module.c 96.1 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
#include <linux/device.h>
46
#include <linux/string.h>
47
#include <linux/mutex.h>
48
#include <linux/rculist.h>
L
Linus Torvalds 已提交
49 50
#include <asm/uaccess.h>
#include <asm/cacheflush.h>
51
#include <asm/mmu_context.h>
52
#include <linux/license.h>
53
#include <asm/sections.h>
54
#include <linux/tracepoint.h>
55
#include <linux/ftrace.h>
56
#include <linux/async.h>
57
#include <linux/percpu.h>
58
#include <linux/kmemleak.h>
59
#include <linux/jump_label.h>
60
#include <linux/pfn.h>
61
#include <linux/bsearch.h>
62
#include <uapi/linux/module.h>
63
#include "module-internal.h"
L
Linus Torvalds 已提交
64

65 66 67
#define CREATE_TRACE_POINTS
#include <trace/events/module.h>

L
Linus Torvalds 已提交
68 69 70 71
#ifndef ARCH_SHF_SMALL
#define ARCH_SHF_SMALL 0
#endif

72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91
/*
 * 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
92 93 94
/* If this is set, the section belongs in the init part of the module */
#define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))

95 96 97 98 99
/*
 * Mutex protects:
 * 1) List of modules (also safely readable with preempt_disable),
 * 2) module_use links,
 * 3) module_addr_min/module_addr_max.
100
 * (delete and add uses RCU list operations). */
101 102
DEFINE_MUTEX(module_mutex);
EXPORT_SYMBOL_GPL(module_mutex);
L
Linus Torvalds 已提交
103
static LIST_HEAD(modules);
104 105 106 107
#ifdef CONFIG_KGDB_KDB
struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
#endif /* CONFIG_KGDB_KDB */

108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136
#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 = {
137
	.flags = KERNEL_PARAM_OPS_FL_NOARG,
138 139 140 141 142 143 144 145
	.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
146

147 148
/* Block module loading/unloading? */
int modules_disabled = 0;
149
core_param(nomodule, modules_disabled, bint, 0);
150

151 152 153
/* Waiting for a module to finish initializing? */
static DECLARE_WAIT_QUEUE_HEAD(module_wq);

154
static BLOCKING_NOTIFIER_HEAD(module_notify_list);
L
Linus Torvalds 已提交
155

156 157
/* Bounds of module allocation, for speeding __module_address.
 * Protected by module_mutex. */
158 159
static unsigned long module_addr_min = -1UL, module_addr_max = 0;

L
Linus Torvalds 已提交
160 161
int register_module_notifier(struct notifier_block * nb)
{
162
	return blocking_notifier_chain_register(&module_notify_list, nb);
L
Linus Torvalds 已提交
163 164 165 166 167
}
EXPORT_SYMBOL(register_module_notifier);

int unregister_module_notifier(struct notifier_block * nb)
{
168
	return blocking_notifier_chain_unregister(&module_notify_list, nb);
L
Linus Torvalds 已提交
169 170 171
}
EXPORT_SYMBOL(unregister_module_notifier);

172 173 174 175
struct load_info {
	Elf_Ehdr *hdr;
	unsigned long len;
	Elf_Shdr *sechdrs;
176
	char *secstrings, *strtab;
177
	unsigned long symoffs, stroffs;
178 179
	struct _ddebug *debug;
	unsigned int num_debug;
180
	bool sig_ok;
181 182 183 184 185
	struct {
		unsigned int sym, str, mod, vers, info, pcpu;
	} index;
};

186 187
/* We require a truly strong try_module_get(): 0 means failure due to
   ongoing or failed initialization etc. */
L
Linus Torvalds 已提交
188 189
static inline int strong_try_module_get(struct module *mod)
{
190
	BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED);
L
Linus Torvalds 已提交
191
	if (mod && mod->state == MODULE_STATE_COMING)
192 193
		return -EBUSY;
	if (try_module_get(mod))
L
Linus Torvalds 已提交
194
		return 0;
195 196
	else
		return -ENOENT;
L
Linus Torvalds 已提交
197 198
}

199 200
static inline void add_taint_module(struct module *mod, unsigned flag,
				    enum lockdep_ok lockdep_ok)
201
{
202
	add_taint(flag, lockdep_ok);
203
	mod->taints |= (1U << flag);
204 205
}

206 207 208
/*
 * 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
209 210 211 212 213 214 215
 */
void __module_put_and_exit(struct module *mod, long code)
{
	module_put(mod);
	do_exit(code);
}
EXPORT_SYMBOL(__module_put_and_exit);
216

L
Linus Torvalds 已提交
217
/* Find a module section: 0 means not found. */
218
static unsigned int find_sec(const struct load_info *info, const char *name)
L
Linus Torvalds 已提交
219 220 221
{
	unsigned int i;

222 223
	for (i = 1; i < info->hdr->e_shnum; i++) {
		Elf_Shdr *shdr = &info->sechdrs[i];
L
Linus Torvalds 已提交
224
		/* Alloc bit cleared means "ignore it." */
225 226
		if ((shdr->sh_flags & SHF_ALLOC)
		    && strcmp(info->secstrings + shdr->sh_name, name) == 0)
L
Linus Torvalds 已提交
227
			return i;
228
	}
L
Linus Torvalds 已提交
229 230 231
	return 0;
}

232
/* Find a module section, or NULL. */
233
static void *section_addr(const struct load_info *info, const char *name)
234 235
{
	/* Section 0 has sh_addr 0. */
236
	return (void *)info->sechdrs[find_sec(info, name)].sh_addr;
237 238 239
}

/* Find a module section, or NULL.  Fill in number of "objects" in section. */
240
static void *section_objs(const struct load_info *info,
241 242 243 244
			  const char *name,
			  size_t object_size,
			  unsigned int *num)
{
245
	unsigned int sec = find_sec(info, name);
246 247

	/* Section 0 has sh_addr 0 and sh_size 0. */
248 249
	*num = info->sechdrs[sec].sh_size / object_size;
	return (void *)info->sechdrs[sec].sh_addr;
250 251
}

L
Linus Torvalds 已提交
252 253 254 255 256
/* 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[];
257 258
extern const struct kernel_symbol __start___ksymtab_gpl_future[];
extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
L
Linus Torvalds 已提交
259 260
extern const unsigned long __start___kcrctab[];
extern const unsigned long __start___kcrctab_gpl[];
261
extern const unsigned long __start___kcrctab_gpl_future[];
262 263 264 265 266
#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[];
267 268
extern const unsigned long __start___kcrctab_unused[];
extern const unsigned long __start___kcrctab_unused_gpl[];
269
#endif
L
Linus Torvalds 已提交
270 271 272 273

#ifndef CONFIG_MODVERSIONS
#define symversion(base, idx) NULL
#else
274
#define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
L
Linus Torvalds 已提交
275 276
#endif

277 278 279 280 281
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,
282
					      void *data),
283
				   void *data)
284
{
285
	unsigned int j;
286

287
	for (j = 0; j < arrsize; j++) {
288 289
		if (fn(&arr[j], owner, data))
			return true;
290
	}
291 292

	return false;
293 294
}

295
/* Returns true as soon as fn returns true, otherwise false. */
296 297 298 299
bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
				    struct module *owner,
				    void *data),
			 void *data)
300 301
{
	struct module *mod;
302
	static const struct symsearch arr[] = {
303
		{ __start___ksymtab, __stop___ksymtab, __start___kcrctab,
304
		  NOT_GPL_ONLY, false },
305
		{ __start___ksymtab_gpl, __stop___ksymtab_gpl,
306 307
		  __start___kcrctab_gpl,
		  GPL_ONLY, false },
308
		{ __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future,
309 310
		  __start___kcrctab_gpl_future,
		  WILL_BE_GPL_ONLY, false },
311
#ifdef CONFIG_UNUSED_SYMBOLS
312
		{ __start___ksymtab_unused, __stop___ksymtab_unused,
313 314
		  __start___kcrctab_unused,
		  NOT_GPL_ONLY, true },
315
		{ __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl,
316 317
		  __start___kcrctab_unused_gpl,
		  GPL_ONLY, true },
318
#endif
319
	};
320

321 322
	if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data))
		return true;
323

324
	list_for_each_entry_rcu(mod, &modules, list) {
325 326
		struct symsearch arr[] = {
			{ mod->syms, mod->syms + mod->num_syms, mod->crcs,
327
			  NOT_GPL_ONLY, false },
328
			{ mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
329 330
			  mod->gpl_crcs,
			  GPL_ONLY, false },
331 332
			{ mod->gpl_future_syms,
			  mod->gpl_future_syms + mod->num_gpl_future_syms,
333 334
			  mod->gpl_future_crcs,
			  WILL_BE_GPL_ONLY, false },
335
#ifdef CONFIG_UNUSED_SYMBOLS
336 337
			{ mod->unused_syms,
			  mod->unused_syms + mod->num_unused_syms,
338 339
			  mod->unused_crcs,
			  NOT_GPL_ONLY, true },
340 341
			{ mod->unused_gpl_syms,
			  mod->unused_gpl_syms + mod->num_unused_gpl_syms,
342 343
			  mod->unused_gpl_crcs,
			  GPL_ONLY, true },
344
#endif
345 346
		};

347 348 349
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;

350 351 352 353 354
		if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data))
			return true;
	}
	return false;
}
355
EXPORT_SYMBOL_GPL(each_symbol_section);
356 357 358 359 360 361 362 363 364 365

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

	/* Output */
	struct module *owner;
	const unsigned long *crc;
366
	const struct kernel_symbol *sym;
367 368
};

369 370 371
static bool check_symbol(const struct symsearch *syms,
				 struct module *owner,
				 unsigned int symnum, void *data)
372 373 374 375 376 377 378
{
	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) {
379 380 381
			pr_warn("Symbol %s is being used by a non-GPL module, "
				"which will not be allowed in the future\n",
				fsa->name);
382
		}
L
Linus Torvalds 已提交
383
	}
384

385
#ifdef CONFIG_UNUSED_SYMBOLS
386
	if (syms->unused && fsa->warn) {
387 388 389 390 391 392 393
		pr_warn("Symbol %s is marked as UNUSED, however this module is "
			"using it.\n", fsa->name);
		pr_warn("This symbol will go away in the future.\n");
		pr_warn("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");
394
	}
395
#endif
396 397 398

	fsa->owner = owner;
	fsa->crc = symversion(syms->crcs, symnum);
399
	fsa->sym = &syms->start[symnum];
400 401 402
	return true;
}

403 404 405 406 407 408 409 410
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);
}

411 412 413 414 415
static bool find_symbol_in_section(const struct symsearch *syms,
				   struct module *owner,
				   void *data)
{
	struct find_symbol_arg *fsa = data;
416 417 418 419 420 421 422
	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;
423 424 425 426

	return false;
}

427
/* Find a symbol and return it, along with, (optional) crc and
428
 * (optional) module which owns it.  Needs preempt disabled or module_mutex. */
429 430 431 432 433
const struct kernel_symbol *find_symbol(const char *name,
					struct module **owner,
					const unsigned long **crc,
					bool gplok,
					bool warn)
434 435 436 437 438 439 440
{
	struct find_symbol_arg fsa;

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

441
	if (each_symbol_section(find_symbol_in_section, &fsa)) {
442 443 444 445
		if (owner)
			*owner = fsa.owner;
		if (crc)
			*crc = fsa.crc;
446
		return fsa.sym;
447 448
	}

449
	pr_debug("Failed to find symbol %s\n", name);
450
	return NULL;
L
Linus Torvalds 已提交
451
}
452
EXPORT_SYMBOL_GPL(find_symbol);
L
Linus Torvalds 已提交
453 454

/* Search for module by name: must hold module_mutex. */
455
static struct module *find_module_all(const char *name, size_t len,
456
				      bool even_unformed)
L
Linus Torvalds 已提交
457 458 459 460
{
	struct module *mod;

	list_for_each_entry(mod, &modules, list) {
461 462
		if (!even_unformed && mod->state == MODULE_STATE_UNFORMED)
			continue;
463
		if (strlen(mod->name) == len && !memcmp(mod->name, name, len))
L
Linus Torvalds 已提交
464 465 466 467
			return mod;
	}
	return NULL;
}
468 469 470

struct module *find_module(const char *name)
{
471
	return find_module_all(name, strlen(name), false);
472
}
473
EXPORT_SYMBOL_GPL(find_module);
L
Linus Torvalds 已提交
474 475

#ifdef CONFIG_SMP
476

477
static inline void __percpu *mod_percpu(struct module *mod)
478
{
479 480
	return mod->percpu;
}
481

482
static int percpu_modalloc(struct module *mod, struct load_info *info)
483
{
484 485 486 487 488 489
	Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu];
	unsigned long align = pcpusec->sh_addralign;

	if (!pcpusec->sh_size)
		return 0;

