module.c 98.0 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>
R
Roland McGrath 已提交
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>
A
Al Viro 已提交
44
#include <linux/sched.h>
L
Linus Torvalds 已提交
45
#include <linux/device.h>
46
#include <linux/string.h>
A
Arjan van de Ven 已提交
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>
M
Mathieu Desnoyers 已提交
54
#include <linux/tracepoint.h>
55
#include <linux/ftrace.h>
56
#include <linux/async.h>
57
#include <linux/percpu.h>
C
Catalin Marinas 已提交
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>
R
Rusty Russell 已提交
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 */

R
Rusty Russell 已提交
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,
R
Rusty Russell 已提交
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;

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

166
int unregister_module_notifier(struct notifier_block *nb)
L
Linus Torvalds 已提交
167
{
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;
R
Rusty Russell 已提交
177
	unsigned long symoffs, stroffs;
178 179
	struct _ddebug *debug;
	unsigned int num_debug;
R
Rusty Russell 已提交
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);
A
Andi Kleen 已提交
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);
D
Daniel Walker 已提交
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;
}

R
Rusty Russell 已提交
232
/* Find a module section, or NULL. */
233
static void *section_addr(const struct load_info *info, const char *name)
R
Rusty Russell 已提交
234 235
{
	/* Section 0 has sh_addr 0. */
236
	return (void *)info->sechdrs[find_sec(info, name)].sh_addr;
R
Rusty Russell 已提交
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,
R
Rusty Russell 已提交
241 242 243 244
			  const char *name,
			  size_t object_size,
			  unsigned int *num)
{
245
	unsigned int sec = find_sec(info, name);
R
Rusty Russell 已提交
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;
R
Rusty Russell 已提交
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
A
Andrew Morton 已提交
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) {
A
Andrew Morton 已提交
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) {
A
Andrew Morton 已提交
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

R
Rusty Russell 已提交
482
static int percpu_modalloc(struct module *mod, struct load_info *info)
483
{
R
Rusty Russell 已提交
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) {
A
Andrew Morton 已提交
491 492
		pr_warn("%s: per-cpu alignment %li > %li\n",
			mod->name, align, PAGE_SIZE);
493 494 495
		align = PAGE_SIZE;
	}

R
Rusty Russell 已提交
496
	mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align);
497
	if (!mod->percpu) {
A
Andrew Morton 已提交
498 499
		pr_warn("%s: Could not allocate %lu bytes percpu data\n",
			mod->name, (unsigned long)pcpusec->sh_size);
500 501
		return -ENOMEM;
	}
R
Rusty Russell 已提交
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;
}
R
Rusty Russell 已提交
567
static int percpu_modalloc(struct module *mod, struct load_info *info)
568
{
R
Rusty Russell 已提交
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)                  \
{                                                                     \
D
Daniel Walker 已提交
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
	/*
	 * Initialize reference counter to MODULE_REF_BASE.
	 * refcnt == 0 means module is going.
	 */
	atomic_set(&mod->refcnt, MODULE_REF_BASE);
641

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) {
A
Andrew Morton 已提交
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
	return ret;
}
L
Linus Torvalds 已提交
759

760 761
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
}

775 776 777 778 779 780 781 782 783 784
/**
 * module_refcount - return the refcount or -1 if unloading
 *
 * @mod:	the module we're checking
 *
 * Returns:
 *	-1 if the module is in the process of unloading
 *	otherwise the number of references in the kernel to the module
 */
int module_refcount(struct module *mod)
L
Linus Torvalds 已提交
785
{
786
	return atomic_read(&mod->refcnt) - MODULE_REF_BASE;
L
Linus Torvalds 已提交
787 788 789 790 791 792
}
EXPORT_SYMBOL(module_refcount);

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

793 794
SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
		unsigned int, flags)
L
Linus Torvalds 已提交
795 796
{
	struct module *mod;
797
	char name[MODULE_NAME_LEN];
L
Linus Torvalds 已提交
798 799
	int ret, forced = 0;

800
	if (!capable(CAP_SYS_MODULE) || modules_disabled)
801 802 803 804 805 806
		return -EPERM;

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

807 808
	if (mutex_lock_interruptible(&module_mutex) != 0)
		return -EINTR;
L
Linus Torvalds 已提交
809 810 811 812 813 814 815

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

816
	if (!list_empty(&mod->source_list)) {
L
Linus Torvalds 已提交
817 818 819 820 821 822 823
		/* 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) {
824
		/* FIXME: if (force), slam module count damn the torpedoes */
825
		pr_debug("%s already dying\n", mod->name);
L
Linus Torvalds 已提交
826 827 828 829 830
		ret = -EBUSY;
		goto out;
	}

	/* If it has an init func, it must have an exit func to unload */
R
Rusty Russell 已提交
831
	if (mod->init && !mod->exit) {
832
		forced = try_force_unload(flags);
L
Linus Torvalds 已提交
833 834 835 836 837 838 839 840 841 842 843 844
		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;

845
	mutex_unlock(&module_mutex);
L
Lucas De Marchi 已提交
846
	/* Final destruction now no one is using it. */
847
	if (mod->exit != NULL)
L
Linus Torvalds 已提交
848
		mod->exit();
849 850
	blocking_notifier_call_chain(&module_notify_list,
				     MODULE_STATE_GOING, mod);
851
	async_synchronize_full();
852

853
	/* Store the name of the last unloaded module for diagnostic purposes */
854
	strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
L
Linus Torvalds 已提交
855

856 857 858
	free_module(mod);
	return 0;
out:
859
	mutex_unlock(&module_mutex);
L
Linus Torvalds 已提交
860 861 862
	return ret;
}

863
static inline void print_unload_info(struct seq_file *m, struct module *mod)
L
Linus Torvalds 已提交
864 865 866 867
{
	struct module_use *use;
	int printed_something = 0;

868
	seq_printf(m, " %i ", module_refcount(mod));
L
Linus Torvalds 已提交
869

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

	if (mod->init != NULL && mod->exit == NULL) {
		printed_something = 1;
881
		seq_puts(m, "[permanent],");
L
Linus Torvalds 已提交
882 883 884
	}

	if (!printed_something)
885
		seq_puts(m, "-");
L
Linus Torvalds 已提交
886 887 888 889 890 891
}

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

R
Rusty Russell 已提交
892
	preempt_disable();
893
	if (!find_symbol(symbol, &owner, NULL, true, false))
L
Linus Torvalds 已提交
894 895
		BUG();
	module_put(owner);
R
Rusty Russell 已提交
896
	preempt_enable();
L
Linus Torvalds 已提交
897 898 899
}
EXPORT_SYMBOL(__symbol_put);

900
/* Note this assumes addr is a function, which it currently always is. */
L
Linus Torvalds 已提交
901 902
void symbol_put_addr(void *addr)
{
903
	struct module *modaddr;
904
	unsigned long a = (unsigned long)dereference_function_descriptor(addr);
L
Linus Torvalds 已提交
905

906
	if (core_kernel_text(a))
907
		return;
L
Linus Torvalds 已提交
908

909 910
	/* module_text_address is safe here: we're supposed to have reference
	 * to module from symbol_get, so it can't go away. */
911
	modaddr = __module_text_address(a);
912
	BUG_ON(!modaddr);
913
	module_put(modaddr);
L
Linus Torvalds 已提交
914 915 916 917
}
EXPORT_SYMBOL_GPL(symbol_put_addr);

static ssize_t show_refcnt(struct module_attribute *mattr,
918
			   struct module_kobject *mk, char *buffer)
L
Linus Torvalds 已提交
919
{
920
	return sprintf(buffer, "%i\n", module_refcount(mk->mod));
L
Linus Torvalds 已提交
921 922
}

923 924
static struct module_attribute modinfo_refcnt =
	__ATTR(refcnt, 0444, show_refcnt, NULL);
L
Linus Torvalds 已提交
925

926 927 928 929
void __module_get(struct module *module)
{
	if (module) {
		preempt_disable();
930
		atomic_inc(&module->refcnt);
931 932 933 934 935 936 937 938 939 940 941 942
		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();
943 944 945
		/* Note: here, we can fail to get a reference */
		if (likely(module_is_live(module) &&
			   atomic_inc_not_zero(&module->refcnt) != 0))
946
			trace_module_get(module, _RET_IP_);
947
		else
948 949 950 951 952 953 954 955
			ret = false;

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

A
Al Viro 已提交
956 957
void module_put(struct module *module)
{
958 959
	int ret;

A
Al Viro 已提交
960
	if (module) {
961
		preempt_disable();
962 963
		ret = atomic_dec_if_positive(&module->refcnt);
		WARN_ON(ret < 0);	/* Failed to put refcount */
964
		trace_module_put(module, _RET_IP_);
965
		preempt_enable();
A
Al Viro 已提交
966 967 968 969
	}
}
EXPORT_SYMBOL(module_put);

L
Linus Torvalds 已提交
970
#else /* !CONFIG_MODULE_UNLOAD */
971
static inline void print_unload_info(struct seq_file *m, struct module *mod)
L
Linus Torvalds 已提交
972 973
{
	/* We don't know the usage count, or what modules are using. */
974
	seq_puts(m, " - -");
L
Linus Torvalds 已提交
975 976 977 978 979 980
}

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

981
int ref_module(struct module *a, struct module *b)
L
Linus Torvalds 已提交
982
{
983
	return strong_try_module_get(b);
L
Linus Torvalds 已提交
984
}
985
EXPORT_SYMBOL_GPL(ref_module);
L
Linus Torvalds 已提交
986

987
static inline int module_unload_init(struct module *mod)
L
Linus Torvalds 已提交
988
{
989
	return 0;
L
Linus Torvalds 已提交
990 991 992
}
#endif /* CONFIG_MODULE_UNLOAD */

993 994 995 996 997 998 999 1000 1001 1002 1003 1004
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';
1005
	if (mod->taints & (1 << TAINT_UNSIGNED_MODULE))
1006
		buf[l++] = 'E';
1007 1008
	/*
	 * TAINT_FORCED_RMMOD: could be added.
1009
	 * TAINT_CPU_OUT_OF_SPEC, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't
1010 1011 1012 1013 1014
	 * apply to modules.
	 */
	return l;
}

1015
static ssize_t show_initstate(struct module_attribute *mattr,
1016
			      struct module_kobject *mk, char *buffer)
1017 1018 1019
{
	const char *state = "unknown";

1020
	switch (mk->mod->state) {
1021 1022 1023 1024 1025 1026 1027 1028 1029
	case MODULE_STATE_LIVE:
		state = "live";
		break;
	case MODULE_STATE_COMING:
		state = "coming";
		break;
	case MODULE_STATE_GOING:
		state = "going";
		break;
1030 1031
	default:
		BUG();
1032 1033 1034 1035
	}
	return sprintf(buffer, "%s\n", state);
}

1036 1037
static struct module_attribute modinfo_initstate =
	__ATTR(initstate, 0444, show_initstate, NULL);
1038

1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049
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;
}

1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082
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);
1083

1084
static struct module_attribute *modinfo_attrs[] = {
1085
	&module_uevent,
1086 1087
	&modinfo_version,
	&modinfo_srcversion,
1088 1089 1090 1091
	&modinfo_initstate,
	&modinfo_coresize,
	&modinfo_initsize,
	&modinfo_taint,
1092
#ifdef CONFIG_MODULE_UNLOAD
1093
	&modinfo_refcnt,
1094 1095 1096 1097
#endif
	NULL,
};

L
Linus Torvalds 已提交
1098 1099
static const char vermagic[] = VERMAGIC_STRING;

