]> git.saurik.com Git - apple/xnu.git/blobdiff - bsd/kern/posix_shm.c
xnu-3247.1.106.tar.gz
[apple/xnu.git] / bsd / kern / posix_shm.c
index 1b25d26acff19d6e1c96ad70a1c6b80b3d38bc29..e14baf815e932decbe39ea8506c53805c35e514a 100644 (file)
@@ -1,23 +1,29 @@
 /*
- * Copyright (c) 2000-2002 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2000-2007 Apple Inc. All rights reserved.
  *
- * @APPLE_LICENSE_HEADER_START@
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
  * 
- * The contents of this file constitute Original Code as defined in and
- * are subject to the Apple Public Source License Version 1.1 (the
- * "License").  You may not use this file except in compliance with the
- * License.  Please obtain a copy of the License at
- * http://www.apple.com/publicsource and read it before using this file.
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. The rights granted to you under the License
+ * may not be used to create, or enable the creation or redistribution of,
+ * unlawful or unlicensed copies of an Apple operating system, or to
+ * circumvent, violate, or enable the circumvention or violation of, any
+ * terms of an Apple operating system software license agreement.
  * 
- * This Original Code and all software distributed under the License are
- * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this file.
+ * 
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
- * License for the specific language governing rights and limitations
- * under the License.
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
  * 
- * @APPLE_LICENSE_HEADER_END@
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  */
 /*
  *     Copyright (c) 1990, 1996-1998 Apple Computer, Inc.
  *     Created for MacOSX
  *
  */
+/*
+ * NOTICE: This file was modified by SPARTA, Inc. in 2005 to introduce
+ * support for mandatory and extensible security protections.  This notice
+ * is included in support of clause 2.2 (b) of the Apple Public License,
+ * Version 2.0.
+ */
 
 #include <sys/cdefs.h>
 #include <sys/param.h>
 #include <sys/systm.h>
 #include <sys/kernel.h>
-#include <sys/file.h>
+#include <sys/file_internal.h>
 #include <sys/filedesc.h>
 #include <sys/stat.h>
-#include <sys/buf.h>
-#include <sys/proc.h>
+#include <sys/proc_internal.h>
+#include <sys/kauth.h>
 #include <sys/mount.h>
 #include <sys/namei.h>
 #include <sys/vnode.h>
+#include <sys/vnode_internal.h>
 #include <sys/ioctl.h>
 #include <sys/tty.h>
 #include <sys/malloc.h>
 #include <sys/mman.h>
 #include <sys/stat.h>
+#include <sys/sysproto.h>
+#include <sys/proc_info.h>
+#include <security/audit/audit.h>
+
+#if CONFIG_MACF
+#include <security/mac_framework.h>
+#endif
+
 #include <mach/mach_types.h>
+#include <mach/mach_vm.h>
+#include <mach/vm_map.h>
 #include <mach/vm_prot.h>
 #include <mach/vm_inherit.h>
 #include <mach/kern_return.h>
 #include <mach/memory_object_control.h>
 
+#include <vm/vm_map.h>
+#include <vm/vm_protos.h>
 
+#define f_flag f_fglob->fg_flag
+#define f_type f_fglob->fg_ops->fo_type
+#define f_msgcount f_fglob->fg_msgcount
+#define f_cred f_fglob->fg_cred
+#define f_ops f_fglob->fg_ops
+#define f_offset f_fglob->fg_offset
+#define f_data f_fglob->fg_data
 #define        PSHMNAMLEN      31      /* maximum name segment length we bother with */
 
+struct pshmobj {
+       void *                  pshmo_memobject;
+       memory_object_size_t    pshmo_size;
+       struct pshmobj *        pshmo_next;
+};
+
 struct pshminfo {
        unsigned int    pshm_flags;
        unsigned int    pshm_usecount;
@@ -69,23 +107,25 @@ struct pshminfo {
        uid_t           pshm_uid;
        gid_t           pshm_gid;
        char            pshm_name[PSHMNAMLEN + 1];      /* segment name */
-       void *          pshm_memobject;
+       struct pshmobj *pshm_memobjects;
 #if DIAGNOSTIC
        unsigned int    pshm_readcount;
        unsigned int    pshm_writecount;
-       struct proc *   pshm_proc;
+       proc_t          pshm_proc;
 #endif /* DIAGNOSTIC */
+       struct label*   pshm_label;
 };
 #define PSHMINFO_NULL (struct pshminfo *)0
 
-#define        PSHM_NONE       1
-#define        PSHM_DEFINED    2
-#define        PSHM_ALLOCATED  4
-#define        PSHM_MAPPED     8
-#define        PSHM_INUSE      0x10
-#define        PSHM_REMOVED    0x20
-#define        PSHM_INCREATE   0x40
-#define        PSHM_INDELETE   0x80
+#define        PSHM_NONE       0x001
+#define        PSHM_DEFINED    0x002
+#define        PSHM_ALLOCATED  0x004
+#define        PSHM_MAPPED     0x008
+#define        PSHM_INUSE      0x010
+#define        PSHM_REMOVED    0x020
+#define        PSHM_INCREATE   0x040
+#define        PSHM_INDELETE   0x080
+#define PSHM_ALLOCATING        0x100
 
 struct pshmcache {
        LIST_ENTRY(pshmcache) pshm_hash;        /* hash chain */
@@ -111,8 +151,8 @@ struct pshmname {
 };
 
 struct pshmnode {
-       off_t  mapp_addr;
-       size_t  map_size;
+       off_t           mapp_addr;
+       user_size_t     map_size;       /* XXX unused ? */
        struct pshminfo *pinfo;
        unsigned int    pshm_usecount;
 #if DIAGNOSTIC
@@ -125,23 +165,65 @@ struct pshmnode {
 
 #define PSHMHASH(pnp) \
        (&pshmhashtbl[(pnp)->pshm_hash & pshmhash])
+
 LIST_HEAD(pshmhashhead, pshmcache) *pshmhashtbl;       /* Hash Table */
 u_long pshmhash;                               /* size of hash table - 1 */
 long   pshmnument;                     /* number of cache entries allocated */
 struct pshmstats pshmstats;            /* cache effectiveness statistics */
 
