module.c 76.8 KB
Newer Older
1
/*
Linus Torvalds's avatar
Linus Torvalds committed
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>
Linus Torvalds's avatar
Linus Torvalds committed
22
#include <linux/init.h>
23
#include <linux/kallsyms.h>
24
#include <linux/fs.h>
Roland McGrath's avatar
Roland McGrath committed
25
#include <linux/sysfs.h>
26
#include <linux/kernel.h>
Linus Torvalds's avatar
Linus Torvalds committed
27 28 29
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/elf.h>
30
#include <linux/proc_fs.h>
Linus Torvalds's avatar
Linus Torvalds committed
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>
Linus Torvalds's avatar
Linus Torvalds committed
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>
Al Viro's avatar
Al Viro committed
42
#include <linux/sched.h>
Linus Torvalds's avatar
Linus Torvalds committed
43 44
#include <linux/stop_machine.h>
#include <linux/device.h>
45
#include <linux/string.h>
46
#include <linux/mutex.h>
47
#include <linux/rculist.h>
Linus Torvalds's avatar
Linus Torvalds committed
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>
53
#include <linux/tracepoint.h>
54
#include <linux/ftrace.h>
55
#include <linux/async.h>
56
#include <linux/percpu.h>
57
#include <linux/kmemleak.h>
Linus Torvalds's avatar
Linus Torvalds committed
58

59 60 61 62 63
#define CREATE_TRACE_POINTS
#include <trace/events/module.h>

EXPORT_TRACEPOINT_SYMBOL(module_get);

Linus Torvalds's avatar
Linus Torvalds committed
64 65 66 67 68 69 70 71 72 73 74 75 76
#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))

Rusty Russell's avatar
Rusty Russell committed
77
/* List of modules, protected by module_mutex or preempt_disable
78
 * (delete uses stop_machine/add uses RCU list operations). */
79 80
DEFINE_MUTEX(module_mutex);
EXPORT_SYMBOL_GPL(module_mutex);
Linus Torvalds's avatar
Linus Torvalds committed
81 82
static LIST_HEAD(modules);

83 84 85
/* Block module loading/unloading? */
int modules_disabled = 0;

86 87 88
/* Waiting for a module to finish initializing? */
static DECLARE_WAIT_QUEUE_HEAD(module_wq);

89
static BLOCKING_NOTIFIER_HEAD(module_notify_list);
Linus Torvalds's avatar
Linus Torvalds committed
90

Rusty Russell's avatar
Rusty Russell committed
91
/* Bounds of module allocation, for speeding __module_address */
92 93
static unsigned long module_addr_min = -1UL, module_addr_max = 0;

Linus Torvalds's avatar
Linus Torvalds committed
94 95
int register_module_notifier(struct notifier_block * nb)
{
96
	return blocking_notifier_chain_register(&module_notify_list, nb);
Linus Torvalds's avatar
Linus Torvalds committed
97 98 99 100 101
}
EXPORT_SYMBOL(register_module_notifier);

int unregister_module_notifier(struct notifier_block * nb)
{
102
	return blocking_notifier_chain_unregister(&module_notify_list, nb);
Linus Torvalds's avatar
Linus Torvalds committed
103 104 105
}
EXPORT_SYMBOL(unregister_module_notifier);

106 107
/* We require a truly strong try_module_get(): 0 means failure due to
   ongoing or failed initialization etc. */
Linus Torvalds's avatar
Linus Torvalds committed
108 109 110
static inline int strong_try_module_get(struct module *mod)
{
	if (mod && mod->state == MODULE_STATE_COMING)
111 112
		return -EBUSY;
	if (try_module_get(mod))
Linus Torvalds's avatar
Linus Torvalds committed
113
		return 0;
114 115
	else
		return -ENOENT;
Linus Torvalds's avatar
Linus Torvalds committed
116 117
}

118 119 120
static inline void add_taint_module(struct module *mod, unsigned flag)
{
	add_taint(flag);
Andi Kleen's avatar
Andi Kleen committed
121
	mod->taints |= (1U << flag);
122 123
}

124 125 126
/*
 * 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.
Linus Torvalds's avatar
Linus Torvalds committed
127 128 129 130 131 132 133
 */
void __module_put_and_exit(struct module *mod, long code)
{
	module_put(mod);
	do_exit(code);
}
EXPORT_SYMBOL(__module_put_and_exit);
134

Linus Torvalds's avatar
Linus Torvalds committed
135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150
/* 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;
}

151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173
/* 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;
}

Linus Torvalds's avatar
Linus Torvalds committed
174 175 176 177 178
/* 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[];
179 180
extern const struct kernel_symbol __start___ksymtab_gpl_future[];
extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
181 182
extern const struct kernel_symbol __start___ksymtab_gpl_future[];
extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
Linus Torvalds's avatar
Linus Torvalds committed
183 184
extern const unsigned long __start___kcrctab[];
extern const unsigned long __start___kcrctab_gpl[];
185
extern const unsigned long __start___kcrctab_gpl_future[];
186 187 188 189 190
#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[];
191 192
extern const unsigned long __start___kcrctab_unused[];
extern const unsigned long __start___kcrctab_unused_gpl[];
193
#endif
Linus Torvalds's avatar
Linus Torvalds committed
194 195 196 197

