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linux_ipc.c revision 1.31.4.6
      1 /*	$NetBSD: linux_ipc.c,v 1.31.4.6 2008/02/04 09:23:06 yamt Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1995, 1998 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Frank van der Linden and Eric Haszlakiewicz.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  * 3. All advertising materials mentioning features or use of this software
     19  *    must display the following acknowledgement:
     20  *	This product includes software developed by the NetBSD
     21  *	Foundation, Inc. and its contributors.
     22  * 4. Neither the name of The NetBSD Foundation nor the names of its
     23  *    contributors may be used to endorse or promote products derived
     24  *    from this software without specific prior written permission.
     25  *
     26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     36  * POSSIBILITY OF SUCH DAMAGE.
     37  */
     38 
     39 #include <sys/cdefs.h>
     40 __KERNEL_RCSID(0, "$NetBSD: linux_ipc.c,v 1.31.4.6 2008/02/04 09:23:06 yamt Exp $");
     41 
     42 #if defined(_KERNEL_OPT)
     43 #include "opt_sysv.h"
     44 #endif
     45 
     46 #include <sys/param.h>
     47 #include <sys/shm.h>
     48 #include <sys/sem.h>
     49 #include <sys/msg.h>
     50 #include <sys/proc.h>
     51 #include <sys/systm.h>
     52 #include <sys/vnode.h>
     53 
     54 #include <sys/mount.h>
     55 #include <sys/syscallargs.h>
     56 
     57 #include <compat/linux/common/linux_types.h>
     58 #include <compat/linux/common/linux_signal.h>
     59 #include <compat/linux/common/linux_util.h>
     60 #include <compat/linux/common/linux_ipc.h>
     61 #include <compat/linux/common/linux_msg.h>
     62 #include <compat/linux/common/linux_shm.h>
     63 #include <compat/linux/common/linux_sem.h>
     64 
     65 #include <compat/linux/linux_syscallargs.h>
     66 #include <compat/linux/linux_syscall.h>
     67 
     68 #include <compat/linux/common/linux_ipccall.h>
     69 #include <compat/linux/common/linux_machdep.h>
     70 
     71 /*
     72  * Note: Not all linux architechtures have explicit versions
     73  *	of the SYSV* syscalls.  On the ones that don't
     74  *	we pretend that they are defined anyway.  *_args and
     75  *	prototypes are defined in individual headers;
     76  *	syscalls.master lists those syscalls as NOARGS.
     77  *
     78  *	The functions in multiarch are the ones that just need
     79  *	the arguments shuffled around and then use the
     80  *	normal NetBSD syscall.
     81  *
     82  * Function in multiarch:
     83  *	linux_sys_ipc		: linux_ipccall.c
     84  *	liunx_semop		: linux_ipccall.c
     85  *	linux_semget		: linux_ipccall.c
     86  *	linux_msgsnd		: linux_ipccall.c
     87  *	linux_msgrcv		: linux_ipccall.c
     88  *	linux_msgget		: linux_ipccall.c
     89  *	linux_shmdt		: linux_ipccall.c
     90  *	linux_shmget		: linux_ipccall.c
     91  */
     92 
     93 #if defined (SYSVSEM) || defined(SYSVSHM) || defined(SYSVMSG)
     94 /*
     95  * Convert between Linux and NetBSD ipc_perm structures. Only the
     96  * order of the fields is different.
