module.c 96.7 KB
Newer Older
1
/*
L
Linus Torvalds 已提交
2
   Copyright (C) 2002 Richard Henderson
3
   Copyright (C) 2001 Rusty Russell, 2002, 2010 Rusty Russell IBM.
L
Linus Torvalds 已提交
4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/
19
#include <linux/export.h>
L
Linus Torvalds 已提交
20
#include <linux/moduleloader.h>
21
#include <linux/ftrace_event.h>
L
Linus Torvalds 已提交
22
#include <linux/init.h>
23
#include <linux/kallsyms.h>
24
#include <linux/file.h>
25
#include <linux/fs.h>
26
#include <linux/sysfs.h>
27
#include <linux/kernel.h>
L
Linus Torvalds 已提交
28 29 30
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/elf.h>
31
#include <linux/proc_fs.h>
32
#include <linux/security.h>
L
Linus Torvalds 已提交
33 34 35 36
#include <linux/seq_file.h>
#include <linux/syscalls.h>
#include <linux/fcntl.h>
#include <linux/rcupdate.h>
37
#include <linux/capability.h>
L
Linus Torvalds 已提交
38 39 40 41 42 43
#include <linux/cpu.h>
#include <linux/moduleparam.h>
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/vermagic.h>
#include <linux/notifier.h>
44
#include <linux/sched.h>
L
Linus Torvalds 已提交
45 46
#include <linux/stop_machine.h>
#include <linux/device.h>
47
#include <linux/string.h>
48
#include <linux/mutex.h>
49
#include <linux/rculist.h>
L
Linus Torvalds 已提交
50 51
#include <asm/uaccess.h>
#include <asm/cacheflush.h>
52
#include <asm/mmu_context.h>
53
#include <linux/license.h>
54
#include <asm/sections.h>
55
#include <linux/tracepoint.h>
56
#include <linux/ftrace.h>
57
#include <linux/async.h>
58
#include <linux/percpu.h>
59
#include <linux/kmemleak.h>
60
#include <linux/jump_label.h>
61
#include <linux/pfn.h>
62
#include <linux/bsearch.h>
D
David Howells 已提交
63
#include <linux/fips.h>
64
#include <uapi/linux/module.h>
65
#include "module-internal.h"
L
Linus Torvalds 已提交
66

67 68 69
#define CREATE_TRACE_POINTS
#include <trace/events/module.h>

L
Linus Torvalds 已提交
70 71 72 73
#ifndef ARCH_SHF_SMALL
#define ARCH_SHF_SMALL 0
#endif

74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93
/*
 * Modules' sections will be aligned on page boundaries
 * to ensure complete separation of code and data, but
 * only when CONFIG_DEBUG_SET_MODULE_RONX=y
 */
#ifdef CONFIG_DEBUG_SET_MODULE_RONX
# define debug_align(X) ALIGN(X, PAGE_SIZE)
#else
# define debug_align(X) (X)
#endif

/*
 * Given BASE and SIZE this macro calculates the number of pages the
 * memory regions occupies
 */
#define MOD_NUMBER_OF_PAGES(BASE, SIZE) (((SIZE) > 0) ?		\
		(PFN_DOWN((unsigned long)(BASE) + (SIZE) - 1) -	\
			 PFN_DOWN((unsigned long)BASE) + 1)	\
		: (0UL))

L
Linus Torvalds 已提交
94 95 96
/* If this is set, the section belongs in the init part of the module */
#define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))

97 98 99 100 101
/*
 * Mutex protects:
 * 1) List of modules (also safely readable with preempt_disable),
 * 2) module_use links,
 * 3) module_addr_min/module_addr_max.
102
 * (delete uses stop_machine/add uses RCU list operations). */
103 104
DEFINE_MUTEX(module_mutex);
EXPORT_SYMBOL_GPL(module_mutex);
L
Linus Torvalds 已提交
105
static LIST_HEAD(modules);
106 107 108 109
#ifdef CONFIG_KGDB_KDB
struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
#endif /* CONFIG_KGDB_KDB */

110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146
#ifdef CONFIG_MODULE_SIG
#ifdef CONFIG_MODULE_SIG_FORCE
static bool sig_enforce = true;
#else
static bool sig_enforce = false;

static int param_set_bool_enable_only(const char *val,
				      const struct kernel_param *kp)
{
	int err;
	bool test;
	struct kernel_param dummy_kp = *kp;

	dummy_kp.arg = &test;

	err = param_set_bool(val, &dummy_kp);
	if (err)
		return err;

	/* Don't let them unset it once it's set! */
	if (!test && sig_enforce)
		return -EROFS;

	if (test)
		sig_enforce = true;
	return 0;
}

static const struct kernel_param_ops param_ops_bool_enable_only = {
	.set = param_set_bool_enable_only,
	.get = param_get_bool,
};
#define param_check_bool_enable_only param_check_bool

module_param(sig_enforce, bool_enable_only, 0644);
#endif /* !CONFIG_MODULE_SIG_FORCE */
#endif /* CONFIG_MODULE_SIG */
L
Linus Torvalds 已提交
147

148 149
/* Block module loading/unloading? */
int modules_disabled = 0;
150
core_param(nomodule, modules_disabled, bint, 0);
151

152 153 154
/* Waiting for a module to finish initializing? */
static DECLARE_WAIT_QUEUE_HEAD(module_wq);

155
static BLOCKING_NOTIFIER_HEAD(module_notify_list);
L
Linus Torvalds 已提交
156

157 158
/* Bounds of module allocation, for speeding __module_address.
 * Protected by module_mutex. */
159 160
static unsigned long module_addr_min = -1UL, module_addr_max = 0;

L
Linus Torvalds 已提交
161 162
int register_module_notifier(struct notifier_block * nb)
{
163
	return blocking_notifier_chain_register(&module_notify_list, nb);
L
Linus Torvalds 已提交
164 165 166 167 168
}
EXPORT_SYMBOL(register_module_notifier);

int unregister_module_notifier(struct notifier_block * nb)
{
169
	return blocking_notifier_chain_unregister(&module_notify_list, nb);
L
Linus Torvalds 已提交
170 171 172
}
EXPORT_SYMBOL(unregister_module_notifier);

173 174 175 176
struct load_info {
	Elf_Ehdr *hdr;
	unsigned long len;
	Elf_Shdr *sechdrs;
177
	char *secstrings, *strtab;
178
	unsigned long symoffs, stroffs;
179 180
	struct _ddebug *debug;
	unsigned int num_debug;
181
	bool sig_ok;
182 183 184 185 186
	struct {
		unsigned int sym, str, mod, vers, info, pcpu;
	} index;
};

187 188
/* We require a truly strong try_module_get(): 0 means failure due to
   ongoing or failed initialization etc. */
L
Linus Torvalds 已提交
189 190
static inline int strong_try_module_get(struct module *mod)
{
191
	BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED);
L
Linus Torvalds 已提交
192
	if (mod && mod->state == MODULE_STATE_COMING)
193 194
		return -EBUSY;
	if (try_module_get(mod))
L
Linus Torvalds 已提交
195
		return 0;
196 197
	else
		return -ENOENT;
L
Linus Torvalds 已提交
198 199
}

200 201
static inline void add_taint_module(struct module *mod, unsigned flag,
				    enum lockdep_ok lockdep_ok)
202
{
203
	add_taint(flag, lockdep_ok);
204
	mod->taints |= (1U << flag);
205 206
}

207 208 209
/*
 * A thread that wants to hold a reference to a module only while it
 * is running can call this to safely exit.  nfsd and lockd use this.
L
Linus Torvalds 已提交
210 211 212 213 214 215 216
 */
void __module_put_and_exit(struct module *mod, long code)
{
	module_put(mod);
	do_exit(code);
}
EXPORT_SYMBOL(__module_put_and_exit);
217

L
Linus Torvalds 已提交
218
/* Find a module section: 0 means not found. */
219
static unsigned int find_sec(const struct load_info *info, const char *name)
L
Linus Torvalds 已提交
220 221 222
{
	unsigned int i;

223 224
	for (i = 1; i < info->hdr->e_shnum; i++) {
		Elf_Shdr *shdr = &info->sechdrs[i];
L
Linus Torvalds 已提交
225
		/* Alloc bit cleared means "ignore it." */
226 227
		if ((shdr->sh_flags & SHF_ALLOC)
		    && strcmp(info->secstrings + shdr->sh_name, name) == 0)
L
Linus Torvalds 已提交
228
			return i;
229
	}
L
Linus Torvalds 已提交
230 231 232
	return 0;
}

233
/* Find a module section, or NULL. */
234
static void *section_addr(const struct load_info *info, const char *name)
235 236
{
	/* Section 0 has sh_addr 0. */
237
	return (void *)info->sechdrs[find_sec(info, name)].sh_addr;
238 239 240
}

/* Find a module section, or NULL.  Fill in number of "objects" in section. */
241
static void *section_objs(const struct load_info *info,
242 243 244 245
			  const char *name,
			  size_t object_size,
			  unsigned int *num)
{
246
	unsigned int sec = find_sec(info, name);
247 248

	/* Section 0 has sh_addr 0 and sh_size 0. */
249 250
	*num = info->sechdrs[sec].sh_size / object_size;
	return (void *)info->sechdrs[sec].sh_addr;
251 252
}

L
Linus Torvalds 已提交
253 254 255 256 257
/* Provided by the linker */
extern const struct kernel_symbol __start___ksymtab[];
extern const struct kernel_symbol __stop___ksymtab[];
extern const struct kernel_symbol __start___ksymtab_gpl[];
extern const struct kernel_symbol __stop___ksymtab_gpl[];
258 259
extern const struct kernel_symbol __start___ksymtab_gpl_future[];
extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
L
Linus Torvalds 已提交
260 261
extern const unsigned long __start___kcrctab[];
extern const unsigned long __start___kcrctab_gpl[];
262
extern const unsigned long __start___kcrctab_gpl_future[];
263 264 265 266 267
#ifdef CONFIG_UNUSED_SYMBOLS
extern const struct kernel_symbol __start___ksymtab_unused[];
extern const struct kernel_symbol __stop___ksymtab_unused[];
extern const struct kernel_symbol __start___ksymtab_unused_gpl[];
extern const struct kernel_symbol __stop___ksymtab_unused_gpl[];
268 269
extern const unsigned long __start___kcrctab_unused[];
extern const unsigned long __start___kcrctab_unused_gpl[];
270
#endif
L
Linus Torvalds 已提交
271 272 273 274

#ifndef CONFIG_MODVERSIONS
#define symversion(base, idx) NULL
#else
275
#define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
L
Linus Torvalds 已提交
276 277
#endif

278 279 280 281 282
static bool each_symbol_in_section(const struct symsearch *arr,
				   unsigned int arrsize,
				   struct module *owner,
				   bool (*fn)(const struct symsearch *syms,
					      struct module *owner,
283
					      void *data),
284
				   void *data)
285
{
286
	unsigned int j;
287

288
	for (j = 0; j < arrsize; j++) {
289 290
		if (fn(&arr[j], owner, data))
			return true;
291
	}
292 293

	return false;
294 295
}

296
/* Returns true as soon as fn returns true, otherwise false. */
297 298 299 300
bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
				    struct module *owner,
				    void *data),
			 void *data)
301 302
{
	struct module *mod;
303
	static const struct symsearch arr[] = {
304
		{ __start___ksymtab, __stop___ksymtab, __start___kcrctab,
305
		  NOT_GPL_ONLY, false },
306
		{ __start___ksymtab_gpl, __stop___ksymtab_gpl,
307 308
		  __start___kcrctab_gpl,
		  GPL_ONLY, false },
309
		{ __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future,
310 311
		  __start___kcrctab_gpl_future,
		  WILL_BE_GPL_ONLY, false },
312
#ifdef CONFIG_UNUSED_SYMBOLS
313
		{ __start___ksymtab_unused, __stop___ksymtab_unused,
314 315
		  __start___kcrctab_unused,
		  NOT_GPL_ONLY, true },
316
		{ __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl,
317 318
		  __start___kcrctab_unused_gpl,
		  GPL_ONLY, true },
319
#endif
320
	};
321

322 323
	if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data))
		return true;
324

325
	list_for_each_entry_rcu(mod, &modules, list) {
326 327
		struct symsearch arr[] = {
			{ mod->syms, mod->syms + mod->num_syms, mod->crcs,
328
			  NOT_GPL_ONLY, false },
329
			{ mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
330 331
			  mod->gpl_crcs,
			  GPL_ONLY, false },
332 333
			{ mod->gpl_future_syms,
			  mod->gpl_future_syms + mod->num_gpl_future_syms,
334 335
			  mod->gpl_future_crcs,
			  WILL_BE_GPL_ONLY, false },
336
#ifdef CONFIG_UNUSED_SYMBOLS
337 338
			{ mod->unused_syms,
			  mod->unused_syms + mod->num_unused_syms,
339 340
			  mod->unused_crcs,
			  NOT_GPL_ONLY, true },
341 342
			{ mod->unused_gpl_syms,
			  mod->unused_gpl_syms + mod->num_unused_gpl_syms,
343 344
			  mod->unused_gpl_crcs,
			  GPL_ONLY, true },
345
#endif
346 347
		};

348 349 350
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;

351 352 353 354 355
		if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data))
			return true;
	}
	return false;
}
356
EXPORT_SYMBOL_GPL(each_symbol_section);
357 358 359 360 361 362 363 364 365 366

struct find_symbol_arg {
	/* Input */
	const char *name;
	bool gplok;
	bool warn;

	/* Output */
	struct module *owner;
	const unsigned long *crc;
367
	const struct kernel_symbol *sym;
368 369
};

370 371 372
static bool check_symbol(const struct symsearch *syms,
				 struct module *owner,
				 unsigned int symnum, void *data)
373 374 375 376 377 378 379 380 381 382
{
	struct find_symbol_arg *fsa = data;

	if (!fsa->gplok) {
		if (syms->licence == GPL_ONLY)
			return false;
		if (syms->licence == WILL_BE_GPL_ONLY && fsa->warn) {
			printk(KERN_WARNING "Symbol %s is being used "
			       "by a non-GPL module, which will not "
			       "be allowed in the future\n", fsa->name);
383
		}
L
Linus Torvalds 已提交
384
	}
385

386
#ifdef CONFIG_UNUSED_SYMBOLS
387 388 389 390 391 392 393 394 395 396 397
	if (syms->unused && fsa->warn) {
		printk(KERN_WARNING "Symbol %s is marked as UNUSED, "
		       "however this module is using it.\n", fsa->name);
		printk(KERN_WARNING
		       "This symbol will go away in the future.\n");
		printk(KERN_WARNING
		       "Please evalute if this is the right api to use and if "
		       "it really is, submit a report the linux kernel "
		       "mailinglist together with submitting your code for "
		       "inclusion.\n");
	}
398
#endif
399 400 401

	fsa->owner = owner;
	fsa->crc = symversion(syms->crcs, symnum);
402
	fsa->sym = &syms->start[symnum];
403 404 405
	return true;
}

406 407 408 409 410 411 412 413
static int cmp_name(const void *va, const void *vb)
{
	const char *a;
	const struct kernel_symbol *b;
	a = va; b = vb;
	return strcmp(a, b->name);
}

414 415 416 417 418
static bool find_symbol_in_section(const struct symsearch *syms,
				   struct module *owner,
				   void *data)
{
	struct find_symbol_arg *fsa = data;
419 420 421 422 423 424 425
	struct kernel_symbol *sym;

	sym = bsearch(fsa->name, syms->start, syms->stop - syms->start,
			sizeof(struct kernel_symbol), cmp_name);

	if (sym != NULL && check_symbol(syms, owner, sym - syms->start, data))
		return true;
426 427 428 429

	return false;
}

430
/* Find a symbol and return it, along with, (optional) crc and
431
 * (optional) module which owns it.  Needs preempt disabled or module_mutex. */
432 433 434 435 436
const struct kernel_symbol *find_symbol(const char *name,
					struct module **owner,
					const unsigned long **crc,
					bool gplok,
					bool warn)
437 438 439 440 441 442 443
{
	struct find_symbol_arg fsa;

	fsa.name = name;
	fsa.gplok = gplok;
	fsa.warn = warn;

444
	if (each_symbol_section(find_symbol_in_section, &fsa)) {
445 446 447 448
		if (owner)
			*owner = fsa.owner;
		if (crc)
			*crc = fsa.crc;
449
		return fsa.sym;
450 451
	}

452
	pr_debug("Failed to find symbol %s\n", name);
453
	return NULL;
L
Linus Torvalds 已提交
454
}
455
EXPORT_SYMBOL_GPL(find_symbol);
L
Linus Torvalds 已提交
456 457

/* Search for module by name: must hold module_mutex. */
458 459
static struct module *find_module_all(const char *name,
				      bool even_unformed)
L
Linus Torvalds 已提交
460 461 462 463
{
	struct module *mod;

	list_for_each_entry(mod, &modules, list) {
464 465
		if (!even_unformed && mod->state == MODULE_STATE_UNFORMED)
			continue;
L
Linus Torvalds 已提交
466 467 468 469 470
		if (strcmp(mod->name, name) == 0)
			return mod;
	}
	return NULL;
}
471 472 473 474 475

struct module *find_module(const char *name)
{
	return find_module_all(name, false);
}
476
EXPORT_SYMBOL_GPL(find_module);
L
Linus Torvalds 已提交
477 478

#ifdef CONFIG_SMP
479

480
static inline void __percpu *mod_percpu(struct module *mod)
481
{
482 483
	return mod->percpu;
}
484