1100
static int try_to_force_load(struct module *mod, const char *reason)
1101 1102
{
#ifdef CONFIG_MODULE_FORCE_LOAD
A
Andi Kleen 已提交
1103
	if (!test_taint(TAINT_FORCED_MODULE))
A
Andrew Morton 已提交
1104
		pr_warn("%s: %s: kernel tainted.\n", mod->name, reason);
1105
	add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
1106 1107 1108 1109 1110 1111
	return 0;
#else
	return -ENOEXEC;
#endif
}

L
Linus Torvalds 已提交
1112
#ifdef CONFIG_MODVERSIONS
1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123
/* 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
1124 1125 1126
static int check_version(Elf_Shdr *sechdrs,
			 unsigned int versindex,
			 const char *symname,
1127
			 struct module *mod,
1128 1129
			 const unsigned long *crc,
			 const struct module *crc_owner)
L
Linus Torvalds 已提交
1130 1131 1132 1133 1134 1135 1136 1137
{
	unsigned int i, num_versions;
	struct modversion_info *versions;

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

1138 1139 1140 1141
	/* 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
1142 1143 1144 1145 1146 1147 1148 1149
	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;

1150
		if (versions[i].crc == maybe_relocated(*crc, crc_owner))
L
Linus Torvalds 已提交
1151
			return 1;
1152
		pr_debug("Found checksum %lX vs module %lX\n",
1153
		       maybe_relocated(*crc, crc_owner), versions[i].crc);
1154
		goto bad_version;
L
Linus Torvalds 已提交
1155
	}
1156

A
Andrew Morton 已提交
1157
	pr_warn("%s: no symbol version for %s\n", mod->name, symname);
1158
	return 0;
1159 1160

bad_version:
1161
	pr_warn("%s: disagrees about version of symbol %s\n",
1162 1163
	       mod->name, symname);
	return 0;
L
Linus Torvalds 已提交
1164 1165 1166 1167 1168 1169 1170 1171
}

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

1172 1173
	/* Since this should be found in kernel (which can't be removed),
	 * no locking is necessary. */
R
Rusty Russell 已提交
1174
	if (!find_symbol(VMLINUX_SYMBOL_STR(module_layout), NULL,
1175
			 &crc, true, false))
L
Linus Torvalds 已提交
1176
		BUG();
1177 1178
	return check_version(sechdrs, versindex,
			     VMLINUX_SYMBOL_STR(module_layout), mod, crc,
1179
			     NULL);
L
Linus Torvalds 已提交
1180 1181
}

1182 1183 1184
/* 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
1185
{
1186 1187 1188 1189
	if (has_crcs) {
		amagic += strcspn(amagic, " ");
		bmagic += strcspn(bmagic, " ");
	}
L
Linus Torvalds 已提交
1190 1191 1192 1193 1194 1195
	return strcmp(amagic, bmagic) == 0;
}
#else
static inline int check_version(Elf_Shdr *sechdrs,
				unsigned int versindex,
				const char *symname,
1196
				struct module *mod,
1197 1198
				const unsigned long *crc,
				const struct module *crc_owner)
L
Linus Torvalds 已提交
1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209
{
	return 1;
}

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

1210 1211
static inline int same_magic(const char *amagic, const char *bmagic,
			     bool has_crcs)
L
Linus Torvalds 已提交
1212 1213 1214 1215 1216
{
	return strcmp(amagic, bmagic) == 0;
}
#endif /* CONFIG_MODVERSIONS */

1217
/* Resolve a symbol for this module.  I.e. if we find one, record usage. */
1218 1219
static const struct kernel_symbol *resolve_symbol(struct module *mod,
						  const struct load_info *info,
1220
						  const char *name,
1221
						  char ownername[])
L
Linus Torvalds 已提交
1222 1223
{
	struct module *owner;
1224
	const struct kernel_symbol *sym;
L
Linus Torvalds 已提交
1225
	const unsigned long *crc;
1226
	int err;
L
Linus Torvalds 已提交
1227

1228 1229 1230 1231 1232 1233
	/*
	 * The module_mutex should not be a heavily contended lock;
	 * if we get the occasional sleep here, we'll go an extra iteration
	 * in the wait_event_interruptible(), which is harmless.
	 */
	sched_annotate_sleep();
1234
	mutex_lock(&module_mutex);
1235
	sym = find_symbol(name, &owner, &crc,
A
Andi Kleen 已提交
1236
			  !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
1237 1238 1239
	if (!sym)
		goto unlock;

1240 1241
	if (!check_version(info->sechdrs, info->index.vers, name, mod, crc,
			   owner)) {
1242 1243
		sym = ERR_PTR(-EINVAL);
		goto getname;
L
Linus Torvalds 已提交
1244
	}
1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255

	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:
1256
	mutex_unlock(&module_mutex);
1257
	return sym;
L
Linus Torvalds 已提交
1258 1259
}

1260 1261 1262 1263
static const struct kernel_symbol *
resolve_symbol_wait(struct module *mod,
		    const struct load_info *info,
		    const char *name)
1264 1265
{
	const struct kernel_symbol *ksym;
1266
	char owner[MODULE_NAME_LEN];
1267 1268

	if (wait_event_interruptible_timeout(module_wq,
1269 1270
			!IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
			|| PTR_ERR(ksym) != -EBUSY,
1271
					     30 * HZ) <= 0) {
A
Andrew Morton 已提交
1272 1273
		pr_warn("%s: gave up waiting for init of module %s.\n",
			mod->name, owner);
1274 1275 1276 1277
	}
	return ksym;
}

L
Linus Torvalds 已提交
1278 1279 1280 1281
/*
 * /sys/module/foo/sections stuff
 * J. Corbet <corbet@lwn.net>
 */
R
Rusty Russell 已提交
1282
#ifdef CONFIG_SYSFS
1283

R
Rusty Russell 已提交
1284
#ifdef CONFIG_KALLSYMS
1285 1286 1287 1288 1289
static inline bool sect_empty(const Elf_Shdr *sect)
{
	return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
}

1290
struct module_sect_attr {
1291 1292 1293 1294 1295
	struct module_attribute mattr;
	char *name;
	unsigned long address;
};

1296
struct module_sect_attrs {
1297 1298 1299 1300 1301
	struct attribute_group grp;
	unsigned int nsections;
	struct module_sect_attr attrs[0];
};

L
Linus Torvalds 已提交
1302
static ssize_t module_sect_show(struct module_attribute *mattr,
1303
				struct module_kobject *mk, char *buf)
L
Linus Torvalds 已提交
1304 1305 1306
{
	struct module_sect_attr *sattr =
		container_of(mattr, struct module_sect_attr, mattr);
1307
	return sprintf(buf, "0x%pK\n", (void *)sattr->address);
L
Linus Torvalds 已提交
1308 1309
}

1310 1311
static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
{
1312
	unsigned int section;
1313 1314 1315 1316 1317 1318

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

R
Rusty Russell 已提交
1319
static void add_sect_attrs(struct module *mod, const struct load_info *info)
L
Linus Torvalds 已提交
1320 1321 1322 1323 1324
{
	unsigned int nloaded = 0, i, size[2];
	struct module_sect_attrs *sect_attrs;
	struct module_sect_attr *sattr;
	struct attribute **gattr;
D
Daniel Walker 已提交
1325

L
Linus Torvalds 已提交
1326
	/* Count loaded sections and allocate structures */
R
Rusty Russell 已提交
1327 1328
	for (i = 0; i < info->hdr->e_shnum; i++)
		if (!sect_empty(&info->sechdrs[i]))
L
Linus Torvalds 已提交
1329 1330 1331 1332 1333
			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]);
1334 1335
	sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
	if (sect_attrs == NULL)
L
Linus Torvalds 已提交
1336 1337 1338 1339 1340 1341
		return;

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

1342
	sect_attrs->nsections = 0;
L
Linus Torvalds 已提交
1343 1344
	sattr = &sect_attrs->attrs[0];
	gattr = &sect_attrs->grp.attrs[0];
R
Rusty Russell 已提交
1345 1346 1347
	for (i = 0; i < info->hdr->e_shnum; i++) {
		Elf_Shdr *sec = &info->sechdrs[i];
		if (sect_empty(sec))
1348
			continue;
R
Rusty Russell 已提交
1349 1350
		sattr->address = sec->sh_addr;
		sattr->name = kstrdup(info->secstrings + sec->sh_name,
1351 1352 1353 1354
					GFP_KERNEL);
		if (sattr->name == NULL)
			goto out;
		sect_attrs->nsections++;
1355
		sysfs_attr_init(&sattr->mattr.attr);
L
Linus Torvalds 已提交
1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369
		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:
1370
	free_sect_attrs(sect_attrs);
L
Linus Torvalds 已提交
1371 1372 1373 1374 1375 1376 1377 1378 1379
}

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. */
1380
		free_sect_attrs(mod->sect_attrs);
L
Linus Torvalds 已提交
1381 1382 1383 1384
		mod->sect_attrs = NULL;
	}
}

R
Roland McGrath 已提交
1385 1386 1387 1388 1389 1390 1391 1392 1393 1394
/*
 * /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];
};

1395
static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
R
Roland McGrath 已提交
1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412
				 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]);
1413
		kobject_put(notes_attrs->dir);
R
Roland McGrath 已提交
1414 1415 1416 1417
	}
	kfree(notes_attrs);
}

R
Rusty Russell 已提交
1418
static void add_notes_attrs(struct module *mod, const struct load_info *info)
R
Roland McGrath 已提交
1419 1420 1421 1422 1423
{
	unsigned int notes, loaded, i;
	struct module_notes_attrs *notes_attrs;
	struct bin_attribute *nattr;

1424 1425 1426 1427
	/* failed to create section attributes, so can't create notes */
	if (!mod->sect_attrs)
		return;

R
Roland McGrath 已提交
1428 1429
	/* Count notes sections and allocate structures.  */
	notes = 0;
R
Rusty Russell 已提交
1430 1431 1432
	for (i = 0; i < info->hdr->e_shnum; i++)
		if (!sect_empty(&info->sechdrs[i]) &&
		    (info->sechdrs[i].sh_type == SHT_NOTE))
R
Roland McGrath 已提交
1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445
			++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
1446 1447
	for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
		if (sect_empty(&info->sechdrs[i]))
R
Roland McGrath 已提交
1448
			continue;
R
Rusty Russell 已提交
1449
		if (info->sechdrs[i].sh_type == SHT_NOTE) {
1450
			sysfs_bin_attr_init(nattr);
R
Roland McGrath 已提交
1451 1452
			nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
			nattr->attr.mode = S_IRUGO;
R
Rusty Russell 已提交
1453 1454
			nattr->size = info->sechdrs[i].sh_size;
			nattr->private = (void *) info->sechdrs[i].sh_addr;
R
Roland McGrath 已提交
1455 1456 1457 1458 1459 1460
			nattr->read = module_notes_read;
			++nattr;
		}
		++loaded;
	}

1461
	notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
R
Roland McGrath 已提交
1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482
	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
1483
#else
1484

R
Rusty Russell 已提交
1485 1486
static inline void add_sect_attrs(struct module *mod,
				  const struct load_info *info)
L
Linus Torvalds 已提交
1487 1488 1489 1490 1491 1492
{
}

static inline void remove_sect_attrs(struct module *mod)
{
}
R
Roland McGrath 已提交
1493