     97  */
     98 void
     99 linux_to_bsd_ipc_perm(struct linux_ipc_perm *lpp, struct ipc_perm *bpp)
    100 {
    101 
    102 	bpp->_key = lpp->l_key;
    103 	bpp->uid = lpp->l_uid;
    104 	bpp->gid = lpp->l_gid;
    105 	bpp->cuid = lpp->l_cuid;
    106 	bpp->cgid = lpp->l_cgid;
    107 	bpp->mode = lpp->l_mode;
    108 	bpp->_seq = lpp->l_seq;
    109 }
    110 
    111 void
    112 linux_to_bsd_ipc64_perm(struct linux_ipc64_perm *lpp, struct ipc_perm *bpp)
    113 {
    114 	bpp->_key = lpp->l_key;
    115 	bpp->uid = lpp->l_uid;
    116 	bpp->gid = lpp->l_gid;
    117 	bpp->cuid = lpp->l_cuid;
    118 	bpp->cgid = lpp->l_cgid;
    119 	bpp->mode = lpp->l_mode;
    120 	bpp->_seq = lpp->l_seq;
    121 }
    122 
    123 void
    124 bsd_to_linux_ipc_perm(struct ipc_perm *bpp, struct linux_ipc_perm *lpp)
    125 {
    126 
    127 	lpp->l_key = bpp->_key;
    128 	lpp->l_uid = bpp->uid;
    129 	lpp->l_gid = bpp->gid;
    130 	lpp->l_cuid = bpp->cuid;
    131 	lpp->l_cgid = bpp->cgid;
    132 	lpp->l_mode = bpp->mode;
    133 	lpp->l_seq = bpp->_seq;
    134 }
    135 
    136 void
    137 bsd_to_linux_ipc64_perm(struct ipc_perm *bpp, struct linux_ipc64_perm *lpp)
    138 {
    139 	lpp->l_key = bpp->_key;
    140 	lpp->l_uid = bpp->uid;
    141 	lpp->l_gid = bpp->gid;
    142 	lpp->l_cuid = bpp->cuid;
    143 	lpp->l_cgid = bpp->cgid;
    144 	lpp->l_mode = bpp->mode;
    145 	lpp->l_seq = bpp->_seq;
    146 }
    147 
    148 #endif
    149 
    150 #ifdef SYSVSEM
    151 /*
    152  * Semaphore operations. Most constants and structures are the same on
    153  * both systems. Only semctl() needs some extra work.
    154  */
    155 
    156 /*
    157  * Convert between Linux and NetBSD semid_ds structures.
    158  */
    159 void
    160 bsd_to_linux_semid_ds(struct semid_ds *bs, struct linux_semid_ds *ls)
    161 {
    162 
    163 	bsd_to_linux_ipc_perm(&bs->sem_perm, &ls->l_sem_perm);
    164 	ls->l_sem_otime = bs->sem_otime;
    165 	ls->l_sem_ctime = bs->sem_ctime;
    166 	ls->l_sem_nsems = bs->sem_nsems;
    167 	ls->l_sem_base = bs->_sem_base;
    168 }
    169 
    170 void
    171 linux_to_bsd_semid_ds(struct linux_semid_ds *ls, struct semid_ds *bs)
    172 {
    173 
    174 	linux_to_bsd_ipc_perm(&ls->l_sem_perm, &bs->sem_perm);
    175 	bs->sem_otime = ls->l_sem_otime;
    176 	bs->sem_ctime = ls->l_sem_ctime;
    177 	bs->sem_nsems = ls->l_sem_nsems;
    178 	bs->_sem_base = ls->l_sem_base;
    179 }
    180 
    181 /*
    182  * Most of this can be handled by directly passing the arguments on; we
    183  * just need to frob the `cmd' and convert the semid_ds and semun.
