sem.c 33.0 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 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58
/*
 * linux/ipc/sem.c
 * Copyright (C) 1992 Krishna Balasubramanian
 * Copyright (C) 1995 Eric Schenk, Bruno Haible
 *
 * IMPLEMENTATION NOTES ON CODE REWRITE (Eric Schenk, January 1995):
 * This code underwent a massive rewrite in order to solve some problems
 * with the original code. In particular the original code failed to
 * wake up processes that were waiting for semval to go to 0 if the
 * value went to 0 and was then incremented rapidly enough. In solving
 * this problem I have also modified the implementation so that it
 * processes pending operations in a FIFO manner, thus give a guarantee
 * that processes waiting for a lock on the semaphore won't starve
 * unless another locking process fails to unlock.
 * In addition the following two changes in behavior have been introduced:
 * - The original implementation of semop returned the value
 *   last semaphore element examined on success. This does not
 *   match the manual page specifications, and effectively
 *   allows the user to read the semaphore even if they do not
 *   have read permissions. The implementation now returns 0
 *   on success as stated in the manual page.
 * - There is some confusion over whether the set of undo adjustments
 *   to be performed at exit should be done in an atomic manner.
 *   That is, if we are attempting to decrement the semval should we queue
 *   up and wait until we can do so legally?
 *   The original implementation attempted to do this.
 *   The current implementation does not do so. This is because I don't
 *   think it is the right thing (TM) to do, and because I couldn't
 *   see a clean way to get the old behavior with the new design.
 *   The POSIX standard and SVID should be consulted to determine
 *   what behavior is mandated.
 *
 * Further notes on refinement (Christoph Rohland, December 1998):
 * - The POSIX standard says, that the undo adjustments simply should
 *   redo. So the current implementation is o.K.
 * - The previous code had two flaws:
 *   1) It actively gave the semaphore to the next waiting process
 *      sleeping on the semaphore. Since this process did not have the
 *      cpu this led to many unnecessary context switches and bad
 *      performance. Now we only check which process should be able to
 *      get the semaphore and if this process wants to reduce some
 *      semaphore value we simply wake it up without doing the
 *      operation. So it has to try to get it later. Thus e.g. the
 *      running process may reacquire the semaphore during the current
 *      time slice. If it only waits for zero or increases the semaphore,
 *      we do the operation in advance and wake it up.
 *   2) It did not wake up all zero waiting processes. We try to do
 *      better but only get the semops right which only wait for zero or
 *      increase. If there are decrement operations in the operations
 *      array we do the same as before.
 *
 * With the incarnation of O(1) scheduler, it becomes unnecessary to perform
 * check/retry algorithm for waking up blocked processes as the new scheduler
 * is better at handling thread switch than the old one.
 *
 * /proc/sysvipc/sem support (c) 1999 Dragos Acostachioaie <dragos@iname.com>
 *
 * SMP-threaded, sysctl's added
59
 * (c) 1999 Manfred Spraul <manfred@colorfullife.com>
L
Linus Torvalds 已提交
60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75
 * Enforced range limit on SEM_UNDO
 * (c) 2001 Red Hat Inc <alan@redhat.com>
 * Lockless wakeup
 * (c) 2003 Manfred Spraul <manfred@colorfullife.com>
 */

#include <linux/config.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/init.h>
#include <linux/proc_fs.h>
#include <linux/time.h>
#include <linux/smp_lock.h>
#include <linux/security.h>
#include <linux/syscalls.h>
#include <linux/audit.h>
76
#include <linux/capability.h>
77
#include <linux/seq_file.h>
I
Ingo Molnar 已提交
78 79
#include <linux/mutex.h>

L
Linus Torvalds 已提交
80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95
#include <asm/uaccess.h>
#include "util.h"


#define sem_lock(id)	((struct sem_array*)ipc_lock(&sem_ids,id))
#define sem_unlock(sma)	ipc_unlock(&(sma)->sem_perm)
#define sem_rmid(id)	((struct sem_array*)ipc_rmid(&sem_ids,id))
#define sem_checkid(sma, semid)	\
	ipc_checkid(&sem_ids,&sma->sem_perm,semid)
#define sem_buildid(id, seq) \
	ipc_buildid(&sem_ids, id, seq)
static struct ipc_ids sem_ids;

static int newary (key_t, int, int);
static void freeary (struct sem_array *sma, int id);
#ifdef CONFIG_PROC_FS
96
static int sysvipc_sem_proc_show(struct seq_file *s, void *it);
L
Linus Torvalds 已提交
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
#endif

#define SEMMSL_FAST	256 /* 512 bytes on stack */
#define SEMOPM_FAST	64  /* ~ 372 bytes on stack */

/*
 * linked list protection:
 *	sem_undo.id_next,
 *	sem_array.sem_pending{,last},
 *	sem_array.sem_undo: sem_lock() for read/write
 *	sem_undo.proc_next: only "current" is allowed to read/write that field.
 *	
 */

int sem_ctls[4] = {SEMMSL, SEMMNS, SEMOPM, SEMMNI};
#define sc_semmsl	(sem_ctls[0])
#define sc_semmns	(sem_ctls[1])
#define sc_semopm	(sem_ctls[2])
#define sc_semmni	(sem_ctls[3])

static int used_sems;

void __init sem_init (void)
{
	used_sems = 0;
	ipc_init_ids(&sem_ids,sc_semmni);
123 124 125 126
	ipc_init_proc_interface("sysvipc/sem",
				"       key      semid perms      nsems   uid   gid  cuid  cgid      otime      ctime\n",
				&sem_ids,
				sysvipc_sem_proc_show);
L
Linus Torvalds 已提交
127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143
}

