mod, &info, mod->kp, mod->num_kp);
2902 if (err < 0)
2903 goto unlink;
2904
2905 /* Get rid of temporary copy and strmap. */
2906 kfree(info.strmap);
2907 free_copy(&info);
2908
2909 /* Done! */
2910 trace_module_load(mod);
2911 return mod;
2912
2913 unlink:
2914 mutex_lock(&module_mutex);
2915 /* Unlink carefully: kallsyms could be walking list. */
2916 list_del_rcu(&mod->list);
2917 module_bug_cleanup(mod);
2918
2919 ddebug:
2920 dynamic_debug_remove(info.debug);
2921 unlock:
2922 mutex_unlock(&module_mutex);
2923 synchronize_sched();
2924 kfree(mod->args);
2925 free_arch_cleanup:
2926 module_arch_cleanup(mod);
2927 free_modinfo:
2928 free_modinfo(mod);
2929 free_unload:
2930 module_unload_free(mod);
2931 free_module:
2932 module_deallocate(mod, &info);
2933 free_copy:
2934 free_copy(&info);
2935 return ERR_PTR(err);
2936}
2937
2938/* Call module constructors. */
2939static void do_mod_ctors(struct module *mod)
2940{
2941#ifdef CONFIG_CONSTRUCTORS
2942 unsigned long i;
2943
2944 for (i = 0; i < mod->num_ctors; i++)
2945 mod->ctors[i]();
2946#endif
2947}
2948
2949/* This is where the real work happens */
2950SYSCALL_DEFINE3(init_module, void __user *, umod,
2951 unsigned long, len, const char __user *, uargs)
2952{
2953 struct module *mod;
2954 int ret = 0;
2955
2956 /* Must have permission */
2957 if (!capable(CAP_SYS_MODULE) || modules_disabled)
2958 return -EPERM;
2959
2960 /* Do all the hard work */
2961 mod = load_module(umod, len, uargs);
2962 if (IS_ERR(mod))
2963 return PTR_ERR(mod);
2964
2965 blocking_notifier_call_chain(&module_notify_list,
2966 MODULE_STATE_COMING, mod);
2967
2968 /* Set RO and NX regions for core */
2969 set_section_ro_nx(mod->module_core,
2970 mod->core_text_size,
2971 mod->core_ro_size,
2972 mod->core_size);
2973
2974 /* Set RO and NX regions for init */
2975 set_section_ro_nx(mod->module_init,
2976 mod->init_text_size,
2977 mod->init_ro_size,
2978 mod->init_size);
2979
2980 do_mod_ctors(mod);
2981 /* Start the module */
2982 if (mod->init != NULL)
2983 ret = do_one_initcall(mod->init);
2984 if (ret < 0) {
2985 /* Init routine failed: abort. Try to protect us from
2986 buggy refcounters. */
2987 mod->state = MODULE_STATE_GOING;
2988 synchronize_sched();
2989 module_put(mod);
2990 blocking_notifier_call_chain(&module_notify_list,
2991 MODULE_STATE_GOING, mod);
2992 free_module(mod);
2993 wake_up(&module_wq);
2994 return ret;
2995 }
2996 if (ret > 0) {
2997 printk(KERN_WARNING
2998"%s: '%s'->init suspiciously returned %d, it should follow 0/-E convention\n"
2999"%s: loading module anyway...\n",
3000 __func__, mod->name, ret,
3001 __func__);
3002 dump_stack();
3003 }
3004
3005 /* Now it's a first class citizen! Wake up anyone waiting for it. */
3006 mod->state = MODULE_STATE_LIVE;
3007 wake_up(&module_wq);
3008 blocking_notifier_call_chain(&module_notify_list,
3009 MODULE_STATE_LIVE, mod);
3010
3011 /* We need to finish all async code before the module init sequence is done */
3012 async_synchronize_full();
3013
3014 mutex_lock(&module_mutex);
3015 /* Drop initial reference. */
3016 module_put(mod);
3017 trim_init_extable(mod);
3018#ifdef CONFIG_KALLSYMS
3019 mod->num_symtab = mod->core_num_syms;
3020 mod->symtab = mod->core_symtab;
3021 mod->strtab = mod->core_strtab;
3022#endif
3023 unset_module_init_ro_nx(mod);
3024 module_free(mod, mod->module_init);
3025 mod->module_init = NULL;
3026 mod->init_size = 0;
3027 mod->init_ro_size = 0;
3028 mod->init_text_size = 0;
3029 mutex_unlock(&module_mutex);
3030
3031 return 0;
3032}
3033
3034static inline int within(unsigned long addr, void *start, unsigned long size)
3035{
3036 return ((void *)addr >= start && (void *)addr < start + size);
3037}
3038
3039#ifdef CONFIG_KALLSYMS
3040/*
3041 * This ignores the intensely annoying "mapping symbols" found
3042 * in ARM ELF files: $a, $t and $d.