#ifndef CONFIG_MODVERSIONS
#define symversion(base, idx) NULL
#else
198
#define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
Linus Torvalds's avatar
Linus Torvalds committed
199 200
#endif

201 202 203 204 205 206 207
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)
208
{
209
	unsigned int i, j;
210

211 212 213 214
	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;
215
	}
216 217

	return false;
218 219
}

220
/* Returns true as soon as fn returns true, otherwise false. */
221 222
bool each_symbol(bool (*fn)(const struct symsearch *arr, struct module *owner,
			    unsigned int symnum, void *data), void *data)
223 224 225 226
{
	struct module *mod;
	const struct symsearch arr[] = {
		{ __start___ksymtab, __stop___ksymtab, __start___kcrctab,
227
		  NOT_GPL_ONLY, false },
228
		{ __start___ksymtab_gpl, __stop___ksymtab_gpl,
229 230
		  __start___kcrctab_gpl,
		  GPL_ONLY, false },
231
		{ __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future,
232 233
		  __start___kcrctab_gpl_future,
		  WILL_BE_GPL_ONLY, false },
234
#ifdef CONFIG_UNUSED_SYMBOLS
235
		{ __start___ksymtab_unused, __stop___ksymtab_unused,
236 237
		  __start___kcrctab_unused,
		  NOT_GPL_ONLY, true },
238
		{ __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl,
239 240
		  __start___kcrctab_unused_gpl,
		  GPL_ONLY, true },
241
#endif
242
	};
243

244 245
	if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data))
		return true;
246

247
	list_for_each_entry_rcu(mod, &modules, list) {
248 249
		struct symsearch arr[] = {
			{ mod->syms, mod->syms + mod->num_syms, mod->crcs,
250
			  NOT_GPL_ONLY, false },
251
			{ mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
252 253
			  mod->gpl_crcs,
			  GPL_ONLY, false },
254 255
			{ mod->gpl_future_syms,
			  mod->gpl_future_syms + mod->num_gpl_future_syms,
256 257
			  mod->gpl_future_crcs,
			  WILL_BE_GPL_ONLY, false },
258
#ifdef CONFIG_UNUSED_SYMBOLS
259 260
			{ mod->unused_syms,
			  mod->unused_syms + mod->num_unused_syms,
261 262
			  mod->unused_crcs,
			  NOT_GPL_ONLY, true },
263 264
			{ mod->unused_gpl_syms,
			  mod->unused_gpl_syms + mod->num_unused_gpl_syms,
265 266
			  mod->unused_gpl_crcs,
			  GPL_ONLY, true },
267
#endif
268 269
		};

270 271 272 273 274
		if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data))
			return true;
	}
	return false;
}
275
EXPORT_SYMBOL_GPL(each_symbol);
276 277 278 279 280 281 282 283 284 285

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

	/* Output */
	struct module *owner;
	const unsigned long *crc;
286
	const struct kernel_symbol *sym;
287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307
};

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");
308
		}
Linus Torvalds's avatar
Linus Torvalds committed
309
	}
310

311
#ifdef CONFIG_UNUSED_SYMBOLS
312 313 314 315 316 317 318 319 320 321 322
	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");
	}
323
#endif
324 325 326

	fsa->owner = owner;
	fsa->crc = symversion(syms->crcs, symnum);
327
	fsa->sym = &syms->start[symnum];
328 329 330
	return true;
}

331 332
/* Find a symbol and return it, along with, (optional) crc and
 * (optional) module which owns it */
333 334 335 336 337
const struct kernel_symbol *find_symbol(const char *name,
					struct module **owner,
					const unsigned long **crc,
					bool gplok,
					bool warn)
338 339 340 341 342 343 344 345 346 347 348 349
{
	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;
350
		return fsa.sym;
351 352
	}

Linus Torvalds's avatar
Linus Torvalds committed
353
	DEBUGP("Failed to find symbol %s\n", name);
354
	return NULL;
Linus Torvalds's avatar
Linus Torvalds committed
355
}
356
EXPORT_SYMBOL_GPL(find_symbol);
Linus Torvalds's avatar
Linus Torvalds committed
357 358

/* Search for module by name: must hold module_mutex. */
359
struct module *find_module(const char *name)
Linus Torvalds's avatar
Linus Torvalds committed
360 361 362 363 364 365 366 367 368
{
	struct module *mod;

	list_for_each_entry(mod, &modules, list) {
		if (strcmp(mod->name, name) == 0)
			return mod;
	}
	return NULL;
}
369
EXPORT_SYMBOL_GPL(find_module);
Linus Torvalds's avatar
Linus Torvalds committed
370 371

#ifdef CONFIG_SMP
372 373 374 375 376 377 378 379 380 381 382 383

static void *percpu_modalloc(unsigned long size, unsigned long align,
			     const char *name)
{
	void *ptr;

	if (align > PAGE_SIZE) {
		printk(KERN_WARNING "%s: per-cpu alignment %li > %li\n",
		       name, align, PAGE_SIZE);
		align = PAGE_SIZE;
	}