R
Rusty Russell 已提交
1494 1495
static inline void add_notes_attrs(struct module *mod,
				   const struct load_info *info)
R
Roland McGrath 已提交
1496 1497 1498 1499 1500 1501
{
}

static inline void remove_notes_attrs(struct module *mod)
{
}
R
Rusty Russell 已提交
1502
#endif /* CONFIG_KALLSYMS */
L
Linus Torvalds 已提交
1503

1504 1505 1506 1507 1508 1509
static void add_usage_links(struct module *mod)
{
#ifdef CONFIG_MODULE_UNLOAD
	struct module_use *use;
	int nowarn;

1510
	mutex_lock(&module_mutex);
1511 1512 1513 1514
	list_for_each_entry(use, &mod->target_list, target_list) {
		nowarn = sysfs_create_link(use->target->holders_dir,
					   &mod->mkobj.kobj, mod->name);
	}
1515
	mutex_unlock(&module_mutex);
1516 1517 1518 1519 1520 1521 1522 1523
#endif
}

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

1524
	mutex_lock(&module_mutex);
1525 1526
	list_for_each_entry(use, &mod->target_list, target_list)
		sysfs_remove_link(use->target->holders_dir, mod->name);
1527
	mutex_unlock(&module_mutex);
1528 1529 1530
#endif
}

1531
static int module_add_modinfo_attrs(struct module *mod)
1532 1533
{
	struct module_attribute *attr;
1534
	struct module_attribute *temp_attr;
1535 1536 1537
	int error = 0;
	int i;

1538 1539 1540 1541 1542 1543 1544
	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;
1545 1546
	for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
		if (!attr->test ||
1547 1548
		    (attr->test && attr->test(mod))) {
			memcpy(temp_attr, attr, sizeof(*temp_attr));
1549
			sysfs_attr_init(&temp_attr->attr);
1550 1551
			error = sysfs_create_file(&mod->mkobj.kobj,
					&temp_attr->attr);
1552 1553
			++temp_attr;
		}
1554 1555 1556 1557
	}
	return error;
}

1558
static void module_remove_modinfo_attrs(struct module *mod)
1559 1560 1561 1562
{
	struct module_attribute *attr;
	int i;

1563 1564 1565 1566
	for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
		/* pick a field to test for end of list */
		if (!attr->attr.name)
			break;
1567
		sysfs_remove_file(&mod->mkobj.kobj, &attr->attr);
1568 1569
		if (attr->free)
			attr->free(mod);
1570
	}
1571
	kfree(mod->modinfo_attrs);
1572
}
L
Linus Torvalds 已提交
1573

1574 1575 1576 1577 1578 1579 1580 1581
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);
}

1582
static int mod_sysfs_init(struct module *mod)
L
Linus Torvalds 已提交
1583 1584
{
	int err;
1585
	struct kobject *kobj;
L
Linus Torvalds 已提交
1586

1587
	if (!module_sysfs_initialized) {
A
Andrew Morton 已提交
1588
		pr_err("%s: module sysfs not initialized\n", mod->name);
1589 1590 1591
		err = -EINVAL;
		goto out;
	}
1592 1593 1594

	kobj = kset_find_obj(module_kset, mod->name);
	if (kobj) {
A
Andrew Morton 已提交
1595
		pr_err("%s: module is already loaded\n", mod->name);
1596 1597 1598 1599 1600
		kobject_put(kobj);
		err = -EINVAL;
		goto out;
	}

L
Linus Torvalds 已提交
1601
	mod->mkobj.mod = mod;
1602

1603 1604 1605 1606 1607
	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)
1608
		mod_kobject_put(mod);
K
Kay Sievers 已提交
1609

1610
	/* delay uevent until full sysfs population */
K
Kay Sievers 已提交
1611 1612 1613 1614
out:
	return err;
}

1615
static int mod_sysfs_setup(struct module *mod,
R
Rusty Russell 已提交
1616
			   const struct load_info *info,
K
Kay Sievers 已提交
1617 1618 1619 1620 1621
			   struct kernel_param *kparam,
			   unsigned int num_params)
{
	int err;

1622 1623 1624 1625
	err = mod_sysfs_init(mod);
	if (err)
		goto out;

1626
	mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1627 1628
	if (!mod->holders_dir) {
		err = -ENOMEM;
K
Kay Sievers 已提交
1629
		goto out_unreg;
1630
	}
K
Kay Sievers 已提交
1631

L
Linus Torvalds 已提交
1632 1633
	err = module_param_sysfs_setup(mod, kparam, num_params);
	if (err)
K
Kay Sievers 已提交
1634
		goto out_unreg_holders;
L
Linus Torvalds 已提交
1635

1636 1637
	err = module_add_modinfo_attrs(mod);
	if (err)
1638
		goto out_unreg_param;
1639

1640
	add_usage_links(mod);
R
Rusty Russell 已提交
1641 1642
	add_sect_attrs(mod, info);
	add_notes_attrs(mod, info);
1643

1644
	kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
L
Linus Torvalds 已提交
1645 1646
	return 0;

1647 1648
out_unreg_param:
	module_param_sysfs_remove(mod);
K
Kay Sievers 已提交
1649
out_unreg_holders:
1650
	kobject_put(mod->holders_dir);
K
Kay Sievers 已提交
1651
out_unreg:
1652
	mod_kobject_put(mod);
1653
out:
L
Linus Torvalds 已提交
1654 1655
	return err;
}
1656 1657 1658

static void mod_sysfs_fini(struct module *mod)
{
R
Rusty Russell 已提交
1659 1660
	remove_notes_attrs(mod);
	remove_sect_attrs(mod);
1661
	mod_kobject_put(mod);
1662 1663
}

R
Rusty Russell 已提交
1664
#else /* !CONFIG_SYSFS */
1665

R
Rusty Russell 已提交
1666 1667
static int mod_sysfs_setup(struct module *mod,
			   const struct load_info *info,
1668 1669 1670 1671 1672 1673
			   struct kernel_param *kparam,
			   unsigned int num_params)
{
	return 0;
}

1674 1675 1676 1677
static void mod_sysfs_fini(struct module *mod)
{
}

1678 1679 1680 1681
static void module_remove_modinfo_attrs(struct module *mod)
{
}

1682 1683 1684 1685
static void del_usage_links(struct module *mod)
{
}

1686
#endif /* CONFIG_SYSFS */
L
Linus Torvalds 已提交
1687

1688
static void mod_sysfs_teardown(struct module *mod)
L
Linus Torvalds 已提交
1689
{
1690
	del_usage_links(mod);
1691
	module_remove_modinfo_attrs(mod);
L
Linus Torvalds 已提交
1692
	module_param_sysfs_remove(mod);
1693 1694
	kobject_put(mod->mkobj.drivers_dir);
	kobject_put(mod->holders_dir);
1695
	mod_sysfs_fini(mod);
L
Linus Torvalds 已提交
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 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741
#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);
	}
}

1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759
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);
1760 1761 1762
}

/* Iterate through all modules and set each module's text as RW */
1763
void set_all_modules_text_rw(void)
1764 1765 1766 1767 1768
{
	struct module *mod;

	mutex_lock(&module_mutex);
	list_for_each_entry_rcu(mod, &modules, list) {
1769 1770
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785
		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 */
1786
void set_all_modules_text_ro(void)
1787 1788 1789 1790 1791
{
	struct module *mod;

	mutex_lock(&module_mutex);
	list_for_each_entry_rcu(mod, &modules, list) {
1792 1793
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808
		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) { }
1809 1810
static void unset_module_core_ro_nx(struct module *mod) { }
static void unset_module_init_ro_nx(struct module *mod) { }
1811 1812
#endif

1813
void __weak module_memfree(void *module_region)
1814 1815 1816 1817 1818 1819 1820 1821
{
	vfree(module_region);
}

void __weak module_arch_cleanup(struct module *mod)
{
}

1822 1823 1824 1825
void __weak module_arch_freeing_init(struct module *mod)
{
}

1826
/* Free a module, remove from lists, etc. */
L
Linus Torvalds 已提交
1827 1828
static void free_module(struct module *mod)
{
1829 1830
	trace_module_free(mod);

1831
	mod_sysfs_teardown(mod);
L
Linus Torvalds 已提交
1832

1833 1834
	/* We leave it in list to prevent duplicate loads, but make sure
	 * that noone uses it while it's being deconstructed. */
1835
	mutex_lock(&module_mutex);
1836
	mod->state = MODULE_STATE_UNFORMED;
1837
	mutex_unlock(&module_mutex);
1838

1839 1840 1841
	/* Remove dynamic debug info */
	ddebug_remove_module(mod->name);

L
Linus Torvalds 已提交
1842 1843 1844 1845 1846 1847
	/* Arch-specific cleanup. */
	module_arch_cleanup(mod);

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

1848 1849 1850
	/* Free any allocated parameters. */
	destroy_params(mod->kp, mod->num_kp);

1851 1852
	/* Now we can delete it from the lists */
	mutex_lock(&module_mutex);
1853 1854
	/* Unlink carefully: kallsyms could be walking list. */
	list_del_rcu(&mod->list);
1855
	/* Remove this module from bug list, this uses list_del_rcu */
1856
	module_bug_cleanup(mod);
1857 1858
	/* Wait for RCU synchronizing before releasing mod->list and buglist. */
	synchronize_rcu();
1859 1860
	mutex_unlock(&module_mutex);

L
Linus Torvalds 已提交
1861
	/* This may be NULL, but that's OK */
1862
	unset_module_init_ro_nx(mod);
1863
	module_arch_freeing_init(mod);
1864
	module_memfree(mod->module_init);
L
Linus Torvalds 已提交
1865
	kfree(mod->args);
1866
	percpu_modfree(mod);
1867

1868
	/* Free lock-classes; relies on the preceding sync_rcu(). */
I
Ingo Molnar 已提交
1869 1870
	lockdep_free_key_range(mod->module_core, mod->core_size);

L
Linus Torvalds 已提交
1871
	/* Finally, free the core (containing the module structure) */
1872
	unset_module_core_ro_nx(mod);
1873
	module_memfree(mod->module_core);
1874 1875 1876 1877

#ifdef CONFIG_MPU
	update_protections(current->mm);
#endif
L
Linus Torvalds 已提交
1878 1879 1880 1881 1882
}

void *__symbol_get(const char *symbol)
{
	struct module *owner;
1883
	const struct kernel_symbol *sym;
L
Linus Torvalds 已提交
1884

R
Rusty Russell 已提交
1885
	preempt_disable();
1886 1887 1888
	sym = find_symbol(symbol, &owner, NULL, true, true);
	if (sym && strong_try_module_get(owner))
		sym = NULL;
R
Rusty Russell 已提交
1889
	preempt_enable();
L
Linus Torvalds 已提交
1890

1891
	return sym ? (void *)sym->value : NULL;
L
Linus Torvalds 已提交
1892 1893 1894
}
EXPORT_SYMBOL_GPL(__symbol_get);

1895 1896
/*
 * Ensure that an exported symbol [global namespace] does not already exist
1897
 * in the kernel or in some other module's exported symbol table.
1898 1899
 *
 * You must hold the module_mutex.
1900 1901 1902
 */
static int verify_export_symbols(struct module *mod)
{
1903
	unsigned int i;
1904
	struct module *owner;
1905 1906 1907 1908 1909 1910 1911 1912
	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 },
1913
#ifdef CONFIG_UNUSED_SYMBOLS
1914 1915
		{ mod->unused_syms, mod->num_unused_syms },
		{ mod->unused_gpl_syms, mod->num_unused_gpl_syms },
1916
#endif
1917
	};
1918

