[unix-history] / usr / src / sys / kern / sysv_shm.c

/*
 * Copyright (c) 1988 University of Utah.
 * Copyright (c) 1990 The Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * the Systems Programming Group of the University of Utah Computer
 * Science Department. Originally from University of Wisconsin.
 *
 * %sccs.include.redist.c%
 *
 * from: Utah $Hdr: uipc_shm.c 1.9 89/08/14$
 *
 *	@(#)sysv_shm.c	7.6 (Berkeley) %G%
 */

/*
 * System V shared memory routines.
 */

#ifdef SYSVSHM

#include "machine/pte.h"

#include "param.h"
#include "systm.h"
#include "syscontext.h"
#include "kernel.h"
#include "proc.h"
#include "vm.h"
#include "shm.h"
#include "mapmem.h"
#include "malloc.h"

#ifdef HPUXCOMPAT
#include "../hpux/hpux.h"
#endif

int	shmat(), shmctl(), shmdt(), shmget();
int	(*shmcalls[])() = { shmat, shmctl, shmdt, shmget };
int	shmtot = 0;

int	shmfork(), shmexit();
struct	mapmemops shmops = { shmfork, (int (*)())0, shmexit, shmexit };

shminit()
{
	register int i;

	if (shminfo.shmmni > SHMMMNI)
		shminfo.shmmni = SHMMMNI;
	for (i = 0; i < shminfo.shmmni; i++) {
		shmsegs[i].shm_perm.mode = 0;
		shmsegs[i].shm_perm.seq = 0;
	}
}

/*
 * Entry point for all SHM calls
 */
shmsys(p, uap, retval)
	struct proc *p;
	struct args {
		int which;
	} *uap;
	int *retval;
{

	if (uap->which >= sizeof(shmcalls)/sizeof(shmcalls[0]))
		RETURN (EINVAL);
	RETURN ((*shmcalls[uap->which])(p, &uap[1], retval));
}

/*
 * Get a shared memory segment
 */
shmget(p, uap, retval)
	struct proc *p;
	register struct args {
		key_t key;
		int size;
		int shmflg;
	} *uap;
	int *retval;
{
	register struct shmid_ds *shp;
	register struct ucred *cred = u.u_cred;
	register int i;
	int error, size, rval = 0;
	caddr_t kva;

	/* look up the specified shm_id */
	if (uap->key != IPC_PRIVATE) {
		for (i = 0; i < shminfo.shmmni; i++)
			if ((shmsegs[i].shm_perm.mode & SHM_ALLOC) &&
			    shmsegs[i].shm_perm.key == uap->key) {
				rval = i;
				break;
			}
	} else
		i = shminfo.shmmni;

	/* create a new shared segment if necessary */
	if (i == shminfo.shmmni) {
		if ((uap->shmflg & IPC_CREAT) == 0)
			return (ENOENT);
		if (uap->size < shminfo.shmmin || uap->size > shminfo.shmmax)
			return (EINVAL);
		for (i = 0; i < shminfo.shmmni; i++)
			if ((shmsegs[i].shm_perm.mode & SHM_ALLOC) == 0) {
				rval = i;
				break;
			}
		if (i == shminfo.shmmni)
			return (ENOSPC);
		size = clrnd(btoc(uap->size));
		if (shmtot + size > shminfo.shmall)
			return (ENOMEM);
		shp = &shmsegs[rval];
		/*
		 * We need to do a couple of things to ensure consistency
		 * in case we sleep in malloc().  We mark segment as
		 * allocated so that other shmgets() will not allocate it.
		 * We mark it as "destroyed" to insure that shmvalid() is
		 * false making most operations fail (XXX).  We set the key,
		 * so that other shmget()s will fail.
		 */
		shp->shm_perm.mode = SHM_ALLOC | SHM_DEST;
		shp->shm_perm.key = uap->key;
		kva = (caddr_t) malloc((u_long)ctob(size), M_SHM, M_WAITOK);
		if (kva == NULL) {
			shp->shm_perm.mode = 0;
			return (ENOMEM);
		}
		if (!claligned(kva))
			panic("shmget: non-aligned memory");
		bzero(kva, (u_int)ctob(size));
		shmtot += size;
		shp->shm_perm.cuid = shp->shm_perm.uid = cred->cr_uid;
		shp->shm_perm.cgid = shp->shm_perm.gid = cred->cr_gid;
		shp->shm_perm.mode = SHM_ALLOC | (uap->shmflg&0777);
		shp->shm_handle = (void *) kvtopte(kva);
		shp->shm_segsz = uap->size;
		shp->shm_cpid = p->p_pid;
		shp->shm_lpid = shp->shm_nattch = 0;
		shp->shm_atime = shp->shm_dtime = 0;
		shp->shm_ctime = time.tv_sec;
	} else {
		shp = &shmsegs[rval];
		/* XXX: probably not the right thing to do */
		if (shp->shm_perm.mode & SHM_DEST)
			return (EBUSY);
		if (error = ipcaccess(cred, &shp->shm_perm, uap->shmflg&0777))
			return (error);
		if (uap->size && uap->size > shp->shm_segsz)
			return (EINVAL);
		if ((uap->shmflg&IPC_CREAT) && (uap->shmflg&IPC_EXCL))
			return (EEXIST);
	}
	*retval = shp->shm_perm.seq * SHMMMNI + rval;
}

