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bcf11e8d00
and used in a large number of files, but also because an increasing number of incorrect uses of MAC calls were sneaking in due to copy-and-paste of MAC-aware code without the associated opt_mac.h include. Discussed with: pjd
956 lines
21 KiB
C
956 lines
21 KiB
C
/*-
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* Copyright (c) 2002 Alfred Perlstein <alfred@FreeBSD.org>
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* Copyright (c) 2003-2005 SPARTA, Inc.
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* Copyright (c) 2005 Robert N. M. Watson
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* All rights reserved.
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*
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* This software was developed for the FreeBSD Project in part by Network
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* Associates Laboratories, the Security Research Division of Network
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* Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"),
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* as part of the DARPA CHATS research program.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include "opt_posix.h"
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#include <sys/param.h>
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#include <sys/condvar.h>
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#include <sys/fcntl.h>
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#include <sys/file.h>
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#include <sys/filedesc.h>
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#include <sys/fnv_hash.h>
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#include <sys/kernel.h>
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#include <sys/ksem.h>
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#include <sys/lock.h>
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#include <sys/malloc.h>
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#include <sys/module.h>
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#include <sys/mutex.h>
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#include <sys/priv.h>
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#include <sys/proc.h>
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#include <sys/posix4.h>
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#include <sys/semaphore.h>
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#include <sys/_semaphore.h>
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#include <sys/stat.h>
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#include <sys/syscall.h>
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#include <sys/syscallsubr.h>
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#include <sys/sysctl.h>
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#include <sys/sysent.h>
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#include <sys/sysproto.h>
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#include <sys/systm.h>
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#include <sys/sx.h>
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#include <sys/vnode.h>
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#include <security/mac/mac_framework.h>
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/*
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* TODO
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*
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* - Resource limits?
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* - Update fstat(1)
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* - Replace global sem_lock with mtx_pool locks?
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* - Add a MAC check_create() hook for creating new named semaphores.
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*/
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#ifndef SEM_MAX
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#define SEM_MAX 30
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#endif
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#ifdef SEM_DEBUG
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#define DP(x) printf x
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#else
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#define DP(x)
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#endif
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struct ksem_mapping {
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char *km_path;
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Fnv32_t km_fnv;
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struct ksem *km_ksem;
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LIST_ENTRY(ksem_mapping) km_link;
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};
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static MALLOC_DEFINE(M_KSEM, "ksem", "semaphore file descriptor");
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static LIST_HEAD(, ksem_mapping) *ksem_dictionary;
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static struct sx ksem_dict_lock;
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static struct mtx ksem_count_lock;
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static struct mtx sem_lock;
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static u_long ksem_hash;
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static int ksem_dead;
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#define KSEM_HASH(fnv) (&ksem_dictionary[(fnv) & ksem_hash])
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static int nsems = 0;
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SYSCTL_DECL(_p1003_1b);
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SYSCTL_INT(_p1003_1b, OID_AUTO, nsems, CTLFLAG_RD, &nsems, 0,
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"Number of active kernel POSIX semaphores");
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static int kern_sem_wait(struct thread *td, semid_t id, int tryflag,
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struct timespec *abstime);
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static int ksem_access(struct ksem *ks, struct ucred *ucred);
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static struct ksem *ksem_alloc(struct ucred *ucred, mode_t mode,
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unsigned int value);
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static int ksem_create(struct thread *td, const char *path,
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semid_t *semidp, mode_t mode, unsigned int value,
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int flags);
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static void ksem_drop(struct ksem *ks);
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static int ksem_get(struct thread *td, semid_t id, struct file **fpp);
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static struct ksem *ksem_hold(struct ksem *ks);
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static void ksem_insert(char *path, Fnv32_t fnv, struct ksem *ks);
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static struct ksem *ksem_lookup(char *path, Fnv32_t fnv);
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static void ksem_module_destroy(void);
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static int ksem_module_init(void);
