/*-
 * SPDX-License-Identifier: BSD-4-Clause AND BSD-2-Clause
 *
 * Copyright (c) 1994 Adam Glass and Charles Hannum.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by Adam Glass and Charles
 *      Hannum.
 * 4. The names of the authors may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * $NetBSD: sysv_shm.c,v 1.39 1997/10/07 10:02:03 drochner Exp $
 */
/*-
 * Copyright (c) 2003-2005 McAfee, Inc.
 * Copyright (c) 2016-2017 Robert N. M. Watson
 * All rights reserved.
 *
 * This software was developed for the FreeBSD Project in part by McAfee
 * Research, the Security Research Division of McAfee, Inc under DARPA/SPAWAR
 * contract N66001-01-C-8035 ("CBOSS"), as part of the DARPA CHATS research
 * program.
 *
 * Portions of this software were developed by BAE Systems, the University of
 * Cambridge Computer Laboratory, and Memorial University under DARPA/AFRL
 * contract FA8650-15-C-7558 ("CADETS"), as part of the DARPA Transparent
 * Computing (TC) research program.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include "opt_sysvipc.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/abi_compat.h>
#include <sys/kernel.h>
#include <sys/limits.h>
#include <sys/lock.h>
#include <sys/sysctl.h>
#include <sys/shm.h>
#include <sys/proc.h>
#include <sys/malloc.h>
#include <sys/mman.h>
#include <sys/module.h>
#include <sys/mutex.h>
#include <sys/racct.h>
#include <sys/resourcevar.h>
#include <sys/rwlock.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <sys/syscallsubr.h>
#include <sys/sysent.h>
#include <sys/sysproto.h>
#include <sys/jail.h>

#include <security/audit/audit.h>
#include <security/mac/mac_framework.h>

#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/pmap.h>
#include <vm/vm_object.h>
#include <vm/vm_map.h>
#include <vm/vm_page.h>
#include <vm/vm_pager.h>

FEATURE(sysv_shm, "System V shared memory segments support");

static MALLOC_DEFINE(M_SHM, "shm", "SVID compatible shared memory segments");

static int shm_last_free, shm_nused, shmalloced;
vm_size_t shm_committed;
static struct shmid_kernel *shmsegs;
static unsigned shm_prison_slot;

struct shmmap_state {
        vm_offset_t va;
        int shmid;
};

static void shm_deallocate_segment(struct shmid_kernel *);
static int shm_find_segment_by_key(struct prison *, key_t);
static struct shmid_kernel *shm_find_segment(struct prison *, int, bool);
static int shm_delete_mapping(struct vmspace *vm, struct shmmap_state *);
static int shmget_allocate_segment(struct thread *td, key_t key, size_t size,
    int mode);
static int shmget_existing(struct thread *td, size_t size, int shmflg,
    int mode, int segnum);
static void shmrealloc(void);
static int shminit(void);
static int sysvshm_modload(struct module *, int, void *);
static int shmunload(void);
#ifndef SYSVSHM
static void shmexit_myhook(struct vmspace *vm);
static void shmfork_myhook(struct proc *p1, struct proc *p2);
static void shmobjinfo_myhook(vm_object_t obj, key_t *key,
    unsigned short *seq);
#endif
static int sysctl_shmsegs(SYSCTL_HANDLER_ARGS);
static void shm_remove(struct shmid_kernel *, int);
static struct prison *shm_find_prison(struct ucred *);
static int shm_prison_cansee(struct prison *, struct shmid_kernel *);
static int shm_prison_check(void *, void *);
static int shm_prison_set(void *, void *);
static int shm_prison_get(void *, void *);
static int shm_prison_remove(void *, void *);
static void shm_prison_cleanup(struct prison *);

/*
 * Tuneable values.
 */
#ifndef SHMMAXPGS
#define SHMMAXPGS       131072ul /* Note: sysv shared memory is swap backed. */
#endif
#ifndef SHMMAX
#define SHMMAX  (SHMMAXPGS*PAGE_SIZE)
#endif
#ifndef SHMMIN
#define SHMMIN  1
#endif
#ifndef SHMMNI
#define SHMMNI  192
#endif
#ifndef SHMSEG
#define SHMSEG  128
#endif
#ifndef SHMALL
#define SHMALL  (SHMMAXPGS)
#endif

struct  shminfo shminfo = {
        .shmmax = SHMMAX,
        .shmmin = SHMMIN,
        .shmmni = SHMMNI,
        .shmseg = SHMSEG,
        .shmall = SHMALL
};

static int shm_use_phys;
static int shm_allow_removed = 1;

SYSCTL_ULONG(_kern_ipc, OID_AUTO, shmmax, CTLFLAG_RWTUN, &shminfo.shmmax, 0,
    "Maximum shared memory segment size");
SYSCTL_ULONG(_kern_ipc, OID_AUTO, shmmin, CTLFLAG_RWTUN, &shminfo.shmmin, 0,
    "Minimum shared memory segment size");
SYSCTL_ULONG(_kern_ipc, OID_AUTO, shmmni, CTLFLAG_RDTUN, &shminfo.shmmni, 0,
    "Number of shared memory identifiers");
SYSCTL_ULONG(_kern_ipc, OID_AUTO, shmseg, CTLFLAG_RDTUN, &shminfo.shmseg, 0,
    "Number of segments per process");
SYSCTL_ULONG(_kern_ipc, OID_AUTO, shmall, CTLFLAG_RWTUN, &shminfo.shmall, 0,
    "Maximum number of pages available for shared memory");
SYSCTL_INT(_kern_ipc, OID_AUTO, shm_use_phys, CTLFLAG_RWTUN,
    &shm_use_phys, 0, "Enable/Disable locking of shared memory pages in core");
SYSCTL_INT(_kern_ipc, OID_AUTO, shm_allow_removed, CTLFLAG_RWTUN,
    &shm_allow_removed, 0,
    "Enable/Disable attachment to attached segments marked for removal");
SYSCTL_PROC(_kern_ipc, OID_AUTO, shmsegs, CTLTYPE_OPAQUE | CTLFLAG_RD |
    CTLFLAG_MPSAFE, NULL, 0, sysctl_shmsegs, "",
    "Array of struct shmid_kernel for each potential shared memory segment");

static struct sx sysvshmsx;
#define SYSVSHM_LOCK()          sx_xlock(&sysvshmsx)
#define SYSVSHM_UNLOCK()        sx_xunlock(&sysvshmsx)
#define SYSVSHM_ASSERT_LOCKED() sx_assert(&sysvshmsx, SA_XLOCKED)

static int
shm_find_segment_by_key(struct prison *pr, key_t key)
{
        int i;

        for (i = 0; i < shmalloced; i++)
                if ((shmsegs[i].u.shm_perm.mode & SHMSEG_ALLOCATED) &&
                    shmsegs[i].cred != NULL &&
                    shmsegs[i].cred->cr_prison == pr &&
                    shmsegs[i].u.shm_perm.key == key)
                        return (i);
        return (-1);
}

/*
 * Finds segment either by shmid if is_shmid is true, or by segnum if
 * is_shmid is false.
 */
static struct shmid_kernel *
shm_find_segment(struct prison *rpr, int arg, bool is_shmid)
{
        struct shmid_kernel *shmseg;
        int segnum;

        segnum = is_shmid ? IPCID_TO_IX(arg) : arg;
        if (segnum < 0 || segnum >= shmalloced)
                return (NULL);
        shmseg = &shmsegs[segnum];
        if ((shmseg->u.shm_perm.mode & SHMSEG_ALLOCATED) == 0 ||
            (!shm_allow_removed &&
            (shmseg->u.shm_perm.mode & SHMSEG_REMOVED) != 0) ||
            (is_shmid && shmseg->u.shm_perm.seq != IPCID_TO_SEQ(arg)) ||
            shm_prison_cansee(rpr, shmseg) != 0)
                return (NULL);
        return (shmseg);
}

static void
shm_deallocate_segment(struct shmid_kernel *shmseg)
{
        vm_size_t size;

