/*- * 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_mac.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 static int sem_count_proc(struct proc *p); static struct ksem *sem_lookup_byname(const char *name); static int sem_create(struct thread *td, const char *name, struct ksem **ksret, mode_t mode, unsigned int value); static void sem_free(struct ksem *ksnew); static int sem_perm(struct thread *td, struct ksem *ks); static void sem_enter(struct proc *p, struct ksem *ks); static int sem_leave(struct proc *p, struct ksem *ks); static void sem_exechook(void *arg, struct proc *p, struct image_params *imgp); static void sem_exithook(void *arg, struct proc *p); static void sem_forkhook(void *arg, struct proc *p1, struct proc *p2, int flags); static int sem_hasopen(struct thread *td, struct ksem *ks); static int kern_sem_close(struct thread *td, semid_t id); static int kern_sem_post(struct thread *td, semid_t id); static int kern_sem_wait(struct thread *td, semid_t id, int tryflag, struct timespec *abstime); static int kern_sem_init(struct thread *td, int dir, unsigned int value, semid_t *idp); static int kern_sem_open(struct thread *td, int dir, const char *name, int oflag, mode_t mode, unsigned int value, semid_t *idp); static int kern_sem_unlink(struct thread *td, const char *name); #ifndef SEM_MAX #define SEM_MAX 30 #endif #define SEM_MAX_NAMELEN 14 #define SEM_TO_ID(x) ((intptr_t)(x)) #define ID_TO_SEM(x) id_to_sem(x) /* * available semaphores go here, this includes sem_init and any semaphores * created via sem_open that have not yet been unlinked. */ LIST_HEAD(, ksem) ksem_head = LIST_HEAD_INITIALIZER(&ksem_head); /* * semaphores still in use but have been sem_unlink()'d go here. */ LIST_HEAD(, ksem) ksem_deadhead = LIST_HEAD_INITIALIZER(&ksem_deadhead); static struct mtx sem_lock; static MALLOC_DEFINE(M_SEM, "sems", "semaphore data"); static int nsems = 0; SYSCTL_DECL(_p1003_1b); SYSCTL_INT(_p1003_1b, OID_AUTO, nsems, CTLFLAG_RD, &nsems, 0, ""); static eventhandler_tag sem_exit_tag, sem_exec_tag, sem_fork_tag; #ifdef SEM_DEBUG #define DP(x) printf x #else #define DP(x) #endif static __inline void sem_ref(struct ksem *ks) { mtx_assert(&sem_lock, MA_OWNED); ks->ks_ref++; DP(("sem_ref: ks = %p, ref = %d\n", ks, ks->ks_ref)); } static __inline void sem_rel(struct ksem *ks) { mtx_assert(&sem_lock, MA_OWNED); DP(("sem_rel: ks = %p, ref = %d\n", ks, ks->ks_ref - 1)); if (--ks->ks_ref == 0) sem_free(ks); } static __inline struct ksem *id_to_sem(semid_t id); static __inline struct ksem * id_to_sem(semid_t id) { struct ksem *ks; mtx_assert(&sem_lock, MA_OWNED); DP(("id_to_sem: id = %0x,%p\n", id, (struct ksem *)id)); LIST_FOREACH(ks, &ksem_head, ks_entry) { DP(("id_to_sem: ks = %p\n", ks)); if (ks == (struct ksem *)id) return (ks); } return (NULL); } static struct ksem * sem_lookup_byname(const char *name) { struct ksem *ks; mtx_assert(&sem_lock, MA_OWNED); LIST_FOREACH(ks, &ksem_head, ks_entry) if (ks->ks_name != NULL && strcmp(ks->ks_name, name) == 0) return (ks); return (NULL); } static int sem_create(struct