490
	if (align > PAGE_SIZE) {
491 492
		pr_warn("%s: per-cpu alignment %li > %li\n",
			mod->name, align, PAGE_SIZE);
493 494 495
		align = PAGE_SIZE;
	}

496
	mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align);
497
	if (!mod->percpu) {
498 499
		pr_warn("%s: Could not allocate %lu bytes percpu data\n",
			mod->name, (unsigned long)pcpusec->sh_size);
500 501
		return -ENOMEM;
	}
502
	mod->percpu_size = pcpusec->sh_size;
503
	return 0;
504 505
}

506
static void percpu_modfree(struct module *mod)
507
{
508
	free_percpu(mod->percpu);
509 510
}

511
static unsigned int find_pcpusec(struct load_info *info)
512
{
513
	return find_sec(info, ".data..percpu");
514 515
}

516 517
static void percpu_modcopy(struct module *mod,
			   const void *from, unsigned long size)
518 519 520 521
{
	int cpu;

	for_each_possible_cpu(cpu)
522
		memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
523 524
}

525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541
/**
 * 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) {
542 543
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
544 545 546 547 548 549 550 551 552 553 554 555 556 557 558
		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;
559 560
}

L
Linus Torvalds 已提交
561
#else /* ... !CONFIG_SMP */
562

563
static inline void __percpu *mod_percpu(struct module *mod)
L
Linus Torvalds 已提交
564 565 566
{
	return NULL;
}
567
static int percpu_modalloc(struct module *mod, struct load_info *info)
568
{
569 570 571 572
	/* UP modules shouldn't have this section: ENOMEM isn't quite right */
	if (info->sechdrs[info->index.pcpu].sh_size != 0)
		return -ENOMEM;
	return 0;
573 574
}
static inline void percpu_modfree(struct module *mod)
L
Linus Torvalds 已提交
575 576
{
}
577
static unsigned int find_pcpusec(struct load_info *info)
L
Linus Torvalds 已提交
578 579 580
{
	return 0;
}
581 582
static inline void percpu_modcopy(struct module *mod,
				  const void *from, unsigned long size)
L
Linus Torvalds 已提交
583 584 585 586
{
	/* pcpusec should be 0, and size of that section should be 0. */
	BUG_ON(size != 0);
}
587 588 589 590
bool is_module_percpu_address(unsigned long addr)
{
	return false;
}
591

L
Linus Torvalds 已提交
592 593
#endif /* CONFIG_SMP */

594 595 596 597 598 599
#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,   \
600
			struct module_kobject *mk, char *buffer)      \
601
{                                                                     \
602
	return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field);  \
603 604 605 606 607 608 609
}                                                                     \
static int modinfo_##field##_exists(struct module *mod)               \
{                                                                     \
	return mod->field != NULL;                                    \
}                                                                     \
static void free_modinfo_##field(struct module *mod)                  \
{                                                                     \
610 611
	kfree(mod->field);                                            \
	mod->field = NULL;                                            \
612 613
}                                                                     \
static struct module_attribute modinfo_##field = {                    \
614
	.attr = { .name = __stringify(field), .mode = 0444 },         \
615 616 617 618 619 620 621 622 623
	.show = show_modinfo_##field,                                 \
	.setup = setup_modinfo_##field,                               \
	.test = modinfo_##field##_exists,                             \
	.free = free_modinfo_##field,                                 \
};

MODINFO_ATTR(version);
MODINFO_ATTR(srcversion);

624 625
static char last_unloaded_module[MODULE_NAME_LEN+1];

626
#ifdef CONFIG_MODULE_UNLOAD
627 628 629

EXPORT_TRACEPOINT_SYMBOL(module_get);

630 631 632
/* MODULE_REF_BASE is the base reference count by kmodule loader. */
#define MODULE_REF_BASE	1

L
Linus Torvalds 已提交
633
/* Init the unload section of the module. */
634
static int module_unload_init(struct module *mod)
L
Linus Torvalds 已提交
635
{
636 637 638 639 640 641
	/*
	 * Initialize reference counter to MODULE_REF_BASE.
	 * refcnt == 0 means module is going.
	 */
	atomic_set(&mod->refcnt, MODULE_REF_BASE);

642 643
	INIT_LIST_HEAD(&mod->source_list);
	INIT_LIST_HEAD(&mod->target_list);
644

L
Linus Torvalds 已提交
645
	/* Hold reference count during initialization. */
646
	atomic_inc(&mod->refcnt);
647 648

	return 0;
L
Linus Torvalds 已提交
649 650 651 652 653 654 655
}

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

656 657
	list_for_each_entry(use, &b->source_list, source_list) {
		if (use->source == a) {
658
			pr_debug("%s uses %s!\n", a->name, b->name);
L
Linus Torvalds 已提交
659 660 661
			return 1;
		}
	}
662
	pr_debug("%s does not use %s!\n", a->name, b->name);
L
Linus Torvalds 已提交
663 664 665
	return 0;
}

666 667 668 669 670 671 672 673 674 675 676
/*
 * 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;

677
	pr_debug("Allocating new usage for %s.\n", a->name);
678 679
	use = kmalloc(sizeof(*use), GFP_ATOMIC);
	if (!use) {
680
		pr_warn("%s: out of memory loading\n", a->name);
681 682 683 684 685 686 687 688 689 690
		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;
}

691
/* Module a uses b: caller needs module_mutex() */
692
int ref_module(struct module *a, struct module *b)
L
Linus Torvalds 已提交
693
{
694
	int err;
K
Kay Sievers 已提交
695

696
	if (b == NULL || already_uses(a, b))
697 698
		return 0;

699 700
	/* If module isn't available, we fail. */
	err = strong_try_module_get(b);
701
	if (err)
702
		return err;
L
Linus Torvalds 已提交
703

704 705
	err = add_module_usage(a, b);
	if (err) {
L
Linus Torvalds 已提交
706
		module_put(b);
707
		return err;
L
Linus Torvalds 已提交
708
	}
709
	return 0;
L
Linus Torvalds 已提交
710
}
711
EXPORT_SYMBOL_GPL(ref_module);
L
Linus Torvalds 已提交
712 713 714 715

/* Clear the unload stuff of the module. */
static void module_unload_free(struct module *mod)
{
716
	struct module_use *use, *tmp;
L
Linus Torvalds 已提交
717

718
	mutex_lock(&module_mutex);
719 720
	list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
		struct module *i = use->target;
721
		pr_debug("%s unusing %s\n", mod->name, i->name);
722 723 724 725
		module_put(i);
		list_del(&use->source_list);
		list_del(&use->target_list);
		kfree(use);
L
Linus Torvalds 已提交
726
	}
727
	mutex_unlock(&module_mutex);
L
Linus Torvalds 已提交
728 729 730
}

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

745 746
/* Try to release refcount of module, 0 means success. */
static int try_release_module_ref(struct module *mod)
L
Linus Torvalds 已提交
747
{
748
	int ret;
L
Linus Torvalds 已提交
749

750 751 752 753 754 755
	/* Try to decrement refcnt which we set at loading */
	ret = atomic_sub_return(MODULE_REF_BASE, &mod->refcnt);
	BUG_ON(ret < 0);
	if (ret)
		/* Someone can put this right now, recover with checking */
		ret = atomic_add_unless(&mod->refcnt, MODULE_REF_BASE, 0);
L
Linus Torvalds 已提交
756

757 758 759 760 761
	return ret;
}

static int try_stop_module(struct module *mod, int flags, int *forced)
{
762
	/* If it's not unused, quit unless we're forcing. */
763 764 765
	if (try_release_module_ref(mod) != 0) {
		*forced = try_force_unload(flags);
		if (!(*forced))
L
Linus Torvalds 已提交
766 767 768 769
			return -EWOULDBLOCK;
	}

	/* Mark it as dying. */
770
	mod->state = MODULE_STATE_GOING;
L
Linus Torvalds 已提交
771

772
	return 0;
L
Linus Torvalds 已提交
773 774
}

775
unsigned long module_refcount(struct module *mod)
L
Linus Torvalds 已提交
776
{
777
	return (unsigned long)atomic_read(&mod->refcnt) - MODULE_REF_BASE;
L
Linus Torvalds 已提交
778 779 780 781 782 783
}
EXPORT_SYMBOL(module_refcount);

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

784 785
SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
		unsigned int, flags)
L
Linus Torvalds 已提交
786 787
{
	struct module *mod;
788
	char name[MODULE_NAME_LEN];
L
Linus Torvalds 已提交
789 790
	int ret, forced = 0;

791
	if (!capable(CAP_SYS_MODULE) || modules_disabled)
792 793 794 795 796 797
		return -EPERM;

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

798 799
	if (mutex_lock_interruptible(&module_mutex) != 0)
		return -EINTR;
L
Linus Torvalds 已提交
800 801 802 803 804 805 806

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

807
	if (!list_empty(&mod->source_list)) {
L
Linus Torvalds 已提交
808 809 810 811 812 813 814
		/* 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) {
815
		/* FIXME: if (force), slam module count damn the torpedoes */
816
		pr_debug("%s already dying\n", mod->name);
L
Linus Torvalds 已提交
817 818 819 820 821
		ret = -EBUSY;
		goto out;
	}

	/* If it has an init func, it must have an exit func to unload */
822
	if (mod->init && !mod->exit) {
823
		forced = try_force_unload(flags);
L
Linus Torvalds 已提交
824 825 826 827 828 829 830 831 832 833 834 835
		if (!forced) {
			/* This module can't be removed */
			ret = -EBUSY;
			goto out;
		}
	}

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

836
	mutex_unlock(&module_mutex);
L
Lucas De Marchi 已提交
837
	/* Final destruction now no one is using it. */
838
	if (mod->exit != NULL)
L
Linus Torvalds 已提交
839
		mod->exit();
840 841
	blocking_notifier_call_chain(&module_notify_list,
				     MODULE_STATE_GOING, mod);
842
	async_synchronize_full();
843

844
	/* Store the name of the last unloaded module for diagnostic purposes */
845
	strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
L
Linus Torvalds 已提交
846

847 848 849
	free_module(mod);
	return 0;
out:
850
	mutex_unlock(&module_mutex);
L
Linus Torvalds 已提交
851 852 853
	return ret;
}

854
static inline void print_unload_info(struct seq_file *m, struct module *mod)
L
Linus Torvalds 已提交
855 856 857 858
{
	struct module_use *use;
	int printed_something = 0;

859
	seq_printf(m, " %lu ", module_refcount(mod));
L
Linus Torvalds 已提交
860 861 862

	/* Always include a trailing , so userspace can differentiate
           between this and the old multi-field proc format. */
863
	list_for_each_entry(use, &mod->source_list, source_list) {
L
Linus Torvalds 已提交
864
		printed_something = 1;
865
		seq_printf(m, "%s,", use->source->name);
L
Linus Torvalds 已提交
866 867 868 869 870 871 872 873 874 875 876 877 878 879 880
	}

	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;

881
	preempt_disable();
882
	if (!find_symbol(symbol, &owner, NULL, true, false))
L
Linus Torvalds 已提交
883 884
		BUG();
	module_put(owner);
885
	preempt_enable();
L
Linus Torvalds 已提交
886 887 888
}
EXPORT_SYMBOL(__symbol_put);

889
/* Note this assumes addr is a function, which it currently always is. */
L
Linus Torvalds 已提交
890 891
void symbol_put_addr(void *addr)
{
892
	struct module *modaddr;
893
	unsigned long a = (unsigned long)dereference_function_descriptor(addr);
L
Linus Torvalds 已提交
894

895
	if (core_kernel_text(a))
896
		return;
L
Linus Torvalds 已提交
897

898 899
	/* module_text_address is safe here: we're supposed to have reference
	 * to module from symbol_get, so it can't go away. */
900
	modaddr = __module_text_address(a);
901
	BUG_ON(!modaddr);
902
	module_put(modaddr);
L
Linus Torvalds 已提交
903 904 905 906
}
EXPORT_SYMBOL_GPL(symbol_put_addr);

static ssize_t show_refcnt(struct module_attribute *mattr,
907
			   struct module_kobject *mk, char *buffer)
L
Linus Torvalds 已提交
908
{
909
	return sprintf(buffer, "%lu\n", module_refcount(mk->mod));
L
Linus Torvalds 已提交
910 911
}

912 913
static struct module_attribute modinfo_refcnt =
	__ATTR(refcnt, 0444, show_refcnt, NULL);
L
Linus Torvalds 已提交
914