485 486 487
static int percpu_modalloc(struct module *mod,
			   unsigned long size, unsigned long align)
{
488 489
	if (align > PAGE_SIZE) {
		printk(KERN_WARNING "%s: per-cpu alignment %li > %li\n",
490
		       mod->name, align, PAGE_SIZE);
491 492 493
		align = PAGE_SIZE;
	}

494 495
	mod->percpu = __alloc_reserved_percpu(size, align);
	if (!mod->percpu) {
496
		printk(KERN_WARNING
497 498
		       "%s: Could not allocate %lu bytes percpu data\n",
		       mod->name, size);
499 500 501 502
		return -ENOMEM;
	}
	mod->percpu_size = size;
	return 0;
503 504
}

505
static void percpu_modfree(struct module *mod)
506
{
507
	free_percpu(mod->percpu);
508 509
}

510
static unsigned int find_pcpusec(struct load_info *info)
511
{
512
	return find_sec(info, ".data..percpu");
513 514
}

515 516
static void percpu_modcopy(struct module *mod,
			   const void *from, unsigned long size)
517 518 519 520
{
	int cpu;

	for_each_possible_cpu(cpu)
521
		memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
522 523
}

524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540
/**
 * is_module_percpu_address - test whether address is from module static percpu
 * @addr: address to test
 *
 * Test whether @addr belongs to module static percpu area.
 *
 * RETURNS:
 * %true if @addr is from module static percpu area
 */
bool is_module_percpu_address(unsigned long addr)
{
	struct module *mod;
	unsigned int cpu;

	preempt_disable();

	list_for_each_entry_rcu(mod, &modules, list) {
541 542
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
543 544 545 546 547 548 549 550 551 552 553 554 555 556 557
		if (!mod->percpu_size)
			continue;
		for_each_possible_cpu(cpu) {
			void *start = per_cpu_ptr(mod->percpu, cpu);

			if ((void *)addr >= start &&
			    (void *)addr < start + mod->percpu_size) {
				preempt_enable();
				return true;
			}
		}
	}

	preempt_enable();
	return false;
558 559
}

L
Linus Torvalds 已提交
560
#else /* ... !CONFIG_SMP */
561

562
static inline void __percpu *mod_percpu(struct module *mod)
L
Linus Torvalds 已提交
563 564 565
{
	return NULL;
}
566 567 568 569 570 571
static inline int percpu_modalloc(struct module *mod,
				  unsigned long size, unsigned long align)
{
	return -ENOMEM;
}
static inline void percpu_modfree(struct module *mod)
L
Linus Torvalds 已提交
572 573
{
}
574
static unsigned int find_pcpusec(struct load_info *info)
L
Linus Torvalds 已提交
575 576 577
{
	return 0;
}
578 579
static inline void percpu_modcopy(struct module *mod,
				  const void *from, unsigned long size)
L
Linus Torvalds 已提交
580 581 582 583
{
	/* pcpusec should be 0, and size of that section should be 0. */
	BUG_ON(size != 0);
}
584 585 586 587
bool is_module_percpu_address(unsigned long addr)
{
	return false;
}
588

L
Linus Torvalds 已提交
589 590
#endif /* CONFIG_SMP */

591 592 593 594 595 596
#define MODINFO_ATTR(field)	\
static void setup_modinfo_##field(struct module *mod, const char *s)  \
{                                                                     \
	mod->field = kstrdup(s, GFP_KERNEL);                          \
}                                                                     \
static ssize_t show_modinfo_##field(struct module_attribute *mattr,   \
597
			struct module_kobject *mk, char *buffer)      \
598
{                                                                     \
599
	return sprintf(buffer, "%s\n", mk->mod->field);               \
600 601 602 603 604 605 606
}                                                                     \
static int modinfo_##field##_exists(struct module *mod)               \
{                                                                     \
	return mod->field != NULL;                                    \
}                                                                     \
static void free_modinfo_##field(struct module *mod)                  \
{                                                                     \
607 608
	kfree(mod->field);                                            \
	mod->field = NULL;                                            \
609 610
}                                                                     \
static struct module_attribute modinfo_##field = {                    \
611
	.attr = { .name = __stringify(field), .mode = 0444 },         \
612 613 614 615 616 617 618 619 620
	.show = show_modinfo_##field,                                 \
	.setup = setup_modinfo_##field,                               \
	.test = modinfo_##field##_exists,                             \
	.free = free_modinfo_##field,                                 \
};

MODINFO_ATTR(version);
MODINFO_ATTR(srcversion);

621 622
static char last_unloaded_module[MODULE_NAME_LEN+1];

623
#ifdef CONFIG_MODULE_UNLOAD
624 625 626

EXPORT_TRACEPOINT_SYMBOL(module_get);

L
Linus Torvalds 已提交
627
/* Init the unload section of the module. */
628
static int module_unload_init(struct module *mod)
L
Linus Torvalds 已提交
629
{
630 631 632 633
	mod->refptr = alloc_percpu(struct module_ref);
	if (!mod->refptr)
		return -ENOMEM;

634 635
	INIT_LIST_HEAD(&mod->source_list);
	INIT_LIST_HEAD(&mod->target_list);
636

L
Linus Torvalds 已提交
637
	/* Hold reference count during initialization. */
638
	__this_cpu_write(mod->refptr->incs, 1);
L
Linus Torvalds 已提交
639 640
	/* Backwards compatibility macros put refcount during init. */
	mod->waiter = current;
641 642

	return 0;
L
Linus Torvalds 已提交
643 644 645 646 647 648 649
}

/* Does a already use b? */
static int already_uses(struct module *a, struct module *b)
{
	struct module_use *use;

650 651
	list_for_each_entry(use, &b->source_list, source_list) {
		if (use->source == a) {
652
			pr_debug("%s uses %s!\n", a->name, b->name);
L
Linus Torvalds 已提交
653 654 655
			return 1;
		}
	}
656
	pr_debug("%s does not use %s!\n", a->name, b->name);
L
Linus Torvalds 已提交
657 658 659
	return 0;
}

660 661 662 663 664 665 666 667 668 669 670
/*
 * Module a uses b
 *  - we add 'a' as a "source", 'b' as a "target" of module use
 *  - the module_use is added to the list of 'b' sources (so
 *    'b' can walk the list to see who sourced them), and of 'a'
 *    targets (so 'a' can see what modules it targets).
 */
static int add_module_usage(struct module *a, struct module *b)
{
	struct module_use *use;

671
	pr_debug("Allocating new usage for %s.\n", a->name);
672 673 674 675 676 677 678 679 680 681 682 683 684
	use = kmalloc(sizeof(*use), GFP_ATOMIC);
	if (!use) {
		printk(KERN_WARNING "%s: out of memory loading\n", a->name);
		return -ENOMEM;
	}

	use->source = a;
	use->target = b;
	list_add(&use->source_list, &b->source_list);
	list_add(&use->target_list, &a->target_list);
	return 0;
}

685
/* Module a uses b: caller needs module_mutex() */
686
int ref_module(struct module *a, struct module *b)
L
Linus Torvalds 已提交
687
{
688
	int err;
K
Kay Sievers 已提交
689

690
	if (b == NULL || already_uses(a, b))
691 692
		return 0;

693 694
	/* If module isn't available, we fail. */
	err = strong_try_module_get(b);
695
	if (err)
696
		return err;
L
Linus Torvalds 已提交
697

698 699
	err = add_module_usage(a, b);
	if (err) {
L
Linus Torvalds 已提交
700
		module_put(b);
701
		return err;
L
Linus Torvalds 已提交
702
	}
703
	return 0;
L
Linus Torvalds 已提交
704
}
705
EXPORT_SYMBOL_GPL(ref_module);
L
Linus Torvalds 已提交
706 707 708 709

/* Clear the unload stuff of the module. */
static void module_unload_free(struct module *mod)
{
710
	struct module_use *use, *tmp;
L
Linus Torvalds 已提交
711

712
	mutex_lock(&module_mutex);
713 714
	list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
		struct module *i = use->target;
715
		pr_debug("%s unusing %s\n", mod->name, i->name);
716 717 718 719
		module_put(i);
		list_del(&use->source_list);
		list_del(&use->target_list);
		kfree(use);
L
Linus Torvalds 已提交
720
	}
721
	mutex_unlock(&module_mutex);
722 723

	free_percpu(mod->refptr);
L
Linus Torvalds 已提交
724 725 726
}

#ifdef CONFIG_MODULE_FORCE_UNLOAD
727
static inline int try_force_unload(unsigned int flags)
L
Linus Torvalds 已提交
728 729 730
{
	int ret = (flags & O_TRUNC);
	if (ret)
731
		add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE);
L
Linus Torvalds 已提交
732 733 734
	return ret;
}
#else
735
static inline int try_force_unload(unsigned int flags)
L
Linus Torvalds 已提交
736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752
{
	return 0;
}
#endif /* CONFIG_MODULE_FORCE_UNLOAD */

struct stopref
{
	struct module *mod;
	int flags;
	int *forced;
};

/* Whole machine is stopped with interrupts off when this runs. */
static int __try_stop_module(void *_sref)
{
	struct stopref *sref = _sref;

753 754
	/* If it's not unused, quit unless we're forcing. */
	if (module_refcount(sref->mod) != 0) {
755
		if (!(*sref->forced = try_force_unload(sref->flags)))
L
Linus Torvalds 已提交
756 757 758 759 760 761 762 763 764 765
			return -EWOULDBLOCK;
	}

	/* Mark it as dying. */
	sref->mod->state = MODULE_STATE_GOING;
	return 0;
}

static int try_stop_module(struct module *mod, int flags, int *forced)
{
766 767
	if (flags & O_NONBLOCK) {
		struct stopref sref = { mod, flags, forced };
L
Linus Torvalds 已提交
768

769
		return stop_machine(__try_stop_module, &sref, NULL);
770 771 772 773 774 775
	} else {
		/* We don't need to stop the machine for this. */
		mod->state = MODULE_STATE_GOING;
		synchronize_sched();
		return 0;
	}
L
Linus Torvalds 已提交
776 777
}

778
unsigned long module_refcount(struct module *mod)
L
Linus Torvalds 已提交
779
{
780
	unsigned long incs = 0, decs = 0;
781
	int cpu;
L
Linus Torvalds 已提交
782

783
	for_each_possible_cpu(cpu)
784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801
		decs += per_cpu_ptr(mod->refptr, cpu)->decs;
	/*
	 * ensure the incs are added up after the decs.
	 * module_put ensures incs are visible before decs with smp_wmb.
	 *
	 * This 2-count scheme avoids the situation where the refcount
	 * for CPU0 is read, then CPU0 increments the module refcount,
	 * then CPU1 drops that refcount, then the refcount for CPU1 is
	 * read. We would record a decrement but not its corresponding
	 * increment so we would see a low count (disaster).
	 *
	 * Rare situation? But module_refcount can be preempted, and we
	 * might be tallying up 4096+ CPUs. So it is not impossible.
	 */
	smp_rmb();
	for_each_possible_cpu(cpu)
		incs += per_cpu_ptr(mod->refptr, cpu)->incs;
	return incs - decs;
L
Linus Torvalds 已提交
802 803 804 805 806 807 808 809
}
EXPORT_SYMBOL(module_refcount);

/* This exists whether we can unload or not */
static void free_module(struct module *mod);

static void wait_for_zero_refcount(struct module *mod)
{
810
	/* Since we might sleep for some time, release the mutex first */
811
	mutex_unlock(&module_mutex);
L
Linus Torvalds 已提交
812
	for (;;) {
813
		pr_debug("Looking at refcount...\n");
L
Linus Torvalds 已提交
814 815 816 817 818 819
		set_current_state(TASK_UNINTERRUPTIBLE);
		if (module_refcount(mod) == 0)
			break;
		schedule();
	}
	current->state = TASK_RUNNING;
820
	mutex_lock(&module_mutex);
L
Linus Torvalds 已提交
821 822
}

823 824
SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
		unsigned int, flags)
L
Linus Torvalds 已提交
825 826
{
	struct module *mod;
827
	char name[MODULE_NAME_LEN];
L
Linus Torvalds 已提交
828 829
	int ret, forced = 0;

830
	if (!capable(CAP_SYS_MODULE) || modules_disabled)
831 832 833 834 835 836
		return -EPERM;

	if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
		return -EFAULT;
	name[MODULE_NAME_LEN-1] = '\0';

837 838
	if (mutex_lock_interruptible(&module_mutex) != 0)
		return -EINTR;
L
Linus Torvalds 已提交
839 840 841 842 843 844 845

	mod = find_module(name);
	if (!mod) {
		ret = -ENOENT;
		goto out;
	}

846
	if (!list_empty(&mod->source_list)) {
L
Linus Torvalds 已提交
847 848 849 850 851 852 853 854 855
		/* Other modules depend on us: get rid of them first. */
		ret = -EWOULDBLOCK;
		goto out;
	}

	/* Doing init or already dying? */
	if (mod->state != MODULE_STATE_LIVE) {
		/* FIXME: if (force), slam module count and wake up
                   waiter --RR */
856
		pr_debug("%s already dying\n", mod->name);
L
Linus Torvalds 已提交
857 858 859 860 861
		ret = -EBUSY;
		goto out;
	}

	/* If it has an init func, it must have an exit func to unload */
862
	if (mod->init && !mod->exit) {
863
		forced = try_force_unload(flags);
L
Linus Torvalds 已提交
864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882
		if (!forced) {
			/* This module can't be removed */
			ret = -EBUSY;
			goto out;
		}
	}

	/* Set this up before setting mod->state */
	mod->waiter = current;

	/* Stop the machine so refcounts can't move and disable module. */
	ret = try_stop_module(mod, flags, &forced);
	if (ret != 0)
		goto out;

	/* Never wait if forced. */
	if (!forced && module_refcount(mod) != 0)
		wait_for_zero_refcount(mod);

883
	mutex_unlock(&module_mutex);
L
Lucas De Marchi 已提交
884
	/* Final destruction now no one is using it. */
885
	if (mod->exit != NULL)
L
Linus Torvalds 已提交
886
		mod->exit();
887 888
	blocking_notifier_call_chain(&module_notify_list,
				     MODULE_STATE_GOING, mod);
889
	async_synchronize_full();
890

891
	/* Store the name of the last unloaded module for diagnostic purposes */
892
	strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
L
Linus Torvalds 已提交
893

894 895 896
	free_module(mod);
	return 0;
out:
897
	mutex_unlock(&module_mutex);
L
Linus Torvalds 已提交
898 899 900
	return ret;
}

901
static inline void print_unload_info(struct seq_file *m, struct module *mod)
L
Linus Torvalds 已提交
902 903 904 905
{
	struct module_use *use;
	int printed_something = 0;

906
	seq_printf(m, " %lu ", module_refcount(mod));
L
Linus Torvalds 已提交
907 908 909

	/* Always include a trailing , so userspace can differentiate
           between this and the old multi-field proc format. */
910
	list_for_each_entry(use, &mod->source_list, source_list) {
L
Linus Torvalds 已提交
911
		printed_something = 1;
912
		seq_printf(m, "%s,", use->source->name);
L
Linus Torvalds 已提交
913 914 915 916 917 918 919 920 921 922 923 924 925 926 927
	}

	if (mod->init != NULL && mod->exit == NULL) {
		printed_something = 1;
		seq_printf(m, "[permanent],");
	}

	if (!printed_something)
		seq_printf(m, "-");
}

void __symbol_put(const char *symbol)
{
	struct module *owner;

928
	preempt_disable();
929
	if (!find_symbol(symbol, &owner, NULL, true, false))
L
Linus Torvalds 已提交
930 931
		BUG();
	module_put(owner);
932
	preempt_enable();
L
Linus Torvalds 已提交
933 934 935
}
EXPORT_SYMBOL(__symbol_put);

936
/* Note this assumes addr is a function, which it currently always is. */
L
Linus Torvalds 已提交
937 938
void symbol_put_addr(void *addr)
{
939
	struct module *modaddr;
940
	unsigned long a = (unsigned long)dereference_function_descriptor(addr);
L
Linus Torvalds 已提交
941

942
	if (core_kernel_text(a))
943
		return;
L
Linus Torvalds 已提交
944

945 946
	/* module_text_address is safe here: we're supposed to have reference
	 * to module from symbol_get, so it can't go away. */
947
	modaddr = __module_text_address(a);
948
	BUG_ON(!modaddr);
949
	module_put(modaddr);
L
Linus Torvalds 已提交
950 951 952 953
}
EXPORT_SYMBOL_GPL(symbol_put_addr);

static ssize_t show_refcnt(struct module_attribute *mattr,
954
			   struct module_kobject *mk, char *buffer)
L
Linus Torvalds 已提交
955
{
956
	return sprintf(buffer, "%lu\n", module_refcount(mk->mod));
L
Linus Torvalds 已提交
957 958
}

959 960
static struct module_attribute modinfo_refcnt =
	__ATTR(refcnt, 0444, show_refcnt, NULL);
L
Linus Torvalds 已提交
961

962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991
void __module_get(struct module *module)
{
	if (module) {
		preempt_disable();
		__this_cpu_inc(module->refptr->incs);
		trace_module_get(module, _RET_IP_);
		preempt_enable();
	}
}
EXPORT_SYMBOL(__module_get);

bool try_module_get(struct module *module)
{
	bool ret = true;

	if (module) {
		preempt_disable();

		if (likely(module_is_live(module))) {
			__this_cpu_inc(module->refptr->incs);
			trace_module_get(module, _RET_IP_);
		} else
			ret = false;

		preempt_enable();
	}
	return ret;
}
EXPORT_SYMBOL(try_module_get);

992 993 994
void module_put(struct module *module)
{
	if (module) {
995
		preempt_disable();
996 997
		smp_wmb(); /* see comment in module_refcount */
		__this_cpu_inc(module->refptr->decs);
998