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static int ksem_remove(char *path, Fnv32_t fnv, struct ucred *ucred);
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static int sem_modload(struct module *module, int cmd, void *arg);
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static fo_rdwr_t ksem_read;
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static fo_rdwr_t ksem_write;
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static fo_truncate_t ksem_truncate;
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static fo_ioctl_t ksem_ioctl;
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static fo_poll_t ksem_poll;
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static fo_kqfilter_t ksem_kqfilter;
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static fo_stat_t ksem_stat;
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static fo_close_t ksem_closef;
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/* File descriptor operations. */
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static struct fileops ksem_ops = {
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.fo_read = ksem_read,
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.fo_write = ksem_write,
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.fo_truncate = ksem_truncate,
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.fo_ioctl = ksem_ioctl,
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.fo_poll = ksem_poll,
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.fo_kqfilter = ksem_kqfilter,
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.fo_stat = ksem_stat,
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.fo_close = ksem_closef,
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.fo_flags = DFLAG_PASSABLE
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};
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FEATURE(posix_sem, "POSIX semaphores");
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static int
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ksem_read(struct file *fp, struct uio *uio, struct ucred *active_cred,
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int flags, struct thread *td)
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{
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return (EOPNOTSUPP);
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}
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static int
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ksem_write(struct file *fp, struct uio *uio, struct ucred *active_cred,
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int flags, struct thread *td)
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{
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return (EOPNOTSUPP);
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}
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static int
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ksem_truncate(struct file *fp, off_t length, struct ucred *active_cred,
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struct thread *td)
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{
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return (EINVAL);
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}
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static int
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ksem_ioctl(struct file *fp, u_long com, void *data,
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struct ucred *active_cred, struct thread *td)
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{
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return (EOPNOTSUPP);
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}
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static int
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ksem_poll(struct file *fp, int events, struct ucred *active_cred,
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struct thread *td)
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{
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return (EOPNOTSUPP);
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}
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static int
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ksem_kqfilter(struct file *fp, struct knote *kn)
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{
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return (EOPNOTSUPP);
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}
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static int
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ksem_stat(struct file *fp, struct stat *sb, struct ucred *active_cred,
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struct thread *td)
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{
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struct ksem *ks;
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#ifdef MAC
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int error;
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#endif
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ks = fp->f_data;
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#ifdef MAC
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error = mac_posixsem_check_stat(active_cred, fp->f_cred, ks);
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if (error)
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return (error);
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#endif
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/*
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* Attempt to return sanish values for fstat() on a semaphore
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* file descriptor.
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*/
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bzero(sb, sizeof(*sb));
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sb->st_mode = S_IFREG | ks->ks_mode; /* XXX */
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sb->st_atimespec = ks->ks_atime;
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sb->st_ctimespec = ks->ks_ctime;
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sb->st_mtimespec = ks->ks_mtime;
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sb->st_birthtimespec = ks->ks_birthtime;
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sb->st_uid = ks->ks_uid;
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sb->st_gid = ks->ks_gid;
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return (0);
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}
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static int
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ksem_closef(struct file *fp, struct thread *td)
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{
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struct ksem *ks;
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ks = fp->f_data;
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fp->f_data = NULL;
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ksem_drop(ks);
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return (0);
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}
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/*
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* ksem object management including creation and reference counting
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* routines.
