module.c 59.3 KB
Newer Older
L
Linus Torvalds 已提交
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22
/* Rewritten by Rusty Russell, on the backs of many others...
   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/config.h>
#include <linux/module.h>
#include <linux/moduleloader.h>
#include <linux/init.h>
23
#include <linux/kernel.h>
L
Linus Torvalds 已提交
24 25 26 27 28 29 30
#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>
31
#include <linux/capability.h>
L
Linus Torvalds 已提交
32 33 34 35 36 37 38 39
#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>
40
#include <linux/string.h>
41
#include <linux/sched.h>
L
Linus Torvalds 已提交
42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128
#include <asm/uaccess.h>
#include <asm/semaphore.h>
#include <asm/cacheflush.h>

#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 */
static DECLARE_MUTEX(module_mutex);
static LIST_HEAD(modules);

static DECLARE_MUTEX(notify_mutex);
static struct notifier_block * module_notify_list;

int register_module_notifier(struct notifier_block * nb)
{
	int err;
	down(&notify_mutex);
	err = notifier_chain_register(&module_notify_list, nb);
	up(&notify_mutex);
	return err;
}
EXPORT_SYMBOL(register_module_notifier);

int unregister_module_notifier(struct notifier_block * nb)
{
	int err;
	down(&notify_mutex);
	err = notifier_chain_unregister(&module_notify_list, nb);
	up(&notify_mutex);
	return err;
}
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[];
129 130
extern const struct kernel_symbol __start___ksymtab_gpl_future[];
extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
L
Linus Torvalds 已提交
131 132
extern const unsigned long __start___kcrctab[];
extern const unsigned long __start___kcrctab_gpl[];
133
extern const unsigned long __start___kcrctab_gpl_future[];
L
Linus Torvalds 已提交
134 135 136 137 138 139 140

#ifndef CONFIG_MODVERSIONS
#define symversion(base, idx) NULL
#else
#define symversion(base, idx) ((base) ? ((base) + (idx)) : NULL)
#endif

141 142 143 144 145 146 147 148 149 150 151 152
/* 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;
}

L
Linus Torvalds 已提交
153 154 155 156 157 158 159
/* 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;
160
	const struct kernel_symbol *ks;
L
Linus Torvalds 已提交
161 162 163

	/* Core kernel first. */ 
	*owner = NULL;
164 165 166 167
	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
168 169
	}
	if (gplok) {
170 171 172 173 174 175 176
		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
177
	}
178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193
	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
194 195 196 197

	/* Now try modules. */ 
	list_for_each_entry(mod, &modules, list) {
		*owner = mod;
198 199 200 201 202
		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
203 204

		if (gplok) {
205 206 207 208 209 210
			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
211 212
			}
		}
213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229
		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
230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305
	}
	DEBUGP("Failed to find symbol %s\n", name);
 	return 0;
}

/* Find a symbol in this elf symbol table */
static unsigned long find_local_symbol(Elf_Shdr *sechdrs,
				       unsigned int symindex,
				       const char *strtab,
				       const char *name)
{
	unsigned int i;
	Elf_Sym *sym = (void *)sechdrs[symindex].sh_addr;

	/* Search (defined) internal symbols first. */
	for (i = 1; i < sechdrs[symindex].sh_size/sizeof(*sym); i++) {
		if (sym[i].st_shndx != SHN_UNDEF
		    && strcmp(name, strtab + sym[i].st_name) == 0)
			return sym[i].st_value;
	}
	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[];

306 307
static void *percpu_modalloc(unsigned long size, unsigned long align,
			     const char *name)
L
Linus Torvalds 已提交
308 309 310 311 312
{
	unsigned long extra;
	unsigned int i;
	void *ptr;

313 314 315 316 317
	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
318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408

	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 */
409 410
static inline void *percpu_modalloc(unsigned long size, unsigned long align,
				    const char *name)
L
Linus Torvalds 已提交
411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431
{
	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 */

432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462
#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);