999
		trace_module_put(module, _RET_IP_);
1000 1001 1002
		/* Maybe they're waiting for us to drop reference? */
		if (unlikely(!module_is_live(module)))
			wake_up_process(module->waiter);
1003
		preempt_enable();
1004 1005 1006 1007
	}
}
EXPORT_SYMBOL(module_put);

L
Linus Torvalds 已提交
1008
#else /* !CONFIG_MODULE_UNLOAD */
1009
static inline void print_unload_info(struct seq_file *m, struct module *mod)
L
Linus Torvalds 已提交
1010 1011 1012 1013 1014 1015 1016 1017 1018
{
	/* We don't know the usage count, or what modules are using. */
	seq_printf(m, " - -");
}

static inline void module_unload_free(struct module *mod)
{
}

1019
int ref_module(struct module *a, struct module *b)
L
Linus Torvalds 已提交
1020
{
1021
	return strong_try_module_get(b);
L
Linus Torvalds 已提交
1022
}
1023
EXPORT_SYMBOL_GPL(ref_module);
L
Linus Torvalds 已提交
1024

1025
static inline int module_unload_init(struct module *mod)
L
Linus Torvalds 已提交
1026
{
1027
	return 0;
L
Linus Torvalds 已提交
1028 1029 1030
}
#endif /* CONFIG_MODULE_UNLOAD */

1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050
static size_t module_flags_taint(struct module *mod, char *buf)
{
	size_t l = 0;

	if (mod->taints & (1 << TAINT_PROPRIETARY_MODULE))
		buf[l++] = 'P';
	if (mod->taints & (1 << TAINT_OOT_MODULE))
		buf[l++] = 'O';
	if (mod->taints & (1 << TAINT_FORCED_MODULE))
		buf[l++] = 'F';
	if (mod->taints & (1 << TAINT_CRAP))
		buf[l++] = 'C';
	/*
	 * TAINT_FORCED_RMMOD: could be added.
	 * TAINT_UNSAFE_SMP, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't
	 * apply to modules.
	 */
	return l;
}

1051
static ssize_t show_initstate(struct module_attribute *mattr,
1052
			      struct module_kobject *mk, char *buffer)
1053 1054 1055
{
	const char *state = "unknown";

1056
	switch (mk->mod->state) {
1057 1058 1059 1060 1061 1062 1063 1064 1065
	case MODULE_STATE_LIVE:
		state = "live";
		break;
	case MODULE_STATE_COMING:
		state = "coming";
		break;
	case MODULE_STATE_GOING:
		state = "going";
		break;
1066 1067
	default:
		BUG();
1068 1069 1070 1071
	}
	return sprintf(buffer, "%s\n", state);
}

1072 1073
static struct module_attribute modinfo_initstate =
	__ATTR(initstate, 0444, show_initstate, NULL);
1074

1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085
static ssize_t store_uevent(struct module_attribute *mattr,
			    struct module_kobject *mk,
			    const char *buffer, size_t count)
{
	enum kobject_action action;

	if (kobject_action_type(buffer, count, &action) == 0)
		kobject_uevent(&mk->kobj, action);
	return count;
}

1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118
struct module_attribute module_uevent =
	__ATTR(uevent, 0200, NULL, store_uevent);

static ssize_t show_coresize(struct module_attribute *mattr,
			     struct module_kobject *mk, char *buffer)
{
	return sprintf(buffer, "%u\n", mk->mod->core_size);
}

static struct module_attribute modinfo_coresize =
	__ATTR(coresize, 0444, show_coresize, NULL);

static ssize_t show_initsize(struct module_attribute *mattr,
			     struct module_kobject *mk, char *buffer)
{
	return sprintf(buffer, "%u\n", mk->mod->init_size);
}

static struct module_attribute modinfo_initsize =
	__ATTR(initsize, 0444, show_initsize, NULL);

static ssize_t show_taint(struct module_attribute *mattr,
			  struct module_kobject *mk, char *buffer)
{
	size_t l;

	l = module_flags_taint(mk->mod, buffer);
	buffer[l++] = '\n';
	return l;
}

static struct module_attribute modinfo_taint =
	__ATTR(taint, 0444, show_taint, NULL);
1119

1120
static struct module_attribute *modinfo_attrs[] = {
1121
	&module_uevent,
1122 1123
	&modinfo_version,
	&modinfo_srcversion,
1124 1125 1126 1127
	&modinfo_initstate,
	&modinfo_coresize,
	&modinfo_initsize,
	&modinfo_taint,
1128
#ifdef CONFIG_MODULE_UNLOAD
1129
	&modinfo_refcnt,
1130 1131 1132 1133
#endif
	NULL,
};

L
Linus Torvalds 已提交
1134 1135
static const char vermagic[] = VERMAGIC_STRING;

1136
static int try_to_force_load(struct module *mod, const char *reason)
1137 1138
{
#ifdef CONFIG_MODULE_FORCE_LOAD
1139
	if (!test_taint(TAINT_FORCED_MODULE))
1140 1141
		printk(KERN_WARNING "%s: %s: kernel tainted.\n",
		       mod->name, reason);
1142
	add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
1143 1144 1145 1146 1147 1148
	return 0;
#else
	return -ENOEXEC;
#endif
}

L
Linus Torvalds 已提交
1149
#ifdef CONFIG_MODVERSIONS
1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160
/* If the arch applies (non-zero) relocations to kernel kcrctab, unapply it. */
static unsigned long maybe_relocated(unsigned long crc,
				     const struct module *crc_owner)
{
#ifdef ARCH_RELOCATES_KCRCTAB
	if (crc_owner == NULL)
		return crc - (unsigned long)reloc_start;
#endif
	return crc;
}

L
Linus Torvalds 已提交
1161 1162 1163 1164
static int check_version(Elf_Shdr *sechdrs,
			 unsigned int versindex,
			 const char *symname,
			 struct module *mod, 
1165 1166
			 const unsigned long *crc,
			 const struct module *crc_owner)
L
Linus Torvalds 已提交
1167 1168 1169 1170 1171 1172 1173 1174
{
	unsigned int i, num_versions;
	struct modversion_info *versions;

	/* Exporting module didn't supply crcs?  OK, we're already tainted. */
	if (!crc)
		return 1;

1175 1176 1177 1178
	/* No versions at all?  modprobe --force does this. */
	if (versindex == 0)
		return try_to_force_load(mod, symname) == 0;

L
Linus Torvalds 已提交
1179 1180 1181 1182 1183 1184 1185 1186
	versions = (void *) sechdrs[versindex].sh_addr;
	num_versions = sechdrs[versindex].sh_size
		/ sizeof(struct modversion_info);

	for (i = 0; i < num_versions; i++) {
		if (strcmp(versions[i].name, symname) != 0)
			continue;

1187
		if (versions[i].crc == maybe_relocated(*crc, crc_owner))
L
Linus Torvalds 已提交
1188
			return 1;
1189
		pr_debug("Found checksum %lX vs module %lX\n",
1190
		       maybe_relocated(*crc, crc_owner), versions[i].crc);
1191
		goto bad_version;
L
Linus Torvalds 已提交
1192
	}
1193

1194 1195 1196
	printk(KERN_WARNING "%s: no symbol version for %s\n",
	       mod->name, symname);
	return 0;
1197 1198 1199 1200 1201

bad_version:
	printk("%s: disagrees about version of symbol %s\n",
	       mod->name, symname);
	return 0;
L
Linus Torvalds 已提交
1202 1203 1204 1205 1206 1207 1208 1209
}

static inline int check_modstruct_version(Elf_Shdr *sechdrs,
					  unsigned int versindex,
					  struct module *mod)
{
	const unsigned long *crc;

1210 1211
	/* Since this should be found in kernel (which can't be removed),
	 * no locking is necessary. */
1212 1213
	if (!find_symbol(MODULE_SYMBOL_PREFIX "module_layout", NULL,
			 &crc, true, false))
L
Linus Torvalds 已提交
1214
		BUG();
1215 1216
	return check_version(sechdrs, versindex, "module_layout", mod, crc,
			     NULL);
L
Linus Torvalds 已提交
1217 1218
}

1219 1220 1221
/* First part is kernel version, which we ignore if module has crcs. */
static inline int same_magic(const char *amagic, const char *bmagic,
			     bool has_crcs)
L
Linus Torvalds 已提交
1222
{
1223 1224 1225 1226
	if (has_crcs) {
		amagic += strcspn(amagic, " ");
		bmagic += strcspn(bmagic, " ");
	}
L
Linus Torvalds 已提交
1227 1228 1229 1230 1231 1232 1233
	return strcmp(amagic, bmagic) == 0;
}
#else
static inline int check_version(Elf_Shdr *sechdrs,
				unsigned int versindex,
				const char *symname,
				struct module *mod, 
1234 1235
				const unsigned long *crc,
				const struct module *crc_owner)
L
Linus Torvalds 已提交
1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246
{
	return 1;
}

static inline int check_modstruct_version(Elf_Shdr *sechdrs,
					  unsigned int versindex,
					  struct module *mod)
{
	return 1;
}

1247 1248
static inline int same_magic(const char *amagic, const char *bmagic,
			     bool has_crcs)
L
Linus Torvalds 已提交
1249 1250 1251 1252 1253
{
	return strcmp(amagic, bmagic) == 0;
}
#endif /* CONFIG_MODVERSIONS */

1254
/* Resolve a symbol for this module.  I.e. if we find one, record usage. */
1255 1256
static const struct kernel_symbol *resolve_symbol(struct module *mod,
						  const struct load_info *info,
1257
						  const char *name,
1258
						  char ownername[])
L
Linus Torvalds 已提交
1259 1260
{
	struct module *owner;
1261
	const struct kernel_symbol *sym;
L
Linus Torvalds 已提交
1262
	const unsigned long *crc;
1263
	int err;
L
Linus Torvalds 已提交
1264

1265
	mutex_lock(&module_mutex);
1266
	sym = find_symbol(name, &owner, &crc,
1267
			  !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
1268 1269 1270
	if (!sym)
		goto unlock;

1271 1272
	if (!check_version(info->sechdrs, info->index.vers, name, mod, crc,
			   owner)) {
1273 1274
		sym = ERR_PTR(-EINVAL);
		goto getname;
L
Linus Torvalds 已提交
1275
	}
1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286

	err = ref_module(mod, owner);
	if (err) {
		sym = ERR_PTR(err);
		goto getname;
	}

getname:
	/* We must make copy under the lock if we failed to get ref. */
	strncpy(ownername, module_name(owner), MODULE_NAME_LEN);
unlock:
1287
	mutex_unlock(&module_mutex);
1288
	return sym;
L
Linus Torvalds 已提交
1289 1290
}

1291 1292 1293 1294
static const struct kernel_symbol *
resolve_symbol_wait(struct module *mod,
		    const struct load_info *info,
		    const char *name)
1295 1296
{
	const struct kernel_symbol *ksym;
1297
	char owner[MODULE_NAME_LEN];
1298 1299

	if (wait_event_interruptible_timeout(module_wq,
1300 1301
			!IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
			|| PTR_ERR(ksym) != -EBUSY,
1302 1303
					     30 * HZ) <= 0) {
		printk(KERN_WARNING "%s: gave up waiting for init of module %s.\n",
1304
		       mod->name, owner);
1305 1306 1307 1308
	}
	return ksym;
}

L
Linus Torvalds 已提交
1309 1310 1311 1312
/*
 * /sys/module/foo/sections stuff
 * J. Corbet <corbet@lwn.net>
 */
R
Rusty Russell 已提交
1313
#ifdef CONFIG_SYSFS
1314

R
Rusty Russell 已提交
1315
#ifdef CONFIG_KALLSYMS
1316 1317 1318 1319 1320
static inline bool sect_empty(const Elf_Shdr *sect)
{
	return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
}

1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334
struct module_sect_attr
{
	struct module_attribute mattr;
	char *name;
	unsigned long address;
};

struct module_sect_attrs
{
	struct attribute_group grp;
	unsigned int nsections;
	struct module_sect_attr attrs[0];
};

L
Linus Torvalds 已提交
1335
static ssize_t module_sect_show(struct module_attribute *mattr,
1336
				struct module_kobject *mk, char *buf)
L
Linus Torvalds 已提交
1337 1338 1339
{
	struct module_sect_attr *sattr =
		container_of(mattr, struct module_sect_attr, mattr);
1340
	return sprintf(buf, "0x%pK\n", (void *)sattr->address);
L
Linus Torvalds 已提交
1341 1342
}

1343 1344
static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
{
1345
	unsigned int section;
1346 1347 1348 1349 1350 1351

	for (section = 0; section < sect_attrs->nsections; section++)
		kfree(sect_attrs->attrs[section].name);
	kfree(sect_attrs);
}

R
Rusty Russell 已提交
1352
static void add_sect_attrs(struct module *mod, const struct load_info *info)
L
Linus Torvalds 已提交
1353 1354 1355 1356 1357
{
	unsigned int nloaded = 0, i, size[2];
	struct module_sect_attrs *sect_attrs;
	struct module_sect_attr *sattr;
	struct attribute **gattr;
1358

L
Linus Torvalds 已提交
1359
	/* Count loaded sections and allocate structures */
R
Rusty Russell 已提交
1360 1361
	for (i = 0; i < info->hdr->e_shnum; i++)
		if (!sect_empty(&info->sechdrs[i]))
L
Linus Torvalds 已提交
1362 1363 1364 1365 1366
			nloaded++;
	size[0] = ALIGN(sizeof(*sect_attrs)
			+ nloaded * sizeof(sect_attrs->attrs[0]),
			sizeof(sect_attrs->grp.attrs[0]));
	size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]);
1367 1368
	sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
	if (sect_attrs == NULL)
L
Linus Torvalds 已提交
1369 1370 1371 1372 1373 1374
		return;

	/* Setup section attributes. */
	sect_attrs->grp.name = "sections";
	sect_attrs->grp.attrs = (void *)sect_attrs + size[0];

1375
	sect_attrs->nsections = 0;
L
Linus Torvalds 已提交
1376 1377
	sattr = &sect_attrs->attrs[0];
	gattr = &sect_attrs->grp.attrs[0];
R
Rusty Russell 已提交
1378 1379 1380
	for (i = 0; i < info->hdr->e_shnum; i++) {
		Elf_Shdr *sec = &info->sechdrs[i];
		if (sect_empty(sec))
1381
			continue;
R
Rusty Russell 已提交
1382 1383
		sattr->address = sec->sh_addr;
		sattr->name = kstrdup(info->secstrings + sec->sh_name,
1384 1385 1386 1387
					GFP_KERNEL);
		if (sattr->name == NULL)
			goto out;
		sect_attrs->nsections++;
1388
		sysfs_attr_init(&sattr->mattr.attr);
L
Linus Torvalds 已提交
1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402
		sattr->mattr.show = module_sect_show;
		sattr->mattr.store = NULL;
		sattr->mattr.attr.name = sattr->name;
		sattr->mattr.attr.mode = S_IRUGO;
		*(gattr++) = &(sattr++)->mattr.attr;
	}
	*gattr = NULL;

	if (sysfs_create_group(&mod->mkobj.kobj, &sect_attrs->grp))
		goto out;

	mod->sect_attrs = sect_attrs;
	return;
  out:
1403
	free_sect_attrs(sect_attrs);
L
Linus Torvalds 已提交
1404 1405 1406 1407 1408 1409 1410 1411 1412
}

static void remove_sect_attrs(struct module *mod)
{
	if (mod->sect_attrs) {
		sysfs_remove_group(&mod->mkobj.kobj,
				   &mod->sect_attrs->grp);
		/* We are positive that no one is using any sect attrs
		 * at this point.  Deallocate immediately. */
1413
		free_sect_attrs(mod->sect_attrs);
L
Linus Torvalds 已提交
1414 1415 1416 1417
		mod->sect_attrs = NULL;
	}
}

1418 1419 1420 1421 1422 1423 1424 1425 1426 1427
/*
 * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
 */

struct module_notes_attrs {
	struct kobject *dir;
	unsigned int notes;
	struct bin_attribute attrs[0];
};

1428
static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445
				 struct bin_attribute *bin_attr,
				 char *buf, loff_t pos, size_t count)
{
	/*
	 * The caller checked the pos and count against our size.
	 */
	memcpy(buf, bin_attr->private + pos, count);
	return count;
}

static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
			     unsigned int i)
{
	if (notes_attrs->dir) {
		while (i-- > 0)
			sysfs_remove_bin_file(notes_attrs->dir,
					      &notes_attrs->attrs[i]);
1446
		kobject_put(notes_attrs->dir);
1447 1448 1449 1450
	}
	kfree(notes_attrs);
}

R
Rusty Russell 已提交
1451
static void add_notes_attrs(struct module *mod, const struct load_info *info)
1452 1453 1454 1455 1456
{
	unsigned int notes, loaded, i;
	struct module_notes_attrs *notes_attrs;
	struct bin_attribute *nattr;

1457 1458 1459 1460
	/* failed to create section attributes, so can't create notes */
	if (!mod->sect_attrs)
		return;