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*/
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static struct ksem *
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ksem_alloc(struct ucred *ucred, mode_t mode, unsigned int value)
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{
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struct ksem *ks;
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mtx_lock(&ksem_count_lock);
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if (nsems == p31b_getcfg(CTL_P1003_1B_SEM_NSEMS_MAX) || ksem_dead) {
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mtx_unlock(&ksem_count_lock);
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return (NULL);
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}
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nsems++;
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mtx_unlock(&ksem_count_lock);
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ks = malloc(sizeof(*ks), M_KSEM, M_WAITOK | M_ZERO);
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ks->ks_uid = ucred->cr_uid;
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ks->ks_gid = ucred->cr_gid;
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ks->ks_mode = mode;
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ks->ks_value = value;
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cv_init(&ks->ks_cv, "ksem");
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vfs_timestamp(&ks->ks_birthtime);
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ks->ks_atime = ks->ks_mtime = ks->ks_ctime = ks->ks_birthtime;
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refcount_init(&ks->ks_ref, 1);
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#ifdef MAC
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mac_posixsem_init(ks);
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mac_posixsem_create(ucred, ks);
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#endif
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return (ks);
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}
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static struct ksem *
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ksem_hold(struct ksem *ks)
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{
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refcount_acquire(&ks->ks_ref);
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return (ks);
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}
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static void
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ksem_drop(struct ksem *ks)
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{
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if (refcount_release(&ks->ks_ref)) {
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#ifdef MAC
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mac_posixsem_destroy(ks);
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#endif
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cv_destroy(&ks->ks_cv);
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free(ks, M_KSEM);
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mtx_lock(&ksem_count_lock);
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nsems--;
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mtx_unlock(&ksem_count_lock);
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}
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}
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/*
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* Determine if the credentials have sufficient permissions for read
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* and write access.
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*/
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static int
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ksem_access(struct ksem *ks, struct ucred *ucred)
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{
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int error;
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error = vaccess(VREG, ks->ks_mode, ks->ks_uid, ks->ks_gid,
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VREAD | VWRITE, ucred, NULL);
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if (error)
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error = priv_check_cred(ucred, PRIV_SEM_WRITE, 0);
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return (error);
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}
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/*
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* Dictionary management. We maintain an in-kernel dictionary to map
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* paths to semaphore objects. We use the FNV hash on the path to
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* store the mappings in a hash table.
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*/
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static struct ksem *
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ksem_lookup(char *path, Fnv32_t fnv)
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{
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struct ksem_mapping *map;
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LIST_FOREACH(map, KSEM_HASH(fnv), km_link) {
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if (map->km_fnv != fnv)
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continue;
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if (strcmp(map->km_path, path) == 0)
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return (map->km_ksem);
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}
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return (NULL);
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}
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static void
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ksem_insert(char *path, Fnv32_t fnv, struct ksem *ks)
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{
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struct ksem_mapping *map;
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map = malloc(sizeof(struct ksem_mapping), M_KSEM, M_WAITOK);
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map->km_path = path;
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map->km_fnv = fnv;
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map->km_ksem = ksem_hold(ks);
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LIST_INSERT_HEAD(KSEM_HASH(fnv), map, km_link);
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}
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static int
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ksem_remove(char *path, Fnv32_t fnv, struct ucred *ucred)
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{
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struct ksem_mapping *map;
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int error;
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LIST_FOREACH(map, KSEM_HASH(fnv), km_link) {
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if (map->km_fnv != fnv)
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continue;
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if (strcmp(map->km_path, path) == 0) {
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#ifdef MAC
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error = mac_posixsem_check_unlink(ucred, map->km_ksem);
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if (error)
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return (error);
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#endif
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error = ksem_access(map->km_ksem, ucred);
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if (error)
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return (error);
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LIST_REMOVE(map, km_link);
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ksem_drop(map->km_ksem);
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free(map->km_path, M_KSEM);
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free(map, M_KSEM);
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return (0);
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}
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}
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return (ENOENT);
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}
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/* Other helper routines. */
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static int
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ksem_create(struct thread *td, const char *name, semid_t *semidp, mode_t mode,
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unsigned int value, int flags)
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{
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struct filedesc *fdp;
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struct ksem *ks;
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struct file *fp;
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char *path;
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semid_t semid;
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Fnv32_t fnv;
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int error, fd;
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if (value > SEM_VALUE_MAX)
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return (EINVAL);
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fdp = td->td_proc->p_fd;
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mode = (mode & ~fdp->fd_cmask) & ACCESSPERMS;
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error = falloc(td, &fp, &fd);
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if (error) {
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if (name == NULL)
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error = ENOSPC;
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return (error);
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}
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/*
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* Go ahead and copyout the file descriptor now. This is a bit
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* premature, but it is a lot easier to handle errors as opposed
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* to later when we've possibly created a new semaphore, etc.