-static int pshm_read  __P((struct file *fp, struct uio *uio,
-                   struct ucred *cred, int flags, struct proc *p));
-static int pshm_write  __P((struct file *fp, struct uio *uio,
-                   struct ucred *cred, int flags, struct proc *p));
-static int pshm_ioctl  __P((struct file *fp, u_long com,
-                   caddr_t data, struct proc *p));
-static int pshm_select  __P((struct file *fp, int which, void *wql,
-                   struct proc *p));
-static int pshm_closefile  __P((struct file *fp, struct proc *p));
+static int pshm_read (struct fileproc *fp, struct uio *uio,
+                   int flags, vfs_context_t ctx);
+static int pshm_write (struct fileproc *fp, struct uio *uio,
+                   int flags, vfs_context_t ctx);
+static int pshm_ioctl (struct fileproc *fp, u_long com,
+                   caddr_t data, vfs_context_t ctx);
+static int pshm_select (struct fileproc *fp, int which, void *wql, vfs_context_t ctx);
+static int pshm_close(struct pshminfo *pinfo, int dropref);
+static int pshm_closefile (struct fileglob *fg, vfs_context_t ctx);
+
+static int pshm_kqfilter(struct fileproc *fp, struct knote *kn, vfs_context_t ctx);
+
+int pshm_access(struct pshminfo *pinfo, int mode, kauth_cred_t cred, proc_t p);
+static int pshm_cache_add(struct pshminfo *pshmp, struct pshmname *pnp, struct pshmcache *pcp);
+static void pshm_cache_delete(struct pshmcache *pcp);
+#if NOT_USED
+static void pshm_cache_purge(void);
+#endif /* NOT_USED */
+static int pshm_cache_search(struct pshminfo **pshmp, struct pshmname *pnp,
+       struct pshmcache **pcache, int addref);
+
+static const struct fileops pshmops = {
+       DTYPE_PSXSHM,
+       pshm_read,
+       pshm_write,
+       pshm_ioctl,
+       pshm_select,
+       pshm_closefile,
+       pshm_kqfilter,
+       0
+};
+
+static lck_grp_t       *psx_shm_subsys_lck_grp;
+static lck_grp_attr_t  *psx_shm_subsys_lck_grp_attr;
+static lck_attr_t      *psx_shm_subsys_lck_attr;
+static lck_mtx_t        psx_shm_subsys_mutex;
+
+#define PSHM_SUBSYS_LOCK() lck_mtx_lock(& psx_shm_subsys_mutex)
+#define PSHM_SUBSYS_UNLOCK() lck_mtx_unlock(& psx_shm_subsys_mutex)
+
+
+/* Initialize the mutex governing access to the posix shm subsystem */
+__private_extern__ void
+pshm_lock_init( void )
+{
+
+    psx_shm_subsys_lck_grp_attr = lck_grp_attr_alloc_init();
 
-struct         fileops pshmops =
-       { pshm_read, pshm_write, pshm_ioctl, pshm_select, pshm_closefile };
+    psx_shm_subsys_lck_grp = lck_grp_alloc_init("posix shared memory", psx_shm_subsys_lck_grp_attr);
+
+    psx_shm_subsys_lck_attr = lck_attr_alloc_init();
+    lck_mtx_init(& psx_shm_subsys_mutex, psx_shm_subsys_lck_grp, psx_shm_subsys_lck_attr);
+}
 
 /*
  * Lookup an entry in the cache 
@@ -153,14 +235,12 @@ struct    fileops pshmops =
  * fails, a status of zero is returned.
  */
 
-int
-pshm_cache_search(pshmp, pnp, pcache)
-       struct pshminfo **pshmp;
-       struct pshmname *pnp;
-       struct pshmcache **pcache;
+static int
+pshm_cache_search(struct pshminfo **pshmp, struct pshmname *pnp,
+       struct pshmcache **pcache, int addref)
 {
-       register struct pshmcache *pcp, *nnp;
-       register struct pshmhashhead *pcpp;
+       struct pshmcache *pcp, *nnp;
+       struct pshmhashhead *pcpp;
 
        if (pnp->pshm_namelen > PSHMNAMLEN) {
                pshmstats.longnames++;
@@ -186,12 +266,13 @@ pshm_cache_search(pshmp, pnp, pcache)
                /* TOUCH(ncp); */
                *pshmp = pcp->pshminfo;
                *pcache = pcp;
+               if (addref)
+                       pcp->pshminfo->pshm_usecount++;
                return (-1);
        }
 
        /*
         * We found a "negative" match, ENOENT notifies client of this match.
-        * The nc_vpid field records whether this is a whiteout.
         */
        pshmstats.neghits++;
        return (ENOENT);
@@ -199,41 +280,29 @@ pshm_cache_search(pshmp, pnp, pcache)
 
 /*
  * Add an entry to the cache.
+ * XXX should be static?
  */
-int
-pshm_cache_add(pshmp, pnp)
-       struct pshminfo *pshmp;
-       struct pshmname *pnp;
+static int
+pshm_cache_add(struct pshminfo *pshmp, struct pshmname *pnp, struct pshmcache *pcp)
 {
-       register struct pshmcache *pcp;
-       register struct pshmhashhead *pcpp;
-       register struct pshminfo *dpinfo;
-       register struct pshmcache *dpcp;
+       struct pshmhashhead *pcpp;
+       struct pshminfo *dpinfo;
+       struct pshmcache *dpcp;
 
 #if DIAGNOSTIC
-       if (pnp->pshm_namelen > NCHNAMLEN)
+       if (pnp->pshm_namelen > PSHMNAMLEN)
                panic("cache_enter: name too long");
 #endif
 
-       /*
-        * We allocate a new entry if we are less than the maximum
-        * allowed and the one at the front of the LRU list is in use.
-        * Otherwise we use the one at the front of the LRU list.
-        */
-       pcp = (struct pshmcache *)_MALLOC(sizeof(struct pshmcache), M_SHM, M_WAITOK);
+
        /*  if the entry has already been added by some one else return */
-       if (pshm_cache_search(&dpinfo, pnp, &dpcp) == -1) {
-               _FREE(pcp, M_SHM);
+       if (pshm_cache_search(&dpinfo, pnp, &dpcp, 0) == -1) {
                return(EEXIST);
        }
        pshmnument++;
 
-       bzero(pcp, sizeof(struct pshmcache));
        /*
         * Fill in cache info, if vp is NULL this is a "negative" cache entry.
-        * For negative entries, we have to record whether it is a whiteout.
-        * the whiteout flag is stored in the nc_vpid field which is
-        * otherwise unused.
         */
        pcp->pshminfo = pshmp;
        pcp->pshm_nlen = pnp->pshm_namelen;
@@ -241,7 +310,7 @@ pshm_cache_add(pshmp, pnp)
        pcpp = PSHMHASH(pnp);
 #if DIAGNOSTIC
        {
-               register struct pshmcache *p;
+               struct pshmcache *p;
 
                for (p = pcpp->lh_first; p != 0; p = p->pshm_hash.le_next)
                        if (p == pcp)
@@ -256,11 +325,12 @@ pshm_cache_add(pshmp, pnp)
  * Name cache initialization, from vfs_init() when we are booting
  */
 void
-pshm_cache_init()
+pshm_cache_init(void)
 {
-       pshmhashtbl = hashinit(desiredvnodes, M_SHM, &pshmhash);
+       pshmhashtbl = hashinit(desiredvnodes / 8, M_SHM, &pshmhash);
 }
 
+#if NOT_USED
 /*
  * Invalidate a all entries to particular vnode.
  * 
@@ -269,20 +339,21 @@ pshm_cache_init()
  * need to ditch the entire cache, to avoid confusion. No valid vnode will
  * ever have (v_id == 0).
  */
-void
+static void
 pshm_cache_purge(void)
 {
        struct pshmcache *pcp;
        struct pshmhashhead *pcpp;
 
        for (pcpp = &pshmhashtbl[pshmhash]; pcpp >= pshmhashtbl; pcpp--) {
-               while (pcp = pcpp->lh_first)
+               while ( (pcp = pcpp->lh_first) )
                        pshm_cache_delete(pcp);
        }
 }
+#endif /* NOT_USED */
 
-pshm_cache_delete(pcp)
-       struct pshmcache *pcp;
+static void
+pshm_cache_delete(struct pshmcache *pcp)
 {
 #if DIAGNOSTIC
        if (pcp->pshm_hash.le_prev == 0)
@@ -296,55 +367,51 @@ pshm_cache_delete(pcp)
 }
 