1461 1462
	/* Count notes sections and allocate structures.  */
	notes = 0;
R
Rusty Russell 已提交
1463 1464 1465
	for (i = 0; i < info->hdr->e_shnum; i++)
		if (!sect_empty(&info->sechdrs[i]) &&
		    (info->sechdrs[i].sh_type == SHT_NOTE))
1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478
			++notes;

	if (notes == 0)
		return;

	notes_attrs = kzalloc(sizeof(*notes_attrs)
			      + notes * sizeof(notes_attrs->attrs[0]),
			      GFP_KERNEL);
	if (notes_attrs == NULL)
		return;

	notes_attrs->notes = notes;
	nattr = &notes_attrs->attrs[0];
R
Rusty Russell 已提交
1479 1480
	for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
		if (sect_empty(&info->sechdrs[i]))
1481
			continue;
R
Rusty Russell 已提交
1482
		if (info->sechdrs[i].sh_type == SHT_NOTE) {
1483
			sysfs_bin_attr_init(nattr);
1484 1485
			nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
			nattr->attr.mode = S_IRUGO;
R
Rusty Russell 已提交
1486 1487
			nattr->size = info->sechdrs[i].sh_size;
			nattr->private = (void *) info->sechdrs[i].sh_addr;
1488 1489 1490 1491 1492 1493
			nattr->read = module_notes_read;
			++nattr;
		}
		++loaded;
	}

1494
	notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515
	if (!notes_attrs->dir)
		goto out;

	for (i = 0; i < notes; ++i)
		if (sysfs_create_bin_file(notes_attrs->dir,
					  &notes_attrs->attrs[i]))
			goto out;

	mod->notes_attrs = notes_attrs;
	return;

  out:
	free_notes_attrs(notes_attrs, i);
}

static void remove_notes_attrs(struct module *mod)
{
	if (mod->notes_attrs)
		free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
}

L
Linus Torvalds 已提交
1516
#else
1517

R
Rusty Russell 已提交
1518 1519
static inline void add_sect_attrs(struct module *mod,
				  const struct load_info *info)
L
Linus Torvalds 已提交
1520 1521 1522 1523 1524 1525
{
}

static inline void remove_sect_attrs(struct module *mod)
{
}
1526

R
Rusty Russell 已提交
1527 1528
static inline void add_notes_attrs(struct module *mod,
				   const struct load_info *info)
1529 1530 1531 1532 1533 1534
{
}

static inline void remove_notes_attrs(struct module *mod)
{
}
R
Rusty Russell 已提交
1535
#endif /* CONFIG_KALLSYMS */
L
Linus Torvalds 已提交
1536

1537 1538 1539 1540 1541 1542
static void add_usage_links(struct module *mod)
{
#ifdef CONFIG_MODULE_UNLOAD
	struct module_use *use;
	int nowarn;

1543
	mutex_lock(&module_mutex);
1544 1545 1546 1547
	list_for_each_entry(use, &mod->target_list, target_list) {
		nowarn = sysfs_create_link(use->target->holders_dir,
					   &mod->mkobj.kobj, mod->name);
	}
1548
	mutex_unlock(&module_mutex);
1549 1550 1551 1552 1553 1554 1555 1556
#endif
}

static void del_usage_links(struct module *mod)
{
#ifdef CONFIG_MODULE_UNLOAD
	struct module_use *use;

1557
	mutex_lock(&module_mutex);
1558 1559
	list_for_each_entry(use, &mod->target_list, target_list)
		sysfs_remove_link(use->target->holders_dir, mod->name);
1560
	mutex_unlock(&module_mutex);
1561 1562 1563
#endif
}

1564
static int module_add_modinfo_attrs(struct module *mod)
1565 1566
{
	struct module_attribute *attr;
1567
	struct module_attribute *temp_attr;
1568 1569 1570
	int error = 0;
	int i;

1571 1572 1573 1574 1575 1576 1577
	mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
					(ARRAY_SIZE(modinfo_attrs) + 1)),
					GFP_KERNEL);
	if (!mod->modinfo_attrs)
		return -ENOMEM;

	temp_attr = mod->modinfo_attrs;
1578 1579
	for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
		if (!attr->test ||
1580 1581
		    (attr->test && attr->test(mod))) {
			memcpy(temp_attr, attr, sizeof(*temp_attr));
1582
			sysfs_attr_init(&temp_attr->attr);
1583 1584 1585
			error = sysfs_create_file(&mod->mkobj.kobj,&temp_attr->attr);
			++temp_attr;
		}
1586 1587 1588 1589
	}
	return error;
}

1590
static void module_remove_modinfo_attrs(struct module *mod)
1591 1592 1593 1594
{
	struct module_attribute *attr;
	int i;

1595 1596 1597 1598
	for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
		/* pick a field to test for end of list */
		if (!attr->attr.name)
			break;
1599
		sysfs_remove_file(&mod->mkobj.kobj,&attr->attr);
1600 1601
		if (attr->free)
			attr->free(mod);
1602
	}
1603
	kfree(mod->modinfo_attrs);
1604
}
L
Linus Torvalds 已提交
1605

1606
static int mod_sysfs_init(struct module *mod)
L
Linus Torvalds 已提交
1607 1608
{
	int err;
1609
	struct kobject *kobj;
L
Linus Torvalds 已提交
1610

1611 1612
	if (!module_sysfs_initialized) {
		printk(KERN_ERR "%s: module sysfs not initialized\n",
1613 1614 1615 1616
		       mod->name);
		err = -EINVAL;
		goto out;
	}
1617 1618 1619 1620 1621 1622 1623 1624 1625

	kobj = kset_find_obj(module_kset, mod->name);
	if (kobj) {
		printk(KERN_ERR "%s: module is already loaded\n", mod->name);
		kobject_put(kobj);
		err = -EINVAL;
		goto out;
	}

L
Linus Torvalds 已提交
1626
	mod->mkobj.mod = mod;
1627

1628 1629 1630 1631 1632 1633
	memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
	mod->mkobj.kobj.kset = module_kset;
	err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
				   "%s", mod->name);
	if (err)
		kobject_put(&mod->mkobj.kobj);
K
Kay Sievers 已提交
1634

1635
	/* delay uevent until full sysfs population */
K
Kay Sievers 已提交
1636 1637 1638 1639
out:
	return err;
}

1640
static int mod_sysfs_setup(struct module *mod,
R
Rusty Russell 已提交
1641
			   const struct load_info *info,
K
Kay Sievers 已提交
1642 1643 1644 1645 1646
			   struct kernel_param *kparam,
			   unsigned int num_params)
{
	int err;

1647 1648 1649 1650
	err = mod_sysfs_init(mod);
	if (err)
		goto out;

1651
	mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1652 1653
	if (!mod->holders_dir) {
		err = -ENOMEM;
K
Kay Sievers 已提交
1654
		goto out_unreg;
1655
	}
K
Kay Sievers 已提交
1656

L
Linus Torvalds 已提交
1657 1658
	err = module_param_sysfs_setup(mod, kparam, num_params);
	if (err)
K
Kay Sievers 已提交
1659
		goto out_unreg_holders;
L
Linus Torvalds 已提交
1660

1661 1662
	err = module_add_modinfo_attrs(mod);
	if (err)
1663
		goto out_unreg_param;
1664

1665
	add_usage_links(mod);
R
Rusty Russell 已提交
1666 1667
	add_sect_attrs(mod, info);
	add_notes_attrs(mod, info);
1668

1669
	kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
L
Linus Torvalds 已提交
1670 1671
	return 0;

1672 1673
out_unreg_param:
	module_param_sysfs_remove(mod);
K
Kay Sievers 已提交
1674
out_unreg_holders:
1675
	kobject_put(mod->holders_dir);
K
Kay Sievers 已提交
1676
out_unreg:
1677
	kobject_put(&mod->mkobj.kobj);
1678
out:
L
Linus Torvalds 已提交
1679 1680
	return err;
}
1681 1682 1683

static void mod_sysfs_fini(struct module *mod)
{
R
Rusty Russell 已提交
1684 1685
	remove_notes_attrs(mod);
	remove_sect_attrs(mod);
1686 1687 1688
	kobject_put(&mod->mkobj.kobj);
}

R
Rusty Russell 已提交
1689
#else /* !CONFIG_SYSFS */
1690

R
Rusty Russell 已提交
1691 1692
static int mod_sysfs_setup(struct module *mod,
			   const struct load_info *info,
1693 1694 1695 1696 1697 1698
			   struct kernel_param *kparam,
			   unsigned int num_params)
{
	return 0;
}

1699 1700 1701 1702
static void mod_sysfs_fini(struct module *mod)
{
}

1703 1704 1705 1706
static void module_remove_modinfo_attrs(struct module *mod)
{
}

1707 1708 1709 1710
static void del_usage_links(struct module *mod)
{
}

1711
#endif /* CONFIG_SYSFS */
L
Linus Torvalds 已提交
1712

1713
static void mod_sysfs_teardown(struct module *mod)
L
Linus Torvalds 已提交
1714
{
1715
	del_usage_links(mod);
1716
	module_remove_modinfo_attrs(mod);
L
Linus Torvalds 已提交
1717
	module_param_sysfs_remove(mod);
1718 1719
	kobject_put(mod->mkobj.drivers_dir);
	kobject_put(mod->holders_dir);
1720
	mod_sysfs_fini(mod);
L
Linus Torvalds 已提交
1721 1722 1723 1724 1725 1726 1727 1728 1729 1730
}

/*
 * unlink the module with the whole machine is stopped with interrupts off
 * - this defends against kallsyms not taking locks
 */
static int __unlink_module(void *_mod)
{
	struct module *mod = _mod;
	list_del(&mod->list);
1731
	module_bug_cleanup(mod);
L
Linus Torvalds 已提交
1732 1733 1734
	return 0;
}

1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766 1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777 1778
#ifdef CONFIG_DEBUG_SET_MODULE_RONX
/*
 * LKM RO/NX protection: protect module's text/ro-data
 * from modification and any data from execution.
 */
void set_page_attributes(void *start, void *end, int (*set)(unsigned long start, int num_pages))
{
	unsigned long begin_pfn = PFN_DOWN((unsigned long)start);
	unsigned long end_pfn = PFN_DOWN((unsigned long)end);

	if (end_pfn > begin_pfn)
		set(begin_pfn << PAGE_SHIFT, end_pfn - begin_pfn);
}

static void set_section_ro_nx(void *base,
			unsigned long text_size,
			unsigned long ro_size,
			unsigned long total_size)
{
	/* begin and end PFNs of the current subsection */
	unsigned long begin_pfn;
	unsigned long end_pfn;

	/*
	 * Set RO for module text and RO-data:
	 * - Always protect first page.
	 * - Do not protect last partial page.
	 */
	if (ro_size > 0)
		set_page_attributes(base, base + ro_size, set_memory_ro);

	/*
	 * Set NX permissions for module data:
	 * - Do not protect first partial page.
	 * - Always protect last page.
	 */
	if (total_size > text_size) {
		begin_pfn = PFN_UP((unsigned long)base + text_size);
		end_pfn = PFN_UP((unsigned long)base + total_size);
		if (end_pfn > begin_pfn)
			set_memory_nx(begin_pfn << PAGE_SHIFT, end_pfn - begin_pfn);
	}
}

1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789 1790 1791 1792 1793 1794 1795 1796
static void unset_module_core_ro_nx(struct module *mod)
{
	set_page_attributes(mod->module_core + mod->core_text_size,
		mod->module_core + mod->core_size,
		set_memory_x);
	set_page_attributes(mod->module_core,
		mod->module_core + mod->core_ro_size,
		set_memory_rw);
}

static void unset_module_init_ro_nx(struct module *mod)
{
	set_page_attributes(mod->module_init + mod->init_text_size,
		mod->module_init + mod->init_size,
		set_memory_x);
	set_page_attributes(mod->module_init,
		mod->module_init + mod->init_ro_size,
		set_memory_rw);
1797 1798 1799
}

/* Iterate through all modules and set each module's text as RW */
1800
void set_all_modules_text_rw(void)
1801 1802 1803 1804 1805
{
	struct module *mod;

	mutex_lock(&module_mutex);
	list_for_each_entry_rcu(mod, &modules, list) {
1806 1807
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822
		if ((mod->module_core) && (mod->core_text_size)) {
			set_page_attributes(mod->module_core,
						mod->module_core + mod->core_text_size,
						set_memory_rw);
		}
		if ((mod->module_init) && (mod->init_text_size)) {
			set_page_attributes(mod->module_init,
						mod->module_init + mod->init_text_size,
						set_memory_rw);
		}
	}
	mutex_unlock(&module_mutex);
}

/* Iterate through all modules and set each module's text as RO */
1823
void set_all_modules_text_ro(void)
1824 1825 1826 1827 1828
{
	struct module *mod;

	mutex_lock(&module_mutex);
	list_for_each_entry_rcu(mod, &modules, list) {
1829 1830
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
1831 1832 1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845
		if ((mod->module_core) && (mod->core_text_size)) {
			set_page_attributes(mod->module_core,
						mod->module_core + mod->core_text_size,
						set_memory_ro);
		}
		if ((mod->module_init) && (mod->init_text_size)) {
			set_page_attributes(mod->module_init,
						mod->module_init + mod->init_text_size,
						set_memory_ro);
		}
	}
	mutex_unlock(&module_mutex);
}
#else
static inline void set_section_ro_nx(void *base, unsigned long text_size, unsigned long ro_size, unsigned long total_size) { }
1846 1847
static void unset_module_core_ro_nx(struct module *mod) { }
static void unset_module_init_ro_nx(struct module *mod) { }
1848 1849
#endif

1850 1851 1852 1853 1854 1855 1856 1857 1858
void __weak module_free(struct module *mod, void *module_region)
{
	vfree(module_region);
}

void __weak module_arch_cleanup(struct module *mod)
{
}

1859
/* Free a module, remove from lists, etc. */
L
Linus Torvalds 已提交
1860 1861
static void free_module(struct module *mod)
{
1862 1863
	trace_module_free(mod);

L
Linus Torvalds 已提交
1864
	/* Delete from various lists */
1865
	mutex_lock(&module_mutex);
1866
	stop_machine(__unlink_module, mod, NULL);
1867
	mutex_unlock(&module_mutex);
1868
	mod_sysfs_teardown(mod);
L
Linus Torvalds 已提交
1869

1870 1871 1872
	/* Remove dynamic debug info */
	ddebug_remove_module(mod->name);

L
Linus Torvalds 已提交
1873 1874 1875 1876 1877 1878
	/* Arch-specific cleanup. */
	module_arch_cleanup(mod);

	/* Module unload stuff */
	module_unload_free(mod);

1879 1880 1881
	/* Free any allocated parameters. */
	destroy_params(mod->kp, mod->num_kp);

L
Linus Torvalds 已提交
1882
	/* This may be NULL, but that's OK */
1883
	unset_module_init_ro_nx(mod);
L
Linus Torvalds 已提交
1884 1885
	module_free(mod, mod->module_init);
	kfree(mod->args);
1886
	percpu_modfree(mod);
1887

I
Ingo Molnar 已提交
1888 1889 1890
	/* Free lock-classes: */
	lockdep_free_key_range(mod->module_core, mod->core_size);

L
Linus Torvalds 已提交
1891
	/* Finally, free the core (containing the module structure) */
1892
	unset_module_core_ro_nx(mod);
L
Linus Torvalds 已提交
1893
	module_free(mod, mod->module_core);
1894 1895 1896 1897

#ifdef CONFIG_MPU
	update_protections(current->mm);
#endif
L
Linus Torvalds 已提交
1898 1899 1900 1901 1902
}

void *__symbol_get(const char *symbol)
{
	struct module *owner;
1903
	const struct kernel_symbol *sym;
L
Linus Torvalds 已提交
1904

1905
	preempt_disable();
1906 1907 1908
	sym = find_symbol(symbol, &owner, NULL, true, true);
	if (sym && strong_try_module_get(owner))
		sym = NULL;
1909
	preempt_enable();
L
Linus Torvalds 已提交
1910

1911
	return sym ? (void *)sym->value : NULL;
L
Linus Torvalds 已提交
1912 1913 1914
}
EXPORT_SYMBOL_GPL(__symbol_get);

1915 1916
/*
 * Ensure that an exported symbol [global namespace] does not already exist
1917
 * in the kernel or in some other module's exported symbol table.
1918 1919
 *
 * You must hold the module_mutex.
1920 1921 1922
 */
static int verify_export_symbols(struct module *mod)
{
1923
	unsigned int i;
1924
	struct module *owner;
1925 1926 1927 1928 1929 1930 1931 1932
	const struct kernel_symbol *s;
	struct {
		const struct kernel_symbol *sym;
		unsigned int num;
	} arr[] = {
		{ mod->syms, mod->num_syms },
		{ mod->gpl_syms, mod->num_gpl_syms },
		{ mod->gpl_future_syms, mod->num_gpl_future_syms },
1933
#ifdef CONFIG_UNUSED_SYMBOLS
1934 1935
		{ mod->unused_syms, mod->num_unused_syms },
		{ mod->unused_gpl_syms, mod->num_unused_gpl_syms },
1936
#endif
1937
	};
1938

1939 1940
	for (i = 0; i < ARRAY_SIZE(arr); i++) {
		for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
1941
			if (find_symbol(s->name, &owner, NULL, true, false)) {
1942 1943 1944 1945 1946 1947
				printk(KERN_ERR
				       "%s: exports duplicate symbol %s"
				       " (owned by %s)\n",
				       mod->name, s->name, module_name(owner));
				return -ENOEXEC;
			}
1948
		}
1949 1950
	}
	return 0;
1951 1952
}

1953
/* Change all symbols so that st_value encodes the pointer directly. */
1954 1955 1956 1957
static int simplify_symbols(struct module *mod, const struct load_info *info)
{
	Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
	Elf_Sym *sym = (void *)symsec->sh_addr;
L
Linus Torvalds 已提交
1958
	unsigned long secbase;
1959
	unsigned int i;
L
Linus Torvalds 已提交
1960
	int ret = 0;
1961
	const struct kernel_symbol *ksym;
L
Linus Torvalds 已提交
1962

1963 1964 1965
	for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
		const char *name = info->strtab + sym[i].st_name;