384
	ptr = __alloc_reserved_percpu(size, align);
385 386 387 388 389 390 391 392 393 394 395
	if (!ptr)
		printk(KERN_WARNING
		       "Could not allocate %lu bytes percpu data\n", size);
	return ptr;
}

static void percpu_modfree(void *freeme)
{
	free_percpu(freeme);
}

396 397 398 399 400 401 402 403 404 405 406 407 408 409 410
static unsigned int find_pcpusec(Elf_Ehdr *hdr,
				 Elf_Shdr *sechdrs,
				 const char *secstrings)
{
	return find_sec(hdr, sechdrs, secstrings, ".data.percpu");
}

static void percpu_modcopy(void *pcpudest, const void *from, unsigned long size)
{
	int cpu;

	for_each_possible_cpu(cpu)
		memcpy(pcpudest + per_cpu_offset(cpu), from, size);
}

Linus Torvalds's avatar
Linus Torvalds committed
411
#else /* ... !CONFIG_SMP */
412

413 414
static inline void *percpu_modalloc(unsigned long size, unsigned long align,
				    const char *name)
Linus Torvalds's avatar
Linus Torvalds committed
415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433
{
	return NULL;
}
static inline void percpu_modfree(void *pcpuptr)
{
	BUG();
}
static inline unsigned int find_pcpusec(Elf_Ehdr *hdr,
					Elf_Shdr *sechdrs,
					const char *secstrings)
{
	return 0;
}
static inline void percpu_modcopy(void *pcpudst, const void *src,
				  unsigned long size)
{
	/* pcpusec should be 0, and size of that section should be 0. */
	BUG_ON(size != 0);
}
434

Linus Torvalds's avatar
Linus Torvalds committed
435 436
#endif /* CONFIG_SMP */

437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452
#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)                  \
{                                                                     \
453 454
	kfree(mod->field);                                            \
	mod->field = NULL;                                            \
455 456
}                                                                     \
static struct module_attribute modinfo_##field = {                    \
457
	.attr = { .name = __stringify(field), .mode = 0444 },         \
458 459 460 461 462 463 464 465 466
	.show = show_modinfo_##field,                                 \
	.setup = setup_modinfo_##field,                               \
	.test = modinfo_##field##_exists,                             \
	.free = free_modinfo_##field,                                 \
};

MODINFO_ATTR(version);
MODINFO_ATTR(srcversion);

467 468
static char last_unloaded_module[MODULE_NAME_LEN+1];

469
#ifdef CONFIG_MODULE_UNLOAD
Linus Torvalds's avatar
Linus Torvalds committed
470 471 472
/* Init the unload section of the module. */
static void module_unload_init(struct module *mod)
{
473
	int cpu;
Linus Torvalds's avatar
Linus Torvalds committed
474 475

	INIT_LIST_HEAD(&mod->modules_which_use_me);
476 477
	for_each_possible_cpu(cpu)
		local_set(__module_ref_addr(mod, cpu), 0);
Linus Torvalds's avatar
Linus Torvalds committed
478
	/* Hold reference count during initialization. */
479
	local_set(__module_ref_addr(mod, raw_smp_processor_id()), 1);
Linus Torvalds's avatar
Linus Torvalds committed
480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506
	/* Backwards compatibility macros put refcount during init. */
	mod->waiter = current;
}

/* modules using other modules */
struct module_use
{
	struct list_head list;
	struct module *module_which_uses;
};

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

	list_for_each_entry(use, &b->modules_which_use_me, list) {
		if (use->module_which_uses == a) {
			DEBUGP("%s uses %s!\n", a->name, b->name);
			return 1;
		}
	}
	DEBUGP("%s does not use %s!\n", a->name, b->name);
	return 0;
}

/* Module a uses b */
507
int use_module(struct module *a, struct module *b)
Linus Torvalds's avatar
Linus Torvalds committed
508 509
{
	struct module_use *use;
510
	int no_warn, err;
Kay Sievers's avatar
Kay Sievers committed
511

Linus Torvalds's avatar
Linus Torvalds committed
512 513
	if (b == NULL || already_uses(a, b)) return 1;

514 515 516 517 518 519 520 521 522 523 524
	/* If we're interrupted or time out, we fail. */
	if (wait_event_interruptible_timeout(
		    module_wq, (err = strong_try_module_get(b)) != -EBUSY,
		    30 * HZ) <= 0) {
		printk("%s: gave up waiting for init of module %s.\n",
		       a->name, b->name);
		return 0;
	}

	/* If strong_try_module_get() returned a different error, we fail. */
	if (err)
Linus Torvalds's avatar
Linus Torvalds committed
525 526 527 528 529 530 531 532 533 534 535 536
		return 0;

	DEBUGP("Allocating new usage for %s.\n", a->name);
	use = kmalloc(sizeof(*use), GFP_ATOMIC);
	if (!use) {
		printk("%s: out of memory loading\n", a->name);
		module_put(b);
		return 0;
	}

	use->module_which_uses = a;
	list_add(&use->list, &b->modules_which_use_me);
Kay Sievers's avatar
Kay Sievers committed
537
	no_warn = sysfs_create_link(b->holders_dir, &a->mkobj.kobj, a->name);
Linus Torvalds's avatar
Linus Torvalds committed
538 539
	return 1;
}
540
EXPORT_SYMBOL_GPL(use_module);
Linus Torvalds's avatar
Linus Torvalds committed
541 542 543 544 545 546 547 548 549 550 551 552 553 554 555

