module.c 82.2 KB
Newer Older
1
/*
L
Linus Torvalds 已提交
2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
   Copyright (C) 2002 Richard Henderson
   Copyright (C) 2001 Rusty Russell, 2002 Rusty Russell IBM.

    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
*/
#include <linux/module.h>
#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/fs.h>
R
Roland McGrath 已提交
25
#include <linux/sysfs.h>
26
#include <linux/kernel.h>
L
Linus Torvalds 已提交
27 28 29
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/elf.h>
30
#include <linux/proc_fs.h>
L
Linus Torvalds 已提交
31 32 33 34
#include <linux/seq_file.h>
#include <linux/syscalls.h>
#include <linux/fcntl.h>
#include <linux/rcupdate.h>
35
#include <linux/capability.h>
L
Linus Torvalds 已提交
36 37 38 39 40 41
#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
42
#include <linux/sched.h>
L
Linus Torvalds 已提交
43 44
#include <linux/stop_machine.h>
#include <linux/device.h>
45
#include <linux/string.h>
A
Arjan van de Ven 已提交
46
#include <linux/mutex.h>
47
#include <linux/rculist.h>
L
Linus Torvalds 已提交
48 49
#include <asm/uaccess.h>
#include <asm/cacheflush.h>
50
#include <asm/mmu_context.h>
51
#include <linux/license.h>
52
#include <asm/sections.h>
M
Mathieu Desnoyers 已提交
53
#include <linux/tracepoint.h>
54
#include <linux/ftrace.h>
55
#include <linux/async.h>
56
#include <linux/percpu.h>
C
Catalin Marinas 已提交
57
#include <linux/kmemleak.h>
L
Linus Torvalds 已提交
58

59 60 61
#define CREATE_TRACE_POINTS
#include <trace/events/module.h>

L
Linus Torvalds 已提交
62 63 64 65 66 67 68 69 70 71 72 73 74
#if 0
#define DEBUGP printk
#else
#define DEBUGP(fmt , a...)
#endif

#ifndef ARCH_SHF_SMALL
#define ARCH_SHF_SMALL 0
#endif

/* If this is set, the section belongs in the init part of the module */
#define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))

75 76 77 78 79
/*
 * Mutex protects:
 * 1) List of modules (also safely readable with preempt_disable),
 * 2) module_use links,
 * 3) module_addr_min/module_addr_max.
80
 * (delete uses stop_machine/add uses RCU list operations). */
81 82
DEFINE_MUTEX(module_mutex);
EXPORT_SYMBOL_GPL(module_mutex);
L
Linus Torvalds 已提交
83
static LIST_HEAD(modules);
84 85 86 87
#ifdef CONFIG_KGDB_KDB
struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
#endif /* CONFIG_KGDB_KDB */

L
Linus Torvalds 已提交
88

89 90 91
/* Block module loading/unloading? */
int modules_disabled = 0;

92 93 94
/* Waiting for a module to finish initializing? */
static DECLARE_WAIT_QUEUE_HEAD(module_wq);

95
static BLOCKING_NOTIFIER_HEAD(module_notify_list);
L
Linus Torvalds 已提交
96

97 98
/* Bounds of module allocation, for speeding __module_address.
 * Protected by module_mutex. */
99 100
static unsigned long module_addr_min = -1UL, module_addr_max = 0;

L
Linus Torvalds 已提交
101 102
int register_module_notifier(struct notifier_block * nb)
{
103
	return blocking_notifier_chain_register(&module_notify_list, nb);
L
Linus Torvalds 已提交
104 105 106 107 108
}
EXPORT_SYMBOL(register_module_notifier);

int unregister_module_notifier(struct notifier_block * nb)
{
109
	return blocking_notifier_chain_unregister(&module_notify_list, nb);
L
Linus Torvalds 已提交
110 111 112
}
EXPORT_SYMBOL(unregister_module_notifier);

113 114
/* We require a truly strong try_module_get(): 0 means failure due to
   ongoing or failed initialization etc. */
L
Linus Torvalds 已提交
115 116 117
static inline int strong_try_module_get(struct module *mod)
{
	if (mod && mod->state == MODULE_STATE_COMING)
118 119
		return -EBUSY;
	if (try_module_get(mod))
L
Linus Torvalds 已提交
120
		return 0;
121 122
	else
		return -ENOENT;
L
Linus Torvalds 已提交
123 124
}

125 126 127
static inline void add_taint_module(struct module *mod, unsigned flag)
{
	add_taint(flag);
A
Andi Kleen 已提交
128
	mod->taints |= (1U << flag);
129 130
}

131 132 133
/*
 * 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
134 135 136 137 138 139 140
 */
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
141

L
Linus Torvalds 已提交
142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157
/* Find a module section: 0 means not found. */
static unsigned int find_sec(Elf_Ehdr *hdr,
			     Elf_Shdr *sechdrs,
			     const char *secstrings,
			     const char *name)
{
	unsigned int i;

	for (i = 1; i < hdr->e_shnum; i++)
		/* Alloc bit cleared means "ignore it." */
		if ((sechdrs[i].sh_flags & SHF_ALLOC)
		    && strcmp(secstrings+sechdrs[i].sh_name, name) == 0)
			return i;
	return 0;
}

R
Rusty Russell 已提交
158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180
/* Find a module section, or NULL. */
static void *section_addr(Elf_Ehdr *hdr, Elf_Shdr *shdrs,
			  const char *secstrings, const char *name)
{
	/* Section 0 has sh_addr 0. */
	return (void *)shdrs[find_sec(hdr, shdrs, secstrings, name)].sh_addr;
}

/* Find a module section, or NULL.  Fill in number of "objects" in section. */
static void *section_objs(Elf_Ehdr *hdr,
			  Elf_Shdr *sechdrs,
			  const char *secstrings,
			  const char *name,
			  size_t object_size,
			  unsigned int *num)
{
	unsigned int sec = find_sec(hdr, sechdrs, secstrings, name);

	/* Section 0 has sh_addr 0 and sh_size 0. */
	*num = sechdrs[sec].sh_size / object_size;
	return (void *)sechdrs[sec].sh_addr;
}

L
Linus Torvalds 已提交
181 182 183 184 185
/* 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[];
186 187
extern const struct kernel_symbol __start___ksymtab_gpl_future[];
extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
L
Linus Torvalds 已提交
188 189
extern const unsigned long __start___kcrctab[];
extern const unsigned long __start___kcrctab_gpl[];
190
extern const unsigned long __start___kcrctab_gpl_future[];
191 192 193 194 195
#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[];
196 197
extern const unsigned long __start___kcrctab_unused[];
extern const unsigned long __start___kcrctab_unused_gpl[];
198
#endif
L
Linus Torvalds 已提交
199 200 201 202

#ifndef CONFIG_MODVERSIONS
#define symversion(base, idx) NULL
#else
A
Andrew Morton 已提交
203
#define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
L
Linus Torvalds 已提交
204 205
#endif

206 207 208 209 210 211 212
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,
					      unsigned int symnum, void *data),
				   void *data)
213
{
214
	unsigned int i, j;
215

216 217 218 219
	for (j = 0; j < arrsize; j++) {
		for (i = 0; i < arr[j].stop - arr[j].start; i++)
			if (fn(&arr[j], owner, i, data))
				return true;
220
	}
221 222

	return false;
223 224
}

225
/* Returns true as soon as fn returns true, otherwise false. */
226 227
bool each_symbol(bool (*fn)(const struct symsearch *arr, struct module *owner,
			    unsigned int symnum, void *data), void *data)
228 229 230 231
{
	struct module *mod;
	const struct symsearch arr[] = {
		{ __start___ksymtab, __stop___ksymtab, __start___kcrctab,
232
		  NOT_GPL_ONLY, false },
233
		{ __start___ksymtab_gpl, __stop___ksymtab_gpl,
234 235
		  __start___kcrctab_gpl,
		  GPL_ONLY, false },
236
		{ __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future,
237 238
		  __start___kcrctab_gpl_future,
		  WILL_BE_GPL_ONLY, false },
239
#ifdef CONFIG_UNUSED_SYMBOLS
240
		{ __start___ksymtab_unused, __stop___ksymtab_unused,
241 242
		  __start___kcrctab_unused,
		  NOT_GPL_ONLY, true },
243
		{ __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl,
244 245
		  __start___kcrctab_unused_gpl,
		  GPL_ONLY, true },
246
#endif
247
	};
248

249 250
	if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data))
		return true;
251

252
	list_for_each_entry_rcu(mod, &modules, list) {
253 254
		struct symsearch arr[] = {
			{ mod->syms, mod->syms + mod->num_syms, mod->crcs,
255
			  NOT_GPL_ONLY, false },
256
			{ mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
257 258
			  mod->gpl_crcs,
			  GPL_ONLY, false },
259 260
			{ mod->gpl_future_syms,
			  mod->gpl_future_syms + mod->num_gpl_future_syms,
261 262
			  mod->gpl_future_crcs,
			  WILL_BE_GPL_ONLY, false },
263
#ifdef CONFIG_UNUSED_SYMBOLS
264 265
			{ mod->unused_syms,
			  mod->unused_syms + mod->num_unused_syms,
266 267
			  mod->unused_crcs,
			  NOT_GPL_ONLY, true },
268 269
			{ mod->unused_gpl_syms,
			  mod->unused_gpl_syms + mod->num_unused_gpl_syms,
270 271
			  mod->unused_gpl_crcs,
			  GPL_ONLY, true },
272
#endif
273 274
		};

275 276 277 278 279
		if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data))
			return true;
	}
	return false;
}
280
EXPORT_SYMBOL_GPL(each_symbol);
281 282 283 284 285 286 287 288 289 290

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

	/* Output */
	struct module *owner;
	const unsigned long *crc;
291
	const struct kernel_symbol *sym;
292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312
};

static bool find_symbol_in_section(const struct symsearch *syms,
				   struct module *owner,
				   unsigned int symnum, void *data)
{
	struct find_symbol_arg *fsa = data;

	if (strcmp(syms->start[symnum].name, fsa->name) != 0)
		return false;

	if (!fsa->gplok) {
		if (syms->licence == GPL_ONLY)
			return false;
		if (syms->licence == WILL_BE_GPL_ONLY && fsa->warn) {
			printk(KERN_WARNING "Symbol %s is being used "
			       "by a non-GPL module, which will not "
			       "be allowed in the future\n", fsa->name);
			printk(KERN_WARNING "Please see the file "
			       "Documentation/feature-removal-schedule.txt "
			       "in the kernel source tree for more details.\n");
313
		}
L
Linus Torvalds 已提交
314
	}
315

316
#ifdef CONFIG_UNUSED_SYMBOLS
317 318 319 320 321 322 323 324 325 326 327
	if (syms->unused && fsa->warn) {
		printk(KERN_WARNING "Symbol %s is marked as UNUSED, "
		       "however this module is using it.\n", fsa->name);
		printk(KERN_WARNING
		       "This symbol will go away in the future.\n");
		printk(KERN_WARNING
		       "Please evalute if this is the right api to use and if "
		       "it really is, submit a report the linux kernel "
		       "mailinglist together with submitting your code for "
		       "inclusion.\n");
	}
328
#endif
329 330 331

	fsa->owner = owner;
	fsa->crc = symversion(syms->crcs, symnum);
332
	fsa->sym = &syms->start[symnum];
333 334 335
	return true;
}

336
/* Find a symbol and return it, along with, (optional) crc and
337
 * (optional) module which owns it.  Needs preempt disabled or module_mutex. */
338 339 340 341 342
const struct kernel_symbol *find_symbol(const char *name,
					struct module **owner,
					const unsigned long **crc,
					bool gplok,
					bool warn)
343 344 345 346 347 348 349 350 351 352 353 354
{
	struct find_symbol_arg fsa;

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

	if (each_symbol(find_symbol_in_section, &fsa)) {
		if (owner)
			*owner = fsa.owner;
		if (crc)
			*crc = fsa.crc;
355
		return fsa.sym;
356 357
	}

L
Linus Torvalds 已提交
358
	DEBUGP("Failed to find symbol %s\n", name);
359
	return NULL;
L
Linus Torvalds 已提交
360
}
361
EXPORT_SYMBOL_GPL(find_symbol);
L
Linus Torvalds 已提交
362 363

/* Search for module by name: must hold module_mutex. */
364
struct module *find_module(const char *name)
L
Linus Torvalds 已提交
365 366 367 368 369 370 371 372 373
{
	struct module *mod;

	list_for_each_entry(mod, &modules, list) {
		if (strcmp(mod->name, name) == 0)
			return mod;
	}
	return NULL;
}
374
EXPORT_SYMBOL_GPL(find_module);
L
Linus Torvalds 已提交
375 376

#ifdef CONFIG_SMP
377

378
static inline void __percpu *mod_percpu(struct module *mod)
379
{
380 381
	return mod->percpu;
}
382