915 916 917 918
void __module_get(struct module *module)
{
	if (module) {
		preempt_disable();
919
		atomic_inc(&module->refcnt);
920 921 922 923 924 925 926 927 928 929 930 931
		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();
932 933 934
		/* Note: here, we can fail to get a reference */
		if (likely(module_is_live(module) &&
			   atomic_inc_not_zero(&module->refcnt) != 0))
935
			trace_module_get(module, _RET_IP_);
936
		else
937 938 939 940 941 942 943 944
			ret = false;

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

945 946
void module_put(struct module *module)
{
947 948
	int ret;

949
	if (module) {
950
		preempt_disable();
951 952
		ret = atomic_dec_if_positive(&module->refcnt);
		WARN_ON(ret < 0);	/* Failed to put refcount */
953
		trace_module_put(module, _RET_IP_);
954
		preempt_enable();
955 956 957 958
	}
}
EXPORT_SYMBOL(module_put);

L
Linus Torvalds 已提交
959
#else /* !CONFIG_MODULE_UNLOAD */
960
static inline void print_unload_info(struct seq_file *m, struct module *mod)
L
Linus Torvalds 已提交
961 962 963 964 965 966 967 968 969
{
	/* We don't know the usage count, or what modules are using. */
	seq_printf(m, " - -");
}

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

970
int ref_module(struct module *a, struct module *b)
L
Linus Torvalds 已提交
971
{
972
	return strong_try_module_get(b);
L
Linus Torvalds 已提交
973
}
974
EXPORT_SYMBOL_GPL(ref_module);
L
Linus Torvalds 已提交
975

976
static inline int module_unload_init(struct module *mod)
L
Linus Torvalds 已提交
977
{
978
	return 0;
L
Linus Torvalds 已提交
979 980 981
}
#endif /* CONFIG_MODULE_UNLOAD */

982 983 984 985 986 987 988 989 990 991 992 993
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';
994
	if (mod->taints & (1 << TAINT_UNSIGNED_MODULE))
995
		buf[l++] = 'E';
996 997
	/*
	 * TAINT_FORCED_RMMOD: could be added.
998
	 * TAINT_CPU_OUT_OF_SPEC, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't
999 1000 1001 1002 1003
	 * apply to modules.
	 */
	return l;
}

1004
static ssize_t show_initstate(struct module_attribute *mattr,
1005
			      struct module_kobject *mk, char *buffer)
1006 1007 1008
{
	const char *state = "unknown";

1009
	switch (mk->mod->state) {
1010 1011 1012 1013 1014 1015 1016 1017 1018
	case MODULE_STATE_LIVE:
		state = "live";
		break;
	case MODULE_STATE_COMING:
		state = "coming";
		break;
	case MODULE_STATE_GOING:
		state = "going";
		break;
1019 1020
	default:
		BUG();
1021 1022 1023 1024
	}
	return sprintf(buffer, "%s\n", state);
}

1025 1026
static struct module_attribute modinfo_initstate =
	__ATTR(initstate, 0444, show_initstate, NULL);
1027

1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038
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;
}

1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071
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);
1072

1073
static struct module_attribute *modinfo_attrs[] = {
1074
	&module_uevent,
1075 1076
	&modinfo_version,
	&modinfo_srcversion,
1077 1078 1079 1080
	&modinfo_initstate,
	&modinfo_coresize,
	&modinfo_initsize,
	&modinfo_taint,
1081
#ifdef CONFIG_MODULE_UNLOAD
1082
	&modinfo_refcnt,
1083 1084 1085 1086
#endif
	NULL,
};

L
Linus Torvalds 已提交
1087 1088
static const char vermagic[] = VERMAGIC_STRING;

1089
static int try_to_force_load(struct module *mod, const char *reason)
1090 1091
{
#ifdef CONFIG_MODULE_FORCE_LOAD
1092
	if (!test_taint(TAINT_FORCED_MODULE))
1093
		pr_warn("%s: %s: kernel tainted.\n", mod->name, reason);
1094
	add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
1095 1096 1097 1098 1099 1100
	return 0;
#else
	return -ENOEXEC;
#endif
}

L
Linus Torvalds 已提交
1101
#ifdef CONFIG_MODVERSIONS
1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112
/* 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
1113 1114 1115 1116
static int check_version(Elf_Shdr *sechdrs,
			 unsigned int versindex,
			 const char *symname,
			 struct module *mod, 
1117 1118
			 const unsigned long *crc,
			 const struct module *crc_owner)
L
Linus Torvalds 已提交
1119 1120 1121 1122 1123 1124 1125 1126
{
	unsigned int i, num_versions;
	struct modversion_info *versions;

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

1127 1128 1129 1130
	/* 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
1131 1132 1133 1134 1135 1136 1137 1138
	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;

1139
		if (versions[i].crc == maybe_relocated(*crc, crc_owner))
L
Linus Torvalds 已提交
1140
			return 1;
1141
		pr_debug("Found checksum %lX vs module %lX\n",
1142
		       maybe_relocated(*crc, crc_owner), versions[i].crc);
1143
		goto bad_version;
L
Linus Torvalds 已提交
1144
	}
1145

1146
	pr_warn("%s: no symbol version for %s\n", mod->name, symname);
1147
	return 0;
1148 1149 1150 1151 1152

bad_version:
	printk("%s: disagrees about version of symbol %s\n",
	       mod->name, symname);
	return 0;
L
Linus Torvalds 已提交
1153 1154 1155 1156 1157 1158 1159 1160
}

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

1161 1162
	/* Since this should be found in kernel (which can't be removed),
	 * no locking is necessary. */
1163
	if (!find_symbol(VMLINUX_SYMBOL_STR(module_layout), NULL,
1164
			 &crc, true, false))
L
Linus Torvalds 已提交
1165
		BUG();
1166 1167
	return check_version(sechdrs, versindex,
			     VMLINUX_SYMBOL_STR(module_layout), mod, crc,
1168
			     NULL);
L
Linus Torvalds 已提交
1169 1170
}

1171 1172 1173
/* 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
1174
{
1175 1176 1177 1178
	if (has_crcs) {
		amagic += strcspn(amagic, " ");
		bmagic += strcspn(bmagic, " ");
	}
L
Linus Torvalds 已提交
1179 1180 1181 1182 1183 1184 1185
	return strcmp(amagic, bmagic) == 0;
}
#else
static inline int check_version(Elf_Shdr *sechdrs,
				unsigned int versindex,
				const char *symname,
				struct module *mod, 
1186 1187
				const unsigned long *crc,
				const struct module *crc_owner)
L
Linus Torvalds 已提交
1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198
{
	return 1;
}

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

1199 1200
static inline int same_magic(const char *amagic, const char *bmagic,
			     bool has_crcs)
L
Linus Torvalds 已提交
1201 1202 1203 1204 1205
{
	return strcmp(amagic, bmagic) == 0;
}
#endif /* CONFIG_MODVERSIONS */

1206
/* Resolve a symbol for this module.  I.e. if we find one, record usage. */
1207 1208
static const struct kernel_symbol *resolve_symbol(struct module *mod,
						  const struct load_info *info,
1209
						  const char *name,
1210
						  char ownername[])
L
Linus Torvalds 已提交
1211 1212
{
	struct module *owner;
1213
	const struct kernel_symbol *sym;
L
Linus Torvalds 已提交
1214
	const unsigned long *crc;
1215
	int err;
L
Linus Torvalds 已提交
1216

1217
	mutex_lock(&module_mutex);
1218
	sym = find_symbol(name, &owner, &crc,
1219
			  !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
1220 1221 1222
	if (!sym)
		goto unlock;

1223 1224
	if (!check_version(info->sechdrs, info->index.vers, name, mod, crc,
			   owner)) {
1225 1226
		sym = ERR_PTR(-EINVAL);
		goto getname;
L
Linus Torvalds 已提交
1227
	}
1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238

	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:
1239
	mutex_unlock(&module_mutex);
1240
	return sym;
L
Linus Torvalds 已提交
1241 1242
}

1243 1244 1245 1246
static const struct kernel_symbol *
resolve_symbol_wait(struct module *mod,
		    const struct load_info *info,
		    const char *name)
1247 1248
{
	const struct kernel_symbol *ksym;
1249
	char owner[MODULE_NAME_LEN];
1250 1251

	if (wait_event_interruptible_timeout(module_wq,
1252 1253
			!IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
			|| PTR_ERR(ksym) != -EBUSY,
1254
					     30 * HZ) <= 0) {
1255 1256
		pr_warn("%s: gave up waiting for init of module %s.\n",
			mod->name, owner);
1257 1258 1259 1260
	}
	return ksym;
}

L
Linus Torvalds 已提交
1261 1262 1263 1264
/*
 * /sys/module/foo/sections stuff
 * J. Corbet <corbet@lwn.net>
 */
R
Rusty Russell 已提交
1265
#ifdef CONFIG_SYSFS
1266

R
Rusty Russell 已提交
1267
#ifdef CONFIG_KALLSYMS
1268 1269 1270 1271 1272
static inline bool sect_empty(const Elf_Shdr *sect)
{
	return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
}

1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286
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
1287
static ssize_t module_sect_show(struct module_attribute *mattr,
1288
				struct module_kobject *mk, char *buf)
L
Linus Torvalds 已提交
1289 1290 1291
{
	struct module_sect_attr *sattr =
		container_of(mattr, struct module_sect_attr, mattr);
1292
	return sprintf(buf, "0x%pK\n", (void *)sattr->address);
L
Linus Torvalds 已提交
1293 1294
}

1295 1296
static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
{
1297
	unsigned int section;
1298 1299 1300 1301 1302 1303

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

R
Rusty Russell 已提交
1304
static void add_sect_attrs(struct module *mod, const struct load_info *info)
L
Linus Torvalds 已提交
1305 1306 1307 1308 1309
{
	unsigned int nloaded = 0, i, size[2];
	struct module_sect_attrs *sect_attrs;
	struct module_sect_attr *sattr;
	struct attribute **gattr;
1310

L
Linus Torvalds 已提交
1311
	/* Count loaded sections and allocate structures */
R
Rusty Russell 已提交
1312 1313
	for (i = 0; i < info->hdr->e_shnum; i++)
		if (!sect_empty(&info->sechdrs[i]))
L
Linus Torvalds 已提交
1314 1315 1316 1317 1318
			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]);
1319 1320
	sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
	if (sect_attrs == NULL)
L
Linus Torvalds 已提交
1321 1322 1323 1324 1325 1326
		return;

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

1327
	sect_attrs->nsections = 0;
L
Linus Torvalds 已提交
1328 1329
	sattr = &sect_attrs->attrs[0];
	gattr = &sect_attrs->grp.attrs[0];
R
Rusty Russell 已提交
1330 1331 1332
	for (i = 0; i < info->hdr->e_shnum; i++) {
		Elf_Shdr *sec = &info->sechdrs[i];
		if (sect_empty(sec))
1333
			continue;
R
Rusty Russell 已提交
1334 1335
		sattr->address = sec->sh_addr;
		sattr->name = kstrdup(info->secstrings + sec->sh_name,
1336 1337 1338 1339
					GFP_KERNEL);
		if (sattr->name == NULL)
			goto out;
		sect_attrs->nsections++;
1340
		sysfs_attr_init(&sattr->mattr.attr);
L
Linus Torvalds 已提交
1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354
		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:
1355
	free_sect_attrs(sect_attrs);
L
Linus Torvalds 已提交
1356 1357 1358 1359 1360 1361 1362 1363 1364
}

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. */
1365
		free_sect_attrs(mod->sect_attrs);
L
Linus Torvalds 已提交
1366 1367 1368 1369
		mod->sect_attrs = NULL;
	}
}

1370 1371 1372 1373 1374 1375 1376 1377 1378 1379
/*
 * /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];
};

1380
static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397
				 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]);
1398
		kobject_put(notes_attrs->dir);
1399 1400 1401 1402
	}
	kfree(notes_attrs);
}

R
Rusty Russell 已提交
1403
static void add_notes_attrs(struct module *mod, const struct load_info *info)
1404 1405 1406 1407 1408
{
	unsigned int notes, loaded, i;
	struct module_notes_attrs *notes_attrs;
	struct bin_attribute *nattr;

1409 1410 1411 1412
	/* failed to create section attributes, so can't create notes */
	if (!mod->sect_attrs)
		return;

1413 1414
	/* Count notes sections and allocate structures.  */
	notes = 0;
R
Rusty Russell 已提交
1415 1416 1417
	for (i = 0; i < info->hdr->e_shnum; i++)
		if (!sect_empty(&info->sechdrs[i]) &&
		    (info->sechdrs[i].sh_type == SHT_NOTE))
1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430
			++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
1431 1432
	for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
		if (sect_empty(&info->sechdrs[i]))
1433
			continue;
R
Rusty Russell 已提交
1434
		if (info->sechdrs[i].sh_type == SHT_NOTE) {
1435
			sysfs_bin_attr_init(nattr);
1436 1437
			nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
			nattr->attr.mode = S_IRUGO;
R
Rusty Russell 已提交
1438 1439
			nattr->size = info->sechdrs[i].sh_size;
			nattr->private = (void *) info->sechdrs[i].sh_addr;
1440 1441 1442 1443 1444 1445
			nattr->read = module_notes_read;
			++nattr;
		}
		++loaded;
	}