    184  */
    185 int
    186 linux_sys_semctl(struct lwp *l, const struct linux_sys_semctl_args *uap, register_t *retval)
    187 {
    188 	/* {
    189 		syscallarg(int) semid;
    190 		syscallarg(int) semnum;
    191 		syscallarg(int) cmd;
    192 		syscallarg(union linux_semun) arg;
    193 	} */
    194 	struct semid_ds sembuf;
    195 	struct linux_semid_ds lsembuf;
    196 	union __semun semun;
    197 	int cmd, error;
    198 	void *pass_arg = NULL;
    199 
    200 	cmd = SCARG(uap, cmd);
    201 
    202 	switch (cmd) {
    203 	case LINUX_IPC_SET:
    204 		pass_arg = &sembuf;
    205 		cmd = IPC_SET;
    206 		break;
    207 
    208 	case LINUX_IPC_STAT:
    209 		pass_arg = &sembuf;
    210 		cmd = IPC_STAT;
    211 		break;
    212 
    213 	case LINUX_IPC_RMID:
    214 		cmd = IPC_RMID;
    215 		break;
    216 
    217 	case LINUX_GETVAL:
    218 		cmd = GETVAL;
    219 		break;
    220 
    221 	case LINUX_GETPID:
    222 		cmd = GETPID;
    223 		break;
    224 
    225 	case LINUX_GETNCNT:
    226 		cmd = GETNCNT;
    227 		break;
    228 
    229 	case LINUX_GETZCNT:
    230 		cmd = GETZCNT;
    231 		break;
    232 
    233 	case LINUX_GETALL:
    234 		pass_arg = &semun;
    235 		semun.array = SCARG(uap, arg).l_array;
    236 		cmd = GETALL;
    237 		break;
    238 
    239 	case LINUX_SETVAL:
    240 		pass_arg = &semun;
    241 		semun.val = SCARG(uap, arg).l_val;
    242 		cmd = SETVAL;
    243 		break;
    244 
    245 	case LINUX_SETALL:
    246 		pass_arg = &semun;
    247 		semun.array = SCARG(uap, arg).l_array;
    248 		cmd = SETALL;
    249 		break;
    250 
    251 	default:
    252 		return (EINVAL);
    253 	}
    254 
    255 	if (cmd == IPC_SET) {
    256 		error = copyin(SCARG(uap, arg).l_buf, &lsembuf,
    257 		    sizeof(lsembuf));
    258 		if (error)
    259 			return (error);
    260 		linux_to_bsd_semid_ds(&lsembuf, &sembuf);
    261 	}
    262 
    263 	error = semctl1(l, SCARG(uap, semid), SCARG(uap, semnum), cmd,
    264 	    pass_arg, retval);
    265 
    266 	if (error == 0 && cmd == IPC_STAT) {
    267 		bsd_to_linux_semid_ds(&sembuf, &lsembuf);
    268 		error = copyout(&lsembuf, SCARG(uap, arg).l_buf,
    269 		    sizeof(lsembuf));
    270 	}
    271 
    272 	return (error);
    273 }
    274 #endif /* SYSVSEM */
    275 
    276 #ifdef SYSVMSG
    277 
    278 void
    279 linux_to_bsd_msqid_ds(struct linux_msqid_ds *lmp, struct msqid_ds *bmp)
    280 {
    281 
    282 	linux_to_bsd_ipc_perm(&lmp->l_msg_perm, &bmp->msg_perm);
    283 	bmp->_msg_first = lmp->l_msg_first;
    284 	bmp->_msg_last = lmp->l_msg_last;
    285 	bmp->_msg_cbytes = lmp->l_msg_cbytes;
    286 	bmp->msg_qnum = lmp->l_msg_qnum;
    287 	bmp->msg_qbytes = lmp->l_msg_qbytes;
    288 	bmp->msg_lspid = lmp->l_msg_lspid;
    289 	bmp->msg_lrpid = lmp->l_msg_lrpid;
    290 	bmp->msg_stime = lmp->l_msg_stime;
    291 	bmp->msg_rtime = lmp->l_msg_rtime;
    292 	bmp->msg_ctime = lmp->l_msg_ctime;
    293 }
    294 
    295 void
    296 bsd_to_linux_msqid_ds(struct msqid_ds *bmp, struct linux_msqid_ds *lmp)
    297 {
    298 
    299 	bsd_to_linux_ipc_perm(&bmp->msg_perm, &lmp->l_msg_perm);
    300 	lmp->l_msg_first = bmp->_msg_first;
    301 	lmp->l_msg_last = bmp->_msg_last;
    302 	lmp->l_msg_cbytes = bmp->_msg_cbytes;
    303 	lmp->l_msg_qnum = bmp->msg_qnum;
    304 	lmp->l_msg_qbytes = bmp->msg_qbytes;