 
-struct shm_open_args {
-       const char *name;
-       int oflag;
-       int mode;
-};
-
 int
-shm_open(p, uap, retval)
-       struct proc *p;
-       register struct shm_open_args *uap;
-       register_t *retval;
+shm_open(proc_t p, struct shm_open_args *uap, int32_t *retval)
 {
-       register struct filedesc *fdp = p->p_fd;
-       register struct file *fp;
-       register struct vnode *vp;
-       int  i;
-       struct file *nfp;
-       int type, indx, error;
+       size_t  i;
+       int indx, error;
        struct pshmname nd;
        struct pshminfo *pinfo;
-       extern struct fileops pshmops;
-       char * pnbuf;
+       struct fileproc *fp = NULL;
+       char *pnbuf = NULL;
+       struct pshminfo *new_pinfo = PSHMINFO_NULL;
+       struct pshmnode *new_pnode = PSHMNODE_NULL;
+       struct pshmcache *pcache = PSHMCACHE_NULL;      /* ignored on return */
        char * nameptr;
        char * cp;
        size_t pathlen, plen;
        int fmode ;
        int cmode = uap->mode;
        int incache = 0;
-       struct pshmnode * pnode = PSHMNODE_NULL;
-       struct pshmcache * pcache = PSHMCACHE_NULL;
-       int pinfo_alloc=0;
+       struct pshmcache *pcp = NULL;
 
+       AUDIT_ARG(fflags, uap->oflag);
+       AUDIT_ARG(mode, uap->mode);
 
        pinfo = PSHMINFO_NULL;
 
-       MALLOC_ZONE(pnbuf, caddr_t,
-                       MAXPATHLEN, M_NAMEI, M_WAITOK);
+       /*
+        * Preallocate everything we might need up front to avoid taking
+        * and dropping the lock, opening us up to race conditions.
+        */
+       MALLOC_ZONE(pnbuf, caddr_t, MAXPATHLEN, M_NAMEI, M_WAITOK);
+       if (pnbuf == NULL) {
+               error = ENOSPC;
+               goto bad;
+       }
+
        pathlen = MAXPATHLEN;
-       error = copyinstr(uap->name, pnbuf,
-               MAXPATHLEN, &pathlen);
+       error = copyinstr(uap->name, (void *)pnbuf, MAXPATHLEN, &pathlen);
        if (error) {
                goto bad;
        }
+       AUDIT_ARG(text, pnbuf);
        if (pathlen > PSHMNAMLEN) {
                error = ENAMETOOLONG;
                goto bad;
        }
-
-
 #ifdef PSXSHM_NAME_RESTRICT
        nameptr = pnbuf;
        if (*nameptr == '/') {
@@ -353,7 +420,7 @@ shm_open(p, uap, retval)
                        error = EINVAL;
                        goto bad;
                }
-        } else {
+       } else {
                error = EINVAL;
                goto bad;
        }
@@ -365,132 +432,247 @@ shm_open(p, uap, retval)
        nd.pshm_namelen = plen;
        nd. pshm_hash =0;
 
-        for (cp = nameptr, i=1; *cp != 0 && i <= plen; i++, cp++) {
-               nd.pshm_hash += (unsigned char)*cp * i;
+       for (cp = nameptr, i=1; *cp != 0 && i <= plen; i++, cp++) {
+               nd.pshm_hash += (unsigned char)*cp * i;
        }
 
-       error = pshm_cache_search(&pinfo, &nd, &pcache);
+       /*
+        * attempt to allocate a new fp; if unsuccessful, the fp will be
+        * left unmodified (NULL).
+        */
+       error = falloc(p, &fp, &indx, vfs_context_current());
+       if (error) 
+               goto bad;
+
+       cmode &=  ALLPERMS;
 
-       if (error == ENOENT) {
+       fmode = FFLAGS(uap->oflag);
+       if ((fmode & (FREAD | FWRITE)) == 0) {
                error = EINVAL;
                goto bad;
+       }
 
+       /*
+        * We allocate a new entry if we are less than the maximum
+        * allowed and the one at the front of the LRU list is in use.
+        * Otherwise we use the one at the front of the LRU list.
+        */
+       MALLOC(pcp, struct pshmcache *, sizeof(struct pshmcache), M_SHM, M_WAITOK|M_ZERO);
+       if (pcp == NULL) {
+               error = ENOSPC;
+               goto bad;
        }
-       if (!error) {
-               incache = 0;
-       } else
-               incache = 1;
-       fmode = FFLAGS(uap->oflag);
-       if ((fmode & (FREAD | FWRITE))==0)
-               return(EINVAL);
 
-       if (error = falloc(p, &nfp, &indx))
-               return (error);
-       fp = nfp;
+       MALLOC(new_pinfo, struct pshminfo *, sizeof(struct pshminfo), M_SHM, M_WAITOK|M_ZERO);
+       if (new_pinfo == PSHMINFO_NULL) {
+               error = ENOSPC;
+               goto bad;
+       }
+#if CONFIG_MACF
+       mac_posixshm_label_init(new_pinfo);
+#endif
 
-       cmode &=  ALLPERMS;
+       MALLOC(new_pnode, struct pshmnode *, sizeof(struct pshmnode), M_SHM, M_WAITOK|M_ZERO);
+       if (new_pnode == PSHMNODE_NULL) {
+               error = ENOSPC;
+               goto bad;
+       }
+
+       PSHM_SUBSYS_LOCK();
+
+       /*
+        * If we find the entry in the cache, this will take a reference,
+        * allowing us to unlock it for the permissions check.
+        */
+       error = pshm_cache_search(&pinfo, &nd, &pcache, 1);
+
+       PSHM_SUBSYS_UNLOCK();
+
+       if (error == ENOENT) {
+               error = EINVAL;
+               goto bad;
+       }
 