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*/
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semid = fd;
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error = copyout(&semid, semidp, sizeof(semid));
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if (error) {
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fdclose(fdp, fp, fd, td);
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fdrop(fp, td);
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return (error);
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}
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if (name == NULL) {
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/* Create an anonymous semaphore. */
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ks = ksem_alloc(td->td_ucred, mode, value);
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if (ks == NULL)
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error = ENOSPC;
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else
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ks->ks_flags |= KS_ANONYMOUS;
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} else {
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path = malloc(MAXPATHLEN, M_KSEM, M_WAITOK);
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error = copyinstr(name, path, MAXPATHLEN, NULL);
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/* Require paths to start with a '/' character. */
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if (error == 0 && path[0] != '/')
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error = EINVAL;
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if (error) {
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fdclose(fdp, fp, fd, td);
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fdrop(fp, td);
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free(path, M_KSEM);
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return (error);
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}
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fnv = fnv_32_str(path, FNV1_32_INIT);
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sx_xlock(&ksem_dict_lock);
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ks = ksem_lookup(path, fnv);
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if (ks == NULL) {
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/* Object does not exist, create it if requested. */
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if (flags & O_CREAT) {
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ks = ksem_alloc(td->td_ucred, mode, value);
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if (ks == NULL)
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error = ENFILE;
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else {
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ksem_insert(path, fnv, ks);
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path = NULL;
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}
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} else
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error = ENOENT;
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} else {
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/*
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* Object already exists, obtain a new
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* reference if requested and permitted.
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*/
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if ((flags & (O_CREAT | O_EXCL)) ==
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(O_CREAT | O_EXCL))
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error = EEXIST;
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else {
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#ifdef MAC
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error = mac_posixsem_check_open(td->td_ucred,
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ks);
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if (error == 0)
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#endif
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error = ksem_access(ks, td->td_ucred);
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}
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if (error == 0)
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ksem_hold(ks);
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#ifdef INVARIANTS
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else
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ks = NULL;
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#endif
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}
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sx_xunlock(&ksem_dict_lock);
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if (path)
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free(path, M_KSEM);
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}
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if (error) {
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KASSERT(ks == NULL, ("ksem_create error with a ksem"));
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fdclose(fdp, fp, fd, td);
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fdrop(fp, td);
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return (error);
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}
