/*- * Copyright (c) 2002 Alfred Perlstein * Copyright (c) 2003-2005 SPARTA, Inc. * Copyright (c) 2005 Robert N. M. Watson * All rights reserved. * * This software was developed for the FreeBSD Project in part by Network * Associates Laboratories, the Security Research Division of Network * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), * as part of the DARPA CHATS 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 __FBSDID("$FreeBSD$"); #include "opt_compat.h" #include "opt_posix.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include FEATURE(p1003_1b_semaphores, "POSIX P1003.1B semaphores support"); /* * TODO * * - Resource limits? * - Update fstat(1) * - Replace global sem_lock with mtx_pool locks? * - Add a MAC check_create() hook for creating new named semaphores. */ #ifndef SEM_MAX #define SEM_MAX 30 #endif #ifdef SEM_DEBUG #define DP(x) printf x #else #define DP(x) #endif struct ksem_mapping { char *km_path; Fnv32_t km_fnv; struct ksem *km_ksem; LIST_ENTRY(ksem_mapping) km_link; }; static MALLOC_DEFINE(M_KSEM, "ksem", "semaphore file descriptor"); static LIST_HEAD(, ksem_mapping) *ksem_dictionary; static struct sx ksem_dict_lock; static struct mtx ksem_count_lock; static struct mtx sem_lock; static u_long ksem_hash; static int ksem_dead; #define KSEM_HASH(fnv) (&ksem_dictionary[(fnv) & ksem_hash]) static int nsems = 0; SYSCTL_DECL(_p1003_1b); SYSCTL_INT(_p1003_1b, OID_AUTO, nsems, CTLFLAG_RD, &nsems, 0, "Number of active kernel POSIX semaphores"); static int kern_sem_wait(struct thread *td, semid_t id, int tryflag, struct timespec *abstime); static int ksem_access(struct ksem *ks, struct ucred *ucred); static struct ksem *ksem_alloc(struct ucred *ucred, mode_t mode, unsigned int value); static int ksem_create(struct thread *td, const char *path, semid_t *semidp, mode_t mode, unsigned int value, int flags, int compat32); static void ksem_drop(struct ksem *ks); static int ksem_get(struct thread *td, semid_t id, struct file **fpp); static struct ksem *ksem_hold(struct ksem *ks); static void ksem_insert(char *path, Fnv32_t fnv, struct ksem *ks); static struct ksem *ksem_lookup(char *path, Fnv32_t fnv); static void ksem_module_destroy(void); static int ksem_module_init(void); static int ksem_remove(char *path, Fnv32_t fnv, struct ucred *ucred); static int sem_modload(struct module *module, int cmd, void *arg); static fo_rdwr_t ksem_read; static fo_rdwr_t ksem_write; static fo_truncate_t ksem_truncate; static fo_ioctl_t ksem_ioctl; static fo_poll_t ksem_poll; static fo_kqfilter_t ksem_kqfilter; static fo_stat_t ksem_stat; static fo_close_t ksem_closef; /* File descriptor operations. */ static struct fileops ksem_ops = { .fo_read = ksem_read, .fo_write = ksem_write, .fo_truncate = ksem_truncate, .fo_ioctl = ksem_ioctl, .fo_poll = ksem_poll, .fo_kqfilter = ksem_kqfilter, .fo_stat = ksem_stat, .fo_close = ksem_closef, .fo_flags = DFLAG_PASSABLE }; FEATURE(posix_sem, "POSIX semaphores"); static int ksem_read(struct file *fp, struct uio *uio, struct ucred *active_cred, int flags, struct thread *td) { return (EOPNOTSUPP); } static int ksem_write(struct file *fp, struct uio *uio, struct ucred *active_cred, int flags, struct thread *td) { return (EOPNOTSUPP); } static int ksem_truncate(struct file *fp, off_t length, struct ucred *active_cred, struct