thread *td, const char *name, struct ksem **ksret, mode_t mode, unsigned int value) { struct ksem *ret; struct proc *p; struct ucred *uc; size_t len; int error; DP(("sem_create\n")); p = td->td_proc; uc = td->td_ucred; if (value > SEM_VALUE_MAX) return (EINVAL); ret = malloc(sizeof(*ret), M_SEM, M_WAITOK | M_ZERO); if (name != NULL) { len = strlen(name); if (len > SEM_MAX_NAMELEN) { free(ret, M_SEM); return (ENAMETOOLONG); } /* name must start with a '/' but not contain one. */ if (*name != '/' || len < 2 || index(name + 1, '/') != NULL) { free(ret, M_SEM); return (EINVAL); } ret->ks_name = malloc(len + 1, M_SEM, M_WAITOK); strcpy(ret->ks_name, name); } else { ret->ks_name = NULL; } ret->ks_mode = mode; ret->ks_value = value; ret->ks_ref = 1; ret->ks_waiters = 0; ret->ks_uid = uc->cr_uid; ret->ks_gid = uc->cr_gid; ret->ks_onlist = 0; cv_init(&ret->ks_cv, "sem"); LIST_INIT(&ret->ks_users); #ifdef MAC mac_init_posix_sem(ret); mac_create_posix_sem(uc, ret); #endif if (name != NULL) sem_enter(td->td_proc, ret); *ksret = ret; mtx_lock(&sem_lock); if (nsems >= p31b_getcfg(CTL_P1003_1B_SEM_NSEMS_MAX)) { sem_leave(td->td_proc, ret); sem_free(ret); error = ENFILE; } else { nsems++; error = 0; } mtx_unlock(&sem_lock); return (error); } #ifndef _SYS_SYSPROTO_H_ struct ksem_init_args { unsigned int value; semid_t *idp; }; int ksem_init(struct thread *td, struct ksem_init_args *uap); #endif int ksem_init(struct thread *td, struct ksem_init_args *uap) { int error; error = kern_sem_init(td, UIO_USERSPACE, uap->value, uap->idp); return (error); } static int kern_sem_init(struct thread *td, int dir, unsigned int value, semid_t *idp) { struct ksem *ks; semid_t id; int error; error = sem_create(td, NULL, &ks, S_IRWXU | S_IRWXG, value); if (error) return (error); id = SEM_TO_ID(ks); if (dir == UIO_USERSPACE) { error = copyout(&id, idp, sizeof(id)); if (error) { mtx_lock(&sem_lock); sem_rel(ks); mtx_unlock(&sem_lock); return (error); } } else { *idp = id; } mtx_lock(&sem_lock); LIST_INSERT_HEAD(&ksem_head, ks, ks_entry); ks->ks_onlist = 1; mtx_unlock(&sem_lock); return (error); } #ifndef _SYS_SYSPROTO_H_ struct ksem_open_args { char *name; int oflag; mode_t mode; unsigned int value; semid_t *idp; }; int ksem_open(struct thread *td, struct ksem_open_args *uap); #endif int ksem_open(struct thread *td, struct ksem_open_args *uap) { char name[SEM_MAX_NAMELEN + 1]; size_t done; int error; error = copyinstr(uap->name, name, SEM_MAX_NAMELEN + 1, &done); if (error) return (error); DP((">>> sem_open start\n")); error = kern_sem_open(td, UIO_USERSPACE, name, uap->oflag, uap->mode, uap->value, uap->idp); DP(("<<< sem_open end\n")); return (error); } static int kern_sem_open(struct thread *td, int dir, const char *name, int oflag, mode_t mode, unsigned int value, semid_t *idp) { struct ksem *ksnew, *ks; int error; semid_t id; ksnew = NULL; mtx_lock(&sem_lock); ks = sem_lookup_byname(name); /* * If we found it but O_EXCL is set, error. */ if (ks != NULL && (oflag & O_EXCL) != 0) { mtx_unlock(&sem_lock); return (EEXIST); } /* * If we didn't