        SYSVSHM_ASSERT_LOCKED();

        vm_object_deallocate(shmseg->object);
        shmseg->object = NULL;
        size = round_page(shmseg->u.shm_segsz);
        shm_committed -= btoc(size);
        shm_nused--;
        shmseg->u.shm_perm.mode = SHMSEG_FREE;
#ifdef MAC
        mac_sysvshm_cleanup(shmseg);
#endif
        racct_sub_cred(shmseg->cred, RACCT_NSHM, 1);
        racct_sub_cred(shmseg->cred, RACCT_SHMSIZE, size);
        crfree(shmseg->cred);
        shmseg->cred = NULL;
}

static int
shm_delete_mapping(struct vmspace *vm, struct shmmap_state *shmmap_s)
{
        struct shmid_kernel *shmseg;
        int segnum, result;
        vm_size_t size;

        SYSVSHM_ASSERT_LOCKED();
        segnum = IPCID_TO_IX(shmmap_s->shmid);
        KASSERT(segnum >= 0 && segnum < shmalloced,
            ("segnum %d shmalloced %d", segnum, shmalloced));

        shmseg = &shmsegs[segnum];
        size = round_page(shmseg->u.shm_segsz);
        result = vm_map_remove(&vm->vm_map, shmmap_s->va, shmmap_s->va + size);
        if (result != KERN_SUCCESS)
                return (EINVAL);
        shmmap_s->shmid = -1;
        shmseg->u.shm_dtime = time_second;
        if (--shmseg->u.shm_nattch == 0 &&
            (shmseg->u.shm_perm.mode & SHMSEG_REMOVED)) {
                shm_deallocate_segment(shmseg);
                shm_last_free = segnum;
        }
        return (0);
}

static void
shm_remove(struct shmid_kernel *shmseg, int segnum)
{

        shmseg->u.shm_perm.key = IPC_PRIVATE;
        shmseg->u.shm_perm.mode |= SHMSEG_REMOVED;
        if (shmseg->u.shm_nattch == 0) {
                shm_deallocate_segment(shmseg);
                shm_last_free = segnum;
        }
}

static struct prison *
shm_find_prison(struct ucred *cred)
{
        struct prison *pr, *rpr;

        pr = cred->cr_prison;
        prison_lock(pr);
        rpr = osd_jail_get(pr, shm_prison_slot);
        prison_unlock(pr);
        return rpr;
}

static int
shm_prison_cansee(struct prison *rpr, struct shmid_kernel *shmseg)
{

        if (shmseg->cred == NULL ||
            !(rpr == shmseg->cred->cr_prison ||
              prison_ischild(rpr, shmseg->cred->cr_prison)))
                return (EINVAL);
        return (0);
}

static int
kern_shmdt_locked(struct thread *td, const void *shmaddr)
{
        struct proc *p = td->td_proc;
        struct shmmap_state *shmmap_s;
#ifdef MAC
        int error;
#endif
        int i;

        SYSVSHM_ASSERT_LOCKED();
        if (shm_find_prison(td->td_ucred) == NULL)
                return (ENOSYS);
        shmmap_s = p->p_vmspace->vm_shm;
        if (shmmap_s == NULL)
                return (EINVAL);
        AUDIT_ARG_SVIPC_ID(shmmap_s->shmid);
        for (i = 0; i < shminfo.shmseg; i++, shmmap_s++) {
                if (shmmap_s->shmid != -1 &&
                    shmmap_s->va == (vm_offset_t)shmaddr) {
                        break;
                }
        }
        if (i == shminfo.shmseg)
                return (EINVAL);
#ifdef MAC
        error = mac_sysvshm_check_shmdt(td->td_ucred,
            &shmsegs[IPCID_TO_IX(shmmap_s->shmid)]);
        if (error != 0)
                return (error);
#endif
        return (shm_delete_mapping(p->p_vmspace, shmmap_s));
}

#ifndef _SYS_SYSPROTO_H_
struct shmdt_args {
        const void *shmaddr;
};
#endif
int
sys_shmdt(struct thread *td, struct shmdt_args *uap)
{
        int error;

        SYSVSHM_LOCK();
        error = kern_shmdt_locked(td, uap->shmaddr);
        SYSVSHM_UNLOCK();
        return (error);
}

static int
kern_shmat_locked(struct thread *td, int shmid, const void *shmaddr,
    int shmflg)
{
        struct prison *rpr;
        struct proc *p = td->td_proc;
        struct shmid_kernel *shmseg;
        struct shmmap_state *shmmap_s;
        vm_offset_t attach_va;
        vm_prot_t prot;
        vm_size_t size;
        int cow, error, find_space, i, rv;

        AUDIT_ARG_SVIPC_ID(shmid);
        AUDIT_ARG_VALUE(shmflg);

        SYSVSHM_ASSERT_LOCKED();
        rpr = shm_find_prison(td->td_ucred);
        if (rpr == NULL)
                return (ENOSYS);
        shmmap_s = p->p_vmspace->vm_shm;
        if (shmmap_s == NULL) {
                shmmap_s = malloc(shminfo.shmseg * sizeof(struct shmmap_state),
                    M_SHM, M_WAITOK);
                for (i = 0; i < shminfo.shmseg; i++)
                        shmmap_s[i].shmid = -1;
                KASSERT(p->p_vmspace->vm_shm == NULL, ("raced"));
                p->p_vmspace->vm_shm = shmmap_s;
        }
        shmseg = shm_find_segment(rpr, shmid, true);
        if (shmseg == NULL)
                return (EINVAL);
        error = ipcperm(td, &shmseg->u.shm_perm,
            (shmflg & SHM_RDONLY) ? IPC_R : IPC_R|IPC_W);
        if (error != 0)
                return (error);
#ifdef MAC
        error = mac_sysvshm_check_shmat(td->td_ucred, shmseg, shmflg);
        if (error != 0)
                return (error);
#endif
        for (i = 0; i < shminfo.shmseg; i++) {
                if (shmmap_s->shmid == -1)
                        break;
                shmmap_s++;
        }
        if (i >= shminfo.shmseg)
                return (EMFILE);
        size = round_page(shmseg->u.shm_segsz);
        prot = VM_PROT_READ;
        cow = MAP_INHERIT_SHARE | MAP_PREFAULT_PARTIAL;
        if ((shmflg & SHM_RDONLY) == 0)
                prot |= VM_PROT_WRITE;
        if (shmaddr != NULL) {
                if ((shmflg & SHM_RND) != 0)
                        attach_va = rounddown2((vm_offset_t)shmaddr, SHMLBA);
                else if (((vm_offset_t)shmaddr & (SHMLBA-1)) == 0)
                        attach_va = (vm_offset_t)shmaddr;
                else
                        return (EINVAL);
                if ((shmflg & SHM_REMAP) != 0)
                        cow |= MAP_REMAP;
                find_space = VMFS_NO_SPACE;
        } else {
                /*
                 * This is just a hint to vm_map_find() about where to
                 * put it.
                 */
                attach_va = round_page((vm_offset_t)p->p_vmspace->vm_daddr +
                    lim_max(td, RLIMIT_DATA));
                find_space = VMFS_OPTIMAL_SPACE;
        }

        vm_object_reference(shmseg->object);
        rv = vm_map_find(&p->p_vmspace->vm_map, shmseg->object, 0, &attach_va,
            size, 0, find_space, prot, prot, cow);
        if (rv != KERN_SUCCESS) {
                vm_object_deallocate(shmseg->object);
                return (ENOMEM);
        }

        shmmap_s->va = attach_va;
        shmmap_s->shmid = shmid;
        shmseg->u.shm_lpid = p->p_pid;
        shmseg->u.shm_atime = time_second;
        shmseg->u.shm_nattch++;
        td->td_retval[0] = attach_va;
        return (error);
}

int
kern_shmat(struct thread *td, int shmid, const void *shmaddr, int shmflg)
{
        int error;

