module.c 58.6 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 21
   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>
#include <linux/init.h>
22
#include <linux/kernel.h>
L
Linus Torvalds 已提交
23 24 25 26 27 28 29
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/elf.h>
#include <linux/seq_file.h>
#include <linux/syscalls.h>
#include <linux/fcntl.h>
#include <linux/rcupdate.h>
30
#include <linux/capability.h>
L
Linus Torvalds 已提交
31 32 33 34 35 36 37 38
#include <linux/cpu.h>
#include <linux/moduleparam.h>
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/vermagic.h>
#include <linux/notifier.h>
#include <linux/stop_machine.h>
#include <linux/device.h>
39
#include <linux/string.h>
40
#include <linux/sched.h>
A
Arjan van de Ven 已提交
41
#include <linux/mutex.h>
42
#include <linux/unwind.h>
L
Linus Torvalds 已提交
43 44 45
#include <asm/uaccess.h>
#include <asm/semaphore.h>
#include <asm/cacheflush.h>
46
#include <linux/license.h>
L
Linus Torvalds 已提交
47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64

#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))

/* Protects module list */
static DEFINE_SPINLOCK(modlist_lock);

/* List of modules, protected by module_mutex AND modlist_lock */
65
static DEFINE_MUTEX(module_mutex);
L
Linus Torvalds 已提交
66 67
static LIST_HEAD(modules);

68
static BLOCKING_NOTIFIER_HEAD(module_notify_list);
L
Linus Torvalds 已提交
69 70 71

int register_module_notifier(struct notifier_block * nb)
{
72
	return blocking_notifier_chain_register(&module_notify_list, nb);
L
Linus Torvalds 已提交
73 74 75 76 77
}
EXPORT_SYMBOL(register_module_notifier);

int unregister_module_notifier(struct notifier_block * nb)
{
78
	return blocking_notifier_chain_unregister(&module_notify_list, nb);
L
Linus Torvalds 已提交
79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121
}
EXPORT_SYMBOL(unregister_module_notifier);

/* We require a truly strong try_module_get() */
static inline int strong_try_module_get(struct module *mod)
{
	if (mod && mod->state == MODULE_STATE_COMING)
		return 0;
	return try_module_get(mod);
}

/* A thread that wants to hold a reference to a module only while it
 * is running can call ths to safely exit.
 * nfsd and lockd use this.
 */
void __module_put_and_exit(struct module *mod, long code)
{
	module_put(mod);
	do_exit(code);
}
EXPORT_SYMBOL(__module_put_and_exit);
	
/* 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;
}

/* 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[];
122 123
extern const struct kernel_symbol __start___ksymtab_gpl_future[];
extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
124 125 126 127 128 129
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[];
extern const struct kernel_symbol __start___ksymtab_gpl_future[];
extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
L
Linus Torvalds 已提交
130 131
extern const unsigned long __start___kcrctab[];
extern const unsigned long __start___kcrctab_gpl[];
132
extern const unsigned long __start___kcrctab_gpl_future[];
133 134
extern const unsigned long __start___kcrctab_unused[];
extern const unsigned long __start___kcrctab_unused_gpl[];
L
Linus Torvalds 已提交
135 136 137 138

#ifndef CONFIG_MODVERSIONS
#define symversion(base, idx) NULL
#else
A
Andrew Morton 已提交
139
#define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
L
Linus Torvalds 已提交
140 141
#endif

142 143 144 145 146 147 148 149 150 151 152 153
/* 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;
}

154 155 156 157 158 159 160 161 162 163 164
static void printk_unused_warning(const char *name)
{
	printk(KERN_WARNING "Symbol %s is marked as UNUSED, "
		"however this module is using it.\n", 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");
}

L
Linus Torvalds 已提交
165 166 167 168 169 170 171
/* Find a symbol, return value, crc and module which owns it */
static unsigned long __find_symbol(const char *name,
				   struct module **owner,
				   const unsigned long **crc,
				   int gplok)
{
	struct module *mod;
172
	const struct kernel_symbol *ks;
L
Linus Torvalds 已提交
173 174 175

	/* Core kernel first. */ 
	*owner = NULL;
176 177 178 179
	ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
	if (ks) {
		*crc = symversion(__start___kcrctab, (ks - __start___ksymtab));
		return ks->value;
L
Linus Torvalds 已提交
180 181
	}
	if (gplok) {
182 183 184 185 186 187 188
		ks = lookup_symbol(name, __start___ksymtab_gpl,
					 __stop___ksymtab_gpl);
		if (ks) {
			*crc = symversion(__start___kcrctab_gpl,
					  (ks - __start___ksymtab_gpl));
			return ks->value;
		}
L
Linus Torvalds 已提交
189
	}
190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205
	ks = lookup_symbol(name, __start___ksymtab_gpl_future,
				 __stop___ksymtab_gpl_future);
	if (ks) {
		if (!gplok) {
			printk(KERN_WARNING "Symbol %s is being used "
			       "by a non-GPL module, which will not "
			       "be allowed in the future\n", name);
			printk(KERN_WARNING "Please see the file "
			       "Documentation/feature-removal-schedule.txt "
			       "in the kernel source tree for more "
			       "details.\n");
		}
		*crc = symversion(__start___kcrctab_gpl_future,
				  (ks - __start___ksymtab_gpl_future));
		return ks->value;
	}
L
Linus Torvalds 已提交
206

207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225
	ks = lookup_symbol(name, __start___ksymtab_unused,
				 __stop___ksymtab_unused);
	if (ks) {
		printk_unused_warning(name);
		*crc = symversion(__start___kcrctab_unused,
				  (ks - __start___ksymtab_unused));
		return ks->value;
	}

	if (gplok)
		ks = lookup_symbol(name, __start___ksymtab_unused_gpl,
				 __stop___ksymtab_unused_gpl);
	if (ks) {
		printk_unused_warning(name);
		*crc = symversion(__start___kcrctab_unused_gpl,
				  (ks - __start___ksymtab_unused_gpl));
		return ks->value;
	}