/*
 * Lockless wakeup algorithm:
 * Without the check/retry algorithm a lockless wakeup is possible:
 * - queue.status is initialized to -EINTR before blocking.
 * - wakeup is performed by
 *	* unlinking the queue entry from sma->sem_pending
 *	* setting queue.status to IN_WAKEUP
 *	  This is the notification for the blocked thread that a
 *	  result value is imminent.
 *	* call wake_up_process
 *	* set queue.status to the final value.
 * - the previously blocked thread checks queue.status:
 *   	* if it's IN_WAKEUP, then it must wait until the value changes
 *   	* if it's not -EINTR, then the operation was completed by
 *   	  update_queue. semtimedop can return queue.status without
I
Ingo Molnar 已提交
144
 *   	  performing any operation on the sem array.
L
Linus Torvalds 已提交
145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199
 *   	* otherwise it must acquire the spinlock and check what's up.
 *
 * The two-stage algorithm is necessary to protect against the following
 * races:
 * - if queue.status is set after wake_up_process, then the woken up idle
 *   thread could race forward and try (and fail) to acquire sma->lock
 *   before update_queue had a chance to set queue.status
 * - if queue.status is written before wake_up_process and if the
 *   blocked process is woken up by a signal between writing
 *   queue.status and the wake_up_process, then the woken up
 *   process could return from semtimedop and die by calling
 *   sys_exit before wake_up_process is called. Then wake_up_process
 *   will oops, because the task structure is already invalid.
 *   (yes, this happened on s390 with sysv msg).
 *
 */
#define IN_WAKEUP	1

static int newary (key_t key, int nsems, int semflg)
{
	int id;
	int retval;
	struct sem_array *sma;
	int size;

	if (!nsems)
		return -EINVAL;
	if (used_sems + nsems > sc_semmns)
		return -ENOSPC;

	size = sizeof (*sma) + nsems * sizeof (struct sem);
	sma = ipc_rcu_alloc(size);
	if (!sma) {
		return -ENOMEM;
	}
	memset (sma, 0, size);

	sma->sem_perm.mode = (semflg & S_IRWXUGO);
	sma->sem_perm.key = key;

	sma->sem_perm.security = NULL;
	retval = security_sem_alloc(sma);
	if (retval) {
		ipc_rcu_putref(sma);
		return retval;
	}

	id = ipc_addid(&sem_ids, &sma->sem_perm, sc_semmni);
	if(id == -1) {
		security_sem_free(sma);
		ipc_rcu_putref(sma);
		return -ENOSPC;
	}
	used_sems += nsems;

200
	sma->sem_id = sem_buildid(id, sma->sem_perm.seq);
L
Linus Torvalds 已提交
201 202 203 204 205 206 207 208
	sma->sem_base = (struct sem *) &sma[1];
	/* sma->sem_pending = NULL; */
	sma->sem_pending_last = &sma->sem_pending;
	/* sma->undo = NULL; */
	sma->sem_nsems = nsems;
	sma->sem_ctime = get_seconds();
	sem_unlock(sma);

209
	return sma->sem_id;
L
Linus Torvalds 已提交
210 211 212 213 214 215 216 217 218
}

asmlinkage long sys_semget (key_t key, int nsems, int semflg)
{
	int id, err = -EINVAL;
	struct sem_array *sma;

	if (nsems < 0 || nsems > sc_semmsl)
		return -EINVAL;
I
Ingo Molnar 已提交
219
	mutex_lock(&sem_ids.mutex);
L
Linus Torvalds 已提交
220 221 222 223 224 225 226 227 228 229 230 231
	
	if (key == IPC_PRIVATE) {
		err = newary(key, nsems, semflg);
	} else if ((id = ipc_findkey(&sem_ids, key)) == -1) {  /* key not used */
		if (!(semflg & IPC_CREAT))
			err = -ENOENT;
		else
			err = newary(key, nsems, semflg);
	} else if (semflg & IPC_CREAT && semflg & IPC_EXCL) {
		err = -EEXIST;
	} else {
		sma = sem_lock(id);
232
		BUG_ON(sma==NULL);
L
Linus Torvalds 已提交
233 234 235 236 237 238 239 240 241 242 243 244 245
		if (nsems > sma->sem_nsems)
			err = -EINVAL;
		else if (ipcperms(&sma->sem_perm, semflg))
			err = -EACCES;
		else {
			int semid = sem_buildid(id, sma->sem_perm.seq);
			err = security_sem_associate(sma, semflg);
			if (!err)
				err = semid;
		}
		sem_unlock(sma);
	}

I
Ingo Molnar 已提交
246
	mutex_unlock(&sem_ids.mutex);
L
Linus Torvalds 已提交
247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385
	return err;
}

/* Manage the doubly linked list sma->sem_pending as a FIFO:
 * insert new queue elements at the tail sma->sem_pending_last.
 */
static inline void append_to_queue (struct sem_array * sma,
				    struct sem_queue * q)
{
	*(q->prev = sma->sem_pending_last) = q;
	*(sma->sem_pending_last = &q->next) = NULL;
}

static inline void prepend_to_queue (struct sem_array * sma,
				     struct sem_queue * q)
{
	q->next = sma->sem_pending;
	*(q->prev = &sma->sem_pending) = q;
	if (q->next)
		q->next->prev = &q->next;
	else /* sma->sem_pending_last == &sma->sem_pending */
		sma->sem_pending_last = &q->next;
}

static inline void remove_from_queue (struct sem_array * sma,
				      struct sem_queue * q)
{
	*(q->prev) = q->next;
	if (q->next)
		q->next->prev = q->prev;
	else /* sma->sem_pending_last == &q->next */
		sma->sem_pending_last = q->prev;
	q->prev = NULL; /* mark as removed */
}