383 384 385
static int percpu_modalloc(struct module *mod,
			   unsigned long size, unsigned long align)
{
386 387
	if (align > PAGE_SIZE) {
		printk(KERN_WARNING "%s: per-cpu alignment %li > %li\n",
388
		       mod->name, align, PAGE_SIZE);
389 390 391
		align = PAGE_SIZE;
	}

392 393
	mod->percpu = __alloc_reserved_percpu(size, align);
	if (!mod->percpu) {
394 395
		printk(KERN_WARNING
		       "Could not allocate %lu bytes percpu data\n", size);
396 397 398 399
		return -ENOMEM;
	}
	mod->percpu_size = size;
	return 0;
400 401
}

402
static void percpu_modfree(struct module *mod)
403
{
404
	free_percpu(mod->percpu);
405 406
}

407 408 409 410
static unsigned int find_pcpusec(Elf_Ehdr *hdr,
				 Elf_Shdr *sechdrs,
				 const char *secstrings)
{
411
	return find_sec(hdr, sechdrs, secstrings, ".data..percpu");
412 413
}

414 415
static void percpu_modcopy(struct module *mod,
			   const void *from, unsigned long size)
416 417 418 419
{
	int cpu;

	for_each_possible_cpu(cpu)
420
		memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
421 422
}

423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454
/**
 * 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) {
		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;
455 456
}

L
Linus Torvalds 已提交
457
#else /* ... !CONFIG_SMP */
458

459
static inline void __percpu *mod_percpu(struct module *mod)
L
Linus Torvalds 已提交
460 461 462
{
	return NULL;
}
463 464 465 466 467 468
static inline int percpu_modalloc(struct module *mod,
				  unsigned long size, unsigned long align)
{
	return -ENOMEM;
}
static inline void percpu_modfree(struct module *mod)
L
Linus Torvalds 已提交
469 470 471 472 473 474 475 476
{
}
static inline unsigned int find_pcpusec(Elf_Ehdr *hdr,
					Elf_Shdr *sechdrs,
					const char *secstrings)
{
	return 0;
}
477 478
static inline void percpu_modcopy(struct module *mod,
				  const void *from, unsigned long size)
L
Linus Torvalds 已提交
479 480 481 482
{
	/* pcpusec should be 0, and size of that section should be 0. */
	BUG_ON(size != 0);
}
483 484 485 486
bool is_module_percpu_address(unsigned long addr)
{
	return false;
}
487

L
Linus Torvalds 已提交
488 489
#endif /* CONFIG_SMP */

490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505
#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,   \
	                struct module *mod, char *buffer)             \
{                                                                     \
	return sprintf(buffer, "%s\n", mod->field);                   \
}                                                                     \
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
506 507
	kfree(mod->field);                                            \
	mod->field = NULL;                                            \
508 509
}                                                                     \
static struct module_attribute modinfo_##field = {                    \
510
	.attr = { .name = __stringify(field), .mode = 0444 },         \
511 512 513 514 515 516 517 518 519
	.show = show_modinfo_##field,                                 \
	.setup = setup_modinfo_##field,                               \
	.test = modinfo_##field##_exists,                             \
	.free = free_modinfo_##field,                                 \
};

MODINFO_ATTR(version);
MODINFO_ATTR(srcversion);

520 521
static char last_unloaded_module[MODULE_NAME_LEN+1];

522
#ifdef CONFIG_MODULE_UNLOAD
523 524 525

EXPORT_TRACEPOINT_SYMBOL(module_get);

L
Linus Torvalds 已提交
526
/* Init the unload section of the module. */
527
static int module_unload_init(struct module *mod)
L
Linus Torvalds 已提交
528
{
529 530 531 532
	mod->refptr = alloc_percpu(struct module_ref);
	if (!mod->refptr)
		return -ENOMEM;

533 534
	INIT_LIST_HEAD(&mod->source_list);
	INIT_LIST_HEAD(&mod->target_list);
535

L
Linus Torvalds 已提交
536
	/* Hold reference count during initialization. */
537
	__this_cpu_write(mod->refptr->incs, 1);
L
Linus Torvalds 已提交
538 539
	/* Backwards compatibility macros put refcount during init. */
	mod->waiter = current;
540 541

	return 0;
L
Linus Torvalds 已提交
542 543 544 545 546 547 548
}

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

549 550
	list_for_each_entry(use, &b->source_list, source_list) {
		if (use->source == a) {
L
Linus Torvalds 已提交
551 552 553 554 555 556 557 558
			DEBUGP("%s uses %s!\n", a->name, b->name);
			return 1;
		}
	}
	DEBUGP("%s does not use %s!\n", a->name, b->name);
	return 0;
}

559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583
/*
 * 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;

	DEBUGP("Allocating new usage for %s.\n", a->name);
	use = kmalloc(sizeof(*use), GFP_ATOMIC);
	if (!use) {
		printk(KERN_WARNING "%s: out of memory loading\n", a->name);
		return -ENOMEM;
	}

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

584
/* Module a uses b: caller needs module_mutex() */
585
int ref_module(struct module *a, struct module *b)
L
Linus Torvalds 已提交
586
{
587
	int err;
K
Kay Sievers 已提交
588

589
	if (b == NULL || already_uses(a, b))
590 591
		return 0;

592 593
	/* If module isn't available, we fail. */
	err = strong_try_module_get(b);
594
	if (err)
595
		return err;
L
Linus Torvalds 已提交
596

597 598
	err = add_module_usage(a, b);
	if (err) {
L
Linus Torvalds 已提交
599
		module_put(b);
600
		return err;
L
Linus Torvalds 已提交
601
	}
602
	return 0;
L
Linus Torvalds 已提交
603
}
604
EXPORT_SYMBOL_GPL(ref_module);
L
Linus Torvalds 已提交
605 606 607 608

/* Clear the unload stuff of the module. */
static void module_unload_free(struct module *mod)
{
609
	struct module_use *use, *tmp;
L
Linus Torvalds 已提交
610

611
	mutex_lock(&module_mutex);
612 613 614 615 616 617 618
	list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
		struct module *i = use->target;
		DEBUGP("%s unusing %s\n", mod->name, i->name);
		module_put(i);
		list_del(&use->source_list);
		list_del(&use->target_list);
		kfree(use);
L
Linus Torvalds 已提交
619
	}
620
	mutex_unlock(&module_mutex);
621 622

	free_percpu(mod->refptr);
L
Linus Torvalds 已提交
623 624 625
}

#ifdef CONFIG_MODULE_FORCE_UNLOAD
626
static inline int try_force_unload(unsigned int flags)
L
Linus Torvalds 已提交
627 628 629
{
	int ret = (flags & O_TRUNC);
	if (ret)
630
		add_taint(TAINT_FORCED_RMMOD);
L
Linus Torvalds 已提交
631 632 633
	return ret;
}
#else
634
static inline int try_force_unload(unsigned int flags)
L
Linus Torvalds 已提交
635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651
{
	return 0;
}
#endif /* CONFIG_MODULE_FORCE_UNLOAD */

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

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

652 653
	/* If it's not unused, quit unless we're forcing. */
	if (module_refcount(sref->mod) != 0) {
654
		if (!(*sref->forced = try_force_unload(sref->flags)))
L
Linus Torvalds 已提交
655 656 657 658 659 660 661 662 663 664
			return -EWOULDBLOCK;
	}

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

static int try_stop_module(struct module *mod, int flags, int *forced)
{
665 666
	if (flags & O_NONBLOCK) {
		struct stopref sref = { mod, flags, forced };
L
Linus Torvalds 已提交
667

668
		return stop_machine(__try_stop_module, &sref, NULL);
669 670 671 672 673 674
	} else {
		/* We don't need to stop the machine for this. */
		mod->state = MODULE_STATE_GOING;
		synchronize_sched();
		return 0;
	}
L
Linus Torvalds 已提交
675 676 677 678
}

unsigned int module_refcount(struct module *mod)
{
679
	unsigned int incs = 0, decs = 0;
680
	int cpu;
L
Linus Torvalds 已提交
681

682
	for_each_possible_cpu(cpu)
683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700
		decs += per_cpu_ptr(mod->refptr, cpu)->decs;
	/*
	 * ensure the incs are added up after the decs.
	 * module_put ensures incs are visible before decs with smp_wmb.
	 *
	 * This 2-count scheme avoids the situation where the refcount
	 * for CPU0 is read, then CPU0 increments the module refcount,
	 * then CPU1 drops that refcount, then the refcount for CPU1 is
	 * read. We would record a decrement but not its corresponding
	 * increment so we would see a low count (disaster).
	 *
	 * Rare situation? But module_refcount can be preempted, and we
	 * might be tallying up 4096+ CPUs. So it is not impossible.
	 */
	smp_rmb();
	for_each_possible_cpu(cpu)
		incs += per_cpu_ptr(mod->refptr, cpu)->incs;
	return incs - decs;
L
Linus Torvalds 已提交
701 702 703 704 705 706 707 708
}
EXPORT_SYMBOL(module_refcount);

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

static void wait_for_zero_refcount(struct module *mod)
{
709
	/* Since we might sleep for some time, release the mutex first */
710
	mutex_unlock(&module_mutex);
L
Linus Torvalds 已提交
711 712 713 714 715 716 717 718
	for (;;) {
		DEBUGP("Looking at refcount...\n");
		set_current_state(TASK_UNINTERRUPTIBLE);
		if (module_refcount(mod) == 0)
			break;
		schedule();
	}
	current->state = TASK_RUNNING;
719
	mutex_lock(&module_mutex);
L
Linus Torvalds 已提交
720 721
}

722 723
SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
		unsigned int, flags)
L
Linus Torvalds 已提交
724 725
{
	struct module *mod;
726
	char name[MODULE_NAME_LEN];
L
Linus Torvalds 已提交
727 728
	int ret, forced = 0;

729
	if (!capable(CAP_SYS_MODULE) || modules_disabled)
730 731 732 733 734 735
		return -EPERM;

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

736 737
	if (mutex_lock_interruptible(&module_mutex) != 0)
		return -EINTR;
L
Linus Torvalds 已提交
738 739 740 741 742 743 744

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

745
	if (!list_empty(&mod->source_list)) {
L
Linus Torvalds 已提交
746 747 748 749 750 751 752 753 754 755 756 757 758 759 760
		/* Other modules depend on us: get rid of them first. */
		ret = -EWOULDBLOCK;
		goto out;
	}

	/* Doing init or already dying? */
	if (mod->state != MODULE_STATE_LIVE) {
		/* FIXME: if (force), slam module count and wake up
                   waiter --RR */
		DEBUGP("%s already dying\n", mod->name);
		ret = -EBUSY;
		goto out;
	}

	/* If it has an init func, it must have an exit func to unload */
R
Rusty Russell 已提交
761
	if (mod->init && !mod->exit) {
762
		forced = try_force_unload(flags);
L
Linus Torvalds 已提交
763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781
		if (!forced) {
			/* This module can't be removed */
			ret = -EBUSY;
			goto out;
		}
	}

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

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

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

782
	mutex_unlock(&module_mutex);
L
Linus Torvalds 已提交
783
	/* Final destruction now noone is using it. */
784
	if (mod->exit != NULL)
L
Linus Torvalds 已提交
785
		mod->exit();
786 787
	blocking_notifier_call_chain(&module_notify_list,
				     MODULE_STATE_GOING, mod);
788
	async_synchronize_full();
789

790
	/* Store the name of the last unloaded module for diagnostic purposes */
791
	strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
L
Linus Torvalds 已提交
792

793 794 795
	free_module(mod);
	return 0;
out:
796
	mutex_unlock(&module_mutex);
L
Linus Torvalds 已提交
797 798 799
	return ret;
}

800
static inline void print_unload_info(struct seq_file *m, struct module *mod)
L
Linus Torvalds 已提交
801 802 803 804 805 806 807 808
{
	struct module_use *use;
	int printed_something = 0;

	seq_printf(m, " %u ", module_refcount(mod));

	/* Always include a trailing , so userspace can differentiate
           between this and the old multi-field proc format. */
809
	list_for_each_entry(use, &mod->source_list, source_list) {
L
Linus Torvalds 已提交
810
		printed_something = 1;
811
		seq_printf(m, "%s,", use->source->name);
L
Linus Torvalds 已提交
812 813 814 815 816 817 818 819 820 821 822 823 824 825 826
	}

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

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

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

R
Rusty Russell 已提交
827
	preempt_disable();
828
	if (!find_symbol(symbol, &owner, NULL, true, false))
L
Linus Torvalds 已提交
829 830
		BUG();
	module_put(owner);
R
Rusty Russell 已提交
831
	preempt_enable();
L
Linus Torvalds 已提交
832 833 834
}
EXPORT_SYMBOL(__symbol_put);

835
/* Note this assumes addr is a function, which it currently always is. */
L
Linus Torvalds 已提交
836 837
void symbol_put_addr(void *addr)
{
838
	struct module *modaddr;
839
	unsigned long a = (unsigned long)dereference_function_descriptor(addr);
L
Linus Torvalds 已提交
840