-       if (fmode & O_CREAT) {
-               if ((fmode & O_EXCL) && incache) {
-                       /* shm obj exists and opened O_EXCL */
-#if notyet
-                        if (pinfo->pshm_flags & PSHM_INDELETE) {
-                        }
-#endif 
-                        error = EEXIST;
-                        goto bad1;
-                } 
-                if (!incache) {
-                    /*  create a new one */
-                    pinfo = (struct pshminfo *)_MALLOC(sizeof(struct pshminfo), M_SHM, M_WAITOK);
-                    bzero(pinfo, sizeof(struct pshminfo));
-                       pinfo_alloc = 1;
-                    pinfo->pshm_flags = PSHM_DEFINED | PSHM_INCREATE;
-                    pinfo->pshm_usecount = 1;
-                    pinfo->pshm_mode = cmode;
-                    pinfo->pshm_uid = p->p_ucred->cr_uid;
-                    pinfo->pshm_gid = p->p_ucred->cr_gid;
-                } else {
-                    /*  already exists */
-                        if( pinfo->pshm_flags & PSHM_INDELETE) {
-                            error = ENOENT;
-                            goto bad1;
-                        }      
-                        if (error = pshm_access(pinfo, fmode, p->p_ucred, p))
-                            goto bad1;
-                }
+       if (!error) {
+               incache = 0;
+               if (fmode & O_CREAT) {
+                       /*  create a new one (commit the allocation) */
+                       pinfo = new_pinfo;
+                       pinfo->pshm_flags = PSHM_DEFINED | PSHM_INCREATE;
+                       pinfo->pshm_usecount = 1; /* existence reference */
+                       pinfo->pshm_mode = cmode;
+                       pinfo->pshm_uid = kauth_getuid();
+                       pinfo->pshm_gid = kauth_getgid();
+                       bcopy(pnbuf, &pinfo->pshm_name[0], pathlen);
+                       pinfo->pshm_name[pathlen]=0;
+#if CONFIG_MACF
+                       error = mac_posixshm_check_create(kauth_cred_get(), nameptr);
+                       if (error) {
+                               goto bad;
+                       }
+                       mac_posixshm_label_associate(kauth_cred_get(), pinfo, nameptr);
+#endif
+               }
        } else {
+               incache = 1;
+               if (fmode & O_CREAT) {
+                       /*  already exists */
+                       if ((fmode & O_EXCL)) {
+                               AUDIT_ARG(posix_ipc_perm, pinfo->pshm_uid,
+                                               pinfo->pshm_gid,
+                                               pinfo->pshm_mode);
+
+                               /* shm obj exists and opened O_EXCL */
+                               error = EEXIST;
+                               goto bad;
+                       } 
+
+                       if( pinfo->pshm_flags & PSHM_INDELETE) {
+                               error = ENOENT;
+                               goto bad;
+                       }       
+                       AUDIT_ARG(posix_ipc_perm, pinfo->pshm_uid,
+                                       pinfo->pshm_gid, pinfo->pshm_mode);
+#if CONFIG_MACF        
+                       if ((error = mac_posixshm_check_open(kauth_cred_get(), pinfo, fmode))) {
+                               goto bad;
+                       }
+#endif
+                       if ( (error = pshm_access(pinfo, fmode, kauth_cred_get(), p)) ) {
+                               goto bad;
+                       }
+               }
+       }
+       if (!(fmode & O_CREAT)) {
                if (!incache) {
-                       /* O_CREAT  is not set and the shm obecj does not exist */
+                       /* O_CREAT is not set and the object does not exist */
                        error = ENOENT;
-                       goto bad1;
+                       goto bad;
                }
                if( pinfo->pshm_flags & PSHM_INDELETE) {
                        error = ENOENT;
-                       goto bad1;
+                       goto bad;
                }       
-               if (error = pshm_access(pinfo, fmode, p->p_ucred, p))
-                       goto bad1;
+#if CONFIG_MACF        
+               if ((error = mac_posixshm_check_open(kauth_cred_get(), pinfo, fmode))) {
+                       goto bad;
+               }
+#endif
+
+               if ((error = pshm_access(pinfo, fmode, kauth_cred_get(), p))) {
+                       goto bad;
+               }
        }
        if (fmode & O_TRUNC) {
                error = EINVAL;
-               goto bad2;
+               goto bad;
        }
+
+
+       PSHM_SUBSYS_LOCK();
+
 #if DIAGNOSTIC 
        if (fmode & FWRITE)
                pinfo->pshm_writecount++;
        if (fmode & FREAD)
                pinfo->pshm_readcount++;
 #endif
-       pnode = (struct pshmnode *)_MALLOC(sizeof(struct pshmnode), M_SHM, M_WAITOK);
-       bzero(pnode, sizeof(struct pshmnode));
-
        if (!incache) {
-               if (error = pshm_cache_add(pinfo, &nd)) {
-               goto bad3;
+               /* if successful, this will consume the pcp */
+               if ( (error = pshm_cache_add(pinfo, &nd, pcp)) ) {
+                       goto bad_locked;
                }
+               /*
+                * add reference for the new entry; otherwise, we obtained
+                * one from the cache hit earlier.
+                */
+               pinfo->pshm_usecount++;
        }
        pinfo->pshm_flags &= ~PSHM_INCREATE;
-       pinfo->pshm_usecount++;
-       pnode->pinfo = pinfo;
+       new_pnode->pinfo = pinfo;
+
+       PSHM_SUBSYS_UNLOCK();
+
+       /*
+        * if incache, we did not use the new pcp or new_pinfo and must
+        * free them
+        */
+       if (incache) {
+               FREE(pcp, M_SHM);
+
+               if (new_pinfo != PSHMINFO_NULL) {
+#if CONFIG_MACF
+                       mac_posixshm_label_destroy(new_pinfo);
+#endif
+                       FREE(new_pinfo, M_SHM);
+               }
+       }
+
+       proc_fdlock(p);
        fp->f_flag = fmode & FMASK;
-       fp->f_type = DTYPE_PSXSHM;
        fp->f_ops = &pshmops;
-       fp->f_data = (caddr_t)pnode;
-       *fdflags(p, indx) &= ~UF_RESERVED;
+       fp->f_data = (caddr_t)new_pnode;
+       *fdflags(p, indx) |= UF_EXCLOSE;
+       procfdtbl_releasefd(p, indx, NULL);
+       fp_drop(p, indx, fp, 1);
+       proc_fdunlock(p);
+
        *retval = indx;
-       _FREE_ZONE(pnbuf, MAXPATHLEN, M_NAMEI);
+       FREE_ZONE(pnbuf, MAXPATHLEN, M_NAMEI);
        return (0);
-bad3:
-       _FREE(pnode, M_SHM);
-               
-bad2:
-       if (pinfo_alloc)
-               _FREE(pinfo, M_SHM);
-bad1:
-       fdrelse(p, indx);
-       ffree(nfp);
+
+bad_locked:
+       PSHM_SUBSYS_UNLOCK();
 bad:
-       _FREE_ZONE(pnbuf, MAXPATHLEN, M_NAMEI);
+       /*
+        * If we obtained the entry from the cache, we need to drop the
+        * reference; holding the reference may have prevented unlinking,
+        * so we need to call pshm_close() to get the full effect.
+        */
+       if (incache) {
+               PSHM_SUBSYS_LOCK();
+               pshm_close(pinfo, 1);
+               PSHM_SUBSYS_UNLOCK();
+       }
+
+       if (pcp != NULL)
+               FREE(pcp, M_SHM);
+
+       if (new_pnode != PSHMNODE_NULL)
+               FREE(new_pnode, M_SHM);
+
+       if (fp != NULL)
+               fp_free(p, indx, fp);
+
+       if (new_pinfo != PSHMINFO_NULL) {
+#if CONFIG_MACF
+               mac_posixshm_label_destroy(new_pinfo);
+#endif
+               FREE(new_pinfo, M_SHM);
+       }
+       if (pnbuf != NULL)
+               FREE_ZONE(pnbuf, MAXPATHLEN, M_NAMEI);
        return (error);
 }
 