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KASSERT(ks != NULL, ("ksem_create w/o a ksem"));
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finit(fp, FREAD | FWRITE, DTYPE_SEM, ks, &ksem_ops);
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FILEDESC_XLOCK(fdp);
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if (fdp->fd_ofiles[fd] == fp)
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fdp->fd_ofileflags[fd] |= UF_EXCLOSE;
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FILEDESC_XUNLOCK(fdp);
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fdrop(fp, td);
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return (0);
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}
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static int
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ksem_get(struct thread *td, semid_t id, struct file **fpp)
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{
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struct ksem *ks;
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struct file *fp;
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int error;
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error = fget(td, id, &fp);
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if (error)
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return (EINVAL);
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if (fp->f_type != DTYPE_SEM) {
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fdrop(fp, td);
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return (EINVAL);
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}
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ks = fp->f_data;
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if (ks->ks_flags & KS_DEAD) {
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fdrop(fp, td);
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return (EINVAL);
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}
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*fpp = fp;
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return (0);
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}
|
|
|
|
/* System calls. */
|
|
#ifndef _SYS_SYSPROTO_H_
|
|
struct ksem_init_args {
|
|
unsigned int value;
|
|
semid_t *idp;
|
|
};
|
|
#endif
|
|
int
|
|
ksem_init(struct thread *td, struct ksem_init_args *uap)
|
|
{
|
|
|
|
return (ksem_create(td, NULL, uap->idp, S_IRWXU | S_IRWXG, uap->value,
|
|
0));
|
|
}
|
|
|
|
#ifndef _SYS_SYSPROTO_H_
|
|
struct ksem_open_args {
|
|
char *name;
|
|
int oflag;
|
|
mode_t mode;
|
|
unsigned int value;
|
|
semid_t *idp;
|
|
};
|
|
#endif
|
|
int
|
|
ksem_open(struct thread *td, struct ksem_open_args *uap)
|
|
{
|
|
|
|
DP((">>> ksem_open start, pid=%d\n", (int)td->td_proc->p_pid));
|
|
|
|
if ((uap->oflag & ~(O_CREAT | O_EXCL)) != 0)
|
|
return (EINVAL);
|
|
return (ksem_create(td, uap->name, uap->idp, uap->mode, uap->value,
|
|
uap->oflag));
|
|
}
|
|
|
|
#ifndef _SYS_SYSPROTO_H_
|
|
struct ksem_unlink_args {
|
|
char *name;
|
|
};
|
|
#endif
|
|
int
|
|
ksem_unlink(struct thread *td, struct ksem_unlink_args *uap)
|
|
{
|
|
char *path;
|
|
Fnv32_t fnv;
|
|
int error;
|
|
|
|
path = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
|
|
error = copyinstr(uap->name, path, MAXPATHLEN, NULL);
|
|
if (error) {
|
|
free(path, M_TEMP);
|
|
return (error);
|
|
}
|
|
|
|
fnv = fnv_32_str(path, FNV1_32_INIT);
|
|
sx_xlock(&ksem_dict_lock);
|
|
error = ksem_remove(path, fnv, td->td_ucred);
|
|
sx_xunlock(&ksem_dict_lock);
|
|
free(path, M_TEMP);
|
|
|
|
return (error);
|
|
}
|
|
|
|
#ifndef _SYS_SYSPROTO_H_
|
|
struct ksem_close_args {
|
|
semid_t id;
|
|
};
|
|
#endif
|
|
int
|
|
ksem_close(struct thread *td, struct ksem_close_args *uap)
|
|
{
|
|
struct ksem *ks;
|
|
struct file *fp;
|
|
int error;
|
|
|
|
error = ksem_get(td, uap->id, &fp);
|
|
if (error)
|
|
return (error);
|
|
ks = fp->f_data;
|
|
if (ks->ks_flags & KS_ANONYMOUS) {
|
|
fdrop(fp, td);
|
|
return (EINVAL);
|
|
}
|
|
error = kern_close(td, uap->id);
|
|
fdrop(fp, td);
|
|
return (error);
|
|
}
|
|
|
|
#ifndef _SYS_SYSPROTO_H_
|
|
struct ksem_post_args {
|
|
semid_t id;
|
|
};
|
|
#endif
|
|
int
|
|
ksem_post(struct thread *td, struct ksem_post_args *uap)
|
|
{
|
|
struct file *fp;
|
|
struct ksem *ks;
|
|
int error;
|
|
|
|
error = ksem_get(td, uap->id, &fp);
|
|
if (error)
|
|
return (error);
|
|
ks = fp->f_data;
|
|
|
|
mtx_lock(&sem_lock);
|
|
#ifdef MAC
|
|
error = mac_posixsem_check_post(td->td_ucred, fp->f_cred, ks);
|
|
if (error)
|
|
goto err;
|
|
#endif
|
|
if (ks->ks_value == SEM_VALUE_MAX) {
|
|
error = EOVERFLOW;
|
|
goto err;
|
|
}
|
|
++ks->ks_value;
|
|
if (ks->ks_waiters > 0)
|
|
cv_signal(&ks->ks_cv);
|
|
error = 0;
|
|
vfs_timestamp(&ks->ks_ctime);
|
|
err:
|
|
mtx_unlock(&sem_lock);
|
|
fdrop(fp, td);
|
|
return (error);
|
|
}
|
|
|
|
#ifndef _SYS_SYSPROTO_H_
|
|
struct ksem_wait_args {
|
|
semid_t id;
|
|
};
|
|
#endif
|
|
int
|
|
ksem_wait(struct thread *td, struct ksem_wait_args *uap)
|
|
{
|
|
|
|
return (kern_sem_wait(td, uap->id, 0, NULL));
|
|
}
|
|
|
|
#ifndef _SYS_SYSPROTO_H_
|
|
struct ksem_timedwait_args {
|
|
semid_t id;
|
|
const struct timespec *abstime;
|
|
};
|
|
#endif
|
|
int
|
|
ksem_timedwait(struct thread *td, struct ksem_timedwait_args *uap)
|
|
{
|
|
struct timespec abstime;
|
|
struct timespec *ts;
|
|
int error;
|
|
|
|
/*
|
|
* We allow a null timespec (wait forever).