L
Linus Torvalds 已提交
226 227 228
	/* Now try modules. */ 
	list_for_each_entry(mod, &modules, list) {
		*owner = mod;
229 230 231 232 233
		ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
		if (ks) {
			*crc = symversion(mod->crcs, (ks - mod->syms));
			return ks->value;
		}
L
Linus Torvalds 已提交
234 235

		if (gplok) {
236 237 238 239 240 241
			ks = lookup_symbol(name, mod->gpl_syms,
					   mod->gpl_syms + mod->num_gpl_syms);
			if (ks) {
				*crc = symversion(mod->gpl_crcs,
						  (ks - mod->gpl_syms));
				return ks->value;
L
Linus Torvalds 已提交
242 243
			}
		}
244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260
		ks = lookup_symbol(name, mod->unused_syms, mod->unused_syms + mod->num_unused_syms);
		if (ks) {
			printk_unused_warning(name);
			*crc = symversion(mod->unused_crcs, (ks - mod->unused_syms));
			return ks->value;
		}

		if (gplok) {
			ks = lookup_symbol(name, mod->unused_gpl_syms,
					   mod->unused_gpl_syms + mod->num_unused_gpl_syms);
			if (ks) {
				printk_unused_warning(name);
				*crc = symversion(mod->unused_gpl_crcs,
						  (ks - mod->unused_gpl_syms));
				return ks->value;
			}
		}
261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277
		ks = lookup_symbol(name, mod->gpl_future_syms,
				   (mod->gpl_future_syms +
				    mod->num_gpl_future_syms));
		if (ks) {
			if (!gplok) {
				printk(KERN_WARNING "Symbol %s is being used "
				       "by a non-GPL module, which will not "
				       "be allowed in the future\n", name);
				printk(KERN_WARNING "Please see the file "
				       "Documentation/feature-removal-schedule.txt "
				       "in the kernel source tree for more "
				       "details.\n");
			}
			*crc = symversion(mod->gpl_future_crcs,
					  (ks - mod->gpl_future_syms));
			return ks->value;
		}
L
Linus Torvalds 已提交
278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335
	}
	DEBUGP("Failed to find symbol %s\n", name);
 	return 0;
}

/* Search for module by name: must hold module_mutex. */
static struct module *find_module(const char *name)
{
	struct module *mod;

	list_for_each_entry(mod, &modules, list) {
		if (strcmp(mod->name, name) == 0)
			return mod;
	}
	return NULL;
}

#ifdef CONFIG_SMP
/* Number of blocks used and allocated. */
static unsigned int pcpu_num_used, pcpu_num_allocated;
/* Size of each block.  -ve means used. */
static int *pcpu_size;

static int split_block(unsigned int i, unsigned short size)
{
	/* Reallocation required? */
	if (pcpu_num_used + 1 > pcpu_num_allocated) {
		int *new = kmalloc(sizeof(new[0]) * pcpu_num_allocated*2,
				   GFP_KERNEL);
		if (!new)
			return 0;

		memcpy(new, pcpu_size, sizeof(new[0])*pcpu_num_allocated);
		pcpu_num_allocated *= 2;
		kfree(pcpu_size);
		pcpu_size = new;
	}

	/* Insert a new subblock */
	memmove(&pcpu_size[i+1], &pcpu_size[i],
		sizeof(pcpu_size[0]) * (pcpu_num_used - i));
	pcpu_num_used++;

	pcpu_size[i+1] -= size;
	pcpu_size[i] = size;
	return 1;
}

static inline unsigned int block_size(int val)
{
	if (val < 0)
		return -val;
	return val;
}

/* Created by linker magic */
extern char __per_cpu_start[], __per_cpu_end[];

336 337
static void *percpu_modalloc(unsigned long size, unsigned long align,
			     const char *name)
L
Linus Torvalds 已提交
338 339 340 341 342
{
	unsigned long extra;
	unsigned int i;
	void *ptr;

343 344 345 346 347
	if (align > SMP_CACHE_BYTES) {
		printk(KERN_WARNING "%s: per-cpu alignment %li > %i\n",
		       name, align, SMP_CACHE_BYTES);
		align = SMP_CACHE_BYTES;
	}
L
Linus Torvalds 已提交
348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438

	ptr = __per_cpu_start;
	for (i = 0; i < pcpu_num_used; ptr += block_size(pcpu_size[i]), i++) {
		/* Extra for alignment requirement. */
		extra = ALIGN((unsigned long)ptr, align) - (unsigned long)ptr;
		BUG_ON(i == 0 && extra != 0);

		if (pcpu_size[i] < 0 || pcpu_size[i] < extra + size)
			continue;

		/* Transfer extra to previous block. */
		if (pcpu_size[i-1] < 0)
			pcpu_size[i-1] -= extra;
		else
			pcpu_size[i-1] += extra;
		pcpu_size[i] -= extra;
		ptr += extra;

		/* Split block if warranted */
		if (pcpu_size[i] - size > sizeof(unsigned long))
			if (!split_block(i, size))
				return NULL;

		/* Mark allocated */
		pcpu_size[i] = -pcpu_size[i];
		return ptr;
	}

	printk(KERN_WARNING "Could not allocate %lu bytes percpu data\n",
	       size);
	return NULL;
}

static void percpu_modfree(void *freeme)
{
	unsigned int i;
	void *ptr = __per_cpu_start + block_size(pcpu_size[0]);

	/* First entry is core kernel percpu data. */
	for (i = 1; i < pcpu_num_used; ptr += block_size(pcpu_size[i]), i++) {
		if (ptr == freeme) {
			pcpu_size[i] = -pcpu_size[i];
			goto free;
		}
	}
	BUG();

 free:
	/* Merge with previous? */
	if (pcpu_size[i-1] >= 0) {
		pcpu_size[i-1] += pcpu_size[i];
		pcpu_num_used--;
		memmove(&pcpu_size[i], &pcpu_size[i+1],
			(pcpu_num_used - i) * sizeof(pcpu_size[0]));
		i--;
	}
	/* Merge with next? */
	if (i+1 < pcpu_num_used && pcpu_size[i+1] >= 0) {
		pcpu_size[i] += pcpu_size[i+1];
		pcpu_num_used--;
		memmove(&pcpu_size[i+1], &pcpu_size[i+2],
			(pcpu_num_used - (i+1)) * sizeof(pcpu_size[0]));
	}
}

static unsigned int find_pcpusec(Elf_Ehdr *hdr,
				 Elf_Shdr *sechdrs,
				 const char *secstrings)
{
	return find_sec(hdr, sechdrs, secstrings, ".data.percpu");
}

static int percpu_modinit(void)
{
	pcpu_num_used = 2;
	pcpu_num_allocated = 2;
	pcpu_size = kmalloc(sizeof(pcpu_size[0]) * pcpu_num_allocated,
			    GFP_KERNEL);
	/* Static in-kernel percpu data (used). */
	pcpu_size[0] = -ALIGN(__per_cpu_end-__per_cpu_start, SMP_CACHE_BYTES);
	/* Free room. */
	pcpu_size[1] = PERCPU_ENOUGH_ROOM + pcpu_size[0];
	if (pcpu_size[1] < 0) {
		printk(KERN_ERR "No per-cpu room for modules.\n");
		pcpu_num_used = 1;
	}

	return 0;
}	
__initcall(percpu_modinit);
#else /* ... !CONFIG_SMP */
439 440
static inline void *percpu_modalloc(unsigned long size, unsigned long align,
				    const char *name)
L
Linus Torvalds 已提交
441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461
{
	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);
}
#endif /* CONFIG_SMP */