/*
 * Determine whether a sequence of semaphore operations would succeed
 * all at once. Return 0 if yes, 1 if need to sleep, else return error code.
 */

static int try_atomic_semop (struct sem_array * sma, struct sembuf * sops,
			     int nsops, struct sem_undo *un, int pid)
{
	int result, sem_op;
	struct sembuf *sop;
	struct sem * curr;

	for (sop = sops; sop < sops + nsops; sop++) {
		curr = sma->sem_base + sop->sem_num;
		sem_op = sop->sem_op;
		result = curr->semval;
  
		if (!sem_op && result)
			goto would_block;

		result += sem_op;
		if (result < 0)
			goto would_block;
		if (result > SEMVMX)
			goto out_of_range;
		if (sop->sem_flg & SEM_UNDO) {
			int undo = un->semadj[sop->sem_num] - sem_op;
			/*
	 		 *	Exceeding the undo range is an error.
			 */
			if (undo < (-SEMAEM - 1) || undo > SEMAEM)
				goto out_of_range;
		}
		curr->semval = result;
	}

	sop--;
	while (sop >= sops) {
		sma->sem_base[sop->sem_num].sempid = pid;
		if (sop->sem_flg & SEM_UNDO)
			un->semadj[sop->sem_num] -= sop->sem_op;
		sop--;
	}
	
	sma->sem_otime = get_seconds();
	return 0;

out_of_range:
	result = -ERANGE;
	goto undo;

would_block:
	if (sop->sem_flg & IPC_NOWAIT)
		result = -EAGAIN;
	else
		result = 1;

undo:
	sop--;
	while (sop >= sops) {
		sma->sem_base[sop->sem_num].semval -= sop->sem_op;
		sop--;
	}

	return result;
}

/* Go through the pending queue for the indicated semaphore
 * looking for tasks that can be completed.
 */
static void update_queue (struct sem_array * sma)
{
	int error;
	struct sem_queue * q;

	q = sma->sem_pending;
	while(q) {
		error = try_atomic_semop(sma, q->sops, q->nsops,
					 q->undo, q->pid);

		/* Does q->sleeper still need to sleep? */
		if (error <= 0) {
			struct sem_queue *n;
			remove_from_queue(sma,q);
			q->status = IN_WAKEUP;
			/*
			 * Continue scanning. The next operation
			 * that must be checked depends on the type of the
			 * completed operation:
			 * - if the operation modified the array, then
			 *   restart from the head of the queue and
			 *   check for threads that might be waiting
			 *   for semaphore values to become 0.
			 * - if the operation didn't modify the array,
			 *   then just continue.
			 */
			if (q->alter)
				n = sma->sem_pending;
			else
				n = q->next;
			wake_up_process(q->sleeper);
			/* hands-off: q will disappear immediately after
			 * writing q->status.
			 */
L
Linus Torvalds 已提交
386
			smp_wmb();
L
Linus Torvalds 已提交
387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440
			q->status = error;
			q = n;
		} else {
			q = q->next;
		}
	}
}

/* The following counts are associated to each semaphore:
 *   semncnt        number of tasks waiting on semval being nonzero
 *   semzcnt        number of tasks waiting on semval being zero
 * This model assumes that a task waits on exactly one semaphore.
 * Since semaphore operations are to be performed atomically, tasks actually
 * wait on a whole sequence of semaphores simultaneously.
 * The counts we return here are a rough approximation, but still
 * warrant that semncnt+semzcnt>0 if the task is on the pending queue.
 */
static int count_semncnt (struct sem_array * sma, ushort semnum)
{
	int semncnt;
	struct sem_queue * q;

	semncnt = 0;
	for (q = sma->sem_pending; q; q = q->next) {
		struct sembuf * sops = q->sops;
		int nsops = q->nsops;
		int i;
		for (i = 0; i < nsops; i++)
			if (sops[i].sem_num == semnum
			    && (sops[i].sem_op < 0)
			    && !(sops[i].sem_flg & IPC_NOWAIT))
				semncnt++;
	}
	return semncnt;
}
static int count_semzcnt (struct sem_array * sma, ushort semnum)
{
	int semzcnt;
	struct sem_queue * q;

	semzcnt = 0;
	for (q = sma->sem_pending; q; q = q->next) {
		struct sembuf * sops = q->sops;
		int nsops = q->nsops;
		int i;
		for (i = 0; i < nsops; i++)
			if (sops[i].sem_num == semnum
			    && (sops[i].sem_op == 0)
			    && !(sops[i].sem_flg & IPC_NOWAIT))
				semzcnt++;
	}
	return semzcnt;
}

I
Ingo Molnar 已提交
441 442
/* Free a semaphore set. freeary() is called with sem_ids.mutex locked and
 * the spinlock for this semaphore set hold. sem_ids.mutex remains locked
L
Linus Torvalds 已提交
443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466
 * on exit.
 */
static void freeary (struct sem_array *sma, int id)
{
	struct sem_undo *un;
	struct sem_queue *q;
	int size;

	/* Invalidate the existing undo structures for this semaphore set.
	 * (They will be freed without any further action in exit_sem()
	 * or during the next semop.)
	 */
	for (un = sma->undo; un; un = un->id_next)
		un->semid = -1;