    305 	lmp->l_msg_lspid = bmp->msg_lspid;
    306 	lmp->l_msg_lrpid = bmp->msg_lrpid;
    307 	lmp->l_msg_stime = bmp->msg_stime;
    308 	lmp->l_msg_rtime = bmp->msg_rtime;
    309 	lmp->l_msg_ctime = bmp->msg_ctime;
    310 }
    311 
    312 int
    313 linux_sys_msgctl(struct lwp *l, const struct linux_sys_msgctl_args *uap, register_t *retval)
    314 {
    315 	/* {
    316 		syscallarg(int) msqid;
    317 		syscallarg(int) cmd;
    318 		syscallarg(struct linux_msqid_ds *) buf;
    319 	} */
    320 	struct msqid_ds bm;
    321 	struct linux_msqid_ds lm;
    322 	int error;
    323 
    324 	switch (SCARG(uap, cmd)) {
    325 	case LINUX_IPC_STAT:
    326 		error = msgctl1(l, SCARG(uap, msqid), IPC_STAT, &bm);
    327 		if (error == 0) {
    328 			bsd_to_linux_msqid_ds(&bm, &lm);
    329 			error = copyout(&lm, SCARG(uap, buf), sizeof lm);
    330 		}
    331 		return error;
    332 	case LINUX_IPC_SET:
    333 		if ((error = copyin(SCARG(uap, buf), &lm, sizeof lm)))
    334 			return error;
    335 		linux_to_bsd_msqid_ds(&lm, &bm);
    336 		return msgctl1(l, SCARG(uap, msqid), IPC_SET, &bm);
    337 	case LINUX_IPC_RMID:
    338 		return msgctl1(l, SCARG(uap, msqid), IPC_RMID, NULL);
    339 		break;
    340 	default:
    341 		return EINVAL;
    342 	}
    343 }
    344 #endif /* SYSVMSG */
    345 
    346 #ifdef SYSVSHM
    347 /*
    348  * shmget(2). Just make sure the Linux-compatible shmat() semantics
    349  * is enabled for the segment, so that shmat() succeeds even when
    350  * the segment would be removed.
    351  */
    352 int
    353 linux_sys_shmget(struct lwp *l, const struct linux_sys_shmget_args *uap, register_t *retval)
    354 {
    355 	/* {
    356 		syscallarg(key_t) key;
    357 		syscallarg(size_t) size;
    358 		syscallarg(int) shmflg;
    359 	} */
    360 	struct sys_shmget_args bsd_ua;
    361 
    362 	SCARG(&bsd_ua, key) = SCARG(uap, key);
    363 	SCARG(&bsd_ua, size) = SCARG(uap, size);
    364 	SCARG(&bsd_ua, shmflg) = SCARG(uap, shmflg) | _SHM_RMLINGER;
    365 
    366 	return sys_shmget(l, &bsd_ua, retval);
    367 }
    368 
    369 /*
    370  * shmat(2). Very straightforward, except that Linux passes a pointer
    371  * in which the return value is to be passed. This is subsequently
    372  * handled by libc, apparently.
    373  */
    374 #ifndef __amd64__
    375 int
    376 linux_sys_shmat(struct lwp *l, const struct linux_sys_shmat_args *uap, register_t *retval)
    377 {
    378 	/* {
    379 		syscallarg(int) shmid;
    380 		syscallarg(void *) shmaddr;
    381 		syscallarg(int) shmflg;
    382 		syscallarg(u_long *) raddr;
    383 	} */
    384 	int error;
    385 
    386 	if ((error = sys_shmat(l, (const void *)uap, retval)))
    387 		return error;
    388 
    389 #ifndef __amd64__
    390 	if ((error = copyout(&retval[0], SCARG(uap, raddr), sizeof retval[0])))
    391 		return error;
    392 
    393 	retval[0] = 0;
    394 #endif
    395 	return 0;
    396 }
    397 #endif /* __amd64__ */
    398 
    399 /*
    400  * Convert between Linux and NetBSD shmid_ds structures.
    401  * The order of the fields is once again the difference, and
    402  * we also need a place to store the internal data pointer
    403  * in, which is unfortunately stored in this structure.
    404  *
    405  * We abuse a Linux internal field for that.