463
#ifdef CONFIG_MODULE_UNLOAD
L
Linus Torvalds 已提交
464 465 466 467 468 469 470 471 472
/* 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
473
	local_set(&mod->ref[raw_smp_processor_id()].count, 1);
L
Linus Torvalds 已提交
474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543
	/* 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
544
static inline int try_force_unload(unsigned int flags)
L
Linus Torvalds 已提交
545 546 547
{
	int ret = (flags & O_TRUNC);
	if (ret)
548
		add_taint(TAINT_FORCED_RMMOD);
L
Linus Torvalds 已提交
549 550 551
	return ret;
}
#else
552
static inline int try_force_unload(unsigned int flags)
L
Linus Torvalds 已提交
553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571
{
	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) {
572
		if (!(*sref->forced = try_force_unload(sref->flags)))
L
Linus Torvalds 已提交
573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656
			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 */
	up(&module_mutex);
	for (;;) {
		DEBUGP("Looking at refcount...\n");
		set_current_state(TASK_UNINTERRUPTIBLE);
		if (module_refcount(mod) == 0)
			break;
		schedule();
	}
	current->state = TASK_RUNNING;
	down(&module_mutex);
}

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';

	if (down_interruptible(&module_mutex) != 0)
		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) {
657
		forced = try_force_unload(flags);
L
Linus Torvalds 已提交
658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777
		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) {
		up(&module_mutex);
		mod->exit();
		down(&module_mutex);
	}
	free_module(mod);

 out:
	up(&module_mutex);
	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)
{
	unsigned long flags;

	spin_lock_irqsave(&modlist_lock, flags);
	if (!kernel_text_address((unsigned long)addr))
		BUG();

	module_put(module_text_address((unsigned long)addr));
	spin_unlock_irqrestore(&modlist_lock, flags);
}
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 */

778 779 780 781 782 783 784 785 786
static struct module_attribute *modinfo_attrs[] = {
	&modinfo_version,
	&modinfo_srcversion,
#ifdef CONFIG_MODULE_UNLOAD
	&refcnt,
#endif
	NULL,
};

L
Linus Torvalds 已提交
787 788 789 790 791 792 793 794
#ifdef CONFIG_OBSOLETE_MODPARM
/* Bounds checking done below */
static int obsparm_copy_string(const char *val, struct kernel_param *kp)
{
	strcpy(kp->arg, val);
	return 0;
}

A
Adrian Bunk 已提交
795
static int set_obsolete(const char *val, struct kernel_param *kp)
L
Linus Torvalds 已提交
796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955
{
	unsigned int min, max;
	unsigned int size, maxsize;
	int dummy;
	char *endp;
	const char *p;
	struct obsolete_modparm *obsparm = kp->arg;

	if (!val) {
		printk(KERN_ERR "Parameter %s needs an argument\n", kp->name);
		return -EINVAL;
	}

	/* type is: [min[-max]]{b,h,i,l,s} */
	p = obsparm->type;
	min = simple_strtol(p, &endp, 10);
	if (endp == obsparm->type)
		min = max = 1;
	else if (*endp == '-') {
		p = endp+1;
		max = simple_strtol(p, &endp, 10);
	} else
		max = min;
	switch (*endp) {
	case 'b':
		return param_array(kp->name, val, min, max, obsparm->addr,
				   1, param_set_byte, &dummy);
	case 'h':
		return param_array(kp->name, val, min, max, obsparm->addr,
				   sizeof(short), param_set_short, &dummy);
	case 'i':
		return param_array(kp->name, val, min, max, obsparm->addr,
				   sizeof(int), param_set_int, &dummy);
	case 'l':
		return param_array(kp->name, val, min, max, obsparm->addr,
				   sizeof(long), param_set_long, &dummy);
	case 's':
		return param_array(kp->name, val, min, max, obsparm->addr,
				   sizeof(char *), param_set_charp, &dummy);