841
	if (core_kernel_text(a))
842
		return;
L
Linus Torvalds 已提交
843

844 845
	/* module_text_address is safe here: we're supposed to have reference
	 * to module from symbol_get, so it can't go away. */
846
	modaddr = __module_text_address(a);
847
	BUG_ON(!modaddr);
848
	module_put(modaddr);
L
Linus Torvalds 已提交
849 850 851 852 853 854
}
EXPORT_SYMBOL_GPL(symbol_put_addr);

static ssize_t show_refcnt(struct module_attribute *mattr,
			   struct module *mod, char *buffer)
{
855
	return sprintf(buffer, "%u\n", module_refcount(mod));
L
Linus Torvalds 已提交
856 857 858
}

static struct module_attribute refcnt = {
859
	.attr = { .name = "refcnt", .mode = 0444 },
L
Linus Torvalds 已提交
860 861 862
	.show = show_refcnt,
};

A
Al Viro 已提交
863 864 865
void module_put(struct module *module)
{
	if (module) {
866
		preempt_disable();
867 868
		smp_wmb(); /* see comment in module_refcount */
		__this_cpu_inc(module->refptr->decs);
869

870
		trace_module_put(module, _RET_IP_);
A
Al Viro 已提交
871 872 873
		/* Maybe they're waiting for us to drop reference? */
		if (unlikely(!module_is_live(module)))
			wake_up_process(module->waiter);
874
		preempt_enable();
A
Al Viro 已提交
875 876 877 878
	}
}
EXPORT_SYMBOL(module_put);

L
Linus Torvalds 已提交
879
#else /* !CONFIG_MODULE_UNLOAD */
880
static inline void print_unload_info(struct seq_file *m, struct module *mod)
L
Linus Torvalds 已提交
881 882 883 884 885 886 887 888 889
{
	/* We don't know the usage count, or what modules are using. */
	seq_printf(m, " - -");
}

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

890
int ref_module(struct module *a, struct module *b)
L
Linus Torvalds 已提交
891
{
892
	return strong_try_module_get(b);
L
Linus Torvalds 已提交
893
}
894
EXPORT_SYMBOL_GPL(ref_module);
L
Linus Torvalds 已提交
895

896
static inline int module_unload_init(struct module *mod)
L
Linus Torvalds 已提交
897
{
898
	return 0;
L
Linus Torvalds 已提交
899 900 901
}
#endif /* CONFIG_MODULE_UNLOAD */

902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921
static ssize_t show_initstate(struct module_attribute *mattr,
			   struct module *mod, char *buffer)
{
	const char *state = "unknown";

	switch (mod->state) {
	case MODULE_STATE_LIVE:
		state = "live";
		break;
	case MODULE_STATE_COMING:
		state = "coming";
		break;
	case MODULE_STATE_GOING:
		state = "going";
		break;
	}
	return sprintf(buffer, "%s\n", state);
}

static struct module_attribute initstate = {
922
	.attr = { .name = "initstate", .mode = 0444 },
923 924 925
	.show = show_initstate,
};

926 927 928
static struct module_attribute *modinfo_attrs[] = {
	&modinfo_version,
	&modinfo_srcversion,
929
	&initstate,
930 931 932 933 934 935
#ifdef CONFIG_MODULE_UNLOAD
	&refcnt,
#endif
	NULL,
};

L
Linus Torvalds 已提交
936 937
static const char vermagic[] = VERMAGIC_STRING;

938
static int try_to_force_load(struct module *mod, const char *reason)
939 940
{
#ifdef CONFIG_MODULE_FORCE_LOAD
A
Andi Kleen 已提交
941
	if (!test_taint(TAINT_FORCED_MODULE))
942 943
		printk(KERN_WARNING "%s: %s: kernel tainted.\n",
		       mod->name, reason);
944 945 946 947 948 949 950
	add_taint_module(mod, TAINT_FORCED_MODULE);
	return 0;
#else
	return -ENOEXEC;
#endif
}

L
Linus Torvalds 已提交
951
#ifdef CONFIG_MODVERSIONS
952 953 954 955 956 957 958 959 960 961 962
/* 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
963 964 965 966
static int check_version(Elf_Shdr *sechdrs,
			 unsigned int versindex,
			 const char *symname,
			 struct module *mod, 
967 968
			 const unsigned long *crc,
			 const struct module *crc_owner)
L
Linus Torvalds 已提交
969 970 971 972 973 974 975 976
{
	unsigned int i, num_versions;
	struct modversion_info *versions;

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

977 978 979 980
	/* 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
981 982 983 984 985 986 987 988
	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;

989
		if (versions[i].crc == maybe_relocated(*crc, crc_owner))
L
Linus Torvalds 已提交
990 991
			return 1;
		DEBUGP("Found checksum %lX vs module %lX\n",
992
		       maybe_relocated(*crc, crc_owner), versions[i].crc);
993
		goto bad_version;
L
Linus Torvalds 已提交
994
	}
995

996 997 998
	printk(KERN_WARNING "%s: no symbol version for %s\n",
	       mod->name, symname);
	return 0;
999 1000 1001 1002 1003

bad_version:
	printk("%s: disagrees about version of symbol %s\n",
	       mod->name, symname);
	return 0;
L
Linus Torvalds 已提交
1004 1005 1006 1007 1008 1009 1010 1011
}

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

1012 1013
	/* Since this should be found in kernel (which can't be removed),
	 * no locking is necessary. */
1014 1015
	if (!find_symbol(MODULE_SYMBOL_PREFIX "module_layout", NULL,
			 &crc, true, false))
L
Linus Torvalds 已提交
1016
		BUG();
1017 1018
	return check_version(sechdrs, versindex, "module_layout", mod, crc,
			     NULL);
L
Linus Torvalds 已提交
1019 1020
}

1021 1022 1023
/* 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
1024
{
1025 1026 1027 1028
	if (has_crcs) {
		amagic += strcspn(amagic, " ");
		bmagic += strcspn(bmagic, " ");
	}
L
Linus Torvalds 已提交
1029 1030 1031 1032 1033 1034 1035
	return strcmp(amagic, bmagic) == 0;
}
#else
static inline int check_version(Elf_Shdr *sechdrs,
				unsigned int versindex,
				const char *symname,
				struct module *mod, 
1036 1037
				const unsigned long *crc,
				const struct module *crc_owner)
L
Linus Torvalds 已提交
1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048
{
	return 1;
}

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

1049 1050
static inline int same_magic(const char *amagic, const char *bmagic,
			     bool has_crcs)
L
Linus Torvalds 已提交
1051 1052 1053 1054 1055
{
	return strcmp(amagic, bmagic) == 0;
}
#endif /* CONFIG_MODVERSIONS */

1056
/* Resolve a symbol for this module.  I.e. if we find one, record usage. */
1057 1058 1059
static const struct kernel_symbol *resolve_symbol(Elf_Shdr *sechdrs,
						  unsigned int versindex,
						  const char *name,
1060 1061
						  struct module *mod,
						  char ownername[])
L
Linus Torvalds 已提交
1062 1063
{
	struct module *owner;
1064
	const struct kernel_symbol *sym;
L
Linus Torvalds 已提交
1065
	const unsigned long *crc;
1066
	int err;
L
Linus Torvalds 已提交
1067

1068
	mutex_lock(&module_mutex);
1069
	sym = find_symbol(name, &owner, &crc,
A
Andi Kleen 已提交
1070
			  !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
1071 1072 1073 1074 1075 1076
	if (!sym)
		goto unlock;

	if (!check_version(sechdrs, versindex, name, mod, crc, owner)) {
		sym = ERR_PTR(-EINVAL);
		goto getname;
L
Linus Torvalds 已提交
1077
	}
1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088

	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:
1089
	mutex_unlock(&module_mutex);
1090
	return sym;
L
Linus Torvalds 已提交
1091 1092
}

1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111
static const struct kernel_symbol *resolve_symbol_wait(Elf_Shdr *sechdrs,
						       unsigned int versindex,
						       const char *name,
						       struct module *mod)
{
	const struct kernel_symbol *ksym;
	char ownername[MODULE_NAME_LEN];

	if (wait_event_interruptible_timeout(module_wq,
			!IS_ERR(ksym = resolve_symbol(sechdrs, versindex, name,
						      mod, ownername)) ||
			PTR_ERR(ksym) != -EBUSY,
					     30 * HZ) <= 0) {
		printk(KERN_WARNING "%s: gave up waiting for init of module %s.\n",
		       mod->name, ownername);
	}
	return ksym;
}

L
Linus Torvalds 已提交
1112 1113 1114 1115
/*
 * /sys/module/foo/sections stuff
 * J. Corbet <corbet@lwn.net>
 */
1116
#if defined(CONFIG_KALLSYMS) && defined(CONFIG_SYSFS)
1117 1118 1119 1120 1121 1122

static inline bool sect_empty(const Elf_Shdr *sect)
{
	return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
}

1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136
struct module_sect_attr
{
	struct module_attribute mattr;
	char *name;
	unsigned long address;
};

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

L
Linus Torvalds 已提交
1137 1138 1139 1140 1141 1142 1143 1144
static ssize_t module_sect_show(struct module_attribute *mattr,
				struct module *mod, char *buf)
{
	struct module_sect_attr *sattr =
		container_of(mattr, struct module_sect_attr, mattr);
	return sprintf(buf, "0x%lx\n", sattr->address);
}

1145 1146
static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
{
1147
	unsigned int section;
1148 1149 1150 1151 1152 1153

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

L
Linus Torvalds 已提交
1154 1155 1156 1157 1158 1159 1160
static void add_sect_attrs(struct module *mod, unsigned int nsect,
		char *secstrings, Elf_Shdr *sechdrs)
{
	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
1161

L
Linus Torvalds 已提交
1162 1163
	/* Count loaded sections and allocate structures */
	for (i = 0; i < nsect; i++)
1164
		if (!sect_empty(&sechdrs[i]))
L
Linus Torvalds 已提交
1165 1166 1167 1168 1169
			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]);
1170 1171
	sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
	if (sect_attrs == NULL)
L
Linus Torvalds 已提交
1172 1173 1174 1175 1176 1177
		return;

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

1178
	sect_attrs->nsections = 0;
L
Linus Torvalds 已提交
1179 1180 1181
	sattr = &sect_attrs->attrs[0];
	gattr = &sect_attrs->grp.attrs[0];
	for (i = 0; i < nsect; i++) {
1182
		if (sect_empty(&sechdrs[i]))
1183
			continue;
L
Linus Torvalds 已提交
1184
		sattr->address = sechdrs[i].sh_addr;
1185 1186 1187 1188 1189
		sattr->name = kstrdup(secstrings + sechdrs[i].sh_name,
					GFP_KERNEL);
		if (sattr->name == NULL)
			goto out;
		sect_attrs->nsections++;
1190
		sysfs_attr_init(&sattr->mattr.attr);
L
Linus Torvalds 已提交
1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204
		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:
1205
	free_sect_attrs(sect_attrs);
L
Linus Torvalds 已提交
1206 1207 1208 1209 1210 1211 1212 1213 1214
}

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. */
1215
		free_sect_attrs(mod->sect_attrs);
L
Linus Torvalds 已提交
1216 1217 1218 1219
		mod->sect_attrs = NULL;
	}
}

R
Roland McGrath 已提交
1220 1221 1222 1223 1224 1225 1226 1227 1228 1229
/*
 * /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];
};

1230
static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
R
Roland McGrath 已提交
1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247
				 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]);
1248
		kobject_put(notes_attrs->dir);
R
Roland McGrath 已提交
1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259
	}
	kfree(notes_attrs);
}

static void add_notes_attrs(struct module *mod, unsigned int nsect,
			    char *secstrings, Elf_Shdr *sechdrs)
{
	unsigned int notes, loaded, i;
	struct module_notes_attrs *notes_attrs;
	struct bin_attribute *nattr;

1260 1261 1262 1263
	/* failed to create section attributes, so can't create notes */
	if (!mod->sect_attrs)
		return;

R
Roland McGrath 已提交
1264 1265 1266
	/* Count notes sections and allocate structures.  */
	notes = 0;
	for (i = 0; i < nsect; i++)
1267
		if (!sect_empty(&sechdrs[i]) &&
R
Roland McGrath 已提交
1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282
		    (sechdrs[i].sh_type == SHT_NOTE))
			++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];
	for (loaded = i = 0; i < nsect; ++i) {
1283
		if (sect_empty(&sechdrs[i]))
R
Roland McGrath 已提交
1284 1285
			continue;
		if (sechdrs[i].sh_type == SHT_NOTE) {
1286
			sysfs_bin_attr_init(nattr);
R
Roland McGrath 已提交
1287 1288 1289 1290 1291 1292 1293 1294 1295 1296
			nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
			nattr->attr.mode = S_IRUGO;
			nattr->size = sechdrs[i].sh_size;
			nattr->private = (void *) sechdrs[i].sh_addr;
			nattr->read = module_notes_read;
			++nattr;
		}
		++loaded;
	}