    406  */
    407 void
    408 linux_to_bsd_shmid_ds(struct linux_shmid_ds *lsp, struct shmid_ds *bsp)
    409 {
    410 
    411 	linux_to_bsd_ipc_perm(&lsp->l_shm_perm, &bsp->shm_perm);
    412 	bsp->shm_segsz = lsp->l_shm_segsz;
    413 	bsp->shm_lpid = lsp->l_shm_lpid;
    414 	bsp->shm_cpid = lsp->l_shm_cpid;
    415 	bsp->shm_nattch = lsp->l_shm_nattch;
    416 	bsp->shm_atime = lsp->l_shm_atime;
    417 	bsp->shm_dtime = lsp->l_shm_dtime;
    418 	bsp->shm_ctime = lsp->l_shm_ctime;
    419 	bsp->_shm_internal = lsp->l_private2;	/* XXX Oh well. */
    420 }
    421 
    422 void
    423 linux_to_bsd_shmid64_ds(struct linux_shmid64_ds *lsp, struct shmid_ds *bsp)
    424 {
    425 
    426 	linux_to_bsd_ipc64_perm(&lsp->l_shm_perm, &bsp->shm_perm);
    427 	bsp->shm_segsz = lsp->l_shm_segsz;
    428 	bsp->shm_lpid = lsp->l_shm_lpid;
    429 	bsp->shm_cpid = lsp->l_shm_cpid;
    430 	bsp->shm_nattch = lsp->l_shm_nattch;
    431 	bsp->shm_atime = lsp->l_shm_atime;
    432 	bsp->shm_dtime = lsp->l_shm_dtime;
    433 	bsp->shm_ctime = lsp->l_shm_ctime;
    434 	bsp->_shm_internal = (void*)lsp->l___unused5;	/* XXX Oh well. */
    435 }
    436 
    437 void
    438 bsd_to_linux_shmid_ds(struct shmid_ds *bsp, struct linux_shmid_ds *lsp)
    439 {
    440 
    441 	bsd_to_linux_ipc_perm(&bsp->shm_perm, &lsp->l_shm_perm);
    442 	lsp->l_shm_segsz = bsp->shm_segsz;
    443 	lsp->l_shm_lpid = bsp->shm_lpid;
    444 	lsp->l_shm_cpid = bsp->shm_cpid;
    445 	lsp->l_shm_nattch = bsp->shm_nattch;
    446 	lsp->l_shm_atime = bsp->shm_atime;
    447 	lsp->l_shm_dtime = bsp->shm_dtime;
    448 	lsp->l_shm_ctime = bsp->shm_ctime;
    449 	lsp->l_private2 = bsp->_shm_internal;	/* XXX */
    450 }
    451 
    452 void
    453 bsd_to_linux_shmid64_ds(struct shmid_ds *bsp, struct linux_shmid64_ds *lsp)
    454 {
    455 	bsd_to_linux_ipc64_perm(&bsp->shm_perm, &lsp->l_shm_perm);
    456 	lsp->l_shm_segsz = bsp->shm_segsz;
    457 	lsp->l_shm_lpid = bsp->shm_lpid;
    458 	lsp->l_shm_cpid = bsp->shm_cpid;
    459 	lsp->l_shm_nattch = bsp->shm_nattch;
    460 	lsp->l_shm_atime = bsp->shm_atime;
    461 	lsp->l_shm_dtime = bsp->shm_dtime;
    462 	lsp->l_shm_ctime = bsp->shm_ctime;
    463 	lsp->l___unused5 = (u_long)bsp->_shm_internal;	/* XXX */
    464 }
    465 
    466 /*
    467  * shmctl.SHM_LOCK and SHM_UNLOCK are passed on, but currently not implemented
    468  * by NetBSD itself.
    469  *
    470  * The usual structure conversion and massaging is done.