1446
	notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467
	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
1468
#else
1469

R
Rusty Russell 已提交
1470 1471
static inline void add_sect_attrs(struct module *mod,
				  const struct load_info *info)
L
Linus Torvalds 已提交
1472 1473 1474 1475 1476 1477
{
}

static inline void remove_sect_attrs(struct module *mod)
{
}
1478

R
Rusty Russell 已提交
1479 1480
static inline void add_notes_attrs(struct module *mod,
				   const struct load_info *info)
1481 1482 1483 1484 1485 1486
{
}

static inline void remove_notes_attrs(struct module *mod)
{
}
R
Rusty Russell 已提交
1487
#endif /* CONFIG_KALLSYMS */
L
Linus Torvalds 已提交
1488

1489 1490 1491 1492 1493 1494
static void add_usage_links(struct module *mod)
{
#ifdef CONFIG_MODULE_UNLOAD
	struct module_use *use;
	int nowarn;

1495
	mutex_lock(&module_mutex);
1496 1497 1498 1499
	list_for_each_entry(use, &mod->target_list, target_list) {
		nowarn = sysfs_create_link(use->target->holders_dir,
					   &mod->mkobj.kobj, mod->name);
	}
1500
	mutex_unlock(&module_mutex);
1501 1502 1503 1504 1505 1506 1507 1508
#endif
}

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

1509
	mutex_lock(&module_mutex);
1510 1511
	list_for_each_entry(use, &mod->target_list, target_list)
		sysfs_remove_link(use->target->holders_dir, mod->name);
1512
	mutex_unlock(&module_mutex);
1513 1514 1515
#endif
}

1516
static int module_add_modinfo_attrs(struct module *mod)
1517 1518
{
	struct module_attribute *attr;
1519
	struct module_attribute *temp_attr;
1520 1521 1522
	int error = 0;
	int i;

1523 1524 1525 1526 1527 1528 1529
	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;
1530 1531
	for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
		if (!attr->test ||
1532 1533
		    (attr->test && attr->test(mod))) {
			memcpy(temp_attr, attr, sizeof(*temp_attr));
1534
			sysfs_attr_init(&temp_attr->attr);
1535 1536 1537
			error = sysfs_create_file(&mod->mkobj.kobj,&temp_attr->attr);
			++temp_attr;
		}
1538 1539 1540 1541
	}
	return error;
}

1542
static void module_remove_modinfo_attrs(struct module *mod)
1543 1544 1545 1546
{
	struct module_attribute *attr;
	int i;

1547 1548 1549 1550
	for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
		/* pick a field to test for end of list */
		if (!attr->attr.name)
			break;
1551
		sysfs_remove_file(&mod->mkobj.kobj,&attr->attr);
1552 1553
		if (attr->free)
			attr->free(mod);
1554
	}
1555
	kfree(mod->modinfo_attrs);
1556
}
L
Linus Torvalds 已提交
1557

1558 1559 1560 1561 1562 1563 1564 1565
static void mod_kobject_put(struct module *mod)
{
	DECLARE_COMPLETION_ONSTACK(c);
	mod->mkobj.kobj_completion = &c;
	kobject_put(&mod->mkobj.kobj);
	wait_for_completion(&c);
}

1566
static int mod_sysfs_init(struct module *mod)
L
Linus Torvalds 已提交
1567 1568
{
	int err;
1569
	struct kobject *kobj;
L
Linus Torvalds 已提交
1570

1571
	if (!module_sysfs_initialized) {
1572
		pr_err("%s: module sysfs not initialized\n", mod->name);
1573 1574 1575
		err = -EINVAL;
		goto out;
	}
1576 1577 1578

	kobj = kset_find_obj(module_kset, mod->name);
	if (kobj) {
1579
		pr_err("%s: module is already loaded\n", mod->name);
1580 1581 1582 1583 1584
		kobject_put(kobj);
		err = -EINVAL;
		goto out;
	}

L
Linus Torvalds 已提交
1585
	mod->mkobj.mod = mod;
1586

1587 1588 1589 1590 1591
	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)
1592
		mod_kobject_put(mod);
K
Kay Sievers 已提交
1593

1594
	/* delay uevent until full sysfs population */
K
Kay Sievers 已提交
1595 1596 1597 1598
out:
	return err;
}

1599
static int mod_sysfs_setup(struct module *mod,
R
Rusty Russell 已提交
1600
			   const struct load_info *info,
K
Kay Sievers 已提交
1601 1602 1603 1604 1605
			   struct kernel_param *kparam,
			   unsigned int num_params)
{
	int err;

1606 1607 1608 1609
	err = mod_sysfs_init(mod);
	if (err)
		goto out;

1610
	mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1611 1612
	if (!mod->holders_dir) {
		err = -ENOMEM;
K
Kay Sievers 已提交
1613
		goto out_unreg;
1614
	}
K
Kay Sievers 已提交
1615

L
Linus Torvalds 已提交
1616 1617
	err = module_param_sysfs_setup(mod, kparam, num_params);
	if (err)
K
Kay Sievers 已提交
1618
		goto out_unreg_holders;
L
Linus Torvalds 已提交
1619

1620 1621
	err = module_add_modinfo_attrs(mod);
	if (err)
1622
		goto out_unreg_param;
1623

1624
	add_usage_links(mod);
R
Rusty Russell 已提交
1625 1626
	add_sect_attrs(mod, info);
	add_notes_attrs(mod, info);
1627

1628
	kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
L
Linus Torvalds 已提交
1629 1630
	return 0;

1631 1632
out_unreg_param:
	module_param_sysfs_remove(mod);
K
Kay Sievers 已提交
1633
out_unreg_holders:
1634
	kobject_put(mod->holders_dir);
K
Kay Sievers 已提交
1635
out_unreg:
1636
	mod_kobject_put(mod);
1637
out:
L
Linus Torvalds 已提交
1638 1639
	return err;
}
1640 1641 1642

static void mod_sysfs_fini(struct module *mod)
{
R
Rusty Russell 已提交
1643 1644
	remove_notes_attrs(mod);
	remove_sect_attrs(mod);
1645
	mod_kobject_put(mod);
1646 1647
}

R
Rusty Russell 已提交
1648
#else /* !CONFIG_SYSFS */
1649

R
Rusty Russell 已提交
1650 1651
static int mod_sysfs_setup(struct module *mod,
			   const struct load_info *info,
1652 1653 1654 1655 1656 1657
			   struct kernel_param *kparam,
			   unsigned int num_params)
{
	return 0;
}

1658 1659 1660 1661
static void mod_sysfs_fini(struct module *mod)
{
}

1662 1663 1664 1665
static void module_remove_modinfo_attrs(struct module *mod)
{
}

1666 1667 1668 1669
static void del_usage_links(struct module *mod)
{
}

1670
#endif /* CONFIG_SYSFS */
L
Linus Torvalds 已提交
1671

1672
static void mod_sysfs_teardown(struct module *mod)
L
Linus Torvalds 已提交
1673
{
1674
	del_usage_links(mod);
1675
	module_remove_modinfo_attrs(mod);
L
Linus Torvalds 已提交
1676
	module_param_sysfs_remove(mod);
1677 1678
	kobject_put(mod->mkobj.drivers_dir);
	kobject_put(mod->holders_dir);
1679
	mod_sysfs_fini(mod);
L
Linus Torvalds 已提交
1680 1681
}

1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725
#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);
	}
}

1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743
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);
1744 1745 1746
}

/* Iterate through all modules and set each module's text as RW */
1747
void set_all_modules_text_rw(void)
1748 1749 1750 1751 1752
{
	struct module *mod;

	mutex_lock(&module_mutex);
	list_for_each_entry_rcu(mod, &modules, list) {
1753 1754
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766 1767 1768 1769
		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 */
1770
void set_all_modules_text_ro(void)
1771 1772 1773 1774 1775
{
	struct module *mod;

	mutex_lock(&module_mutex);
	list_for_each_entry_rcu(mod, &modules, list) {
1776 1777
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
1778 1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789 1790 1791 1792
		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) { }
1793 1794
static void unset_module_core_ro_nx(struct module *mod) { }
static void unset_module_init_ro_nx(struct module *mod) { }
1795 1796
#endif

1797 1798 1799 1800 1801 1802 1803 1804 1805
void __weak module_free(struct module *mod, void *module_region)
{
	vfree(module_region);
}

void __weak module_arch_cleanup(struct module *mod)
{
}

1806
/* Free a module, remove from lists, etc. */
L
Linus Torvalds 已提交
1807 1808
static void free_module(struct module *mod)
{
1809 1810
	trace_module_free(mod);

1811
	mod_sysfs_teardown(mod);
L
Linus Torvalds 已提交
1812

1813 1814
	/* We leave it in list to prevent duplicate loads, but make sure
	 * that noone uses it while it's being deconstructed. */
1815
	mutex_lock(&module_mutex);
1816
	mod->state = MODULE_STATE_UNFORMED;
1817
	mutex_unlock(&module_mutex);
1818

1819 1820 1821
	/* Remove dynamic debug info */
	ddebug_remove_module(mod->name);

L
Linus Torvalds 已提交
1822 1823 1824 1825 1826 1827
	/* Arch-specific cleanup. */
	module_arch_cleanup(mod);

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

1828 1829 1830
	/* Free any allocated parameters. */
	destroy_params(mod->kp, mod->num_kp);

1831 1832
	/* Now we can delete it from the lists */
	mutex_lock(&module_mutex);
1833 1834
	/* Unlink carefully: kallsyms could be walking list. */
	list_del_rcu(&mod->list);
1835
	/* Remove this module from bug list, this uses list_del_rcu */
1836
	module_bug_cleanup(mod);
1837 1838
	/* Wait for RCU synchronizing before releasing mod->list and buglist. */
	synchronize_rcu();
1839 1840
	mutex_unlock(&module_mutex);

L
Linus Torvalds 已提交
1841
	/* This may be NULL, but that's OK */
1842
	unset_module_init_ro_nx(mod);
L
Linus Torvalds 已提交
1843 1844
	module_free(mod, mod->module_init);
	kfree(mod->args);
1845
	percpu_modfree(mod);
1846

I
Ingo Molnar 已提交
1847 1848 1849
	/* Free lock-classes: */
	lockdep_free_key_range(mod->module_core, mod->core_size);

L
Linus Torvalds 已提交
1850
	/* Finally, free the core (containing the module structure) */
1851
	unset_module_core_ro_nx(mod);
L
Linus Torvalds 已提交
1852
	module_free(mod, mod->module_core);
1853 1854 1855 1856

#ifdef CONFIG_MPU
	update_protections(current->mm);
#endif
L
Linus Torvalds 已提交
1857 1858 1859 1860 1861
}

void *__symbol_get(const char *symbol)
{
	struct module *owner;
1862
	const struct kernel_symbol *sym;
L
Linus Torvalds 已提交
1863

1864
	preempt_disable();
1865 1866 1867
	sym = find_symbol(symbol, &owner, NULL, true, true);
	if (sym && strong_try_module_get(owner))
		sym = NULL;
1868
	preempt_enable();
L
Linus Torvalds 已提交
1869

1870
	return sym ? (void *)sym->value : NULL;
L
Linus Torvalds 已提交
1871 1872 1873
}
EXPORT_SYMBOL_GPL(__symbol_get);

1874 1875
/*
 * Ensure that an exported symbol [global namespace] does not already exist
1876
 * in the kernel or in some other module's exported symbol table.
1877 1878
 *
 * You must hold the module_mutex.
1879 1880 1881
 */
static int verify_export_symbols(struct module *mod)
{
1882
	unsigned int i;
1883
	struct module *owner;
1884 1885 1886 1887 1888 1889 1890 1891
	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 },
1892
#ifdef CONFIG_UNUSED_SYMBOLS
1893 1894
		{ mod->unused_syms, mod->num_unused_syms },
		{ mod->unused_gpl_syms, mod->num_unused_gpl_syms },
1895
#endif
1896
	};
1897

1898 1899
	for (i = 0; i < ARRAY_SIZE(arr); i++) {
		for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
1900
			if (find_symbol(s->name, &owner, NULL, true, false)) {
1901
				pr_err("%s: exports duplicate symbol %s"
1902 1903 1904 1905
				       " (owned by %s)\n",
				       mod->name, s->name, module_name(owner));
				return -ENOEXEC;
			}
1906
		}
1907 1908
	}
	return 0;
1909 1910
}