462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492
#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)                  \
{                                                                     \
        kfree(mod->field);                                            \
        mod->field = NULL;                                            \
}                                                                     \
static struct module_attribute modinfo_##field = {                    \
	.attr = { .name = __stringify(field), .mode = 0444,           \
		  .owner = THIS_MODULE },                             \
	.show = show_modinfo_##field,                                 \
	.setup = setup_modinfo_##field,                               \
	.test = modinfo_##field##_exists,                             \
	.free = free_modinfo_##field,                                 \
};

MODINFO_ATTR(version);
MODINFO_ATTR(srcversion);

493
#ifdef CONFIG_MODULE_UNLOAD
L
Linus Torvalds 已提交
494 495 496 497 498 499 500 501 502
/* Init the unload section of the module. */
static void module_unload_init(struct module *mod)
{
	unsigned int i;

	INIT_LIST_HEAD(&mod->modules_which_use_me);
	for (i = 0; i < NR_CPUS; i++)
		local_set(&mod->ref[i].count, 0);
	/* Hold reference count during initialization. */
I
Ingo Molnar 已提交
503
	local_set(&mod->ref[raw_smp_processor_id()].count, 1);
L
Linus Torvalds 已提交
504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573
	/* 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 */
static int use_module(struct module *a, struct module *b)
{
	struct module_use *use;
	if (b == NULL || already_uses(a, b)) return 1;

	if (!strong_try_module_get(b))
		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);
	return 1;
}

/* 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);
				/* There can be at most one match. */
				break;
			}
		}
	}
}

#ifdef CONFIG_MODULE_FORCE_UNLOAD
574
static inline int try_force_unload(unsigned int flags)
L
Linus Torvalds 已提交
575 576 577
{
	int ret = (flags & O_TRUNC);
	if (ret)
578
		add_taint(TAINT_FORCED_RMMOD);
L
Linus Torvalds 已提交
579 580 581
	return ret;
}
#else
582
static inline int try_force_unload(unsigned int flags)
L
Linus Torvalds 已提交
583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601
{
	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;

	/* If it's not unused, quit unless we are told to block. */
	if ((sref->flags & O_NONBLOCK) && module_refcount(sref->mod) != 0) {
602
		if (!(*sref->forced = try_force_unload(sref->flags)))
L
Linus Torvalds 已提交
603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633
			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)
{
	struct stopref sref = { mod, flags, forced };

	return stop_machine_run(__try_stop_module, &sref, NR_CPUS);
}

unsigned int module_refcount(struct module *mod)
{
	unsigned int i, total = 0;

	for (i = 0; i < NR_CPUS; i++)
		total += local_read(&mod->ref[i].count);
	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)
{
	/* Since we might sleep for some time, drop the semaphore first */
634
	mutex_unlock(&module_mutex);
L
Linus Torvalds 已提交
635 636 637 638 639 640 641 642
	for (;;) {
		DEBUGP("Looking at refcount...\n");
		set_current_state(TASK_UNINTERRUPTIBLE);
		if (module_refcount(mod) == 0)
			break;
		schedule();
	}
	current->state = TASK_RUNNING;
643
	mutex_lock(&module_mutex);
L
Linus Torvalds 已提交
644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659
}

asmlinkage long
sys_delete_module(const char __user *name_user, unsigned int flags)
{
	struct module *mod;
	char name[MODULE_NAME_LEN];
	int ret, forced = 0;

	if (!capable(CAP_SYS_MODULE))
		return -EPERM;

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

660
	if (mutex_lock_interruptible(&module_mutex) != 0)
L
Linus Torvalds 已提交
661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686
		return -EINTR;

	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 */
	if ((mod->init != NULL && mod->exit == NULL)
	    || mod->unsafe) {
687
		forced = try_force_unload(flags);
L
Linus Torvalds 已提交
688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708
		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);

	/* Final destruction now noone is using it. */
	if (mod->exit != NULL) {
709
		mutex_unlock(&module_mutex);
L
Linus Torvalds 已提交
710
		mod->exit();
711
		mutex_lock(&module_mutex);
L
Linus Torvalds 已提交
712 713 714 715
	}
	free_module(mod);

 out:
716
	mutex_unlock(&module_mutex);
L
Linus Torvalds 已提交
717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763
	return ret;
}

static void print_unload_info(struct seq_file *m, struct module *mod)
{
	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->unsafe) {
		printed_something = 1;
		seq_printf(m, "[unsafe],");
	}

	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;
	unsigned long flags;
	const unsigned long *crc;

	spin_lock_irqsave(&modlist_lock, flags);
	if (!__find_symbol(symbol, &owner, &crc, 1))
		BUG();
	module_put(owner);
	spin_unlock_irqrestore(&modlist_lock, flags);
}
EXPORT_SYMBOL(__symbol_put);

void symbol_put_addr(void *addr)
{
764
	struct module *modaddr;
L
Linus Torvalds 已提交
765

766 767
	if (core_kernel_text((unsigned long)addr))
		return;
L
Linus Torvalds 已提交
768

769 770 771
	if (!(modaddr = module_text_address((unsigned long)addr)))
		BUG();
	module_put(modaddr);
L
Linus Torvalds 已提交
772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807
}
EXPORT_SYMBOL_GPL(symbol_put_addr);

static ssize_t show_refcnt(struct module_attribute *mattr,
			   struct module *mod, char *buffer)
{
	/* sysfs holds a reference */
	return sprintf(buffer, "%u\n", module_refcount(mod)-1);
}

static struct module_attribute refcnt = {
	.attr = { .name = "refcnt", .mode = 0444, .owner = THIS_MODULE },
	.show = show_refcnt,
};

#else /* !CONFIG_MODULE_UNLOAD */
static void print_unload_info(struct seq_file *m, struct module *mod)
{
	/* We don't know the usage count, or what modules are using. */
	seq_printf(m, " - -");
}

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

static inline int use_module(struct module *a, struct module *b)
{
	return strong_try_module_get(b);
}

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

808 809 810 811 812 813 814 815 816
static struct module_attribute *modinfo_attrs[] = {
	&modinfo_version,
	&modinfo_srcversion,
#ifdef CONFIG_MODULE_UNLOAD
	&refcnt,
#endif
	NULL,
};