1919 1920
	for (i = 0; i < ARRAY_SIZE(arr); i++) {
		for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
1921
			if (find_symbol(s->name, &owner, NULL, true, false)) {
A
Andrew Morton 已提交
1922
				pr_err("%s: exports duplicate symbol %s"
1923 1924 1925 1926
				       " (owned by %s)\n",
				       mod->name, s->name, module_name(owner));
				return -ENOEXEC;
			}
1927
		}
1928 1929
	}
	return 0;
1930 1931
}

1932
/* Change all symbols so that st_value encodes the pointer directly. */
1933 1934 1935 1936
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
1937
	unsigned long secbase;
1938
	unsigned int i;
L
Linus Torvalds 已提交
1939
	int ret = 0;
1940
	const struct kernel_symbol *ksym;
L
Linus Torvalds 已提交
1941

1942 1943 1944
	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
1945 1946
		switch (sym[i].st_shndx) {
		case SHN_COMMON:
1947 1948 1949 1950
			/* Ignore common symbols */
			if (!strncmp(name, "__gnu_lto", 9))
				break;

L
Linus Torvalds 已提交
1951 1952
			/* We compiled with -fno-common.  These are not
			   supposed to happen.  */
1953
			pr_debug("Common symbol: %s\n", name);
1954
			pr_warn("%s: please compile with -fno-common\n",
L
Linus Torvalds 已提交
1955 1956 1957 1958 1959 1960
			       mod->name);
			ret = -ENOEXEC;
			break;

		case SHN_ABS:
			/* Don't need to do anything */
1961
			pr_debug("Absolute symbol: 0x%08lx\n",
L
Linus Torvalds 已提交
1962 1963 1964 1965
			       (long)sym[i].st_value);
			break;

		case SHN_UNDEF:
1966
			ksym = resolve_symbol_wait(mod, info, name);
L
Linus Torvalds 已提交
1967
			/* Ok if resolved.  */
1968
			if (ksym && !IS_ERR(ksym)) {
1969
				sym[i].st_value = ksym->value;
L
Linus Torvalds 已提交
1970
				break;
1971 1972
			}

L
Linus Torvalds 已提交
1973
			/* Ok if weak.  */
1974
			if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
L
Linus Torvalds 已提交
1975 1976
				break;

A
Andrew Morton 已提交
1977 1978
			pr_warn("%s: Unknown symbol %s (err %li)\n",
				mod->name, name, PTR_ERR(ksym));
1979
			ret = PTR_ERR(ksym) ?: -ENOENT;
L
Linus Torvalds 已提交
1980 1981 1982 1983
			break;

		default:
			/* Divert to percpu allocation if a percpu var. */
1984
			if (sym[i].st_shndx == info->index.pcpu)
1985
				secbase = (unsigned long)mod_percpu(mod);
L
Linus Torvalds 已提交
1986
			else
1987
				secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
L
Linus Torvalds 已提交
1988 1989 1990 1991 1992 1993 1994 1995
			sym[i].st_value += secbase;
			break;
		}
	}

	return ret;
}

1996
static int apply_relocations(struct module *mod, const struct load_info *info)
1997 1998 1999 2000 2001
{
	unsigned int i;
	int err = 0;

	/* Now do relocations. */
2002 2003
	for (i = 1; i < info->hdr->e_shnum; i++) {
		unsigned int infosec = info->sechdrs[i].sh_info;
2004 2005

		/* Not a valid relocation section? */
2006
		if (infosec >= info->hdr->e_shnum)
2007 2008 2009
			continue;

		/* Don't bother with non-allocated sections */
2010
		if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
2011 2012
			continue;

2013 2014 2015 2016 2017 2018
		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);
2019 2020 2021 2022 2023 2024
		if (err < 0)
			break;
	}
	return err;
}

2025 2026 2027 2028 2029 2030 2031 2032
/* 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
2033
/* Update size with this section: return offset. */
2034 2035
static long get_offset(struct module *mod, unsigned int *size,
		       Elf_Shdr *sechdr, unsigned int section)
L
Linus Torvalds 已提交
2036 2037 2038
{
	long ret;

2039
	*size += arch_mod_section_prepend(mod, section);
L
Linus Torvalds 已提交
2040 2041 2042 2043 2044 2045 2046 2047 2048
	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. */
2049
static void layout_sections(struct module *mod, struct load_info *info)
L
Linus Torvalds 已提交
2050 2051 2052 2053 2054 2055 2056 2057 2058 2059 2060 2061
{
	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;

2062 2063
	for (i = 0; i < info->hdr->e_shnum; i++)
		info->sechdrs[i].sh_entsize = ~0UL;
L
Linus Torvalds 已提交
2064

2065
	pr_debug("Core section allocation order:\n");
L
Linus Torvalds 已提交
2066
	for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2067 2068 2069
		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
2070 2071 2072 2073

			if ((s->sh_flags & masks[m][0]) != masks[m][0]
			    || (s->sh_flags & masks[m][1])
			    || s->sh_entsize != ~0UL
2074
			    || strstarts(sname, ".init"))
L
Linus Torvalds 已提交
2075
				continue;
2076
			s->sh_entsize = get_offset(mod, &mod->core_size, s, i);
2077
			pr_debug("\t%s\n", sname);
L
Linus Torvalds 已提交
2078
		}
2079 2080 2081
		switch (m) {
		case 0: /* executable */
			mod->core_size = debug_align(mod->core_size);
L
Linus Torvalds 已提交
2082
			mod->core_text_size = mod->core_size;
2083 2084 2085 2086 2087 2088 2089 2090 2091
			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
2092 2093
	}

2094
	pr_debug("Init section allocation order:\n");
L
Linus Torvalds 已提交
2095
	for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2096 2097 2098
		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
2099 2100 2101 2102

			if ((s->sh_flags & masks[m][0]) != masks[m][0]
			    || (s->sh_flags & masks[m][1])
			    || s->sh_entsize != ~0UL
2103
			    || !strstarts(sname, ".init"))
L
Linus Torvalds 已提交
2104
				continue;
2105
			s->sh_entsize = (get_offset(mod, &mod->init_size, s, i)
L
Linus Torvalds 已提交
2106
					 | INIT_OFFSET_MASK);
2107
			pr_debug("\t%s\n", sname);
L
Linus Torvalds 已提交
2108
		}
2109 2110 2111
		switch (m) {
		case 0: /* executable */
			mod->init_size = debug_align(mod->init_size);
L
Linus Torvalds 已提交
2112
			mod->init_text_size = mod->init_size;
2113 2114 2115 2116 2117 2118 2119 2120 2121
			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
2122 2123 2124 2125 2126 2127 2128 2129
	}
}

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

2130
	if (!license_is_gpl_compatible(license)) {
A
Andi Kleen 已提交
2131
		if (!test_taint(TAINT_PROPRIETARY_MODULE))
A
Andrew Morton 已提交
2132 2133
			pr_warn("%s: module license '%s' taints kernel.\n",
				mod->name, license);
2134 2135
		add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
				 LOCKDEP_NOW_UNRELIABLE);
L
Linus Torvalds 已提交
2136 2137 2138 2139 2140 2141 2142 2143 2144 2145 2146 2147 2148 2149 2150 2151 2152 2153 2154 2155 2156 2157
	}
}

/* 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;
}

2158
static char *get_modinfo(struct load_info *info, const char *tag)
L
Linus Torvalds 已提交
2159 2160 2161
{
	char *p;
	unsigned int taglen = strlen(tag);
2162 2163
	Elf_Shdr *infosec = &info->sechdrs[info->index.info];
	unsigned long size = infosec->sh_size;
L
Linus Torvalds 已提交
2164

2165
	for (p = (char *)infosec->sh_addr; p; p = next_string(p, &size)) {
L
Linus Torvalds 已提交
2166 2167 2168 2169 2170 2171
		if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
			return p + taglen + 1;
	}
	return NULL;
}

2172
static void setup_modinfo(struct module *mod, struct load_info *info)
2173 2174 2175 2176 2177 2178
{
	struct module_attribute *attr;
	int i;

	for (i = 0; (attr = modinfo_attrs[i]); i++) {
		if (attr->setup)
2179
			attr->setup(mod, get_modinfo(info, attr->attr.name));
2180 2181 2182
	}
}

2183 2184 2185 2186 2187 2188 2189 2190 2191 2192 2193
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
2194
#ifdef CONFIG_KALLSYMS
2195 2196 2197 2198 2199 2200

/* 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)
{
2201 2202
	return bsearch(name, start, stop - start,
			sizeof(struct kernel_symbol), cmp_name);
2203 2204
}

2205 2206
static int is_exported(const char *name, unsigned long value,
		       const struct module *mod)
L
Linus Torvalds 已提交
2207
{
2208 2209 2210
	const struct kernel_symbol *ks;
	if (!mod)
		ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
2211
	else
2212 2213
		ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
	return ks != NULL && ks->value == value;
L
Linus Torvalds 已提交
2214 2215 2216
}

/* As per nm */
2217
static char elf_type(const Elf_Sym *sym, const struct load_info *info)
L
Linus Torvalds 已提交
2218
{
2219 2220
	const Elf_Shdr *sechdrs = info->sechdrs;

L
Linus Torvalds 已提交
2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240 2241 2242 2243 2244 2245 2246 2247 2248 2249
	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';
	}
2250 2251
	if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
		      ".debug")) {
L
Linus Torvalds 已提交
2252
		return 'n';
2253
	}
L
Linus Torvalds 已提交
2254 2255 2256
	return '?';
}

2257
static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
2258
			unsigned int shnum)
2259 2260 2261 2262 2263 2264 2265 2266 2267 2268 2269 2270 2271 2272 2273 2274 2275 2276 2277
{
	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;
}

2278 2279 2280 2281 2282 2283 2284
/*
 * 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>.
 */
2285
static void layout_symtab(struct module *mod, struct load_info *info)
2286
{
2287 2288
	Elf_Shdr *symsect = info->sechdrs + info->index.sym;
	Elf_Shdr *strsect = info->sechdrs + info->index.str;
2289
	const Elf_Sym *src;
2290
	unsigned int i, nsrc, ndst, strtab_size = 0;
2291 2292 2293 2294

	/* 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,
2295
					 info->index.sym) | INIT_OFFSET_MASK;
2296
	pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
2297

2298
	src = (void *)info->hdr + symsect->sh_offset;
2299
	nsrc = symsect->sh_size / sizeof(*src);
2300

2301
	/* Compute total space required for the core symbols' strtab. */
2302 2303 2304 2305
	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;
2306
			ndst++;
2307
		}
2308
	}
2309 2310

	/* Append room for core symbols at end of core part. */
2311
	info->symoffs = ALIGN(mod->core_size, symsect->sh_addralign ?: 1);
2312 2313
	info->stroffs = mod->core_size = info->symoffs + ndst * sizeof(Elf_Sym);
	mod->core_size += strtab_size;
2314
	mod->core_size = debug_align(mod->core_size);
2315

2316 2317 2318
	/* 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,
2319
					 info->index.str) | INIT_OFFSET_MASK;
2320
	mod->init_size = debug_align(mod->init_size);
2321
	pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
2322 2323
}

2324
static void add_kallsyms(struct module *mod, const struct load_info *info)
L
Linus Torvalds 已提交
2325
{
2326 2327 2328
	unsigned int i, ndst;
	const Elf_Sym *src;
	Elf_Sym *dst;
2329
	char *s;
2330
	Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
L
Linus Torvalds 已提交
2331