	case 'c':
		/* Undocumented: 1-5c50 means 1-5 strings of up to 49 chars,
		   and the decl is "char xxx[5][50];" */
		p = endp+1;
		maxsize = simple_strtol(p, &endp, 10);
		/* We check lengths here (yes, this is a hack). */
		p = val;
		while (p[size = strcspn(p, ",")]) {
			if (size >= maxsize) 
				goto oversize;
			p += size+1;
		}
		if (size >= maxsize) 
			goto oversize;
		return param_array(kp->name, val, min, max, obsparm->addr,
				   maxsize, obsparm_copy_string, &dummy);
	}
	printk(KERN_ERR "Unknown obsolete parameter type %s\n", obsparm->type);
	return -EINVAL;
 oversize:
	printk(KERN_ERR
	       "Parameter %s doesn't fit in %u chars.\n", kp->name, maxsize);
	return -EINVAL;
}

static int obsolete_params(const char *name,
			   char *args,
			   struct obsolete_modparm obsparm[],
			   unsigned int num,
			   Elf_Shdr *sechdrs,
			   unsigned int symindex,
			   const char *strtab)
{
	struct kernel_param *kp;
	unsigned int i;
	int ret;

	kp = kmalloc(sizeof(kp[0]) * num, GFP_KERNEL);
	if (!kp)
		return -ENOMEM;

	for (i = 0; i < num; i++) {
		char sym_name[128 + sizeof(MODULE_SYMBOL_PREFIX)];

		snprintf(sym_name, sizeof(sym_name), "%s%s",
			 MODULE_SYMBOL_PREFIX, obsparm[i].name);

		kp[i].name = obsparm[i].name;
		kp[i].perm = 000;
		kp[i].set = set_obsolete;
		kp[i].get = NULL;
		obsparm[i].addr
			= (void *)find_local_symbol(sechdrs, symindex, strtab,
						    sym_name);
		if (!obsparm[i].addr) {
			printk("%s: falsely claims to have parameter %s\n",
			       name, obsparm[i].name);
			ret = -EINVAL;
			goto out;
		}
		kp[i].arg = &obsparm[i];
	}

	ret = parse_args(name, args, kp, num, NULL);
 out:
	kfree(kp);
	return ret;
}
#else
static int obsolete_params(const char *name,
			   char *args,
			   struct obsolete_modparm obsparm[],
			   unsigned int num,
			   Elf_Shdr *sechdrs,
			   unsigned int symindex,
			   const char *strtab)
{
	if (num != 0)
		printk(KERN_WARNING "%s: Ignoring obsolete parameters\n",
		       name);
	return 0;
}
#endif /* CONFIG_OBSOLETE_MODPARM */

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);
956
		add_taint(TAINT_FORCED_MODULE);
L
Linus Torvalds 已提交
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 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111
	}
	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 */

1112 1113 1114
static int module_add_modinfo_attrs(struct module *mod)
{
	struct module_attribute *attr;
1115
	struct module_attribute *temp_attr;
1116 1117 1118
	int error = 0;
	int i;

1119 1120 1121 1122 1123 1124 1125
	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;
1126 1127
	for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
		if (!attr->test ||
1128 1129 1130 1131 1132 1133
		    (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;
		}
1134 1135 1136 1137 1138 1139 1140 1141 1142
	}
	return error;
}

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

1143 1144 1145 1146
	for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
		/* pick a field to test for end of list */
		if (!attr->attr.name)
			break;
1147
		sysfs_remove_file(&mod->mkobj.kobj,&attr->attr);
1148 1149
		if (attr->free)
			attr->free(mod);
1150
	}
1151
	kfree(mod->modinfo_attrs);
1152
}
L
Linus Torvalds 已提交
1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173

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;

1174 1175 1176 1177
	err = module_add_modinfo_attrs(mod);
	if (err)
		goto out_unreg;

L
Linus Torvalds 已提交
1178 1179 1180 1181 1182 1183 1184 1185 1186 1187
	return 0;

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

static void mod_kobject_remove(struct module *mod)
{
1188
	module_remove_modinfo_attrs(mod);
L
Linus Torvalds 已提交
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
	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);