    471  */
    472 int
    473 linux_sys_shmctl(struct lwp *l, const struct linux_sys_shmctl_args *uap, register_t *retval)
    474 {
    475 	/* {
    476 		syscallarg(int) shmid;
    477 		syscallarg(int) cmd;
    478 		syscallarg(struct linux_shmid_ds *) buf;
    479 	} */
    480 	struct shmid_ds bs;
    481 	struct linux_shmid_ds ls;
    482 	struct linux_shmid64_ds ls64;
    483 	struct linux_shminfo64 lsi64;
    484 	struct linux_shm_info lsi;
    485 	int error, i, cmd, shmid;
    486 
    487 	shmid = SCARG(uap, shmid);
    488 	cmd = SCARG(uap, cmd);
    489 #ifdef LINUX_SHMCTL_FORCEIPC64
    490 	if (cmd == LINUX_IPC_STAT || cmd == LINUX_SHM_STAT)
    491 		cmd |= LINUX_IPC_64;
    492 #endif
    493 
    494 	switch (cmd) {
    495 	case LINUX_IPC_STAT:
    496 	case LINUX_SHM_STAT:
    497 		if (cmd == LINUX_SHM_STAT) {
    498 			shmid = IXSEQ_TO_IPCID(shmid, shmsegs[shmid].shm_perm);
    499 			retval[0] = shmid;
    500 		}
    501 		error = shmctl1(l, shmid, IPC_STAT, &bs);
    502 		if (error != 0)
    503 			return error;
    504 		bsd_to_linux_shmid_ds(&bs, &ls);
    505 		return copyout(&ls, SCARG(uap, buf), sizeof ls);
    506 
    507 	case LINUX_IPC_STAT | LINUX_IPC_64:
    508 	case LINUX_SHM_STAT | LINUX_IPC_64:
    509 		if (cmd == (LINUX_SHM_STAT | LINUX_IPC_64)) {
    510 			shmid = IXSEQ_TO_IPCID(shmid, shmsegs[shmid].shm_perm);
    511 			retval[0] = shmid;
    512 		}
    513 		error = shmctl1(l, shmid, IPC_STAT, &bs);
    514 		if (error != 0)
    515 			return error;
    516 		bsd_to_linux_shmid64_ds(&bs, &ls64);
    517 		return copyout(&ls64, SCARG(uap, buf), sizeof ls64);
    518 
    519 	case LINUX_IPC_SET:
    520 		if ((error = copyin(SCARG(uap, buf), &ls, sizeof ls)))
    521 			return error;
    522 		linux_to_bsd_shmid_ds(&ls, &bs);
    523 		return shmctl1(l, shmid, IPC_SET, &bs);
    524 
    525 	case LINUX_IPC_RMID:
    526 		return shmctl1(l, shmid, IPC_RMID, NULL);
    527 
    528 	case LINUX_SHM_LOCK:
    529 		return shmctl1(l, shmid, SHM_LOCK, NULL);
    530 
    531 	case LINUX_SHM_UNLOCK:
    532 		return shmctl1(l, shmid, SHM_UNLOCK, NULL);
    533 
    534 	case LINUX_IPC_INFO:
    535 		memset(&lsi64, 0, sizeof lsi64);
    536 		lsi64.l_shmmax = shminfo.shmmax;
    537 		lsi64.l_shmmin = shminfo.shmmin;
    538 		lsi64.l_shmmni = shminfo.shmmni;
    539 		lsi64.l_shmseg = shminfo.shmseg;
    540 		lsi64.l_shmall = shminfo.shmall;
    541 		for (i = shminfo.shmmni - 1; i > 0; i--)
    542 			if (shmsegs[i].shm_perm.mode & SHMSEG_ALLOCATED)
    543 				break;
    544 		retval[0] = i;
    545 		return copyout(&lsi64, SCARG(uap, buf), sizeof lsi64);
    546 
    547 	case LINUX_SHM_INFO:
    548 		(void)memset(&lsi, 0, sizeof lsi);
    549 		lsi.l_used_ids = shm_nused;
    550 		for (i = 0; i < shminfo.shmmni; i++)
    551 			if (shmsegs[i].shm_perm.mode & SHMSEG_ALLOCATED)
    552 				lsi.l_shm_tot +=
    553 				    round_page(shmsegs[i].shm_segsz) /
    554 				    uvmexp.pagesize;
    555 		lsi.l_shm_rss = 0;
    556 		lsi.l_shm_swp = 0;
    557 		lsi.l_swap_attempts = 0;
    558 		lsi.l_swap_successes = 0;
    559 		for (i = shminfo.shmmni - 1; i > 0; i--)
    560 			if (shmsegs[i].shm_perm.mode & SHMSEG_ALLOCATED)
    561 				break;
    562 		retval[0] = i;
    563 		return copyout(&lsi, SCARG(uap, buf), sizeof lsi);
    564 
    565 	default:
    566 #ifdef DEBUG
    567 		printf("linux_sys_shmctl cmd %d\n", SCARG(uap, cmd));
    568 #endif
    569 		return EINVAL;
    570 	}
    571 }
    572 #endif /* SYSVSHM */
    573