1297
	notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
R
Roland McGrath 已提交
1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318
	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
1319
#else
1320

L
Linus Torvalds 已提交
1321 1322 1323 1324 1325 1326 1327 1328
static inline void add_sect_attrs(struct module *mod, unsigned int nsect,
		char *sectstrings, Elf_Shdr *sechdrs)
{
}

static inline void remove_sect_attrs(struct module *mod)
{
}
R
Roland McGrath 已提交
1329 1330 1331 1332 1333 1334 1335 1336 1337

static inline void add_notes_attrs(struct module *mod, unsigned int nsect,
				   char *sectstrings, Elf_Shdr *sechdrs)
{
}

static inline void remove_notes_attrs(struct module *mod)
{
}
1338
#endif
L
Linus Torvalds 已提交
1339

1340
#ifdef CONFIG_SYSFS
1341 1342 1343 1344 1345 1346
static void add_usage_links(struct module *mod)
{
#ifdef CONFIG_MODULE_UNLOAD
	struct module_use *use;
	int nowarn;

1347
	mutex_lock(&module_mutex);
1348 1349 1350 1351
	list_for_each_entry(use, &mod->target_list, target_list) {
		nowarn = sysfs_create_link(use->target->holders_dir,
					   &mod->mkobj.kobj, mod->name);
	}
1352
	mutex_unlock(&module_mutex);
1353 1354 1355 1356 1357 1358 1359 1360
#endif
}

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

1361
	mutex_lock(&module_mutex);
1362 1363
	list_for_each_entry(use, &mod->target_list, target_list)
		sysfs_remove_link(use->target->holders_dir, mod->name);
1364
	mutex_unlock(&module_mutex);
1365 1366 1367
#endif
}

1368
static int module_add_modinfo_attrs(struct module *mod)
1369 1370
{
	struct module_attribute *attr;
1371
	struct module_attribute *temp_attr;
1372 1373 1374
	int error = 0;
	int i;

1375 1376 1377 1378 1379 1380 1381
	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;
1382 1383
	for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
		if (!attr->test ||
1384 1385
		    (attr->test && attr->test(mod))) {
			memcpy(temp_attr, attr, sizeof(*temp_attr));
1386
			sysfs_attr_init(&temp_attr->attr);
1387 1388 1389
			error = sysfs_create_file(&mod->mkobj.kobj,&temp_attr->attr);
			++temp_attr;
		}
1390 1391 1392 1393
	}
	return error;
}

1394
static void module_remove_modinfo_attrs(struct module *mod)
1395 1396 1397 1398
{
	struct module_attribute *attr;
	int i;

1399 1400 1401 1402
	for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
		/* pick a field to test for end of list */
		if (!attr->attr.name)
			break;
1403
		sysfs_remove_file(&mod->mkobj.kobj,&attr->attr);
1404 1405
		if (attr->free)
			attr->free(mod);
1406
	}
1407
	kfree(mod->modinfo_attrs);
1408
}
L
Linus Torvalds 已提交
1409

1410
static int mod_sysfs_init(struct module *mod)
L
Linus Torvalds 已提交
1411 1412
{
	int err;
1413
	struct kobject *kobj;
L
Linus Torvalds 已提交
1414

1415 1416
	if (!module_sysfs_initialized) {
		printk(KERN_ERR "%s: module sysfs not initialized\n",
1417 1418 1419 1420
		       mod->name);
		err = -EINVAL;
		goto out;
	}
1421 1422 1423 1424 1425 1426 1427 1428 1429

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

L
Linus Torvalds 已提交
1430
	mod->mkobj.mod = mod;
1431

1432 1433 1434 1435 1436 1437
	memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
	mod->mkobj.kobj.kset = module_kset;
	err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
				   "%s", mod->name);
	if (err)
		kobject_put(&mod->mkobj.kobj);
K
Kay Sievers 已提交
1438

1439
	/* delay uevent until full sysfs population */
K
Kay Sievers 已提交
1440 1441 1442 1443
out:
	return err;
}

1444
static int mod_sysfs_setup(struct module *mod,
K
Kay Sievers 已提交
1445 1446 1447 1448 1449
			   struct kernel_param *kparam,
			   unsigned int num_params)
{
	int err;

1450 1451 1452 1453
	err = mod_sysfs_init(mod);
	if (err)
		goto out;

1454
	mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1455 1456
	if (!mod->holders_dir) {
		err = -ENOMEM;
K
Kay Sievers 已提交
1457
		goto out_unreg;
1458
	}
K
Kay Sievers 已提交
1459

L
Linus Torvalds 已提交
1460 1461
	err = module_param_sysfs_setup(mod, kparam, num_params);
	if (err)
K
Kay Sievers 已提交
1462
		goto out_unreg_holders;
L
Linus Torvalds 已提交
1463

1464 1465
	err = module_add_modinfo_attrs(mod);
	if (err)
1466
		goto out_unreg_param;
1467

1468 1469
	add_usage_links(mod);

1470
	kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
L
Linus Torvalds 已提交
1471 1472
	return 0;

1473 1474
out_unreg_param:
	module_param_sysfs_remove(mod);
K
Kay Sievers 已提交
1475
out_unreg_holders:
1476
	kobject_put(mod->holders_dir);
K
Kay Sievers 已提交
1477
out_unreg:
1478
	kobject_put(&mod->mkobj.kobj);
1479
out:
L
Linus Torvalds 已提交
1480 1481
	return err;
}
1482 1483 1484 1485 1486 1487 1488 1489

static void mod_sysfs_fini(struct module *mod)
{
	kobject_put(&mod->mkobj.kobj);
}

#else /* CONFIG_SYSFS */

1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510
static inline int mod_sysfs_init(struct module *mod)
{
	return 0;
}

static inline int mod_sysfs_setup(struct module *mod,
			   struct kernel_param *kparam,
			   unsigned int num_params)
{
	return 0;
}

static inline int module_add_modinfo_attrs(struct module *mod)
{
	return 0;
}

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

1511 1512 1513 1514
static void mod_sysfs_fini(struct module *mod)
{
}

1515 1516 1517 1518
static void del_usage_links(struct module *mod)
{
}

1519
#endif /* CONFIG_SYSFS */
L
Linus Torvalds 已提交
1520 1521 1522

static void mod_kobject_remove(struct module *mod)
{
1523
	del_usage_links(mod);
1524
	module_remove_modinfo_attrs(mod);
L
Linus Torvalds 已提交
1525
	module_param_sysfs_remove(mod);
1526 1527
	kobject_put(mod->mkobj.drivers_dir);
	kobject_put(mod->holders_dir);
1528
	mod_sysfs_fini(mod);
L
Linus Torvalds 已提交
1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541
}

/*
 * unlink the module with the whole machine is stopped with interrupts off
 * - this defends against kallsyms not taking locks
 */
static int __unlink_module(void *_mod)
{
	struct module *mod = _mod;
	list_del(&mod->list);
	return 0;
}

1542
/* Free a module, remove from lists, etc. */
L
Linus Torvalds 已提交
1543 1544
static void free_module(struct module *mod)
{
1545 1546
	trace_module_free(mod);

L
Linus Torvalds 已提交
1547
	/* Delete from various lists */
1548
	mutex_lock(&module_mutex);
1549
	stop_machine(__unlink_module, mod, NULL);
1550
	mutex_unlock(&module_mutex);
R
Roland McGrath 已提交
1551
	remove_notes_attrs(mod);
L
Linus Torvalds 已提交
1552 1553 1554
	remove_sect_attrs(mod);
	mod_kobject_remove(mod);

1555 1556 1557
	/* Remove dynamic debug info */
	ddebug_remove_module(mod->name);

L
Linus Torvalds 已提交
1558 1559 1560 1561 1562 1563
	/* Arch-specific cleanup. */
	module_arch_cleanup(mod);

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

1564 1565 1566
	/* Free any allocated parameters. */
	destroy_params(mod->kp, mod->num_kp);

L
Linus Torvalds 已提交
1567 1568 1569
	/* This may be NULL, but that's OK */
	module_free(mod, mod->module_init);
	kfree(mod->args);
1570
	percpu_modfree(mod);
1571

I
Ingo Molnar 已提交
1572 1573 1574
	/* Free lock-classes: */
	lockdep_free_key_range(mod->module_core, mod->core_size);

L
Linus Torvalds 已提交
1575 1576
	/* Finally, free the core (containing the module structure) */
	module_free(mod, mod->module_core);
1577 1578 1579 1580

#ifdef CONFIG_MPU
	update_protections(current->mm);
#endif
L
Linus Torvalds 已提交
1581 1582 1583 1584 1585
}

void *__symbol_get(const char *symbol)
{
	struct module *owner;
1586
	const struct kernel_symbol *sym;
L
Linus Torvalds 已提交
1587

R
Rusty Russell 已提交
1588
	preempt_disable();
1589 1590 1591
	sym = find_symbol(symbol, &owner, NULL, true, true);
	if (sym && strong_try_module_get(owner))
		sym = NULL;
R
Rusty Russell 已提交
1592
	preempt_enable();
L
Linus Torvalds 已提交
1593

1594
	return sym ? (void *)sym->value : NULL;
L
Linus Torvalds 已提交
1595 1596 1597
}
EXPORT_SYMBOL_GPL(__symbol_get);

1598 1599
/*
 * Ensure that an exported symbol [global namespace] does not already exist
1600
 * in the kernel or in some other module's exported symbol table.
1601 1602
 *
 * You must hold the module_mutex.
1603 1604 1605
 */
static int verify_export_symbols(struct module *mod)
{
1606
	unsigned int i;
1607
	struct module *owner;
1608 1609 1610 1611 1612 1613 1614 1615
	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 },
1616
#ifdef CONFIG_UNUSED_SYMBOLS
1617 1618
		{ mod->unused_syms, mod->num_unused_syms },
		{ mod->unused_gpl_syms, mod->num_unused_gpl_syms },
1619
#endif
1620
	};
1621

1622 1623
	for (i = 0; i < ARRAY_SIZE(arr); i++) {
		for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
1624
			if (find_symbol(s->name, &owner, NULL, true, false)) {
1625 1626 1627 1628 1629 1630
				printk(KERN_ERR
				       "%s: exports duplicate symbol %s"
				       " (owned by %s)\n",
				       mod->name, s->name, module_name(owner));
				return -ENOEXEC;
			}
1631
		}
1632 1633
	}
	return 0;
1634 1635
}

1636
/* Change all symbols so that st_value encodes the pointer directly. */
L
Linus Torvalds 已提交
1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647
static int simplify_symbols(Elf_Shdr *sechdrs,
			    unsigned int symindex,
			    const char *strtab,
			    unsigned int versindex,
			    unsigned int pcpuindex,
			    struct module *mod)
{
	Elf_Sym *sym = (void *)sechdrs[symindex].sh_addr;
	unsigned long secbase;
	unsigned int i, n = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
	int ret = 0;
1648
	const struct kernel_symbol *ksym;
L
Linus Torvalds 已提交
1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667

	for (i = 1; i < n; i++) {
		switch (sym[i].st_shndx) {
		case SHN_COMMON:
			/* We compiled with -fno-common.  These are not
			   supposed to happen.  */
			DEBUGP("Common symbol: %s\n", strtab + sym[i].st_name);
			printk("%s: please compile with -fno-common\n",
			       mod->name);
			ret = -ENOEXEC;
			break;

		case SHN_ABS:
			/* Don't need to do anything */
			DEBUGP("Absolute symbol: 0x%08lx\n",
			       (long)sym[i].st_value);
			break;

		case SHN_UNDEF:
1668 1669 1670
			ksym = resolve_symbol_wait(sechdrs, versindex,
						   strtab + sym[i].st_name,
						   mod);
L
Linus Torvalds 已提交
1671
			/* Ok if resolved.  */
1672
			if (ksym && !IS_ERR(ksym)) {
1673
				sym[i].st_value = ksym->value;
L
Linus Torvalds 已提交
1674
				break;
1675 1676
			}

L
Linus Torvalds 已提交
1677
			/* Ok if weak.  */
1678
			if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
L
Linus Torvalds 已提交
1679 1680
				break;

1681 1682 1683 1684
			printk(KERN_WARNING "%s: Unknown symbol %s (err %li)\n",
			       mod->name, strtab + sym[i].st_name,
			       PTR_ERR(ksym));
			ret = PTR_ERR(ksym) ?: -ENOENT;
L
Linus Torvalds 已提交
1685 1686 1687 1688 1689
			break;

		default:
			/* Divert to percpu allocation if a percpu var. */
			if (sym[i].st_shndx == pcpuindex)
1690
				secbase = (unsigned long)mod_percpu(mod);
L
Linus Torvalds 已提交
1691 1692 1693 1694 1695 1696 1697 1698 1699 1700
			else
				secbase = sechdrs[sym[i].st_shndx].sh_addr;
			sym[i].st_value += secbase;
			break;
		}
	}

	return ret;
}

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
static int apply_relocations(struct module *mod,
			     Elf_Ehdr *hdr,
			     Elf_Shdr *sechdrs,
			     unsigned int symindex,
			     unsigned int strindex)
{
	unsigned int i;
	int err = 0;