1911
/* Change all symbols so that st_value encodes the pointer directly. */
1912 1913 1914 1915
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
1916
	unsigned long secbase;
1917
	unsigned int i;
L
Linus Torvalds 已提交
1918
	int ret = 0;
1919
	const struct kernel_symbol *ksym;
L
Linus Torvalds 已提交
1920

1921 1922 1923
	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
1924 1925
		switch (sym[i].st_shndx) {
		case SHN_COMMON:
1926 1927 1928 1929
			/* Ignore common symbols */
			if (!strncmp(name, "__gnu_lto", 9))
				break;

L
Linus Torvalds 已提交
1930 1931
			/* We compiled with -fno-common.  These are not
			   supposed to happen.  */
1932
			pr_debug("Common symbol: %s\n", name);
L
Linus Torvalds 已提交
1933 1934 1935 1936 1937 1938 1939
			printk("%s: please compile with -fno-common\n",
			       mod->name);
			ret = -ENOEXEC;
			break;

		case SHN_ABS:
			/* Don't need to do anything */
1940
			pr_debug("Absolute symbol: 0x%08lx\n",
L
Linus Torvalds 已提交
1941 1942 1943 1944
			       (long)sym[i].st_value);
			break;

		case SHN_UNDEF:
1945
			ksym = resolve_symbol_wait(mod, info, name);
L
Linus Torvalds 已提交
1946
			/* Ok if resolved.  */
1947
			if (ksym && !IS_ERR(ksym)) {
1948
				sym[i].st_value = ksym->value;
L
Linus Torvalds 已提交
1949
				break;
1950 1951
			}

L
Linus Torvalds 已提交
1952
			/* Ok if weak.  */
1953
			if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
L
Linus Torvalds 已提交
1954 1955
				break;

1956 1957
			pr_warn("%s: Unknown symbol %s (err %li)\n",
				mod->name, name, PTR_ERR(ksym));
1958
			ret = PTR_ERR(ksym) ?: -ENOENT;
L
Linus Torvalds 已提交
1959 1960 1961 1962
			break;

		default:
			/* Divert to percpu allocation if a percpu var. */
1963
			if (sym[i].st_shndx == info->index.pcpu)
1964
				secbase = (unsigned long)mod_percpu(mod);
L
Linus Torvalds 已提交
1965
			else
1966
				secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
L
Linus Torvalds 已提交
1967 1968 1969 1970 1971 1972 1973 1974
			sym[i].st_value += secbase;
			break;
		}
	}

	return ret;
}

1975
static int apply_relocations(struct module *mod, const struct load_info *info)
1976 1977 1978 1979 1980
{
	unsigned int i;
	int err = 0;

	/* Now do relocations. */
1981 1982
	for (i = 1; i < info->hdr->e_shnum; i++) {
		unsigned int infosec = info->sechdrs[i].sh_info;
1983 1984

		/* Not a valid relocation section? */
1985
		if (infosec >= info->hdr->e_shnum)
1986 1987 1988
			continue;

		/* Don't bother with non-allocated sections */
1989
		if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
1990 1991
			continue;

1992 1993 1994 1995 1996 1997
		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);
1998 1999 2000 2001 2002 2003
		if (err < 0)
			break;
	}
	return err;
}

2004 2005 2006 2007 2008 2009 2010 2011
/* 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
2012
/* Update size with this section: return offset. */
2013 2014
static long get_offset(struct module *mod, unsigned int *size,
		       Elf_Shdr *sechdr, unsigned int section)
L
Linus Torvalds 已提交
2015 2016 2017
{
	long ret;

2018
	*size += arch_mod_section_prepend(mod, section);
L
Linus Torvalds 已提交
2019 2020 2021 2022 2023 2024 2025 2026 2027
	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. */
2028
static void layout_sections(struct module *mod, struct load_info *info)
L
Linus Torvalds 已提交
2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040
{
	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;

2041 2042
	for (i = 0; i < info->hdr->e_shnum; i++)
		info->sechdrs[i].sh_entsize = ~0UL;
L
Linus Torvalds 已提交
2043

2044
	pr_debug("Core section allocation order:\n");
L
Linus Torvalds 已提交
2045
	for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2046 2047 2048
		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
2049 2050 2051 2052

			if ((s->sh_flags & masks[m][0]) != masks[m][0]
			    || (s->sh_flags & masks[m][1])
			    || s->sh_entsize != ~0UL
2053
			    || strstarts(sname, ".init"))
L
Linus Torvalds 已提交
2054
				continue;
2055
			s->sh_entsize = get_offset(mod, &mod->core_size, s, i);
2056
			pr_debug("\t%s\n", sname);
L
Linus Torvalds 已提交
2057
		}
2058 2059 2060
		switch (m) {
		case 0: /* executable */
			mod->core_size = debug_align(mod->core_size);
L
Linus Torvalds 已提交
2061
			mod->core_text_size = mod->core_size;
2062 2063 2064 2065 2066 2067 2068 2069 2070
			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
2071 2072
	}

2073
	pr_debug("Init section allocation order:\n");
L
Linus Torvalds 已提交
2074
	for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2075 2076 2077
		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
2078 2079 2080 2081

			if ((s->sh_flags & masks[m][0]) != masks[m][0]
			    || (s->sh_flags & masks[m][1])
			    || s->sh_entsize != ~0UL
2082
			    || !strstarts(sname, ".init"))
L
Linus Torvalds 已提交
2083
				continue;
2084
			s->sh_entsize = (get_offset(mod, &mod->init_size, s, i)
L
Linus Torvalds 已提交
2085
					 | INIT_OFFSET_MASK);
2086
			pr_debug("\t%s\n", sname);
L
Linus Torvalds 已提交
2087
		}
2088 2089 2090
		switch (m) {
		case 0: /* executable */
			mod->init_size = debug_align(mod->init_size);
L
Linus Torvalds 已提交
2091
			mod->init_text_size = mod->init_size;
2092 2093 2094 2095 2096 2097 2098 2099 2100
			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
2101 2102 2103 2104 2105 2106 2107 2108
	}
}

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

2109
	if (!license_is_gpl_compatible(license)) {
2110
		if (!test_taint(TAINT_PROPRIETARY_MODULE))
2111 2112
			pr_warn("%s: module license '%s' taints kernel.\n",
				mod->name, license);
2113 2114
		add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
				 LOCKDEP_NOW_UNRELIABLE);
L
Linus Torvalds 已提交
2115 2116 2117 2118 2119 2120 2121 2122 2123 2124 2125 2126 2127 2128 2129 2130 2131 2132 2133 2134 2135 2136
	}
}

/* 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;
}

2137
static char *get_modinfo(struct load_info *info, const char *tag)
L
Linus Torvalds 已提交
2138 2139 2140
{
	char *p;
	unsigned int taglen = strlen(tag);
2141 2142
	Elf_Shdr *infosec = &info->sechdrs[info->index.info];
	unsigned long size = infosec->sh_size;
L
Linus Torvalds 已提交
2143

2144
	for (p = (char *)infosec->sh_addr; p; p = next_string(p, &size)) {
L
Linus Torvalds 已提交
2145 2146 2147 2148 2149 2150
		if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
			return p + taglen + 1;
	}
	return NULL;
}

2151
static void setup_modinfo(struct module *mod, struct load_info *info)
2152 2153 2154 2155 2156 2157
{
	struct module_attribute *attr;
	int i;

	for (i = 0; (attr = modinfo_attrs[i]); i++) {
		if (attr->setup)
2158
			attr->setup(mod, get_modinfo(info, attr->attr.name));
2159 2160 2161
	}
}

2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 2172
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
2173
#ifdef CONFIG_KALLSYMS
2174 2175 2176 2177 2178 2179

/* 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)
{
2180 2181
	return bsearch(name, start, stop - start,
			sizeof(struct kernel_symbol), cmp_name);
2182 2183
}

2184 2185
static int is_exported(const char *name, unsigned long value,
		       const struct module *mod)
L
Linus Torvalds 已提交
2186
{
2187 2188 2189
	const struct kernel_symbol *ks;
	if (!mod)
		ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
2190
	else
2191 2192
		ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
	return ks != NULL && ks->value == value;
L
Linus Torvalds 已提交
2193 2194 2195
}

/* As per nm */
2196
static char elf_type(const Elf_Sym *sym, const struct load_info *info)
L
Linus Torvalds 已提交
2197
{
2198 2199
	const Elf_Shdr *sechdrs = info->sechdrs;

L
Linus Torvalds 已提交
2200 2201 2202 2203 2204 2205 2206 2207 2208 2209 2210 2211 2212 2213 2214 2215 2216 2217 2218 2219 2220 2221 2222 2223 2224 2225 2226 2227 2228
	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';
	}
2229 2230
	if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
		      ".debug")) {
L
Linus Torvalds 已提交
2231
		return 'n';
2232
	}
L
Linus Torvalds 已提交
2233 2234 2235
	return '?';
}

2236 2237 2238 2239 2240 2241 2242 2243 2244 2245 2246 2247 2248 2249 2250 2251 2252 2253 2254 2255 2256
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;
}

2257 2258 2259 2260 2261 2262 2263
/*
 * 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>.
 */
2264
static void layout_symtab(struct module *mod, struct load_info *info)
2265
{
2266 2267
	Elf_Shdr *symsect = info->sechdrs + info->index.sym;
	Elf_Shdr *strsect = info->sechdrs + info->index.str;
2268
	const Elf_Sym *src;
2269
	unsigned int i, nsrc, ndst, strtab_size = 0;
2270 2271 2272 2273

	/* 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,
2274
					 info->index.sym) | INIT_OFFSET_MASK;
2275
	pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
2276

2277
	src = (void *)info->hdr + symsect->sh_offset;
2278
	nsrc = symsect->sh_size / sizeof(*src);
2279

2280
	/* Compute total space required for the core symbols' strtab. */
2281 2282 2283 2284
	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;
2285
			ndst++;
2286
		}
2287
	}
2288 2289

	/* Append room for core symbols at end of core part. */
2290
	info->symoffs = ALIGN(mod->core_size, symsect->sh_addralign ?: 1);
2291 2292
	info->stroffs = mod->core_size = info->symoffs + ndst * sizeof(Elf_Sym);
	mod->core_size += strtab_size;
2293

2294 2295 2296
	/* 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,
2297
					 info->index.str) | INIT_OFFSET_MASK;
2298
	pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
2299 2300
}

2301
static void add_kallsyms(struct module *mod, const struct load_info *info)
L
Linus Torvalds 已提交
2302
{
2303 2304 2305
	unsigned int i, ndst;
	const Elf_Sym *src;
	Elf_Sym *dst;
2306
	char *s;
2307
	Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
L
Linus Torvalds 已提交
2308

2309 2310
	mod->symtab = (void *)symsec->sh_addr;
	mod->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
2311 2312
	/* 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
2313 2314 2315

	/* Set types up while we still have access to sections. */
	for (i = 0; i < mod->num_symtab; i++)
2316
		mod->symtab[i].st_info = elf_type(&mod->symtab[i], info);
2317

2318
	mod->core_symtab = dst = mod->module_core + info->symoffs;
2319
	mod->core_strtab = s = mod->module_core + info->stroffs;
2320
	src = mod->symtab;
2321 2322 2323 2324 2325 2326 2327 2328
	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;
		}
2329 2330
	}
	mod->core_num_syms = ndst;
L
Linus Torvalds 已提交
2331 2332
}
#else
2333
static inline void layout_symtab(struct module *mod, struct load_info *info)
2334 2335
{
}
2336

2337
static void add_kallsyms(struct module *mod, const struct load_info *info)
L
Linus Torvalds 已提交
2338 2339 2340 2341
{
}
#endif /* CONFIG_KALLSYMS */

2342
static void dynamic_debug_setup(struct _ddebug *debug, unsigned int num)
2343
{
2344 2345
	if (!debug)
		return;
2346 2347
#ifdef CONFIG_DYNAMIC_DEBUG
	if (ddebug_add_module(debug, num, debug->modname))
2348 2349
		pr_err("dynamic debug error adding module: %s\n",
			debug->modname);
2350
#endif
2351
}
2352

2353 2354 2355 2356 2357 2358
static void dynamic_debug_remove(struct _ddebug *debug)
{
	if (debug)
		ddebug_remove_module(debug->modname);
}

2359 2360
void * __weak module_alloc(unsigned long size)
{
2361
	return vmalloc_exec(size);
2362 2363
}

2364 2365 2366 2367 2368
static void *module_alloc_update_bounds(unsigned long size)
{
	void *ret = module_alloc(size);

	if (ret) {
2369
		mutex_lock(&module_mutex);
2370 2371 2372 2373 2374
		/* 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;
2375
		mutex_unlock(&module_mutex);
2376 2377 2378 2379
	}
	return ret;
}

