[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	7.7 (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(&shp->shm_perm, uap->shmflg&0777, cred))
			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;
	return (0);
}

/*
 * 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(&shp->shm_perm, IPC_R, cred))
			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, 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(&shp->shm_perm,
			(uap->shmflg&SHM_RDONLY) ? IPC_R : IPC_R|IPC_W, u.u_cred))
		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)) {
		(void) mmfree(p, mp);
		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;
	return (0);
}

/*
 * 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(mp)
	struct mapmem *mp;
{
	struct proc *p = u.u_procp;		/* XXX */

	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	*
015c074c	14	* @(#)sysv_shm.c 7.7 (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)
161c14a2 KM	152	return (EBUSY);
015c074c	153	if (error = ipcaccess(&shp->shm_perm, uap->shmflg&0777, cred))
161c14a2 KM	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;
015c074c	161	return (0);
6f843dc9 KM	162	}
6f843dc9 KM	163
161c14a2 KM	164	/*
	165	* Shared memory control
	166	*/
	167	/* ARGSUSED */
	168	shmctl(p, uap, retval)
	169	struct proc *p;
	170	register struct args {
6f843dc9 KM	171	int shmid;
	172	int cmd;
	173	caddr_t buf;
161c14a2 KM	174	} *uap;
	175	int *retval;
	176	{
6f843dc9	177	register struct shmid_ds *shp;
161c14a2	178	register struct ucred *cred = u.u_cred;
6f843dc9	179	struct shmid_ds sbuf;
161c14a2	180	int error;
6f843dc9	181
161c14a2 KM	182	if (error = shmvalid(uap->shmid))
161c14a2 KM	183	return (error);
6f843dc9 KM	184	shp = &shmsegs[uap->shmid % SHMMMNI];
	185	switch (uap->cmd) {
	186	case IPC_STAT:
015c074c	187	if (error = ipcaccess(&shp->shm_perm, IPC_R, cred))
161c14a2 KM	188	return (error);
161c14a2 KM	189	return (copyout((caddr_t)shp, uap->buf, sizeof(*shp)));
6f843dc9 KM	190
6f843dc9 KM	191	case IPC_SET:
161c14a2 KM	192	if (cred->cr_uid && cred->cr_uid != shp->shm_perm.uid &&
	193	cred->cr_uid != shp->shm_perm.cuid)
	194	return (EPERM);
	195	if (error = copyin(uap->buf, (caddr_t)&sbuf, sizeof sbuf))
	196	return (error);
	197	shp->shm_perm.uid = sbuf.shm_perm.uid;
	198	shp->shm_perm.gid = sbuf.shm_perm.gid;
	199	shp->shm_perm.mode = (shp->shm_perm.mode & ~0777)
	200	\| (sbuf.shm_perm.mode & 0777);
	201	shp->shm_ctime = time.tv_sec;
6f843dc9 KM	202	break;
	203
	204	case IPC_RMID:
161c14a2 KM	205	if (cred->cr_uid && cred->cr_uid != shp->shm_perm.uid &&
	206	cred->cr_uid != shp->shm_perm.cuid)
	207	return (EPERM);
6f843dc9 KM	208	/* set ctime? */
	209	shp->shm_perm.key = IPC_PRIVATE;
	210	shp->shm_perm.mode \|= SHM_DEST;
	211	if (shp->shm_nattch <= 0)
	212	shmfree(shp);
	213	break;
	214
	215	#ifdef HPUXCOMPAT
	216	case SHM_LOCK:
	217	case SHM_UNLOCK:
	218	/* don't really do anything, but make them think we did */
c9714ae3	219	if ((p->p_flag & SHPUX) == 0)
161c14a2 KM	220	return (EINVAL);
	221	if (cred->cr_uid && cred->cr_uid != shp->shm_perm.uid &&
	222	cred->cr_uid != shp->shm_perm.cuid)
	223	return (EPERM);
6f843dc9 KM	224	break;
	225	#endif
	226
	227	default:
161c14a2	228	return (EINVAL);
6f843dc9	229	}
161c14a2	230	return (0);
6f843dc9 KM	231	}
6f843dc9 KM	232
161c14a2 KM	233	/*
	234	* Attach to shared memory segment.