L
Linus Torvalds 已提交
817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852
static const char vermagic[] = VERMAGIC_STRING;

#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;

	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;
		printk("%s: disagrees about version of symbol %s\n",
		       mod->name, symname);
		DEBUGP("Found checksum %lX vs module %lX\n",
		       *crc, versions[i].crc);
		return 0;
	}
	/* Not in module's version table.  OK, but that taints the kernel. */
	if (!(tainted & TAINT_FORCED_MODULE)) {
		printk("%s: no version for \"%s\" found: kernel tainted.\n",
		       mod->name, symname);
853
		add_taint(TAINT_FORCED_MODULE);
L
Linus Torvalds 已提交
854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008
	}
	return 1;
}

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

	if (!__find_symbol("struct_module", &owner, &crc, 1))
		BUG();
	return check_version(sechdrs, versindex, "struct_module", mod,
			     crc);
}

/* First part is kernel version, which we ignore. */
static inline int same_magic(const char *amagic, const char *bmagic)
{
	amagic += strcspn(amagic, " ");
	bmagic += strcspn(bmagic, " ");
	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;
}

static inline int same_magic(const char *amagic, const char *bmagic)
{
	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. */
static unsigned long resolve_symbol(Elf_Shdr *sechdrs,
				    unsigned int versindex,
				    const char *name,
				    struct module *mod)
{
	struct module *owner;
	unsigned long ret;
	const unsigned long *crc;

	ret = __find_symbol(name, &owner, &crc, mod->license_gplok);
	if (ret) {
		/* use_module can fail due to OOM, or module unloading */
		if (!check_version(sechdrs, versindex, name, mod, crc) ||
		    !use_module(mod, owner))
			ret = 0;
	}
	return ret;
}


/*
 * /sys/module/foo/sections stuff
 * J. Corbet <corbet@lwn.net>
 */
#ifdef CONFIG_KALLSYMS
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);
}

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;
	
	/* Count loaded sections and allocate structures */
	for (i = 0; i < nsect; i++)
		if (sechdrs[i].sh_flags & SHF_ALLOC)
			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]);
	if (! (sect_attrs = kmalloc(size[0] + size[1], GFP_KERNEL)))
		return;

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

	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;
		sattr->address = sechdrs[i].sh_addr;
		strlcpy(sattr->name, secstrings + sechdrs[i].sh_name,
			MODULE_SECT_NAME_LEN);
		sattr->mattr.show = module_sect_show;
		sattr->mattr.store = NULL;
		sattr->mattr.attr.name = sattr->name;
		sattr->mattr.attr.owner = mod;
		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:
	kfree(sect_attrs);
}

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. */
		kfree(mod->sect_attrs);
		mod->sect_attrs = NULL;
	}
}


#else
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)
{
}
#endif /* CONFIG_KALLSYMS */

1009 1010 1011
static int module_add_modinfo_attrs(struct module *mod)
{
	struct module_attribute *attr;
1012
	struct module_attribute *temp_attr;
1013 1014 1015
	int error = 0;
	int i;

1016 1017 1018 1019 1020 1021 1022
	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;
1023 1024
	for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
		if (!attr->test ||
1025 1026 1027 1028 1029 1030
		    (attr->test && attr->test(mod))) {
			memcpy(temp_attr, attr, sizeof(*temp_attr));
			temp_attr->attr.owner = mod;
			error = sysfs_create_file(&mod->mkobj.kobj,&temp_attr->attr);
			++temp_attr;
		}
1031 1032 1033 1034 1035 1036 1037 1038 1039
	}
	return error;
}

static void module_remove_modinfo_attrs(struct module *mod)
{
	struct module_attribute *attr;
	int i;

1040 1041 1042 1043
	for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
		/* pick a field to test for end of list */
		if (!attr->attr.name)
			break;
1044
		sysfs_remove_file(&mod->mkobj.kobj,&attr->attr);
1045 1046
		if (attr->free)
			attr->free(mod);
1047
	}
1048
	kfree(mod->modinfo_attrs);
1049
}
L
Linus Torvalds 已提交
1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070

static int mod_sysfs_setup(struct module *mod,
			   struct kernel_param *kparam,
			   unsigned int num_params)
{
	int err;

	memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
	err = kobject_set_name(&mod->mkobj.kobj, "%s", mod->name);
	if (err)
		goto out;
	kobj_set_kset_s(&mod->mkobj, module_subsys);
	mod->mkobj.mod = mod;
	err = kobject_register(&mod->mkobj.kobj);
	if (err)
		goto out;

	err = module_param_sysfs_setup(mod, kparam, num_params);
	if (err)
		goto out_unreg;

1071 1072 1073 1074
	err = module_add_modinfo_attrs(mod);
	if (err)
		goto out_unreg;

L
Linus Torvalds 已提交
1075 1076 1077 1078 1079 1080 1081 1082 1083 1084
	return 0;

out_unreg:
	kobject_unregister(&mod->mkobj.kobj);
out:
	return err;
}

static void mod_kobject_remove(struct module *mod)
{
1085
	module_remove_modinfo_attrs(mod);
L
Linus Torvalds 已提交
1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109
	module_param_sysfs_remove(mod);

	kobject_unregister(&mod->mkobj.kobj);
}

/*
 * 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;
}

/* Free a module, remove from lists, etc (must hold module mutex). */
static void free_module(struct module *mod)
{
	/* Delete from various lists */
	stop_machine_run(__unlink_module, mod, NR_CPUS);
	remove_sect_attrs(mod);
	mod_kobject_remove(mod);

1110 1111
	unwind_remove_table(mod->unwind_info, 0);

L
Linus Torvalds 已提交
1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143
	/* Arch-specific cleanup. */
	module_arch_cleanup(mod);

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

	/* This may be NULL, but that's OK */
	module_free(mod, mod->module_init);
	kfree(mod->args);
	if (mod->percpu)
		percpu_modfree(mod->percpu);

	/* Finally, free the core (containing the module structure) */
	module_free(mod, mod->module_core);
}

void *__symbol_get(const char *symbol)
{
	struct module *owner;
	unsigned long value, flags;
	const unsigned long *crc;

	spin_lock_irqsave(&modlist_lock, flags);
	value = __find_symbol(symbol, &owner, &crc, 1);
	if (value && !strong_try_module_get(owner))
		value = 0;
	spin_unlock_irqrestore(&modlist_lock, flags);

	return (void *)value;
}
EXPORT_SYMBOL_GPL(__symbol_get);