/*
 * Shared memory control
 */
/* ARGSUSED */
shmctl(p, uap, retval)
	struct proc *p;
	register struct args {
		int shmid;
		int cmd;
		caddr_t buf;
	} *uap;
	int *retval;
{
	register struct shmid_ds *shp;
	register struct ucred *cred = u.u_cred;
	struct shmid_ds sbuf;
	int error;

	if (error = shmvalid(uap->shmid))
		return (error);
	shp = &shmsegs[uap->shmid % SHMMMNI];
	switch (uap->cmd) {
	case IPC_STAT:
		if (error = ipcaccess(cred, &shp->shm_perm, IPC_R))
			return (error);
		return (copyout((caddr_t)shp, uap->buf, sizeof(*shp)));

	case IPC_SET:
		if (cred->cr_uid && cred->cr_uid != shp->shm_perm.uid &&
		    cred->cr_uid != shp->shm_perm.cuid)
			return (EPERM);
		if (error = copyin(uap->buf, (caddr_t)&sbuf, sizeof sbuf))
			return (error);
		shp->shm_perm.uid = sbuf.shm_perm.uid;
		shp->shm_perm.gid = sbuf.shm_perm.gid;
		shp->shm_perm.mode = (shp->shm_perm.mode & ~0777)
			| (sbuf.shm_perm.mode & 0777);
		shp->shm_ctime = time.tv_sec;
		break;

	case IPC_RMID:
		if (cred->cr_uid && cred->cr_uid != shp->shm_perm.uid &&
		    cred->cr_uid != shp->shm_perm.cuid)
			return (EPERM);
		/* set ctime? */
		shp->shm_perm.key = IPC_PRIVATE;
		shp->shm_perm.mode |= SHM_DEST;
		if (shp->shm_nattch <= 0)
			shmfree(shp);
		break;

#ifdef HPUXCOMPAT
	case SHM_LOCK:
	case SHM_UNLOCK:
		/* don't really do anything, but make them think we did */
		if ((p->p_flag & SHPUX) == 0)
			return (EINVAL);
		if (cred->cr_uid && cred->cr_uid != shp->shm_perm.uid &&
		    cred->cr_uid != shp->shm_perm.cuid)
			return (EPERM);
		break;
#endif

	default:
		return (EINVAL);
	}
	return (0);
}

/*
 * Attach to shared memory segment.
 */
shmat(p, uap, retval)
	struct proc *p;
	register struct args {
		int	shmid;
		caddr_t	shmaddr;
		int	shmflg;
	} *uap;
	int *retval;
{
	register struct shmid_ds *shp;
	register int size;
	struct mapmem *mp;
	caddr_t uva;
	int error, error1, prot, shmmapin();