        SYSVSHM_LOCK();
        error = kern_shmat_locked(td, shmid, shmaddr, shmflg);
        SYSVSHM_UNLOCK();
        return (error);
}

#ifndef _SYS_SYSPROTO_H_
struct shmat_args {
        int shmid;
        const void *shmaddr;
        int shmflg;
};
#endif
int
sys_shmat(struct thread *td, struct shmat_args *uap)
{

        return (kern_shmat(td, uap->shmid, uap->shmaddr, uap->shmflg));
}

static int
kern_shmctl_locked(struct thread *td, int shmid, int cmd, void *buf,
    size_t *bufsz)
{
        struct prison *rpr;
        struct shmid_kernel *shmseg;
        struct shmid_ds *shmidp;
        struct shm_info shm_info;
        int error;

        SYSVSHM_ASSERT_LOCKED();

        rpr = shm_find_prison(td->td_ucred);
        if (rpr == NULL)
                return (ENOSYS);

        AUDIT_ARG_SVIPC_ID(shmid);
        AUDIT_ARG_SVIPC_CMD(cmd);

        switch (cmd) {
        /*
         * It is possible that kern_shmctl is being called from the Linux ABI
         * layer, in which case, we will need to implement IPC_INFO.  It should
         * be noted that other shmctl calls will be funneled through here for
         * Linix binaries as well.
         *
         * NB: The Linux ABI layer will convert this data to structure(s) more
         * consistent with the Linux ABI.
         */
        case IPC_INFO:
                memcpy(buf, &shminfo, sizeof(shminfo));
                if (bufsz)
                        *bufsz = sizeof(shminfo);
                td->td_retval[0] = shmalloced;
                return (0);
        case SHM_INFO: {
                shm_info.used_ids = shm_nused;
                shm_info.shm_rss = 0;   /*XXX where to get from ? */
                shm_info.shm_tot = 0;   /*XXX where to get from ? */
                shm_info.shm_swp = 0;   /*XXX where to get from ? */
                shm_info.swap_attempts = 0;     /*XXX where to get from ? */
                shm_info.swap_successes = 0;    /*XXX where to get from ? */
                memcpy(buf, &shm_info, sizeof(shm_info));
                if (bufsz != NULL)
                        *bufsz = sizeof(shm_info);
                td->td_retval[0] = shmalloced;
                return (0);
        }
        }
        shmseg = shm_find_segment(rpr, shmid, cmd != SHM_STAT);
        if (shmseg == NULL)
                return (EINVAL);
#ifdef MAC
        error = mac_sysvshm_check_shmctl(td->td_ucred, shmseg, cmd);
        if (error != 0)
                return (error);
#endif
        switch (cmd) {
        case SHM_STAT:
        case IPC_STAT:
                shmidp = (struct shmid_ds *)buf;
                error = ipcperm(td, &shmseg->u.shm_perm, IPC_R);
                if (error != 0)
                        return (error);
                memcpy(shmidp, &shmseg->u, sizeof(struct shmid_ds));
                if (td->td_ucred->cr_prison != shmseg->cred->cr_prison)
                        shmidp->shm_perm.key = IPC_PRIVATE;
                if (bufsz != NULL)
                        *bufsz = sizeof(struct shmid_ds);
                if (cmd == SHM_STAT) {
                        td->td_retval[0] = IXSEQ_TO_IPCID(shmid,
                            shmseg->u.shm_perm);
                }
                break;
        case IPC_SET:
                shmidp = (struct shmid_ds *)buf;
                AUDIT_ARG_SVIPC_PERM(&shmidp->shm_perm);
                error = ipcperm(td, &shmseg->u.shm_perm, IPC_M);
                if (error != 0)
                        return (error);
                shmseg->u.shm_perm.uid = shmidp->shm_perm.uid;
                shmseg->u.shm_perm.gid = shmidp->shm_perm.gid;
                shmseg->u.shm_perm.mode =
                    (shmseg->u.shm_perm.mode & ~ACCESSPERMS) |
                    (shmidp->shm_perm.mode & ACCESSPERMS);
                shmseg->u.shm_ctime = time_second;
                break;
        case IPC_RMID:
                error = ipcperm(td, &shmseg->u.shm_perm, IPC_M);
                if (error != 0)
                        return (error);
                shm_remove(shmseg, IPCID_TO_IX(shmid));
                break;
#if 0
        case SHM_LOCK:
        case SHM_UNLOCK:
#endif
        default:
                error = EINVAL;
                break;
        }
        return (error);
}

int
kern_shmctl(struct thread *td, int shmid, int cmd, void *buf, size_t *bufsz)
{
        int error;

        SYSVSHM_LOCK();
        error = kern_shmctl_locked(td, shmid, cmd, buf, bufsz);
        SYSVSHM_UNLOCK();
        return (error);
}

#ifndef _SYS_SYSPROTO_H_
struct shmctl_args {
        int shmid;
        int cmd;
        struct shmid_ds *buf;
};
#endif
int
sys_shmctl(struct thread *td, struct shmctl_args *uap)
{
        int error;
        struct shmid_ds buf;
        size_t bufsz;

        /*
         * The only reason IPC_INFO, SHM_INFO, SHM_STAT exists is to support
         * Linux binaries.  If we see the call come through the FreeBSD ABI,
         * return an error back to the user since we do not to support this.
         */
        if (uap->cmd == IPC_INFO || uap->cmd == SHM_INFO ||
            uap->cmd == SHM_STAT)
                return (EINVAL);

        /* IPC_SET needs to copyin the buffer before calling kern_shmctl */
        if (uap->cmd == IPC_SET) {
                if ((error = copyin(uap->buf, &buf, sizeof(struct shmid_ds))))
                        goto done;
        }

        error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&buf, &bufsz);
        if (error)
                goto done;

        /* Cases in which we need to copyout */
        switch (uap->cmd) {
        case IPC_STAT:
                error = copyout(&buf, uap->buf, bufsz);
                break;
        }

done:
        if (error) {
                /* Invalidate the return value */
                td->td_retval[0] = -1;
        }
        return (error);
}

static int
shmget_existing(struct thread *td, size_t size, int shmflg, int mode,
    int segnum)
{
        struct shmid_kernel *shmseg;
#ifdef MAC
        int error;
#endif

        SYSVSHM_ASSERT_LOCKED();
        KASSERT(segnum >= 0 && segnum < shmalloced,
            ("segnum %d shmalloced %d", segnum, shmalloced));
        shmseg = &shmsegs[segnum];
        if ((shmflg & (IPC_CREAT | IPC_EXCL)) == (IPC_CREAT | IPC_EXCL))
                return (EEXIST);
#ifdef MAC
        error = mac_sysvshm_check_shmget(td->td_ucred, shmseg, shmflg);
        if (error != 0)
                return (error);
#endif
        if (size != 0 && size > shmseg->u.shm_segsz)
                return (EINVAL);
        td->td_retval[0] = IXSEQ_TO_IPCID(segnum, shmseg->u.shm_perm);
        return (0);
}

static int
shmget_allocate_segment(struct thread *td, key_t key, size_t size, int mode)
{
        struct ucred *cred = td->td_ucred;
        struct shmid_kernel *shmseg;
        vm_object_t shm_object;
        int i, segnum;