	/* Wake up all pending processes and let them fail with EIDRM. */
	q = sma->sem_pending;
	while(q) {
		struct sem_queue *n;
		/* lazy remove_from_queue: we are killing the whole queue */
		q->prev = NULL;
		n = q->next;
		q->status = IN_WAKEUP;
		wake_up_process(q->sleeper); /* doesn't sleep */
467
		smp_wmb();
L
Linus Torvalds 已提交
468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528
		q->status = -EIDRM;	/* hands-off q */
		q = n;
	}

	/* Remove the semaphore set from the ID array*/
	sma = sem_rmid(id);
	sem_unlock(sma);

	used_sems -= sma->sem_nsems;
	size = sizeof (*sma) + sma->sem_nsems * sizeof (struct sem);
	security_sem_free(sma);
	ipc_rcu_putref(sma);
}

static unsigned long copy_semid_to_user(void __user *buf, struct semid64_ds *in, int version)
{
	switch(version) {
	case IPC_64:
		return copy_to_user(buf, in, sizeof(*in));
	case IPC_OLD:
	    {
		struct semid_ds out;

		ipc64_perm_to_ipc_perm(&in->sem_perm, &out.sem_perm);

		out.sem_otime	= in->sem_otime;
		out.sem_ctime	= in->sem_ctime;
		out.sem_nsems	= in->sem_nsems;

		return copy_to_user(buf, &out, sizeof(out));
	    }
	default:
		return -EINVAL;
	}
}

static int semctl_nolock(int semid, int semnum, int cmd, int version, union semun arg)
{
	int err = -EINVAL;
	struct sem_array *sma;

	switch(cmd) {
	case IPC_INFO:
	case SEM_INFO:
	{
		struct seminfo seminfo;
		int max_id;

		err = security_sem_semctl(NULL, cmd);
		if (err)
			return err;
		
		memset(&seminfo,0,sizeof(seminfo));
		seminfo.semmni = sc_semmni;
		seminfo.semmns = sc_semmns;
		seminfo.semmsl = sc_semmsl;
		seminfo.semopm = sc_semopm;
		seminfo.semvmx = SEMVMX;
		seminfo.semmnu = SEMMNU;
		seminfo.semmap = SEMMAP;
		seminfo.semume = SEMUME;
I
Ingo Molnar 已提交
529
		mutex_lock(&sem_ids.mutex);
L
Linus Torvalds 已提交
530 531 532 533 534 535 536 537
		if (cmd == SEM_INFO) {
			seminfo.semusz = sem_ids.in_use;
			seminfo.semaem = used_sems;
		} else {
			seminfo.semusz = SEMUSZ;
			seminfo.semaem = SEMAEM;
		}
		max_id = sem_ids.max_id;
I
Ingo Molnar 已提交
538
		mutex_unlock(&sem_ids.mutex);
L
Linus Torvalds 已提交
539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838
		if (copy_to_user (arg.__buf, &seminfo, sizeof(struct seminfo))) 
			return -EFAULT;
		return (max_id < 0) ? 0: max_id;
	}
	case SEM_STAT:
	{
		struct semid64_ds tbuf;
		int id;

		if(semid >= sem_ids.entries->size)
			return -EINVAL;

		memset(&tbuf,0,sizeof(tbuf));

		sma = sem_lock(semid);
		if(sma == NULL)
			return -EINVAL;

		err = -EACCES;
		if (ipcperms (&sma->sem_perm, S_IRUGO))
			goto out_unlock;

		err = security_sem_semctl(sma, cmd);
		if (err)
			goto out_unlock;

		id = sem_buildid(semid, sma->sem_perm.seq);

		kernel_to_ipc64_perm(&sma->sem_perm, &tbuf.sem_perm);
		tbuf.sem_otime  = sma->sem_otime;
		tbuf.sem_ctime  = sma->sem_ctime;
		tbuf.sem_nsems  = sma->sem_nsems;
		sem_unlock(sma);
		if (copy_semid_to_user (arg.buf, &tbuf, version))
			return -EFAULT;
		return id;
	}
	default:
		return -EINVAL;
	}
	return err;
out_unlock:
	sem_unlock(sma);
	return err;
}

static int semctl_main(int semid, int semnum, int cmd, int version, union semun arg)
{
	struct sem_array *sma;
	struct sem* curr;
	int err;
	ushort fast_sem_io[SEMMSL_FAST];
	ushort* sem_io = fast_sem_io;
	int nsems;

	sma = sem_lock(semid);
	if(sma==NULL)
		return -EINVAL;

	nsems = sma->sem_nsems;

	err=-EIDRM;
	if (sem_checkid(sma,semid))
		goto out_unlock;

	err = -EACCES;
	if (ipcperms (&sma->sem_perm, (cmd==SETVAL||cmd==SETALL)?S_IWUGO:S_IRUGO))
		goto out_unlock;

	err = security_sem_semctl(sma, cmd);
	if (err)
		goto out_unlock;

	err = -EACCES;
	switch (cmd) {
	case GETALL:
	{
		ushort __user *array = arg.array;
		int i;

		if(nsems > SEMMSL_FAST) {
			ipc_rcu_getref(sma);
			sem_unlock(sma);			

			sem_io = ipc_alloc(sizeof(ushort)*nsems);
			if(sem_io == NULL) {
				ipc_lock_by_ptr(&sma->sem_perm);
				ipc_rcu_putref(sma);
				sem_unlock(sma);
				return -ENOMEM;
			}

			ipc_lock_by_ptr(&sma->sem_perm);
			ipc_rcu_putref(sma);
			if (sma->sem_perm.deleted) {
				sem_unlock(sma);
				err = -EIDRM;
				goto out_free;
			}
		}