	if (error = shmvalid(uap->shmid))
		return (error);
	shp = &shmsegs[uap->shmid % SHMMMNI];
	if (shp->shm_handle == NULL)
		panic("shmat NULL handle");
	if (error = ipcaccess(u.u_cred, &shp->shm_perm,
		      (uap->shmflg&SHM_RDONLY) ? IPC_R : IPC_R|IPC_W))
		return (error);
	uva = uap->shmaddr;
	if (uva && ((int)uva & (SHMLBA-1))) {
		if (uap->shmflg & SHM_RND)
			uva = (caddr_t) ((int)uva & ~(SHMLBA-1));
		else
			return (EINVAL);
	}
	/*
	 * Make sure user doesn't use more than their fair share
	 */
	size = 0;
	for (mp = u.u_mmap; mp; mp = mp->mm_next)
		if (mp->mm_ops == &shmops)
			size++;
	if (size >= shminfo.shmseg)
		return (EMFILE);
	/*
	 * Allocate a mapped memory region descriptor and
	 * attempt to expand the user page table to allow for region
	 */
	prot = (uap->shmflg & SHM_RDONLY) ? MM_RO : MM_RW;
#if defined(hp300)
	prot |= MM_CI;
#endif
	size = ctob(clrnd(btoc(shp->shm_segsz)));
	error = mmalloc(p, uap->shmid, &uva, (segsz_t)size, prot, &shmops, &mp);
	if (error)
		return (error);
	if (error = mmmapin(p, mp, shmmapin)) {
		if (error1 = mmfree(p, mp))
			return (error1);
		return (error);
	}
	/*
	 * Fill in the remaining fields
	 */
	shp->shm_lpid = p->p_pid;
	shp->shm_atime = time.tv_sec;
	shp->shm_nattch++;
	*retval = (int) uva;
}

/*
 * Detach from shared memory segment.
 */
/* ARGSUSED */
shmdt(p, uap, retval)
	struct proc *p;
	struct args {
		caddr_t	shmaddr;
	} *uap;
	int *retval;
{
	register struct mapmem *mp;

	for (mp = u.u_mmap; mp; mp = mp->mm_next)
		if (mp->mm_ops == &shmops && mp->mm_uva == uap->shmaddr)
			break;
	if (mp == MMNIL)
		return (EINVAL);
	shmsegs[mp->mm_id % SHMMMNI].shm_lpid = p->p_pid;
	return (shmufree(p, mp));
}

shmmapin(mp, off)
	struct mapmem *mp;
{
	register struct shmid_ds *shp;

	shp = &shmsegs[mp->mm_id % SHMMMNI];
	if (off >= ctob(clrnd(btoc(shp->shm_segsz))))
		return(-1);
	return(((struct pte *)shp->shm_handle)[btop(off)].pg_pfnum);
}

/*
 * Increment attach count on fork
 */
/* ARGSUSED */
shmfork(mp, ischild)
	register struct mapmem *mp;
{
	if (!ischild)
		shmsegs[mp->mm_id % SHMMMNI].shm_nattch++;
}

/*
 * Detach from shared memory segment on exit (or exec)
 */
shmexit(p, mp)
	struct proc *p;
	struct mapmem *mp;
{

	return (shmufree(p, mp));
}

shmvalid(id)
	register int id;
{
	register struct shmid_ds *shp;

	if (id < 0 || (id % SHMMMNI) >= shminfo.shmmni)
		return(EINVAL);
	shp = &shmsegs[id % SHMMMNI];
	if (shp->shm_perm.seq == (id / SHMMMNI) &&
	    (shp->shm_perm.mode & (SHM_ALLOC|SHM_DEST)) == SHM_ALLOC)
		return(0);
	return(EINVAL);
}

/*
 * Free user resources associated with a shared memory segment
 */
shmufree(p, mp)
	struct proc *p;
	struct mapmem *mp;
{
	register struct shmid_ds *shp;
	int error;

	shp = &shmsegs[mp->mm_id % SHMMMNI];
	mmmapout(p, mp);
	error = mmfree(p, mp);
	shp->shm_dtime = time.tv_sec;
	if (--shp->shm_nattch <= 0 && (shp->shm_perm.mode & SHM_DEST))
		shmfree(shp);
	return (error);
}