2332 2333
	mod->symtab = (void *)symsec->sh_addr;
	mod->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
2334 2335
	/* 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
2336 2337 2338

	/* Set types up while we still have access to sections. */
	for (i = 0; i < mod->num_symtab; i++)
2339
		mod->symtab[i].st_info = elf_type(&mod->symtab[i], info);
2340

R
Rusty Russell 已提交
2341
	mod->core_symtab = dst = mod->module_core + info->symoffs;
2342
	mod->core_strtab = s = mod->module_core + info->stroffs;
2343
	src = mod->symtab;
2344 2345 2346 2347 2348 2349 2350 2351
	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;
		}
2352 2353
	}
	mod->core_num_syms = ndst;
L
Linus Torvalds 已提交
2354 2355
}
#else
2356
static inline void layout_symtab(struct module *mod, struct load_info *info)
2357 2358
{
}
2359

2360
static void add_kallsyms(struct module *mod, const struct load_info *info)
L
Linus Torvalds 已提交
2361 2362 2363 2364
{
}
#endif /* CONFIG_KALLSYMS */

2365
static void dynamic_debug_setup(struct _ddebug *debug, unsigned int num)
2366
{
2367 2368
	if (!debug)
		return;
2369 2370
#ifdef CONFIG_DYNAMIC_DEBUG
	if (ddebug_add_module(debug, num, debug->modname))
A
Andrew Morton 已提交
2371 2372
		pr_err("dynamic debug error adding module: %s\n",
			debug->modname);
2373
#endif
R
Rusty Russell 已提交
2374
}
2375

2376 2377 2378 2379 2380 2381
static void dynamic_debug_remove(struct _ddebug *debug)
{
	if (debug)
		ddebug_remove_module(debug->modname);
}

2382 2383
void * __weak module_alloc(unsigned long size)
{
R
Rusty Russell 已提交
2384
	return vmalloc_exec(size);
2385 2386
}

2387 2388 2389 2390 2391
static void *module_alloc_update_bounds(unsigned long size)
{
	void *ret = module_alloc(size);

	if (ret) {
2392
		mutex_lock(&module_mutex);
2393 2394 2395 2396 2397
		/* 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;
2398
		mutex_unlock(&module_mutex);
2399 2400 2401 2402
	}
	return ret;
}

C
Catalin Marinas 已提交
2403
#ifdef CONFIG_DEBUG_KMEMLEAK
2404 2405
static void kmemleak_load_module(const struct module *mod,
				 const struct load_info *info)
C
Catalin Marinas 已提交
2406 2407 2408 2409
{
	unsigned int i;

	/* only scan the sections containing data */
2410
	kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
C
Catalin Marinas 已提交
2411

2412
	for (i = 1; i < info->hdr->e_shnum; i++) {
2413 2414 2415 2416
		/* 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))
C
Catalin Marinas 已提交
2417 2418
			continue;

2419 2420
		kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
				   info->sechdrs[i].sh_size, GFP_KERNEL);
C
Catalin Marinas 已提交
2421 2422 2423
	}
}
#else
2424 2425
static inline void kmemleak_load_module(const struct module *mod,
					const struct load_info *info)
C
Catalin Marinas 已提交
2426 2427 2428 2429
{
}
#endif

R
Rusty Russell 已提交
2430
#ifdef CONFIG_MODULE_SIG
2431
static int module_sig_check(struct load_info *info)
R
Rusty Russell 已提交
2432 2433
{
	int err = -ENOKEY;
2434 2435
	const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
	const void *mod = info->hdr;
2436

2437 2438
	if (info->len > markerlen &&
	    memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
2439
		/* We truncate the module to discard the signature */
2440 2441
		info->len -= markerlen;
		err = mod_verify_sig(mod, &info->len);
R
Rusty Russell 已提交
2442 2443 2444 2445 2446 2447 2448 2449 2450 2451 2452 2453 2454 2455
	}

	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 */
2456
static int module_sig_check(struct load_info *info)
R
Rusty Russell 已提交
2457 2458 2459 2460 2461
{
	return 0;
}
#endif /* !CONFIG_MODULE_SIG */

2462 2463
/* Sanity checks against invalid binaries, wrong arch, weird elf version. */
static int elf_header_check(struct load_info *info)
2464
{
2465 2466 2467 2468 2469 2470 2471 2472 2473 2474 2475 2476 2477
	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;
2478

2479 2480 2481 2482 2483 2484
	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)
2485 2486 2487
{
	int err;

2488 2489
	info->len = len;
	if (info->len < sizeof(*(info->hdr)))
2490 2491
		return -ENOEXEC;

2492 2493 2494 2495
	err = security_kernel_module_from_file(NULL);
	if (err)
		return err;

2496
	/* Suck in entire file: we'll want most of it. */
2497 2498
	info->hdr = vmalloc(info->len);
	if (!info->hdr)
2499 2500
		return -ENOMEM;

2501 2502 2503
	if (copy_from_user(info->hdr, umod, info->len) != 0) {
		vfree(info->hdr);
		return -EFAULT;
2504 2505
	}

2506 2507 2508 2509 2510 2511
	return 0;
}

/* Sets info->hdr and info->len. */
static int copy_module_from_fd(int fd, struct load_info *info)
{
A
Al Viro 已提交
2512
	struct fd f = fdget(fd);
2513 2514 2515 2516 2517
	int err;
	struct kstat stat;
	loff_t pos;
	ssize_t bytes = 0;

A
Al Viro 已提交
2518
	if (!f.file)
2519 2520
		return -ENOEXEC;

A
Al Viro 已提交
2521
	err = security_kernel_module_from_file(f.file);
R
Rusty Russell 已提交
2522
	if (err)
2523
		goto out;
R
Rusty Russell 已提交
2524

A
Al Viro 已提交
2525
	err = vfs_getattr(&f.file->f_path, &stat);
R
Rusty Russell 已提交
2526
	if (err)
2527
		goto out;
2528

2529 2530 2531
	if (stat.size > INT_MAX) {
		err = -EFBIG;
		goto out;
2532
	}
2533 2534 2535 2536 2537 2538 2539

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

2540 2541 2542 2543
	info->hdr = vmalloc(stat.size);
	if (!info->hdr) {
		err = -ENOMEM;
		goto out;
2544
	}
R
Rusty Russell 已提交
2545

2546 2547
	pos = 0;
	while (pos < stat.size) {
A
Al Viro 已提交
2548
		bytes = kernel_read(f.file, pos, (char *)(info->hdr) + pos,
2549 2550 2551 2552 2553 2554 2555 2556 2557 2558 2559
				    stat.size - pos);
		if (bytes < 0) {
			vfree(info->hdr);
			err = bytes;
			goto out;
		}
		if (bytes == 0)
			break;
		pos += bytes;
	}
	info->len = pos;
2560

2561
out:
A
Al Viro 已提交
2562
	fdput(f);
2563 2564 2565
	return err;
}

R
Rusty Russell 已提交
2566 2567 2568 2569 2570
static void free_copy(struct load_info *info)
{
	vfree(info->hdr);
}

2571
static int rewrite_section_headers(struct load_info *info, int flags)
2572 2573 2574 2575 2576 2577 2578 2579 2580 2581
{
	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) {
A
Andrew Morton 已提交
2582
			pr_err("Module len %lu truncated\n", info->len);
2583 2584 2585 2586 2587 2588 2589 2590 2591 2592 2593 2594 2595
			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
	}
2596 2597

	/* Track but don't keep modinfo and version sections. */
2598 2599 2600 2601
	if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
		info->index.vers = 0; /* Pretend no __versions section! */
	else
		info->index.vers = find_sec(info, "__versions");
2602
	info->index.info = find_sec(info, ".modinfo");
2603 2604
	info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
	info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
2605 2606 2607
	return 0;
}

L
Linus Torvalds 已提交
2608 2609 2610 2611 2612 2613 2614 2615
/*
 * 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).
 */
2616
static struct module *setup_load_info(struct load_info *info, int flags)
L
Linus Torvalds 已提交
2617 2618
{
	unsigned int i;
2619
	int err;
L
Linus Torvalds 已提交
2620 2621 2622 2623
	struct module *mod;

	/* Set up the convenience variables */
	info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
2624 2625
	info->secstrings = (void *)info->hdr
		+ info->sechdrs[info->hdr->e_shstrndx].sh_offset;
L
Linus Torvalds 已提交
2626

2627
	err = rewrite_section_headers(info, flags);
2628 2629
	if (err)
		return ERR_PTR(err);
L
Linus Torvalds 已提交
2630

2631 2632
	/* Find internal symbols and strings. */
	for (i = 1; i < info->hdr->e_shnum; i++) {
L
Linus Torvalds 已提交
2633 2634 2635
		if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
			info->index.sym = i;
			info->index.str = info->sechdrs[i].sh_link;
2636 2637 2638
			info->strtab = (char *)info->hdr
				+ info->sechdrs[info->index.str].sh_offset;
			break;
L
Linus Torvalds 已提交
2639 2640 2641
		}
	}

2642
	info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
L
Linus Torvalds 已提交
2643
	if (!info->index.mod) {
A
Andrew Morton 已提交
2644
		pr_warn("No module found in object\n");
L
Linus Torvalds 已提交
2645 2646 2647 2648 2649 2650
		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) {
A
Andrew Morton 已提交
2651
		pr_warn("%s: module has no symbols (stripped?)\n", mod->name);
L
Linus Torvalds 已提交
2652 2653 2654
		return ERR_PTR(-ENOEXEC);
	}

2655
	info->index.pcpu = find_pcpusec(info);
L
Linus Torvalds 已提交
2656 2657 2658 2659 2660 2661 2662 2663

	/* 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;
}

2664
static int check_modinfo(struct module *mod, struct load_info *info, int flags)
2665
{
2666
	const char *modmagic = get_modinfo(info, "vermagic");
2667 2668
	int err;

2669 2670 2671
	if (flags & MODULE_INIT_IGNORE_VERMAGIC)
		modmagic = NULL;

2672 2673 2674 2675 2676
	/* This is allowed: modprobe --force will invalidate it. */
	if (!modmagic) {
		err = try_to_force_load(mod, "bad vermagic");
		if (err)
			return err;
2677
	} else if (!same_magic(modmagic, vermagic, info->index.vers)) {
A
Andrew Morton 已提交
2678
		pr_err("%s: version magic '%s' should be '%s'\n",
2679 2680 2681 2682
		       mod->name, modmagic, vermagic);
		return -ENOEXEC;
	}

2683
	if (!get_modinfo(info, "intree"))
2684
		add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
2685

2686
	if (get_modinfo(info, "staging")) {
2687
		add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
A
Andrew Morton 已提交
2688 2689
		pr_warn("%s: module is from the staging directory, the quality "
			"is unknown, you have been warned.\n", mod->name);
2690
	}
2691 2692

	/* Set up license info based on the info section */
2693
	set_license(mod, get_modinfo(info, "license"));
2694

2695 2696 2697
	return 0;
}

2698
static int find_module_sections(struct module *mod, struct load_info *info)
L
Linus Torvalds 已提交
2699
{
2700
	mod->kp = section_objs(info, "__param",
L
Linus Torvalds 已提交
2701
			       sizeof(*mod->kp), &mod->num_kp);
2702
	mod->syms = section_objs(info, "__ksymtab",
L
Linus Torvalds 已提交
2703
				 sizeof(*mod->syms), &mod->num_syms);
2704 2705
	mod->crcs = section_addr(info, "__kcrctab");
	mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
L
Linus Torvalds 已提交
2706 2707
				     sizeof(*mod->gpl_syms),
				     &mod->num_gpl_syms);
2708 2709
	mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
	mod->gpl_future_syms = section_objs(info,
L
Linus Torvalds 已提交
2710 2711 2712
					    "__ksymtab_gpl_future",
					    sizeof(*mod->gpl_future_syms),
					    &mod->num_gpl_future_syms);
2713
	mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future");
L
Linus Torvalds 已提交
2714 2715