		for (i = 0; i < sma->sem_nsems; i++)
			sem_io[i] = sma->sem_base[i].semval;
		sem_unlock(sma);
		err = 0;
		if(copy_to_user(array, sem_io, nsems*sizeof(ushort)))
			err = -EFAULT;
		goto out_free;
	}
	case SETALL:
	{
		int i;
		struct sem_undo *un;

		ipc_rcu_getref(sma);
		sem_unlock(sma);

		if(nsems > SEMMSL_FAST) {
			sem_io = ipc_alloc(sizeof(ushort)*nsems);
			if(sem_io == NULL) {
				ipc_lock_by_ptr(&sma->sem_perm);
				ipc_rcu_putref(sma);
				sem_unlock(sma);
				return -ENOMEM;
			}
		}

		if (copy_from_user (sem_io, arg.array, nsems*sizeof(ushort))) {
			ipc_lock_by_ptr(&sma->sem_perm);
			ipc_rcu_putref(sma);
			sem_unlock(sma);
			err = -EFAULT;
			goto out_free;
		}

		for (i = 0; i < nsems; i++) {
			if (sem_io[i] > SEMVMX) {
				ipc_lock_by_ptr(&sma->sem_perm);
				ipc_rcu_putref(sma);
				sem_unlock(sma);
				err = -ERANGE;
				goto out_free;
			}
		}
		ipc_lock_by_ptr(&sma->sem_perm);
		ipc_rcu_putref(sma);
		if (sma->sem_perm.deleted) {
			sem_unlock(sma);
			err = -EIDRM;
			goto out_free;
		}

		for (i = 0; i < nsems; i++)
			sma->sem_base[i].semval = sem_io[i];
		for (un = sma->undo; un; un = un->id_next)
			for (i = 0; i < nsems; i++)
				un->semadj[i] = 0;
		sma->sem_ctime = get_seconds();
		/* maybe some queued-up processes were waiting for this */
		update_queue(sma);
		err = 0;
		goto out_unlock;
	}
	case IPC_STAT:
	{
		struct semid64_ds tbuf;
		memset(&tbuf,0,sizeof(tbuf));
		kernel_to_ipc64_perm(&sma->sem_perm, &tbuf.sem_perm);
		tbuf.sem_otime  = sma->sem_otime;
		tbuf.sem_ctime  = sma->sem_ctime;
		tbuf.sem_nsems  = sma->sem_nsems;
		sem_unlock(sma);
		if (copy_semid_to_user (arg.buf, &tbuf, version))
			return -EFAULT;
		return 0;
	}
	/* GETVAL, GETPID, GETNCTN, GETZCNT, SETVAL: fall-through */
	}
	err = -EINVAL;
	if(semnum < 0 || semnum >= nsems)
		goto out_unlock;

	curr = &sma->sem_base[semnum];

	switch (cmd) {
	case GETVAL:
		err = curr->semval;
		goto out_unlock;
	case GETPID:
		err = curr->sempid;
		goto out_unlock;
	case GETNCNT:
		err = count_semncnt(sma,semnum);
		goto out_unlock;
	case GETZCNT:
		err = count_semzcnt(sma,semnum);
		goto out_unlock;
	case SETVAL:
	{
		int val = arg.val;
		struct sem_undo *un;
		err = -ERANGE;
		if (val > SEMVMX || val < 0)
			goto out_unlock;

		for (un = sma->undo; un; un = un->id_next)
			un->semadj[semnum] = 0;
		curr->semval = val;
		curr->sempid = current->tgid;
		sma->sem_ctime = get_seconds();
		/* maybe some queued-up processes were waiting for this */
		update_queue(sma);
		err = 0;
		goto out_unlock;
	}
	}
out_unlock:
	sem_unlock(sma);
out_free:
	if(sem_io != fast_sem_io)
		ipc_free(sem_io, sizeof(ushort)*nsems);
	return err;
}

struct sem_setbuf {
	uid_t	uid;
	gid_t	gid;
	mode_t	mode;
};

static inline unsigned long copy_semid_from_user(struct sem_setbuf *out, void __user *buf, int version)
{
	switch(version) {
	case IPC_64:
	    {
		struct semid64_ds tbuf;

		if(copy_from_user(&tbuf, buf, sizeof(tbuf)))
			return -EFAULT;

		out->uid	= tbuf.sem_perm.uid;
		out->gid	= tbuf.sem_perm.gid;
		out->mode	= tbuf.sem_perm.mode;

		return 0;
	    }
	case IPC_OLD:
	    {
		struct semid_ds tbuf_old;

		if(copy_from_user(&tbuf_old, buf, sizeof(tbuf_old)))
			return -EFAULT;

		out->uid	= tbuf_old.sem_perm.uid;
		out->gid	= tbuf_old.sem_perm.gid;
		out->mode	= tbuf_old.sem_perm.mode;

		return 0;
	    }
	default:
		return -EINVAL;
	}
}

static int semctl_down(int semid, int semnum, int cmd, int version, union semun arg)
{
	struct sem_array *sma;
	int err;
	struct sem_setbuf setbuf;
	struct kern_ipc_perm *ipcp;

	if(cmd == IPC_SET) {
		if(copy_semid_from_user (&setbuf, arg.buf, version))
			return -EFAULT;
	}
	sma = sem_lock(semid);
	if(sma==NULL)
		return -EINVAL;

	if (sem_checkid(sma,semid)) {
		err=-EIDRM;
		goto out_unlock;
	}	
	ipcp = &sma->sem_perm;
	if (current->euid != ipcp->cuid && 
	    current->euid != ipcp->uid && !capable(CAP_SYS_ADMIN)) {
	    	err=-EPERM;
		goto out_unlock;
	}