/* Clear the unload stuff of the module. */
static void module_unload_free(struct module *mod)
{
	struct module *i;

	list_for_each_entry(i, &modules, list) {
		struct module_use *use;

		list_for_each_entry(use, &i->modules_which_use_me, list) {
			if (use->module_which_uses == mod) {
				DEBUGP("%s unusing %s\n", mod->name, i->name);
				module_put(i);
				list_del(&use->list);
				kfree(use);
Kay Sievers's avatar
Kay Sievers committed
556
				sysfs_remove_link(i->holders_dir, mod->name);
Linus Torvalds's avatar
Linus Torvalds committed
557 558 559 560 561 562 563 564
				/* There can be at most one match. */
				break;
			}
		}
	}
}

#ifdef CONFIG_MODULE_FORCE_UNLOAD
565
static inline int try_force_unload(unsigned int flags)
Linus Torvalds's avatar
Linus Torvalds committed
566 567 568
{
	int ret = (flags & O_TRUNC);
	if (ret)
569
		add_taint(TAINT_FORCED_RMMOD);
Linus Torvalds's avatar
Linus Torvalds committed
570 571 572
	return ret;
}
#else
573
static inline int try_force_unload(unsigned int flags)
Linus Torvalds's avatar
Linus Torvalds committed
574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590
{
	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;

591 592
	/* If it's not unused, quit unless we're forcing. */
	if (module_refcount(sref->mod) != 0) {
593
		if (!(*sref->forced = try_force_unload(sref->flags)))
Linus Torvalds's avatar
Linus Torvalds committed
594 595 596 597 598 599 600 601 602 603
			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)
{
604 605
	if (flags & O_NONBLOCK) {
		struct stopref sref = { mod, flags, forced };
Linus Torvalds's avatar
Linus Torvalds committed
606

607
		return stop_machine(__try_stop_module, &sref, NULL);
608 609 610 611 612 613
	} else {
		/* We don't need to stop the machine for this. */
		mod->state = MODULE_STATE_GOING;
		synchronize_sched();
		return 0;
	}
Linus Torvalds's avatar
Linus Torvalds committed
614 615 616 617
}

unsigned int module_refcount(struct module *mod)
{
618 619
	unsigned int total = 0;
	int cpu;
Linus Torvalds's avatar
Linus Torvalds committed
620

621 622
	for_each_possible_cpu(cpu)
		total += local_read(__module_ref_addr(mod, cpu));
Linus Torvalds's avatar
Linus Torvalds committed
623 624 625 626 627 628 629 630 631
	return total;
}
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)
{
632
	/* Since we might sleep for some time, release the mutex first */
633
	mutex_unlock(&module_mutex);
Linus Torvalds's avatar
Linus Torvalds committed
634 635 636 637 638 639 640 641
	for (;;) {
		DEBUGP("Looking at refcount...\n");
		set_current_state(TASK_UNINTERRUPTIBLE);
		if (module_refcount(mod) == 0)
			break;
		schedule();
	}
	current->state = TASK_RUNNING;
642
	mutex_lock(&module_mutex);
Linus Torvalds's avatar
Linus Torvalds committed
643 644
}

645 646
SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
		unsigned int, flags)
Linus Torvalds's avatar
Linus Torvalds committed
647 648
{
	struct module *mod;
649
	char name[MODULE_NAME_LEN];
Linus Torvalds's avatar
Linus Torvalds committed
650 651
	int ret, forced = 0;

652
	if (!capable(CAP_SYS_MODULE) || modules_disabled)
653 654 655 656 657 658
		return -EPERM;

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

659 660 661 662 663 664 665 666 667 668
	/* Create stop_machine threads since free_module relies on
	 * a non-failing stop_machine call. */
	ret = stop_machine_create();
	if (ret)
		return ret;

	if (mutex_lock_interruptible(&module_mutex) != 0) {
		ret = -EINTR;
		goto out_stop;
	}
Linus Torvalds's avatar
Linus Torvalds committed
669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691

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

	if (!list_empty(&mod->modules_which_use_me)) {
		/* 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 */
692
	if (mod->init && !mod->exit) {
693
		forced = try_force_unload(flags);
Linus Torvalds's avatar
Linus Torvalds committed
694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712
		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);

713
	mutex_unlock(&module_mutex);
Linus Torvalds's avatar
Linus Torvalds committed
714
	/* Final destruction now noone is using it. */
715
	if (mod->exit != NULL)
Linus Torvalds's avatar
Linus Torvalds committed
716
		mod->exit();
717 718
	blocking_notifier_call_chain(&module_notify_list,
				     MODULE_STATE_GOING, mod);
719
	async_synchronize_full();
720
	mutex_lock(&module_mutex);
721
	/* Store the name of the last unloaded module for diagnostic purposes */
722
	strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
723
	ddebug_remove_module(mod->name);
Linus Torvalds's avatar
Linus Torvalds committed
724 725 726
	free_module(mod);

 out:
727
	mutex_unlock(&module_mutex);
728 729
out_stop:
	stop_machine_destroy();
Linus Torvalds's avatar
Linus Torvalds committed
730 731 732
	return ret;
}