2380
#ifdef CONFIG_DEBUG_KMEMLEAK
2381 2382
static void kmemleak_load_module(const struct module *mod,
				 const struct load_info *info)
2383 2384 2385 2386
{
	unsigned int i;

	/* only scan the sections containing data */
2387
	kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
2388

2389
	for (i = 1; i < info->hdr->e_shnum; i++) {
2390 2391 2392 2393
		/* Scan all writable sections that's not executable */
		if (!(info->sechdrs[i].sh_flags & SHF_ALLOC) ||
		    !(info->sechdrs[i].sh_flags & SHF_WRITE) ||
		    (info->sechdrs[i].sh_flags & SHF_EXECINSTR))
2394 2395
			continue;

2396 2397
		kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
				   info->sechdrs[i].sh_size, GFP_KERNEL);
2398 2399 2400
	}
}
#else
2401 2402
static inline void kmemleak_load_module(const struct module *mod,
					const struct load_info *info)
2403 2404 2405 2406
{
}
#endif

2407
#ifdef CONFIG_MODULE_SIG
2408
static int module_sig_check(struct load_info *info)
2409 2410
{
	int err = -ENOKEY;
2411 2412
	const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
	const void *mod = info->hdr;
2413

2414 2415
	if (info->len > markerlen &&
	    memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
2416
		/* We truncate the module to discard the signature */
2417 2418
		info->len -= markerlen;
		err = mod_verify_sig(mod, &info->len);
2419 2420 2421 2422 2423 2424 2425 2426 2427 2428 2429 2430 2431 2432
	}

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

	/* Not having a signature is only an error if we're strict. */
	if (err == -ENOKEY && !sig_enforce)
		err = 0;

	return err;
}
#else /* !CONFIG_MODULE_SIG */
2433
static int module_sig_check(struct load_info *info)
2434 2435 2436 2437 2438
{
	return 0;
}
#endif /* !CONFIG_MODULE_SIG */

2439 2440
/* Sanity checks against invalid binaries, wrong arch, weird elf version. */
static int elf_header_check(struct load_info *info)
2441
{
2442 2443 2444 2445 2446 2447 2448 2449 2450 2451 2452 2453 2454
	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;
2455

2456 2457 2458 2459 2460 2461
	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)
2462 2463 2464
{
	int err;

2465 2466
	info->len = len;
	if (info->len < sizeof(*(info->hdr)))
2467 2468
		return -ENOEXEC;

2469 2470 2471 2472
	err = security_kernel_module_from_file(NULL);
	if (err)
		return err;

2473
	/* Suck in entire file: we'll want most of it. */
2474 2475
	info->hdr = vmalloc(info->len);
	if (!info->hdr)
2476 2477
		return -ENOMEM;

2478 2479 2480
	if (copy_from_user(info->hdr, umod, info->len) != 0) {
		vfree(info->hdr);
		return -EFAULT;
2481 2482
	}

2483 2484 2485 2486 2487 2488
	return 0;
}

/* Sets info->hdr and info->len. */
static int copy_module_from_fd(int fd, struct load_info *info)
{
2489
	struct fd f = fdget(fd);
2490 2491 2492 2493 2494
	int err;
	struct kstat stat;
	loff_t pos;
	ssize_t bytes = 0;

2495
	if (!f.file)
2496 2497
		return -ENOEXEC;

2498
	err = security_kernel_module_from_file(f.file);
2499
	if (err)
2500
		goto out;
2501

2502
	err = vfs_getattr(&f.file->f_path, &stat);
2503
	if (err)
2504
		goto out;
2505

2506 2507 2508
	if (stat.size > INT_MAX) {
		err = -EFBIG;
		goto out;
2509
	}
2510 2511 2512 2513 2514 2515 2516

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

2517 2518 2519 2520
	info->hdr = vmalloc(stat.size);
	if (!info->hdr) {
		err = -ENOMEM;
		goto out;
2521
	}
2522

2523 2524
	pos = 0;
	while (pos < stat.size) {
2525
		bytes = kernel_read(f.file, pos, (char *)(info->hdr) + pos,
2526 2527 2528 2529 2530 2531 2532 2533 2534 2535 2536
				    stat.size - pos);
		if (bytes < 0) {
			vfree(info->hdr);
			err = bytes;
			goto out;
		}
		if (bytes == 0)
			break;
		pos += bytes;
	}
	info->len = pos;
2537

2538
out:
2539
	fdput(f);
2540 2541 2542
	return err;
}

2543 2544 2545 2546 2547
static void free_copy(struct load_info *info)
{
	vfree(info->hdr);
}

2548
static int rewrite_section_headers(struct load_info *info, int flags)
2549 2550 2551 2552 2553 2554 2555 2556 2557 2558
{
	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) {
2559
			pr_err("Module len %lu truncated\n", info->len);
2560 2561 2562 2563 2564 2565 2566 2567 2568 2569 2570 2571 2572
			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
	}
2573 2574

	/* Track but don't keep modinfo and version sections. */
2575 2576 2577 2578
	if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
		info->index.vers = 0; /* Pretend no __versions section! */
	else
		info->index.vers = find_sec(info, "__versions");
2579
	info->index.info = find_sec(info, ".modinfo");
2580 2581
	info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
	info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
2582 2583 2584
	return 0;
}

L
Linus Torvalds 已提交
2585 2586 2587 2588 2589 2590 2591 2592
/*
 * 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).
 */
2593
static struct module *setup_load_info(struct load_info *info, int flags)
L
Linus Torvalds 已提交
2594 2595
{
	unsigned int i;
2596
	int err;
L
Linus Torvalds 已提交
2597 2598 2599 2600
	struct module *mod;

	/* Set up the convenience variables */
	info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
2601 2602
	info->secstrings = (void *)info->hdr
		+ info->sechdrs[info->hdr->e_shstrndx].sh_offset;
L
Linus Torvalds 已提交
2603

2604
	err = rewrite_section_headers(info, flags);
2605 2606
	if (err)
		return ERR_PTR(err);
L
Linus Torvalds 已提交
2607

2608 2609
	/* Find internal symbols and strings. */
	for (i = 1; i < info->hdr->e_shnum; i++) {
L
Linus Torvalds 已提交
2610 2611 2612
		if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
			info->index.sym = i;
			info->index.str = info->sechdrs[i].sh_link;
2613 2614 2615
			info->strtab = (char *)info->hdr
				+ info->sechdrs[info->index.str].sh_offset;
			break;
L
Linus Torvalds 已提交
2616 2617 2618
		}
	}

2619
	info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
L
Linus Torvalds 已提交
2620
	if (!info->index.mod) {
2621
		pr_warn("No module found in object\n");
L
Linus Torvalds 已提交
2622 2623 2624 2625 2626 2627
		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) {
2628
		pr_warn("%s: module has no symbols (stripped?)\n", mod->name);
L
Linus Torvalds 已提交
2629 2630 2631
		return ERR_PTR(-ENOEXEC);
	}

2632
	info->index.pcpu = find_pcpusec(info);
L
Linus Torvalds 已提交
2633 2634 2635 2636 2637 2638 2639 2640

	/* 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;
}

2641
static int check_modinfo(struct module *mod, struct load_info *info, int flags)
2642
{
2643
	const char *modmagic = get_modinfo(info, "vermagic");
2644 2645
	int err;

2646 2647 2648
	if (flags & MODULE_INIT_IGNORE_VERMAGIC)
		modmagic = NULL;

2649 2650 2651 2652 2653
	/* This is allowed: modprobe --force will invalidate it. */
	if (!modmagic) {
		err = try_to_force_load(mod, "bad vermagic");
		if (err)
			return err;
2654
	} else if (!same_magic(modmagic, vermagic, info->index.vers)) {
2655
		pr_err("%s: version magic '%s' should be '%s'\n",
2656 2657 2658 2659
		       mod->name, modmagic, vermagic);
		return -ENOEXEC;
	}

2660
	if (!get_modinfo(info, "intree"))
2661
		add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
2662

2663
	if (get_modinfo(info, "staging")) {
2664
		add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
2665 2666
		pr_warn("%s: module is from the staging directory, the quality "
			"is unknown, you have been warned.\n", mod->name);
2667
	}
2668 2669

	/* Set up license info based on the info section */
2670
	set_license(mod, get_modinfo(info, "license"));
2671

2672 2673 2674
	return 0;
}

2675
static int find_module_sections(struct module *mod, struct load_info *info)
2676
{
2677
	mod->kp = section_objs(info, "__param",
2678
			       sizeof(*mod->kp), &mod->num_kp);
2679
	mod->syms = section_objs(info, "__ksymtab",
2680
				 sizeof(*mod->syms), &mod->num_syms);
2681 2682
	mod->crcs = section_addr(info, "__kcrctab");
	mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
2683 2684
				     sizeof(*mod->gpl_syms),
				     &mod->num_gpl_syms);
2685 2686
	mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
	mod->gpl_future_syms = section_objs(info,
2687 2688 2689
					    "__ksymtab_gpl_future",
					    sizeof(*mod->gpl_future_syms),
					    &mod->num_gpl_future_syms);
2690
	mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future");
2691 2692

#ifdef CONFIG_UNUSED_SYMBOLS
2693
	mod->unused_syms = section_objs(info, "__ksymtab_unused",
2694 2695
					sizeof(*mod->unused_syms),
					&mod->num_unused_syms);
2696 2697
	mod->unused_crcs = section_addr(info, "__kcrctab_unused");
	mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl",
2698 2699
					    sizeof(*mod->unused_gpl_syms),
					    &mod->num_unused_gpl_syms);
2700
	mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl");
2701 2702
#endif
#ifdef CONFIG_CONSTRUCTORS
2703
	mod->ctors = section_objs(info, ".ctors",
2704
				  sizeof(*mod->ctors), &mod->num_ctors);
2705 2706 2707 2708 2709 2710 2711 2712 2713 2714 2715 2716
	if (!mod->ctors)
		mod->ctors = section_objs(info, ".init_array",
				sizeof(*mod->ctors), &mod->num_ctors);
	else if (find_sec(info, ".init_array")) {
		/*
		 * This shouldn't happen with same compiler and binutils
		 * building all parts of the module.
		 */
		printk(KERN_WARNING "%s: has both .ctors and .init_array.\n",
		       mod->name);
		return -EINVAL;
	}
2717 2718 2719
#endif

#ifdef CONFIG_TRACEPOINTS
2720 2721 2722
	mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
					     sizeof(*mod->tracepoints_ptrs),
					     &mod->num_tracepoints);
2723
#endif
2724 2725 2726 2727 2728
#ifdef HAVE_JUMP_LABEL
	mod->jump_entries = section_objs(info, "__jump_table",
					sizeof(*mod->jump_entries),
					&mod->num_jump_entries);
#endif
2729
#ifdef CONFIG_EVENT_TRACING
2730
	mod->trace_events = section_objs(info, "_ftrace_events",
2731 2732 2733
					 sizeof(*mod->trace_events),
					 &mod->num_trace_events);
#endif
2734 2735 2736 2737 2738
#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);
#endif
2739 2740
#ifdef CONFIG_FTRACE_MCOUNT_RECORD
	/* sechdrs[0].sh_size is always zero */
2741
	mod->ftrace_callsites = section_objs(info, "__mcount_loc",
2742 2743 2744
					     sizeof(*mod->ftrace_callsites),
					     &mod->num_ftrace_callsites);
#endif
2745

2746 2747 2748
	mod->extable = section_objs(info, "__ex_table",
				    sizeof(*mod->extable), &mod->num_exentries);

2749
	if (section_addr(info, "__obsparm"))
2750
		pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
2751 2752 2753

	info->debug = section_objs(info, "__verbose",
				   sizeof(*info->debug), &info->num_debug);
2754 2755

	return 0;
2756 2757
}

2758
static int move_module(struct module *mod, struct load_info *info)
2759 2760 2761 2762 2763 2764 2765 2766 2767 2768 2769 2770 2771
{
	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)
2772
		return -ENOMEM;
2773 2774 2775 2776

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

2777 2778 2779 2780 2781 2782 2783 2784 2785 2786 2787 2788 2789 2790 2791 2792 2793
	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;
2794 2795

	/* Transfer each section which specifies SHF_ALLOC */
2796
	pr_debug("final section addresses:\n");
2797
	for (i = 0; i < info->hdr->e_shnum; i++) {
2798
		void *dest;
2799
		Elf_Shdr *shdr = &info->sechdrs[i];
2800

2801
		if (!(shdr->sh_flags & SHF_ALLOC))
2802 2803
			continue;

2804
		if (shdr->sh_entsize & INIT_OFFSET_MASK)
2805
			dest = mod->module_init
2806
				+ (shdr->sh_entsize & ~INIT_OFFSET_MASK);
2807
		else
2808
			dest = mod->module_core + shdr->sh_entsize;
2809