        SYSVSHM_ASSERT_LOCKED();

        if (size < shminfo.shmmin || size > shminfo.shmmax)
                return (EINVAL);
        if (shm_nused >= shminfo.shmmni) /* Any shmids left? */
                return (ENOSPC);
        size = round_page(size);
        if (shm_committed + btoc(size) > shminfo.shmall)
                return (ENOMEM);
        if (shm_last_free < 0) {
                shmrealloc();   /* Maybe expand the shmsegs[] array. */
                for (i = 0; i < shmalloced; i++)
                        if (shmsegs[i].u.shm_perm.mode & SHMSEG_FREE)
                                break;
                if (i == shmalloced)
                        return (ENOSPC);
                segnum = i;
        } else  {
                segnum = shm_last_free;
                shm_last_free = -1;
        }
        KASSERT(segnum >= 0 && segnum < shmalloced,
            ("segnum %d shmalloced %d", segnum, shmalloced));
        shmseg = &shmsegs[segnum];
#ifdef RACCT
        if (racct_enable) {
                PROC_LOCK(td->td_proc);
                if (racct_add(td->td_proc, RACCT_NSHM, 1)) {
                        PROC_UNLOCK(td->td_proc);
                        return (ENOSPC);
                }
                if (racct_add(td->td_proc, RACCT_SHMSIZE, size)) {
                        racct_sub(td->td_proc, RACCT_NSHM, 1);
                        PROC_UNLOCK(td->td_proc);
                        return (ENOMEM);
                }
                PROC_UNLOCK(td->td_proc);
        }
#endif

        /*
         * We make sure that we have allocated a pager before we need
         * to.
         */
        shm_object = vm_pager_allocate(shm_use_phys ? OBJT_PHYS : OBJT_SWAP,
            0, size, VM_PROT_DEFAULT, 0, cred);
        if (shm_object == NULL) {
#ifdef RACCT
                if (racct_enable) {
                        PROC_LOCK(td->td_proc);
                        racct_sub(td->td_proc, RACCT_NSHM, 1);
                        racct_sub(td->td_proc, RACCT_SHMSIZE, size);
                        PROC_UNLOCK(td->td_proc);
                }
#endif
                return (ENOMEM);
        }

        VM_OBJECT_WLOCK(shm_object);
        vm_object_set_flag(shm_object, OBJ_SYSVSHM);
        VM_OBJECT_WUNLOCK(shm_object);

        shmseg->object = shm_object;
        shmseg->u.shm_perm.cuid = shmseg->u.shm_perm.uid = cred->cr_uid;
        shmseg->u.shm_perm.cgid = shmseg->u.shm_perm.gid = cred->cr_gid;
        shmseg->u.shm_perm.mode = (mode & ACCESSPERMS) | SHMSEG_ALLOCATED;
        shmseg->u.shm_perm.key = key;
        shmseg->u.shm_perm.seq = (shmseg->u.shm_perm.seq + 1) & 0x7fff;
        shmseg->cred = crhold(cred);
        shmseg->u.shm_segsz = size;
        shmseg->u.shm_cpid = td->td_proc->p_pid;
        shmseg->u.shm_lpid = shmseg->u.shm_nattch = 0;
        shmseg->u.shm_atime = shmseg->u.shm_dtime = 0;
#ifdef MAC
        mac_sysvshm_create(cred, shmseg);
#endif
        shmseg->u.shm_ctime = time_second;
        shm_committed += btoc(size);
        shm_nused++;
        td->td_retval[0] = IXSEQ_TO_IPCID(segnum, shmseg->u.shm_perm);

        return (0);
}

#ifndef _SYS_SYSPROTO_H_
struct shmget_args {
        key_t key;
        size_t size;
        int shmflg;
};
#endif
int
sys_shmget(struct thread *td, struct shmget_args *uap)
{
        int segnum, mode;
        int error;

        if (shm_find_prison(td->td_ucred) == NULL)
                return (ENOSYS);
        mode = uap->shmflg & ACCESSPERMS;
        SYSVSHM_LOCK();
        if (uap->key == IPC_PRIVATE) {
                error = shmget_allocate_segment(td, uap->key, uap->size, mode);
        } else {
                segnum = shm_find_segment_by_key(td->td_ucred->cr_prison,
                    uap->key);
                if (segnum >= 0)
                        error = shmget_existing(td, uap->size, uap->shmflg,
                            mode, segnum);
                else if ((uap->shmflg & IPC_CREAT) == 0)
                        error = ENOENT;
                else
                        error = shmget_allocate_segment(td, uap->key,
                            uap->size, mode);
        }
        SYSVSHM_UNLOCK();
        return (error);
}

#ifdef SYSVSHM
void
shmfork(struct proc *p1, struct proc *p2)
#else
static void
shmfork_myhook(struct proc *p1, struct proc *p2)
#endif
{
        struct shmmap_state *shmmap_s;
        size_t size;
        int i;

        SYSVSHM_LOCK();
        size = shminfo.shmseg * sizeof(struct shmmap_state);
        shmmap_s = malloc(size, M_SHM, M_WAITOK);
        bcopy(p1->p_vmspace->vm_shm, shmmap_s, size);
        p2->p_vmspace->vm_shm = shmmap_s;
        for (i = 0; i < shminfo.shmseg; i++, shmmap_s++) {
                if (shmmap_s->shmid != -1) {
                        KASSERT(IPCID_TO_IX(shmmap_s->shmid) >= 0 &&
                            IPCID_TO_IX(shmmap_s->shmid) < shmalloced,
                            ("segnum %d shmalloced %d",
                            IPCID_TO_IX(shmmap_s->shmid), shmalloced));
                        shmsegs[IPCID_TO_IX(shmmap_s->shmid)].u.shm_nattch++;
                }
        }
        SYSVSHM_UNLOCK();
}

#ifdef SYSVSHM
void
shmexit(struct vmspace *vm)
#else
static void
shmexit_myhook(struct vmspace *vm)
#endif
{
        struct shmmap_state *base, *shm;
        int i;

        base = vm->vm_shm;
        if (base != NULL) {
                vm->vm_shm = NULL;
                SYSVSHM_LOCK();
                for (i = 0, shm = base; i < shminfo.shmseg; i++, shm++) {
                        if (shm->shmid != -1)
                                shm_delete_mapping(vm, shm);
                }
                SYSVSHM_UNLOCK();
                free(base, M_SHM);
        }
}

#ifdef SYSVSHM
void
shmobjinfo(vm_object_t obj, key_t *key, unsigned short *seq)
#else
static void
shmobjinfo_myhook(vm_object_t obj, key_t *key, unsigned short *seq)
#endif
{
        int i;

        *key = 0;       /* For statically compiled-in sysv_shm.c */
        *seq = 0;
        SYSVSHM_LOCK();
        for (i = 0; i < shmalloced; i++) {
                if (shmsegs[i].object == obj) {
                        *key = shmsegs[i].u.shm_perm.key;
                        *seq = shmsegs[i].u.shm_perm.seq;
                        break;
                }
        }
        SYSVSHM_UNLOCK();
}

static void
shmrealloc(void)
{
        struct shmid_kernel *newsegs;
        int i;

        SYSVSHM_ASSERT_LOCKED();

        if (shmalloced >= shminfo.shmmni)
                return;

        newsegs = malloc(shminfo.shmmni * sizeof(*newsegs), M_SHM,
            M_WAITOK | M_ZERO);
        for (i = 0; i < shmalloced; i++)
                bcopy(&shmsegs[i], &newsegs[i], sizeof(newsegs[0]));
        for (; i < shminfo.shmmni; i++) {
                newsegs[i].u.shm_perm.mode = SHMSEG_FREE;
                newsegs[i].u.shm_perm.seq = 0;
#ifdef MAC
                mac_sysvshm_init(&newsegs[i]);
#endif
        }
        free(shmsegs, M_SHM);
        shmsegs = newsegs;
        shmalloced = shminfo.shmmni;
}

static struct syscall_helper_data shm_syscalls[] = {
        SYSCALL_INIT_HELPER(shmat),
        SYSCALL_INIT_HELPER(shmctl),
        SYSCALL_INIT_HELPER(shmdt),
        SYSCALL_INIT_HELPER(shmget),
#if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
    defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
        SYSCALL_INIT_HELPER_COMPAT(freebsd7_shmctl),
#endif
#if defined(__i386__) && (defined(COMPAT_FREEBSD4) || defined(COMPAT_43))
        SYSCALL_INIT_HELPER(shmsys),
#endif
        SYSCALL_INIT_LAST
};