733
static inline void print_unload_info(struct seq_file *m, struct module *mod)
Linus Torvalds's avatar
Linus Torvalds committed
734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759
{
	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. */
	list_for_each_entry(use, &mod->modules_which_use_me, list) {
		printed_something = 1;
		seq_printf(m, "%s,", use->module_which_uses->name);
	}

	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;

Rusty Russell's avatar
Rusty Russell committed
760
	preempt_disable();
761
	if (!find_symbol(symbol, &owner, NULL, true, false))
Linus Torvalds's avatar
Linus Torvalds committed
762 763
		BUG();
	module_put(owner);
Rusty Russell's avatar
Rusty Russell committed
764
	preempt_enable();
Linus Torvalds's avatar
Linus Torvalds committed
765 766 767
}
EXPORT_SYMBOL(__symbol_put);

768
/* Note this assumes addr is a function, which it currently always is. */
Linus Torvalds's avatar
Linus Torvalds committed
769 770
void symbol_put_addr(void *addr)
{
771
	struct module *modaddr;
772
	unsigned long a = (unsigned long)dereference_function_descriptor(addr);
Linus Torvalds's avatar
Linus Torvalds committed
773

774
	if (core_kernel_text(a))
775
		return;
Linus Torvalds's avatar
Linus Torvalds committed
776

777 778
	/* module_text_address is safe here: we're supposed to have reference
	 * to module from symbol_get, so it can't go away. */
779
	modaddr = __module_text_address(a);
780
	BUG_ON(!modaddr);
781
	module_put(modaddr);
Linus Torvalds's avatar
Linus Torvalds committed
782 783 784 785 786 787
}
EXPORT_SYMBOL_GPL(symbol_put_addr);

static ssize_t show_refcnt(struct module_attribute *mattr,
			   struct module *mod, char *buffer)
{
788
	return sprintf(buffer, "%u\n", module_refcount(mod));
Linus Torvalds's avatar
Linus Torvalds committed
789 790 791
}

static struct module_attribute refcnt = {
792
	.attr = { .name = "refcnt", .mode = 0444 },
Linus Torvalds's avatar
Linus Torvalds committed
793 794 795
	.show = show_refcnt,
};

Al Viro's avatar
Al Viro committed
796 797 798 799
void module_put(struct module *module)
{
	if (module) {
		unsigned int cpu = get_cpu();
800
		local_dec(__module_ref_addr(module, cpu));
801 802
		trace_module_put(module, _RET_IP_,
				 local_read(__module_ref_addr(module, cpu)));
Al Viro's avatar
Al Viro committed
803 804 805 806 807 808 809 810
		/* Maybe they're waiting for us to drop reference? */
		if (unlikely(!module_is_live(module)))
			wake_up_process(module->waiter);
		put_cpu();
	}
}
EXPORT_SYMBOL(module_put);

Linus Torvalds's avatar
Linus Torvalds committed
811
#else /* !CONFIG_MODULE_UNLOAD */
812
static inline void print_unload_info(struct seq_file *m, struct module *mod)
Linus Torvalds's avatar
Linus Torvalds committed
813 814 815 816 817 818 819 820 821
{
	/* We don't know the usage count, or what modules are using. */
	seq_printf(m, " - -");
}

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

822
int use_module(struct module *a, struct module *b)
Linus Torvalds's avatar
Linus Torvalds committed
823
{
824
	return strong_try_module_get(b) == 0;
Linus Torvalds's avatar
Linus Torvalds committed
825
}
826
EXPORT_SYMBOL_GPL(use_module);
Linus Torvalds's avatar
Linus Torvalds committed
827 828 829 830 831 832

static inline void module_unload_init(struct module *mod)
{
}
#endif /* CONFIG_MODULE_UNLOAD */

833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852
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 = {
853
	.attr = { .name = "initstate", .mode = 0444 },
854 855 856
	.show = show_initstate,
};

857 858 859
static struct module_attribute *modinfo_attrs[] = {
	&modinfo_version,
	&modinfo_srcversion,
860
	&initstate,
861 862 863 864 865 866
#ifdef CONFIG_MODULE_UNLOAD
	&refcnt,
#endif
	NULL,
};

Linus Torvalds's avatar
Linus Torvalds committed
867 868
static const char vermagic[] = VERMAGIC_STRING;

869
static int try_to_force_load(struct module *mod, const char *reason)
870 871
{
#ifdef CONFIG_MODULE_FORCE_LOAD
Andi Kleen's avatar
Andi Kleen committed
872
	if (!test_taint(TAINT_FORCED_MODULE))
873 874
		printk(KERN_WARNING "%s: %s: kernel tainted.\n",
		       mod->name, reason);
875 876 877 878 879 880 881
	add_taint_module(mod, TAINT_FORCED_MODULE);
	return 0;
#else
	return -ENOEXEC;
#endif
}