	/* Now do relocations. */
	for (i = 1; i < hdr->e_shnum; i++) {
		const char *strtab = (char *)sechdrs[strindex].sh_addr;
		unsigned int info = sechdrs[i].sh_info;

		/* Not a valid relocation section? */
		if (info >= hdr->e_shnum)
			continue;

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

		if (sechdrs[i].sh_type == SHT_REL)
			err = apply_relocate(sechdrs, strtab, symindex, i, mod);
		else if (sechdrs[i].sh_type == SHT_RELA)
			err = apply_relocate_add(sechdrs, strtab, symindex, i,
						 mod);
		if (err < 0)
			break;
	}
	return err;
}

1734 1735 1736 1737 1738 1739 1740 1741
/* 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
1742
/* Update size with this section: return offset. */
1743 1744
static long get_offset(struct module *mod, unsigned int *size,
		       Elf_Shdr *sechdr, unsigned int section)
L
Linus Torvalds 已提交
1745 1746 1747
{
	long ret;

1748
	*size += arch_mod_section_prepend(mod, section);
L
Linus Torvalds 已提交
1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766 1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784
	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. */
static void layout_sections(struct module *mod,
			    const Elf_Ehdr *hdr,
			    Elf_Shdr *sechdrs,
			    const char *secstrings)
{
	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;

	for (i = 0; i < hdr->e_shnum; i++)
		sechdrs[i].sh_entsize = ~0UL;

	DEBUGP("Core section allocation order:\n");
	for (m = 0; m < ARRAY_SIZE(masks); ++m) {
		for (i = 0; i < hdr->e_shnum; ++i) {
			Elf_Shdr *s = &sechdrs[i];

			if ((s->sh_flags & masks[m][0]) != masks[m][0]
			    || (s->sh_flags & masks[m][1])
			    || s->sh_entsize != ~0UL
R
Rusty Russell 已提交
1785
			    || strstarts(secstrings + s->sh_name, ".init"))
L
Linus Torvalds 已提交
1786
				continue;
1787
			s->sh_entsize = get_offset(mod, &mod->core_size, s, i);
L
Linus Torvalds 已提交
1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801
			DEBUGP("\t%s\n", secstrings + s->sh_name);
		}
		if (m == 0)
			mod->core_text_size = mod->core_size;
	}

	DEBUGP("Init section allocation order:\n");
	for (m = 0; m < ARRAY_SIZE(masks); ++m) {
		for (i = 0; i < hdr->e_shnum; ++i) {
			Elf_Shdr *s = &sechdrs[i];

			if ((s->sh_flags & masks[m][0]) != masks[m][0]
			    || (s->sh_flags & masks[m][1])
			    || s->sh_entsize != ~0UL
R
Rusty Russell 已提交
1802
			    || !strstarts(secstrings + s->sh_name, ".init"))
L
Linus Torvalds 已提交
1803
				continue;
1804
			s->sh_entsize = (get_offset(mod, &mod->init_size, s, i)
L
Linus Torvalds 已提交
1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817
					 | INIT_OFFSET_MASK);
			DEBUGP("\t%s\n", secstrings + s->sh_name);
		}
		if (m == 0)
			mod->init_text_size = mod->init_size;
	}
}

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

1818
	if (!license_is_gpl_compatible(license)) {
A
Andi Kleen 已提交
1819
		if (!test_taint(TAINT_PROPRIETARY_MODULE))
1820
			printk(KERN_WARNING "%s: module license '%s' taints "
1821 1822
				"kernel.\n", mod->name, license);
		add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
L
Linus Torvalds 已提交
1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844
	}
}

/* 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;
}

1845
static char *get_modinfo(const Elf_Shdr *sechdrs,
L
Linus Torvalds 已提交
1846 1847 1848 1849 1850 1851 1852 1853 1854 1855 1856 1857 1858 1859
			 unsigned int info,
			 const char *tag)
{
	char *p;
	unsigned int taglen = strlen(tag);
	unsigned long size = sechdrs[info].sh_size;

	for (p = (char *)sechdrs[info].sh_addr; p; p = next_string(p, &size)) {
		if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
			return p + taglen + 1;
	}
	return NULL;
}

1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874
static void setup_modinfo(struct module *mod, Elf_Shdr *sechdrs,
			  unsigned int infoindex)
{
	struct module_attribute *attr;
	int i;

	for (i = 0; (attr = modinfo_attrs[i]); i++) {
		if (attr->setup)
			attr->setup(mod,
				    get_modinfo(sechdrs,
						infoindex,
						attr->attr.name));
	}
}

1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885
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
1886
#ifdef CONFIG_KALLSYMS
1887 1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899

/* 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)
{
	const struct kernel_symbol *ks = start;
	for (; ks < stop; ks++)
		if (strcmp(ks->name, name) == 0)
			return ks;
	return NULL;
}

1900 1901
static int is_exported(const char *name, unsigned long value,
		       const struct module *mod)
L
Linus Torvalds 已提交
1902
{
1903 1904 1905
	const struct kernel_symbol *ks;
	if (!mod)
		ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
1906
	else
1907 1908
		ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
	return ks != NULL && ks->value == value;
L
Linus Torvalds 已提交
1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945
}

/* As per nm */
static char elf_type(const Elf_Sym *sym,
		     Elf_Shdr *sechdrs,
		     const char *secstrings,
		     struct module *mod)
{
	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';
	}
R
Rusty Russell 已提交
1946
	if (strstarts(secstrings + sechdrs[sym->st_shndx].sh_name, ".debug"))
L
Linus Torvalds 已提交
1947 1948 1949 1950
		return 'n';
	return '?';
}

1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974
static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
                           unsigned int shnum)
{
	const Elf_Shdr *sec;

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

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

	return true;
}

static unsigned long layout_symtab(struct module *mod,
				   Elf_Shdr *sechdrs,
				   unsigned int symindex,
1975
				   unsigned int strindex,
1976
				   const Elf_Ehdr *hdr,
1977 1978 1979
				   const char *secstrings,
				   unsigned long *pstroffs,
				   unsigned long *strmap)
1980 1981 1982
{
	unsigned long symoffs;
	Elf_Shdr *symsect = sechdrs + symindex;
1983
	Elf_Shdr *strsect = sechdrs + strindex;
1984
	const Elf_Sym *src;
1985
	const char *strtab;
1986 1987 1988 1989 1990 1991 1992 1993 1994 1995
	unsigned int i, nsrc, ndst;

	/* 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,
					 symindex) | INIT_OFFSET_MASK;
	DEBUGP("\t%s\n", secstrings + symsect->sh_name);

	src = (void *)hdr + symsect->sh_offset;
	nsrc = symsect->sh_size / sizeof(*src);
1996
	strtab = (void *)hdr + strsect->sh_offset;
1997
	for (ndst = i = 1; i < nsrc; ++i, ++src)
1998 1999 2000 2001 2002
		if (is_core_symbol(src, sechdrs, hdr->e_shnum)) {
			unsigned int j = src->st_name;

			while(!__test_and_set_bit(j, strmap) && strtab[j])
				++j;
2003
			++ndst;
2004
		}
2005 2006 2007 2008 2009

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

2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020
	/* 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,
					 strindex) | INIT_OFFSET_MASK;
	DEBUGP("\t%s\n", secstrings + strsect->sh_name);

	/* Append room for core symbols' strings at end of core part. */
	*pstroffs = mod->core_size;
	__set_bit(0, strmap);
	mod->core_size += bitmap_weight(strmap, strsect->sh_size);

2021 2022 2023
	return symoffs;
}

L
Linus Torvalds 已提交
2024 2025
static void add_kallsyms(struct module *mod,
			 Elf_Shdr *sechdrs,
2026
			 unsigned int shnum,
L
Linus Torvalds 已提交
2027 2028
			 unsigned int symindex,
			 unsigned int strindex,
2029
			 unsigned long symoffs,
2030 2031 2032
			 unsigned long stroffs,
			 const char *secstrings,
			 unsigned long *strmap)
L
Linus Torvalds 已提交
2033
{
2034 2035 2036
	unsigned int i, ndst;
	const Elf_Sym *src;
	Elf_Sym *dst;
2037
	char *s;
L
Linus Torvalds 已提交
2038 2039 2040 2041 2042 2043 2044 2045 2046

	mod->symtab = (void *)sechdrs[symindex].sh_addr;
	mod->num_symtab = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
	mod->strtab = (void *)sechdrs[strindex].sh_addr;

	/* Set types up while we still have access to sections. */
	for (i = 0; i < mod->num_symtab; i++)
		mod->symtab[i].st_info
			= elf_type(&mod->symtab[i], sechdrs, secstrings, mod);
2047 2048 2049 2050 2051 2052 2053 2054

	mod->core_symtab = dst = mod->module_core + symoffs;
	src = mod->symtab;
	*dst = *src;
	for (ndst = i = 1; i < mod->num_symtab; ++i, ++src) {
		if (!is_core_symbol(src, sechdrs, shnum))
			continue;
		dst[ndst] = *src;
2055
		dst[ndst].st_name = bitmap_weight(strmap, dst[ndst].st_name);
2056 2057 2058
		++ndst;
	}
	mod->core_num_syms = ndst;
2059 2060 2061 2062 2063

	mod->core_strtab = s = mod->module_core + stroffs;
	for (*s = 0, i = 1; i < sechdrs[strindex].sh_size; ++i)
		if (test_bit(i, strmap))
			*++s = mod->strtab[i];
L
Linus Torvalds 已提交
2064 2065
}
#else
2066 2067 2068
static inline unsigned long layout_symtab(struct module *mod,
					  Elf_Shdr *sechdrs,
					  unsigned int symindex,
2069
					  unsigned int strindex,
2070
					  const Elf_Ehdr *hdr,
2071 2072 2073
					  const char *secstrings,
					  unsigned long *pstroffs,
					  unsigned long *strmap)
2074
{
2075
	return 0;
2076
}
2077

L
Linus Torvalds 已提交
2078 2079
static inline void add_kallsyms(struct module *mod,
				Elf_Shdr *sechdrs,
2080
				unsigned int shnum,
L
Linus Torvalds 已提交
2081 2082
				unsigned int symindex,
				unsigned int strindex,
2083
				unsigned long symoffs,
2084 2085 2086
				unsigned long stroffs,
				const char *secstrings,
				const unsigned long *strmap)
L
Linus Torvalds 已提交
2087 2088 2089 2090
{
}
#endif /* CONFIG_KALLSYMS */

2091
static void dynamic_debug_setup(struct _ddebug *debug, unsigned int num)
2092
{
2093 2094 2095 2096 2097
#ifdef CONFIG_DYNAMIC_DEBUG
	if (ddebug_add_module(debug, num, debug->modname))
		printk(KERN_ERR "dynamic debug error adding module: %s\n",
					debug->modname);
#endif
R
Rusty Russell 已提交
2098
}
2099

2100 2101 2102 2103 2104 2105
static void dynamic_debug_remove(struct _ddebug *debug)
{
	if (debug)
		ddebug_remove_module(debug->modname);
}

2106 2107 2108 2109 2110
static void *module_alloc_update_bounds(unsigned long size)
{
	void *ret = module_alloc(size);

	if (ret) {
2111
		mutex_lock(&module_mutex);
2112 2113 2114 2115 2116
		/* 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;
2117
		mutex_unlock(&module_mutex);
2118 2119 2120 2121
	}
	return ret;
}

C
Catalin Marinas 已提交
2122 2123
#ifdef CONFIG_DEBUG_KMEMLEAK
static void kmemleak_load_module(struct module *mod, Elf_Ehdr *hdr,
2124 2125
				 const Elf_Shdr *sechdrs,
				 const char *secstrings)
C
Catalin Marinas 已提交
2126 2127 2128 2129
{
	unsigned int i;

	/* only scan the sections containing data */
2130
	kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
C
Catalin Marinas 已提交
2131 2132 2133 2134 2135 2136 2137 2138

	for (i = 1; i < hdr->e_shnum; i++) {
		if (!(sechdrs[i].sh_flags & SHF_ALLOC))
			continue;
		if (strncmp(secstrings + sechdrs[i].sh_name, ".data", 5) != 0
		    && strncmp(secstrings + sechdrs[i].sh_name, ".bss", 4) != 0)
			continue;

2139
		kmemleak_scan_area((void *)sechdrs[i].sh_addr,
C
Catalin Marinas 已提交
2140 2141 2142 2143 2144
				   sechdrs[i].sh_size, GFP_KERNEL);
	}
}
#else
static inline void kmemleak_load_module(struct module *mod, Elf_Ehdr *hdr,
2145 2146
					Elf_Shdr *sechdrs,
					const char *secstrings)
C
Catalin Marinas 已提交
2147 2148 2149 2150
{
}
#endif