 
-/* ARGSUSED */
 int
-pshm_truncate(p, fp, fd, length, retval)
-       struct proc *p;
-       struct file *fp;
-       int fd;
-       off_t length;
-       register_t *retval;
+pshm_truncate(__unused proc_t p, struct fileproc *fp, __unused int fd, 
+                               off_t length, __unused int32_t *retval)
 {
        struct pshminfo * pinfo;
        struct pshmnode * pnode ;
        kern_return_t kret;
-       vm_offset_t user_addr;
-       void * mem_object;
-       vm_size_t size;
+       mem_entry_name_port_t mem_object;
+       mach_vm_size_t total_size, alloc_size;
+       memory_object_size_t mosize;
+       struct pshmobj *pshmobj, *pshmobj_next, **pshmobj_next_p;
+       vm_map_t        user_map;
+#if CONFIG_MACF
+       int error;
+#endif
+
+       user_map = current_map();
 
        if (fp->f_type != DTYPE_PSXSHM) {
                return(EINVAL);
@@ -500,33 +682,85 @@ pshm_truncate(p, fp, fd, length, retval)
        if (((pnode = (struct pshmnode *)fp->f_data)) == PSHMNODE_NULL )
                return(EINVAL);
 
-       if ((pinfo = pnode->pinfo) == PSHMINFO_NULL)
+       PSHM_SUBSYS_LOCK();
+       if ((pinfo = pnode->pinfo) == PSHMINFO_NULL) {
+               PSHM_SUBSYS_UNLOCK();
                return(EINVAL);
-       if ((pinfo->pshm_flags & (PSHM_DEFINED | PSHM_ALLOCATED)) 
+       }
+       if ((pinfo->pshm_flags & (PSHM_DEFINED|PSHM_ALLOCATING|PSHM_ALLOCATED)) 
                        != PSHM_DEFINED) {
+               PSHM_SUBSYS_UNLOCK();
                return(EINVAL);
        }
+#if CONFIG_MACF
+       error = mac_posixshm_check_truncate(kauth_cred_get(), pinfo, length);
+       if (error) {
+               PSHM_SUBSYS_UNLOCK();
+               return(error);
+       }
+#endif
 
-       size = round_page (length);
-       kret = vm_allocate(current_map(), &user_addr, size, TRUE);
-       if (kret != KERN_SUCCESS) 
-               goto out;
+       pinfo->pshm_flags |= PSHM_ALLOCATING;
+       total_size = vm_map_round_page(length,
+                                      vm_map_page_mask(user_map));
+       pshmobj_next_p = &pinfo->pshm_memobjects;
 
-       kret = mach_make_memory_entry (current_map(), &size,
-                       user_addr, VM_PROT_DEFAULT, &mem_object, 0);
+       for (alloc_size = 0;
+            alloc_size < total_size;
+            alloc_size += mosize) {
 
-       if (kret != KERN_SUCCESS) 
-               goto out;
-       
-       vm_deallocate(current_map(), user_addr, size);
+               PSHM_SUBSYS_UNLOCK();
+
+               mosize = MIN(total_size - alloc_size, ANON_MAX_SIZE);
+               kret = mach_make_memory_entry_64(
+                       VM_MAP_NULL,
+                       &mosize,
+                       0,
+                       MAP_MEM_NAMED_CREATE | VM_PROT_DEFAULT,
+                       &mem_object,
+                       0);
 
-       pinfo->pshm_flags &= ~PSHM_DEFINED;
-       pinfo->pshm_flags = PSHM_ALLOCATED;
-       pinfo->pshm_memobject = mem_object;
-       pinfo->pshm_length = size;
+               if (kret != KERN_SUCCESS) 
+                       goto out;
+
+               MALLOC(pshmobj, struct pshmobj *, sizeof (struct pshmobj),
+                      M_SHM, M_WAITOK);
+               if (pshmobj == NULL) {
+                       kret = KERN_NO_SPACE;
+                       mach_memory_entry_port_release(mem_object);
+                       mem_object = NULL;
+                       goto out;
+               }
+
+               PSHM_SUBSYS_LOCK();
+
+               pshmobj->pshmo_memobject = (void *) mem_object;
+               pshmobj->pshmo_size = mosize;
+               pshmobj->pshmo_next = NULL;
+               
+               *pshmobj_next_p = pshmobj;
+               pshmobj_next_p = &pshmobj->pshmo_next;
+       }
+       
+       pinfo->pshm_flags |= PSHM_ALLOCATED;
+       pinfo->pshm_flags &= ~(PSHM_ALLOCATING);
+       pinfo->pshm_length = total_size;
+       PSHM_SUBSYS_UNLOCK();
        return(0);
 
 out:
+       PSHM_SUBSYS_LOCK();
+       for (pshmobj = pinfo->pshm_memobjects;
+            pshmobj != NULL;
+            pshmobj = pshmobj_next) {
+               pshmobj_next = pshmobj->pshmo_next;
+               mach_memory_entry_port_release(pshmobj->pshmo_memobject);
+               FREE(pshmobj, M_SHM);
+       }
+       pinfo->pshm_memobjects = NULL;
+       pinfo->pshm_flags &= ~PSHM_ALLOCATING;
+       PSHM_SUBSYS_UNLOCK();
+
        switch (kret) {
        case KERN_INVALID_ADDRESS:
        case KERN_NO_SPACE:
@@ -540,91 +774,87 @@ out:
 }
 
 int
-pshm_stat(pnode, sb)
-struct pshmnode *pnode;
-struct stat *sb;
+pshm_stat(struct pshmnode *pnode, void *ub, int isstat64)
 {
+       struct stat *sb = (struct stat *)0;     /* warning avoidance ; protected by isstat64 */
+       struct stat64 * sb64 = (struct stat64 *)0;  /* warning avoidance ; protected by isstat64 */
        struct pshminfo *pinfo;
+#if CONFIG_MACF
+       int error;
+#endif
        
-       if ((pinfo = pnode->pinfo) == PSHMINFO_NULL)
+       PSHM_SUBSYS_LOCK();
+       if ((pinfo = pnode->pinfo) == PSHMINFO_NULL){
+               PSHM_SUBSYS_UNLOCK();
                return(EINVAL);
+       }
+
+#if CONFIG_MACF
+       error = mac_posixshm_check_stat(kauth_cred_get(), pinfo);
+       if (error) {
+               PSHM_SUBSYS_UNLOCK();
+               return(error);
+       }
+#endif
 
-       bzero(sb, sizeof(struct stat)); 
-       sb->st_mode = pinfo->pshm_mode;
-       sb->st_uid = pinfo->pshm_uid;
-       sb->st_gid = pinfo->pshm_gid;
-       sb->st_size = pinfo->pshm_length;
+       if (isstat64 != 0) {
+               sb64 = (struct stat64 *)ub;
+               bzero(sb64, sizeof(struct stat64)); 
+               sb64->st_mode = pinfo->pshm_mode;
+               sb64->st_uid = pinfo->pshm_uid;
+               sb64->st_gid = pinfo->pshm_gid;
+               sb64->st_size = pinfo->pshm_length;
+       } else {
+               sb = (struct stat *)ub;
+               bzero(sb, sizeof(struct stat)); 
+               sb->st_mode = pinfo->pshm_mode;
+               sb->st_uid = pinfo->pshm_uid;
+               sb->st_gid = pinfo->pshm_gid;
+               sb->st_size = pinfo->pshm_length;
+       }
+       PSHM_SUBSYS_UNLOCK();
 
        return(0);
 }
 
+/*
+ * This is called only from shm_open which holds pshm_lock();
+ * XXX This code is repeated many times
+ */
 int
-pshm_access(struct pshminfo *pinfo, int mode, struct ucred *cred, struct proc *p)
+pshm_access(struct pshminfo *pinfo, int mode, kauth_cred_t cred, __unused proc_t p)
 {
-       mode_t mask;
-       register gid_t *gp;
-       int i, error;
+       int mode_req = ((mode & FREAD) ? S_IRUSR : 0) |
+                      ((mode & FWRITE) ? S_IWUSR : 0);
 