#ifdef CONFIG_UNUSED_SYMBOLS
2716
	mod->unused_syms = section_objs(info, "__ksymtab_unused",
L
Linus Torvalds 已提交
2717 2718
					sizeof(*mod->unused_syms),
					&mod->num_unused_syms);
2719 2720
	mod->unused_crcs = section_addr(info, "__kcrctab_unused");
	mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl",
L
Linus Torvalds 已提交
2721 2722
					    sizeof(*mod->unused_gpl_syms),
					    &mod->num_unused_gpl_syms);
2723
	mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl");
L
Linus Torvalds 已提交
2724 2725
#endif
#ifdef CONFIG_CONSTRUCTORS
2726
	mod->ctors = section_objs(info, ".ctors",
L
Linus Torvalds 已提交
2727
				  sizeof(*mod->ctors), &mod->num_ctors);
2728 2729 2730 2731 2732 2733 2734 2735
	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.
		 */
2736
		pr_warn("%s: has both .ctors and .init_array.\n",
2737 2738 2739
		       mod->name);
		return -EINVAL;
	}
L
Linus Torvalds 已提交
2740 2741 2742
#endif

#ifdef CONFIG_TRACEPOINTS
2743 2744 2745
	mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
					     sizeof(*mod->tracepoints_ptrs),
					     &mod->num_tracepoints);
L
Linus Torvalds 已提交
2746
#endif
2747 2748 2749 2750 2751
#ifdef HAVE_JUMP_LABEL
	mod->jump_entries = section_objs(info, "__jump_table",
					sizeof(*mod->jump_entries),
					&mod->num_jump_entries);
#endif
L
Linus Torvalds 已提交
2752
#ifdef CONFIG_EVENT_TRACING
2753
	mod->trace_events = section_objs(info, "_ftrace_events",
L
Linus Torvalds 已提交
2754 2755 2756
					 sizeof(*mod->trace_events),
					 &mod->num_trace_events);
#endif
2757 2758 2759 2760 2761
#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
L
Linus Torvalds 已提交
2762 2763
#ifdef CONFIG_FTRACE_MCOUNT_RECORD
	/* sechdrs[0].sh_size is always zero */
2764
	mod->ftrace_callsites = section_objs(info, "__mcount_loc",
L
Linus Torvalds 已提交
2765 2766 2767
					     sizeof(*mod->ftrace_callsites),
					     &mod->num_ftrace_callsites);
#endif
2768

2769 2770 2771
	mod->extable = section_objs(info, "__ex_table",
				    sizeof(*mod->extable), &mod->num_exentries);

2772
	if (section_addr(info, "__obsparm"))
A
Andrew Morton 已提交
2773
		pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
2774 2775 2776

	info->debug = section_objs(info, "__verbose",
				   sizeof(*info->debug), &info->num_debug);
2777 2778

	return 0;
L
Linus Torvalds 已提交
2779 2780
}

2781
static int move_module(struct module *mod, struct load_info *info)
2782 2783 2784 2785 2786 2787 2788 2789 2790 2791 2792 2793 2794
{
	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)
R
Rusty Russell 已提交
2795
		return -ENOMEM;
2796 2797 2798 2799

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

R
Rusty Russell 已提交
2800 2801 2802 2803 2804 2805 2806 2807 2808 2809
	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) {
2810
			module_memfree(mod->module_core);
R
Rusty Russell 已提交
2811 2812 2813 2814 2815 2816
			return -ENOMEM;
		}
		memset(ptr, 0, mod->init_size);
		mod->module_init = ptr;
	} else
		mod->module_init = NULL;
2817 2818

	/* Transfer each section which specifies SHF_ALLOC */
2819
	pr_debug("final section addresses:\n");
2820
	for (i = 0; i < info->hdr->e_shnum; i++) {
2821
		void *dest;
2822
		Elf_Shdr *shdr = &info->sechdrs[i];
2823

2824
		if (!(shdr->sh_flags & SHF_ALLOC))
2825 2826
			continue;

2827
		if (shdr->sh_entsize & INIT_OFFSET_MASK)
2828
			dest = mod->module_init
2829
				+ (shdr->sh_entsize & ~INIT_OFFSET_MASK);
2830
		else
2831
			dest = mod->module_core + shdr->sh_entsize;
2832

2833 2834
		if (shdr->sh_type != SHT_NOBITS)
			memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
2835
		/* Update sh_addr to point to copy in image. */
2836
		shdr->sh_addr = (unsigned long)dest;
2837 2838
		pr_debug("\t0x%lx %s\n",
			 (long)shdr->sh_addr, info->secstrings + shdr->sh_name);
2839
	}
R
Rusty Russell 已提交
2840 2841

	return 0;
2842 2843
}

2844
static int check_module_license_and_versions(struct module *mod)
2845 2846 2847 2848 2849 2850 2851
{
	/*
	 * 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)
2852
		add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
2853 2854 2855

	/* driverloader was caught wrongly pretending to be under GPL */
	if (strcmp(mod->name, "driverloader") == 0)
2856 2857
		add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
				 LOCKDEP_NOW_UNRELIABLE);
2858

2859 2860
	/* lve claims to be GPL but upstream won't provide source */
	if (strcmp(mod->name, "lve") == 0)
2861 2862
		add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
				 LOCKDEP_NOW_UNRELIABLE);
2863

2864 2865 2866 2867 2868 2869 2870 2871 2872 2873 2874 2875 2876 2877 2878 2879 2880 2881 2882 2883 2884 2885 2886 2887 2888 2889 2890 2891 2892 2893 2894 2895 2896 2897 2898 2899 2900 2901 2902
#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);
}

2903 2904 2905 2906 2907 2908 2909 2910
int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
				     Elf_Shdr *sechdrs,
				     char *secstrings,
				     struct module *mod)
{
	return 0;
}

2911
static struct module *layout_and_allocate(struct load_info *info, int flags)
L
Linus Torvalds 已提交
2912
{
R
Rusty Russell 已提交
2913
	/* Module within temporary copy. */
L
Linus Torvalds 已提交
2914
	struct module *mod;
R
Rusty Russell 已提交
2915
	int err;
2916

2917
	mod = setup_load_info(info, flags);
R
Rusty Russell 已提交
2918 2919
	if (IS_ERR(mod))
		return mod;
L
Linus Torvalds 已提交
2920

2921
	err = check_modinfo(mod, info, flags);
2922 2923
	if (err)
		return ERR_PTR(err);
L
Linus Torvalds 已提交
2924 2925

	/* Allow arches to frob section contents and sizes.  */
2926 2927
	err = module_frob_arch_sections(info->hdr, info->sechdrs,
					info->secstrings, mod);
L
Linus Torvalds 已提交
2928
	if (err < 0)
2929
		return ERR_PTR(err);
L
Linus Torvalds 已提交
2930

2931 2932
	/* 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
2933 2934 2935 2936

	/* 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. */
2937 2938
	layout_sections(mod, info);
	layout_symtab(mod, info);
L
Linus Torvalds 已提交
2939

2940
	/* Allocate and move to the final place */
2941
	err = move_module(mod, info);
R
Rusty Russell 已提交
2942
	if (err)
2943
		return ERR_PTR(err);
R
Rusty Russell 已提交
2944 2945 2946

	/* Module has been copied to its final place now: return it. */
	mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2947
	kmemleak_load_module(mod, info);
R
Rusty Russell 已提交
2948 2949 2950 2951 2952 2953 2954
	return mod;
}

/* mod is no longer valid after this! */
static void module_deallocate(struct module *mod, struct load_info *info)
{
	percpu_modfree(mod);
2955
	module_arch_freeing_init(mod);
2956 2957
	module_memfree(mod->module_init);
	module_memfree(mod->module_core);
R
Rusty Russell 已提交
2958 2959
}

2960 2961 2962 2963 2964 2965 2966
int __weak module_finalize(const Elf_Ehdr *hdr,
			   const Elf_Shdr *sechdrs,
			   struct module *me)
{
	return 0;
}

2967 2968
static int post_relocation(struct module *mod, const struct load_info *info)
{
2969
	/* Sort exception table now relocations are done. */
2970 2971 2972 2973 2974 2975
	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);

2976
	/* Setup kallsyms-specific fields. */
2977 2978 2979 2980 2981 2982
	add_kallsyms(mod, info);

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

2983 2984 2985 2986 2987 2988
/* Is this module of this name done loading?  No locks held. */
static bool finished_loading(const char *name)
{
	struct module *mod;
	bool ret;

2989 2990 2991 2992 2993 2994
	/*
	 * The module_mutex should not be a heavily contended lock;
	 * if we get the occasional sleep here, we'll go an extra iteration
	 * in the wait_event_interruptible(), which is harmless.
	 */
	sched_annotate_sleep();
2995
	mutex_lock(&module_mutex);
2996
	mod = find_module_all(name, strlen(name), true);
2997 2998
	ret = !mod || mod->state == MODULE_STATE_LIVE
		|| mod->state == MODULE_STATE_GOING;
2999 3000 3001 3002 3003
	mutex_unlock(&module_mutex);

	return ret;
}

3004 3005 3006 3007 3008 3009 3010 3011 3012 3013 3014
/* 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
}

3015 3016 3017 3018 3019 3020 3021 3022 3023 3024 3025 3026 3027
/* For freeing module_init on success, in case kallsyms traversing */
struct mod_initfree {
	struct rcu_head rcu;
	void *module_init;
};

static void do_free_init(struct rcu_head *head)
{
	struct mod_initfree *m = container_of(head, struct mod_initfree, rcu);
	module_memfree(m->module_init);
	kfree(m);
}

3028 3029 3030 3031 3032 3033 3034
/*
 * This is where the real work happens.
 *
 * Keep it uninlined to provide a reliable breakpoint target, e.g. for the gdb
 * helper command 'lx-symbols'.
 */
static noinline int do_init_module(struct module *mod)
3035 3036
{
	int ret = 0;
3037 3038 3039 3040 3041 3042 3043 3044
	struct mod_initfree *freeinit;

	freeinit = kmalloc(sizeof(*freeinit), GFP_KERNEL);
	if (!freeinit) {
		ret = -ENOMEM;
		goto fail;
	}
	freeinit->module_init = mod->module_init;
3045

3046 3047 3048 3049 3050 3051
	/*
	 * 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;

3052 3053 3054 3055 3056
	do_mod_ctors(mod);
	/* Start the module */
	if (mod->init != NULL)
		ret = do_one_initcall(mod->init);
	if (ret < 0) {
3057
		goto fail_free_freeinit;
3058 3059
	}
	if (ret > 0) {
A
Andrew Morton 已提交
3060 3061 3062 3063
		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__);
3064 3065 3066 3067 3068 3069 3070 3071
		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);

3072 3073 3074 3075 3076 3077 3078 3079 3080 3081 3082 3083 3084 3085 3086 3087 3088 3089 3090
	/*
	 * 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();
3091 3092 3093 3094 3095 3096 3097 3098 3099 3100 3101