	err = security_sem_semctl(sma, cmd);
	if (err)
		goto out_unlock;

	switch(cmd){
	case IPC_RMID:
		freeary(sma, semid);
		err = 0;
		break;
	case IPC_SET:
839 840
		if ((err = audit_ipc_perms(0, setbuf.uid, setbuf.gid, setbuf.mode, ipcp)))
			goto out_unlock;
L
Linus Torvalds 已提交
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
		ipcp->uid = setbuf.uid;
		ipcp->gid = setbuf.gid;
		ipcp->mode = (ipcp->mode & ~S_IRWXUGO)
				| (setbuf.mode & S_IRWXUGO);
		sma->sem_ctime = get_seconds();
		sem_unlock(sma);
		err = 0;
		break;
	default:
		sem_unlock(sma);
		err = -EINVAL;
		break;
	}
	return err;

out_unlock:
	sem_unlock(sma);
	return err;
}

asmlinkage long sys_semctl (int semid, int semnum, int cmd, union semun arg)
{
	int err = -EINVAL;
	int version;

	if (semid < 0)
		return -EINVAL;

	version = ipc_parse_version(&cmd);

	switch(cmd) {
	case IPC_INFO:
	case SEM_INFO:
	case SEM_STAT:
		err = semctl_nolock(semid,semnum,cmd,version,arg);
		return err;
	case GETALL:
	case GETVAL:
	case GETPID:
	case GETNCNT:
	case GETZCNT:
	case IPC_STAT:
	case SETVAL:
	case SETALL:
		err = semctl_main(semid,semnum,cmd,version,arg);
		return err;
	case IPC_RMID:
	case IPC_SET:
I
Ingo Molnar 已提交
889
		mutex_lock(&sem_ids.mutex);
L
Linus Torvalds 已提交
890
		err = semctl_down(semid,semnum,cmd,version,arg);
I
Ingo Molnar 已提交
891
		mutex_unlock(&sem_ids.mutex);
L
Linus Torvalds 已提交
892 893 894 895 896 897 898 899 900 901 902
		return err;
	default:
		return -EINVAL;
	}
}

static inline void lock_semundo(void)
{
	struct sem_undo_list *undo_list;

	undo_list = current->sysvsem.undo_list;
I
Ingo Molnar 已提交
903
	if (undo_list)
L
Linus Torvalds 已提交
904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922
		spin_lock(&undo_list->lock);
}

/* This code has an interaction with copy_semundo().
 * Consider; two tasks are sharing the undo_list. task1
 * acquires the undo_list lock in lock_semundo().  If task2 now
 * exits before task1 releases the lock (by calling
 * unlock_semundo()), then task1 will never call spin_unlock().
 * This leave the sem_undo_list in a locked state.  If task1 now creats task3
 * and once again shares the sem_undo_list, the sem_undo_list will still be
 * locked, and future SEM_UNDO operations will deadlock.  This case is
 * dealt with in copy_semundo() by having it reinitialize the spin lock when 
 * the refcnt goes from 1 to 2.
 */
static inline void unlock_semundo(void)
{
	struct sem_undo_list *undo_list;

	undo_list = current->sysvsem.undo_list;
I
Ingo Molnar 已提交
923
	if (undo_list)
L
Linus Torvalds 已提交
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
		spin_unlock(&undo_list->lock);
}


/* If the task doesn't already have a undo_list, then allocate one
 * here.  We guarantee there is only one thread using this undo list,
 * and current is THE ONE
 *
 * If this allocation and assignment succeeds, but later
 * portions of this code fail, there is no need to free the sem_undo_list.
 * Just let it stay associated with the task, and it'll be freed later
 * at exit time.
 *
 * This can block, so callers must hold no locks.
 */
static inline int get_undo_list(struct sem_undo_list **undo_listp)
{
	struct sem_undo_list *undo_list;
	int size;

	undo_list = current->sysvsem.undo_list;
	if (!undo_list) {
		size = sizeof(struct sem_undo_list);
		undo_list = (struct sem_undo_list *) kmalloc(size, GFP_KERNEL);
		if (undo_list == NULL)
			return -ENOMEM;
		memset(undo_list, 0, size);
I
Ingo Molnar 已提交
951
		spin_lock_init(&undo_list->lock);
L
Linus Torvalds 已提交
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 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
		atomic_set(&undo_list->refcnt, 1);
		current->sysvsem.undo_list = undo_list;
	}
	*undo_listp = undo_list;
	return 0;
}

static struct sem_undo *lookup_undo(struct sem_undo_list *ulp, int semid)
{
	struct sem_undo **last, *un;

	last = &ulp->proc_list;
	un = *last;
	while(un != NULL) {
		if(un->semid==semid)
			break;
		if(un->semid==-1) {
			*last=un->proc_next;
			kfree(un);
		} else {
			last=&un->proc_next;
		}
		un=*last;
	}
	return un;
}

static struct sem_undo *find_undo(int semid)
{
	struct sem_array *sma;
	struct sem_undo_list *ulp;
	struct sem_undo *un, *new;
	int nsems;
	int error;

	error = get_undo_list(&ulp);
	if (error)
		return ERR_PTR(error);

	lock_semundo();
	un = lookup_undo(ulp, semid);
	unlock_semundo();
	if (likely(un!=NULL))
		goto out;