Linus Torvalds's avatar
Linus Torvalds committed
882 883 884 885 886 887 888 889 890 891 892 893 894 895
#ifdef CONFIG_MODVERSIONS
static int check_version(Elf_Shdr *sechdrs,
			 unsigned int versindex,
			 const char *symname,
			 struct module *mod, 
			 const unsigned long *crc)
{
	unsigned int i, num_versions;
	struct modversion_info *versions;

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

896 897 898 899
	/* No versions at all?  modprobe --force does this. */
	if (versindex == 0)
		return try_to_force_load(mod, symname) == 0;

Linus Torvalds's avatar
Linus Torvalds committed
900 901 902 903 904 905 906 907 908 909 910 911
	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;

		if (versions[i].crc == *crc)
			return 1;
		DEBUGP("Found checksum %lX vs module %lX\n",
		       *crc, versions[i].crc);
912
		goto bad_version;
Linus Torvalds's avatar
Linus Torvalds committed
913
	}
914

915 916 917
	printk(KERN_WARNING "%s: no symbol version for %s\n",
	       mod->name, symname);
	return 0;
918 919 920 921 922

bad_version:
	printk("%s: disagrees about version of symbol %s\n",
	       mod->name, symname);
	return 0;
Linus Torvalds's avatar
Linus Torvalds committed
923 924 925 926 927 928 929 930
}

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

931 932
	if (!find_symbol(MODULE_SYMBOL_PREFIX "module_layout", NULL,
			 &crc, true, false))
Linus Torvalds's avatar
Linus Torvalds committed
933
		BUG();
934
	return check_version(sechdrs, versindex, "module_layout", mod, crc);
Linus Torvalds's avatar
Linus Torvalds committed
935 936
}

937 938 939
/* 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)
Linus Torvalds's avatar
Linus Torvalds committed
940
{
941 942 943 944
	if (has_crcs) {
		amagic += strcspn(amagic, " ");
		bmagic += strcspn(bmagic, " ");
	}
Linus Torvalds's avatar
Linus Torvalds committed
945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963
	return strcmp(amagic, bmagic) == 0;
}
#else
static inline int check_version(Elf_Shdr *sechdrs,
				unsigned int versindex,
				const char *symname,
				struct module *mod, 
				const unsigned long *crc)
{
	return 1;
}

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

964 965
static inline int same_magic(const char *amagic, const char *bmagic,
			     bool has_crcs)
Linus Torvalds's avatar
Linus Torvalds committed
966 967 968 969 970 971 972
{
	return strcmp(amagic, bmagic) == 0;
}
#endif /* CONFIG_MODVERSIONS */

/* Resolve a symbol for this module.  I.e. if we find one, record usage.
   Must be holding module_mutex. */
973 974 975 976
static const struct kernel_symbol *resolve_symbol(Elf_Shdr *sechdrs,
						  unsigned int versindex,
						  const char *name,
						  struct module *mod)
Linus Torvalds's avatar
Linus Torvalds committed
977 978
{
	struct module *owner;
979
	const struct kernel_symbol *sym;
Linus Torvalds's avatar
Linus Torvalds committed
980 981
	const unsigned long *crc;

982
	sym = find_symbol(name, &owner, &crc,
Andi Kleen's avatar
Andi Kleen committed
983
			  !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
984 985 986
	/* use_module can fail due to OOM,
	   or module initialization or unloading */
	if (sym) {
Linus Torvalds's avatar
Linus Torvalds committed
987 988
		if (!check_version(sechdrs, versindex, name, mod, crc) ||
		    !use_module(mod, owner))
989
			sym = NULL;
Linus Torvalds's avatar
Linus Torvalds committed
990
	}
991
	return sym;
Linus Torvalds's avatar
Linus Torvalds committed
992 993 994 995 996 997
}

/*
 * /sys/module/foo/sections stuff
 * J. Corbet <corbet@lwn.net>
 */
998
#if defined(CONFIG_KALLSYMS) && defined(CONFIG_SYSFS)
999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012
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];
};

Linus Torvalds's avatar
Linus Torvalds committed
1013 1014 1015 1016 1017 1018 1019 1020
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);
}

1021 1022
static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
{
1023
	unsigned int section;
1024 1025 1026 1027 1028 1029

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

Linus Torvalds's avatar
Linus Torvalds committed
1030 1031 1032 1033 1034 1035 1036
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;
1037

Linus Torvalds's avatar
Linus Torvalds committed
1038 1039
	/* Count loaded sections and allocate structures */
	for (i = 0; i < nsect; i++)
1040 1041
		if (sechdrs[i].sh_flags & SHF_ALLOC
		    && sechdrs[i].sh_size)
Linus Torvalds's avatar
Linus Torvalds committed
1042 1043 1044 1045 1046
			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]);
1047 1048
	sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
	if (sect_attrs == NULL)
Linus Torvalds's avatar
Linus Torvalds committed
1049 1050 1051 1052 1053 1054
		return;