2151 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 2172 2173 2174 2175 2176 2177 2178 2179 2180 2181 2182 2183 2184 2185 2186 2187 2188 2189 2190 2191 2192 2193 2194 2195 2196 2197 2198 2199 2200 2201 2202 2203 2204 2205 2206 2207 2208 2209 2210 2211 2212 2213 2214
static int copy_and_check(Elf_Ehdr **hdrp,
			  const void __user *umod, unsigned long len)
{
	int err;
	Elf_Ehdr *hdr;

	if (len < sizeof(*hdr))
		return -ENOEXEC;

	/* Suck in entire file: we'll want most of it. */
	/* vmalloc barfs on "unusual" numbers.  Check here */
	if (len > 64 * 1024 * 1024 || (hdr = *hdrp = vmalloc(len)) == NULL)
		return -ENOMEM;

	if (copy_from_user(hdr, umod, len) != 0) {
		err = -EFAULT;
		goto free_hdr;
	}

	/* Sanity checks against insmoding binaries or wrong arch,
	   weird elf version */
	if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0
	    || hdr->e_type != ET_REL
	    || !elf_check_arch(hdr)
	    || hdr->e_shentsize != sizeof(Elf_Shdr)) {
		err = -ENOEXEC;
		goto free_hdr;
	}

	if (len < hdr->e_shoff + hdr->e_shnum * sizeof(Elf_Shdr)) {
		err = -ENOEXEC;
		goto free_hdr;
	}
	return 0;

free_hdr:
	vfree(hdr);
	return err;
}

static int check_modinfo(struct module *mod,
			 const Elf_Shdr *sechdrs,
			 unsigned int infoindex, unsigned int versindex)
{
	const char *modmagic = get_modinfo(sechdrs, infoindex, "vermagic");
	int err;

	/* This is allowed: modprobe --force will invalidate it. */
	if (!modmagic) {
		err = try_to_force_load(mod, "bad vermagic");
		if (err)
			return err;
	} else if (!same_magic(modmagic, vermagic, versindex)) {
		printk(KERN_ERR "%s: version magic '%s' should be '%s'\n",
		       mod->name, modmagic, vermagic);
		return -ENOEXEC;
	}

	if (get_modinfo(sechdrs, infoindex, "staging")) {
		add_taint_module(mod, TAINT_CRAP);
		printk(KERN_WARNING "%s: module is from the staging directory,"
		       " the quality is unknown, you have been warned.\n",
		       mod->name);
	}
2215 2216 2217 2218

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

2219 2220 2221
	return 0;
}

L
Linus Torvalds 已提交
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 2250 2251 2252 2253 2254 2255 2256 2257 2258 2259 2260 2261 2262 2263 2264 2265 2266 2267 2268 2269 2270 2271 2272 2273 2274 2275 2276 2277 2278 2279 2280 2281 2282 2283 2284
static void find_module_sections(struct module *mod, Elf_Ehdr *hdr,
				 Elf_Shdr *sechdrs, const char *secstrings)
{
	mod->kp = section_objs(hdr, sechdrs, secstrings, "__param",
			       sizeof(*mod->kp), &mod->num_kp);
	mod->syms = section_objs(hdr, sechdrs, secstrings, "__ksymtab",
				 sizeof(*mod->syms), &mod->num_syms);
	mod->crcs = section_addr(hdr, sechdrs, secstrings, "__kcrctab");
	mod->gpl_syms = section_objs(hdr, sechdrs, secstrings, "__ksymtab_gpl",
				     sizeof(*mod->gpl_syms),
				     &mod->num_gpl_syms);
	mod->gpl_crcs = section_addr(hdr, sechdrs, secstrings, "__kcrctab_gpl");
	mod->gpl_future_syms = section_objs(hdr, sechdrs, secstrings,
					    "__ksymtab_gpl_future",
					    sizeof(*mod->gpl_future_syms),
					    &mod->num_gpl_future_syms);
	mod->gpl_future_crcs = section_addr(hdr, sechdrs, secstrings,
					    "__kcrctab_gpl_future");

#ifdef CONFIG_UNUSED_SYMBOLS
	mod->unused_syms = section_objs(hdr, sechdrs, secstrings,
					"__ksymtab_unused",
					sizeof(*mod->unused_syms),
					&mod->num_unused_syms);
	mod->unused_crcs = section_addr(hdr, sechdrs, secstrings,
					"__kcrctab_unused");
	mod->unused_gpl_syms = section_objs(hdr, sechdrs, secstrings,
					    "__ksymtab_unused_gpl",
					    sizeof(*mod->unused_gpl_syms),
					    &mod->num_unused_gpl_syms);
	mod->unused_gpl_crcs = section_addr(hdr, sechdrs, secstrings,
					    "__kcrctab_unused_gpl");
#endif
#ifdef CONFIG_CONSTRUCTORS
	mod->ctors = section_objs(hdr, sechdrs, secstrings, ".ctors",
				  sizeof(*mod->ctors), &mod->num_ctors);
#endif

#ifdef CONFIG_TRACEPOINTS
	mod->tracepoints = section_objs(hdr, sechdrs, secstrings,
					"__tracepoints",
					sizeof(*mod->tracepoints),
					&mod->num_tracepoints);
#endif
#ifdef CONFIG_EVENT_TRACING
	mod->trace_events = section_objs(hdr, sechdrs, secstrings,
					 "_ftrace_events",
					 sizeof(*mod->trace_events),
					 &mod->num_trace_events);
	/*
	 * This section contains pointers to allocated objects in the trace
	 * code and not scanning it leads to false positives.
	 */
	kmemleak_scan_area(mod->trace_events, sizeof(*mod->trace_events) *
			   mod->num_trace_events, GFP_KERNEL);
#endif
#ifdef CONFIG_FTRACE_MCOUNT_RECORD
	/* sechdrs[0].sh_size is always zero */
	mod->ftrace_callsites = section_objs(hdr, sechdrs, secstrings,
					     "__mcount_loc",
					     sizeof(*mod->ftrace_callsites),
					     &mod->num_ftrace_callsites);
#endif
2285 2286 2287 2288

	if (section_addr(hdr, sechdrs, secstrings, "__obsparm"))
		printk(KERN_WARNING "%s: Ignoring obsolete parameters\n",
		       mod->name);
L
Linus Torvalds 已提交
2289 2290
}

2291 2292 2293 2294 2295 2296 2297 2298 2299 2300 2301 2302 2303 2304 2305 2306 2307 2308 2309 2310 2311 2312 2313 2314 2315 2316 2317 2318 2319 2320 2321 2322 2323 2324 2325 2326 2327 2328 2329 2330 2331 2332 2333 2334 2335 2336 2337 2338 2339 2340 2341 2342 2343 2344 2345 2346 2347 2348 2349 2350 2351 2352 2353 2354
static struct module *move_module(struct module *mod,
				  Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
				  const char *secstrings, unsigned modindex)
{
	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)
		return ERR_PTR(-ENOMEM);

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

	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 && mod->init_size) {
		module_free(mod, mod->module_core);
		return ERR_PTR(-ENOMEM);
	}
	memset(ptr, 0, mod->init_size);
	mod->module_init = ptr;

	/* Transfer each section which specifies SHF_ALLOC */
	DEBUGP("final section addresses:\n");
	for (i = 0; i < hdr->e_shnum; i++) {
		void *dest;

		if (!(sechdrs[i].sh_flags & SHF_ALLOC))
			continue;

		if (sechdrs[i].sh_entsize & INIT_OFFSET_MASK)
			dest = mod->module_init
				+ (sechdrs[i].sh_entsize & ~INIT_OFFSET_MASK);
		else
			dest = mod->module_core + sechdrs[i].sh_entsize;

		if (sechdrs[i].sh_type != SHT_NOBITS)
			memcpy(dest, (void *)sechdrs[i].sh_addr,
			       sechdrs[i].sh_size);
		/* Update sh_addr to point to copy in image. */
		sechdrs[i].sh_addr = (unsigned long)dest;
		DEBUGP("\t0x%lx %s\n",
		       sechdrs[i].sh_addr, secstrings + sechdrs[i].sh_name);
	}
	/* Module has been moved. */
	mod = (void *)sechdrs[modindex].sh_addr;
	kmemleak_load_module(mod, hdr, sechdrs, secstrings);
	return mod;
}

2355 2356 2357 2358 2359 2360 2361 2362 2363 2364 2365 2366 2367 2368 2369 2370 2371 2372 2373 2374 2375 2376 2377 2378 2379 2380 2381 2382 2383 2384 2385 2386 2387 2388 2389 2390 2391 2392 2393 2394 2395 2396 2397 2398 2399 2400 2401 2402 2403 2404 2405 2406 2407 2408
static int check_module_license_and_versions(struct module *mod,
					     Elf_Shdr *sechdrs)
{
	/*
	 * 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)
		add_taint(TAINT_PROPRIETARY_MODULE);

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

#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);
}

L
Linus Torvalds 已提交
2409 2410
/* Allocate and load the module: note that size of section 0 is always
   zero, and we rely on this for optional sections. */
2411
static noinline struct module *load_module(void __user *umod,
L
Linus Torvalds 已提交
2412 2413 2414 2415 2416
				  unsigned long len,
				  const char __user *uargs)
{
	Elf_Ehdr *hdr;
	Elf_Shdr *sechdrs;
2417
	char *secstrings, *args, *strtab = NULL;
A
Andrew Morton 已提交
2418 2419 2420
	unsigned int i;
	unsigned int symindex = 0;
	unsigned int strindex = 0;
R
Rusty Russell 已提交
2421
	unsigned int modindex, versindex, infoindex, pcpuindex;
L
Linus Torvalds 已提交
2422
	struct module *mod;
2423
	long err;
2424
	unsigned long symoffs, stroffs, *strmap;
2425
	void __percpu *percpu;
2426 2427
	struct _ddebug *debug = NULL;
	unsigned int num_debug = 0;
2428

L
Linus Torvalds 已提交
2429 2430 2431
	DEBUGP("load_module: umod=%p, len=%lu, uargs=%p\n",
	       umod, len, uargs);

2432 2433 2434
	err = copy_and_check(&hdr, umod, len);
	if (err)
		return ERR_PTR(err);
L
Linus Torvalds 已提交
2435 2436 2437 2438 2439 2440 2441 2442 2443 2444 2445 2446 2447 2448 2449 2450 2451 2452 2453 2454 2455 2456 2457

	/* Convenience variables */
	sechdrs = (void *)hdr + hdr->e_shoff;
	secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
	sechdrs[0].sh_addr = 0;

	for (i = 1; i < hdr->e_shnum; i++) {
		if (sechdrs[i].sh_type != SHT_NOBITS
		    && len < sechdrs[i].sh_offset + sechdrs[i].sh_size)
			goto truncated;

		/* Mark all sections sh_addr with their address in the
		   temporary image. */
		sechdrs[i].sh_addr = (size_t)hdr + sechdrs[i].sh_offset;

		/* Internal symbols and strings. */
		if (sechdrs[i].sh_type == SHT_SYMTAB) {
			symindex = i;
			strindex = sechdrs[i].sh_link;
			strtab = (char *)hdr + sechdrs[strindex].sh_offset;
		}
#ifndef CONFIG_MODULE_UNLOAD
		/* Don't load .exit sections */
R
Rusty Russell 已提交
2458
		if (strstarts(secstrings+sechdrs[i].sh_name, ".exit"))
L
Linus Torvalds 已提交
2459 2460 2461 2462 2463 2464 2465 2466 2467 2468 2469
			sechdrs[i].sh_flags &= ~(unsigned long)SHF_ALLOC;
#endif
	}

	modindex = find_sec(hdr, sechdrs, secstrings,
			    ".gnu.linkonce.this_module");
	if (!modindex) {
		printk(KERN_WARNING "No module found in object\n");
		err = -ENOEXEC;
		goto free_hdr;
	}
R
Rusty Russell 已提交
2470
	/* This is temporary: point mod into copy of data. */
L
Linus Torvalds 已提交
2471 2472 2473 2474 2475 2476 2477 2478 2479 2480 2481 2482 2483
	mod = (void *)sechdrs[modindex].sh_addr;

	if (symindex == 0) {
		printk(KERN_WARNING "%s: module has no symbols (stripped?)\n",
		       mod->name);
		err = -ENOEXEC;
		goto free_hdr;
	}

	versindex = find_sec(hdr, sechdrs, secstrings, "__versions");
	infoindex = find_sec(hdr, sechdrs, secstrings, ".modinfo");
	pcpuindex = find_pcpusec(hdr, sechdrs, secstrings);

2484
	/* Don't keep modinfo and version sections. */
L
Linus Torvalds 已提交
2485
	sechdrs[infoindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
2486
	sechdrs[versindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
L
Linus Torvalds 已提交
2487 2488 2489 2490 2491 2492 2493