	235	*/
	236	shmat(p, uap, retval)
	237	struct proc *p;
	238	register struct args {
6f843dc9 KM	239	int shmid;
	240	caddr_t shmaddr;
	241	int shmflg;
161c14a2 KM	242	} *uap;
	243	int *retval;
	244	{
6f843dc9 KM	245	register struct shmid_ds *shp;
	246	register int size;
	247	struct mapmem *mp;
	248	caddr_t uva;
015c074c	249	int error, prot, shmmapin();
6f843dc9	250
161c14a2 KM	251	if (error = shmvalid(uap->shmid))
161c14a2 KM	252	return (error);
6f843dc9 KM	253	shp = &shmsegs[uap->shmid % SHMMMNI];
6f843dc9 KM	254	if (shp->shm_handle == NULL)
96ea38ce	255	panic("shmat NULL handle");
015c074c MH	256	if (error = ipcaccess(&shp->shm_perm,
015c074c MH	257	(uap->shmflg&SHM_RDONLY) ? IPC_R : IPC_R\|IPC_W, u.u_cred))
161c14a2	258	return (error);
6f843dc9 KM	259	uva = uap->shmaddr;
	260	if (uva && ((int)uva & (SHMLBA-1))) {
	261	if (uap->shmflg & SHM_RND)
	262	uva = (caddr_t) ((int)uva & ~(SHMLBA-1));
161c14a2 KM	263	else
161c14a2 KM	264	return (EINVAL);
6f843dc9 KM	265	}
	266	/*
	267	* Make sure user doesn't use more than their fair share
	268	*/
	269	size = 0;
	270	for (mp = u.u_mmap; mp; mp = mp->mm_next)
	271	if (mp->mm_ops == &shmops)
	272	size++;
161c14a2 KM	273	if (size >= shminfo.shmseg)
161c14a2 KM	274	return (EMFILE);
6f843dc9 KM	275	/*
	276	* Allocate a mapped memory region descriptor and
	277	* attempt to expand the user page table to allow for region
	278	*/
	279	prot = (uap->shmflg & SHM_RDONLY) ? MM_RO : MM_RW;
	280	#if defined(hp300)
	281	prot \|= MM_CI;
	282	#endif
	283	size = ctob(clrnd(btoc(shp->shm_segsz)));
c9714ae3	284	error = mmalloc(p, uap->shmid, &uva, (segsz_t)size, prot, &shmops, &mp);
161c14a2 KM	285	if (error)
	286	return (error);
	287	if (error = mmmapin(p, mp, shmmapin)) {
015c074c	288	(void) mmfree(p, mp);
161c14a2	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;
015c074c	298	return (0);
6f843dc9 KM	299	}
6f843dc9 KM	300
161c14a2 KM	301	/*
	302	* Detach from shared memory segment.
	303	*/
	304	/* ARGSUSED */
	305	shmdt(p, uap, retval)
	306	struct proc *p;
	307	struct args {
6f843dc9	308	caddr_t shmaddr;
161c14a2 KM	309	} *uap;
	310	int *retval;
	311	{
6f843dc9 KM	312	register struct mapmem *mp;
	313
	314	for (mp = u.u_mmap; mp; mp = mp->mm_next)
	315	if (mp->mm_ops == &shmops && mp->mm_uva == uap->shmaddr)
	316	break;
161c14a2 KM	317	if (mp == MMNIL)
161c14a2 KM	318	return (EINVAL);
c9714ae3	319	shmsegs[mp->mm_id % SHMMMNI].shm_lpid = p->p_pid;
161c14a2	320	return (shmufree(p, mp));
6f843dc9 KM	321	}
	322
	323	shmmapin(mp, off)
	324	struct mapmem *mp;
	325	{
	326	register struct shmid_ds *shp;
	327
	328	shp = &shmsegs[mp->mm_id % SHMMMNI];
	329	if (off >= ctob(clrnd(btoc(shp->shm_segsz))))
	330	return(-1);
	331	return(((struct pte *)shp->shm_handle)[btop(off)].pg_pfnum);
	332	}
	333
	334	/*
	335	* Increment attach count on fork
	336	*/
6be55866	337	/* ARGSUSED */
6f843dc9 KM	338	shmfork(mp, ischild)
	339	register struct mapmem *mp;
	340	{
	341	if (!ischild)
	342	shmsegs[mp->mm_id % SHMMMNI].shm_nattch++;