/*
 * Deallocate resources associated with a shared memory segment
 */
shmfree(shp)
	register struct shmid_ds *shp;
{
	caddr_t kva;

	if (shp->shm_handle == NULL)
		panic("shmfree");
	kva = (caddr_t) ptetokv(shp->shm_handle);
	free(kva, M_SHM);
	shp->shm_handle = NULL;
	shmtot -= clrnd(btoc(shp->shm_segsz));
	shp->shm_perm.mode = 0;
	/*
	 * Increment the sequence number to ensure that outstanding
	 * shmids for this segment will be invalid in the event that
	 * the segment is reallocated.  Note that shmids must be
	 * positive as decreed by SVID.
	 */
	shp->shm_perm.seq++;
	if ((int)(shp->shm_perm.seq * SHMMMNI) < 0)
		shp->shm_perm.seq = 0;
}

/*
 * XXX This routine would be common to all sysV style IPC
 *     (if the others were implemented).
 */
ipcaccess(ipc, mode, cred)
	register struct ipc_perm *ipc;
	int mode;
	register struct ucred *cred;
{
	register int m;

	if (cred->cr_uid == 0)
		return(0);
	/*
	 * Access check is based on only one of owner, group, public.
	 * If not owner, then check group.
	 * If not a member of the group, then check public access.
	 */
	mode &= 0700;
	m = ipc->mode;
	if (cred->cr_uid != ipc->uid && cred->cr_uid != ipc->cuid) {
		m <<= 3;
		if (!groupmember(ipc->gid, cred) &&
		    !groupmember(ipc->cgid, cred))
			m <<= 3;
	}
	if ((mode&m) == mode)
		return (0);
	return (EACCES);
}