L
Linus Torvalds 已提交
1966 1967 1968 1969
		switch (sym[i].st_shndx) {
		case SHN_COMMON:
			/* We compiled with -fno-common.  These are not
			   supposed to happen.  */
1970
			pr_debug("Common symbol: %s\n", name);
L
Linus Torvalds 已提交
1971 1972 1973 1974 1975 1976 1977
			printk("%s: please compile with -fno-common\n",
			       mod->name);
			ret = -ENOEXEC;
			break;

		case SHN_ABS:
			/* Don't need to do anything */
1978
			pr_debug("Absolute symbol: 0x%08lx\n",
L
Linus Torvalds 已提交
1979 1980 1981 1982
			       (long)sym[i].st_value);
			break;

		case SHN_UNDEF:
1983
			ksym = resolve_symbol_wait(mod, info, name);
L
Linus Torvalds 已提交
1984
			/* Ok if resolved.  */
1985
			if (ksym && !IS_ERR(ksym)) {
1986
				sym[i].st_value = ksym->value;
L
Linus Torvalds 已提交
1987
				break;
1988 1989
			}

L
Linus Torvalds 已提交
1990
			/* Ok if weak.  */
1991
			if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
L
Linus Torvalds 已提交
1992 1993
				break;

1994
			printk(KERN_WARNING "%s: Unknown symbol %s (err %li)\n",
1995
			       mod->name, name, PTR_ERR(ksym));
1996
			ret = PTR_ERR(ksym) ?: -ENOENT;
L
Linus Torvalds 已提交
1997 1998 1999 2000
			break;

		default:
			/* Divert to percpu allocation if a percpu var. */
2001
			if (sym[i].st_shndx == info->index.pcpu)
2002
				secbase = (unsigned long)mod_percpu(mod);
L
Linus Torvalds 已提交
2003
			else
2004
				secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
L
Linus Torvalds 已提交
2005 2006 2007 2008 2009 2010 2011 2012
			sym[i].st_value += secbase;
			break;
		}
	}

	return ret;
}

2013
static int apply_relocations(struct module *mod, const struct load_info *info)
2014 2015 2016 2017 2018
{
	unsigned int i;
	int err = 0;

	/* Now do relocations. */
2019 2020
	for (i = 1; i < info->hdr->e_shnum; i++) {
		unsigned int infosec = info->sechdrs[i].sh_info;
2021 2022

		/* Not a valid relocation section? */
2023
		if (infosec >= info->hdr->e_shnum)
2024 2025 2026
			continue;

		/* Don't bother with non-allocated sections */
2027
		if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
2028 2029
			continue;

2030 2031 2032 2033 2034 2035
		if (info->sechdrs[i].sh_type == SHT_REL)
			err = apply_relocate(info->sechdrs, info->strtab,
					     info->index.sym, i, mod);
		else if (info->sechdrs[i].sh_type == SHT_RELA)
			err = apply_relocate_add(info->sechdrs, info->strtab,
						 info->index.sym, i, mod);
2036 2037 2038 2039 2040 2041
		if (err < 0)
			break;
	}
	return err;
}

2042 2043 2044 2045 2046 2047 2048 2049
/* Additional bytes needed by arch in front of individual sections */
unsigned int __weak arch_mod_section_prepend(struct module *mod,
					     unsigned int section)
{
	/* default implementation just returns zero */
	return 0;
}

L
Linus Torvalds 已提交
2050
/* Update size with this section: return offset. */
2051 2052
static long get_offset(struct module *mod, unsigned int *size,
		       Elf_Shdr *sechdr, unsigned int section)
L
Linus Torvalds 已提交
2053 2054 2055
{
	long ret;

2056
	*size += arch_mod_section_prepend(mod, section);
L
Linus Torvalds 已提交
2057 2058 2059 2060 2061 2062 2063 2064 2065
	ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
	*size = ret + sechdr->sh_size;
	return ret;
}

/* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
   might -- code, read-only data, read-write data, small data.  Tally
   sizes, and place the offsets into sh_entsize fields: high bit means it
   belongs in init. */
2066
static void layout_sections(struct module *mod, struct load_info *info)
L
Linus Torvalds 已提交
2067 2068 2069 2070 2071 2072 2073 2074 2075 2076 2077 2078
{
	static unsigned long const masks[][2] = {
		/* NOTE: all executable code must be the first section
		 * in this array; otherwise modify the text_size
		 * finder in the two loops below */
		{ SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
		{ SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
		{ SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
		{ ARCH_SHF_SMALL | SHF_ALLOC, 0 }
	};
	unsigned int m, i;

2079 2080
	for (i = 0; i < info->hdr->e_shnum; i++)
		info->sechdrs[i].sh_entsize = ~0UL;
L
Linus Torvalds 已提交
2081

2082
	pr_debug("Core section allocation order:\n");
L
Linus Torvalds 已提交
2083
	for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2084 2085 2086
		for (i = 0; i < info->hdr->e_shnum; ++i) {
			Elf_Shdr *s = &info->sechdrs[i];
			const char *sname = info->secstrings + s->sh_name;
L
Linus Torvalds 已提交
2087 2088 2089 2090

			if ((s->sh_flags & masks[m][0]) != masks[m][0]
			    || (s->sh_flags & masks[m][1])
			    || s->sh_entsize != ~0UL
2091
			    || strstarts(sname, ".init"))
L
Linus Torvalds 已提交
2092
				continue;
2093
			s->sh_entsize = get_offset(mod, &mod->core_size, s, i);
2094
			pr_debug("\t%s\n", sname);
L
Linus Torvalds 已提交
2095
		}
2096 2097 2098
		switch (m) {
		case 0: /* executable */
			mod->core_size = debug_align(mod->core_size);
L
Linus Torvalds 已提交
2099
			mod->core_text_size = mod->core_size;
2100 2101 2102 2103 2104 2105 2106 2107 2108
			break;
		case 1: /* RO: text and ro-data */
			mod->core_size = debug_align(mod->core_size);
			mod->core_ro_size = mod->core_size;
			break;
		case 3: /* whole core */
			mod->core_size = debug_align(mod->core_size);
			break;
		}
L
Linus Torvalds 已提交
2109 2110
	}

2111
	pr_debug("Init section allocation order:\n");
L
Linus Torvalds 已提交
2112
	for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2113 2114 2115
		for (i = 0; i < info->hdr->e_shnum; ++i) {
			Elf_Shdr *s = &info->sechdrs[i];
			const char *sname = info->secstrings + s->sh_name;
L
Linus Torvalds 已提交
2116 2117 2118 2119

			if ((s->sh_flags & masks[m][0]) != masks[m][0]
			    || (s->sh_flags & masks[m][1])
			    || s->sh_entsize != ~0UL
2120
			    || !strstarts(sname, ".init"))
L
Linus Torvalds 已提交
2121
				continue;
2122
			s->sh_entsize = (get_offset(mod, &mod->init_size, s, i)
L
Linus Torvalds 已提交
2123
					 | INIT_OFFSET_MASK);
2124
			pr_debug("\t%s\n", sname);
L
Linus Torvalds 已提交
2125
		}
2126 2127 2128
		switch (m) {
		case 0: /* executable */
			mod->init_size = debug_align(mod->init_size);
L
Linus Torvalds 已提交
2129
			mod->init_text_size = mod->init_size;
2130 2131 2132 2133 2134 2135 2136 2137 2138
			break;
		case 1: /* RO: text and ro-data */
			mod->init_size = debug_align(mod->init_size);
			mod->init_ro_size = mod->init_size;
			break;
		case 3: /* whole init */
			mod->init_size = debug_align(mod->init_size);
			break;
		}
L
Linus Torvalds 已提交
2139 2140 2141 2142 2143 2144 2145 2146
	}
}

static void set_license(struct module *mod, const char *license)
{
	if (!license)
		license = "unspecified";

2147
	if (!license_is_gpl_compatible(license)) {
2148
		if (!test_taint(TAINT_PROPRIETARY_MODULE))
2149
			printk(KERN_WARNING "%s: module license '%s' taints "
2150
				"kernel.\n", mod->name, license);
2151 2152
		add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
				 LOCKDEP_NOW_UNRELIABLE);
L
Linus Torvalds 已提交
2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 2172 2173 2174
	}
}

/* Parse tag=value strings from .modinfo section */
static char *next_string(char *string, unsigned long *secsize)
{
	/* Skip non-zero chars */
	while (string[0]) {
		string++;
		if ((*secsize)-- <= 1)
			return NULL;
	}

	/* Skip any zero padding. */
	while (!string[0]) {
		string++;
		if ((*secsize)-- <= 1)
			return NULL;
	}
	return string;
}

2175
static char *get_modinfo(struct load_info *info, const char *tag)
L
Linus Torvalds 已提交
2176 2177 2178
{
	char *p;
	unsigned int taglen = strlen(tag);
2179 2180
	Elf_Shdr *infosec = &info->sechdrs[info->index.info];
	unsigned long size = infosec->sh_size;
L
Linus Torvalds 已提交
2181

2182
	for (p = (char *)infosec->sh_addr; p; p = next_string(p, &size)) {
L
Linus Torvalds 已提交
2183 2184 2185 2186 2187 2188
		if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
			return p + taglen + 1;
	}
	return NULL;
}

2189
static void setup_modinfo(struct module *mod, struct load_info *info)
2190 2191 2192 2193 2194 2195
{
	struct module_attribute *attr;
	int i;

	for (i = 0; (attr = modinfo_attrs[i]); i++) {
		if (attr->setup)
2196
			attr->setup(mod, get_modinfo(info, attr->attr.name));
2197 2198 2199
	}
}

2200 2201 2202 2203 2204 2205 2206 2207 2208 2209 2210
static void free_modinfo(struct module *mod)
{
	struct module_attribute *attr;
	int i;

	for (i = 0; (attr = modinfo_attrs[i]); i++) {
		if (attr->free)
			attr->free(mod);
	}
}

L
Linus Torvalds 已提交
2211
#ifdef CONFIG_KALLSYMS
2212 2213 2214 2215 2216 2217

/* lookup symbol in given range of kernel_symbols */
static const struct kernel_symbol *lookup_symbol(const char *name,
	const struct kernel_symbol *start,
	const struct kernel_symbol *stop)
{
2218 2219
	return bsearch(name, start, stop - start,
			sizeof(struct kernel_symbol), cmp_name);
2220 2221
}

2222 2223
static int is_exported(const char *name, unsigned long value,
		       const struct module *mod)
L
Linus Torvalds 已提交
2224
{
2225 2226 2227
	const struct kernel_symbol *ks;
	if (!mod)
		ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
2228
	else
2229 2230
		ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
	return ks != NULL && ks->value == value;
L
Linus Torvalds 已提交
2231 2232 2233
}

/* As per nm */
2234
static char elf_type(const Elf_Sym *sym, const struct load_info *info)
L
Linus Torvalds 已提交
2235
{
2236 2237
	const Elf_Shdr *sechdrs = info->sechdrs;

L
Linus Torvalds 已提交
2238 2239 2240 2241 2242 2243 2244 2245 2246 2247 2248 2249 2250 2251 2252 2253 2254 2255 2256 2257 2258 2259 2260 2261 2262 2263 2264 2265 2266
	if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
		if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
			return 'v';
		else
			return 'w';
	}
	if (sym->st_shndx == SHN_UNDEF)
		return 'U';
	if (sym->st_shndx == SHN_ABS)
		return 'a';
	if (sym->st_shndx >= SHN_LORESERVE)
		return '?';
	if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
		return 't';
	if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
	    && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
		if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
			return 'r';
		else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
			return 'g';
		else
			return 'd';
	}
	if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
		if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
			return 's';
		else
			return 'b';
	}
2267 2268
	if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
		      ".debug")) {
L
Linus Torvalds 已提交
2269
		return 'n';
2270
	}
L
Linus Torvalds 已提交
2271 2272 2273
	return '?';
}

2274 2275 2276 2277 2278 2279 2280 2281 2282 2283 2284 2285 2286 2287 2288 2289 2290 2291 2292 2293 2294
static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
                           unsigned int shnum)
{
	const Elf_Shdr *sec;

	if (src->st_shndx == SHN_UNDEF
	    || src->st_shndx >= shnum
	    || !src->st_name)
		return false;

	sec = sechdrs + src->st_shndx;
	if (!(sec->sh_flags & SHF_ALLOC)
#ifndef CONFIG_KALLSYMS_ALL
	    || !(sec->sh_flags & SHF_EXECINSTR)
#endif
	    || (sec->sh_entsize & INIT_OFFSET_MASK))
		return false;

	return true;
}

2295 2296 2297 2298 2299 2300 2301
/*
 * We only allocate and copy the strings needed by the parts of symtab
 * we keep.  This is simple, but has the effect of making multiple
 * copies of duplicates.  We could be more sophisticated, see
 * linux-kernel thread starting with
 * <73defb5e4bca04a6431392cc341112b1@localhost>.
 */
2302
static void layout_symtab(struct module *mod, struct load_info *info)
2303
{
2304 2305
	Elf_Shdr *symsect = info->sechdrs + info->index.sym;
	Elf_Shdr *strsect = info->sechdrs + info->index.str;
2306
	const Elf_Sym *src;
2307
	unsigned int i, nsrc, ndst, strtab_size = 0;
2308 2309 2310 2311

	/* Put symbol section at end of init part of module. */
	symsect->sh_flags |= SHF_ALLOC;
	symsect->sh_entsize = get_offset(mod, &mod->init_size, symsect,
2312
					 info->index.sym) | INIT_OFFSET_MASK;
2313
	pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
2314

2315
	src = (void *)info->hdr + symsect->sh_offset;
2316
	nsrc = symsect->sh_size / sizeof(*src);
2317

2318
	/* Compute total space required for the core symbols' strtab. */
2319 2320 2321 2322
	for (ndst = i = 0; i < nsrc; i++) {
		if (i == 0 ||
		    is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum)) {
			strtab_size += strlen(&info->strtab[src[i].st_name])+1;
2323
			ndst++;
2324
		}
2325
	}
2326 2327

	/* Append room for core symbols at end of core part. */
2328
	info->symoffs = ALIGN(mod->core_size, symsect->sh_addralign ?: 1);
2329 2330
	info->stroffs = mod->core_size = info->symoffs + ndst * sizeof(Elf_Sym);
	mod->core_size += strtab_size;
2331

2332 2333 2334
	/* Put string table section at end of init part of module. */
	strsect->sh_flags |= SHF_ALLOC;
	strsect->sh_entsize = get_offset(mod, &mod->init_size, strsect,
2335
					 info->index.str) | INIT_OFFSET_MASK;
2336
	pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
2337 2338
}

2339
static void add_kallsyms(struct module *mod, const struct load_info *info)
L
Linus Torvalds 已提交
2340
{
2341 2342 2343
	unsigned int i, ndst;
	const Elf_Sym *src;
	Elf_Sym *dst;
2344
	char *s;
2345
	Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
L
Linus Torvalds 已提交
2346

2347 2348
	mod->symtab = (void *)symsec->sh_addr;
	mod->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
2349 2350
	/* Make sure we get permanent strtab: don't use info->strtab. */
	mod->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
L
Linus Torvalds 已提交
2351 2352 2353

	/* Set types up while we still have access to sections. */
	for (i = 0; i < mod->num_symtab; i++)
2354
		mod->symtab[i].st_info = elf_type(&mod->symtab[i], info);
2355

2356
	mod->core_symtab = dst = mod->module_core + info->symoffs;
2357
	mod->core_strtab = s = mod->module_core + info->stroffs;
2358
	src = mod->symtab;
2359 2360 2361 2362 2363 2364 2365 2366
	for (ndst = i = 0; i < mod->num_symtab; i++) {
		if (i == 0 ||
		    is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum)) {
			dst[ndst] = src[i];
			dst[ndst++].st_name = s - mod->core_strtab;
			s += strlcpy(s, &mod->strtab[src[i].st_name],
				     KSYM_NAME_LEN) + 1;
		}
2367 2368
	}
	mod->core_num_syms = ndst;
L
Linus Torvalds 已提交
2369 2370
}
#else
2371
static inline void layout_symtab(struct module *mod, struct load_info *info)
2372 2373
{
}
2374

2375
static void add_kallsyms(struct module *mod, const struct load_info *info)
L
Linus Torvalds 已提交
2376 2377 2378 2379
{
}
#endif /* CONFIG_KALLSYMS */

2380
static void dynamic_debug_setup(struct _ddebug *debug, unsigned int num)
2381
{
2382 2383
	if (!debug)
		return;
2384 2385 2386 2387 2388
#ifdef CONFIG_DYNAMIC_DEBUG
	if (ddebug_add_module(debug, num, debug->modname))
		printk(KERN_ERR "dynamic debug error adding module: %s\n",
					debug->modname);
#endif
2389
}
2390

2391 2392 2393 2394 2395 2396
static void dynamic_debug_remove(struct _ddebug *debug)
{
	if (debug)
		ddebug_remove_module(debug->modname);
}

2397 2398
void * __weak module_alloc(unsigned long size)
{
2399
	return vmalloc_exec(size);
2400 2401
}

2402 2403 2404 2405 2406
static void *module_alloc_update_bounds(unsigned long size)
{
	void *ret = module_alloc(size);

	if (ret) {
2407
		mutex_lock(&module_mutex);
2408 2409 2410 2411 2412
		/* Update module bounds. */
		if ((unsigned long)ret < module_addr_min)
			module_addr_min = (unsigned long)ret;
		if ((unsigned long)ret + size > module_addr_max)
			module_addr_max = (unsigned long)ret + size;
2413
		mutex_unlock(&module_mutex);
2414 2415 2416 2417
	}
	return ret;
}