find it... */ if (ks == NULL) { /* * didn't ask for creation? error. */ if ((oflag & O_CREAT) == 0) { mtx_unlock(&sem_lock); return (ENOENT); } /* * We may block during creation, so drop the lock. */ mtx_unlock(&sem_lock); error = sem_create(td, name, &ksnew, mode, value); if (error != 0) return (error); id = SEM_TO_ID(ksnew); if (dir == UIO_USERSPACE) { DP(("about to copyout! %d to %p\n", id, idp)); error = copyout(&id, idp, sizeof(id)); if (error) { mtx_lock(&sem_lock); sem_leave(td->td_proc, ksnew); sem_rel(ksnew); mtx_unlock(&sem_lock); return (error); } } else { DP(("about to set! %d to %p\n", id, idp)); *idp = id; } /* * We need to make sure we haven't lost a race while * allocating during creation. */ mtx_lock(&sem_lock); ks = sem_lookup_byname(name); if (ks != NULL) { /* we lost... */ sem_leave(td->td_proc, ksnew); sem_rel(ksnew); /* we lost and we can't loose... */ if ((oflag & O_EXCL) != 0) { mtx_unlock(&sem_lock); return (EEXIST); } } else { DP(("sem_create: about to add to list...\n")); LIST_INSERT_HEAD(&ksem_head, ksnew, ks_entry); DP(("sem_create: setting list bit...\n")); ksnew->ks_onlist = 1; DP(("sem_create: done, about to unlock...\n")); } } else { #ifdef MAC error = mac_check_posix_sem_open(td->td_ucred, ks); if (error) goto err_open; #endif /* * if we aren't the creator, then enforce permissions. */ error = sem_perm(td, ks); if (error) goto err_open; sem_ref(ks); mtx_unlock(&sem_lock); id = SEM_TO_ID(ks); if (dir == UIO_USERSPACE) { error = copyout(&id, idp, sizeof(id)); if (error) { mtx_lock(&sem_lock); sem_rel(ks); mtx_unlock(&sem_lock); return (error); } } else { *idp = id; } sem_enter(td->td_proc, ks); mtx_lock(&sem_lock); sem_rel(ks); } err_open: mtx_unlock(&sem_lock); return (error); } static int sem_perm(struct thread *td, struct ksem *ks) { struct ucred *uc; uc = td->td_ucred; DP(("sem_perm: uc(%d,%d) ks(%d,%d,%o)\n", uc->cr_uid, uc->cr_gid, ks->ks_uid, ks->ks_gid, ks->ks_mode)); if ((uc->cr_uid == ks->ks_uid && (ks->ks_mode & S_IWUSR) != 0) || (uc->cr_gid == ks->ks_gid && (ks->ks_mode & S_IWGRP) != 0) || (ks->ks_mode & S_IWOTH) != 0 || suser(td) == 0) return (0); return (EPERM); } static void sem_free(struct ksem *ks) { nsems--; if (ks->ks_onlist) LIST_REMOVE(ks, ks_entry); if (ks->ks_name != NULL) free(ks->ks_name, M_SEM); cv_destroy(&ks->ks_cv); free(ks, M_SEM); } static __inline struct kuser *sem_getuser(struct proc *p, struct ksem *ks); static __inline struct kuser * sem_getuser(struct proc *p, struct ksem *ks) { struct kuser *k; LIST_FOREACH(k, &ks->ks_users, ku_next) if (k->ku_pid == p->p_pid) return (k); return (NULL); } static int sem_hasopen(struct thread *td, struct ksem *ks) { return ((ks->ks_name == NULL && sem_perm(td, ks) == 0) || sem_getuser(td->td_proc, ks) != NULL); } static int sem_leave(struct proc *p, struct ksem *ks) { struct kuser *k; DP(("sem_leave: ks = %p\n", ks)); k = sem_getuser(p, ks); DP(("sem_leave: ks = %p, k = %p\n", ks, k)); if (k != NULL) { LIST_REMOVE(k, ku_next); sem_rel(ks); DP(("sem_leave: about to free k\n")); free(k, M_SEM); DP(("sem_leave: returning\n")); return (0); } return (EINVAL); } static void sem_enter(p, ks) struct proc *p; struct ksem *ks; { struct kuser *ku, *k; ku = malloc(sizeof(*ku), M_SEM, M_WAITOK); ku->ku_pid = p->p_pid; mtx_lock(&sem_lock); k = sem_getuser(p, ks); if (k != NULL) { mtx_unlock(&sem_lock); free(ku, M_TEMP); return; } LIST_INSERT_HEAD(&ks->ks_users, ku, ku_next); sem_ref(ks); mtx_unlock(&sem_lock); } #ifndef _SYS_SYSPROTO_H_ struct ksem_unlink_args { char *name; }; int ksem_unlink(struct thread *td, struct ksem_unlink_args *uap); #endif int ksem_unlink(struct thread *td, struct ksem_unlink_args *uap) { char name[SEM_MAX_NAMELEN + 1]; size_t done; int error; error = copyinstr(uap->name, name, SEM_MAX_NAMELEN + 1, &done); return (error ? error : kern_sem_unlink(td, name)); } static int kern_sem_unlink(struct thread *td, const char *name) { struct ksem *ks; int error; mtx_lock(&sem_lock); ks = sem_lookup_byname(name); if (ks != NULL) { #ifdef MAC error = mac_check_posix_sem_unlink(td->td_ucred, ks); if (error) { mtx_unlock(&sem_lock); return (error); } #endif error = sem_perm(td, ks); } else error = ENOENT; DP(("sem_unlink: '%s' ks = %p, error = %d\n", name, ks, error)); if (error == 0) { LIST_REMOVE(ks, ks_entry); LIST_INSERT_HEAD(&ksem_deadhead, ks, ks_entry); sem_rel(ks); } mtx_unlock(&sem_lock); return (error); } #ifndef _SYS_SYSPROTO_H_ struct ksem_close_args { semid_t id; }; int ksem_close(struct thread *td, struct ksem_close_args *uap); #endif int ksem_close(struct thread *td, struct ksem_close_args *uap) { return (kern_sem_close(td, uap->id)); } static int kern_sem_close(struct thread *td, semid_t id) { struct ksem *ks; int error; error = EINVAL; mtx_lock(&sem_lock); ks = ID_TO_SEM(id); /* this is not a valid operation for unnamed sems */ if (ks != NULL && ks->ks_name != NULL) error = sem_leave(td->td_proc, ks); mtx_unlock(&sem_lock); return (error); } #ifndef _SYS_SYSPROTO_H_ struct ksem_post_args { semid_t id; }; int ksem_post(struct thread *td, struct ksem_post_args *uap); #endif int ksem_post(struct thread *td, struct ksem_post_args *uap) { return (kern_sem_post(td, uap->id)); } static int kern_sem_post(struct thread *td, semid_t id) { struct ksem *ks; int error; mtx_lock(&sem_lock); ks = ID_TO_SEM(id); if (ks == NULL || !sem_hasopen(td, ks)) { error = EINVAL; goto err; } #ifdef MAC error = mac_check_posix_sem_post(td->td_ucred, 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; err: mtx_unlock(&sem_lock); return (error); } #ifndef _SYS_SYSPROTO_H_ struct ksem_wait_args { semid_t id; }; int ksem_wait(struct thread *td, struct ksem_wait_args *uap); #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; }; int ksem_timedwait(struct thread *td, struct ksem_timedwait_args *uap); #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; }; int ksem_trywait(struct thread *td, struct ksem_trywait_args *uap); #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 ksem *ks; int error; DP((">>> kern_sem_wait entered!