#ifdef COMPAT_FREEBSD32
#include <compat/freebsd32/freebsd32.h>
#include <compat/freebsd32/freebsd32_ipc.h>
#include <compat/freebsd32/freebsd32_proto.h>
#include <compat/freebsd32/freebsd32_signal.h>
#include <compat/freebsd32/freebsd32_syscall.h>
#include <compat/freebsd32/freebsd32_util.h>

static struct syscall_helper_data shm32_syscalls[] = {
        SYSCALL32_INIT_HELPER_COMPAT(shmat),
        SYSCALL32_INIT_HELPER_COMPAT(shmdt),
        SYSCALL32_INIT_HELPER_COMPAT(shmget),
        SYSCALL32_INIT_HELPER(freebsd32_shmsys),
        SYSCALL32_INIT_HELPER(freebsd32_shmctl),
#if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
    defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
        SYSCALL32_INIT_HELPER(freebsd7_freebsd32_shmctl),
#endif
        SYSCALL_INIT_LAST
};
#endif

static int
shminit(void)
{
        struct prison *pr;
        void **rsv;
        int i, error;
        osd_method_t methods[PR_MAXMETHOD] = {
            [PR_METHOD_CHECK] =         shm_prison_check,
            [PR_METHOD_SET] =           shm_prison_set,
            [PR_METHOD_GET] =           shm_prison_get,
            [PR_METHOD_REMOVE] =        shm_prison_remove,
        };

#ifndef BURN_BRIDGES
        if (TUNABLE_ULONG_FETCH("kern.ipc.shmmaxpgs", &shminfo.shmall) != 0)
                printf("kern.ipc.shmmaxpgs is now called kern.ipc.shmall!\n");
#endif
        if (shminfo.shmmax == SHMMAX) {
                /* Initialize shmmax dealing with possible overflow. */
                for (i = PAGE_SIZE; i != 0; i--) {
                        shminfo.shmmax = shminfo.shmall * i;
                        if ((shminfo.shmmax / shminfo.shmall) == (u_long)i)
                                break;
                }
        }
        shmalloced = shminfo.shmmni;
        shmsegs = malloc(shmalloced * sizeof(shmsegs[0]), M_SHM,
            M_WAITOK|M_ZERO);
        for (i = 0; i < shmalloced; i++) {
                shmsegs[i].u.shm_perm.mode = SHMSEG_FREE;
                shmsegs[i].u.shm_perm.seq = 0;
#ifdef MAC
                mac_sysvshm_init(&shmsegs[i]);
#endif
        }
        shm_last_free = 0;
        shm_nused = 0;
        shm_committed = 0;
        sx_init(&sysvshmsx, "sysvshmsx");
#ifndef SYSVSHM
        shmexit_hook = &shmexit_myhook;
        shmfork_hook = &shmfork_myhook;
        shmobjinfo_hook = &shmobjinfo_myhook;
#endif

        /* Set current prisons according to their allow.sysvipc. */
        shm_prison_slot = osd_jail_register(NULL, methods);
        rsv = osd_reserve(shm_prison_slot);
        prison_lock(&prison0);
        (void)osd_jail_set_reserved(&prison0, shm_prison_slot, rsv, &prison0);
        prison_unlock(&prison0);
        rsv = NULL;
        sx_slock(&allprison_lock);
        TAILQ_FOREACH(pr, &allprison, pr_list) {
                if (rsv == NULL)
                        rsv = osd_reserve(shm_prison_slot);
                prison_lock(pr);
                if (pr->pr_allow & PR_ALLOW_SYSVIPC) {
                        (void)osd_jail_set_reserved(pr, shm_prison_slot, rsv,
                            &prison0);
                        rsv = NULL;
                }
                prison_unlock(pr);
        }
        if (rsv != NULL)
                osd_free_reserved(rsv);
        sx_sunlock(&allprison_lock);

        error = syscall_helper_register(shm_syscalls, SY_THR_STATIC_KLD);
        if (error != 0)
                return (error);
#ifdef COMPAT_FREEBSD32
        error = syscall32_helper_register(shm32_syscalls, SY_THR_STATIC_KLD);
        if (error != 0)
                return (error);
#endif
        return (0);
}

static int
shmunload(void)
{
        int i;

        if (shm_nused > 0)
                return (EBUSY);

#ifdef COMPAT_FREEBSD32
        syscall32_helper_unregister(shm32_syscalls);
#endif
        syscall_helper_unregister(shm_syscalls);
        if (shm_prison_slot != 0)
                osd_jail_deregister(shm_prison_slot);

        for (i = 0; i < shmalloced; i++) {
#ifdef MAC
                mac_sysvshm_destroy(&shmsegs[i]);
#endif
                /*
                 * Objects might be still mapped into the processes
                 * address spaces.  Actual free would happen on the
                 * last mapping destruction.
                 */
                if (shmsegs[i].u.shm_perm.mode != SHMSEG_FREE)
                        vm_object_deallocate(shmsegs[i].object);
        }
        free(shmsegs, M_SHM);
#ifndef SYSVSHM
        shmexit_hook = NULL;
        shmfork_hook = NULL;
        shmobjinfo_hook = NULL;
#endif
        sx_destroy(&sysvshmsx);
        return (0);
}

static int
sysctl_shmsegs(SYSCTL_HANDLER_ARGS)
{
        struct shmid_kernel tshmseg;
#ifdef COMPAT_FREEBSD32
        struct shmid_kernel32 tshmseg32;
#endif
        struct prison *pr, *rpr;
        void *outaddr;
        size_t outsize;
        int error, i;

        SYSVSHM_LOCK();
        pr = req->td->td_ucred->cr_prison;
        rpr = shm_find_prison(req->td->td_ucred);
        error = 0;
        for (i = 0; i < shmalloced; i++) {
                if ((shmsegs[i].u.shm_perm.mode & SHMSEG_ALLOCATED) == 0 ||
                    rpr == NULL || shm_prison_cansee(rpr, &shmsegs[i]) != 0) {
                        bzero(&tshmseg, sizeof(tshmseg));
                        tshmseg.u.shm_perm.mode = SHMSEG_FREE;
                } else {
                        tshmseg = shmsegs[i];
                        if (tshmseg.cred->cr_prison != pr)
                                tshmseg.u.shm_perm.key = IPC_PRIVATE;
                }
#ifdef COMPAT_FREEBSD32
                if (SV_CURPROC_FLAG(SV_ILP32)) {
                        bzero(&tshmseg32, sizeof(tshmseg32));
                        freebsd32_ipcperm_out(&tshmseg.u.shm_perm,
                            &tshmseg32.u.shm_perm);
                        CP(tshmseg, tshmseg32, u.shm_segsz);
                        CP(tshmseg, tshmseg32, u.shm_lpid);
                        CP(tshmseg, tshmseg32, u.shm_cpid);
                        CP(tshmseg, tshmseg32, u.shm_nattch);
                        CP(tshmseg, tshmseg32, u.shm_atime);
                        CP(tshmseg, tshmseg32, u.shm_dtime);
                        CP(tshmseg, tshmseg32, u.shm_ctime);
                        /* Don't copy object, label, or cred */
                        outaddr = &tshmseg32;
                        outsize = sizeof(tshmseg32);
                } else
#endif
                {
                        tshmseg.object = NULL;
                        tshmseg.label = NULL;
                        tshmseg.cred = NULL;
                        outaddr = &tshmseg;
                        outsize = sizeof(tshmseg);
                }
                error = SYSCTL_OUT(req, outaddr, outsize);
                if (error != 0)
                        break;
        }
        SYSVSHM_UNLOCK();
        return (error);
}

int
kern_get_shmsegs(struct thread *td, struct shmid_kernel **res, size_t *sz)
{
        struct shmid_kernel *pshmseg;
        struct prison *pr, *rpr;
        int i;