3043 */
3044static inline int is_arm_mapping_symbol(const char *str)
3045{
3046 return str[0] == '$' && strchr("atd", str[1])
3047 && (str[2] == '\0' || str[2] == '.');
3048}
3049
3050static const char *get_ksymbol(struct module *mod,
3051 unsigned long addr,
3052 unsigned long *size,
3053 unsigned long *offset)
3054{
3055 unsigned int i, best = 0;
3056 unsigned long nextval;
3057
3058 /* At worse, next value is at end of module */
3059 if (within_module_init(addr, mod))
3060 nextval = (unsigned long)mod->module_init+mod->init_text_size;
3061 else
3062 nextval = (unsigned long)mod->module_core+mod->core_text_size;
3063
3064 /* Scan for closest preceding symbol, and next symbol. (ELF
3065 starts real symbols at 1). */
3066 for (i = 1; i < mod->num_symtab; i++) {
3067 if (mod->symtab[i].st_shndx == SHN_UNDEF)
3068 continue;
3069
3070 /* We ignore unnamed symbols: they're uninformative
3071 * and inserted at a whim. */
3072 if (mod->symtab[i].st_value <= addr
3073 && mod->symtab[i].st_value > mod->symtab[best].st_value
3074 && *(mod->strtab + mod->symtab[i].st_name) != '\0'
3075 && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
3076 best = i;
3077 if (mod->symtab[i].st_value > addr
3078 && mod->symtab[i].st_value < nextval
3079 && *(mod->strtab + mod->symtab[i].st_name) != '\0'
3080 && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
3081 nextval = mod->symtab[i].st_value;
3082 }
3083
3084 if (!best)
3085 return NULL;
3086
3087 if (size)
3088 *size = nextval - mod->symtab[best].st_value;
3089 if (offset)
3090 *offset = addr - mod->symtab[best].st_value;
3091 return mod->strtab + mod->symtab[best].st_name;
3092}
3093
3094/* For kallsyms to ask for address resolution. NULL means not found. Careful
3095 * not to lock to avoid deadlock on oopses, simply disable preemption. */
3096const char *module_address_lookup(unsigned long addr,
3097 unsigned long *size,
3098 unsigned long *offset,
3099 char **modname,
3100 char *namebuf)
3101{
3102 struct module *mod;
3103 const char *ret = NULL;
3104
3105 preempt_disable();
3106 list_for_each_entry_rcu(mod, &modules, list) {
3107 if (within_module_init(addr, mod) ||
3108 within_module_core(addr, mod)) {
3109 if (modname)
3110 *modname = mod->name;
3111 ret = get_ksymbol(mod, addr, size, offset);
3112 break;
3113 }
3114 }
3115 /* Make a copy in here where it's safe */
3116 if (ret) {
3117 strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
3118 ret = namebuf;
3119 }
3120 preempt_enable();
3121 return ret;
3122}
3123
3124int lookup_module_symbol_name(unsigned long addr, char *symname)
3125{
3126 struct module *mod;
3127
3128 preempt_disable();
3129 list_for_each_entry_rcu(mod, &modules, list) {
3130 if (within_module_init(addr, mod) ||
3131 within_module_core(addr, mod)) {
3132 const char *sym;
3133
3134 sym = get_ksymbol(mod, addr, NULL, NULL);
3135 if (!sym)
3136 goto out;
3137 strlcpy(symname, sym, KSYM_NAME_LEN);
3138 preempt_enable();
3139 return 0;
3140 }
3141 }
3142out:
3143 preempt_enable();
3144 return -ERANGE;
3145}
3146
3147int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
3148 unsigned long *offset, char *modname, char *name)
3149{
3150 struct module *mod;
3151