thread *td) { return (EINVAL); } static int ksem_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred, struct thread *td) { return (EOPNOTSUPP); } static int ksem_poll(struct file *fp, int events, struct ucred *active_cred, struct thread *td) { return (EOPNOTSUPP); } static int ksem_kqfilter(struct file *fp, struct knote *kn) { return (EOPNOTSUPP); } static int ksem_stat(struct file *fp, struct stat *sb, struct ucred *active_cred, struct thread *td) { struct ksem *ks; #ifdef MAC int error; #endif ks = fp->f_data; #ifdef MAC error = mac_posixsem_check_stat(active_cred, fp->f_cred, ks); if (error) return (error); #endif /* * Attempt to return sanish values for fstat() on a semaphore * file descriptor. */ bzero(sb, sizeof(*sb)); sb->st_mode = S_IFREG | ks->ks_mode; /* XXX */ sb->st_atim = ks->ks_atime; sb->st_ctim = ks->ks_ctime; sb->st_mtim = ks->ks_mtime; sb->st_birthtim = ks->ks_birthtime; sb->st_uid = ks->ks_uid; sb->st_gid = ks->ks_gid; return (0); } static int ksem_closef(struct file *fp, struct thread *td) { struct ksem *ks; ks = fp->f_data; fp->f_data = NULL; ksem_drop(ks); return (0); } /* * ksem object management including creation and reference counting * routines. */ static struct ksem * ksem_alloc(struct ucred *ucred, mode_t mode, unsigned int value) { struct ksem *ks; mtx_lock(&ksem_count_lock); if (nsems == p31b_getcfg(CTL_P1003_1B_SEM_NSEMS_MAX) || ksem_dead) { mtx_unlock(&ksem_count_lock); return (NULL); } nsems++; mtx_unlock(&ksem_count_lock); ks = malloc(sizeof(*ks), M_KSEM, M_WAITOK | M_ZERO); ks->ks_uid = ucred->cr_uid; ks->ks_gid = ucred->cr_gid; ks->ks_mode = mode; ks->ks_value = value; cv_init(&ks->ks_cv, "ksem"); vfs_timestamp(&ks->ks_birthtime); ks->ks_atime = ks->ks_mtime = ks->ks_ctime = ks->ks_birthtime; refcount_init(&ks->ks_ref, 1); #ifdef MAC mac_posixsem_init(ks); mac_posixsem_create(ucred, ks); #endif return (ks); } static struct ksem * ksem_hold(struct ksem *ks) { refcount_acquire(&ks->ks_ref); return (ks); } static void ksem_drop(struct ksem *ks) { if (refcount_release(&ks->ks_ref)) { #ifdef MAC mac_posixsem_destroy(ks); #endif cv_destroy(&ks->ks_cv); free(ks, M_KSEM); mtx_lock(&ksem_count_lock); nsems--; mtx_unlock(&ksem_count_lock); } } /* * Determine if the credentials have sufficient permissions for read * and write access. */ static int ksem_access(struct ksem *ks, struct ucred *ucred) { int error; error = vaccess(VREG, ks->ks_mode, ks->ks_uid, ks->ks_gid, VREAD | VWRITE, ucred, NULL); if (error) error = priv_check_cred(ucred, PRIV_SEM_WRITE, 0); return (error); } /* * Dictionary management. We maintain an in-kernel dictionary to map * paths to semaphore objects. We use the FNV hash on the path to * store the mappings in a hash table. */ static struct ksem * ksem_lookup(char *path, Fnv32_t fnv) { struct ksem_mapping *map; LIST_FOREACH(map, KSEM_HASH(fnv), km_link) { if (map->km_fnv != fnv) continue; if (strcmp(map->km_path, path) == 0) return (map->km_ksem); } return (NULL); } static void ksem_insert(char *path, Fnv32_t fnv, struct ksem *ks) { struct ksem_mapping *map; map = malloc(sizeof(struct ksem_mapping), M_KSEM, M_WAITOK); map->km_path = path; map->km_fnv = fnv; map->km_ksem = ksem_hold(ks); LIST_INSERT_HEAD(KSEM_HASH(fnv), map, km_link); } static int ksem_remove(char *path, Fnv32_t fnv, struct