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

1055
	sect_attrs->nsections = 0;
Linus Torvalds's avatar
Linus Torvalds committed
1056 1057 1058 1059 1060
	sattr = &sect_attrs->attrs[0];
	gattr = &sect_attrs->grp.attrs[0];
	for (i = 0; i < nsect; i++) {
		if (! (sechdrs[i].sh_flags & SHF_ALLOC))
			continue;
1061 1062
		if (!sechdrs[i].sh_size)
			continue;
Linus Torvalds's avatar
Linus Torvalds committed
1063
		sattr->address = sechdrs[i].sh_addr;
1064 1065 1066 1067 1068
		sattr->name = kstrdup(secstrings + sechdrs[i].sh_name,
					GFP_KERNEL);
		if (sattr->name == NULL)
			goto out;
		sect_attrs->nsections++;
Linus Torvalds's avatar
Linus Torvalds committed
1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082
		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:
1083
	free_sect_attrs(sect_attrs);
Linus Torvalds's avatar
Linus Torvalds committed
1084 1085 1086 1087 1088 1089 1090 1091 1092
}

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. */
1093
		free_sect_attrs(mod->sect_attrs);
Linus Torvalds's avatar
Linus Torvalds committed
1094 1095 1096 1097
		mod->sect_attrs = NULL;
	}
}

Roland McGrath's avatar
Roland McGrath committed
1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125
/*
 * /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];
};

static ssize_t module_notes_read(struct kobject *kobj,
				 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]);
1126
		kobject_put(notes_attrs->dir);
Roland McGrath's avatar
Roland McGrath committed
1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137
	}
	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;

1138 1139 1140 1141
	/* failed to create section attributes, so can't create notes */
	if (!mod->sect_attrs)
		return;

Roland McGrath's avatar
Roland McGrath committed
1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173
	/* Count notes sections and allocate structures.  */
	notes = 0;
	for (i = 0; i < nsect; i++)
		if ((sechdrs[i].sh_flags & SHF_ALLOC) &&
		    (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) {
		if (!(sechdrs[i].sh_flags & SHF_ALLOC))
			continue;
		if (sechdrs[i].sh_type == SHT_NOTE) {
			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;
	}

1174
	notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
Roland McGrath's avatar
Roland McGrath committed
1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195
	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);
}

Linus Torvalds's avatar
Linus Torvalds committed
1196
#else
1197

Linus Torvalds's avatar
Linus Torvalds committed
1198 1199 1200 1201 1202 1203 1204 1205
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)
{
}
Roland McGrath's avatar
Roland McGrath committed
1206 1207 1208 1209 1210 1211 1212 1213 1214

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)
{
}
1215
#endif
Linus Torvalds's avatar
Linus Torvalds committed
1216

1217 1218
#ifdef CONFIG_SYSFS
int module_add_modinfo_attrs(struct module *mod)
1219 1220
{
	struct module_attribute *attr;
1221
	struct module_attribute *temp_attr;
1222 1223 1224
	int error = 0;
	int i;

1225 1226 1227 1228 1229 1230 1231
	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;
1232 1233
	for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
		if (!attr->test ||
1234 1235 1236 1237 1238
		    (attr->test && attr->test(mod))) {
			memcpy(temp_attr, attr, sizeof(*temp_attr));
			error = sysfs_create_file(&mod->mkobj.kobj,&temp_attr->attr);
			++temp_attr;
		}
1239 1240 1241 1242
	}
	return error;
}

1243
void module_remove_modinfo_attrs(struct module *mod)
1244 1245 1246 1247
{
	struct module_attribute *attr;
	int i;

1248 1249 1250 1251
	for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
		/* pick a field to test for end of list */
		if (!attr->attr.name)
			break;
1252
		sysfs_remove_file(&mod->mkobj.kobj,&attr->attr);
1253 1254
		if (attr->free)
			attr->free(mod);
1255
	}
1256
	kfree(mod->modinfo_attrs);
1257
}
Linus Torvalds's avatar
Linus Torvalds committed
1258

1259
int mod_sysfs_init(struct module *mod)
Linus Torvalds's avatar
Linus Torvalds committed
1260 1261
{
	int err;
1262
	struct kobject *kobj;
Linus Torvalds's avatar
Linus Torvalds committed
1263

1264 1265
	if (!module_sysfs_initialized) {
		printk(KERN_ERR "%s: module sysfs not initialized\n",
1266 1267 1268 1269
		       mod->name);
		err = -EINVAL;
		goto out;
	}
1270 1271 1272 1273 1274 1275 1276 1277 1278

	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;
	}

Linus Torvalds's avatar
Linus Torvalds committed
1279
	mod->mkobj.mod = mod;
1280

1281 1282 1283 1284 1285 1286
	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);
Kay Sievers's avatar
Kay Sievers committed
1287

1288
	/* delay uevent until full sysfs population */
Kay Sievers's avatar
Kay Sievers committed
1289 1290 1291 1292
out:
	return err;
}

1293
int mod_sysfs_setup(struct module *mod,
Kay Sievers's avatar
Kay Sievers committed
1294 1295 1296 1297 1298
			   struct kernel_param *kparam,
			   unsigned int num_params)
{
	int err;