	/* Check module struct version now, before we try to use module. */
	if (!check_modstruct_version(sechdrs, versindex, mod)) {
		err = -ENOEXEC;
		goto free_hdr;
	}

2494 2495
	err = check_modinfo(mod, sechdrs, infoindex, versindex);
	if (err)
L
Linus Torvalds 已提交
2496
		goto free_hdr;
2497

L
Linus Torvalds 已提交
2498
	/* Now copy in args */
2499 2500 2501
	args = strndup_user(uargs, ~0UL >> 1);
	if (IS_ERR(args)) {
		err = PTR_ERR(args);
L
Linus Torvalds 已提交
2502 2503
		goto free_hdr;
	}
2504

2505 2506 2507 2508 2509 2510 2511
	strmap = kzalloc(BITS_TO_LONGS(sechdrs[strindex].sh_size)
			 * sizeof(long), GFP_KERNEL);
	if (!strmap) {
		err = -ENOMEM;
		goto free_mod;
	}

L
Linus Torvalds 已提交
2512 2513 2514 2515 2516 2517 2518 2519 2520
	mod->state = MODULE_STATE_COMING;

	/* Allow arches to frob section contents and sizes.  */
	err = module_frob_arch_sections(hdr, sechdrs, secstrings, mod);
	if (err < 0)
		goto free_mod;

	if (pcpuindex) {
		/* We have a special allocation for this section. */
2521 2522 2523
		err = percpu_modalloc(mod, sechdrs[pcpuindex].sh_size,
				      sechdrs[pcpuindex].sh_addralign);
		if (err)
2524
			goto free_mod;
L
Linus Torvalds 已提交
2525 2526
		sechdrs[pcpuindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
	}
2527 2528
	/* Keep this around for failure path. */
	percpu = mod_percpu(mod);
L
Linus Torvalds 已提交
2529 2530 2531 2532 2533

	/* 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. */
	layout_sections(mod, hdr, sechdrs, secstrings);
2534 2535
	symoffs = layout_symtab(mod, sechdrs, symindex, strindex, hdr,
				secstrings, &stroffs, strmap);
L
Linus Torvalds 已提交
2536

2537 2538 2539 2540
	/* Allocate and move to the final place */
	mod = move_module(mod, hdr, sechdrs, secstrings, modindex);
	if (IS_ERR(mod)) {
		err = PTR_ERR(mod);
L
Linus Torvalds 已提交
2541 2542 2543 2544
		goto free_percpu;
	}

	/* Now we've moved module, initialize linked lists, etc. */
2545 2546 2547
	err = module_unload_init(mod);
	if (err)
		goto free_init;
L
Linus Torvalds 已提交
2548

2549 2550 2551
	/* Now we've got everything in the final locations, we can
	 * find optional sections. */
	find_module_sections(mod, hdr, sechdrs, secstrings);
2552

2553 2554 2555
	err = check_module_license_and_versions(mod, sechdrs);
	if (err)
		goto free_unload;
2556

2557 2558 2559
	/* Set up MODINFO_ATTR fields */
	setup_modinfo(mod, sechdrs, infoindex);

L
Linus Torvalds 已提交
2560 2561 2562 2563 2564 2565
	/* Fix up syms, so that st_value is a pointer to location. */
	err = simplify_symbols(sechdrs, symindex, strtab, versindex, pcpuindex,
			       mod);
	if (err < 0)
		goto cleanup;

2566 2567 2568
	err = apply_relocations(mod, hdr, sechdrs, symindex, strindex);
	if (err < 0)
		goto cleanup;
L
Linus Torvalds 已提交
2569 2570

  	/* Set up and sort exception table */
R
Rusty Russell 已提交
2571 2572 2573
	mod->extable = section_objs(hdr, sechdrs, secstrings, "__ex_table",
				    sizeof(*mod->extable), &mod->num_exentries);
	sort_extable(mod->extable, mod->extable + mod->num_exentries);
L
Linus Torvalds 已提交
2574 2575

	/* Finally, copy percpu area over. */
2576
	percpu_modcopy(mod, (void *)sechdrs[pcpuindex].sh_addr,
L
Linus Torvalds 已提交
2577 2578
		       sechdrs[pcpuindex].sh_size);

2579
	add_kallsyms(mod, sechdrs, hdr->e_shnum, symindex, strindex,
2580 2581 2582
		     symoffs, stroffs, secstrings, strmap);
	kfree(strmap);
	strmap = NULL;
L
Linus Torvalds 已提交
2583

2584
	if (!mod->taints)
R
Rusty Russell 已提交
2585 2586
		debug = section_objs(hdr, sechdrs, secstrings, "__verbose",
				     sizeof(*debug), &num_debug);
2587

L
Linus Torvalds 已提交
2588 2589 2590 2591
	err = module_finalize(hdr, sechdrs, mod);
	if (err < 0)
		goto cleanup;

2592
	flush_module_icache(mod);
2593

L
Linus Torvalds 已提交
2594
	mod->args = args;
R
Rusty Russell 已提交
2595

2596
	/* Now sew it into the lists so we can get lockdep and oops
2597 2598 2599 2600 2601 2602
	 * info during argument parsing.  Noone should access us, since
	 * strong_try_module_get() will fail.
	 * lockdep/oops can run asynchronous, so use the RCU list insertion
	 * function to insert in a way safe to concurrent readers.
	 * The mutex protects against concurrent writers.
	 */
2603
	mutex_lock(&module_mutex);
2604 2605
	if (find_module(mod->name)) {
		err = -EEXIST;
2606
		goto unlock;
2607 2608
	}

2609 2610 2611
	if (debug)
		dynamic_debug_setup(debug, num_debug);

2612 2613 2614
	/* Find duplicate symbols */
	err = verify_export_symbols(mod);
	if (err < 0)
2615
		goto ddebug;
2616

2617
	list_add_rcu(&mod->list, &modules);
2618
	mutex_unlock(&module_mutex);
2619

2620
	err = parse_args(mod->name, mod->args, mod->kp, mod->num_kp, NULL);
L
Linus Torvalds 已提交
2621
	if (err < 0)
2622
		goto unlink;
L
Linus Torvalds 已提交
2623

2624
	err = mod_sysfs_setup(mod, mod->kp, mod->num_kp);
L
Linus Torvalds 已提交
2625
	if (err < 0)
2626
		goto unlink;
2627

L
Linus Torvalds 已提交
2628
	add_sect_attrs(mod, hdr->e_shnum, secstrings, sechdrs);
R
Roland McGrath 已提交
2629
	add_notes_attrs(mod, hdr->e_shnum, secstrings, sechdrs);
L
Linus Torvalds 已提交
2630 2631 2632 2633

	/* Get rid of temporary copy */
	vfree(hdr);

2634 2635
	trace_module_load(mod);

L
Linus Torvalds 已提交
2636 2637 2638
	/* Done! */
	return mod;

2639
 unlink:
2640
	mutex_lock(&module_mutex);
2641 2642
	/* Unlink carefully: kallsyms could be walking list. */
	list_del_rcu(&mod->list);
2643 2644
 ddebug:
	dynamic_debug_remove(debug);
2645
 unlock:
2646
	mutex_unlock(&module_mutex);
2647
	synchronize_sched();
L
Linus Torvalds 已提交
2648 2649
	module_arch_cleanup(mod);
 cleanup:
2650
	free_modinfo(mod);
2651
 free_unload:
L
Linus Torvalds 已提交
2652
	module_unload_free(mod);
2653
 free_init:
L
Linus Torvalds 已提交
2654 2655
	module_free(mod, mod->module_init);
	module_free(mod, mod->module_core);
2656
	/* mod will be freed with core. Don't access it beyond this line! */
L
Linus Torvalds 已提交
2657
 free_percpu:
2658
	free_percpu(percpu);
L
Linus Torvalds 已提交
2659 2660
 free_mod:
	kfree(args);
2661
	kfree(strmap);
L
Linus Torvalds 已提交
2662 2663
 free_hdr:
	vfree(hdr);
2664
	return ERR_PTR(err);
L
Linus Torvalds 已提交
2665 2666 2667 2668 2669 2670 2671

 truncated:
	printk(KERN_ERR "Module len %lu truncated\n", len);
	err = -ENOEXEC;
	goto free_hdr;
}

2672 2673 2674 2675 2676 2677 2678 2679 2680 2681 2682
/* 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
}

L
Linus Torvalds 已提交
2683
/* This is where the real work happens */
2684 2685
SYSCALL_DEFINE3(init_module, void __user *, umod,
		unsigned long, len, const char __user *, uargs)
L
Linus Torvalds 已提交
2686 2687 2688 2689 2690
{
	struct module *mod;
	int ret = 0;

	/* Must have permission */
2691
	if (!capable(CAP_SYS_MODULE) || modules_disabled)
L
Linus Torvalds 已提交
2692 2693 2694 2695
		return -EPERM;

	/* Do all the hard work */
	mod = load_module(umod, len, uargs);
2696
	if (IS_ERR(mod))
L
Linus Torvalds 已提交
2697 2698
		return PTR_ERR(mod);

2699 2700
	blocking_notifier_call_chain(&module_notify_list,
			MODULE_STATE_COMING, mod);
L
Linus Torvalds 已提交
2701

2702
	do_mod_ctors(mod);
L
Linus Torvalds 已提交
2703 2704
	/* Start the module */
	if (mod->init != NULL)
2705
		ret = do_one_initcall(mod->init);
L
Linus Torvalds 已提交
2706 2707 2708 2709
	if (ret < 0) {
		/* Init routine failed: abort.  Try to protect us from
                   buggy refcounters. */
		mod->state = MODULE_STATE_GOING;
2710
		synchronize_sched();
R
Rusty Russell 已提交
2711
		module_put(mod);
2712 2713
		blocking_notifier_call_chain(&module_notify_list,
					     MODULE_STATE_GOING, mod);
R
Rusty Russell 已提交
2714
		free_module(mod);
2715
		wake_up(&module_wq);
L
Linus Torvalds 已提交
2716 2717
		return ret;
	}
2718
	if (ret > 0) {
2719 2720 2721
		printk(KERN_WARNING
"%s: '%s'->init suspiciously returned %d, it should follow 0/-E convention\n"
"%s: loading module anyway...\n",
2722 2723 2724 2725
		       __func__, mod->name, ret,
		       __func__);
		dump_stack();
	}
L
Linus Torvalds 已提交
2726

2727
	/* Now it's a first class citizen!  Wake up anyone waiting for it. */
L
Linus Torvalds 已提交
2728
	mod->state = MODULE_STATE_LIVE;
2729
	wake_up(&module_wq);
2730 2731
	blocking_notifier_call_chain(&module_notify_list,
				     MODULE_STATE_LIVE, mod);
2732

2733 2734 2735
	/* We need to finish all async code before the module init sequence is done */
	async_synchronize_full();

2736
	mutex_lock(&module_mutex);
L
Linus Torvalds 已提交
2737 2738
	/* Drop initial reference. */
	module_put(mod);
2739
	trim_init_extable(mod);
2740 2741 2742
#ifdef CONFIG_KALLSYMS
	mod->num_symtab = mod->core_num_syms;
	mod->symtab = mod->core_symtab;
2743
	mod->strtab = mod->core_strtab;
2744
#endif
L
Linus Torvalds 已提交
2745 2746 2747 2748
	module_free(mod, mod->module_init);
	mod->module_init = NULL;
	mod->init_size = 0;
	mod->init_text_size = 0;
2749
	mutex_unlock(&module_mutex);
L
Linus Torvalds 已提交
2750 2751 2752 2753 2754 2755 2756 2757 2758 2759 2760 2761 2762 2763 2764 2765

	return 0;
}

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 $d.
 */
static inline int is_arm_mapping_symbol(const char *str)
{
D
Daniel Walker 已提交
2766
	return str[0] == '$' && strchr("atd", str[1])
L
Linus Torvalds 已提交
2767 2768 2769 2770 2771 2772 2773 2774 2775 2776 2777 2778
	       && (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 */
2779
	if (within_module_init(addr, mod))
L
Linus Torvalds 已提交
2780
		nextval = (unsigned long)mod->module_init+mod->init_text_size;
D
Daniel Walker 已提交
2781
	else
L
Linus Torvalds 已提交
2782 2783 2784
		nextval = (unsigned long)mod->module_core+mod->core_text_size;

	/* Scan for closest preceeding symbol, and next symbol. (ELF
D
Daniel Walker 已提交
2785
	   starts real symbols at 1). */
L
Linus Torvalds 已提交
2786 2787 2788 2789 2790 2791 2792 2793 2794 2795 2796 2797 2798 2799 2800 2801 2802 2803 2804 2805 2806
	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
2807 2808 2809 2810
	if (size)
		*size = nextval - mod->symtab[best].st_value;
	if (offset)
		*offset = addr - mod->symtab[best].st_value;
L
Linus Torvalds 已提交
2811 2812 2813
	return mod->strtab + mod->symtab[best].st_name;
}