	/* 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);

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
/*
 * 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
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 1318 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 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 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
/* 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 inline int license_is_gpl_compatible(const char *license)
{
	return (strcmp(license, "GPL") == 0
		|| strcmp(license, "GPL v2") == 0
		|| strcmp(license, "GPL and additional rights") == 0
		|| strcmp(license, "Dual BSD/GPL") == 0
		|| strcmp(license, "Dual MPL/GPL") == 0);
}

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);
1428
		add_taint(TAINT_PROPRIETARY_MODULE);
L
Linus Torvalds 已提交
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 1460 1461 1462 1463 1464 1465
	}
}

/* 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;
}

1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480
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
1481 1482 1483
#ifdef CONFIG_KALLSYMS
int is_exported(const char *name, const struct module *mod)
{
1484 1485 1486 1487
	if (!mod && lookup_symbol(name, __start___ksymtab, __stop___ksymtab))
		return 1;
	else
		if (lookup_symbol(name, mod->syms, mod->syms + mod->num_syms))
L
Linus Torvalds 已提交
1488
			return 1;
1489 1490
		else
			return 0;
L
Linus Torvalds 已提交
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 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571
}

/* 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;
	unsigned int i, symindex = 0, strindex = 0, setupindex, exindex,
		exportindex, modindex, obsparmindex, infoindex, gplindex,
1572 1573
		crcindex, gplcrcindex, versindex, pcpuindex, gplfutureindex,
		gplfuturecrcindex;
L
Linus Torvalds 已提交
1574 1575 1576 1577 1578
	long arglen;
	struct module *mod;
	long err = 0;
	void *percpu = NULL, *ptr = NULL; /* Stops spurious gcc warning */
	struct exception_table_entry *extable;
1579
	mm_segment_t old_fs;
L
Linus Torvalds 已提交
1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653

	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");
1654
	gplfutureindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_gpl_future");
L
Linus Torvalds 已提交
1655 1656
	crcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab");
	gplcrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_gpl");
1657
	gplfuturecrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_gpl_future");
L
Linus Torvalds 已提交
1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681
	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);

	/* 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

	/* 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) {
1682
		add_taint(TAINT_FORCED_MODULE);
L
Linus Torvalds 已提交
1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707
		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 */
	arglen = strlen_user(uargs);
	if (!arglen) {
		err = -EFAULT;
		goto free_hdr;
	}
	args = kmalloc(arglen, GFP_KERNEL);
	if (!args) {
		err = -ENOMEM;
		goto free_hdr;
	}
	if (copy_from_user(args, uargs, arglen) != 0) {
		err = -EFAULT;
		goto free_mod;
	}

1708 1709 1710
	/* Userspace could have altered the string after the strlen_user() */
	args[arglen - 1] = '\0';

L
Linus Torvalds 已提交
1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725
	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,
1726 1727
					 sechdrs[pcpuindex].sh_addralign,
					 mod->name);
L
Linus Torvalds 已提交
1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 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 1765 1766 1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786 1787
		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"));

1788 1789 1790 1791 1792
	if (strcmp(mod->name, "ndiswrapper") == 0)
		add_taint(TAINT_PROPRIETARY_MODULE);
	if (strcmp(mod->name, "driverloader") == 0)
		add_taint(TAINT_PROPRIETARY_MODULE);

1793 1794 1795
	/* Set up MODINFO_ATTR fields */
	setup_modinfo(mod, sechdrs, infoindex);

L
Linus Torvalds 已提交
1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 1810
	/* 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;
1811 1812 1813 1814 1815
	mod->num_gpl_future_syms = sechdrs[gplfutureindex].sh_size /
					sizeof(*mod->gpl_future_syms);
	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
1816 1817 1818