2418
#ifdef CONFIG_DEBUG_KMEMLEAK
2419 2420
static void kmemleak_load_module(const struct module *mod,
				 const struct load_info *info)
2421 2422 2423 2424
{
	unsigned int i;

	/* only scan the sections containing data */
2425
	kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
2426

2427 2428 2429
	for (i = 1; i < info->hdr->e_shnum; i++) {
		const char *name = info->secstrings + info->sechdrs[i].sh_name;
		if (!(info->sechdrs[i].sh_flags & SHF_ALLOC))
2430
			continue;
2431
		if (!strstarts(name, ".data") && !strstarts(name, ".bss"))
2432 2433
			continue;

2434 2435
		kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
				   info->sechdrs[i].sh_size, GFP_KERNEL);
2436 2437 2438
	}
}
#else
2439 2440
static inline void kmemleak_load_module(const struct module *mod,
					const struct load_info *info)
2441 2442 2443 2444
{
}
#endif

2445
#ifdef CONFIG_MODULE_SIG
2446
static int module_sig_check(struct load_info *info)
2447 2448
{
	int err = -ENOKEY;
2449 2450
	const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
	const void *mod = info->hdr;
2451

2452 2453
	if (info->len > markerlen &&
	    memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
2454
		/* We truncate the module to discard the signature */
2455 2456
		info->len -= markerlen;
		err = mod_verify_sig(mod, &info->len);
2457 2458 2459 2460 2461 2462 2463 2464
	}

	if (!err) {
		info->sig_ok = true;
		return 0;
	}

	/* Not having a signature is only an error if we're strict. */
D
David Howells 已提交
2465 2466 2467
	if (err < 0 && fips_enabled)
		panic("Module verification failed with error %d in FIPS mode\n",
		      err);
2468 2469 2470 2471 2472 2473
	if (err == -ENOKEY && !sig_enforce)
		err = 0;

	return err;
}
#else /* !CONFIG_MODULE_SIG */
2474
static int module_sig_check(struct load_info *info)
2475 2476 2477 2478 2479
{
	return 0;
}
#endif /* !CONFIG_MODULE_SIG */

2480 2481
/* Sanity checks against invalid binaries, wrong arch, weird elf version. */
static int elf_header_check(struct load_info *info)
2482
{
2483 2484 2485 2486 2487 2488 2489 2490 2491 2492 2493 2494 2495
	if (info->len < sizeof(*(info->hdr)))
		return -ENOEXEC;

	if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0
	    || info->hdr->e_type != ET_REL
	    || !elf_check_arch(info->hdr)
	    || info->hdr->e_shentsize != sizeof(Elf_Shdr))
		return -ENOEXEC;

	if (info->hdr->e_shoff >= info->len
	    || (info->hdr->e_shnum * sizeof(Elf_Shdr) >
		info->len - info->hdr->e_shoff))
		return -ENOEXEC;
2496

2497 2498 2499 2500 2501 2502
	return 0;
}

/* Sets info->hdr and info->len. */
static int copy_module_from_user(const void __user *umod, unsigned long len,
				  struct load_info *info)
2503 2504 2505
{
	int err;

2506 2507
	info->len = len;
	if (info->len < sizeof(*(info->hdr)))
2508 2509
		return -ENOEXEC;

2510 2511 2512 2513
	err = security_kernel_module_from_file(NULL);
	if (err)
		return err;

2514
	/* Suck in entire file: we'll want most of it. */
2515 2516
	info->hdr = vmalloc(info->len);
	if (!info->hdr)
2517 2518
		return -ENOMEM;

2519 2520 2521
	if (copy_from_user(info->hdr, umod, info->len) != 0) {
		vfree(info->hdr);
		return -EFAULT;
2522 2523
	}

2524 2525 2526 2527 2528 2529 2530 2531 2532 2533 2534 2535 2536 2537 2538 2539
	return 0;
}

/* Sets info->hdr and info->len. */
static int copy_module_from_fd(int fd, struct load_info *info)
{
	struct file *file;
	int err;
	struct kstat stat;
	loff_t pos;
	ssize_t bytes = 0;

	file = fget(fd);
	if (!file)
		return -ENOEXEC;

2540
	err = security_kernel_module_from_file(file);
2541
	if (err)
2542
		goto out;
2543

2544
	err = vfs_getattr(&file->f_path, &stat);
2545
	if (err)
2546
		goto out;
2547

2548 2549 2550
	if (stat.size > INT_MAX) {
		err = -EFBIG;
		goto out;
2551
	}
2552 2553 2554 2555 2556 2557 2558

	/* Don't hand 0 to vmalloc, it whines. */
	if (stat.size == 0) {
		err = -EINVAL;
		goto out;
	}

2559 2560 2561 2562
	info->hdr = vmalloc(stat.size);
	if (!info->hdr) {
		err = -ENOMEM;
		goto out;
2563
	}
2564

2565 2566 2567 2568 2569 2570 2571 2572 2573 2574 2575 2576 2577 2578
	pos = 0;
	while (pos < stat.size) {
		bytes = kernel_read(file, pos, (char *)(info->hdr) + pos,
				    stat.size - pos);
		if (bytes < 0) {
			vfree(info->hdr);
			err = bytes;
			goto out;
		}
		if (bytes == 0)
			break;
		pos += bytes;
	}
	info->len = pos;
2579

2580 2581
out:
	fput(file);
2582 2583 2584
	return err;
}

2585 2586 2587 2588 2589
static void free_copy(struct load_info *info)
{
	vfree(info->hdr);
}

2590
static int rewrite_section_headers(struct load_info *info, int flags)
2591 2592 2593 2594 2595 2596 2597 2598 2599 2600 2601 2602 2603 2604 2605 2606 2607 2608 2609 2610 2611 2612 2613 2614 2615
{
	unsigned int i;

	/* This should always be true, but let's be sure. */
	info->sechdrs[0].sh_addr = 0;

	for (i = 1; i < info->hdr->e_shnum; i++) {
		Elf_Shdr *shdr = &info->sechdrs[i];
		if (shdr->sh_type != SHT_NOBITS
		    && info->len < shdr->sh_offset + shdr->sh_size) {
			printk(KERN_ERR "Module len %lu truncated\n",
			       info->len);
			return -ENOEXEC;
		}

		/* Mark all sections sh_addr with their address in the
		   temporary image. */
		shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;

#ifndef CONFIG_MODULE_UNLOAD
		/* Don't load .exit sections */
		if (strstarts(info->secstrings+shdr->sh_name, ".exit"))
			shdr->sh_flags &= ~(unsigned long)SHF_ALLOC;
#endif
	}
2616 2617

	/* Track but don't keep modinfo and version sections. */
2618 2619 2620 2621
	if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
		info->index.vers = 0; /* Pretend no __versions section! */
	else
		info->index.vers = find_sec(info, "__versions");
2622
	info->index.info = find_sec(info, ".modinfo");
2623 2624
	info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
	info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
2625 2626 2627
	return 0;
}

L
Linus Torvalds 已提交
2628 2629 2630 2631 2632 2633 2634 2635
/*
 * Set up our basic convenience variables (pointers to section headers,
 * search for module section index etc), and do some basic section
 * verification.
 *
 * Return the temporary module pointer (we'll replace it with the final
 * one when we move the module sections around).
 */
2636
static struct module *setup_load_info(struct load_info *info, int flags)
L
Linus Torvalds 已提交
2637 2638
{
	unsigned int i;
2639
	int err;
L
Linus Torvalds 已提交
2640 2641 2642 2643
	struct module *mod;

	/* Set up the convenience variables */
	info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
2644 2645
	info->secstrings = (void *)info->hdr
		+ info->sechdrs[info->hdr->e_shstrndx].sh_offset;
L
Linus Torvalds 已提交
2646

2647
	err = rewrite_section_headers(info, flags);
2648 2649
	if (err)
		return ERR_PTR(err);
L
Linus Torvalds 已提交
2650

2651 2652
	/* Find internal symbols and strings. */
	for (i = 1; i < info->hdr->e_shnum; i++) {
L
Linus Torvalds 已提交
2653 2654 2655
		if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
			info->index.sym = i;
			info->index.str = info->sechdrs[i].sh_link;
2656 2657 2658
			info->strtab = (char *)info->hdr
				+ info->sechdrs[info->index.str].sh_offset;
			break;
L
Linus Torvalds 已提交
2659 2660 2661
		}
	}

2662
	info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
L
Linus Torvalds 已提交
2663 2664 2665 2666 2667 2668 2669 2670 2671 2672 2673 2674 2675
	if (!info->index.mod) {
		printk(KERN_WARNING "No module found in object\n");
		return ERR_PTR(-ENOEXEC);
	}
	/* This is temporary: point mod into copy of data. */
	mod = (void *)info->sechdrs[info->index.mod].sh_addr;

	if (info->index.sym == 0) {
		printk(KERN_WARNING "%s: module has no symbols (stripped?)\n",
		       mod->name);
		return ERR_PTR(-ENOEXEC);
	}

2676
	info->index.pcpu = find_pcpusec(info);
L
Linus Torvalds 已提交
2677 2678 2679 2680 2681 2682 2683 2684

	/* Check module struct version now, before we try to use module. */
	if (!check_modstruct_version(info->sechdrs, info->index.vers, mod))
		return ERR_PTR(-ENOEXEC);

	return mod;
}

2685
static int check_modinfo(struct module *mod, struct load_info *info, int flags)
2686
{
2687
	const char *modmagic = get_modinfo(info, "vermagic");
2688 2689
	int err;

2690 2691 2692
	if (flags & MODULE_INIT_IGNORE_VERMAGIC)
		modmagic = NULL;

2693 2694 2695 2696 2697
	/* This is allowed: modprobe --force will invalidate it. */
	if (!modmagic) {
		err = try_to_force_load(mod, "bad vermagic");
		if (err)
			return err;
2698
	} else if (!same_magic(modmagic, vermagic, info->index.vers)) {
2699 2700 2701 2702 2703
		printk(KERN_ERR "%s: version magic '%s' should be '%s'\n",
		       mod->name, modmagic, vermagic);
		return -ENOEXEC;
	}

2704
	if (!get_modinfo(info, "intree"))
2705
		add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
2706

2707
	if (get_modinfo(info, "staging")) {
2708
		add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
2709 2710 2711 2712
		printk(KERN_WARNING "%s: module is from the staging directory,"
		       " the quality is unknown, you have been warned.\n",
		       mod->name);
	}
2713 2714

	/* Set up license info based on the info section */
2715
	set_license(mod, get_modinfo(info, "license"));
2716

2717 2718 2719
	return 0;
}

2720
static void find_module_sections(struct module *mod, struct load_info *info)
2721
{
2722
	mod->kp = section_objs(info, "__param",
2723
			       sizeof(*mod->kp), &mod->num_kp);
2724
	mod->syms = section_objs(info, "__ksymtab",
2725
				 sizeof(*mod->syms), &mod->num_syms);
2726 2727
	mod->crcs = section_addr(info, "__kcrctab");
	mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
2728 2729
				     sizeof(*mod->gpl_syms),
				     &mod->num_gpl_syms);
2730 2731
	mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
	mod->gpl_future_syms = section_objs(info,
2732 2733 2734
					    "__ksymtab_gpl_future",
					    sizeof(*mod->gpl_future_syms),
					    &mod->num_gpl_future_syms);
2735
	mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future");
2736 2737

#ifdef CONFIG_UNUSED_SYMBOLS
2738
	mod->unused_syms = section_objs(info, "__ksymtab_unused",
2739 2740
					sizeof(*mod->unused_syms),
					&mod->num_unused_syms);
2741 2742
	mod->unused_crcs = section_addr(info, "__kcrctab_unused");
	mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl",
2743 2744
					    sizeof(*mod->unused_gpl_syms),
					    &mod->num_unused_gpl_syms);
2745
	mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl");
2746 2747
#endif
#ifdef CONFIG_CONSTRUCTORS
2748
	mod->ctors = section_objs(info, ".ctors",
2749 2750 2751 2752
				  sizeof(*mod->ctors), &mod->num_ctors);
#endif

#ifdef CONFIG_TRACEPOINTS
2753 2754 2755
	mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
					     sizeof(*mod->tracepoints_ptrs),
					     &mod->num_tracepoints);
2756
#endif
2757 2758 2759 2760 2761
#ifdef HAVE_JUMP_LABEL
	mod->jump_entries = section_objs(info, "__jump_table",
					sizeof(*mod->jump_entries),
					&mod->num_jump_entries);
#endif
2762
#ifdef CONFIG_EVENT_TRACING
2763
	mod->trace_events = section_objs(info, "_ftrace_events",
2764 2765 2766 2767 2768 2769 2770 2771 2772
					 sizeof(*mod->trace_events),
					 &mod->num_trace_events);
	/*
	 * This section contains pointers to allocated objects in the trace
	 * code and not scanning it leads to false positives.
	 */
	kmemleak_scan_area(mod->trace_events, sizeof(*mod->trace_events) *
			   mod->num_trace_events, GFP_KERNEL);
#endif
2773 2774 2775 2776 2777 2778 2779 2780 2781 2782 2783 2784
#ifdef CONFIG_TRACING
	mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
					 sizeof(*mod->trace_bprintk_fmt_start),
					 &mod->num_trace_bprintk_fmt);
	/*
	 * This section contains pointers to allocated objects in the trace
	 * code and not scanning it leads to false positives.
	 */
	kmemleak_scan_area(mod->trace_bprintk_fmt_start,
			   sizeof(*mod->trace_bprintk_fmt_start) *
			   mod->num_trace_bprintk_fmt, GFP_KERNEL);
#endif
2785 2786
#ifdef CONFIG_FTRACE_MCOUNT_RECORD
	/* sechdrs[0].sh_size is always zero */
2787
	mod->ftrace_callsites = section_objs(info, "__mcount_loc",
2788 2789 2790
					     sizeof(*mod->ftrace_callsites),
					     &mod->num_ftrace_callsites);
#endif
2791

2792 2793 2794
	mod->extable = section_objs(info, "__ex_table",
				    sizeof(*mod->extable), &mod->num_exentries);

2795
	if (section_addr(info, "__obsparm"))
2796 2797
		printk(KERN_WARNING "%s: Ignoring obsolete parameters\n",
		       mod->name);
2798 2799 2800

	info->debug = section_objs(info, "__verbose",
				   sizeof(*info->debug), &info->num_debug);
2801 2802
}

2803
static int move_module(struct module *mod, struct load_info *info)
2804 2805 2806 2807 2808 2809 2810 2811 2812 2813 2814 2815 2816
{
	int i;
	void *ptr;

	/* Do the allocs. */
	ptr = module_alloc_update_bounds(mod->core_size);
	/*
	 * The pointer to this block is stored in the module structure
	 * which is inside the block. Just mark it as not being a
	 * leak.
	 */
	kmemleak_not_leak(ptr);
	if (!ptr)
2817
		return -ENOMEM;
2818 2819 2820 2821

	memset(ptr, 0, mod->core_size);
	mod->module_core = ptr;

2822 2823 2824 2825 2826 2827 2828 2829 2830 2831 2832 2833 2834 2835 2836 2837 2838
	if (mod->init_size) {
		ptr = module_alloc_update_bounds(mod->init_size);
		/*
		 * The pointer to this block is stored in the module structure
		 * which is inside the block. This block doesn't need to be
		 * scanned as it contains data and code that will be freed
		 * after the module is initialized.
		 */
		kmemleak_ignore(ptr);
		if (!ptr) {
			module_free(mod, mod->module_core);
			return -ENOMEM;
		}
		memset(ptr, 0, mod->init_size);
		mod->module_init = ptr;
	} else
		mod->module_init = NULL;
2839 2840

	/* Transfer each section which specifies SHF_ALLOC */
2841
	pr_debug("final section addresses:\n");
2842
	for (i = 0; i < info->hdr->e_shnum; i++) {
2843
		void *dest;
2844
		Elf_Shdr *shdr = &info->sechdrs[i];
2845

2846
		if (!(shdr->sh_flags & SHF_ALLOC))
2847 2848
			continue;

2849
		if (shdr->sh_entsize & INIT_OFFSET_MASK)
2850
			dest = mod->module_init
2851
				+ (shdr->sh_entsize & ~INIT_OFFSET_MASK);
2852
		else
2853
			dest = mod->module_core + shdr->sh_entsize;
2854

2855 2856
		if (shdr->sh_type != SHT_NOBITS)
			memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
2857
		/* Update sh_addr to point to copy in image. */
2858
		shdr->sh_addr = (unsigned long)dest;
2859 2860
		pr_debug("\t0x%lx %s\n",
			 (long)shdr->sh_addr, info->secstrings + shdr->sh_name);
2861
	}
2862 2863

	return 0;
2864 2865
}

2866
static int check_module_license_and_versions(struct module *mod)
2867 2868 2869 2870 2871 2872 2873
{
	/*
	 * ndiswrapper is under GPL by itself, but loads proprietary modules.
	 * Don't use add_taint_module(), as it would prevent ndiswrapper from
	 * using GPL-only symbols it needs.
	 */
	if (strcmp(mod->name, "ndiswrapper") == 0)
2874
		add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
2875 2876 2877

	/* driverloader was caught wrongly pretending to be under GPL */
	if (strcmp(mod->name, "driverloader") == 0)
2878 2879
		add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
				 LOCKDEP_NOW_UNRELIABLE);
2880

2881 2882
	/* lve claims to be GPL but upstream won't provide source */
	if (strcmp(mod->name, "lve") == 0)
2883 2884
		add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
				 LOCKDEP_NOW_UNRELIABLE);
2885