3152 preempt_disable();
3153 list_for_each_entry_rcu(mod, &modules, list) {
3154 if (within_module_init(addr, mod) ||
3155 within_module_core(addr, mod)) {
3156 const char *sym;
3157
3158 sym = get_ksymbol(mod, addr, size, offset);
3159 if (!sym)
3160 goto out;
3161 if (modname)
3162 strlcpy(modname, mod->name, MODULE_NAME_LEN);
3163 if (name)
3164 strlcpy(name, sym, KSYM_NAME_LEN);
3165 preempt_enable();
3166 return 0;
3167 }
3168 }
3169out:
3170 preempt_enable();
3171 return -ERANGE;
3172}
3173
3174int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
3175 char *name, char *module_name, int *exported)
3176{
3177 struct module *mod;
3178
3179 preempt_disable();
3180 list_for_each_entry_rcu(mod, &modules, list) {
3181 if (symnum < mod->num_symtab) {
3182 *value = mod->symtab[symnum].st_value;
3183 *type = mod->symtab[symnum].st_info;
3184 strlcpy(name, mod->strtab + mod->symtab[symnum].st_name,
3185 KSYM_NAME_LEN);
3186 strlcpy(module_name, mod->name, MODULE_NAME_LEN);
3187 *exported = is_exported(name, *value, mod);
3188 preempt_enable();
3189 return 0;
3190 }
3191 symnum -= mod->num_symtab;
3192 }
3193 preempt_enable();
3194 return -ERANGE;
3195}
3196
3197static unsigned long mod_find_symname(struct module *mod, const char *name)
3198{
3199 unsigned int i;
3200
3201 for (i = 0; i < mod->num_symtab; i++)
3202 if (strcmp(name, mod->strtab+mod->symtab[i].st_name) == 0 &&
3203 mod->symtab[i].st_info != 'U')
3204 return mod->symtab[i].st_value;
3205 return 0;
3206}
3207
3208/* Look for this name: can be of form module:name. */
3209unsigned long module_kallsyms_lookup_name(const char *name)
3210{
3211 struct module *mod;
3212 char *colon;
3213 unsigned long ret = 0;
3214
3215 /* Don't lock: we're in enough trouble already. */
3216 preempt_disable();
3217 if ((colon = strchr(name, ':')) != NULL) {
3218 *colon = '\0';
3219 if ((mod = find_module(name)) != NULL)
3220 ret = mod_find_symname(mod, colon+1);
3221 *colon = ':';
3222 } else {
3223 list_for_each_entry_rcu(mod, &modules, list)
3224 if ((ret = mod_find_symname(mod, name)) != 0)
3225 break;
3226 }
3227 preempt_enable();
3228 return ret;
3229}
3230
3231int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
3232 struct module *, unsigned long),
3233 void *data)
3234{
3235 struct module *mod;
3236 unsigned int i;
3237 int ret;
3238
3239 list_for_each_entry(mod, &modules, list) {
3240 for (i = 0; i < mod->num_symtab; i++) {
3241 ret = fn(data, mod->strtab + mod->symtab[i].st_name,
3242 mod, mod->symtab[i].st_value);
3243 if (ret != 0)
3244 return ret;
3245 }
3246 }
3247 return 0;
3248}
3249#endif /* CONFIG_KALLSYMS */
3250
3251static char *module_flags(struct module *mod, char *buf)
3252{
3253 int bx = 0;
3254
3255 if (mod->taints ||
3256 mod->state == MODULE_STATE_GOING ||
3257 mod->state == MODULE_STATE_COMING) {
3258 buf[bx++] = '(';
3259 if (mod->taints & (1 << TAINT_PROPRIETARY_MODULE))
3260 buf[bx++] = 'P';
3261 else if (mod->taints & (1 << TAINT_OOT_MODULE))
3262 buf[bx++] = 'O';
3263 if (mod->taints & (1 << TAINT_FORCED_MODULE))
3264 buf[bx++] = 'F';
3265 if (mod->taints & (1 << TAINT_CRAP))
3266 buf[bx++] = 'C';
3267 /*
3268 * TAINT_FORCED_RMMOD: could be added.