2810 2811
		if (shdr->sh_type != SHT_NOBITS)
			memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
2812
		/* Update sh_addr to point to copy in image. */
2813
		shdr->sh_addr = (unsigned long)dest;
2814 2815
		pr_debug("\t0x%lx %s\n",
			 (long)shdr->sh_addr, info->secstrings + shdr->sh_name);
2816
	}
2817 2818

	return 0;
2819 2820
}

2821
static int check_module_license_and_versions(struct module *mod)
2822 2823 2824 2825 2826 2827 2828
{
	/*
	 * 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)
2829
		add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
2830 2831 2832

	/* driverloader was caught wrongly pretending to be under GPL */
	if (strcmp(mod->name, "driverloader") == 0)
2833 2834
		add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
				 LOCKDEP_NOW_UNRELIABLE);
2835

2836 2837
	/* lve claims to be GPL but upstream won't provide source */
	if (strcmp(mod->name, "lve") == 0)
2838 2839
		add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
				 LOCKDEP_NOW_UNRELIABLE);
2840

2841 2842 2843 2844 2845 2846 2847 2848 2849 2850 2851 2852 2853 2854 2855 2856 2857 2858 2859 2860 2861 2862 2863 2864 2865 2866 2867 2868 2869 2870 2871 2872 2873 2874 2875 2876 2877 2878 2879
#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);
}

2880 2881 2882 2883 2884 2885 2886 2887
int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
				     Elf_Shdr *sechdrs,
				     char *secstrings,
				     struct module *mod)
{
	return 0;
}

2888
static struct module *layout_and_allocate(struct load_info *info, int flags)
L
Linus Torvalds 已提交
2889
{
2890
	/* Module within temporary copy. */
L
Linus Torvalds 已提交
2891
	struct module *mod;
2892
	int err;
2893

2894
	mod = setup_load_info(info, flags);
2895 2896
	if (IS_ERR(mod))
		return mod;
L
Linus Torvalds 已提交
2897

2898
	err = check_modinfo(mod, info, flags);
2899 2900
	if (err)
		return ERR_PTR(err);
L
Linus Torvalds 已提交
2901 2902

	/* Allow arches to frob section contents and sizes.  */
2903 2904
	err = module_frob_arch_sections(info->hdr, info->sechdrs,
					info->secstrings, mod);
L
Linus Torvalds 已提交
2905
	if (err < 0)
2906
		return ERR_PTR(err);
L
Linus Torvalds 已提交
2907

2908 2909
	/* We will do a special allocation for per-cpu sections later. */
	info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC;
L
Linus Torvalds 已提交
2910 2911 2912 2913

	/* 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. */
2914 2915
	layout_sections(mod, info);
	layout_symtab(mod, info);
L
Linus Torvalds 已提交
2916

2917
	/* Allocate and move to the final place */
2918
	err = move_module(mod, info);
2919
	if (err)
2920
		return ERR_PTR(err);
2921 2922 2923

	/* Module has been copied to its final place now: return it. */
	mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2924
	kmemleak_load_module(mod, info);
2925 2926 2927 2928 2929 2930 2931 2932 2933 2934 2935
	return mod;
}

/* 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);
}

2936 2937 2938 2939 2940 2941 2942
int __weak module_finalize(const Elf_Ehdr *hdr,
			   const Elf_Shdr *sechdrs,
			   struct module *me)
{
	return 0;
}

2943 2944
static int post_relocation(struct module *mod, const struct load_info *info)
{
2945
	/* Sort exception table now relocations are done. */
2946 2947 2948 2949 2950 2951
	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);

2952
	/* Setup kallsyms-specific fields. */
2953 2954 2955 2956 2957 2958
	add_kallsyms(mod, info);

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

2959 2960 2961 2962 2963 2964 2965
/* 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);
2966
	mod = find_module_all(name, strlen(name), true);
2967 2968
	ret = !mod || mod->state == MODULE_STATE_LIVE
		|| mod->state == MODULE_STATE_GOING;
2969 2970 2971 2972 2973
	mutex_unlock(&module_mutex);

	return ret;
}

2974 2975 2976 2977 2978 2979 2980 2981 2982 2983 2984 2985 2986 2987 2988 2989
/* 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;

2990 2991 2992 2993 2994 2995
	/*
	 * 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;

2996 2997 2998 2999 3000 3001 3002 3003 3004 3005 3006 3007 3008 3009 3010 3011 3012
	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) {
3013 3014 3015 3016
		pr_warn("%s: '%s'->init suspiciously returned %d, it should "
			"follow 0/-E convention\n"
			"%s: loading module anyway...\n",
			__func__, mod->name, ret, __func__);
3017 3018 3019 3020 3021 3022 3023 3024
		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);

3025 3026 3027 3028 3029 3030 3031 3032 3033 3034 3035 3036 3037 3038 3039 3040 3041 3042 3043
	/*
	 * 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();
3044 3045 3046 3047 3048 3049 3050 3051 3052 3053 3054 3055 3056 3057 3058 3059 3060 3061 3062 3063 3064 3065 3066 3067 3068 3069 3070 3071 3072 3073

	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;
}

3074 3075 3076 3077 3078 3079 3080 3081 3082 3083 3084 3085 3086 3087
/*
 * 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);
3088 3089
	old = find_module_all(mod->name, strlen(mod->name), true);
	if (old != NULL) {
3090 3091 3092 3093 3094 3095 3096 3097 3098 3099 3100 3101 3102 3103 3104 3105 3106 3107 3108 3109 3110 3111 3112 3113 3114 3115 3116 3117 3118 3119 3120 3121 3122 3123 3124 3125
		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);

3126 3127 3128 3129 3130 3131 3132 3133 3134 3135 3136 3137
	/* 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);

3138 3139 3140
	/* Mark state as coming so strong_try_module_get() ignores us,
	 * but kallsyms etc. can see us. */
	mod->state = MODULE_STATE_COMING;
3141 3142 3143 3144 3145
	mutex_unlock(&module_mutex);

	blocking_notifier_call_chain(&module_notify_list,
				     MODULE_STATE_COMING, mod);
	return 0;
3146 3147 3148 3149 3150 3151

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

3152 3153 3154 3155
static int unknown_module_param_cb(char *param, char *val, const char *modname)
{
	/* Check for magic 'dyndbg' arg */ 
	int ret = ddebug_dyndbg_module_param_cb(param, val, modname);
3156 3157
	if (ret != 0)
		pr_warn("%s: unknown parameter '%s' ignored\n", modname, param);
3158 3159 3160
	return 0;
}

3161 3162
/* Allocate and load the module: note that size of section 0 is always
   zero, and we rely on this for optional sections. */
3163 3164
static int load_module(struct load_info *info, const char __user *uargs,
		       int flags)
3165
{
3166
	struct module *mod;
3167
	long err;
3168
	char *after_dashes;
3169

3170 3171 3172
	err = module_sig_check(info);
	if (err)
		goto free_copy;
3173

3174
	err = elf_header_check(info);
3175
	if (err)
3176
		goto free_copy;
3177 3178

	/* Figure out module layout, and allocate all the memory. */
3179
	mod = layout_and_allocate(info, flags);
3180 3181
	if (IS_ERR(mod)) {
		err = PTR_ERR(mod);
3182
		goto free_copy;
L
Linus Torvalds 已提交
3183 3184
	}

3185 3186 3187
	/* Reserve our place in the list. */
	err = add_unformed_module(mod);
	if (err)
3188 3189
		goto free_module;

3190
#ifdef CONFIG_MODULE_SIG
3191
	mod->sig_ok = info->sig_ok;
3192
	if (!mod->sig_ok) {
3193 3194 3195
		pr_notice_once("%s: module verification failed: signature "
			       "and/or  required key missing - tainting "
			       "kernel\n", mod->name);
3196
		add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK);
3197
	}
3198 3199
#endif

3200
	/* To avoid stressing percpu allocator, do this once we're unique. */
3201
	err = percpu_modalloc(mod, info);
3202 3203 3204
	if (err)
		goto unlink_mod;

3205
	/* Now module is in final location, initialize linked lists, etc. */
3206 3207
	err = module_unload_init(mod);
	if (err)
3208
		goto unlink_mod;
L
Linus Torvalds 已提交
3209

3210 3211
	/* Now we've got everything in the final locations, we can
	 * find optional sections. */
3212 3213 3214
	err = find_module_sections(mod, info);
	if (err)
		goto free_unload;
3215

3216
	err = check_module_license_and_versions(mod);
3217 3218
	if (err)
		goto free_unload;
3219

3220
	/* Set up MODINFO_ATTR fields */
3221
	setup_modinfo(mod, info);
3222

L
Linus Torvalds 已提交
3223
	/* Fix up syms, so that st_value is a pointer to location. */
3224
	err = simplify_symbols(mod, info);
L
Linus Torvalds 已提交
3225
	if (err < 0)
3226
		goto free_modinfo;
L
Linus Torvalds 已提交
3227

3228
	err = apply_relocations(mod, info);
3229
	if (err < 0)
3230
		goto free_modinfo;
L
Linus Torvalds 已提交
3231

3232
	err = post_relocation(mod, info);
L
Linus Torvalds 已提交
3233
	if (err < 0)
3234
		goto free_modinfo;
L
Linus Torvalds 已提交
3235

3236
	flush_module_icache(mod);
3237

3238 3239 3240 3241 3242 3243
	/* 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;
	}
3244

3245
	dynamic_debug_setup(info->debug, info->num_debug);
3246

3247 3248 3249
	/* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
	ftrace_module_init(mod);

3250 3251 3252
	/* Finally it's fully formed, ready to start executing. */
	err = complete_formation(mod, info);
	if (err)
3253
		goto ddebug_cleanup;
3254

3255
	/* Module is ready to execute: parsing args may do that. */
3256 3257 3258 3259
	after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
				  -32768, 32767, unknown_module_param_cb);
	if (IS_ERR(after_dashes)) {
		err = PTR_ERR(after_dashes);
3260
		goto bug_cleanup;
3261 3262 3263 3264
	} else if (after_dashes) {
		pr_warn("%s: parameters '%s' after `--' ignored\n",
		       mod->name, after_dashes);
	}
L
Linus Torvalds 已提交
3265

3266
	/* Link in to syfs. */
3267
	err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
L
Linus Torvalds 已提交
3268
	if (err < 0)
3269
		goto bug_cleanup;
3270

3271
	/* Get rid of temporary copy. */
3272
	free_copy(info);
L
Linus Torvalds 已提交
3273 3274

	/* Done! */
3275
	trace_module_load(mod);
3276 3277

	return do_init_module(mod);
L
Linus Torvalds 已提交
3278

3279 3280
 bug_cleanup:
	/* module_bug_cleanup needs module_mutex protection */
3281
	mutex_lock(&module_mutex);
3282
	module_bug_cleanup(mod);
3283
	mutex_unlock(&module_mutex);
3284 3285 3286 3287 3288

	/* we can't deallocate the module until we clear memory protection */
	unset_module_init_ro_nx(mod);
	unset_module_core_ro_nx(mod);

3289
 ddebug_cleanup:
3290
	dynamic_debug_remove(info->debug);
3291
	synchronize_sched();
3292 3293
	kfree(mod->args);
 free_arch_cleanup:
L
Linus Torvalds 已提交
3294
	module_arch_cleanup(mod);
3295
 free_modinfo:
3296
	free_modinfo(mod);
3297
 free_unload:
L
Linus Torvalds 已提交
3298
	module_unload_free(mod);
3299 3300 3301 3302 3303
 unlink_mod:
	mutex_lock(&module_mutex);
	/* Unlink carefully: kallsyms could be walking list. */
	list_del_rcu(&mod->list);
	wake_up_all(&module_wq);
3304 3305
	/* Wait for RCU synchronizing before releasing mod->list. */
	synchronize_rcu();
3306
	mutex_unlock(&module_mutex);
3307
 free_module:
3308
	module_deallocate(mod, info);
3309
 free_copy:
3310 3311
	free_copy(info);
	return err;
3312 3313
}

3314 3315
SYSCALL_DEFINE3(init_module, void __user *, umod,
		unsigned long, len, const char __user *, uargs)
L
Linus Torvalds 已提交
3316
{
3317 3318
	int err;
	struct load_info info = { };
L
Linus Torvalds 已提交
3319

3320 3321 3322
	err = may_init_module();
	if (err)
		return err;
L
Linus Torvalds 已提交
3323

3324 3325
	pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
	       umod, len, uargs);
L
Linus Torvalds 已提交
3326

3327 3328 3329
	err = copy_module_from_user(umod, len, &info);
	if (err)
		return err;
L
Linus Torvalds 已提交
3330