	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);
3102
	module_arch_freeing_init(mod);
3103 3104 3105 3106
	mod->module_init = NULL;
	mod->init_size = 0;
	mod->init_ro_size = 0;
	mod->init_text_size = 0;
3107 3108 3109 3110 3111 3112 3113
	/*
	 * We want to free module_init, but be aware that kallsyms may be
	 * walking this with preempt disabled.  In all the failure paths,
	 * we call synchronize_rcu/synchronize_sched, but we don't want
	 * to slow down the success path, so use actual RCU here.
	 */
	call_rcu(&freeinit->rcu, do_free_init);
3114 3115 3116 3117
	mutex_unlock(&module_mutex);
	wake_up_all(&module_wq);

	return 0;
3118 3119 3120 3121 3122 3123 3124 3125 3126 3127 3128 3129 3130

fail_free_freeinit:
	kfree(freeinit);
fail:
	/* 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;
3131 3132 3133 3134 3135 3136 3137 3138 3139 3140
}

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

	return 0;
}

3141 3142 3143 3144 3145 3146 3147 3148 3149 3150 3151 3152 3153 3154
/*
 * 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);
3155 3156
	old = find_module_all(mod->name, strlen(mod->name), true);
	if (old != NULL) {
3157 3158 3159 3160
		if (old->state == MODULE_STATE_COMING
		    || old->state == MODULE_STATE_UNFORMED) {
			/* Wait in case it fails to load. */
			mutex_unlock(&module_mutex);
3161 3162
			err = wait_event_interruptible(module_wq,
					       finished_loading(mod->name));
3163 3164 3165 3166 3167 3168 3169 3170 3171 3172 3173 3174 3175 3176 3177 3178 3179 3180 3181 3182 3183 3184 3185 3186 3187 3188 3189 3190 3191 3192
			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);

3193 3194 3195 3196 3197 3198 3199 3200 3201 3202 3203 3204
	/* 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);

3205 3206 3207
	/* Mark state as coming so strong_try_module_get() ignores us,
	 * but kallsyms etc. can see us. */
	mod->state = MODULE_STATE_COMING;
3208 3209 3210 3211 3212
	mutex_unlock(&module_mutex);

	blocking_notifier_call_chain(&module_notify_list,
				     MODULE_STATE_COMING, mod);
	return 0;
3213 3214 3215 3216 3217 3218

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

3219 3220
static int unknown_module_param_cb(char *param, char *val, const char *modname)
{
3221
	/* Check for magic 'dyndbg' arg */
3222
	int ret = ddebug_dyndbg_module_param_cb(param, val, modname);
A
Andrew Morton 已提交
3223 3224
	if (ret != 0)
		pr_warn("%s: unknown parameter '%s' ignored\n", modname, param);
3225 3226 3227
	return 0;
}

R
Rusty Russell 已提交
3228 3229
/* Allocate and load the module: note that size of section 0 is always
   zero, and we rely on this for optional sections. */
3230 3231
static int load_module(struct load_info *info, const char __user *uargs,
		       int flags)
R
Rusty Russell 已提交
3232
{
3233
	struct module *mod;
R
Rusty Russell 已提交
3234
	long err;
3235
	char *after_dashes;
R
Rusty Russell 已提交
3236

3237 3238 3239
	err = module_sig_check(info);
	if (err)
		goto free_copy;
R
Rusty Russell 已提交
3240

3241
	err = elf_header_check(info);
R
Rusty Russell 已提交
3242
	if (err)
3243
		goto free_copy;
R
Rusty Russell 已提交
3244 3245

	/* Figure out module layout, and allocate all the memory. */
3246
	mod = layout_and_allocate(info, flags);
3247 3248
	if (IS_ERR(mod)) {
		err = PTR_ERR(mod);
R
Rusty Russell 已提交
3249
		goto free_copy;
L
Linus Torvalds 已提交
3250 3251
	}

3252 3253 3254
	/* Reserve our place in the list. */
	err = add_unformed_module(mod);
	if (err)
3255 3256
		goto free_module;

R
Rusty Russell 已提交
3257
#ifdef CONFIG_MODULE_SIG
3258
	mod->sig_ok = info->sig_ok;
3259
	if (!mod->sig_ok) {
A
Andrew Morton 已提交
3260
		pr_notice_once("%s: module verification failed: signature "
3261
			       "and/or required key missing - tainting "
A
Andrew Morton 已提交
3262
			       "kernel\n", mod->name);
3263
		add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK);
3264
	}
R
Rusty Russell 已提交
3265 3266
#endif

3267
	/* To avoid stressing percpu allocator, do this once we're unique. */
R
Rusty Russell 已提交
3268
	err = percpu_modalloc(mod, info);
3269 3270 3271
	if (err)
		goto unlink_mod;

3272
	/* Now module is in final location, initialize linked lists, etc. */
3273 3274
	err = module_unload_init(mod);
	if (err)
3275
		goto unlink_mod;
L
Linus Torvalds 已提交
3276

3277 3278
	/* Now we've got everything in the final locations, we can
	 * find optional sections. */
3279 3280 3281
	err = find_module_sections(mod, info);
	if (err)
		goto free_unload;
3282

3283
	err = check_module_license_and_versions(mod);
3284 3285
	if (err)
		goto free_unload;
3286

3287
	/* Set up MODINFO_ATTR fields */
3288
	setup_modinfo(mod, info);
3289

L
Linus Torvalds 已提交
3290
	/* Fix up syms, so that st_value is a pointer to location. */
3291
	err = simplify_symbols(mod, info);
L
Linus Torvalds 已提交
3292
	if (err < 0)
R
Rusty Russell 已提交
3293
		goto free_modinfo;
L
Linus Torvalds 已提交
3294

3295
	err = apply_relocations(mod, info);
3296
	if (err < 0)
R
Rusty Russell 已提交
3297
		goto free_modinfo;
L
Linus Torvalds 已提交
3298

3299
	err = post_relocation(mod, info);
L
Linus Torvalds 已提交
3300
	if (err < 0)
R
Rusty Russell 已提交
3301
		goto free_modinfo;
L
Linus Torvalds 已提交
3302

3303
	flush_module_icache(mod);
3304

3305 3306 3307 3308 3309 3310
	/* 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;
	}
R
Rusty Russell 已提交
3311

3312
	dynamic_debug_setup(info->debug, info->num_debug);
3313

3314 3315 3316
	/* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
	ftrace_module_init(mod);

3317 3318 3319
	/* Finally it's fully formed, ready to start executing. */
	err = complete_formation(mod, info);
	if (err)
3320
		goto ddebug_cleanup;
3321

3322
	/* Module is ready to execute: parsing args may do that. */
3323 3324 3325 3326
	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);
3327
		goto bug_cleanup;
3328 3329 3330 3331
	} else if (after_dashes) {
		pr_warn("%s: parameters '%s' after `--' ignored\n",
		       mod->name, after_dashes);
	}
L
Linus Torvalds 已提交
3332

3333
	/* Link in to syfs. */
3334
	err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
L
Linus Torvalds 已提交
3335
	if (err < 0)
3336
		goto bug_cleanup;
3337

3338
	/* Get rid of temporary copy. */
3339
	free_copy(info);
L
Linus Torvalds 已提交
3340 3341

	/* Done! */
3342
	trace_module_load(mod);
3343 3344

	return do_init_module(mod);
L
Linus Torvalds 已提交
3345

3346 3347
 bug_cleanup:
	/* module_bug_cleanup needs module_mutex protection */
3348
	mutex_lock(&module_mutex);
3349
	module_bug_cleanup(mod);
3350
	mutex_unlock(&module_mutex);
3351 3352 3353 3354 3355

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

3356
 ddebug_cleanup:
3357
	dynamic_debug_remove(info->debug);
3358
	synchronize_sched();
3359 3360
	kfree(mod->args);
 free_arch_cleanup:
L
Linus Torvalds 已提交
3361
	module_arch_cleanup(mod);
R
Rusty Russell 已提交
3362
 free_modinfo:
3363
	free_modinfo(mod);
3364
 free_unload:
L
Linus Torvalds 已提交
3365
	module_unload_free(mod);
3366 3367 3368 3369 3370
 unlink_mod:
	mutex_lock(&module_mutex);
	/* Unlink carefully: kallsyms could be walking list. */
	list_del_rcu(&mod->list);
	wake_up_all(&module_wq);
3371 3372
	/* Wait for RCU synchronizing before releasing mod->list. */
	synchronize_rcu();
3373
	mutex_unlock(&module_mutex);
R
Rusty Russell 已提交
3374
 free_module:
3375 3376 3377
	/* Free lock-classes; relies on the preceding sync_rcu() */
	lockdep_free_key_range(mod->module_core, mod->core_size);

3378
	module_deallocate(mod, info);
R
Rusty Russell 已提交
3379
 free_copy:
3380 3381
	free_copy(info);
	return err;
3382 3383
}

3384 3385
SYSCALL_DEFINE3(init_module, void __user *, umod,
		unsigned long, len, const char __user *, uargs)
L
Linus Torvalds 已提交
3386
{
3387 3388
	int err;
	struct load_info info = { };
L
Linus Torvalds 已提交
3389

3390 3391 3392
	err = may_init_module();
	if (err)
		return err;
L
Linus Torvalds 已提交
3393

3394 3395
	pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
	       umod, len, uargs);
L
Linus Torvalds 已提交
3396

3397 3398 3399
	err = copy_module_from_user(umod, len, &info);
	if (err)
		return err;
L
Linus Torvalds 已提交
3400

3401
	return load_module(&info, uargs, 0);
3402
}
3403

3404
SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
3405 3406 3407
{
	int err;
	struct load_info info = { };
3408

3409 3410 3411
	err = may_init_module();
	if (err)
		return err;
L
Linus Torvalds 已提交
3412

3413
	pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags);
3414

3415 3416 3417
	if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS
		      |MODULE_INIT_IGNORE_VERMAGIC))
		return -EINVAL;
3418

3419 3420 3421
	err = copy_module_from_fd(fd, &info);
	if (err)
		return err;
L
Linus Torvalds 已提交
3422

3423
	return load_module(&info, uargs, flags);
L
Linus Torvalds 已提交
3424 3425 3426 3427 3428 3429 3430 3431 3432 3433 3434 3435 3436 3437
}

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 $d.
 */
static inline int is_arm_mapping_symbol(const char *str)
{
3438 3439
	if (str[0] == '.' && str[1] == 'L')
		return true;
K
Kyle McMartin 已提交
3440
	return str[0] == '$' && strchr("axtd", str[1])
L
Linus Torvalds 已提交
3441 3442 3443 3444 3445 3446 3447 3448 3449 3450 3451 3452
	       && (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 */
3453
	if (within_module_init(addr, mod))
L
Linus Torvalds 已提交
3454
		nextval = (unsigned long)mod->module_init+mod->init_text_size;
D
Daniel Walker 已提交
3455
	else
L
Linus Torvalds 已提交
3456 3457
		nextval = (unsigned long)mod->module_core+mod->core_text_size;

L
Lucas De Marchi 已提交
3458
	/* Scan for closest preceding symbol, and next symbol. (ELF
D
Daniel Walker 已提交
3459
	   starts real symbols at 1). */
L
Linus Torvalds 已提交
3460 3461 3462 3463 3464 3465 3466 3467 3468 3469 3470 3471 3472 3473 3474 3475 3476 3477 3478 3479 3480
	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;

A
Alexey Dobriyan 已提交
3481 3482 3483 3484
	if (size)
		*size = nextval - mod->symtab[best].st_value;
	if (offset)
		*offset = addr - mod->symtab[best].st_value;
L
Linus Torvalds 已提交
3485 3486 3487
	return mod->strtab + mod->symtab[best].st_name;
}