3269 * TAINT_UNSAFE_SMP, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't
3270 * apply to modules.
3271 */
3272
3273 /* Show a - for module-is-being-unloaded */
3274 if (mod->state == MODULE_STATE_GOING)
3275 buf[bx++] = '-';
3276 /* Show a + for module-is-being-loaded */
3277 if (mod->state == MODULE_STATE_COMING)
3278 buf[bx++] = '+';
3279 buf[bx++] = ')';
3280 }
3281 buf[bx] = '\0';
3282
3283 return buf;
3284}
3285
3286#ifdef CONFIG_PROC_FS
3287/* Called by the /proc file system to return a list of modules. */
3288static void *m_start(struct seq_file *m, loff_t *pos)
3289{
3290 mutex_lock(&module_mutex);
3291 return seq_list_start(&modules, *pos);
3292}
3293
3294static void *m_next(struct seq_file *m, void *p, loff_t *pos)
3295{
3296 return seq_list_next(p, &modules, pos);
3297}
3298
3299static void m_stop(struct seq_file *m, void *p)
3300{
3301 mutex_unlock(&module_mutex);
3302}
3303
3304static int m_show(struct seq_file *m, void *p)
3305{
3306 struct module *mod = list_entry(p, struct module, list);
3307 char buf[8];
3308
3309 seq_printf(m, "%s %u",
3310 mod->name, mod->init_size + mod->core_size);
3311 print_unload_info(m, mod);
3312
3313 /* Informative for users. */
3314 seq_printf(m, " %s",
3315 mod->state == MODULE_STATE_GOING ? "Unloading":
3316 mod->state == MODULE_STATE_COMING ? "Loading":
3317 "Live");
3318 /* Used by oprofile and other similar tools. */
3319 seq_printf(m, " 0x%pK", mod->module_core);
3320
3321 /* Taints info */
3322 if (mod->taints)
3323 seq_printf(m, " %s", module_flags(mod, buf));
3324
3325 seq_printf(m, "\n");
3326 return 0;
3327}
3328
3329/* Format: modulename size refcount deps address
3330
3331 Where refcount is a number or -, and deps is a comma-separated list
3332 of depends or -.
3333*/
3334static const struct seq_operations modules_op = {
3335 .start = m_start,
3336 .next = m_next,
3337 .stop = m_stop,
3338 .show = m_show
3339};
3340
3341static int modules_open(struct inode *inode, struct file *file)
3342{
3343 return seq_open(file, &modules_op);
3344}
3345
3346static const struct file_operations proc_modules_operations = {
3347 .open = modules_open,
3348 .read = seq_read,
3349 .llseek = seq_lseek,
3350 .release = seq_release,
3351};
3352
3353static int __init proc_modules_init(void)
3354{
3355 proc_create("modules", 0, NULL, &proc_modules_operations);
3356 return 0;
3357}
3358module_init(proc_modules_init);
3359#endif
3360
3361/* Given an address, look for it in the module exception tables. */
3362const struct exception_table_entry *search_module_extables(unsigned long addr)
3363{
3364 const struct exception_table_entry *e = NULL;
3365 struct module *mod;
3366
3367 preempt_disable();
3368 list_for_each_entry_rcu(mod, &modules, list) {
3369 if (mod->num_exentries == 0)
3370 continue;
3371
3372 e = search_extable(mod->extable,
3373 mod->extable + mod->num_exentries - 1,
3374 addr);
3375 if (e)
3376 break;
3377 }
3378 preempt_enable();
3379
3380 /* Now, if we found one, we are running inside it now, hence
3381 we cannot unload the module, hence no refcnt needed. */
3382 return e;
3383}
3384
3385/*
3386 * is_module_address - is this address inside a module?