|
|
*/
|
|
if (uap->abstime == NULL)
|
|
ts = NULL;
|
|
else {
|
|
error = copyin(uap->abstime, &abstime, sizeof(abstime));
|
|
if (error != 0)
|
|
return (error);
|
|
if (abstime.tv_nsec >= 1000000000 || abstime.tv_nsec < 0)
|
|
return (EINVAL);
|
|
ts = &abstime;
|
|
}
|
|
return (kern_sem_wait(td, uap->id, 0, ts));
|
|
}
|
|
|
|
#ifndef _SYS_SYSPROTO_H_
|
|
struct ksem_trywait_args {
|
|
semid_t id;
|
|
};
|
|
#endif
|
|
int
|
|
ksem_trywait(struct thread *td, struct ksem_trywait_args *uap)
|
|
{
|
|
|
|
return (kern_sem_wait(td, uap->id, 1, NULL));
|
|
}
|
|
|
|
static int
|
|
kern_sem_wait(struct thread *td, semid_t id, int tryflag,
|
|
struct timespec *abstime)
|
|
{
|
|
struct timespec ts1, ts2;
|
|
struct timeval tv;
|
|
struct file *fp;
|
|
struct ksem *ks;
|
|
int error;
|
|
|
|
DP((">>> kern_sem_wait entered! pid=%d\n", (int)td->td_proc->p_pid));
|
|
error = ksem_get(td, id, &fp);
|
|
if (error)
|
|
return (error);
|
|
ks = fp->f_data;
|
|
mtx_lock(&sem_lock);
|
|
DP((">>> kern_sem_wait critical section entered! pid=%d\n",
|
|
(int)td->td_proc->p_pid));
|
|
#ifdef MAC
|
|
error = mac_posixsem_check_wait(td->td_ucred, fp->f_cred, ks);
|
|
if (error) {
|
|
DP(("kern_sem_wait mac failed\n"));
|
|
goto err;
|
|
}
|
|
#endif
|
|
DP(("kern_sem_wait value = %d, tryflag %d\n", ks->ks_value, tryflag));
|
|
vfs_timestamp(&ks->ks_atime);
|
|
while (ks->ks_value == 0) {
|
|
ks->ks_waiters++;
|
|
if (tryflag != 0)
|
|
error = EAGAIN;
|
|
else if (abstime == NULL)
|
|
error = cv_wait_sig(&ks->ks_cv, &sem_lock);
|
|
else {
|
|
for (;;) {
|
|
ts1 = *abstime;
|
|
getnanotime(&ts2);
|
|
timespecsub(&ts1, &ts2);
|
|
TIMESPEC_TO_TIMEVAL(&tv, &ts1);
|
|
if (tv.tv_sec < 0) {
|
|
error = ETIMEDOUT;
|
|
break;
|
|
}
|
|
error = cv_timedwait_sig(&ks->ks_cv,
|
|
&sem_lock, tvtohz(&tv));
|
|
if (error != EWOULDBLOCK)
|
|
break;
|
|
}
|
|
}
|
|
ks->ks_waiters--;
|
|
if (error)
|
|
goto err;
|
|
}
|
|
ks->ks_value--;
|
|
DP(("kern_sem_wait value post-decrement = %d\n", ks->ks_value));
|
|
error = 0;
|
|
err:
|
|
mtx_unlock(&sem_lock);
|
|
fdrop(fp, td);
|
|
DP(("<<< kern_sem_wait leaving, pid=%d, error = %d\n",
|
|
(int)td->td_proc->p_pid, error));
|
|
return (error);
|
|
}
|
|
|
|
#ifndef _SYS_SYSPROTO_H_
|
|
struct ksem_getvalue_args {
|
|
semid_t id;