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 1174 1175 1176
/*
 * Ensure that an exported symbol [global namespace] does not already exist
 * in the Kernel or in some other modules exported symbol table.
 */
static int verify_export_symbols(struct module *mod)
{
	const char *name = NULL;
	unsigned long i, ret = 0;
	struct module *owner;
	const unsigned long *crc;

	for (i = 0; i < mod->num_syms; i++)
	        if (__find_symbol(mod->syms[i].name, &owner, &crc, 1)) {
			name = mod->syms[i].name;
			ret = -ENOEXEC;
			goto dup;
		}

	for (i = 0; i < mod->num_gpl_syms; i++)
	        if (__find_symbol(mod->gpl_syms[i].name, &owner, &crc, 1)) {
			name = mod->gpl_syms[i].name;
			ret = -ENOEXEC;
			goto dup;
		}

dup:
	if (ret)
		printk(KERN_ERR "%s: exports duplicate symbol %s (owned by %s)\n",
			mod->name, name, module_name(owner));

	return ret;
}

L
Linus Torvalds 已提交
1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317
/* Change all symbols so that sh_value encodes the pointer directly. */
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;

	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:
			sym[i].st_value
			  = resolve_symbol(sechdrs, versindex,
					   strtab + sym[i].st_name, mod);

			/* Ok if resolved.  */
			if (sym[i].st_value != 0)
				break;
			/* Ok if weak.  */
			if (ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
				break;

			printk(KERN_WARNING "%s: Unknown symbol %s\n",
			       mod->name, strtab + sym[i].st_name);
			ret = -ENOENT;
			break;

		default:
			/* Divert to percpu allocation if a percpu var. */
			if (sym[i].st_shndx == pcpuindex)
				secbase = (unsigned long)mod->percpu;
			else
				secbase = sechdrs[sym[i].st_shndx].sh_addr;
			sym[i].st_value += secbase;
			break;
		}
	}

	return ret;
}

/* Update size with this section: return offset. */
static long get_offset(unsigned long *size, Elf_Shdr *sechdr)
{
	long ret;

	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
			    || strncmp(secstrings + s->sh_name,
				       ".init", 5) == 0)
				continue;
			s->sh_entsize = get_offset(&mod->core_size, s);
			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
			    || strncmp(secstrings + s->sh_name,
				       ".init", 5) != 0)
				continue;
			s->sh_entsize = (get_offset(&mod->init_size, s)
					 | 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";

	mod->license_gplok = license_is_gpl_compatible(license);
	if (!mod->license_gplok && !(tainted & TAINT_PROPRIETARY_MODULE)) {
		printk(KERN_WARNING "%s: module license '%s' taints kernel.\n",
		       mod->name, license);
1318
		add_taint(TAINT_PROPRIETARY_MODULE);
L
Linus Torvalds 已提交
1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355
	}
}

/* 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;
}

static char *get_modinfo(Elf_Shdr *sechdrs,
			 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;
}

1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370
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));
	}
}

L
Linus Torvalds 已提交
1371 1372 1373
#ifdef CONFIG_KALLSYMS
int is_exported(const char *name, const struct module *mod)
{
1374 1375 1376
	if (!mod && lookup_symbol(name, __start___ksymtab, __stop___ksymtab))
		return 1;
	else
1377
		if (mod && lookup_symbol(name, mod->syms, mod->syms + mod->num_syms))
L
Linus Torvalds 已提交
1378
			return 1;
1379 1380
		else
			return 0;
L
Linus Torvalds 已提交
1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459
}

/* 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';
	}
	if (strncmp(secstrings + sechdrs[sym->st_shndx].sh_name,
		    ".debug", strlen(".debug")) == 0)
		return 'n';
	return '?';
}

static void add_kallsyms(struct module *mod,
			 Elf_Shdr *sechdrs,
			 unsigned int symindex,
			 unsigned int strindex,
			 const char *secstrings)
{
	unsigned int i;

	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);
}
#else
static inline void add_kallsyms(struct module *mod,
				Elf_Shdr *sechdrs,
				unsigned int symindex,
				unsigned int strindex,
				const char *secstrings)
{
}
#endif /* CONFIG_KALLSYMS */

/* Allocate and load the module: note that size of section 0 is always
   zero, and we rely on this for optional sections. */
static struct module *load_module(void __user *umod,
				  unsigned long len,
				  const char __user *uargs)
{
	Elf_Ehdr *hdr;
	Elf_Shdr *sechdrs;
	char *secstrings, *args, *modmagic, *strtab = NULL;
A
Andrew Morton 已提交
1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480
	unsigned int i;
	unsigned int symindex = 0;
	unsigned int strindex = 0;
	unsigned int setupindex;
	unsigned int exindex;
	unsigned int exportindex;
	unsigned int modindex;
	unsigned int obsparmindex;
	unsigned int infoindex;
	unsigned int gplindex;
	unsigned int crcindex;
	unsigned int gplcrcindex;
	unsigned int versindex;
	unsigned int pcpuindex;
	unsigned int gplfutureindex;
	unsigned int gplfuturecrcindex;
	unsigned int unwindex = 0;
	unsigned int unusedindex;
	unsigned int unusedcrcindex;
	unsigned int unusedgplindex;
	unsigned int unusedgplcrcindex;
L
Linus Torvalds 已提交
1481 1482 1483 1484
	struct module *mod;
	long err = 0;
	void *percpu = NULL, *ptr = NULL; /* Stops spurious gcc warning */
	struct exception_table_entry *extable;
1485
	mm_segment_t old_fs;
L
Linus Torvalds 已提交
1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559

	DEBUGP("load_module: umod=%p, len=%lu, uargs=%p\n",
	       umod, len, uargs);
	if (len < sizeof(*hdr))
		return ERR_PTR(-ENOEXEC);

	/* Suck in entire file: we'll want most of it. */
	/* vmalloc barfs on "unusual" numbers.  Check here */
	if (len > 64 * 1024 * 1024 || (hdr = vmalloc(len)) == NULL)
		return ERR_PTR(-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, 4) != 0
	    || hdr->e_type != ET_REL
	    || !elf_check_arch(hdr)
	    || hdr->e_shentsize != sizeof(*sechdrs)) {
		err = -ENOEXEC;
		goto free_hdr;
	}

	if (len < hdr->e_shoff + hdr->e_shnum * sizeof(Elf_Shdr))
		goto truncated;

	/* 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 */
		if (strncmp(secstrings+sechdrs[i].sh_name, ".exit", 5) == 0)
			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;
	}
	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;
	}