        SYSVSHM_LOCK();
        *sz = shmalloced;
        if (res == NULL)
                goto out;

        pr = td->td_ucred->cr_prison;
        rpr = shm_find_prison(td->td_ucred);
        *res = malloc(sizeof(struct shmid_kernel) * shmalloced, M_TEMP,
            M_WAITOK);
        for (i = 0; i < shmalloced; i++) {
                pshmseg = &(*res)[i];
                if ((shmsegs[i].u.shm_perm.mode & SHMSEG_ALLOCATED) == 0 ||
                    rpr == NULL || shm_prison_cansee(rpr, &shmsegs[i]) != 0) {
                        bzero(pshmseg, sizeof(*pshmseg));
                        pshmseg->u.shm_perm.mode = SHMSEG_FREE;
                } else {
                        *pshmseg = shmsegs[i];
                        if (pshmseg->cred->cr_prison != pr)
                                pshmseg->u.shm_perm.key = IPC_PRIVATE;
                }
                pshmseg->object = NULL;
                pshmseg->label = NULL;
                pshmseg->cred = NULL;
        }
out:
        SYSVSHM_UNLOCK();
        return (0);
}

static int
shm_prison_check(void *obj, void *data)
{
        struct prison *pr = obj;
        struct prison *prpr;
        struct vfsoptlist *opts = data;
        int error, jsys;

        /*
         * sysvshm is a jailsys integer.
         * It must be "disable" if the parent jail is disabled.
         */
        error = vfs_copyopt(opts, "sysvshm", &jsys, sizeof(jsys));
        if (error != ENOENT) {
                if (error != 0)
                        return (error);
                switch (jsys) {
                case JAIL_SYS_DISABLE:
                        break;
                case JAIL_SYS_NEW:
                case JAIL_SYS_INHERIT:
                        prison_lock(pr->pr_parent);
                        prpr = osd_jail_get(pr->pr_parent, shm_prison_slot);
                        prison_unlock(pr->pr_parent);
                        if (prpr == NULL)
                                return (EPERM);
                        break;
                default:
                        return (EINVAL);
                }
        }

        return (0);
}

static int
shm_prison_set(void *obj, void *data)
{
        struct prison *pr = obj;
        struct prison *tpr, *orpr, *nrpr, *trpr;
        struct vfsoptlist *opts = data;
        void *rsv;
        int jsys, descend;

        /*
         * sysvshm controls which jail is the root of the associated segments
         * (this jail or same as the parent), or if the feature is available
         * at all.
         */
        if (vfs_copyopt(opts, "sysvshm", &jsys, sizeof(jsys)) == ENOENT)
                jsys = vfs_flagopt(opts, "allow.sysvipc", NULL, 0)
                    ? JAIL_SYS_INHERIT
                    : vfs_flagopt(opts, "allow.nosysvipc", NULL, 0)
                    ? JAIL_SYS_DISABLE
                    : -1;
        if (jsys == JAIL_SYS_DISABLE) {
                prison_lock(pr);
                orpr = osd_jail_get(pr, shm_prison_slot);
                if (orpr != NULL)
                        osd_jail_del(pr, shm_prison_slot);
                prison_unlock(pr);
                if (orpr != NULL) {
                        if (orpr == pr)
                                shm_prison_cleanup(pr);
                        /* Disable all child jails as well. */
                        FOREACH_PRISON_DESCENDANT(pr, tpr, descend) {
                                prison_lock(tpr);
                                trpr = osd_jail_get(tpr, shm_prison_slot);
                                if (trpr != NULL) {
                                        osd_jail_del(tpr, shm_prison_slot);
                                        prison_unlock(tpr);
                                        if (trpr == tpr)
                                                shm_prison_cleanup(tpr);
                                } else {
                                        prison_unlock(tpr);
                                        descend = 0;
                                }
                        }
                }
        } else if (jsys != -1) {
                if (jsys == JAIL_SYS_NEW)
                        nrpr = pr;
                else {
                        prison_lock(pr->pr_parent);
                        nrpr = osd_jail_get(pr->pr_parent, shm_prison_slot);
                        prison_unlock(pr->pr_parent);
                }
                rsv = osd_reserve(shm_prison_slot);
                prison_lock(pr);
                orpr = osd_jail_get(pr, shm_prison_slot);
                if (orpr != nrpr)
                        (void)osd_jail_set_reserved(pr, shm_prison_slot, rsv,
                            nrpr);
                else
                        osd_free_reserved(rsv);
                prison_unlock(pr);
                if (orpr != nrpr) {
                        if (orpr == pr)
                                shm_prison_cleanup(pr);
                        if (orpr != NULL) {
                                /* Change child jails matching the old root, */
                                FOREACH_PRISON_DESCENDANT(pr, tpr, descend) {
                                        prison_lock(tpr);
                                        trpr = osd_jail_get(tpr,
                                            shm_prison_slot);
                                        if (trpr == orpr) {
                                                (void)osd_jail_set(tpr,
                                                    shm_prison_slot, nrpr);
                                                prison_unlock(tpr);
                                                if (trpr == tpr)
                                                        shm_prison_cleanup(tpr);
                                        } else {
                                                prison_unlock(tpr);
                                                descend = 0;
                                        }
                                }
                        }
                }
        }

        return (0);
}

static int
shm_prison_get(void *obj, void *data)
{
        struct prison *pr = obj;
        struct prison *rpr;
        struct vfsoptlist *opts = data;
        int error, jsys;

        /* Set sysvshm based on the jail's root prison. */
        prison_lock(pr);
        rpr = osd_jail_get(pr, shm_prison_slot);
        prison_unlock(pr);
        jsys = rpr == NULL ? JAIL_SYS_DISABLE
            : rpr == pr ? JAIL_SYS_NEW : JAIL_SYS_INHERIT;
        error = vfs_setopt(opts, "sysvshm", &jsys, sizeof(jsys));
        if (error == ENOENT)
                error = 0;
        return (error);
}

static int
shm_prison_remove(void *obj, void *data __unused)
{
        struct prison *pr = obj;
        struct prison *rpr;

        SYSVSHM_LOCK();
        prison_lock(pr);
        rpr = osd_jail_get(pr, shm_prison_slot);
        prison_unlock(pr);
        if (rpr == pr)
                shm_prison_cleanup(pr);
        SYSVSHM_UNLOCK();
        return (0);
}

static void
shm_prison_cleanup(struct prison *pr)
{
        struct shmid_kernel *shmseg;
        int i;

        /* Remove any segments that belong to this jail. */
        for (i = 0; i < shmalloced; i++) {
                shmseg = &shmsegs[i];
                if ((shmseg->u.shm_perm.mode & SHMSEG_ALLOCATED) &&
                    shmseg->cred != NULL && shmseg->cred->cr_prison == pr) {
                        shm_remove(shmseg, i);
                }
        }
}

SYSCTL_JAIL_PARAM_SYS_NODE(sysvshm, CTLFLAG_RW, "SYSV shared memory");