ucred *ucred) { struct ksem_mapping *map; int error; LIST_FOREACH(map, KSEM_HASH(fnv), km_link) { if (map->km_fnv != fnv) continue; if (strcmp(map->km_path, path) == 0) { #ifdef MAC error = mac_posixsem_check_unlink(ucred, map->km_ksem); if (error) return (error); #endif error = ksem_access(map->km_ksem, ucred); if (error) return (error); LIST_REMOVE(map, km_link); ksem_drop(map->km_ksem); free(map->km_path, M_KSEM); free(map, M_KSEM); return (0); } } return (ENOENT); } static int ksem_create_copyout_semid(struct thread *td, semid_t *semidp, int fd, int compat32) { semid_t semid; #ifdef COMPAT_FREEBSD32 int32_t semid32; #endif void *ptr; size_t ptrs; #ifdef COMPAT_FREEBSD32 if (compat32) { semid32 = fd; ptr = &semid32; ptrs = sizeof(semid32); } else { #endif semid = fd; ptr = &semid; ptrs = sizeof(semid); compat32 = 0; /* silence gcc */ #ifdef COMPAT_FREEBSD32 } #endif return (copyout(ptr, semidp, ptrs)); } /* Other helper routines. */ static int ksem_create(struct thread *td, const char *name, semid_t *semidp, mode_t mode, unsigned int value, int flags, int compat32) { struct filedesc *fdp; struct ksem *ks; struct file *fp; char *path; Fnv32_t fnv; int error, fd; if (value > SEM_VALUE_MAX) return (EINVAL); fdp = td->td_proc->p_fd; mode = (mode & ~fdp->fd_cmask) & ACCESSPERMS; error = falloc(td, &fp, &fd); if (error) { if (name == NULL) error = ENOSPC; return (error); } /* * Go ahead and copyout the file descriptor now. This is a bit * premature, but it is a lot easier to handle errors as opposed * to later when we've possibly created a new semaphore, etc. */ error = ksem_create_copyout_semid(td, semidp, fd, compat32); if (error) { fdclose(fdp, fp, fd, td); fdrop(fp, td); return (error); } if (name == NULL) { /* Create an anonymous semaphore. */ ks = ksem_alloc(td->td_ucred, mode, value); if (ks == NULL) error = ENOSPC; else ks->ks_flags |= KS_ANONYMOUS; } else { path = malloc(MAXPATHLEN, M_KSEM, M_WAITOK); error = copyinstr(name, path, MAXPATHLEN, NULL); /* Require paths to start with a '/' character. */ if (error == 0 && path[0] != '/') error = EINVAL; if (error) { fdclose(fdp, fp, fd, td); fdrop(fp, td); free(path, M_KSEM); return (error); } fnv = fnv_32_str(path, FNV1_32_INIT); sx_xlock(&ksem_dict_lock); ks = ksem_lookup(path, fnv); if (ks == NULL) { /* Object does not exist, create it if requested. */ if (flags & O_CREAT) { ks = ksem_alloc(td->td_ucred, mode, value); if (ks == NULL) error = ENFILE; else { ksem_insert(path, fnv, ks); path = NULL; } } else error = ENOENT; } else { /* * Object already exists, obtain a new * reference if requested and permitted. */ if ((flags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL)) error = EEXIST; else { #ifdef MAC error = mac_posixsem_check_open(td->td_ucred, ks); if (error == 0) #endif error = ksem_access(ks, td->td_ucred); } if (error == 0) ksem_hold(ks); #ifdef INVARIANTS else ks = NULL; #endif } sx_xunlock(&ksem_dict_lock); if (path) free(path, M_KSEM); } if (error) { KASSERT(ks == NULL, ("ksem_create error with a ksem")); fdclose(fdp, fp, fd, td); fdrop(fp, td); return (error); } KASSERT(ks != NULL, ("ksem_create w/o a ksem")); finit(fp, FREAD | FWRITE, DTYPE_SEM, ks, &ksem_ops); FILEDESC_XLOCK(fdp); if (fdp->fd_ofiles[fd] == fp) fdp->fd_ofileflags[fd] |= UF_EXCLOSE; FILEDESC_XUNLOCK(fdp); fdrop(fp, td); return (0); } static int ksem_get(struct thread *td, semid_t id, struct file **fpp) { struct ksem *ks; struct file *fp; int error; error = fget(td, id, &fp); if (error) return (EINVAL); if (fp->f_type != DTYPE_SEM) { fdrop(fp, td); return (EINVAL); } ks = fp->f_data; if (ks->ks_flags & KS_DEAD) { fdrop(fp, td); return (EINVAL); } *fpp = fp; return (0); } /* 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, 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, 0)); } #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); } static struct syscall_helper_data ksem_syscalls[] = { SYSCALL_INIT_HELPER(ksem_init), SYSCALL_INIT_HELPER(ksem_open), SYSCALL_INIT_HELPER(ksem_unlink), SYSCALL_INIT_HELPER(ksem_close), SYSCALL_INIT_HELPER(ksem_post), SYSCALL_INIT_HELPER(ksem_wait), SYSCALL_INIT_HELPER(ksem_timedwait), SYSCALL_INIT_HELPER(ksem_trywait), SYSCALL_INIT_HELPER(ksem_getvalue), SYSCALL_INIT_HELPER(ksem_destroy), SYSCALL_INIT_LAST }; #ifdef COMPAT_FREEBSD32 #include #include #include #include #include int freebsd32_ksem_init(struct thread *td, struct freebsd32_ksem_init_args *uap) { return (ksem_create(td, NULL, uap->idp, S_IRWXU | S_IRWXG, uap->value, 0, 1)); } int freebsd32_ksem_open(struct thread *td, struct freebsd32_ksem_open_args *uap) { if ((uap->oflag & ~(O_CREAT | O_EXCL)) != 0) return (EINVAL); return (ksem_create(td, uap->name, uap->idp, uap->mode, uap->value, uap->oflag, 1)); } int freebsd32_ksem_timedwait(struct thread *td, struct freebsd32_ksem_timedwait_args *uap) { struct timespec32 abstime32; struct timespec *ts, abstime; int error; /* * We allow a null timespec (wait forever). */ if (uap->abstime == NULL) ts = NULL; else { error = copyin(uap->abstime, &abstime32, sizeof(abstime32)); if (error != 0) return (error); CP(abstime32, abstime, tv_sec); CP(abstime32, abstime, tv_nsec); if (abstime.tv_nsec >= 1000000000 || abstime.tv_nsec < 0) return (EINVAL); ts = &abstime; } return (kern_sem_wait(td, uap->id, 0, ts)); } static struct syscall_helper_data ksem32_syscalls[] = { SYSCALL32_INIT_HELPER(freebsd32_ksem_init), SYSCALL32_INIT_HELPER(freebsd32_ksem_open), SYSCALL32_INIT_HELPER(ksem_unlink), SYSCALL32_INIT_HELPER(ksem_close), SYSCALL32_INIT_HELPER(ksem_post), SYSCALL32_INIT_HELPER(ksem_wait), SYSCALL32_INIT_HELPER(freebsd32_ksem_timedwait), SYSCALL32_INIT_HELPER(ksem_trywait), SYSCALL32_INIT_HELPER(ksem_getvalue), SYSCALL32_INIT_HELPER(ksem_destroy), SYSCALL_INIT_LAST }; #endif 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_SEMAPHORES, 200112L); p31b_setcfg(CTL_P1003_1B_SEM_NSEMS_MAX, SEM_MAX); p31b_setcfg(CTL_P1003_1B_SEM_VALUE_MAX, SEM_VALUE_MAX); error = syscall_helper_register(ksem_syscalls); if (error) return (error); #ifdef COMPAT_FREEBSD32 error = syscall32_helper_register(ksem32_syscalls); if (error) return (error); #endif return (0); } static void ksem_module_destroy(void) { #ifdef COMPAT_FREEBSD32 syscall32_helper_unregister(ksem32_syscalls); #endif syscall_helper_unregister(ksem_syscalls); p31b_setcfg(CTL_P1003_1B_SEMAPHORES, 0); hashdestroy(ksem_dictionary, M_KSEM, ksem_hash); sx_destroy(&ksem_dict_lock); mtx_destroy(&ksem_count_lock); mtx_destroy(&sem_lock); p31b_unsetcfg(CTL_P1003_1B_SEM_VALUE_MAX); p31b_unsetcfg(CTL_P1003_1B_SEM_NSEMS_MAX); } 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);