        /* Otherwise, user id 0 always gets access. */
-       if (cred->cr_uid == 0)
+       if (!suser(cred, NULL))
                return (0);
 
-       mask = 0;
-
-       /* Otherwise, check the owner. */
-       if (cred->cr_uid == pinfo->pshm_uid) {
-               if (mode & FREAD)
-                       mask |= S_IRUSR;
-               if (mode & FWRITE)
-                       mask |= S_IWUSR;
-               return ((pinfo->pshm_mode & mask) == mask ? 0 : EACCES);
-       }
-
-       /* Otherwise, check the groups. */
-       for (i = 0, gp = cred->cr_groups; i < cred->cr_ngroups; i++, gp++)
-               if (pinfo->pshm_gid == *gp) {
-                       if (mode & FREAD)
-                               mask |= S_IRGRP;
-                       if (mode & FWRITE)
-                               mask |= S_IWGRP;
-                       return ((pinfo->pshm_mode & mask) == mask ? 0 : EACCES);
-               }
-
-       /* Otherwise, check everyone else. */
-       if (mode & FREAD)
-               mask |= S_IROTH;
-       if (mode & FWRITE)
-               mask |= S_IWOTH;
-       return ((pinfo->pshm_mode & mask) == mask ? 0 : EACCES);
+       return(posix_cred_access(cred, pinfo->pshm_uid, pinfo->pshm_gid, pinfo->pshm_mode, mode_req));
 }
 
-struct mmap_args {
-               caddr_t addr;
-               size_t len;
-               int prot;
-               int flags;
-               int fd;
-#ifdef DOUBLE_ALIGN_PARAMS
-               long pad;
-#endif
-               off_t pos;
-};
-
 int
-pshm_mmap(struct proc *p, struct mmap_args *uap, register_t *retval, struct file *fp, vm_size_t pageoff) 
+pshm_mmap(__unused proc_t p, struct mmap_args *uap, user_addr_t *retval, struct fileproc *fp, off_t pageoff) 
 {
-       vm_offset_t     user_addr = uap->addr;
-       vm_size_t       user_size = uap->len ;
+       vm_map_offset_t user_addr = (vm_map_offset_t)uap->addr;
+       vm_map_size_t   user_size = (vm_map_size_t)uap->len ;
+       vm_map_offset_t user_start_addr;
+       vm_map_size_t   map_size, mapped_size;
        int prot = uap->prot;
        int flags = uap->flags;
        vm_object_offset_t file_pos = (vm_object_offset_t)uap->pos;
-       int fd = uap->fd;
+       vm_object_offset_t map_pos;
        vm_map_t        user_map;
-       boolean_t       find_space,docow;
+       int             alloc_flags;
+       boolean_t       docow;
        kern_return_t   kret;
        struct pshminfo * pinfo;
        struct pshmnode * pnode;
-       void * mem_object;
+       struct pshmobj * pshmobj;
+#if CONFIG_MACF
+       int error;
+#endif
 
        if (user_size == 0) 
                return(0);
@@ -640,57 +870,130 @@ pshm_mmap(struct proc *p, struct mmap_args *uap, register_t *retval, struct file
        if (((pnode = (struct pshmnode *)fp->f_data)) == PSHMNODE_NULL )
                return(EINVAL);
 
-       if ((pinfo = pnode->pinfo) == PSHMINFO_NULL)
+       PSHM_SUBSYS_LOCK();
+       if ((pinfo = pnode->pinfo) == PSHMINFO_NULL) {
+               PSHM_SUBSYS_UNLOCK();
                return(EINVAL);
+       }
 
        if ((pinfo->pshm_flags & PSHM_ALLOCATED) != PSHM_ALLOCATED) {
+               PSHM_SUBSYS_UNLOCK();
                return(EINVAL);
        }
-       if (user_size > pinfo->pshm_length) {
+       if ((off_t)user_size > pinfo->pshm_length) {
+               PSHM_SUBSYS_UNLOCK();
                return(EINVAL);
        }
-       if ((off_t)user_size  + file_pos > pinfo->pshm_length) {
+       if ((off_t)(user_size + file_pos) > pinfo->pshm_length) {
+               PSHM_SUBSYS_UNLOCK();
                return(EINVAL);
        }
-       if ((mem_object =  pinfo->pshm_memobject) == NULL) {
+       if ((pshmobj = pinfo->pshm_memobjects) == NULL) {
+               PSHM_SUBSYS_UNLOCK();
                return(EINVAL);
        }
 
-       
+#if CONFIG_MACF
+       error = mac_posixshm_check_mmap(kauth_cred_get(), pinfo, prot, flags);
+       if (error) {
+               PSHM_SUBSYS_UNLOCK();
+               return(error);
+       }
+#endif
+
+       PSHM_SUBSYS_UNLOCK();
        user_map = current_map();
 
        if ((flags & MAP_FIXED) == 0) {
-               find_space = TRUE;
-               user_addr = round_page(user_addr); 
+               alloc_flags = VM_FLAGS_ANYWHERE;
+               user_addr = vm_map_round_page(user_addr,
+                                             vm_map_page_mask(user_map)); 
        } else {
-               if (user_addr != trunc_page(user_addr))
+               if (user_addr != vm_map_round_page(user_addr,
+                                                  vm_map_page_mask(user_map)))
                        return (EINVAL);
-               find_space = FALSE;
-               (void) vm_deallocate(user_map, user_addr, user_size);
+               /*
+                * We do not get rid of the existing mappings here because
+                * it wouldn't be atomic (see comment in mmap()).  We let
+                * Mach VM know that we want it to replace any existing
+                * mapping with the new one.
+                */
+               alloc_flags = VM_FLAGS_FIXED | VM_FLAGS_OVERWRITE;
        }
        docow = FALSE;  
 