#if defined(__i386__) && (defined(COMPAT_FREEBSD4) || defined(COMPAT_43))
struct oshmid_ds {
        struct  ipc_perm_old shm_perm;  /* operation perms */
        int     shm_segsz;              /* size of segment (bytes) */
        u_short shm_cpid;               /* pid, creator */
        u_short shm_lpid;               /* pid, last operation */
        short   shm_nattch;             /* no. of current attaches */
        time_t  shm_atime;              /* last attach time */
        time_t  shm_dtime;              /* last detach time */
        time_t  shm_ctime;              /* last change time */
        void    *shm_handle;            /* internal handle for shm segment */
};

struct oshmctl_args {
        int shmid;
        int cmd;
        struct oshmid_ds *ubuf;
};

static int
oshmctl(struct thread *td, struct oshmctl_args *uap)
{
#ifdef COMPAT_43
        int error = 0;
        struct prison *rpr;
        struct shmid_kernel *shmseg;
        struct oshmid_ds outbuf;

        rpr = shm_find_prison(td->td_ucred);
        if (rpr == NULL)
                return (ENOSYS);
        if (uap->cmd != IPC_STAT) {
                return (freebsd7_shmctl(td,
                    (struct freebsd7_shmctl_args *)uap));
        }
        SYSVSHM_LOCK();
        shmseg = shm_find_segment(rpr, uap->shmid, true);
        if (shmseg == NULL) {
                SYSVSHM_UNLOCK();
                return (EINVAL);
        }
        error = ipcperm(td, &shmseg->u.shm_perm, IPC_R);
        if (error != 0) {
                SYSVSHM_UNLOCK();
                return (error);
        }
#ifdef MAC
        error = mac_sysvshm_check_shmctl(td->td_ucred, shmseg, uap->cmd);
        if (error != 0) {
                SYSVSHM_UNLOCK();
                return (error);
        }
#endif
        ipcperm_new2old(&shmseg->u.shm_perm, &outbuf.shm_perm);
        outbuf.shm_segsz = shmseg->u.shm_segsz;
        outbuf.shm_cpid = shmseg->u.shm_cpid;
        outbuf.shm_lpid = shmseg->u.shm_lpid;
        outbuf.shm_nattch = shmseg->u.shm_nattch;
        outbuf.shm_atime = shmseg->u.shm_atime;
        outbuf.shm_dtime = shmseg->u.shm_dtime;
        outbuf.shm_ctime = shmseg->u.shm_ctime;
        outbuf.shm_handle = shmseg->object;
        SYSVSHM_UNLOCK();
        return (copyout(&outbuf, uap->ubuf, sizeof(outbuf)));
#else
        return (EINVAL);
#endif
}

/* XXX casting to (sy_call_t *) is bogus, as usual. */
static sy_call_t *shmcalls[] = {
        (sy_call_t *)sys_shmat, (sy_call_t *)oshmctl,
        (sy_call_t *)sys_shmdt, (sy_call_t *)sys_shmget,
        (sy_call_t *)freebsd7_shmctl
};

#ifndef _SYS_SYSPROTO_H_
/* XXX actually varargs. */
struct shmsys_args {
        int     which;
        int     a2;
        int     a3;
        int     a4;
};
#endif
int
sys_shmsys(struct thread *td, struct shmsys_args *uap)
{

        AUDIT_ARG_SVIPC_WHICH(uap->which);
        if (uap->which < 0 || uap->which >= nitems(shmcalls))
                return (EINVAL);
        return ((*shmcalls[uap->which])(td, &uap->a2));
}

#endif  /* i386 && (COMPAT_FREEBSD4 || COMPAT_43) */

#ifdef COMPAT_FREEBSD32

int
freebsd32_shmsys(struct thread *td, struct freebsd32_shmsys_args *uap)
{

#if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
    defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
        AUDIT_ARG_SVIPC_WHICH(uap->which);
        switch (uap->which) {
        case 0: {       /* shmat */
                struct shmat_args ap;

                ap.shmid = uap->a2;
                ap.shmaddr = PTRIN(uap->a3);
                ap.shmflg = uap->a4;
                return (sysent[SYS_shmat].sy_call(td, &ap));
        }
        case 2: {       /* shmdt */
                struct shmdt_args ap;

                ap.shmaddr = PTRIN(uap->a2);
                return (sysent[SYS_shmdt].sy_call(td, &ap));
        }
        case 3: {       /* shmget */
                struct shmget_args ap;

                ap.key = uap->a2;
                ap.size = uap->a3;
                ap.shmflg = uap->a4;
                return (sysent[SYS_shmget].sy_call(td, &ap));
        }
        case 4: {       /* shmctl */
                struct freebsd7_freebsd32_shmctl_args ap;

                ap.shmid = uap->a2;
                ap.cmd = uap->a3;
                ap.buf = PTRIN(uap->a4);
                return (freebsd7_freebsd32_shmctl(td, &ap));
        }
        case 1:         /* oshmctl */
        default:
                return (EINVAL);
        }
#else
        return (kern_nosys(td, 0));
#endif
}

#if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
    defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
int
freebsd7_freebsd32_shmctl(struct thread *td,
    struct freebsd7_freebsd32_shmctl_args *uap)
{
        int error;
        union {
                struct shmid_ds shmid_ds;
                struct shm_info shm_info;
                struct shminfo shminfo;
        } u;
        union {
                struct shmid_ds_old32 shmid_ds32;
                struct shm_info32 shm_info32;
                struct shminfo32 shminfo32;
        } u32;
        size_t sz;

        if (uap->cmd == IPC_SET) {
                if ((error = copyin(uap->buf, &u32.shmid_ds32,
                    sizeof(u32.shmid_ds32))))
                        goto done;
                freebsd32_ipcperm_old_in(&u32.shmid_ds32.shm_perm,
                    &u.shmid_ds.shm_perm);
                CP(u32.shmid_ds32, u.shmid_ds, shm_segsz);
                CP(u32.shmid_ds32, u.shmid_ds, shm_lpid);
                CP(u32.shmid_ds32, u.shmid_ds, shm_cpid);
                CP(u32.shmid_ds32, u.shmid_ds, shm_nattch);
                CP(u32.shmid_ds32, u.shmid_ds, shm_atime);
                CP(u32.shmid_ds32, u.shmid_ds, shm_dtime);
                CP(u32.shmid_ds32, u.shmid_ds, shm_ctime);
        }

        error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&u, &sz);
        if (error)
                goto done;

        /* Cases in which we need to copyout */
        switch (uap->cmd) {
        case IPC_INFO:
                CP(u.shminfo, u32.shminfo32, shmmax);
                CP(u.shminfo, u32.shminfo32, shmmin);
                CP(u.shminfo, u32.shminfo32, shmmni);
                CP(u.shminfo, u32.shminfo32, shmseg);
                CP(u.shminfo, u32.shminfo32, shmall);
                error = copyout(&u32.shminfo32, uap->buf,
                    sizeof(u32.shminfo32));
                break;
        case SHM_INFO:
                CP(u.shm_info, u32.shm_info32, used_ids);
                CP(u.shm_info, u32.shm_info32, shm_rss);
                CP(u.shm_info, u32.shm_info32, shm_tot);
                CP(u.shm_info, u32.shm_info32, shm_swp);
                CP(u.shm_info, u32.shm_info32, swap_attempts);
                CP(u.shm_info, u32.shm_info32, swap_successes);
                error = copyout(&u32.shm_info32, uap->buf,
                    sizeof(u32.shm_info32));
                break;
        case SHM_STAT:
        case IPC_STAT:
                memset(&u32.shmid_ds32, 0, sizeof(u32.shmid_ds32));
                freebsd32_ipcperm_old_out(&u.shmid_ds.shm_perm,
                    &u32.shmid_ds32.shm_perm);
                if (u.shmid_ds.shm_segsz > INT32_MAX)
                        u32.shmid_ds32.shm_segsz = INT32_MAX;
                else
                        CP(u.shmid_ds, u32.shmid_ds32, shm_segsz);
                CP(u.shmid_ds, u32.shmid_ds32, shm_lpid);
                CP(u.shmid_ds, u32.shmid_ds32, shm_cpid);
                CP(u.shmid_ds, u32.shmid_ds32, shm_nattch);
                CP(u.shmid_ds, u32.shmid_ds32, shm_atime);
                CP(u.shmid_ds, u32.shmid_ds32, shm_dtime);
                CP(u.shmid_ds, u32.shmid_ds32, shm_ctime);
                u32.shmid_ds32.shm_internal = 0;
                error = copyout(&u32.shmid_ds32, uap->buf,
                    sizeof(u32.shmid_ds32));
                break;
        }