\n")); mtx_lock(&sem_lock); ks = ID_TO_SEM(id); if (ks == NULL) { DP(("kern_sem_wait ks == NULL\n")); error = EINVAL; goto err; } sem_ref(ks); if (!sem_hasopen(td, ks)) { DP(("kern_sem_wait hasopen failed\n")); error = EINVAL; goto err; } #ifdef MAC error = mac_check_posix_sem_wait(td->td_ucred, 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)); if (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--; error = 0; err: if (ks != NULL) sem_rel(ks); mtx_unlock(&sem_lock); DP(("<<< kern_sem_wait leaving, error = %d\n", error)); return (error); } #ifndef _SYS_SYSPROTO_H_ struct ksem_getvalue_args { semid_t id; int *val; }; int ksem_getvalue(struct thread *td, struct ksem_getvalue_args *uap); #endif int ksem_getvalue(struct thread *td, struct ksem_getvalue_args *uap) { struct ksem *ks; int error, val; mtx_lock(&sem_lock); ks = ID_TO_SEM(uap->id); if (ks == NULL || !sem_hasopen(td, ks)) { mtx_unlock(&sem_lock); return (EINVAL); } #ifdef MAC error = mac_check_posix_sem_getvalue(td->td_ucred, ks); if (error) { mtx_unlock(&sem_lock); return (error); } #endif val = ks->ks_value; mtx_unlock(&sem_lock); error = copyout(&val, uap->val, sizeof(val)); return (error); } #ifndef _SYS_SYSPROTO_H_ struct ksem_destroy_args { semid_t id; }; int ksem_destroy(struct thread *td, struct ksem_destroy_args *uap); #endif int ksem_destroy(struct thread *td, struct ksem_destroy_args *uap) { struct ksem *ks; int error; mtx_lock(&sem_lock); ks = ID_TO_SEM(uap->id); if (ks == NULL || !sem_hasopen(td, ks) || ks->ks_name != NULL) { error = EINVAL; goto err; } #ifdef MAC error = mac_check_posix_sem_destroy(td->td_ucred, ks); if (error) goto err; #endif if (ks->ks_waiters != 0) { error = EBUSY; goto err; } sem_rel(ks); error = 0; err: mtx_unlock(&sem_lock); return (error); } /* * Count the number of kusers associated with a proc, so as to guess at how * many to allocate when forking. */ static int sem_count_proc(struct proc *p) { struct ksem *ks; struct kuser *ku; int count; mtx_assert(&sem_lock, MA_OWNED); count = 0; LIST_FOREACH(ks, &ksem_head, ks_entry) { LIST_FOREACH(ku, &ks->ks_users, ku_next) { if (ku->ku_pid == p->p_pid) count++; } } LIST_FOREACH(ks, &ksem_deadhead, ks_entry) { LIST_FOREACH(ku, &ks->ks_users, ku_next) { if (ku->ku_pid == p->p_pid) count++; } } return (count); } /* * When a process forks, the child process must gain a reference to each open * semaphore in the parent process, whether it is unlinked or not. This * requires allocating a kuser structure for each semaphore reference in the * new process. Because the set of semaphores in the parent can change while * the fork is in progress, we have to handle races -- first we attempt to * allocate enough storage to acquire references to each of the semaphores, * then we enter the semaphores and release the temporary references. */ static void sem_forkhook(void *arg, struct proc *p1, struct proc *p2, int flags) { struct ksem *ks, **sem_array; int count, i, new_count; struct kuser *ku; mtx_lock(&sem_lock); count = sem_count_proc(p1); if (count == 0) { mtx_unlock(&sem_lock); return; } race_lost: mtx_assert(&sem_lock, MA_OWNED); mtx_unlock(&sem_lock); sem_array = malloc(sizeof(struct