-       kret = vm_map_64(user_map, &user_addr, user_size,
-                       0, find_space, pinfo->pshm_memobject, file_pos, docow,
-                       prot, VM_PROT_DEFAULT, 
-                       VM_INHERIT_DEFAULT);
-
-       if (kret != KERN_SUCCESS) 
-                       goto out;
-       kret = vm_inherit(user_map, user_addr, user_size,
-                               VM_INHERIT_SHARE);
+       mapped_size = 0;
+
+       /* reserver the entire space first... */
+       kret = vm_map_enter_mem_object(user_map,
+                                      &user_addr,
+                                      user_size,
+                                      0,
+                                      alloc_flags,
+                                      IPC_PORT_NULL,
+                                      0,
+                                      FALSE,
+                                      VM_PROT_NONE,
+                                      VM_PROT_NONE,
+                                      VM_INHERIT_NONE);
+       user_start_addr = user_addr;
        if (kret != KERN_SUCCESS) {
-               (void) vm_deallocate(user_map, user_addr, user_size);
                goto out;
        }
-       pnode->mapp_addr = user_addr;
-       pnode->map_size = user_size;
+
+       /* ... and overwrite with the real mappings */
+       for (map_pos = 0, pshmobj = pinfo->pshm_memobjects;
+            user_size != 0;
+            map_pos += pshmobj->pshmo_size, pshmobj = pshmobj->pshmo_next) {
+               if (pshmobj == NULL) {
+                       /* nothing there to map !? */
+                       goto out;
+               }
+               if (file_pos >= map_pos + pshmobj->pshmo_size) {
+                       continue;
+               }
+               map_size = pshmobj->pshmo_size - (file_pos - map_pos);
+               if (map_size > user_size) {
+                       map_size = user_size;
+               }
+               kret = vm_map_enter_mem_object(
+                       user_map,
+                       &user_addr,
+                       map_size,
+                       0,
+                       VM_FLAGS_FIXED | VM_FLAGS_OVERWRITE,
+                       pshmobj->pshmo_memobject,
+                       file_pos - map_pos,
+                       docow,
+                       prot,
+                       VM_PROT_DEFAULT, 
+                       VM_INHERIT_SHARE);
+               if (kret != KERN_SUCCESS) 
+                       goto out;
+
+               user_addr += map_size;
+               user_size -= map_size;
+               mapped_size += map_size;
+               file_pos += map_size;
+       }
+
+       PSHM_SUBSYS_LOCK();
+       pnode->mapp_addr = user_start_addr;
+       pnode->map_size = mapped_size;
        pinfo->pshm_flags |= (PSHM_MAPPED | PSHM_INUSE);
+       PSHM_SUBSYS_UNLOCK();
 out:
+       if (kret != KERN_SUCCESS) {
+               if (mapped_size != 0) {
+                       (void) mach_vm_deallocate(current_map(),
+                                                 user_start_addr,
+                                                 mapped_size);
+               }
+       }
+
        switch (kret) {
        case KERN_SUCCESS:
-               *fdflags(p, fd) |= UF_MAPPED;
-               *retval = (register_t)(user_addr + pageoff);
+               *retval = (user_start_addr + pageoff);
                return (0);
        case KERN_INVALID_ADDRESS:
        case KERN_NO_SPACE:
@@ -703,43 +1006,34 @@ out:
 
 }
 
-struct shm_unlink_args {
-       const char *name;
-};
-
 int
-shm_unlink(p, uap, retval)
-       struct proc *p;
-       register struct shm_unlink_args *uap;
-       register_t *retval;
+shm_unlink(__unused proc_t p, struct shm_unlink_args *uap, 
+                       __unused int32_t *retval)
 {
-       register struct filedesc *fdp = p->p_fd;
-       register struct file *fp;
-       int flags, i;
+       size_t i;
        int error=0;
        struct pshmname nd;
        struct pshminfo *pinfo;
-       extern struct fileops pshmops;
        char * pnbuf;
        char * nameptr;
        char * cp;
        size_t pathlen, plen;
-       int fmode, cmode ;
        int incache = 0;
-       struct pshmnode * pnode = PSHMNODE_NULL;
        struct pshmcache *pcache = PSHMCACHE_NULL;
-       kern_return_t kret;
+       struct pshmobj *pshmobj, *pshmobj_next;
 
        pinfo = PSHMINFO_NULL;
 
-       MALLOC_ZONE(pnbuf, caddr_t,
-                       MAXPATHLEN, M_NAMEI, M_WAITOK);
+       MALLOC_ZONE(pnbuf, caddr_t, MAXPATHLEN, M_NAMEI, M_WAITOK);
+       if (pnbuf == NULL) {
+               return(ENOSPC);         /* XXX non-standard */
+       }
        pathlen = MAXPATHLEN;
-       error = copyinstr(uap->name, pnbuf,
-               MAXPATHLEN, &pathlen);
+       error = copyinstr(uap->name, (void *)pnbuf, MAXPATHLEN, &pathlen);
        if (error) {
                goto bad;
        }
+       AUDIT_ARG(text, pnbuf);
        if (pathlen > PSHMNAMLEN) {
                error = ENAMETOOLONG;
                goto bad;
@@ -770,68 +1064,106 @@ shm_unlink(p, uap, retval)
                nd.pshm_hash += (unsigned char)*cp * i;
        }
 
-       error = pshm_cache_search(&pinfo, &nd, &pcache);
+       PSHM_SUBSYS_LOCK();
+       error = pshm_cache_search(&pinfo, &nd, &pcache, 0);
 
        if (error == ENOENT) {
-               error = EINVAL;
+               PSHM_SUBSYS_UNLOCK();
                goto bad;
 
        }
+       /* During unlink lookup failure also implies ENOENT */ 
        if (!error) {
-               error = EINVAL;
+               PSHM_SUBSYS_UNLOCK();
+               error = ENOENT;
                goto bad;
        } else
                incache = 1;
 
        if ((pinfo->pshm_flags & (PSHM_DEFINED | PSHM_ALLOCATED))==0) {
-               return (EINVAL);
+               PSHM_SUBSYS_UNLOCK();
+               error = EINVAL;
+               goto bad;
+       }
+
+       if (pinfo->pshm_flags & PSHM_ALLOCATING) {
+               /* XXX should we wait for flag to clear and then proceed ? */
+               PSHM_SUBSYS_UNLOCK();
+               error = EAGAIN;
+               goto bad;
        }
 
        if (pinfo->pshm_flags & PSHM_INDELETE) {
+               PSHM_SUBSYS_UNLOCK();
                error = 0;
                goto bad;
        }
+#if CONFIG_MACF
+       error = mac_posixshm_check_unlink(kauth_cred_get(), pinfo, nameptr);
+       if (error) {
+               PSHM_SUBSYS_UNLOCK();
+               goto bad;
+       }
+#endif
 
-       if (pinfo->pshm_memobject == NULL) {
-               error = EINVAL;
+       AUDIT_ARG(posix_ipc_perm, pinfo->pshm_uid, pinfo->pshm_gid,
+                 pinfo->pshm_mode);
+
+       /* 
+        * following file semantics, unlink should be allowed 
+        * for users with write permission only. 
+        */
+       if ( (error = pshm_access(pinfo, FWRITE, kauth_cred_get(), p)) ) {
+               PSHM_SUBSYS_UNLOCK();
                goto bad;
        }
 
        pinfo->pshm_flags |= PSHM_INDELETE;
-       pinfo->pshm_usecount--;
-       kret = mach_destroy_memory_entry(pinfo->pshm_memobject);
        pshm_cache_delete(pcache);
-       _FREE(pcache, M_SHM);
        pinfo->pshm_flags |= PSHM_REMOVED;
+       /* release the existence reference */
+       if (!--pinfo->pshm_usecount) {
+#if CONFIG_MACF
+               mac_posixshm_label_destroy(pinfo);
+#endif
+               PSHM_SUBSYS_UNLOCK();
+               /*
+                * If this is the last reference going away on the object,
+                * then we need to destroy the backing object.  The name
+                * has an implied but uncounted reference on the object,
+                * once it's created, since it's used as a rendezvous, and
+                * therefore may be subsequently reopened.
+                */
+               for (pshmobj = pinfo->pshm_memobjects;
+                    pshmobj != NULL;
+                    pshmobj = pshmobj_next) {
+                       mach_memory_entry_port_release(pshmobj->pshmo_memobject);
+                       pshmobj_next = pshmobj->pshmo_next;
+                       FREE(pshmobj, M_SHM);
+               }
+               FREE(pinfo,M_SHM);
+       } else {
+               PSHM_SUBSYS_UNLOCK();
+       }
+       FREE(pcache, M_SHM);
        error = 0;
 bad:
-       _FREE_ZONE(pnbuf, MAXPATHLEN, M_NAMEI);
+       FREE_ZONE(pnbuf, MAXPATHLEN, M_NAMEI);
        return (error);
-out:
-       switch (kret) {
-       case KERN_INVALID_ADDRESS:
-       case KERN_PROTECTION_FAILURE:
-               return (EACCES);
-       default:
-               return (EINVAL);
-       }
 }
 