done:
        if (error) {
                /* Invalidate the return value */
                td->td_retval[0] = -1;
        }
        return (error);
}
#endif

int
freebsd32_shmctl(struct thread *td, struct freebsd32_shmctl_args *uap)
{
        int error;
        union {
                struct shmid_ds shmid_ds;
                struct shm_info shm_info;
                struct shminfo shminfo;
        } u;
        union {
                struct shmid_ds32 shmid_ds32;
                struct shm_info32 shm_info32;
                struct shminfo32 shminfo32;
        } u32;
        size_t sz;

        if (uap->cmd == IPC_SET) {
                if ((error = copyin(uap->buf, &u32.shmid_ds32,
                    sizeof(u32.shmid_ds32))))
                        goto done;
                freebsd32_ipcperm_in(&u32.shmid_ds32.shm_perm,
                    &u.shmid_ds.shm_perm);
                CP(u32.shmid_ds32, u.shmid_ds, shm_segsz);
                CP(u32.shmid_ds32, u.shmid_ds, shm_lpid);
                CP(u32.shmid_ds32, u.shmid_ds, shm_cpid);
                CP(u32.shmid_ds32, u.shmid_ds, shm_nattch);
                CP(u32.shmid_ds32, u.shmid_ds, shm_atime);
                CP(u32.shmid_ds32, u.shmid_ds, shm_dtime);
                CP(u32.shmid_ds32, u.shmid_ds, shm_ctime);
        }

        error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&u, &sz);
        if (error)
                goto done;

        /* Cases in which we need to copyout */
        switch (uap->cmd) {
        case IPC_INFO:
                CP(u.shminfo, u32.shminfo32, shmmax);
                CP(u.shminfo, u32.shminfo32, shmmin);
                CP(u.shminfo, u32.shminfo32, shmmni);
                CP(u.shminfo, u32.shminfo32, shmseg);
                CP(u.shminfo, u32.shminfo32, shmall);
                error = copyout(&u32.shminfo32, uap->buf,
                    sizeof(u32.shminfo32));
                break;
        case SHM_INFO:
                CP(u.shm_info, u32.shm_info32, used_ids);
                CP(u.shm_info, u32.shm_info32, shm_rss);
                CP(u.shm_info, u32.shm_info32, shm_tot);
                CP(u.shm_info, u32.shm_info32, shm_swp);
                CP(u.shm_info, u32.shm_info32, swap_attempts);
                CP(u.shm_info, u32.shm_info32, swap_successes);
                error = copyout(&u32.shm_info32, uap->buf,
                    sizeof(u32.shm_info32));
                break;
        case SHM_STAT:
        case IPC_STAT:
                freebsd32_ipcperm_out(&u.shmid_ds.shm_perm,
                    &u32.shmid_ds32.shm_perm);
                if (u.shmid_ds.shm_segsz > INT32_MAX)
                        u32.shmid_ds32.shm_segsz = INT32_MAX;
                else
                        CP(u.shmid_ds, u32.shmid_ds32, shm_segsz);
                CP(u.shmid_ds, u32.shmid_ds32, shm_lpid);
                CP(u.shmid_ds, u32.shmid_ds32, shm_cpid);
                CP(u.shmid_ds, u32.shmid_ds32, shm_nattch);
                CP(u.shmid_ds, u32.shmid_ds32, shm_atime);
                CP(u.shmid_ds, u32.shmid_ds32, shm_dtime);
                CP(u.shmid_ds, u32.shmid_ds32, shm_ctime);
                error = copyout(&u32.shmid_ds32, uap->buf,
                    sizeof(u32.shmid_ds32));
                break;
        }

done:
        if (error) {
                /* Invalidate the return value */
                td->td_retval[0] = -1;
        }
        return (error);
}
#endif

#if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
    defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)

#ifndef _SYS_SYSPROTO_H_
struct freebsd7_shmctl_args {
        int shmid;
        int cmd;
        struct shmid_ds_old *buf;
};
#endif
int
freebsd7_shmctl(struct thread *td, struct freebsd7_shmctl_args *uap)
{
        int error;
        struct shmid_ds_old old;
        struct shmid_ds buf;
        size_t bufsz;

        /*
         * The only reason IPC_INFO, SHM_INFO, SHM_STAT exists is to support
         * Linux binaries.  If we see the call come through the FreeBSD ABI,
         * return an error back to the user since we do not to support this.
         */
        if (uap->cmd == IPC_INFO || uap->cmd == SHM_INFO ||
            uap->cmd == SHM_STAT)
                return (EINVAL);

        /* IPC_SET needs to copyin the buffer before calling kern_shmctl */
        if (uap->cmd == IPC_SET) {
                if ((error = copyin(uap->buf, &old, sizeof(old))))
                        goto done;
                ipcperm_old2new(&old.shm_perm, &buf.shm_perm);
                CP(old, buf, shm_segsz);
                CP(old, buf, shm_lpid);
                CP(old, buf, shm_cpid);
                CP(old, buf, shm_nattch);
                CP(old, buf, shm_atime);
                CP(old, buf, shm_dtime);
                CP(old, buf, shm_ctime);
        }

        error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&buf, &bufsz);
        if (error)
                goto done;

        /* Cases in which we need to copyout */
        switch (uap->cmd) {
        case IPC_STAT:
                memset(&old, 0, sizeof(old));
                ipcperm_new2old(&buf.shm_perm, &old.shm_perm);
                if (buf.shm_segsz > INT_MAX)
                        old.shm_segsz = INT_MAX;
                else
                        CP(buf, old, shm_segsz);
                CP(buf, old, shm_lpid);
                CP(buf, old, shm_cpid);
                if (buf.shm_nattch > SHRT_MAX)
                        old.shm_nattch = SHRT_MAX;
                else
                        CP(buf, old, shm_nattch);
                CP(buf, old, shm_atime);
                CP(buf, old, shm_dtime);
                CP(buf, old, shm_ctime);
                old.shm_internal = NULL;
                error = copyout(&old, uap->buf, sizeof(old));
                break;
        }

done:
        if (error) {
                /* Invalidate the return value */
                td->td_retval[0] = -1;
        }
        return (error);
}

#endif  /* COMPAT_FREEBSD4 || COMPAT_FREEBSD5 || COMPAT_FREEBSD6 ||
           COMPAT_FREEBSD7 */

static int
sysvshm_modload(struct module *module, int cmd, void *arg)
{
        int error = 0;

        switch (cmd) {
        case MOD_LOAD:
                error = shminit();
                if (error != 0)
                        shmunload();
                break;
        case MOD_UNLOAD:
                error = shmunload();
                break;
        case MOD_SHUTDOWN:
                break;
        default:
                error = EINVAL;
                break;
        }
        return (error);
}

static moduledata_t sysvshm_mod = {
        "sysvshm",
        &sysvshm_modload,
        NULL
};

DECLARE_MODULE(sysvshm, sysvshm_mod, SI_SUB_SYSV_SHM, SI_ORDER_FIRST);
MODULE_VERSION(sysvshm, 1);