	/* Optional sections */
	exportindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab");
	gplindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_gpl");
1560
	gplfutureindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_gpl_future");
1561 1562
	unusedindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_unused");
	unusedgplindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_unused_gpl");
L
Linus Torvalds 已提交
1563 1564
	crcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab");
	gplcrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_gpl");
1565
	gplfuturecrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_gpl_future");
1566 1567
	unusedcrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_unused");
	unusedgplcrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_unused_gpl");
L
Linus Torvalds 已提交
1568 1569 1570 1571 1572 1573
	setupindex = find_sec(hdr, sechdrs, secstrings, "__param");
	exindex = find_sec(hdr, sechdrs, secstrings, "__ex_table");
	obsparmindex = find_sec(hdr, sechdrs, secstrings, "__obsparm");
	versindex = find_sec(hdr, sechdrs, secstrings, "__versions");
	infoindex = find_sec(hdr, sechdrs, secstrings, ".modinfo");
	pcpuindex = find_pcpusec(hdr, sechdrs, secstrings);
1574 1575 1576
#ifdef ARCH_UNWIND_SECTION_NAME
	unwindex = find_sec(hdr, sechdrs, secstrings, ARCH_UNWIND_SECTION_NAME);
#endif
L
Linus Torvalds 已提交
1577 1578 1579 1580 1581 1582 1583 1584

	/* Don't keep modinfo section */
	sechdrs[infoindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
#ifdef CONFIG_KALLSYMS
	/* Keep symbol and string tables for decoding later. */
	sechdrs[symindex].sh_flags |= SHF_ALLOC;
	sechdrs[strindex].sh_flags |= SHF_ALLOC;
#endif
1585 1586
	if (unwindex)
		sechdrs[unwindex].sh_flags |= SHF_ALLOC;
L
Linus Torvalds 已提交
1587 1588 1589 1590 1591 1592 1593 1594 1595 1596

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

	modmagic = get_modinfo(sechdrs, infoindex, "vermagic");
	/* This is allowed: modprobe --force will invalidate it. */
	if (!modmagic) {
1597
		add_taint(TAINT_FORCED_MODULE);
L
Linus Torvalds 已提交
1598 1599 1600 1601 1602 1603 1604 1605 1606 1607
		printk(KERN_WARNING "%s: no version magic, tainting kernel.\n",
		       mod->name);
	} else if (!same_magic(modmagic, vermagic)) {
		printk(KERN_ERR "%s: version magic '%s' should be '%s'\n",
		       mod->name, modmagic, vermagic);
		err = -ENOEXEC;
		goto free_hdr;
	}

	/* Now copy in args */
1608 1609 1610
	args = strndup_user(uargs, ~0UL >> 1);
	if (IS_ERR(args)) {
		err = PTR_ERR(args);
L
Linus Torvalds 已提交
1611 1612
		goto free_hdr;
	}
1613

L
Linus Torvalds 已提交
1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628
	if (find_module(mod->name)) {
		err = -EEXIST;
		goto free_mod;
	}

	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. */
		percpu = percpu_modalloc(sechdrs[pcpuindex].sh_size,
1629 1630
					 sechdrs[pcpuindex].sh_addralign,
					 mod->name);
L
Linus Torvalds 已提交
1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690
		if (!percpu) {
			err = -ENOMEM;
			goto free_mod;
		}
		sechdrs[pcpuindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
		mod->percpu = percpu;
	}

	/* 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);

	/* Do the allocs. */
	ptr = module_alloc(mod->core_size);
	if (!ptr) {
		err = -ENOMEM;
		goto free_percpu;
	}
	memset(ptr, 0, mod->core_size);
	mod->module_core = ptr;

	ptr = module_alloc(mod->init_size);
	if (!ptr && mod->init_size) {
		err = -ENOMEM;
		goto free_core;
	}
	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;

	/* Now we've moved module, initialize linked lists, etc. */
	module_unload_init(mod);

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

1691 1692 1693 1694 1695
	if (strcmp(mod->name, "ndiswrapper") == 0)
		add_taint(TAINT_PROPRIETARY_MODULE);
	if (strcmp(mod->name, "driverloader") == 0)
		add_taint(TAINT_PROPRIETARY_MODULE);

1696 1697 1698
	/* Set up MODINFO_ATTR fields */
	setup_modinfo(mod, sechdrs, infoindex);

L
Linus Torvalds 已提交
1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713
	/* 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;

	/* Set up EXPORTed & EXPORT_GPLed symbols (section 0 is 0 length) */
	mod->num_syms = sechdrs[exportindex].sh_size / sizeof(*mod->syms);
	mod->syms = (void *)sechdrs[exportindex].sh_addr;
	if (crcindex)
		mod->crcs = (void *)sechdrs[crcindex].sh_addr;
	mod->num_gpl_syms = sechdrs[gplindex].sh_size / sizeof(*mod->gpl_syms);
	mod->gpl_syms = (void *)sechdrs[gplindex].sh_addr;
	if (gplcrcindex)
		mod->gpl_crcs = (void *)sechdrs[gplcrcindex].sh_addr;
1714 1715
	mod->num_gpl_future_syms = sechdrs[gplfutureindex].sh_size /
					sizeof(*mod->gpl_future_syms);
1716 1717 1718 1719
	mod->num_unused_syms = sechdrs[unusedindex].sh_size /
					sizeof(*mod->unused_syms);
	mod->num_unused_gpl_syms = sechdrs[unusedgplindex].sh_size /
					sizeof(*mod->unused_gpl_syms);
1720 1721 1722
	mod->gpl_future_syms = (void *)sechdrs[gplfutureindex].sh_addr;
	if (gplfuturecrcindex)
		mod->gpl_future_crcs = (void *)sechdrs[gplfuturecrcindex].sh_addr;
L
Linus Torvalds 已提交
1723

1724 1725 1726 1727 1728 1729 1730
	mod->unused_syms = (void *)sechdrs[unusedindex].sh_addr;
	if (unusedcrcindex)
		mod->unused_crcs = (void *)sechdrs[unusedcrcindex].sh_addr;
	mod->unused_gpl_syms = (void *)sechdrs[unusedgplindex].sh_addr;
	if (unusedgplcrcindex)
		mod->unused_crcs = (void *)sechdrs[unusedgplcrcindex].sh_addr;

L
Linus Torvalds 已提交
1731 1732
#ifdef CONFIG_MODVERSIONS
	if ((mod->num_syms && !crcindex) || 
1733
	    (mod->num_gpl_syms && !gplcrcindex) ||
1734 1735 1736
	    (mod->num_gpl_future_syms && !gplfuturecrcindex) ||
	    (mod->num_unused_syms && !unusedcrcindex) ||
	    (mod->num_unused_gpl_syms && !unusedgplcrcindex)) {
L
Linus Torvalds 已提交
1737 1738
		printk(KERN_WARNING "%s: No versions for exported symbols."
		       " Tainting kernel.\n", mod->name);
1739
		add_taint(TAINT_FORCED_MODULE);
L
Linus Torvalds 已提交
1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764
	}
#endif