	343	}
	344
	345	/*
	346	* Detach from shared memory segment on exit (or exec)
	347	*/
015c074c	348	shmexit(mp)
6be55866	349	struct mapmem *mp;
6f843dc9	350	{
015c074c	351	struct proc p = u.u_procp; / XXX */
c9714ae3	352
161c14a2	353	return (shmufree(p, mp));
6f843dc9 KM	354	}
	355
	356	shmvalid(id)
	357	register int id;
	358	{
	359	register struct shmid_ds *shp;
	360
	361	if (id < 0 \|\| (id % SHMMMNI) >= shminfo.shmmni)
161c14a2	362	return(EINVAL);
6f843dc9 KM	363	shp = &shmsegs[id % SHMMMNI];
	364	if (shp->shm_perm.seq == (id / SHMMMNI) &&
	365	(shp->shm_perm.mode & (SHM_ALLOC\|SHM_DEST)) == SHM_ALLOC)
161c14a2 KM	366	return(0);
161c14a2 KM	367	return(EINVAL);
6f843dc9 KM	368	}
	369
	370	/*
	371	* Free user resources associated with a shared memory segment
	372	*/
c9714ae3 KM	373	shmufree(p, mp)
c9714ae3 KM	374	struct proc *p;
6f843dc9 KM	375	struct mapmem *mp;
	376	{
	377	register struct shmid_ds *shp;
c9714ae3	378	int error;
6f843dc9 KM	379
6f843dc9 KM	380	shp = &shmsegs[mp->mm_id % SHMMMNI];
c9714ae3 KM	381	mmmapout(p, mp);
c9714ae3 KM	382	error = mmfree(p, mp);
6f843dc9 KM	383	shp->shm_dtime = time.tv_sec;
	384	if (--shp->shm_nattch <= 0 && (shp->shm_perm.mode & SHM_DEST))
	385	shmfree(shp);
c9714ae3	386	return (error);
6f843dc9 KM	387	}
	388
	389	/*
	390	* Deallocate resources associated with a shared memory segment
	391	*/
	392	shmfree(shp)
	393	register struct shmid_ds *shp;
	394	{
	395	caddr_t kva;
	396
	397	if (shp->shm_handle == NULL)
	398	panic("shmfree");
	399	kva = (caddr_t) ptetokv(shp->shm_handle);
	400	free(kva, M_SHM);
	401	shp->shm_handle = NULL;
	402	shmtot -= clrnd(btoc(shp->shm_segsz));
	403	shp->shm_perm.mode = 0;
	404	/*
	405	* Increment the sequence number to ensure that outstanding
	406	* shmids for this segment will be invalid in the event that
	407	* the segment is reallocated. Note that shmids must be
	408	* positive as decreed by SVID.
	409	*/
	410	shp->shm_perm.seq++;
	411	if ((int)(shp->shm_perm.seq * SHMMMNI) < 0)
	412	shp->shm_perm.seq = 0;
	413	}
	414
	415	/*
	416	* XXX This routine would be common to all sysV style IPC
	417	* (if the others were implemented).
	418	*/
161c14a2	419	ipcaccess(ipc, mode, cred)
6f843dc9	420	register struct ipc_perm *ipc;
161c14a2 KM	421	int mode;
161c14a2 KM	422	register struct ucred *cred;
6f843dc9 KM	423	{
	424	register int m;
	425
161c14a2	426	if (cred->cr_uid == 0)
6f843dc9 KM	427	return(0);
	428	/*
	429	* Access check is based on only one of owner, group, public.
	430	* If not owner, then check group.
	431	* If not a member of the group, then check public access.
	432	*/
	433	mode &= 0700;
	434	m = ipc->mode;
161c14a2	435	if (cred->cr_uid != ipc->uid && cred->cr_uid != ipc->cuid) {
6f843dc9	436	m <<= 3;
161c14a2 KM	437	if (!groupmember(ipc->gid, cred) &&
161c14a2 KM	438	!groupmember(ipc->cgid, cred))
6f843dc9 KM	439	m <<= 3;
	440	}
	441	if ((mode&m) == mode)
161c14a2 KM	442	return (0);
161c14a2 KM	443	return (EACCES);
6f843dc9 KM	444	}
	445
	446	#endif /* SYSVSHM */