ksem *) * count, M_TEMP, M_WAITOK); mtx_lock(&sem_lock); new_count = sem_count_proc(p1); if (count < new_count) { /* Lost race, repeat and allocate more storage. */ free(sem_array, M_TEMP); count = new_count; goto race_lost; } /* * Given an array capable of storing an adequate number of semaphore * references, now walk the list of semaphores and acquire a new * reference for any semaphore opened by p1. */ count = new_count; i = 0; LIST_FOREACH(ks, &ksem_head, ks_entry) { LIST_FOREACH(ku, &ks->ks_users, ku_next) { if (ku->ku_pid == p1->p_pid) { sem_ref(ks); sem_array[i] = ks; i++; break; } } } LIST_FOREACH(ks, &ksem_deadhead, ks_entry) { LIST_FOREACH(ku, &ks->ks_users, ku_next) { if (ku->ku_pid == p1->p_pid) { sem_ref(ks); sem_array[i] = ks; i++; break; } } } mtx_unlock(&sem_lock); KASSERT(i == count, ("sem_forkhook: i != count (%d, %d)", i, count)); /* * Now cause p2 to enter each of the referenced semaphores, then * release our temporary reference. This is pretty inefficient. * Finally, free our temporary array. */ for (i = 0; i < count; i++) { sem_enter(p2, sem_array[i]); mtx_lock(&sem_lock); sem_rel(sem_array[i]); mtx_unlock(&sem_lock); } free(sem_array, M_TEMP); } static void sem_exithook(void *arg, struct proc *p, struct image_params *imgp __unused) { sem_exechook(arg, p); } static void sem_exechook(void *arg, struct proc *p) { struct ksem *ks, *ksnext; mtx_lock(&sem_lock); ks = LIST_FIRST(&ksem_head); while (ks != NULL) { ksnext = LIST_NEXT(ks, ks_entry); sem_leave(p, ks); ks = ksnext; } ks = LIST_FIRST(&ksem_deadhead); while (ks != NULL) { ksnext = LIST_NEXT(ks, ks_entry); sem_leave(p, ks); ks = ksnext; } mtx_unlock(&sem_lock); } static int sem_modload(struct module *module, int cmd, void *arg) { int error = 0; switch (cmd) { case MOD_LOAD: mtx_init(&sem_lock, "sem", "semaphore", MTX_DEF); p31b_setcfg(CTL_P1003_1B_SEM_NSEMS_MAX, SEM_MAX); p31b_setcfg(CTL_P1003_1B_SEM_VALUE_MAX, SEM_VALUE_MAX); sem_exit_tag = EVENTHANDLER_REGISTER(process_exit, sem_exithook, NULL, EVENTHANDLER_PRI_ANY); sem_exec_tag = EVENTHANDLER_REGISTER(process_exec, sem_exithook, NULL, EVENTHANDLER_PRI_ANY); sem_fork_tag = EVENTHANDLER_REGISTER(process_fork, sem_forkhook, NULL, EVENTHANDLER_PRI_ANY); break; case MOD_UNLOAD: if (nsems != 0) { error = EOPNOTSUPP; break; } EVENTHANDLER_DEREGISTER(process_exit, sem_exit_tag); EVENTHANDLER_DEREGISTER(process_exec, sem_exec_tag); EVENTHANDLER_DEREGISTER(process_fork, sem_fork_tag); mtx_destroy(&sem_lock); break; case MOD_SHUTDOWN: break; default: error = EINVAL; break; } return (error); } static moduledata_t sem_mod = { "sem", &sem_modload, NULL }; SYSCALL_MODULE_HELPER(ksem_init); SYSCALL_MODULE_HELPER(ksem_open); SYSCALL_MODULE_HELPER(ksem_unlink); SYSCALL_MODULE_HELPER(ksem_close); SYSCALL_MODULE_HELPER(ksem_post); SYSCALL_MODULE_HELPER(ksem_wait); SYSCALL_MODULE_HELPER(ksem_timedwait); SYSCALL_MODULE_HELPER(ksem_trywait); SYSCALL_MODULE_HELPER(ksem_getvalue); SYSCALL_MODULE_HELPER(ksem_destroy); DECLARE_MODULE(sem, sem_mod, SI_SUB_SYSV_SEM, SI_ORDER_FIRST); MODULE_VERSION(sem, 1);