	/* 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)
			goto cleanup;
	}

1765 1766 1767 1768 1769 1770
        /* Find duplicate symbols */
	err = verify_export_symbols(mod);

	if (err < 0)
		goto cleanup;

L
Linus Torvalds 已提交
1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785
  	/* Set up and sort exception table */
	mod->num_exentries = sechdrs[exindex].sh_size / sizeof(*mod->extable);
	mod->extable = extable = (void *)sechdrs[exindex].sh_addr;
	sort_extable(extable, extable + mod->num_exentries);

	/* Finally, copy percpu area over. */
	percpu_modcopy(mod->percpu, (void *)sechdrs[pcpuindex].sh_addr,
		       sechdrs[pcpuindex].sh_size);

	add_kallsyms(mod, sechdrs, symindex, strindex, secstrings);

	err = module_finalize(hdr, sechdrs, mod);
	if (err < 0)
		goto cleanup;

1786 1787 1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803
	/* 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
1804
	mod->args = args;
R
Rusty Russell 已提交
1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815
	if (obsparmindex)
		printk(KERN_WARNING "%s: Ignoring obsolete parameters\n",
		       mod->name);

	/* Size of section 0 is 0, so this works well if no params */
	err = parse_args(mod->name, mod->args,
			 (struct kernel_param *)
			 sechdrs[setupindex].sh_addr,
			 sechdrs[setupindex].sh_size
			 / sizeof(struct kernel_param),
			 NULL);
L
Linus Torvalds 已提交
1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827
	if (err < 0)
		goto arch_cleanup;

	err = mod_sysfs_setup(mod, 
			      (struct kernel_param *)
			      sechdrs[setupindex].sh_addr,
			      sechdrs[setupindex].sh_size
			      / sizeof(struct kernel_param));
	if (err < 0)
		goto arch_cleanup;
	add_sect_attrs(mod, hdr->e_shnum, secstrings, sechdrs);

1828 1829 1830 1831 1832
	/* Size of section 0 is 0, so this works well if no unwind info. */
	mod->unwind_info = unwind_add_table(mod,
	                                    (void *)sechdrs[unwindex].sh_addr,
	                                    sechdrs[unwindex].sh_size);

L
Linus Torvalds 已提交
1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852
	/* Get rid of temporary copy */
	vfree(hdr);

	/* Done! */
	return mod;

 arch_cleanup:
	module_arch_cleanup(mod);
 cleanup:
	module_unload_free(mod);
	module_free(mod, mod->module_init);
 free_core:
	module_free(mod, mod->module_core);
 free_percpu:
	if (percpu)
		percpu_modfree(percpu);
 free_mod:
	kfree(args);
 free_hdr:
	vfree(hdr);
1853
	return ERR_PTR(err);
L
Linus Torvalds 已提交
1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885

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

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

/* This is where the real work happens */
asmlinkage long
sys_init_module(void __user *umod,
		unsigned long len,
		const char __user *uargs)
{
	struct module *mod;
	int ret = 0;

	/* Must have permission */
	if (!capable(CAP_SYS_MODULE))
		return -EPERM;

	/* Only one module load at a time, please */
1886
	if (mutex_lock_interruptible(&module_mutex) != 0)
L
Linus Torvalds 已提交
1887 1888 1889 1890 1891
		return -EINTR;

	/* Do all the hard work */
	mod = load_module(umod, len, uargs);
	if (IS_ERR(mod)) {
1892
		mutex_unlock(&module_mutex);
L
Linus Torvalds 已提交
1893 1894 1895 1896 1897 1898 1899 1900
		return PTR_ERR(mod);
	}

	/* Now sew it into the lists.  They won't access us, since
           strong_try_module_get() will fail. */
	stop_machine_run(__link_module, mod, NR_CPUS);

	/* Drop lock so they can recurse */
1901
	mutex_unlock(&module_mutex);
L
Linus Torvalds 已提交
1902

1903 1904
	blocking_notifier_call_chain(&module_notify_list,
			MODULE_STATE_COMING, mod);
L
Linus Torvalds 已提交
1905 1906 1907 1908 1909 1910 1911 1912

	/* Start the module */
	if (mod->init != NULL)
		ret = mod->init();
	if (ret < 0) {
		/* Init routine failed: abort.  Try to protect us from
                   buggy refcounters. */
		mod->state = MODULE_STATE_GOING;
1913
		synchronize_sched();
L
Linus Torvalds 已提交
1914 1915 1916 1917 1918
		if (mod->unsafe)
			printk(KERN_ERR "%s: module is now stuck!\n",
			       mod->name);
		else {
			module_put(mod);
1919
			mutex_lock(&module_mutex);
L
Linus Torvalds 已提交
1920
			free_module(mod);
1921
			mutex_unlock(&module_mutex);
L
Linus Torvalds 已提交
1922 1923 1924 1925 1926
		}
		return ret;
	}

	/* Now it's a first class citizen! */
1927
	mutex_lock(&module_mutex);
L
Linus Torvalds 已提交
1928 1929 1930
	mod->state = MODULE_STATE_LIVE;
	/* Drop initial reference. */
	module_put(mod);
1931
	unwind_remove_table(mod->unwind_info, 1);
L
Linus Torvalds 已提交
1932 1933 1934 1935
	module_free(mod, mod->module_init);
	mod->module_init = NULL;
	mod->init_size = 0;
	mod->init_text_size = 0;
1936
	mutex_unlock(&module_mutex);
L
Linus Torvalds 已提交
1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025

	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 $d.
 */
static inline int is_arm_mapping_symbol(const char *str)
{
	return str[0] == '$' && strchr("atd", str[1]) 
	       && (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 */
	if (within(addr, mod->module_init, mod->init_size))
		nextval = (unsigned long)mod->module_init+mod->init_text_size;
	else 
		nextval = (unsigned long)mod->module_core+mod->core_text_size;

	/* Scan for closest preceeding symbol, and next symbol. (ELF
           starts real symbols at 1). */
	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;

	*size = nextval - mod->symtab[best].st_value;
	*offset = addr - mod->symtab[best].st_value;
	return mod->strtab + mod->symtab[best].st_name;
}