|
|
int *val;
|
|
};
|
|
#endif
|
|
int
|
|
ksem_getvalue(struct thread *td, struct ksem_getvalue_args *uap)
|
|
{
|
|
struct file *fp;
|
|
struct ksem *ks;
|
|
int error, val;
|
|
|
|
error = ksem_get(td, uap->id, &fp);
|
|
if (error)
|
|
return (error);
|
|
ks = fp->f_data;
|
|
|
|
mtx_lock(&sem_lock);
|
|
#ifdef MAC
|
|
error = mac_posixsem_check_getvalue(td->td_ucred, fp->f_cred, ks);
|
|
if (error) {
|
|
mtx_unlock(&sem_lock);
|
|
fdrop(fp, td);
|
|
return (error);
|
|
}
|
|
#endif
|
|
val = ks->ks_value;
|
|
vfs_timestamp(&ks->ks_atime);
|
|
mtx_unlock(&sem_lock);
|
|
fdrop(fp, td);
|
|
error = copyout(&val, uap->val, sizeof(val));
|
|
return (error);
|
|
}
|
|
|
|
#ifndef _SYS_SYSPROTO_H_
|
|
struct ksem_destroy_args {
|
|
semid_t id;
|
|
};
|
|
#endif
|
|
int
|
|
ksem_destroy(struct thread *td, struct ksem_destroy_args *uap)
|
|
{
|
|
struct file *fp;
|
|
struct ksem *ks;
|
|
int error;
|
|
|
|
error = ksem_get(td, uap->id, &fp);
|
|
if (error)
|
|
return (error);
|
|
ks = fp->f_data;
|
|
if (!(ks->ks_flags & KS_ANONYMOUS)) {
|
|
fdrop(fp, td);
|
|
return (EINVAL);
|
|
}
|
|
mtx_lock(&sem_lock);
|
|
if (ks->ks_waiters != 0) {
|
|
mtx_unlock(&sem_lock);
|
|
error = EBUSY;
|
|
goto err;
|
|
}
|
|
ks->ks_flags |= KS_DEAD;
|
|
mtx_unlock(&sem_lock);
|
|
|
|
error = kern_close(td, uap->id);
|
|
err:
|
|
fdrop(fp, td);
|
|
return (error);
|
|
}
|
|
|
|
#define SYSCALL_DATA(syscallname) \
|
|
static int syscallname##_syscall = SYS_##syscallname; \
|
|
static int syscallname##_registered; \
|
|
static struct sysent syscallname##_old_sysent; \
|
|
MAKE_SYSENT(syscallname);
|
|
|
|
#define SYSCALL_REGISTER(syscallname) do { \
|
|
error = syscall_register(& syscallname##_syscall, \
|
|
& syscallname##_sysent, & syscallname##_old_sysent); \
|
|
if (error) \
|
|
return (error); \
|
|
syscallname##_registered = 1; \
|
|
} while(0)
|
|
|
|
#define SYSCALL_DEREGISTER(syscallname) do { \
|
|
if (syscallname##_registered) { \
|
|
syscallname##_registered = 0; \
|
|
syscall_deregister(& syscallname##_syscall, \
|
|
& syscallname##_old_sysent); \
|
|
} \
|
|
} while(0)
|
|
|
|
SYSCALL_DATA(ksem_init);
|
|
SYSCALL_DATA(ksem_open);
|
|
SYSCALL_DATA(ksem_unlink);
|
|
SYSCALL_DATA(ksem_close);
|
|
SYSCALL_DATA(ksem_post);
|
|
SYSCALL_DATA(ksem_wait);