2814 2815
/* For kallsyms to ask for address resolution.  NULL means not found.  Careful
 * not to lock to avoid deadlock on oopses, simply disable preemption. */
2816
const char *module_address_lookup(unsigned long addr,
2817 2818 2819 2820
			    unsigned long *size,
			    unsigned long *offset,
			    char **modname,
			    char *namebuf)
L
Linus Torvalds 已提交
2821 2822
{
	struct module *mod;
2823
	const char *ret = NULL;
L
Linus Torvalds 已提交
2824

2825
	preempt_disable();
2826
	list_for_each_entry_rcu(mod, &modules, list) {
2827 2828
		if (within_module_init(addr, mod) ||
		    within_module_core(addr, mod)) {
2829 2830
			if (modname)
				*modname = mod->name;
2831 2832
			ret = get_ksymbol(mod, addr, size, offset);
			break;
L
Linus Torvalds 已提交
2833 2834
		}
	}
2835 2836 2837 2838 2839
	/* Make a copy in here where it's safe */
	if (ret) {
		strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
		ret = namebuf;
	}
2840
	preempt_enable();
2841
	return ret;
L
Linus Torvalds 已提交
2842 2843
}

2844 2845 2846 2847
int lookup_module_symbol_name(unsigned long addr, char *symname)
{
	struct module *mod;

2848
	preempt_disable();
2849
	list_for_each_entry_rcu(mod, &modules, list) {
2850 2851
		if (within_module_init(addr, mod) ||
		    within_module_core(addr, mod)) {
2852 2853 2854 2855 2856
			const char *sym;

			sym = get_ksymbol(mod, addr, NULL, NULL);
			if (!sym)
				goto out;
2857
			strlcpy(symname, sym, KSYM_NAME_LEN);
2858
			preempt_enable();
2859 2860 2861 2862
			return 0;
		}
	}
out:
2863
	preempt_enable();
2864 2865 2866
	return -ERANGE;
}

2867 2868 2869 2870 2871
int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
			unsigned long *offset, char *modname, char *name)
{
	struct module *mod;

2872
	preempt_disable();
2873
	list_for_each_entry_rcu(mod, &modules, list) {
2874 2875
		if (within_module_init(addr, mod) ||
		    within_module_core(addr, mod)) {
2876 2877 2878 2879 2880 2881
			const char *sym;

			sym = get_ksymbol(mod, addr, size, offset);
			if (!sym)
				goto out;
			if (modname)
2882
				strlcpy(modname, mod->name, MODULE_NAME_LEN);
2883
			if (name)
2884
				strlcpy(name, sym, KSYM_NAME_LEN);
2885
			preempt_enable();
2886 2887 2888 2889
			return 0;
		}
	}
out:
2890
	preempt_enable();
2891 2892 2893
	return -ERANGE;
}

2894 2895
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
2896 2897 2898
{
	struct module *mod;

2899
	preempt_disable();
2900
	list_for_each_entry_rcu(mod, &modules, list) {
L
Linus Torvalds 已提交
2901 2902 2903
		if (symnum < mod->num_symtab) {
			*value = mod->symtab[symnum].st_value;
			*type = mod->symtab[symnum].st_info;
2904
			strlcpy(name, mod->strtab + mod->symtab[symnum].st_name,
2905 2906
				KSYM_NAME_LEN);
			strlcpy(module_name, mod->name, MODULE_NAME_LEN);
2907
			*exported = is_exported(name, *value, mod);
2908
			preempt_enable();
2909
			return 0;
L
Linus Torvalds 已提交
2910 2911 2912
		}
		symnum -= mod->num_symtab;
	}
2913
	preempt_enable();
2914
	return -ERANGE;
L
Linus Torvalds 已提交
2915 2916 2917 2918 2919 2920 2921
}

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

	for (i = 0; i < mod->num_symtab; i++)
2922 2923
		if (strcmp(name, mod->strtab+mod->symtab[i].st_name) == 0 &&
		    mod->symtab[i].st_info != 'U')
L
Linus Torvalds 已提交
2924 2925 2926 2927 2928 2929 2930 2931 2932 2933 2934 2935
			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. */
2936
	preempt_disable();
L
Linus Torvalds 已提交
2937 2938 2939 2940 2941 2942
	if ((colon = strchr(name, ':')) != NULL) {
		*colon = '\0';
		if ((mod = find_module(name)) != NULL)
			ret = mod_find_symname(mod, colon+1);
		*colon = ':';
	} else {
2943
		list_for_each_entry_rcu(mod, &modules, list)
L
Linus Torvalds 已提交
2944 2945 2946
			if ((ret = mod_find_symname(mod, name)) != 0)
				break;
	}
2947
	preempt_enable();
L
Linus Torvalds 已提交
2948 2949
	return ret;
}
2950 2951 2952 2953 2954 2955 2956 2957 2958 2959 2960 2961 2962 2963 2964 2965 2966 2967 2968

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) {
		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
2969 2970
#endif /* CONFIG_KALLSYMS */

2971
static char *module_flags(struct module *mod, char *buf)
2972 2973 2974
{
	int bx = 0;

2975 2976 2977
	if (mod->taints ||
	    mod->state == MODULE_STATE_GOING ||
	    mod->state == MODULE_STATE_COMING) {
2978
		buf[bx++] = '(';
A
Andi Kleen 已提交
2979
		if (mod->taints & (1 << TAINT_PROPRIETARY_MODULE))
2980
			buf[bx++] = 'P';
A
Andi Kleen 已提交
2981
		if (mod->taints & (1 << TAINT_FORCED_MODULE))
2982
			buf[bx++] = 'F';
2983
		if (mod->taints & (1 << TAINT_CRAP))
2984
			buf[bx++] = 'C';
2985 2986 2987 2988 2989
		/*
		 * TAINT_FORCED_RMMOD: could be added.
		 * TAINT_UNSAFE_SMP, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't
		 * apply to modules.
		 */
2990 2991 2992 2993 2994 2995 2996

		/* 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++] = '+';
2997 2998 2999 3000 3001 3002 3003
		buf[bx++] = ')';
	}
	buf[bx] = '\0';

	return buf;
}

3004 3005 3006 3007 3008 3009 3010 3011 3012 3013 3014 3015 3016 3017 3018 3019 3020 3021
#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
3022 3023 3024
static int m_show(struct seq_file *m, void *p)
{
	struct module *mod = list_entry(p, struct module, list);
3025 3026
	char buf[8];

3027
	seq_printf(m, "%s %u",
L
Linus Torvalds 已提交
3028 3029 3030 3031 3032 3033 3034 3035 3036 3037 3038
		   mod->name, mod->init_size + mod->core_size);
	print_unload_info(m, mod);

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

3039 3040
	/* Taints info */
	if (mod->taints)
3041
		seq_printf(m, " %s", module_flags(mod, buf));
3042

L
Linus Torvalds 已提交
3043 3044 3045 3046 3047 3048 3049 3050 3051
	seq_printf(m, "\n");
	return 0;
}

/* Format: modulename size refcount deps address

   Where refcount is a number or -, and deps is a comma-separated list
   of depends or -.
*/
3052
static const struct seq_operations modules_op = {
L
Linus Torvalds 已提交
3053 3054 3055 3056 3057 3058
	.start	= m_start,
	.next	= m_next,
	.stop	= m_stop,
	.show	= m_show
};

3059 3060 3061 3062 3063 3064 3065 3066 3067 3068 3069 3070 3071 3072 3073 3074 3075 3076 3077 3078
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
3079 3080 3081 3082 3083 3084
/* 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
3085
	preempt_disable();
3086
	list_for_each_entry_rcu(mod, &modules, list) {
L
Linus Torvalds 已提交
3087 3088
		if (mod->num_exentries == 0)
			continue;
D
Daniel Walker 已提交
3089

L
Linus Torvalds 已提交
3090 3091 3092 3093 3094 3095
		e = search_extable(mod->extable,
				   mod->extable + mod->num_exentries - 1,
				   addr);
		if (e)
			break;
	}
R
Rusty Russell 已提交
3096
	preempt_enable();
L
Linus Torvalds 已提交
3097 3098

	/* Now, if we found one, we are running inside it now, hence
D
Daniel Walker 已提交
3099
	   we cannot unload the module, hence no refcnt needed. */
L
Linus Torvalds 已提交
3100 3101 3102
	return e;
}

3103
/*
R
Rusty Russell 已提交
3104 3105 3106 3107 3108
 * 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).
3109
 */
R
Rusty Russell 已提交
3110
bool is_module_address(unsigned long addr)
3111
{
R
Rusty Russell 已提交
3112
	bool ret;
3113

R
Rusty Russell 已提交
3114
	preempt_disable();
R
Rusty Russell 已提交
3115
	ret = __module_address(addr) != NULL;
R
Rusty Russell 已提交
3116
	preempt_enable();
3117

R
Rusty Russell 已提交
3118
	return ret;
3119 3120
}

R
Rusty Russell 已提交
3121 3122 3123 3124 3125 3126 3127
/*
 * __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.
 */
3128
struct module *__module_address(unsigned long addr)
L
Linus Torvalds 已提交
3129 3130 3131
{
	struct module *mod;

3132 3133 3134
	if (addr < module_addr_min || addr > module_addr_max)
		return NULL;

3135
	list_for_each_entry_rcu(mod, &modules, list)
R
Rusty Russell 已提交
3136 3137
		if (within_module_core(addr, mod)
		    || within_module_init(addr, mod))
L
Linus Torvalds 已提交
3138 3139 3140
			return mod;
	return NULL;
}
3141
EXPORT_SYMBOL_GPL(__module_address);
L
Linus Torvalds 已提交
3142

R
Rusty Russell 已提交
3143 3144 3145 3146 3147 3148 3149 3150 3151 3152 3153 3154 3155 3156 3157 3158 3159 3160 3161 3162 3163 3164 3165 3166 3167 3168 3169 3170 3171 3172 3173 3174 3175 3176 3177 3178 3179
/*
 * 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;
}
3180
EXPORT_SYMBOL_GPL(__module_text_address);
R
Rusty Russell 已提交
3181

L
Linus Torvalds 已提交
3182 3183 3184 3185
/* Don't grab lock, we're oopsing. */
void print_modules(void)
{
	struct module *mod;
3186
	char buf[8];
L
Linus Torvalds 已提交
3187

3188
	printk(KERN_DEFAULT "Modules linked in:");
3189 3190 3191
	/* Most callers should already have preempt disabled, but make sure */
	preempt_disable();
	list_for_each_entry_rcu(mod, &modules, list)
3192
		printk(" %s%s", mod->name, module_flags(mod, buf));
3193
	preempt_enable();
3194 3195
	if (last_unloaded_module[0])
		printk(" [last unloaded: %s]", last_unloaded_module);
L
Linus Torvalds 已提交
3196 3197 3198 3199
	printk("\n");
}

#ifdef CONFIG_MODVERSIONS
3200 3201 3202 3203 3204 3205 3206 3207 3208 3209
/* 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,
		   struct tracepoint *tp)
{
}
EXPORT_SYMBOL(module_layout);
L
Linus Torvalds 已提交
3210
#endif
M
Mathieu Desnoyers 已提交
3211

M
Mathieu Desnoyers 已提交
3212 3213 3214 3215 3216 3217 3218 3219 3220 3221 3222 3223 3224 3225 3226 3227 3228 3229 3230 3231 3232 3233 3234 3235 3236 3237 3238 3239 3240 3241 3242 3243 3244 3245 3246 3247 3248 3249 3250 3251 3252 3253 3254 3255 3256 3257
#ifdef CONFIG_TRACEPOINTS
void module_update_tracepoints(void)
{
	struct module *mod;

	mutex_lock(&module_mutex);
	list_for_each_entry(mod, &modules, list)
		if (!mod->taints)
			tracepoint_update_probe_range(mod->tracepoints,
				mod->tracepoints + mod->num_tracepoints);
	mutex_unlock(&module_mutex);
}

/*
 * Returns 0 if current not found.
 * Returns 1 if current found.
 */
int module_get_iter_tracepoints(struct tracepoint_iter *iter)
{
	struct module *iter_mod;
	int found = 0;

	mutex_lock(&module_mutex);
	list_for_each_entry(iter_mod, &modules, list) {
		if (!iter_mod->taints) {
			/*
			 * Sorted module list
			 */
			if (iter_mod < iter->module)
				continue;
			else if (iter_mod > iter->module)
				iter->tracepoint = NULL;
			found = tracepoint_get_iter_range(&iter->tracepoint,
				iter_mod->tracepoints,
				iter_mod->tracepoints
					+ iter_mod->num_tracepoints);
			if (found) {
				iter->module = iter_mod;
				break;
			}
		}
	}
	mutex_unlock(&module_mutex);
	return found;
}
#endif