/* For kallsyms to ask for address resolution.  NULL means not found.
   We don't lock, as this is used for oops resolution and races are a
   lesser concern. */
const char *module_address_lookup(unsigned long addr,
				  unsigned long *size,
				  unsigned long *offset,
				  char **modname)
{
	struct module *mod;

	list_for_each_entry(mod, &modules, list) {
		if (within(addr, mod->module_init, mod->init_size)
		    || within(addr, mod->module_core, mod->core_size)) {
			*modname = mod->name;
			return get_ksymbol(mod, addr, size, offset);
		}
	}
	return NULL;
}

struct module *module_get_kallsym(unsigned int symnum,
				  unsigned long *value,
				  char *type,
				  char namebuf[128])
{
	struct module *mod;

2026
	mutex_lock(&module_mutex);
L
Linus Torvalds 已提交
2027 2028 2029 2030 2031 2032 2033
	list_for_each_entry(mod, &modules, list) {
		if (symnum < mod->num_symtab) {
			*value = mod->symtab[symnum].st_value;
			*type = mod->symtab[symnum].st_info;
			strncpy(namebuf,
				mod->strtab + mod->symtab[symnum].st_name,
				127);
2034
			mutex_unlock(&module_mutex);
L
Linus Torvalds 已提交
2035 2036 2037 2038
			return mod;
		}
		symnum -= mod->num_symtab;
	}
2039
	mutex_unlock(&module_mutex);
L
Linus Torvalds 已提交
2040 2041 2042 2043 2044 2045 2046 2047
	return NULL;
}

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

	for (i = 0; i < mod->num_symtab; i++)
2048 2049
		if (strcmp(name, mod->strtab+mod->symtab[i].st_name) == 0 &&
		    mod->symtab[i].st_info != 'U')
L
Linus Torvalds 已提交
2050 2051 2052 2053 2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067 2068 2069 2070 2071 2072 2073 2074 2075 2076 2077 2078 2079 2080 2081
			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. */
	if ((colon = strchr(name, ':')) != NULL) {
		*colon = '\0';
		if ((mod = find_module(name)) != NULL)
			ret = mod_find_symname(mod, colon+1);
		*colon = ':';
	} else {
		list_for_each_entry(mod, &modules, list)
			if ((ret = mod_find_symname(mod, name)) != 0)
				break;
	}
	return ret;
}
#endif /* CONFIG_KALLSYMS */

/* Called by the /proc file system to return a list of modules. */
static void *m_start(struct seq_file *m, loff_t *pos)
{
	struct list_head *i;
	loff_t n = 0;

2082
	mutex_lock(&module_mutex);
L
Linus Torvalds 已提交
2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102
	list_for_each(i, &modules) {
		if (n++ == *pos)
			break;
	}
	if (i == &modules)
		return NULL;
	return i;
}

static void *m_next(struct seq_file *m, void *p, loff_t *pos)
{
	struct list_head *i = p;
	(*pos)++;
	if (i->next == &modules)
		return NULL;
	return i->next;
}

static void m_stop(struct seq_file *m, void *p)
{
2103
	mutex_unlock(&module_mutex);
L
Linus Torvalds 已提交
2104 2105 2106 2107 2108 2109 2110 2111 2112 2113 2114 2115 2116 2117 2118 2119 2120 2121 2122 2123 2124 2125 2126 2127 2128 2129 2130 2131 2132 2133 2134 2135 2136 2137 2138 2139 2140 2141 2142 2143 2144 2145 2146 2147 2148 2149 2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161
}

static int m_show(struct seq_file *m, void *p)
{
	struct module *mod = list_entry(p, struct module, list);
	seq_printf(m, "%s %lu",
		   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);

	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 -.
*/
struct seq_operations modules_op = {
	.start	= m_start,
	.next	= m_next,
	.stop	= m_stop,
	.show	= m_show
};

/* Given an address, look for it in the module exception tables. */
const struct exception_table_entry *search_module_extables(unsigned long addr)
{
	unsigned long flags;
	const struct exception_table_entry *e = NULL;
	struct module *mod;

	spin_lock_irqsave(&modlist_lock, flags);
	list_for_each_entry(mod, &modules, list) {
		if (mod->num_exentries == 0)
			continue;
				
		e = search_extable(mod->extable,
				   mod->extable + mod->num_exentries - 1,
				   addr);
		if (e)
			break;
	}
	spin_unlock_irqrestore(&modlist_lock, flags);

	/* Now, if we found one, we are running inside it now, hence
           we cannot unload the module, hence no refcnt needed. */
	return e;
}

2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 2172 2173 2174 2175 2176 2177 2178 2179 2180 2181 2182 2183 2184
/*
 * Is this a valid module address?
 */
int is_module_address(unsigned long addr)
{
	unsigned long flags;
	struct module *mod;

	spin_lock_irqsave(&modlist_lock, flags);

	list_for_each_entry(mod, &modules, list) {
		if (within(addr, mod->module_core, mod->core_size)) {
			spin_unlock_irqrestore(&modlist_lock, flags);
			return 1;
		}
	}

	spin_unlock_irqrestore(&modlist_lock, flags);

	return 0;
}


L
Linus Torvalds 已提交
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 2215 2216 2217 2218 2219 2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240 2241 2242
/* Is this a valid kernel address?  We don't grab the lock: we are oopsing. */
struct module *__module_text_address(unsigned long addr)
{
	struct module *mod;

	list_for_each_entry(mod, &modules, list)
		if (within(addr, mod->module_init, mod->init_text_size)
		    || within(addr, mod->module_core, mod->core_text_size))
			return mod;
	return NULL;
}

struct module *module_text_address(unsigned long addr)
{
	struct module *mod;
	unsigned long flags;

	spin_lock_irqsave(&modlist_lock, flags);
	mod = __module_text_address(addr);
	spin_unlock_irqrestore(&modlist_lock, flags);

	return mod;
}

/* Don't grab lock, we're oopsing. */
void print_modules(void)
{
	struct module *mod;

	printk("Modules linked in:");
	list_for_each_entry(mod, &modules, list)
		printk(" %s", mod->name);
	printk("\n");
}

void module_add_driver(struct module *mod, struct device_driver *drv)
{
	if (!mod || !drv)
		return;

	/* Don't check return code; this call is idempotent */
	sysfs_create_link(&drv->kobj, &mod->mkobj.kobj, "module");
}
EXPORT_SYMBOL(module_add_driver);

void module_remove_driver(struct device_driver *drv)
{
	if (!drv)
		return;
	sysfs_remove_link(&drv->kobj, "module");
}
EXPORT_SYMBOL(module_remove_driver);

#ifdef CONFIG_MODVERSIONS
/* Generate the signature for struct module here, too, for modversions. */
void struct_module(struct module *mod) { return; }
EXPORT_SYMBOL(struct_module);
#endif