3331
	return load_module(&info, uargs, 0);
3332
}
3333

3334
SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
3335 3336 3337
{
	int err;
	struct load_info info = { };
3338

3339 3340 3341
	err = may_init_module();
	if (err)
		return err;
L
Linus Torvalds 已提交
3342

3343
	pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags);
3344

3345 3346 3347
	if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS
		      |MODULE_INIT_IGNORE_VERMAGIC))
		return -EINVAL;
3348

3349 3350 3351
	err = copy_module_from_fd(fd, &info);
	if (err)
		return err;
L
Linus Torvalds 已提交
3352

3353
	return load_module(&info, uargs, flags);
L
Linus Torvalds 已提交
3354 3355 3356 3357 3358 3359 3360 3361 3362 3363 3364 3365 3366 3367
}

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 $d.
 */
static inline int is_arm_mapping_symbol(const char *str)
{
3368 3369
	if (str[0] == '.' && str[1] == 'L')
		return true;
3370
	return str[0] == '$' && strchr("axtd", str[1])
L
Linus Torvalds 已提交
3371 3372 3373 3374 3375 3376 3377 3378 3379 3380 3381 3382
	       && (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 */
3383
	if (within_module_init(addr, mod))
L
Linus Torvalds 已提交
3384
		nextval = (unsigned long)mod->module_init+mod->init_text_size;
3385
	else
L
Linus Torvalds 已提交
3386 3387
		nextval = (unsigned long)mod->module_core+mod->core_text_size;

L
Lucas De Marchi 已提交
3388
	/* Scan for closest preceding symbol, and next symbol. (ELF
3389
	   starts real symbols at 1). */
L
Linus Torvalds 已提交
3390 3391 3392 3393 3394 3395 3396 3397 3398 3399 3400 3401 3402 3403 3404 3405 3406 3407 3408 3409 3410
	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;

3411 3412 3413 3414
	if (size)
		*size = nextval - mod->symtab[best].st_value;
	if (offset)
		*offset = addr - mod->symtab[best].st_value;
L
Linus Torvalds 已提交
3415 3416 3417
	return mod->strtab + mod->symtab[best].st_name;
}

3418 3419
/* For kallsyms to ask for address resolution.  NULL means not found.  Careful
 * not to lock to avoid deadlock on oopses, simply disable preemption. */
3420
const char *module_address_lookup(unsigned long addr,
3421 3422 3423 3424
			    unsigned long *size,
			    unsigned long *offset,
			    char **modname,
			    char *namebuf)
L
Linus Torvalds 已提交
3425 3426
{
	struct module *mod;
3427
	const char *ret = NULL;
L
Linus Torvalds 已提交
3428

3429
	preempt_disable();
3430
	list_for_each_entry_rcu(mod, &modules, list) {
3431 3432
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
3433
		if (within_module(addr, mod)) {
3434 3435
			if (modname)
				*modname = mod->name;
3436 3437
			ret = get_ksymbol(mod, addr, size, offset);
			break;
L
Linus Torvalds 已提交
3438 3439
		}
	}
3440 3441 3442 3443 3444
	/* Make a copy in here where it's safe */
	if (ret) {
		strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
		ret = namebuf;
	}
3445
	preempt_enable();
3446
	return ret;
L
Linus Torvalds 已提交
3447 3448
}

3449 3450 3451 3452
int lookup_module_symbol_name(unsigned long addr, char *symname)
{
	struct module *mod;

3453
	preempt_disable();
3454
	list_for_each_entry_rcu(mod, &modules, list) {
3455 3456
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
3457
		if (within_module(addr, mod)) {
3458 3459 3460 3461 3462
			const char *sym;

			sym = get_ksymbol(mod, addr, NULL, NULL);
			if (!sym)
				goto out;
3463
			strlcpy(symname, sym, KSYM_NAME_LEN);
3464
			preempt_enable();
3465 3466 3467 3468
			return 0;
		}
	}
out:
3469
	preempt_enable();
3470 3471 3472
	return -ERANGE;
}

3473 3474 3475 3476 3477
int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
			unsigned long *offset, char *modname, char *name)
{
	struct module *mod;

3478
	preempt_disable();
3479
	list_for_each_entry_rcu(mod, &modules, list) {
3480 3481
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
3482
		if (within_module(addr, mod)) {
3483 3484 3485 3486 3487 3488
			const char *sym;

			sym = get_ksymbol(mod, addr, size, offset);
			if (!sym)
				goto out;
			if (modname)
3489
				strlcpy(modname, mod->name, MODULE_NAME_LEN);
3490
			if (name)
3491
				strlcpy(name, sym, KSYM_NAME_LEN);
3492
			preempt_enable();
3493 3494 3495 3496
			return 0;
		}
	}
out:
3497
	preempt_enable();
3498 3499 3500
	return -ERANGE;
}

3501 3502
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
3503 3504 3505
{
	struct module *mod;

3506
	preempt_disable();
3507
	list_for_each_entry_rcu(mod, &modules, list) {
3508 3509
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
L
Linus Torvalds 已提交
3510 3511 3512
		if (symnum < mod->num_symtab) {
			*value = mod->symtab[symnum].st_value;
			*type = mod->symtab[symnum].st_info;
3513
			strlcpy(name, mod->strtab + mod->symtab[symnum].st_name,
3514 3515
				KSYM_NAME_LEN);
			strlcpy(module_name, mod->name, MODULE_NAME_LEN);
3516
			*exported = is_exported(name, *value, mod);
3517
			preempt_enable();
3518
			return 0;
L
Linus Torvalds 已提交
3519 3520 3521
		}
		symnum -= mod->num_symtab;
	}
3522
	preempt_enable();
3523
	return -ERANGE;
L
Linus Torvalds 已提交
3524 3525 3526 3527 3528 3529 3530
}

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

	for (i = 0; i < mod->num_symtab; i++)
3531 3532
		if (strcmp(name, mod->strtab+mod->symtab[i].st_name) == 0 &&
		    mod->symtab[i].st_info != 'U')
L
Linus Torvalds 已提交
3533 3534 3535 3536 3537 3538 3539 3540 3541 3542 3543 3544
			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. */
3545
	preempt_disable();
L
Linus Torvalds 已提交
3546
	if ((colon = strchr(name, ':')) != NULL) {
3547
		if ((mod = find_module_all(name, colon - name, false)) != NULL)
L
Linus Torvalds 已提交
3548 3549
			ret = mod_find_symname(mod, colon+1);
	} else {
3550 3551 3552
		list_for_each_entry_rcu(mod, &modules, list) {
			if (mod->state == MODULE_STATE_UNFORMED)
				continue;
L
Linus Torvalds 已提交
3553 3554
			if ((ret = mod_find_symname(mod, name)) != 0)
				break;
3555
		}
L
Linus Torvalds 已提交
3556
	}
3557
	preempt_enable();
L
Linus Torvalds 已提交
3558 3559
	return ret;
}
3560 3561 3562 3563 3564 3565 3566 3567 3568 3569

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) {
3570 3571
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
3572 3573 3574 3575 3576 3577 3578 3579 3580
		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
3581 3582
#endif /* CONFIG_KALLSYMS */

3583
static char *module_flags(struct module *mod, char *buf)
3584 3585 3586
{
	int bx = 0;

3587
	BUG_ON(mod->state == MODULE_STATE_UNFORMED);
3588 3589 3590
	if (mod->taints ||
	    mod->state == MODULE_STATE_GOING ||
	    mod->state == MODULE_STATE_COMING) {
3591
		buf[bx++] = '(';
3592
		bx += module_flags_taint(mod, buf + bx);
3593 3594 3595 3596 3597 3598
		/* 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++] = '+';
3599 3600 3601 3602 3603 3604 3605
		buf[bx++] = ')';
	}
	buf[bx] = '\0';

	return buf;
}

3606 3607 3608 3609 3610 3611 3612 3613 3614 3615 3616 3617 3618 3619 3620 3621 3622 3623
#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
3624 3625 3626
static int m_show(struct seq_file *m, void *p)
{
	struct module *mod = list_entry(p, struct module, list);
3627 3628
	char buf[8];

3629 3630 3631 3632
	/* We always ignore unformed modules. */
	if (mod->state == MODULE_STATE_UNFORMED)
		return 0;

3633
	seq_printf(m, "%s %u",
L
Linus Torvalds 已提交
3634 3635 3636 3637 3638 3639 3640 3641 3642
		   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. */
3643
	seq_printf(m, " 0x%pK", mod->module_core);
L
Linus Torvalds 已提交
3644

3645 3646
	/* Taints info */
	if (mod->taints)
3647
		seq_printf(m, " %s", module_flags(mod, buf));
3648

L
Linus Torvalds 已提交
3649 3650 3651 3652 3653 3654 3655 3656 3657
	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 -.
*/
3658
static const struct seq_operations modules_op = {
L
Linus Torvalds 已提交
3659 3660 3661 3662 3663 3664
	.start	= m_start,
	.next	= m_next,
	.stop	= m_stop,
	.show	= m_show
};

3665 3666 3667 3668 3669 3670 3671 3672 3673 3674 3675 3676 3677 3678 3679 3680 3681 3682 3683 3684
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
3685 3686 3687 3688 3689 3690
/* 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;

3691
	preempt_disable();
3692
	list_for_each_entry_rcu(mod, &modules, list) {
3693 3694
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
L
Linus Torvalds 已提交
3695 3696
		if (mod->num_exentries == 0)
			continue;
3697

L
Linus Torvalds 已提交
3698 3699 3700 3701 3702 3703
		e = search_extable(mod->extable,
				   mod->extable + mod->num_exentries - 1,
				   addr);
		if (e)
			break;
	}
3704
	preempt_enable();
L
Linus Torvalds 已提交
3705 3706

	/* Now, if we found one, we are running inside it now, hence
3707
	   we cannot unload the module, hence no refcnt needed. */
L
Linus Torvalds 已提交
3708 3709 3710
	return e;
}

3711
/*
R
Rusty Russell 已提交
3712 3713 3714 3715 3716
 * 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).
3717
 */
R
Rusty Russell 已提交
3718
bool is_module_address(unsigned long addr)
3719
{
R
Rusty Russell 已提交
3720
	bool ret;
3721

3722
	preempt_disable();
R
Rusty Russell 已提交
3723
	ret = __module_address(addr) != NULL;
3724
	preempt_enable();
3725

R
Rusty Russell 已提交
3726
	return ret;
3727 3728
}

R
Rusty Russell 已提交
3729 3730 3731 3732 3733 3734 3735
/*
 * __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.
 */
3736
struct module *__module_address(unsigned long addr)
L
Linus Torvalds 已提交
3737 3738 3739
{
	struct module *mod;

3740 3741 3742
	if (addr < module_addr_min || addr > module_addr_max)
		return NULL;

3743 3744 3745
	list_for_each_entry_rcu(mod, &modules, list) {
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
3746
		if (within_module(addr, mod))
L
Linus Torvalds 已提交
3747
			return mod;
3748
	}
L
Linus Torvalds 已提交
3749 3750
	return NULL;
}
3751
EXPORT_SYMBOL_GPL(__module_address);
L
Linus Torvalds 已提交
3752

R
Rusty Russell 已提交
3753 3754 3755 3756 3757 3758 3759 3760 3761 3762 3763 3764 3765 3766 3767 3768 3769 3770 3771 3772 3773 3774 3775 3776 3777 3778 3779 3780 3781 3782 3783 3784 3785 3786 3787 3788 3789
/*
 * 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;
}
3790
EXPORT_SYMBOL_GPL(__module_text_address);
R
Rusty Russell 已提交
3791

L
Linus Torvalds 已提交
3792 3793 3794 3795
/* Don't grab lock, we're oopsing. */
void print_modules(void)
{
	struct module *mod;
3796
	char buf[8];
L
Linus Torvalds 已提交
3797

3798
	printk(KERN_DEFAULT "Modules linked in:");
3799 3800
	/* Most callers should already have preempt disabled, but make sure */
	preempt_disable();
3801 3802 3803
	list_for_each_entry_rcu(mod, &modules, list) {
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
J
Jiri Slaby 已提交
3804
		pr_cont(" %s%s", mod->name, module_flags(mod, buf));
3805
	}
3806
	preempt_enable();
3807
	if (last_unloaded_module[0])
J
Jiri Slaby 已提交
3808 3809
		pr_cont(" [last unloaded: %s]", last_unloaded_module);
	pr_cont("\n");
L
Linus Torvalds 已提交
3810 3811 3812
}

#ifdef CONFIG_MODVERSIONS
3813 3814 3815 3816 3817 3818
/* 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,
3819
		   struct tracepoint * const *tp)
3820 3821 3822
{
}
EXPORT_SYMBOL(module_layout);
L
Linus Torvalds 已提交
3823
#endif
反馈
建议
客服 返回
顶部