2886 2887 2888 2889 2890 2891 2892 2893 2894 2895 2896 2897 2898 2899 2900 2901 2902 2903 2904 2905 2906 2907 2908 2909 2910 2911 2912 2913 2914 2915 2916 2917 2918 2919 2920 2921 2922 2923 2924
#ifdef CONFIG_MODVERSIONS
	if ((mod->num_syms && !mod->crcs)
	    || (mod->num_gpl_syms && !mod->gpl_crcs)
	    || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
#ifdef CONFIG_UNUSED_SYMBOLS
	    || (mod->num_unused_syms && !mod->unused_crcs)
	    || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
#endif
		) {
		return try_to_force_load(mod,
					 "no versions for exported symbols");
	}
#endif
	return 0;
}

static void flush_module_icache(const struct module *mod)
{
	mm_segment_t old_fs;

	/* flush the icache in correct context */
	old_fs = get_fs();
	set_fs(KERNEL_DS);

	/*
	 * Flush the instruction cache, since we've played with text.
	 * Do it before processing of module parameters, so the module
	 * can provide parameter accessor functions of its own.
	 */
	if (mod->module_init)
		flush_icache_range((unsigned long)mod->module_init,
				   (unsigned long)mod->module_init
				   + mod->init_size);
	flush_icache_range((unsigned long)mod->module_core,
			   (unsigned long)mod->module_core + mod->core_size);

	set_fs(old_fs);
}

2925 2926 2927 2928 2929 2930 2931 2932
int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
				     Elf_Shdr *sechdrs,
				     char *secstrings,
				     struct module *mod)
{
	return 0;
}

2933
static struct module *layout_and_allocate(struct load_info *info, int flags)
L
Linus Torvalds 已提交
2934
{
2935
	/* Module within temporary copy. */
L
Linus Torvalds 已提交
2936
	struct module *mod;
2937
	Elf_Shdr *pcpusec;
2938
	int err;
2939

2940
	mod = setup_load_info(info, flags);
2941 2942
	if (IS_ERR(mod))
		return mod;
L
Linus Torvalds 已提交
2943

2944
	err = check_modinfo(mod, info, flags);
2945 2946
	if (err)
		return ERR_PTR(err);
L
Linus Torvalds 已提交
2947 2948

	/* Allow arches to frob section contents and sizes.  */
2949 2950
	err = module_frob_arch_sections(info->hdr, info->sechdrs,
					info->secstrings, mod);
L
Linus Torvalds 已提交
2951
	if (err < 0)
2952
		goto out;
L
Linus Torvalds 已提交
2953

2954 2955
	pcpusec = &info->sechdrs[info->index.pcpu];
	if (pcpusec->sh_size) {
L
Linus Torvalds 已提交
2956
		/* We have a special allocation for this section. */
2957 2958
		err = percpu_modalloc(mod,
				      pcpusec->sh_size, pcpusec->sh_addralign);
2959
		if (err)
2960
			goto out;
2961
		pcpusec->sh_flags &= ~(unsigned long)SHF_ALLOC;
L
Linus Torvalds 已提交
2962 2963 2964 2965 2966
	}

	/* Determine total sizes, and put offsets in sh_entsize.  For now
	   this is done generically; there doesn't appear to be any
	   special cases for the architectures. */
2967 2968
	layout_sections(mod, info);
	layout_symtab(mod, info);
L
Linus Torvalds 已提交
2969

2970
	/* Allocate and move to the final place */
2971
	err = move_module(mod, info);
2972
	if (err)
2973
		goto free_percpu;
2974 2975 2976

	/* Module has been copied to its final place now: return it. */
	mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2977
	kmemleak_load_module(mod, info);
2978 2979 2980 2981
	return mod;

free_percpu:
	percpu_modfree(mod);
2982
out:
2983 2984 2985 2986 2987 2988 2989 2990 2991 2992 2993
	return ERR_PTR(err);
}

/* mod is no longer valid after this! */
static void module_deallocate(struct module *mod, struct load_info *info)
{
	percpu_modfree(mod);
	module_free(mod, mod->module_init);
	module_free(mod, mod->module_core);
}

2994 2995 2996 2997 2998 2999 3000
int __weak module_finalize(const Elf_Ehdr *hdr,
			   const Elf_Shdr *sechdrs,
			   struct module *me)
{
	return 0;
}

3001 3002
static int post_relocation(struct module *mod, const struct load_info *info)
{
3003
	/* Sort exception table now relocations are done. */
3004 3005 3006 3007 3008 3009
	sort_extable(mod->extable, mod->extable + mod->num_exentries);

	/* Copy relocated percpu area over. */
	percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
		       info->sechdrs[info->index.pcpu].sh_size);

3010
	/* Setup kallsyms-specific fields. */
3011 3012 3013 3014 3015 3016
	add_kallsyms(mod, info);

	/* Arch-specific module finalizing. */
	return module_finalize(info->hdr, info->sechdrs, mod);
}

3017 3018 3019 3020 3021 3022 3023
/* Is this module of this name done loading?  No locks held. */
static bool finished_loading(const char *name)
{
	struct module *mod;
	bool ret;

	mutex_lock(&module_mutex);
3024
	mod = find_module_all(name, true);
3025 3026
	ret = !mod || mod->state == MODULE_STATE_LIVE
		|| mod->state == MODULE_STATE_GOING;
3027 3028 3029 3030 3031
	mutex_unlock(&module_mutex);

	return ret;
}

3032 3033 3034 3035 3036 3037 3038 3039 3040 3041 3042 3043 3044 3045 3046 3047
/* Call module constructors. */
static void do_mod_ctors(struct module *mod)
{
#ifdef CONFIG_CONSTRUCTORS
	unsigned long i;

	for (i = 0; i < mod->num_ctors; i++)
		mod->ctors[i]();
#endif
}

/* This is where the real work happens */
static int do_init_module(struct module *mod)
{
	int ret = 0;

3048 3049 3050 3051 3052 3053
	/*
	 * We want to find out whether @mod uses async during init.  Clear
	 * PF_USED_ASYNC.  async_schedule*() will set it.
	 */
	current->flags &= ~PF_USED_ASYNC;

3054 3055 3056 3057 3058 3059 3060 3061 3062 3063 3064 3065 3066 3067 3068 3069 3070 3071 3072 3073 3074 3075 3076 3077 3078 3079 3080 3081 3082 3083 3084 3085 3086 3087 3088 3089 3090 3091 3092 3093 3094 3095 3096 3097 3098
	blocking_notifier_call_chain(&module_notify_list,
			MODULE_STATE_COMING, mod);

	/* Set RO and NX regions for core */
	set_section_ro_nx(mod->module_core,
				mod->core_text_size,
				mod->core_ro_size,
				mod->core_size);

	/* Set RO and NX regions for init */
	set_section_ro_nx(mod->module_init,
				mod->init_text_size,
				mod->init_ro_size,
				mod->init_size);

	do_mod_ctors(mod);
	/* Start the module */
	if (mod->init != NULL)
		ret = do_one_initcall(mod->init);
	if (ret < 0) {
		/* Init routine failed: abort.  Try to protect us from
                   buggy refcounters. */
		mod->state = MODULE_STATE_GOING;
		synchronize_sched();
		module_put(mod);
		blocking_notifier_call_chain(&module_notify_list,
					     MODULE_STATE_GOING, mod);
		free_module(mod);
		wake_up_all(&module_wq);
		return ret;
	}
	if (ret > 0) {
		printk(KERN_WARNING
"%s: '%s'->init suspiciously returned %d, it should follow 0/-E convention\n"
"%s: loading module anyway...\n",
		       __func__, mod->name, ret,
		       __func__);
		dump_stack();
	}

	/* Now it's a first class citizen! */
	mod->state = MODULE_STATE_LIVE;
	blocking_notifier_call_chain(&module_notify_list,
				     MODULE_STATE_LIVE, mod);

3099 3100 3101 3102 3103 3104 3105 3106 3107 3108 3109 3110 3111 3112 3113 3114 3115 3116 3117
	/*
	 * We need to finish all async code before the module init sequence
	 * is done.  This has potential to deadlock.  For example, a newly
	 * detected block device can trigger request_module() of the
	 * default iosched from async probing task.  Once userland helper
	 * reaches here, async_synchronize_full() will wait on the async
	 * task waiting on request_module() and deadlock.
	 *
	 * This deadlock is avoided by perfomring async_synchronize_full()
	 * iff module init queued any async jobs.  This isn't a full
	 * solution as it will deadlock the same if module loading from
	 * async jobs nests more than once; however, due to the various
	 * constraints, this hack seems to be the best option for now.
	 * Please refer to the following thread for details.
	 *
	 * http://thread.gmane.org/gmane.linux.kernel/1420814
	 */
	if (current->flags & PF_USED_ASYNC)
		async_synchronize_full();
3118 3119 3120 3121 3122 3123 3124 3125 3126 3127 3128 3129 3130 3131 3132 3133 3134 3135 3136 3137 3138 3139 3140 3141 3142 3143 3144 3145 3146 3147

	mutex_lock(&module_mutex);
	/* Drop initial reference. */
	module_put(mod);
	trim_init_extable(mod);
#ifdef CONFIG_KALLSYMS
	mod->num_symtab = mod->core_num_syms;
	mod->symtab = mod->core_symtab;
	mod->strtab = mod->core_strtab;
#endif
	unset_module_init_ro_nx(mod);
	module_free(mod, mod->module_init);
	mod->module_init = NULL;
	mod->init_size = 0;
	mod->init_ro_size = 0;
	mod->init_text_size = 0;
	mutex_unlock(&module_mutex);
	wake_up_all(&module_wq);

	return 0;
}

static int may_init_module(void)
{
	if (!capable(CAP_SYS_MODULE) || modules_disabled)
		return -EPERM;

	return 0;
}

3148 3149 3150 3151 3152 3153 3154 3155 3156 3157 3158 3159 3160 3161 3162 3163 3164 3165 3166 3167 3168 3169 3170 3171 3172 3173 3174 3175 3176 3177 3178 3179 3180 3181 3182 3183 3184 3185 3186 3187 3188 3189 3190 3191 3192 3193 3194 3195 3196 3197 3198 3199 3200 3201 3202 3203 3204 3205 3206 3207
/*
 * We try to place it in the list now to make sure it's unique before
 * we dedicate too many resources.  In particular, temporary percpu
 * memory exhaustion.
 */
static int add_unformed_module(struct module *mod)
{
	int err;
	struct module *old;

	mod->state = MODULE_STATE_UNFORMED;

again:
	mutex_lock(&module_mutex);
	if ((old = find_module_all(mod->name, true)) != NULL) {
		if (old->state == MODULE_STATE_COMING
		    || old->state == MODULE_STATE_UNFORMED) {
			/* Wait in case it fails to load. */
			mutex_unlock(&module_mutex);
			err = wait_event_interruptible(module_wq,
					       finished_loading(mod->name));
			if (err)
				goto out_unlocked;
			goto again;
		}
		err = -EEXIST;
		goto out;
	}
	list_add_rcu(&mod->list, &modules);
	err = 0;

out:
	mutex_unlock(&module_mutex);
out_unlocked:
	return err;
}

static int complete_formation(struct module *mod, struct load_info *info)
{
	int err;

	mutex_lock(&module_mutex);

	/* Find duplicate symbols (must be called under lock). */
	err = verify_export_symbols(mod);
	if (err < 0)
		goto out;

	/* This relies on module_mutex for list integrity. */
	module_bug_finalize(info->hdr, info->sechdrs, mod);

	/* Mark state as coming so strong_try_module_get() ignores us,
	 * but kallsyms etc. can see us. */
	mod->state = MODULE_STATE_COMING;

out:
	mutex_unlock(&module_mutex);
	return err;
}

3208 3209
/* Allocate and load the module: note that size of section 0 is always
   zero, and we rely on this for optional sections. */
3210 3211
static int load_module(struct load_info *info, const char __user *uargs,
		       int flags)
3212
{
3213
	struct module *mod;
3214 3215
	long err;

3216 3217 3218
	err = module_sig_check(info);
	if (err)
		goto free_copy;
3219

3220
	err = elf_header_check(info);
3221
	if (err)
3222
		goto free_copy;
3223 3224

	/* Figure out module layout, and allocate all the memory. */
3225
	mod = layout_and_allocate(info, flags);
3226 3227
	if (IS_ERR(mod)) {
		err = PTR_ERR(mod);
3228
		goto free_copy;
L
Linus Torvalds 已提交
3229 3230
	}

3231 3232 3233
	/* Reserve our place in the list. */
	err = add_unformed_module(mod);
	if (err)
3234 3235
		goto free_module;

3236
#ifdef CONFIG_MODULE_SIG
3237
	mod->sig_ok = info->sig_ok;
3238 3239 3240 3241 3242
	if (!mod->sig_ok) {
		printk_once(KERN_NOTICE
			    "%s: module verification failed: signature and/or"
			    " required key missing - tainting kernel\n",
			    mod->name);
3243
		add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_STILL_OK);
3244
	}
3245 3246
#endif

3247
	/* Now module is in final location, initialize linked lists, etc. */
3248 3249
	err = module_unload_init(mod);
	if (err)
3250
		goto unlink_mod;
L
Linus Torvalds 已提交
3251

3252 3253
	/* Now we've got everything in the final locations, we can
	 * find optional sections. */
3254
	find_module_sections(mod, info);
3255

3256
	err = check_module_license_and_versions(mod);
3257 3258
	if (err)
		goto free_unload;
3259

3260
	/* Set up MODINFO_ATTR fields */
3261
	setup_modinfo(mod, info);
3262

L
Linus Torvalds 已提交
3263
	/* Fix up syms, so that st_value is a pointer to location. */
3264
	err = simplify_symbols(mod, info);
L
Linus Torvalds 已提交
3265
	if (err < 0)
3266
		goto free_modinfo;
L
Linus Torvalds 已提交
3267

3268
	err = apply_relocations(mod, info);
3269
	if (err < 0)
3270
		goto free_modinfo;
L
Linus Torvalds 已提交
3271

3272
	err = post_relocation(mod, info);
L
Linus Torvalds 已提交
3273
	if (err < 0)
3274
		goto free_modinfo;
L
Linus Torvalds 已提交
3275

3276
	flush_module_icache(mod);
3277

3278 3279 3280 3281 3282 3283
	/* Now copy in args */
	mod->args = strndup_user(uargs, ~0UL >> 1);
	if (IS_ERR(mod->args)) {
		err = PTR_ERR(mod->args);
		goto free_arch_cleanup;
	}
3284

3285
	dynamic_debug_setup(info->debug, info->num_debug);
3286

3287 3288 3289
	/* Finally it's fully formed, ready to start executing. */
	err = complete_formation(mod, info);
	if (err)
3290
		goto ddebug_cleanup;
3291

3292
	/* Module is ready to execute: parsing args may do that. */
3293
	err = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
3294
			 -32768, 32767, &ddebug_dyndbg_module_param_cb);
L
Linus Torvalds 已提交
3295
	if (err < 0)
3296
		goto bug_cleanup;
L
Linus Torvalds 已提交
3297

3298
	/* Link in to syfs. */
3299
	err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
L
Linus Torvalds 已提交
3300
	if (err < 0)
3301
		goto bug_cleanup;
3302

3303
	/* Get rid of temporary copy. */
3304
	free_copy(info);
L
Linus Torvalds 已提交
3305 3306

	/* Done! */
3307
	trace_module_load(mod);
3308 3309

	return do_init_module(mod);
L
Linus Torvalds 已提交
3310

3311 3312
 bug_cleanup:
	/* module_bug_cleanup needs module_mutex protection */
3313
	mutex_lock(&module_mutex);
3314
	module_bug_cleanup(mod);
3315
	mutex_unlock(&module_mutex);
3316
 ddebug_cleanup:
3317
	dynamic_debug_remove(info->debug);
3318
	synchronize_sched();
3319 3320
	kfree(mod->args);
 free_arch_cleanup:
L
Linus Torvalds 已提交
3321
	module_arch_cleanup(mod);
3322
 free_modinfo:
3323
	free_modinfo(mod);
3324
 free_unload:
L
Linus Torvalds 已提交
3325
	module_unload_free(mod);
3326 3327 3328 3329 3330 3331
 unlink_mod:
	mutex_lock(&module_mutex);
	/* Unlink carefully: kallsyms could be walking list. */
	list_del_rcu(&mod->list);
	wake_up_all(&module_wq);
	mutex_unlock(&module_mutex);
3332
 free_module:
3333
	module_deallocate(mod, info);
3334
 free_copy:
3335 3336
	free_copy(info);
	return err;
3337 3338
}

3339 3340
SYSCALL_DEFINE3(init_module, void __user *, umod,
		unsigned long, len, const char __user *, uargs)
L
Linus Torvalds 已提交
3341
{
3342 3343
	int err;
	struct load_info info = { };
L
Linus Torvalds 已提交
3344

3345 3346 3347
	err = may_init_module();
	if (err)
		return err;
L
Linus Torvalds 已提交
3348

3349 3350
	pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
	       umod, len, uargs);
L
Linus Torvalds 已提交
3351

3352 3353 3354
	err = copy_module_from_user(umod, len, &info);
	if (err)
		return err;
L
Linus Torvalds 已提交
3355

3356
	return load_module(&info, uargs, 0);
3357
}
3358

3359
SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
3360 3361 3362
{
	int err;
	struct load_info info = { };
3363

3364 3365 3366
	err = may_init_module();
	if (err)
		return err;
L
Linus Torvalds 已提交
3367

3368
	pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags);
3369

3370 3371 3372
	if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS
		      |MODULE_INIT_IGNORE_VERMAGIC))
		return -EINVAL;
3373

3374 3375 3376
	err = copy_module_from_fd(fd, &info);
	if (err)
		return err;
L
Linus Torvalds 已提交
3377