#endif /* SYSVSHM */
Commit	Line	Data
6f843dc9 KM	1	/*
	2	* Copyright (c) 1988 University of Utah.
	3	* Copyright (c) 1990 The Regents of the University of California.
	4	* All rights reserved.
	5	*
	6	* This code is derived from software contributed to Berkeley by
	7	* the Systems Programming Group of the University of Utah Computer
	8	* Science Department. Originally from University of Wisconsin.
	9	*
	10	* %sccs.include.redist.c%
	11	*
	12	* from: Utah $Hdr: uipc_shm.c 1.9 89/08/14$
	13	*
6be55866	14	* @(#)sysv_shm.c 7.6 (Berkeley) %G%
6f843dc9 KM	15	*/
	16
	17	/*
	18	* System V shared memory routines.
	19	*/
	20
	21	#ifdef SYSVSHM
	22
	23	#include "machine/pte.h"
	24
	25	#include "param.h"
	26	#include "systm.h"
161c14a2	27	#include "syscontext.h"
6f843dc9 KM	28	#include "kernel.h"
	29	#include "proc.h"
	30	#include "vm.h"
	31	#include "shm.h"
	32	#include "mapmem.h"
	33	#include "malloc.h"
	34
	35	#ifdef HPUXCOMPAT
	36	#include "../hpux/hpux.h"
	37	#endif
	38
	39	int shmat(), shmctl(), shmdt(), shmget();
	40	int (*shmcalls[])() = { shmat, shmctl, shmdt, shmget };
	41	int shmtot = 0;
	42
	43	int shmfork(), shmexit();
	44	struct mapmemops shmops = { shmfork, (int (*)())0, shmexit, shmexit };
	45
	46	shminit()
	47	{
	48	register int i;
	49
	50	if (shminfo.shmmni > SHMMMNI)
	51	shminfo.shmmni = SHMMMNI;
	52	for (i = 0; i < shminfo.shmmni; i++) {
	53	shmsegs[i].shm_perm.mode = 0;
	54	shmsegs[i].shm_perm.seq = 0;
	55	}
	56	}
	57
161c14a2 KM	58	/*
	59	* Entry point for all SHM calls
	60	*/
	61	shmsys(p, uap, retval)
	62	struct proc *p;
	63	struct args {
6f843dc9	64	int which;
161c14a2 KM	65	} *uap;
	66	int *retval;
	67	{
6f843dc9	68
161c14a2 KM	69	if (uap->which >= sizeof(shmcalls)/sizeof(shmcalls[0]))
	70	RETURN (EINVAL);
	71	RETURN ((*shmcalls[uap->which])(p, &uap[1], retval));
6f843dc9 KM	72	}
6f843dc9 KM	73
161c14a2 KM	74	/*
	75	* Get a shared memory segment
	76	*/
	77	shmget(p, uap, retval)
	78	struct proc *p;
	79	register struct args {
6f843dc9 KM	80	key_t key;
	81	int size;
	82	int shmflg;
161c14a2 KM	83	} *uap;
	84	int *retval;
	85	{
6f843dc9	86	register struct shmid_ds *shp;
161c14a2	87	register struct ucred *cred = u.u_cred;
6f843dc9	88	register int i;
161c14a2	89	int error, size, rval = 0;
6f843dc9 KM	90	caddr_t kva;
	91
	92	/* look up the specified shm_id */
	93	if (uap->key != IPC_PRIVATE) {
	94	for (i = 0; i < shminfo.shmmni; i++)
	95	if ((shmsegs[i].shm_perm.mode & SHM_ALLOC) &&
	96	shmsegs[i].shm_perm.key == uap->key) {
	97	rval = i;
	98	break;
	99	}
	100	} else
	101	i = shminfo.shmmni;
	102
	103	/* create a new shared segment if necessary */
	104	if (i == shminfo.shmmni) {
161c14a2 KM	105	if ((uap->shmflg & IPC_CREAT) == 0)
	106	return (ENOENT);
	107	if (uap->size < shminfo.shmmin \|\| uap->size > shminfo.shmmax)
	108	return (EINVAL);
6f843dc9 KM	109	for (i = 0; i < shminfo.shmmni; i++)
	110	if ((shmsegs[i].shm_perm.mode & SHM_ALLOC) == 0) {
	111	rval = i;
	112	break;
	113	}
161c14a2 KM	114	if (i == shminfo.shmmni)
161c14a2 KM	115	return (ENOSPC);
6f843dc9	116	size = clrnd(btoc(uap->size));
161c14a2 KM	117	if (shmtot + size > shminfo.shmall)
161c14a2 KM	118	return (ENOMEM);
6f843dc9 KM	119	shp = &shmsegs[rval];
	120	/*
	121	* We need to do a couple of things to ensure consistency
	122	* in case we sleep in malloc(). We mark segment as