3387 * @addr: the address to check.
3388 *
3389 * See is_module_text_address() if you simply want to see if the address
3390 * is code (not data).
3391 */
3392bool is_module_address(unsigned long addr)
3393{
3394 bool ret;
3395
3396 preempt_disable();
3397 ret = __module_address(addr) != NULL;
3398 preempt_enable();
3399
3400 return ret;
3401}
3402
3403/*
3404 * __module_address - get the module which contains an address.
3405 * @addr: the address.
3406 *
3407 * Must be called with preempt disabled or module mutex held so that
3408 * module doesn't get freed during this.
3409 */
3410struct module *__module_address(unsigned long addr)
3411{
3412 struct module *mod;
3413
3414 if (addr < module_addr_min || addr > module_addr_max)
3415 return NULL;
3416
3417 list_for_each_entry_rcu(mod, &modules, list)
3418 if (within_module_core(addr, mod)
3419 || within_module_init(addr, mod))
3420 return mod;
3421 return NULL;
3422}
3423EXPORT_SYMBOL_GPL(__module_address);
3424
3425/*
3426 * is_module_text_address - is this address inside module code?
3427 * @addr: the address to check.
3428 *
3429 * See is_module_address() if you simply want to see if the address is
3430 * anywhere in a module. See kernel_text_address() for testing if an
3431 * address corresponds to kernel or module code.
3432 */
3433bool is_module_text_address(unsigned long addr)
3434{
3435 bool ret;
3436
3437 preempt_disable();
3438 ret = __module_text_address(addr) != NULL;
3439 preempt_enable();
3440
3441 return ret;
3442}
3443
3444/*
3445 * __module_text_address - get the module whose code contains an address.
3446 * @addr: the address.
3447 *
3448 * Must be called with preempt disabled or module mutex held so that
3449 * module doesn't get freed during this.
3450 */
3451struct module *__module_text_address(unsigned long addr)
3452{
3453 struct module *mod = __module_address(addr);
3454 if (mod) {
3455 /* Make sure it's within the text section. */
3456 if (!within(addr, mod->module_init, mod->init_text_size)
3457 && !within(addr, mod->module_core, mod->core_text_size))
3458 mod = NULL;
3459 }
3460 return mod;
3461}
3462EXPORT_SYMBOL_GPL(__module_text_address);
3463
3464/* Don't grab lock, we're oopsing. */
3465void print_modules(void)
3466{
3467 struct module *mod;
3468 char buf[8];
3469
3470 printk(KERN_DEFAULT "Modules linked in:");
3471 /* Most callers should already have preempt disabled, but make sure */
3472 preempt_disable();
3473 list_for_each_entry_rcu(mod, &modules, list)
3474 printk(" %s%s", mod->name, module_flags(mod, buf));
3475 preempt_enable();
3476 if (last_unloaded_module[0])
3477 printk(" [last unloaded: %s]", last_unloaded_module);
3478 printk("\n");
3479}
3480
3481#ifdef CONFIG_MODVERSIONS
3482/* Generate the signature for all relevant module structures here.
3483 * If these change, we don't want to try to parse the module. */
3484void module_layout(struct module *mod,
3485 struct modversion_info *ver,
3486 struct kernel_param *kp,
3487 struct kernel_symbol *ks,
3488 struct tracepoint * const *tp)
3489{
3490}
3491EXPORT_SYMBOL(module_layout);
3492#endif
Linux 6.x block layer and io_uring tree(s)