3378
	return load_module(&info, uargs, flags);
L
Linus Torvalds 已提交
3379 3380 3381 3382 3383 3384 3385 3386 3387 3388 3389 3390 3391 3392
}

static inline int within(unsigned long addr, void *start, unsigned long size)
{
	return ((void *)addr >= start && (void *)addr < start + size);
}

#ifdef CONFIG_KALLSYMS
/*
 * This ignores the intensely annoying "mapping symbols" found
 * in ARM ELF files: $a, $t and $d.
 */
static inline int is_arm_mapping_symbol(const char *str)
{
3393
	return str[0] == '$' && strchr("atd", str[1])
L
Linus Torvalds 已提交
3394 3395 3396 3397 3398 3399 3400 3401 3402 3403 3404 3405
	       && (str[2] == '\0' || str[2] == '.');
}

static const char *get_ksymbol(struct module *mod,
			       unsigned long addr,
			       unsigned long *size,
			       unsigned long *offset)
{
	unsigned int i, best = 0;
	unsigned long nextval;

	/* At worse, next value is at end of module */
3406
	if (within_module_init(addr, mod))
L
Linus Torvalds 已提交
3407
		nextval = (unsigned long)mod->module_init+mod->init_text_size;
3408
	else
L
Linus Torvalds 已提交
3409 3410
		nextval = (unsigned long)mod->module_core+mod->core_text_size;

L
Lucas De Marchi 已提交
3411
	/* Scan for closest preceding symbol, and next symbol. (ELF
3412
	   starts real symbols at 1). */
L
Linus Torvalds 已提交
3413 3414 3415 3416 3417 3418 3419 3420 3421 3422 3423 3424 3425 3426 3427 3428 3429 3430 3431 3432 3433
	for (i = 1; i < mod->num_symtab; i++) {
		if (mod->symtab[i].st_shndx == SHN_UNDEF)
			continue;

		/* We ignore unnamed symbols: they're uninformative
		 * and inserted at a whim. */
		if (mod->symtab[i].st_value <= addr
		    && mod->symtab[i].st_value > mod->symtab[best].st_value
		    && *(mod->strtab + mod->symtab[i].st_name) != '\0'
		    && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
			best = i;
		if (mod->symtab[i].st_value > addr
		    && mod->symtab[i].st_value < nextval
		    && *(mod->strtab + mod->symtab[i].st_name) != '\0'
		    && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
			nextval = mod->symtab[i].st_value;
	}

	if (!best)
		return NULL;

3434 3435 3436 3437
	if (size)
		*size = nextval - mod->symtab[best].st_value;
	if (offset)
		*offset = addr - mod->symtab[best].st_value;
L
Linus Torvalds 已提交
3438 3439 3440
	return mod->strtab + mod->symtab[best].st_name;
}

3441 3442
/* For kallsyms to ask for address resolution.  NULL means not found.  Careful
 * not to lock to avoid deadlock on oopses, simply disable preemption. */
3443
const char *module_address_lookup(unsigned long addr,
3444 3445 3446 3447
			    unsigned long *size,
			    unsigned long *offset,
			    char **modname,
			    char *namebuf)
L
Linus Torvalds 已提交
3448 3449
{
	struct module *mod;
3450
	const char *ret = NULL;
L
Linus Torvalds 已提交
3451

3452
	preempt_disable();
3453
	list_for_each_entry_rcu(mod, &modules, list) {
3454 3455
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
3456 3457
		if (within_module_init(addr, mod) ||
		    within_module_core(addr, mod)) {
3458 3459
			if (modname)
				*modname = mod->name;
3460 3461
			ret = get_ksymbol(mod, addr, size, offset);
			break;
L
Linus Torvalds 已提交
3462 3463
		}
	}
3464 3465 3466 3467 3468
	/* Make a copy in here where it's safe */
	if (ret) {
		strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
		ret = namebuf;
	}
3469
	preempt_enable();
3470
	return ret;
L
Linus Torvalds 已提交
3471 3472
}

3473 3474 3475 3476
int lookup_module_symbol_name(unsigned long addr, char *symname)
{
	struct module *mod;

3477
	preempt_disable();
3478
	list_for_each_entry_rcu(mod, &modules, list) {
3479 3480
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
3481 3482
		if (within_module_init(addr, mod) ||
		    within_module_core(addr, mod)) {
3483 3484 3485 3486 3487
			const char *sym;

			sym = get_ksymbol(mod, addr, NULL, NULL);
			if (!sym)
				goto out;
3488
			strlcpy(symname, sym, KSYM_NAME_LEN);
3489
			preempt_enable();
3490 3491 3492 3493
			return 0;
		}
	}
out:
3494
	preempt_enable();
3495 3496 3497
	return -ERANGE;
}

3498 3499 3500 3501 3502
int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
			unsigned long *offset, char *modname, char *name)
{
	struct module *mod;

3503
	preempt_disable();
3504
	list_for_each_entry_rcu(mod, &modules, list) {
3505 3506
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
3507 3508
		if (within_module_init(addr, mod) ||
		    within_module_core(addr, mod)) {
3509 3510 3511 3512 3513 3514
			const char *sym;

			sym = get_ksymbol(mod, addr, size, offset);
			if (!sym)
				goto out;
			if (modname)
3515
				strlcpy(modname, mod->name, MODULE_NAME_LEN);
3516
			if (name)
3517
				strlcpy(name, sym, KSYM_NAME_LEN);
3518
			preempt_enable();
3519 3520 3521 3522
			return 0;
		}
	}
out:
3523
	preempt_enable();
3524 3525 3526
	return -ERANGE;
}

3527 3528
int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
			char *name, char *module_name, int *exported)
L
Linus Torvalds 已提交
3529 3530 3531
{
	struct module *mod;

3532
	preempt_disable();
3533
	list_for_each_entry_rcu(mod, &modules, list) {
3534 3535
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
L
Linus Torvalds 已提交
3536 3537 3538
		if (symnum < mod->num_symtab) {
			*value = mod->symtab[symnum].st_value;
			*type = mod->symtab[symnum].st_info;
3539
			strlcpy(name, mod->strtab + mod->symtab[symnum].st_name,
3540 3541
				KSYM_NAME_LEN);
			strlcpy(module_name, mod->name, MODULE_NAME_LEN);
3542
			*exported = is_exported(name, *value, mod);
3543
			preempt_enable();
3544
			return 0;
L
Linus Torvalds 已提交
3545 3546 3547
		}
		symnum -= mod->num_symtab;
	}
3548
	preempt_enable();
3549
	return -ERANGE;
L
Linus Torvalds 已提交
3550 3551 3552 3553 3554 3555 3556
}

static unsigned long mod_find_symname(struct module *mod, const char *name)
{
	unsigned int i;

	for (i = 0; i < mod->num_symtab; i++)
3557 3558
		if (strcmp(name, mod->strtab+mod->symtab[i].st_name) == 0 &&
		    mod->symtab[i].st_info != 'U')
L
Linus Torvalds 已提交
3559 3560 3561 3562 3563 3564 3565 3566 3567 3568 3569 3570
			return mod->symtab[i].st_value;
	return 0;
}

/* Look for this name: can be of form module:name. */
unsigned long module_kallsyms_lookup_name(const char *name)
{
	struct module *mod;
	char *colon;
	unsigned long ret = 0;

	/* Don't lock: we're in enough trouble already. */
3571
	preempt_disable();
L
Linus Torvalds 已提交
3572 3573 3574 3575 3576 3577
	if ((colon = strchr(name, ':')) != NULL) {
		*colon = '\0';
		if ((mod = find_module(name)) != NULL)
			ret = mod_find_symname(mod, colon+1);
		*colon = ':';
	} else {
3578 3579 3580
		list_for_each_entry_rcu(mod, &modules, list) {
			if (mod->state == MODULE_STATE_UNFORMED)
				continue;
L
Linus Torvalds 已提交
3581 3582
			if ((ret = mod_find_symname(mod, name)) != 0)
				break;
3583
		}
L
Linus Torvalds 已提交
3584
	}
3585
	preempt_enable();
L
Linus Torvalds 已提交
3586 3587
	return ret;
}
3588 3589 3590 3591 3592 3593 3594 3595 3596 3597

int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
					     struct module *, unsigned long),
				   void *data)
{
	struct module *mod;
	unsigned int i;
	int ret;

	list_for_each_entry(mod, &modules, list) {
3598 3599
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
3600 3601 3602 3603 3604 3605 3606 3607 3608
		for (i = 0; i < mod->num_symtab; i++) {
			ret = fn(data, mod->strtab + mod->symtab[i].st_name,
				 mod, mod->symtab[i].st_value);
			if (ret != 0)
				return ret;
		}
	}
	return 0;
}
L
Linus Torvalds 已提交
3609 3610
#endif /* CONFIG_KALLSYMS */

3611
static char *module_flags(struct module *mod, char *buf)
3612 3613 3614
{
	int bx = 0;

3615
	BUG_ON(mod->state == MODULE_STATE_UNFORMED);
3616 3617 3618
	if (mod->taints ||
	    mod->state == MODULE_STATE_GOING ||
	    mod->state == MODULE_STATE_COMING) {
3619
		buf[bx++] = '(';
3620
		bx += module_flags_taint(mod, buf + bx);
3621 3622 3623 3624 3625 3626
		/* Show a - for module-is-being-unloaded */
		if (mod->state == MODULE_STATE_GOING)
			buf[bx++] = '-';
		/* Show a + for module-is-being-loaded */
		if (mod->state == MODULE_STATE_COMING)
			buf[bx++] = '+';
3627 3628 3629 3630 3631 3632 3633
		buf[bx++] = ')';
	}
	buf[bx] = '\0';

	return buf;
}

3634 3635 3636 3637 3638 3639 3640 3641 3642 3643 3644 3645 3646 3647 3648 3649 3650 3651
#ifdef CONFIG_PROC_FS
/* Called by the /proc file system to return a list of modules. */
static void *m_start(struct seq_file *m, loff_t *pos)
{
	mutex_lock(&module_mutex);
	return seq_list_start(&modules, *pos);
}

static void *m_next(struct seq_file *m, void *p, loff_t *pos)
{
	return seq_list_next(p, &modules, pos);
}

static void m_stop(struct seq_file *m, void *p)
{
	mutex_unlock(&module_mutex);
}

L
Linus Torvalds 已提交
3652 3653 3654
static int m_show(struct seq_file *m, void *p)
{
	struct module *mod = list_entry(p, struct module, list);
3655 3656
	char buf[8];

3657 3658 3659 3660
	/* We always ignore unformed modules. */
	if (mod->state == MODULE_STATE_UNFORMED)
		return 0;

3661
	seq_printf(m, "%s %u",
L
Linus Torvalds 已提交
3662 3663 3664 3665 3666 3667 3668 3669 3670
		   mod->name, mod->init_size + mod->core_size);
	print_unload_info(m, mod);

	/* Informative for users. */
	seq_printf(m, " %s",
		   mod->state == MODULE_STATE_GOING ? "Unloading":
		   mod->state == MODULE_STATE_COMING ? "Loading":
		   "Live");
	/* Used by oprofile and other similar tools. */
3671
	seq_printf(m, " 0x%pK", mod->module_core);
L
Linus Torvalds 已提交
3672

3673 3674
	/* Taints info */
	if (mod->taints)
3675
		seq_printf(m, " %s", module_flags(mod, buf));
3676

L
Linus Torvalds 已提交
3677 3678 3679 3680 3681 3682 3683 3684 3685
	seq_printf(m, "\n");
	return 0;
}

/* Format: modulename size refcount deps address

   Where refcount is a number or -, and deps is a comma-separated list
   of depends or -.
*/
3686
static const struct seq_operations modules_op = {
L
Linus Torvalds 已提交
3687 3688 3689 3690 3691 3692
	.start	= m_start,
	.next	= m_next,
	.stop	= m_stop,
	.show	= m_show
};

3693 3694 3695 3696 3697 3698 3699 3700 3701 3702 3703 3704 3705 3706 3707 3708 3709 3710 3711 3712
static int modules_open(struct inode *inode, struct file *file)
{
	return seq_open(file, &modules_op);
}

static const struct file_operations proc_modules_operations = {
	.open		= modules_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= seq_release,
};

static int __init proc_modules_init(void)
{
	proc_create("modules", 0, NULL, &proc_modules_operations);
	return 0;
}
module_init(proc_modules_init);
#endif

L
Linus Torvalds 已提交
3713 3714 3715 3716 3717 3718
/* Given an address, look for it in the module exception tables. */
const struct exception_table_entry *search_module_extables(unsigned long addr)
{
	const struct exception_table_entry *e = NULL;
	struct module *mod;

3719
	preempt_disable();
3720
	list_for_each_entry_rcu(mod, &modules, list) {
3721 3722
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
L
Linus Torvalds 已提交
3723 3724
		if (mod->num_exentries == 0)
			continue;
3725

L
Linus Torvalds 已提交
3726 3727 3728 3729 3730 3731
		e = search_extable(mod->extable,
				   mod->extable + mod->num_exentries - 1,
				   addr);
		if (e)
			break;
	}
3732
	preempt_enable();
L
Linus Torvalds 已提交
3733 3734

	/* Now, if we found one, we are running inside it now, hence
3735
	   we cannot unload the module, hence no refcnt needed. */
L
Linus Torvalds 已提交
3736 3737 3738
	return e;
}

3739
/*
R
Rusty Russell 已提交
3740 3741 3742 3743 3744
 * is_module_address - is this address inside a module?
 * @addr: the address to check.
 *
 * See is_module_text_address() if you simply want to see if the address
 * is code (not data).
3745
 */
R
Rusty Russell 已提交
3746
bool is_module_address(unsigned long addr)
3747
{
R
Rusty Russell 已提交
3748
	bool ret;
3749

3750
	preempt_disable();
R
Rusty Russell 已提交
3751
	ret = __module_address(addr) != NULL;
3752
	preempt_enable();
3753

R
Rusty Russell 已提交
3754
	return ret;
3755 3756
}

R
Rusty Russell 已提交
3757 3758 3759 3760 3761 3762 3763
/*
 * __module_address - get the module which contains an address.
 * @addr: the address.
 *
 * Must be called with preempt disabled or module mutex held so that
 * module doesn't get freed during this.
 */
3764
struct module *__module_address(unsigned long addr)
L
Linus Torvalds 已提交
3765 3766 3767
{
	struct module *mod;

3768 3769 3770
	if (addr < module_addr_min || addr > module_addr_max)
		return NULL;

3771 3772 3773
	list_for_each_entry_rcu(mod, &modules, list) {
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
R
Rusty Russell 已提交
3774 3775
		if (within_module_core(addr, mod)
		    || within_module_init(addr, mod))
L
Linus Torvalds 已提交
3776
			return mod;
3777
	}
L
Linus Torvalds 已提交
3778 3779
	return NULL;
}
3780
EXPORT_SYMBOL_GPL(__module_address);
L
Linus Torvalds 已提交
3781

R
Rusty Russell 已提交
3782 3783 3784 3785 3786 3787 3788 3789 3790 3791 3792 3793 3794 3795 3796 3797 3798 3799 3800 3801 3802 3803 3804 3805 3806 3807 3808 3809 3810 3811 3812 3813 3814 3815 3816 3817 3818
/*
 * is_module_text_address - is this address inside module code?
 * @addr: the address to check.
 *
 * See is_module_address() if you simply want to see if the address is
 * anywhere in a module.  See kernel_text_address() for testing if an
 * address corresponds to kernel or module code.
 */
bool is_module_text_address(unsigned long addr)
{
	bool ret;

	preempt_disable();
	ret = __module_text_address(addr) != NULL;
	preempt_enable();

	return ret;
}

/*
 * __module_text_address - get the module whose code contains an address.
 * @addr: the address.
 *
 * Must be called with preempt disabled or module mutex held so that
 * module doesn't get freed during this.
 */
struct module *__module_text_address(unsigned long addr)
{
	struct module *mod = __module_address(addr);
	if (mod) {
		/* Make sure it's within the text section. */
		if (!within(addr, mod->module_init, mod->init_text_size)
		    && !within(addr, mod->module_core, mod->core_text_size))
			mod = NULL;
	}
	return mod;
}
3819
EXPORT_SYMBOL_GPL(__module_text_address);
R
Rusty Russell 已提交
3820

L
Linus Torvalds 已提交
3821 3822 3823 3824
/* Don't grab lock, we're oopsing. */
void print_modules(void)
{
	struct module *mod;
3825
	char buf[8];
L
Linus Torvalds 已提交
3826

3827
	printk(KERN_DEFAULT "Modules linked in:");
3828 3829
	/* Most callers should already have preempt disabled, but make sure */
	preempt_disable();
3830 3831 3832
	list_for_each_entry_rcu(mod, &modules, list) {
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
3833
		printk(" %s%s", mod->name, module_flags(mod, buf));
3834
	}
3835
	preempt_enable();
3836 3837
	if (last_unloaded_module[0])
		printk(" [last unloaded: %s]", last_unloaded_module);
L
Linus Torvalds 已提交
3838 3839 3840 3841
	printk("\n");
}

#ifdef CONFIG_MODVERSIONS
3842 3843 3844 3845 3846 3847
/* Generate the signature for all relevant module structures here.
 * If these change, we don't want to try to parse the module. */
void module_layout(struct module *mod,
		   struct modversion_info *ver,
		   struct kernel_param *kp,
		   struct kernel_symbol *ks,
3848
		   struct tracepoint * const *tp)
3849 3850 3851
{
}
EXPORT_SYMBOL(module_layout);
L
Linus Torvalds 已提交
3852
#endif
反馈
建议
客服 返回
顶部