1299
	mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1300 1301
	if (!mod->holders_dir) {
		err = -ENOMEM;
Kay Sievers's avatar
Kay Sievers committed
1302
		goto out_unreg;
1303
	}
Kay Sievers's avatar
Kay Sievers committed
1304

Linus Torvalds's avatar
Linus Torvalds committed
1305 1306
	err = module_param_sysfs_setup(mod, kparam, num_params);
	if (err)
Kay Sievers's avatar
Kay Sievers committed
1307
		goto out_unreg_holders;
Linus Torvalds's avatar
Linus Torvalds committed
1308

1309 1310
	err = module_add_modinfo_attrs(mod);
	if (err)
1311
		goto out_unreg_param;
1312

1313
	kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
Linus Torvalds's avatar
Linus Torvalds committed
1314 1315
	return 0;

1316 1317
out_unreg_param:
	module_param_sysfs_remove(mod);
Kay Sievers's avatar
Kay Sievers committed
1318
out_unreg_holders:
1319
	kobject_put(mod->holders_dir);
Kay Sievers's avatar
Kay Sievers committed
1320
out_unreg:
1321
	kobject_put(&mod->mkobj.kobj);
Linus Torvalds's avatar
Linus Torvalds committed
1322 1323
	return err;
}
1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336

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

#else /* CONFIG_SYSFS */

static void mod_sysfs_fini(struct module *mod)
{
}

#endif /* CONFIG_SYSFS */
Linus Torvalds's avatar
Linus Torvalds committed
1337 1338 1339

static void mod_kobject_remove(struct module *mod)
{
1340
	module_remove_modinfo_attrs(mod);
Linus Torvalds's avatar
Linus Torvalds committed
1341
	module_param_sysfs_remove(mod);
1342 1343
	kobject_put(mod->mkobj.drivers_dir);
	kobject_put(mod->holders_dir);
1344
	mod_sysfs_fini(mod);
Linus Torvalds's avatar
Linus Torvalds committed
1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357
}

/*
 * 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;
}

1358
/* Free a module, remove from lists, etc (must hold module_mutex). */
Linus Torvalds's avatar
Linus Torvalds committed
1359 1360
static void free_module(struct module *mod)
{
1361 1362
	trace_module_free(mod);

Linus Torvalds's avatar
Linus Torvalds committed
1363
	/* Delete from various lists */
1364
	stop_machine(__unlink_module, mod, NULL);
Roland McGrath's avatar
Roland McGrath committed
1365
	remove_notes_attrs(mod);
Linus Torvalds's avatar
Linus Torvalds committed
1366 1367 1368 1369 1370 1371 1372 1373 1374
	remove_sect_attrs(mod);
	mod_kobject_remove(mod);

	/* Arch-specific cleanup. */
	module_arch_cleanup(mod);

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

1375 1376 1377
	/* Free any allocated parameters. */
	destroy_params(mod->kp, mod->num_kp);

Linus Torvalds's avatar
Linus Torvalds committed
1378 1379 1380 1381 1382
	/* This may be NULL, but that's OK */
	module_free(mod, mod->module_init);
	kfree(mod->args);
	if (mod->percpu)
		percpu_modfree(mod->percpu);
1383 1384 1385 1386
#if defined(CONFIG_MODULE_UNLOAD) && defined(CONFIG_SMP)
	if (mod->refptr)
		percpu_modfree(mod->refptr);
#endif
Ingo Molnar's avatar
Ingo Molnar committed
1387 1388 1389
	/* Free lock-classes: */
	lockdep_free_key_range(mod->module_core, mod->core_size);

Linus Torvalds's avatar
Linus Torvalds committed
1390 1391
	/* Finally, free the core (containing the module structure) */
	module_free(mod, mod->module_core);
1392 1393 1394 1395

#ifdef CONFIG_MPU
	update_protections(current->mm);
#endif
Linus Torvalds's avatar
Linus Torvalds committed
1396 1397 1398 1399 1400
}

void *__symbol_get(const char *symbol)
{
	struct module *owner;
1401
	const struct kernel_symbol *sym;
Linus Torvalds's avatar
Linus Torvalds committed
1402

Rusty Russell's avatar
Rusty Russell committed
1403
	preempt_disable();
1404 1405 1406
	sym = find_symbol(symbol, &owner, NULL, true, true);
	if (sym && strong_try_module_get(owner))
		sym = NULL;
Rusty Russell's avatar
Rusty Russell committed
1407
	preempt_enable();
Linus Torvalds's avatar
Linus Torvalds committed
1408

1409
	return sym ? (void *)sym->value : NULL;
Linus Torvalds's avatar
Linus Torvalds committed
1410 1411 1412
}
EXPORT_SYMBOL_GPL(__symbol_get);

1413 1414
/*
 * Ensure that an exported symbol [global namespace] does not already exist
1415
 * in the kernel or in some other module's exported symbol table.
1416 1417 1418
 */
static int verify_export_symbols(struct module *mod)
{
1419
	unsigned int i;
1420
	struct module *owner;
1421 1422 1423 1424 1425 1426 1427 1428
	const struct kernel_symbol *s;
	struct {
		const struct kernel_symbol *sym;
		unsigned int num;
	} arr[] = {
		{ mod