#ifdef CONFIG_MODVERSIONS
	if ((mod->num_syms && !crcindex) || 
1819 1820
	    (mod->num_gpl_syms && !gplcrcindex) ||
	    (mod->num_gpl_future_syms && !gplfuturecrcindex)) {
L
Linus Torvalds 已提交
1821 1822
		printk(KERN_WARNING "%s: No versions for exported symbols."
		       " Tainting kernel.\n", mod->name);
1823
		add_taint(TAINT_FORCED_MODULE);
L
Linus Torvalds 已提交
1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848
	}
#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;
	}

1849 1850 1851 1852 1853 1854
        /* Find duplicate symbols */
	err = verify_export_symbols(mod);

	if (err < 0)
		goto cleanup;

L
Linus Torvalds 已提交
1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869
  	/* 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;

1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887
	/* 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
1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941
	mod->args = args;
	if (obsparmindex) {
		err = obsolete_params(mod->name, mod->args,
				      (struct obsolete_modparm *)
				      sechdrs[obsparmindex].sh_addr,
				      sechdrs[obsparmindex].sh_size
				      / sizeof(struct obsolete_modparm),
				      sechdrs, symindex,
				      (char *)sechdrs[strindex].sh_addr);
		if (setupindex)
			printk(KERN_WARNING "%s: Ignoring new-style "
			       "parameters in presence of obsolete ones\n",
			       mod->name);
	} else {
		/* 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);
	}
	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);

	/* 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);
1942
	return ERR_PTR(err);
L
Linus Torvalds 已提交
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

 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 */
	if (down_interruptible(&module_mutex) != 0)
		return -EINTR;

	/* Do all the hard work */
	mod = load_module(umod, len, uargs);
	if (IS_ERR(mod)) {
		up(&module_mutex);
		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 */
	up(&module_mutex);

	down(&notify_mutex);
	notifier_call_chain(&module_notify_list, MODULE_STATE_COMING, mod);
	up(&notify_mutex);

	/* 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;
2003
		synchronize_sched();
L
Linus Torvalds 已提交
2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 2041 2042 2043 2044 2045 2046 2047 2048 2049 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 2082 2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102 2103 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
		if (mod->unsafe)
			printk(KERN_ERR "%s: module is now stuck!\n",
			       mod->name);
		else {
			module_put(mod);
			down(&module_mutex);
			free_module(mod);
			up(&module_mutex);
		}
		return ret;
	}

	/* Now it's a first class citizen! */
	down(&module_mutex);
	mod->state = MODULE_STATE_LIVE;
	/* Drop initial reference. */
	module_put(mod);
	module_free(mod, mod->module_init);
	mod->module_init = NULL;
	mod->init_size = 0;
	mod->init_text_size = 0;
	up(&module_mutex);

	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;

	down(&module_mutex);
	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);
			up(&module_mutex);
			return mod;
		}
		symnum -= mod->num_symtab;
	}
	up(&module_mutex);
	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++)
2137 2138
		if (strcmp(name, mod->strtab+mod->symtab[i].st_name) == 0 &&
		    mod->symtab[i].st_info != 'U')
L
Linus Torvalds 已提交
2139 2140 2141 2142 2143 2144 2145 2146 2147 2148 2149 2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 2172 2173 2174 2175 2176 2177 2178 2179 2180 2181 2182 2183 2184 2185 2186 2187 2188 2189 2190 2191 2192 2193 2194 2195 2196 2197 2198 2199 2200 2201 2202 2203 2204 2205 2206 2207 2208 2209 2210 2211 2212 2213 2214 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 2243 2244 2245 2246 2247 2248 2249 2250 2251 2252 2253 2254 2255 2256 2257 2258 2259 2260 2261 2262 2263 2264 2265 2266 2267 2268 2269 2270 2271 2272 2273 2274 2275 2276 2277 2278 2279 2280 2281 2282 2283 2284 2285 2286 2287 2288 2289 2290 2291 2292 2293 2294 2295 2296 2297 2298 2299 2300 2301 2302 2303 2304 2305 2306 2307 2308
			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;

	down(&module_mutex);
	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)
{
	up(&module_mutex);
}

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;
}

/* 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