	/* no undo structure around - allocate one. */
	sma = sem_lock(semid);
	un = ERR_PTR(-EINVAL);
	if(sma==NULL)
		goto out;
	un = ERR_PTR(-EIDRM);
	if (sem_checkid(sma,semid)) {
		sem_unlock(sma);
		goto out;
	}
	nsems = sma->sem_nsems;
	ipc_rcu_getref(sma);
	sem_unlock(sma);

	new = (struct sem_undo *) kmalloc(sizeof(struct sem_undo) + sizeof(short)*nsems, GFP_KERNEL);
	if (!new) {
		ipc_lock_by_ptr(&sma->sem_perm);
		ipc_rcu_putref(sma);
		sem_unlock(sma);
		return ERR_PTR(-ENOMEM);
	}
	memset(new, 0, sizeof(struct sem_undo) + sizeof(short)*nsems);
	new->semadj = (short *) &new[1];
	new->semid = semid;

	lock_semundo();
	un = lookup_undo(ulp, semid);
	if (un) {
		unlock_semundo();
		kfree(new);
		ipc_lock_by_ptr(&sma->sem_perm);
		ipc_rcu_putref(sma);
		sem_unlock(sma);
		goto out;
	}
	ipc_lock_by_ptr(&sma->sem_perm);
	ipc_rcu_putref(sma);
	if (sma->sem_perm.deleted) {
		sem_unlock(sma);
		unlock_semundo();
		kfree(new);
		un = ERR_PTR(-EIDRM);
		goto out;
	}
	new->proc_next = ulp->proc_list;
	ulp->proc_list = new;
	new->id_next = sma->undo;
	sma->undo = new;
	sem_unlock(sma);
	un = new;
	unlock_semundo();
out:
	return un;
}

asmlinkage long sys_semtimedop(int semid, struct sembuf __user *tsops,
			unsigned nsops, const struct timespec __user *timeout)
{
	int error = -EINVAL;
	struct sem_array *sma;
	struct sembuf fast_sops[SEMOPM_FAST];
	struct sembuf* sops = fast_sops, *sop;
	struct sem_undo *un;
1060
	int undos = 0, alter = 0, max;
L
Linus Torvalds 已提交
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
	struct sem_queue queue;
	unsigned long jiffies_left = 0;

	if (nsops < 1 || semid < 0)
		return -EINVAL;
	if (nsops > sc_semopm)
		return -E2BIG;
	if(nsops > SEMOPM_FAST) {
		sops = kmalloc(sizeof(*sops)*nsops,GFP_KERNEL);
		if(sops==NULL)
			return -ENOMEM;
	}
	if (copy_from_user (sops, tsops, nsops * sizeof(*tsops))) {
		error=-EFAULT;
		goto out_free;
	}
	if (timeout) {
		struct timespec _timeout;
		if (copy_from_user(&_timeout, timeout, sizeof(*timeout))) {
			error = -EFAULT;
			goto out_free;
		}
		if (_timeout.tv_sec < 0 || _timeout.tv_nsec < 0 ||
			_timeout.tv_nsec >= 1000000000L) {
			error = -EINVAL;
			goto out_free;
		}
		jiffies_left = timespec_to_jiffies(&_timeout);
	}
	max = 0;
	for (sop = sops; sop < sops + nsops; sop++) {
		if (sop->sem_num >= max)
			max = sop->sem_num;
		if (sop->sem_flg & SEM_UNDO)
1095 1096
			undos = 1;
		if (sop->sem_op != 0)
L
Linus Torvalds 已提交
1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184
			alter = 1;
	}

retry_undos:
	if (undos) {
		un = find_undo(semid);
		if (IS_ERR(un)) {
			error = PTR_ERR(un);
			goto out_free;
		}
	} else
		un = NULL;

	sma = sem_lock(semid);
	error=-EINVAL;
	if(sma==NULL)
		goto out_free;
	error = -EIDRM;
	if (sem_checkid(sma,semid))
		goto out_unlock_free;
	/*
	 * semid identifies are not unique - find_undo may have
	 * allocated an undo structure, it was invalidated by an RMID
	 * and now a new array with received the same id. Check and retry.
	 */
	if (un && un->semid == -1) {
		sem_unlock(sma);
		goto retry_undos;
	}
	error = -EFBIG;
	if (max >= sma->sem_nsems)
		goto out_unlock_free;

	error = -EACCES;
	if (ipcperms(&sma->sem_perm, alter ? S_IWUGO : S_IRUGO))
		goto out_unlock_free;

	error = security_sem_semop(sma, sops, nsops, alter);
	if (error)
		goto out_unlock_free;

	error = try_atomic_semop (sma, sops, nsops, un, current->tgid);
	if (error <= 0) {
		if (alter && error == 0)
			update_queue (sma);
		goto out_unlock_free;
	}

	/* We need to sleep on this operation, so we put the current
	 * task into the pending queue and go to sleep.
	 */
		
	queue.sma = sma;
	queue.sops = sops;
	queue.nsops = nsops;
	queue.undo = un;
	queue.pid = current->tgid;
	queue.id = semid;
	queue.alter = alter;
	if (alter)
		append_to_queue(sma ,&queue);
	else
		prepend_to_queue(sma ,&queue);

	queue.status = -EINTR;
	queue.sleeper = current;
	current->state = TASK_INTERRUPTIBLE;
	sem_unlock(sma);

	if (timeout)
		jiffies_left = schedule_timeout(jiffies_left);
	else
		schedule();

	error = queue.status;
	while(unlikely(error == IN_WAKEUP)) {
		cpu_relax();
		error = queue.status;
	}

	if (error != -EINTR) {
		/* fast path: update_queue already obtained all requested
		 * resources */
		goto out_free;
	}

	sma = sem_lock(semid);
	if(sma==NULL) {
1185
		BUG_ON(queue.prev != NULL);
L
Linus Torvalds 已提交
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
		error = -EIDRM;
		goto out_free;
	}