|
|
SYSCALL_DATA(ksem_timedwait);
|
|
SYSCALL_DATA(ksem_trywait);
|
|
SYSCALL_DATA(ksem_getvalue);
|
|
SYSCALL_DATA(ksem_destroy);
|
|
|
|
static int
|
|
ksem_module_init(void)
|
|
{
|
|
int error;
|
|
|
|
mtx_init(&sem_lock, "sem", NULL, MTX_DEF);
|
|
mtx_init(&ksem_count_lock, "ksem count", NULL, MTX_DEF);
|
|
sx_init(&ksem_dict_lock, "ksem dictionary");
|
|
ksem_dictionary = hashinit(1024, M_KSEM, &ksem_hash);
|
|
p31b_setcfg(CTL_P1003_1B_SEM_NSEMS_MAX, SEM_MAX);
|
|
p31b_setcfg(CTL_P1003_1B_SEM_VALUE_MAX, SEM_VALUE_MAX);
|
|
|
|
SYSCALL_REGISTER(ksem_init);
|
|
SYSCALL_REGISTER(ksem_open);
|
|
SYSCALL_REGISTER(ksem_unlink);
|
|
SYSCALL_REGISTER(ksem_close);
|
|
SYSCALL_REGISTER(ksem_post);
|
|
SYSCALL_REGISTER(ksem_wait);
|
|
SYSCALL_REGISTER(ksem_timedwait);
|
|
SYSCALL_REGISTER(ksem_trywait);
|
|
SYSCALL_REGISTER(ksem_getvalue);
|
|
SYSCALL_REGISTER(ksem_destroy);
|
|
return (0);
|
|
}
|
|
|
|
static void
|
|
ksem_module_destroy(void)
|
|
{
|
|
|
|
SYSCALL_DEREGISTER(ksem_init);
|
|
SYSCALL_DEREGISTER(ksem_open);
|
|
SYSCALL_DEREGISTER(ksem_unlink);
|
|
SYSCALL_DEREGISTER(ksem_close);
|
|
SYSCALL_DEREGISTER(ksem_post);
|
|
SYSCALL_DEREGISTER(ksem_wait);
|
|
SYSCALL_DEREGISTER(ksem_timedwait);
|
|
SYSCALL_DEREGISTER(ksem_trywait);
|
|
SYSCALL_DEREGISTER(ksem_getvalue);
|
|
SYSCALL_DEREGISTER(ksem_destroy);
|
|
|
|
hashdestroy(ksem_dictionary, M_KSEM, ksem_hash);
|
|
sx_destroy(&ksem_dict_lock);
|
|
mtx_destroy(&ksem_count_lock);
|
|
mtx_destroy(&sem_lock);
|
|
}
|
|
|
|
static int
|
|
sem_modload(struct module *module, int cmd, void *arg)
|
|
{
|
|
int error = 0;
|
|
|
|
switch (cmd) {
|
|
case MOD_LOAD:
|
|
error = ksem_module_init();
|
|
if (error)
|
|
ksem_module_destroy();
|
|
break;
|
|
|
|
case MOD_UNLOAD:
|
|
mtx_lock(&ksem_count_lock);
|
|
if (nsems != 0) {
|
|
error = EOPNOTSUPP;
|
|
mtx_unlock(&ksem_count_lock);
|
|
break;
|
|
}
|
|
ksem_dead = 1;
|
|
mtx_unlock(&ksem_count_lock);
|
|
ksem_module_destroy();
|
|
break;
|
|
|
|
case MOD_SHUTDOWN:
|
|
break;
|
|
default:
|
|
error = EINVAL;
|
|
break;
|
|
}
|
|
return (error);
|
|
}
|
|
|
|
static moduledata_t sem_mod = {
|
|
"sem",
|
|
&sem_modload,
|
|
NULL
|
|
};
|
|
|
|
DECLARE_MODULE(sem, sem_mod, SI_SUB_SYSV_SEM, SI_ORDER_FIRST);
|
|
MODULE_VERSION(sem, 1);
|