	123	* allocated so that other shmgets() will not allocate it.
	124	* We mark it as "destroyed" to insure that shmvalid() is
	125	* false making most operations fail (XXX). We set the key,
	126	* so that other shmget()s will fail.
	127	*/
	128	shp->shm_perm.mode = SHM_ALLOC \| SHM_DEST;
	129	shp->shm_perm.key = uap->key;
	130	kva = (caddr_t) malloc((u_long)ctob(size), M_SHM, M_WAITOK);
	131	if (kva == NULL) {
	132	shp->shm_perm.mode = 0;
161c14a2	133	return (ENOMEM);
6f843dc9 KM	134	}
	135	if (!claligned(kva))
	136	panic("shmget: non-aligned memory");
	137	bzero(kva, (u_int)ctob(size));
	138	shmtot += size;
161c14a2 KM	139	shp->shm_perm.cuid = shp->shm_perm.uid = cred->cr_uid;
161c14a2 KM	140	shp->shm_perm.cgid = shp->shm_perm.gid = cred->cr_gid;
6f843dc9 KM	141	shp->shm_perm.mode = SHM_ALLOC \| (uap->shmflg&0777);
	142	shp->shm_handle = (void *) kvtopte(kva);
	143	shp->shm_segsz = uap->size;
c9714ae3	144	shp->shm_cpid = p->p_pid;
6f843dc9 KM	145	shp->shm_lpid = shp->shm_nattch = 0;
	146	shp->shm_atime = shp->shm_dtime = 0;
	147	shp->shm_ctime = time.tv_sec;
	148	} else {
	149	shp = &shmsegs[rval];
	150	/* XXX: probably not the right thing to do */
161c14a2 KM	151	if (shp->shm_perm.mode & SHM_DEST)
	152	return (EBUSY);
	153	if (error = ipcaccess(cred, &shp->shm_perm, uap->shmflg&0777))
	154	return (error);
	155	if (uap->size && uap->size > shp->shm_segsz)
	156	return (EINVAL);
	157	if ((uap->shmflg&IPC_CREAT) && (uap->shmflg&IPC_EXCL))
	158	return (EEXIST);
6f843dc9	159	}
161c14a2	160	retval = shp->shm_perm.seq SHMMMNI + rval;
6f843dc9 KM	161	}
6f843dc9 KM	162
161c14a2 KM	163	/*
	164	* Shared memory control
	165	*/
	166	/* ARGSUSED */
	167	shmctl(p, uap, retval)
	168	struct proc *p;
	169	register struct args {
6f843dc9 KM	170	int shmid;
	171	int cmd;
	172	caddr_t buf;
161c14a2 KM	173	} *uap;
	174	int *retval;
	175	{
6f843dc9	176	register struct shmid_ds *shp;
161c14a2	177	register struct ucred *cred = u.u_cred;
6f843dc9	178	struct shmid_ds sbuf;
161c14a2	179	int error;
6f843dc9	180
161c14a2 KM	181	if (error = shmvalid(uap->shmid))
161c14a2 KM	182	return (error);
6f843dc9 KM	183	shp = &shmsegs[uap->shmid % SHMMMNI];
	184	switch (uap->cmd) {
	185	case IPC_STAT:
161c14a2 KM	186	if (error = ipcaccess(cred, &shp->shm_perm, IPC_R))
	187	return (error);
	188	return (copyout((caddr_t)shp, uap->buf, sizeof(*shp)));
6f843dc9 KM	189
6f843dc9 KM	190	case IPC_SET:
161c14a2 KM	191	if (cred->cr_uid && cred->cr_uid != shp->shm_perm.uid &&
	192	cred->cr_uid != shp->shm_perm.cuid)
	193	return (EPERM);
	194	if (error = copyin(uap->buf, (caddr_t)&sbuf, sizeof sbuf))
	195	return (error);
	196	shp->shm_perm.uid = sbuf.shm_perm.uid;
	197	shp->shm_perm.gid = sbuf.shm_perm.gid;
	198	shp->shm_perm.mode = (shp->shm_perm.mode & ~0777)
	199	\| (sbuf.shm_perm.mode & 0777);
	200	shp->shm_ctime = time.tv_sec;
6f843dc9 KM	201	break;
	202
	203	case IPC_RMID:
161c14a2 KM	204	if (cred->cr_uid && cred->cr_uid != shp->shm_perm.uid &&
	205	cred->cr_uid != shp->shm_perm.cuid)
	206	return (EPERM);
6f843dc9 KM	207	/* set ctime? */
	208	shp->shm_perm.key = IPC_PRIVATE;
	209	shp->shm_perm.mode \|= SHM_DEST;
	210	if (shp->shm_nattch <= 0)
	211	shmfree(shp);
	212	break;
	213
	214	#ifdef HPUXCOMPAT
	215	case SHM_LOCK:
	216	case SHM_UNLOCK:
	217	/* don't really do anything, but make them think we did */
c9714ae3	218	if ((p->p_flag & SHPUX) == 0)
161c14a2 KM	219	return (EINVAL);
	220	if (cred->cr_uid && cred->cr_uid != shp->shm_perm.uid &&
	221	cred->cr_uid != shp->shm_perm.cuid)
	222	return (EPERM);
6f843dc9 KM	223	break;
	224	#endif
	225
	226	default:
161c14a2	227	return (EINVAL);
6f843dc9	228	}
161c14a2	229	return (0);
6f843dc9 KM	230	}
6f843dc9 KM	231
161c14a2 KM	232	/*
	233	* Attach to shared memory segment.
	234	*/
	235	shmat(p, uap, retval)
	236	struct proc *p;
	237	register struct args {
6f843dc9 KM	238	int shmid;
	239	caddr_t shmaddr;
	240	int shmflg;
161c14a2 KM	241	} *uap;
	242	int *retval;
	243	{
6f843dc9 KM	244	register struct shmid_ds *shp;
	245	register int size;
	246	struct mapmem *mp;
	247	caddr_t uva;
161c14a2	248	int error, error1, prot, shmmapin();
6f843dc9	249
161c14a2 KM	250	if (error = shmvalid(uap->shmid))
161c14a2 KM	251	return (error);
6f843dc9 KM	252	shp = &shmsegs[uap->shmid % SHMMMNI];
6f843dc9 KM	253	if (shp->shm_handle == NULL)
96ea38ce	254	panic("shmat NULL handle");
161c14a2	255	if (error = ipcaccess(u.u_cred, &shp->shm_perm,
6f843dc9	256	(uap->shmflg&SHM_RDONLY) ? IPC_R : IPC_R\|IPC_W))
161c14a2	257	return (error);
6f843dc9 KM	258	uva = uap->shmaddr;
	259	if (uva && ((int)uva & (SHMLBA-1))) {
	260	if (uap->shmflg & SHM_RND)
	261	uva = (caddr_t) ((int)uva & ~(SHMLBA-1));
161c14a2 KM	262	else
161c14a2 KM	263	return (EINVAL);
6f843dc9 KM	264	}
	265	/*
	266	* Make sure user doesn't use more than their fair share
	267	*/
	268	size = 0;
	269	for (mp = u.u_mmap; mp; mp = mp->mm_next)
	270	if (mp->mm_ops == &shmops)
	271	size++;
161c14a2 KM	272	if (size >= shminfo.shmseg)
161c14a2 KM	273	return (EMFILE);
6f843dc9 KM	274	/*
	275	* Allocate a mapped memory region descriptor and
	276	* attempt to expand the user page table to allow for region
	277	*/
	278	prot = (uap->shmflg & SHM_RDONLY) ? MM_RO : MM_RW;
	279	#if defined(hp300)
	280	prot \|= MM_CI;
	281	#endif
	282	size = ctob(clrnd(btoc(shp->shm_segsz)));
c9714ae3	283	error = mmalloc(p, uap->shmid, &uva, (segsz_t)size, prot, &shmops, &mp);
161c14a2 KM	284	if (error)
	285	return (error);
	286	if (error = mmmapin(p, mp, shmmapin)) {
	287	if (error1 = mmfree(p, mp))
	288	return (error1);
	289	return (error);
6f843dc9 KM	290	}
	291	/*
	292	* Fill in the remaining fields
	293	*/
c9714ae3	294	shp->shm_lpid = p->p_pid;
6f843dc9 KM	295	shp->shm_atime = time.tv_sec;
6f843dc9 KM	296	shp->shm_nattch++;
161c14a2	297	*retval = (int) uva;
6f843dc9 KM	298	}
6f843dc9 KM	299
161c14a2 KM	300	/*
	301	* Detach from shared memory segment.
	302	*/
	303	/* ARGSUSED */
	304	shmdt(p, uap, retval)
	305	struct proc *p;
	306	struct args {
6f843dc9	307	caddr_t shmaddr;
161c14a2 KM	308	} *uap;
	309	int *retval;
	310	{
6f843dc9 KM	311	register struct mapmem *mp;
	312
	313	for (mp = u.u_mmap; mp; mp = mp->mm_next)
	314	if (mp->mm_ops == &shmops && mp->mm_uva == uap->shmaddr)
	315	break;
161c14a2 KM	316	if (mp == MMNIL)
161c14a2 KM	317	return (EINVAL);
c9714ae3	318	shmsegs[mp->mm_id % SHMMMNI].shm_lpid = p->p_pid;
161c14a2	319	return (shmufree(p, mp));
6f843dc9 KM	320	}
	321
	322	shmmapin(mp, off)
	323	struct mapmem *mp;
	324	{
	325	register struct shmid_ds *shp;
	326
	327	shp = &shmsegs[mp->mm_id % SHMMMNI];
	328	if (off >= ctob(clrnd(btoc(shp->shm_segsz))))