3488 3489
/* For kallsyms to ask for address resolution.  NULL means not found.  Careful
 * not to lock to avoid deadlock on oopses, simply disable preemption. */
3490
const char *module_address_lookup(unsigned long addr,
3491 3492 3493 3494
			    unsigned long *size,
			    unsigned long *offset,
			    char **modname,
			    char *namebuf)
L
Linus Torvalds 已提交
3495 3496
{
	struct module *mod;
3497
	const char *ret = NULL;
L
Linus Torvalds 已提交
3498

3499
	preempt_disable();
3500
	list_for_each_entry_rcu(mod, &modules, list) {
3501 3502
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
3503
		if (within_module(addr, mod)) {
3504 3505
			if (modname)
				*modname = mod->name;
3506 3507
			ret = get_ksymbol(mod, addr, size, offset);
			break;
L
Linus Torvalds 已提交
3508 3509
		}
	}
3510 3511 3512 3513 3514
	/* Make a copy in here where it's safe */
	if (ret) {
		strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
		ret = namebuf;
	}
3515
	preempt_enable();
3516
	return ret;
L
Linus Torvalds 已提交
3517 3518
}

3519 3520 3521 3522
int lookup_module_symbol_name(unsigned long addr, char *symname)
{
	struct module *mod;

3523
	preempt_disable();
3524
	list_for_each_entry_rcu(mod, &modules, list) {
3525 3526
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
3527
		if (within_module(addr, mod)) {
3528 3529 3530 3531 3532
			const char *sym;

			sym = get_ksymbol(mod, addr, NULL, NULL);
			if (!sym)
				goto out;
3533
			strlcpy(symname, sym, KSYM_NAME_LEN);
3534
			preempt_enable();
3535 3536 3537 3538
			return 0;
		}
	}
out:
3539
	preempt_enable();
3540 3541 3542
	return -ERANGE;
}

3543 3544 3545 3546 3547
int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
			unsigned long *offset, char *modname, char *name)
{
	struct module *mod;

3548
	preempt_disable();
3549
	list_for_each_entry_rcu(mod, &modules, list) {
3550 3551
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
3552
		if (within_module(addr, mod)) {
3553 3554 3555 3556 3557 3558
			const char *sym;

			sym = get_ksymbol(mod, addr, size, offset);
			if (!sym)
				goto out;
			if (modname)
3559
				strlcpy(modname, mod->name, MODULE_NAME_LEN);
3560
			if (name)
3561
				strlcpy(name, sym, KSYM_NAME_LEN);
3562
			preempt_enable();
3563 3564 3565 3566
			return 0;
		}
	}
out:
3567
	preempt_enable();
3568 3569 3570
	return -ERANGE;
}

3571 3572
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
3573 3574 3575
{
	struct module *mod;

3576
	preempt_disable();
3577
	list_for_each_entry_rcu(mod, &modules, list) {
3578 3579
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
L
Linus Torvalds 已提交
3580 3581 3582
		if (symnum < mod->num_symtab) {
			*value = mod->symtab[symnum].st_value;
			*type = mod->symtab[symnum].st_info;
3583
			strlcpy(name, mod->strtab + mod->symtab[symnum].st_name,
3584 3585
				KSYM_NAME_LEN);
			strlcpy(module_name, mod->name, MODULE_NAME_LEN);
3586
			*exported = is_exported(name, *value, mod);
3587
			preempt_enable();
3588
			return 0;
L
Linus Torvalds 已提交
3589 3590 3591
		}
		symnum -= mod->num_symtab;
	}
3592
	preempt_enable();
3593
	return -ERANGE;
L
Linus Torvalds 已提交
3594 3595 3596 3597 3598 3599 3600
}

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

	for (i = 0; i < mod->num_symtab; i++)
3601 3602
		if (strcmp(name, mod->strtab+mod->symtab[i].st_name) == 0 &&
		    mod->symtab[i].st_info != 'U')
L
Linus Torvalds 已提交
3603 3604 3605 3606 3607 3608 3609 3610 3611 3612 3613 3614
			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. */
3615
	preempt_disable();
L
Linus Torvalds 已提交
3616
	if ((colon = strchr(name, ':')) != NULL) {
3617
		if ((mod = find_module_all(name, colon - name, false)) != NULL)
L
Linus Torvalds 已提交
3618 3619
			ret = mod_find_symname(mod, colon+1);
	} else {
3620 3621 3622
		list_for_each_entry_rcu(mod, &modules, list) {
			if (mod->state == MODULE_STATE_UNFORMED)
				continue;
L
Linus Torvalds 已提交
3623 3624
			if ((ret = mod_find_symname(mod, name)) != 0)
				break;
3625
		}
L
Linus Torvalds 已提交
3626
	}
3627
	preempt_enable();
L
Linus Torvalds 已提交
3628 3629
	return ret;
}
3630 3631 3632 3633 3634 3635 3636 3637 3638 3639

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) {
3640 3641
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
3642 3643 3644 3645 3646 3647 3648 3649 3650
		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
3651 3652
#endif /* CONFIG_KALLSYMS */

3653
static char *module_flags(struct module *mod, char *buf)
3654 3655 3656
{
	int bx = 0;

3657
	BUG_ON(mod->state == MODULE_STATE_UNFORMED);
3658 3659 3660
	if (mod->taints ||
	    mod->state == MODULE_STATE_GOING ||
	    mod->state == MODULE_STATE_COMING) {
3661
		buf[bx++] = '(';
3662
		bx += module_flags_taint(mod, buf + bx);
3663 3664 3665 3666 3667 3668
		/* 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++] = '+';
3669 3670 3671 3672 3673 3674 3675
		buf[bx++] = ')';
	}
	buf[bx] = '\0';

	return buf;
}

3676 3677 3678 3679 3680 3681 3682 3683 3684 3685 3686 3687 3688 3689 3690 3691 3692 3693
#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
3694 3695 3696
static int m_show(struct seq_file *m, void *p)
{
	struct module *mod = list_entry(p, struct module, list);
3697 3698
	char buf[8];

3699 3700 3701 3702
	/* We always ignore unformed modules. */
	if (mod->state == MODULE_STATE_UNFORMED)
		return 0;

3703
	seq_printf(m, "%s %u",
L
Linus Torvalds 已提交
3704 3705 3706 3707 3708
		   mod->name, mod->init_size + mod->core_size);
	print_unload_info(m, mod);

	/* Informative for users. */
	seq_printf(m, " %s",
3709 3710
		   mod->state == MODULE_STATE_GOING ? "Unloading" :
		   mod->state == MODULE_STATE_COMING ? "Loading" :
L
Linus Torvalds 已提交
3711 3712
		   "Live");
	/* Used by oprofile and other similar tools. */
3713
	seq_printf(m, " 0x%pK", mod->module_core);
L
Linus Torvalds 已提交
3714

3715 3716
	/* Taints info */
	if (mod->taints)
3717
		seq_printf(m, " %s", module_flags(mod, buf));
3718

3719
	seq_puts(m, "\n");
L
Linus Torvalds 已提交
3720 3721 3722 3723 3724 3725 3726 3727
	return 0;
}

/* Format: modulename size refcount deps address

   Where refcount is a number or -, and deps is a comma-separated list
   of depends or -.
*/
3728
static const struct seq_operations modules_op = {
L
Linus Torvalds 已提交
3729 3730 3731 3732 3733 3734
	.start	= m_start,
	.next	= m_next,
	.stop	= m_stop,
	.show	= m_show
};

3735 3736 3737 3738 3739 3740 3741 3742 3743 3744 3745 3746 3747 3748 3749 3750 3751 3752 3753 3754
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
3755 3756 3757 3758 3759 3760
/* 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;

R
Rusty Russell 已提交
3761
	preempt_disable();
3762
	list_for_each_entry_rcu(mod, &modules, list) {
3763 3764
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
L
Linus Torvalds 已提交
3765 3766
		if (mod->num_exentries == 0)
			continue;
D
Daniel Walker 已提交
3767

L
Linus Torvalds 已提交
3768 3769 3770 3771 3772 3773
		e = search_extable(mod->extable,
				   mod->extable + mod->num_exentries - 1,
				   addr);
		if (e)
			break;
	}
R
Rusty Russell 已提交
3774
	preempt_enable();
L
Linus Torvalds 已提交
3775 3776

	/* Now, if we found one, we are running inside it now, hence
D
Daniel Walker 已提交
3777
	   we cannot unload the module, hence no refcnt needed. */
L
Linus Torvalds 已提交
3778 3779 3780
	return e;
}

3781
/*
R
Rusty Russell 已提交
3782 3783 3784 3785 3786
 * 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).
3787
 */
R
Rusty Russell 已提交
3788
bool is_module_address(unsigned long addr)
3789
{
R
Rusty Russell 已提交
3790
	bool ret;
3791

R
Rusty Russell 已提交
3792
	preempt_disable();
R
Rusty Russell 已提交
3793
	ret = __module_address(addr) != NULL;
R
Rusty Russell 已提交
3794
	preempt_enable();
3795

R
Rusty Russell 已提交
3796
	return ret;
3797 3798
}

R
Rusty Russell 已提交
3799 3800 3801 3802 3803 3804 3805
/*
 * __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.
 */
3806
struct module *__module_address(unsigned long addr)
L
Linus Torvalds 已提交
3807 3808 3809
{
	struct module *mod;

3810 3811 3812
	if (addr < module_addr_min || addr > module_addr_max)
		return NULL;

3813 3814 3815
	list_for_each_entry_rcu(mod, &modules, list) {
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
3816
		if (within_module(addr, mod))
L
Linus Torvalds 已提交
3817
			return mod;
3818
	}
L
Linus Torvalds 已提交
3819 3820
	return NULL;
}
3821
EXPORT_SYMBOL_GPL(__module_address);
L
Linus Torvalds 已提交
3822

R
Rusty Russell 已提交
3823 3824 3825 3826 3827 3828 3829 3830 3831 3832 3833 3834 3835 3836 3837 3838 3839 3840 3841 3842 3843 3844 3845 3846 3847 3848 3849 3850 3851 3852 3853 3854 3855 3856 3857 3858 3859
/*
 * 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;
}
3860
EXPORT_SYMBOL_GPL(__module_text_address);
R
Rusty Russell 已提交
3861

L
Linus Torvalds 已提交
3862 3863 3864 3865
/* Don't grab lock, we're oopsing. */
void print_modules(void)
{
	struct module *mod;
3866
	char buf[8];
L
Linus Torvalds 已提交
3867

3868
	printk(KERN_DEFAULT "Modules linked in:");
3869 3870
	/* Most callers should already have preempt disabled, but make sure */
	preempt_disable();
3871 3872 3873
	list_for_each_entry_rcu(mod, &modules, list) {
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
J
Jiri Slaby 已提交
3874
		pr_cont(" %s%s", mod->name, module_flags(mod, buf));
3875
	}
3876
	preempt_enable();
3877
	if (last_unloaded_module[0])
J
Jiri Slaby 已提交
3878 3879
		pr_cont(" [last unloaded: %s]", last_unloaded_module);
	pr_cont("\n");
L
Linus Torvalds 已提交
3880 3881 3882
}

#ifdef CONFIG_MODVERSIONS
3883 3884 3885 3886 3887 3888
/* 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,
3889
		   struct tracepoint * const *tp)
3890 3891 3892
{
}
EXPORT_SYMBOL(module_layout);
L
Linus Torvalds 已提交
3893
#endif