-int
-pshm_close(pnode, flags, cred, p)
-       register struct pshmnode *pnode;
-       int flags;
-       struct ucred *cred;
-       struct proc *p;
+/* already called locked */
+static int
+pshm_close(struct pshminfo *pinfo, int dropref)
 {
-       int error=0;
-       kern_return_t kret;
-       register struct pshminfo *pinfo;
-
-       if ((pinfo = pnode->pinfo) == PSHMINFO_NULL)
-               return(EINVAL);
+       int error = 0;
+       struct pshmobj *pshmobj, *pshmobj_next;
 
-       if ((pinfo->pshm_flags & PSHM_ALLOCATED) != PSHM_ALLOCATED) {
+       /*
+        * If we are dropping the reference we took on the cache object, don't
+        * enforce the allocation requirement.
+        */
+       if ( !dropref && ((pinfo->pshm_flags & PSHM_ALLOCATED) != PSHM_ALLOCATED)) {
                return(EINVAL);
        }
 #if DIAGNOSTIC
@@ -839,62 +1171,129 @@ pshm_close(pnode, flags, cred, p)
                kprintf("negative usecount in pshm_close\n");
        }
 #endif /* DIAGNOSTIC */
-       pinfo->pshm_usecount--;
+       pinfo->pshm_usecount--; /* release this fd's reference */
 
        if ((pinfo->pshm_flags & PSHM_REMOVED) && !pinfo->pshm_usecount) {
-               _FREE(pinfo,M_SHM);
+#if CONFIG_MACF
+               mac_posixshm_label_destroy(pinfo);
+#endif
+               PSHM_SUBSYS_UNLOCK();
+               /*
+                * If this is the last reference going away on the object,
+                * then we need to destroy the backing object.
+                */
+               for (pshmobj = pinfo->pshm_memobjects;
+                    pshmobj != NULL;
+                    pshmobj = pshmobj_next) {
+                       mach_memory_entry_port_release(pshmobj->pshmo_memobject);
+                       pshmobj_next = pshmobj->pshmo_next;
+                       FREE(pshmobj, M_SHM);
+               }
+               PSHM_SUBSYS_LOCK();
+               FREE(pinfo,M_SHM);
        }
-       _FREE(pnode, M_SHM);
        return (error);
 }
 
+/* vfs_context_t passed to match prototype for struct fileops */
+static int
+pshm_closefile(struct fileglob *fg, __unused vfs_context_t ctx)
+{
+       int error = EINVAL;
+       struct pshmnode *pnode;
+
+       PSHM_SUBSYS_LOCK();
+
+       if ((pnode = (struct pshmnode *)fg->fg_data) != NULL) {
+               if (pnode->pinfo != PSHMINFO_NULL) {
+                       error =  pshm_close(pnode->pinfo, 0);
+               }
+               FREE(pnode, M_SHM);
+       }
+
+       PSHM_SUBSYS_UNLOCK();
+
+       return(error);
+}
+
 static int
-pshm_closefile(fp, p)
-       struct file *fp;
-       struct proc *p;
+pshm_read(__unused struct fileproc *fp, __unused struct uio *uio, 
+                       __unused int flags, __unused vfs_context_t ctx)
 {
-       return (pshm_close(((struct pshmnode *)fp->f_data), fp->f_flag,
-               fp->f_cred, p));
+       return(ENOTSUP);
 }
 
 static int
-pshm_read(fp, uio, cred, flags, p)
-       struct file *fp;
-       struct uio *uio;
-       struct ucred *cred;
-       int flags;
-       struct proc *p;
+pshm_write(__unused struct fileproc *fp, __unused struct uio *uio, 
+                       __unused int flags, __unused vfs_context_t ctx)
 {
-       return(EOPNOTSUPP);
+       return(ENOTSUP);
 }
 
 static int
-pshm_write(fp, uio, cred, flags, p)
-       struct file *fp;
-       struct uio *uio;
-       struct ucred *cred;
-       int flags;
-       struct proc *p;
+pshm_ioctl(__unused struct fileproc *fp, __unused u_long com, 
+                       __unused caddr_t data, __unused vfs_context_t ctx)
 {
-       return(EOPNOTSUPP);
+       return(ENOTSUP);
 }
 
 static int
-pshm_ioctl(fp, com, data, p)
-       struct file *fp;
-       u_long com;
-       caddr_t data;
-       struct proc *p;
+pshm_select(__unused struct fileproc *fp, __unused int which, __unused void *wql, 
+                       __unused vfs_context_t ctx)
 {
-       return(EOPNOTSUPP);
+       return(ENOTSUP);
 }
 
 static int
-pshm_select(fp, which, wql, p)
-       struct file *fp;
-       int which;
-       void *wql;
-       struct proc *p;
+pshm_kqfilter(__unused struct fileproc *fp, __unused struct knote *kn, 
+                               __unused vfs_context_t ctx)
 {
-       return(EOPNOTSUPP);
+       return(ENOTSUP);
 }
+
+int
+fill_pshminfo(struct pshmnode * pshm, struct pshm_info * info)
+{
+       struct pshminfo *pinfo;
+       struct vinfo_stat *sb;
+       
+       PSHM_SUBSYS_LOCK();
+       if ((pinfo = pshm->pinfo) == PSHMINFO_NULL){
+               PSHM_SUBSYS_UNLOCK();
+               return(EINVAL);
+       }
+
+       sb = &info->pshm_stat;
+
+       bzero(sb, sizeof(struct vinfo_stat)); 
+       sb->vst_mode = pinfo->pshm_mode;
+       sb->vst_uid = pinfo->pshm_uid;
+       sb->vst_gid = pinfo->pshm_gid;
+       sb->vst_size = pinfo->pshm_length;
+
+       info->pshm_mappaddr = pshm->mapp_addr;
+       bcopy(&pinfo->pshm_name[0], &info->pshm_name[0], PSHMNAMLEN+1); 
+
+       PSHM_SUBSYS_UNLOCK();
+       return(0);
+}
+
+#if CONFIG_MACF
+void
+pshm_label_associate(struct fileproc *fp, struct vnode *vp, vfs_context_t ctx)
+{
+       struct pshmnode *pnode;
+       struct pshminfo *pshm;
+
+       PSHM_SUBSYS_LOCK();
+       pnode = (struct pshmnode *)fp->f_fglob->fg_data;
+       if (pnode != NULL) {
+               pshm = pnode->pinfo;
+               if (pshm != NULL)
+                       mac_posixshm_vnode_label_associate(
+                               vfs_context_ucred(ctx), pshm, pshm->pshm_label,
+                               vp, vp->v_label);
+       }
+       PSHM_SUBSYS_UNLOCK();
+}
+#endif