	329	return(-1);
	330	return(((struct pte *)shp->shm_handle)[btop(off)].pg_pfnum);
	331	}
	332
	333	/*
	334	* Increment attach count on fork
	335	*/
6be55866	336	/* ARGSUSED */
6f843dc9 KM	337	shmfork(mp, ischild)
	338	register struct mapmem *mp;
	339	{
	340	if (!ischild)
	341	shmsegs[mp->mm_id % SHMMMNI].shm_nattch++;
	342	}
	343
	344	/*
	345	* Detach from shared memory segment on exit (or exec)
	346	*/
6be55866 KM	347	shmexit(p, mp)
	348	struct proc *p;
	349	struct mapmem *mp;
6f843dc9	350	{
c9714ae3	351
161c14a2	352	return (shmufree(p, mp));
6f843dc9 KM	353	}
	354
	355	shmvalid(id)
	356	register int id;
	357	{
	358	register struct shmid_ds *shp;
	359
	360	if (id < 0 \|\| (id % SHMMMNI) >= shminfo.shmmni)
161c14a2	361	return(EINVAL);
6f843dc9 KM	362	shp = &shmsegs[id % SHMMMNI];
	363	if (shp->shm_perm.seq == (id / SHMMMNI) &&
	364	(shp->shm_perm.mode & (SHM_ALLOC\|SHM_DEST)) == SHM_ALLOC)
161c14a2 KM	365	return(0);
161c14a2 KM	366	return(EINVAL);
6f843dc9 KM	367	}
	368
	369	/*
	370	* Free user resources associated with a shared memory segment
	371	*/
c9714ae3 KM	372	shmufree(p, mp)
c9714ae3 KM	373	struct proc *p;
6f843dc9 KM	374	struct mapmem *mp;
	375	{
	376	register struct shmid_ds *shp;
c9714ae3	377	int error;
6f843dc9 KM	378
6f843dc9 KM	379	shp = &shmsegs[mp->mm_id % SHMMMNI];
c9714ae3 KM	380	mmmapout(p, mp);
c9714ae3 KM	381	error = mmfree(p, mp);
6f843dc9 KM	382	shp->shm_dtime = time.tv_sec;
	383	if (--shp->shm_nattch <= 0 && (shp->shm_perm.mode & SHM_DEST))
	384	shmfree(shp);
c9714ae3	385	return (error);
6f843dc9 KM	386	}
	387
	388	/*
	389	* Deallocate resources associated with a shared memory segment
	390	*/
	391	shmfree(shp)
	392	register struct shmid_ds *shp;
	393	{
	394	caddr_t kva;
	395
	396	if (shp->shm_handle == NULL)
	397	panic("shmfree");
	398	kva = (caddr_t) ptetokv(shp->shm_handle);
	399	free(kva, M_SHM);
	400	shp->shm_handle = NULL;
	401	shmtot -= clrnd(btoc(shp->shm_segsz));
	402	shp->shm_perm.mode = 0;
	403	/*
	404	* Increment the sequence number to ensure that outstanding
	405	* shmids for this segment will be invalid in the event that
	406	* the segment is reallocated. Note that shmids must be
	407	* positive as decreed by SVID.
	408	*/
	409	shp->shm_perm.seq++;
	410	if ((int)(shp->shm_perm.seq * SHMMMNI) < 0)
	411	shp->shm_perm.seq = 0;
	412	}
	413
	414	/*
	415	* XXX This routine would be common to all sysV style IPC
	416	* (if the others were implemented).
	417	*/
161c14a2	418	ipcaccess(ipc, mode, cred)
6f843dc9	419	register struct ipc_perm *ipc;
161c14a2 KM	420	int mode;
161c14a2 KM	421	register struct ucred *cred;
6f843dc9 KM	422	{
	423	register int m;
	424
161c14a2	425	if (cred->cr_uid == 0)
6f843dc9 KM	426	return(0);
	427	/*
	428	* Access check is based on only one of owner, group, public.
	429	* If not owner, then check group.
	430	* If not a member of the group, then check public access.
	431	*/
	432	mode &= 0700;
	433	m = ipc->mode;
161c14a2	434	if (cred->cr_uid != ipc->uid && cred->cr_uid != ipc->cuid) {
6f843dc9	435	m <<= 3;
161c14a2 KM	436	if (!groupmember(ipc->gid, cred) &&
161c14a2 KM	437	!groupmember(ipc->cgid, cred))
6f843dc9 KM	438	m <<= 3;
	439	}
	440	if ((mode&m) == mode)
161c14a2 KM	441	return (0);
161c14a2 KM	442	return (EACCES);
6f843dc9 KM	443	}
	444
	445	#endif /* SYSVSHM */