int
sys_ksem_destroy(struct thread *td, struct ksem_destroy_args *uap)
{
struct file *fp;
struct ksem *ks;
int error;
/* No capability rights required to close a semaphore. */
error = ksem_get(td, uap->id, 0, &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);
}
int
sys_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, CAP_SEM_GETVALUE, &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);
}
int
sys_ksem_post(struct thread *td, struct ksem_post_args *uap)
{
struct file *fp;
struct ksem *ks;
int error;
error = ksem_get(td, uap->id, CAP_SEM_POST, &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);
}
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);
}
int
sys_ksem_close(struct thread *td, struct ksem_close_args *uap)
{
struct ksem *ks;
struct file *fp;
int error;
/* No capability rights required to close a semaphore. */
error = ksem_get(td, uap->id, 0, &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);
}
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, CAP_SEM_WAIT, &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);
}