	/*
	 * If queue.status != -EINTR we are woken up by another process
	 */
	error = queue.status;
	if (error != -EINTR) {
		goto out_unlock_free;
	}

	/*
	 * If an interrupt occurred we have to clean up the queue
	 */
	if (timeout && jiffies_left == 0)
		error = -EAGAIN;
	remove_from_queue(sma,&queue);
	goto out_unlock_free;

out_unlock_free:
	sem_unlock(sma);
out_free:
	if(sops != fast_sops)
		kfree(sops);
	return error;
}

asmlinkage long sys_semop (int semid, struct sembuf __user *tsops, unsigned nsops)
{
	return sys_semtimedop(semid, tsops, nsops, NULL);
}

/* If CLONE_SYSVSEM is set, establish sharing of SEM_UNDO state between
 * parent and child tasks.
 *
 * See the notes above unlock_semundo() regarding the spin_lock_init()
 * in this code.  Initialize the undo_list->lock here instead of get_undo_list()
 * because of the reasoning in the comment above unlock_semundo.
 */

int copy_semundo(unsigned long clone_flags, struct task_struct *tsk)
{
	struct sem_undo_list *undo_list;
	int error;

	if (clone_flags & CLONE_SYSVSEM) {
		error = get_undo_list(&undo_list);
		if (error)
			return error;
		atomic_inc(&undo_list->refcnt);
		tsk->sysvsem.undo_list = undo_list;
	} else 
		tsk->sysvsem.undo_list = NULL;

	return 0;
}

/*
 * add semadj values to semaphores, free undo structures.
 * undo structures are not freed when semaphore arrays are destroyed
 * so some of them may be out of date.
 * IMPLEMENTATION NOTE: There is some confusion over whether the
 * set of adjustments that needs to be done should be done in an atomic
 * manner or not. That is, if we are attempting to decrement the semval
 * should we queue up and wait until we can do so legally?
 * The original implementation attempted to do this (queue and wait).
 * The current implementation does not do so. The POSIX standard
 * and SVID should be consulted to determine what behavior is mandated.
 */
void exit_sem(struct task_struct *tsk)
{
	struct sem_undo_list *undo_list;
	struct sem_undo *u, **up;

	undo_list = tsk->sysvsem.undo_list;
	if (!undo_list)
		return;

	if (!atomic_dec_and_test(&undo_list->refcnt))
		return;

	/* There's no need to hold the semundo list lock, as current
         * is the last task exiting for this undo list.
	 */
	for (up = &undo_list->proc_list; (u = *up); *up = u->proc_next, kfree(u)) {
		struct sem_array *sma;
		int nsems, i;
		struct sem_undo *un, **unp;
		int semid;
	       
		semid = u->semid;

		if(semid == -1)
			continue;
		sma = sem_lock(semid);
		if (sma == NULL)
			continue;

		if (u->semid == -1)
			goto next_entry;

		BUG_ON(sem_checkid(sma,u->semid));

		/* remove u from the sma->undo list */
		for (unp = &sma->undo; (un = *unp); unp = &un->id_next) {
			if (u == un)
				goto found;
		}
		printk ("exit_sem undo list error id=%d\n", u->semid);
		goto next_entry;
found:
		*unp = un->id_next;
		/* perform adjustments registered in u */
		nsems = sma->sem_nsems;
		for (i = 0; i < nsems; i++) {
I
Ingo Molnar 已提交
1302
			struct sem * semaphore = &sma->sem_base[i];
L
Linus Torvalds 已提交
1303
			if (u->semadj[i]) {
I
Ingo Molnar 已提交
1304
				semaphore->semval += u->semadj[i];
L
Linus Torvalds 已提交
1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317
				/*
				 * Range checks of the new semaphore value,
				 * not defined by sus:
				 * - Some unices ignore the undo entirely
				 *   (e.g. HP UX 11i 11.22, Tru64 V5.1)
				 * - some cap the value (e.g. FreeBSD caps
				 *   at 0, but doesn't enforce SEMVMX)
				 *
				 * Linux caps the semaphore value, both at 0
				 * and at SEMVMX.
				 *
				 * 	Manfred <manfred@colorfullife.com>
				 */
I
Ingo Molnar 已提交
1318 1319 1320 1321 1322
				if (semaphore->semval < 0)
					semaphore->semval = 0;
				if (semaphore->semval > SEMVMX)
					semaphore->semval = SEMVMX;
				semaphore->sempid = current->tgid;
L
Linus Torvalds 已提交
1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334
			}
		}
		sma->sem_otime = get_seconds();
		/* maybe some queued-up processes were waiting for this */
		update_queue(sma);
next_entry:
		sem_unlock(sma);
	}
	kfree(undo_list);
}

#ifdef CONFIG_PROC_FS
1335
static int sysvipc_sem_proc_show(struct seq_file *s, void *it)
L
Linus Torvalds 已提交
1336
{
1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350
	struct sem_array *sma = it;

	return seq_printf(s,
			  "%10d %10d  %4o %10lu %5u %5u %5u %5u %10lu %10lu\n",
			  sma->sem_perm.key,
			  sma->sem_id,
			  sma->sem_perm.mode,
			  sma->sem_nsems,
			  sma->sem_perm.uid,
			  sma->sem_perm.gid,
			  sma->sem_perm.cuid,
			  sma->sem_perm.cgid,
			  sma->sem_otime,
			  sma->sem_ctime);
L
Linus Torvalds 已提交
1351 1352
}
#endif