--- Libc/Libc-391/sys/semctl.c
+++ Libc/Libc-498/sys/semctl.c
@@ -23,38 +23,63 @@
 #include <unistd.h>
 #include <stdarg.h>
 #include <sys/sem.h>
-#include <sys/syscall.h>
+
+#if !__DARWIN_UNIX03
+#include <errno.h>
+/*
+ * Because KERNEL is defined, including errno.h doesn't define errno, so
+ * we have to do it ourselves.
+ */
+extern int * __error(void);
+#define errno (*__error())
+#endif /* !__DARWIN_UNIX03 */
 
 /*
  * Stub function to account for the differences in the ipc_perm structure,
  * while maintaining binary backward compatibility.
  */
+extern int __semctl(int semid, int semnum, int cmd, void *);
+
 int
 semctl(int semid, int semnum, int cmd, ...)
 {
-#ifdef __DARWIN_UNIX03
 	va_list			ap;
+	int			rv;
+	int			val = 0;
+#if __DARWIN_UNIX03
 	struct __semid_ds_new	*ds;
 
 	va_start(ap, cmd);
-	ds = va_arg(ap, struct __semid_ds_new *);
+	if (cmd == SETVAL) {
+		val = va_arg(ap, int);
+		rv = __semctl(semid, semnum, cmd, (void *)val);
+	} else {
+		ds = va_arg(ap, struct __semid_ds_new *);
+		rv = __semctl(semid, semnum, cmd, (void *)ds);
+	}
 	va_end(ap);
 
-	return syscall(SYS_semctl, semid, semnum, cmd, ds);
+	return rv;
 #else	/* !__DARWIN_UNIX03 */
-	va_list			ap;
-	struct __semid_ds_old	*ds_old;
 	struct __semid_ds_new	ds;
 	struct __semid_ds_new	*ds_new = &ds;
-	int			rv;
+	struct __semid_ds_old   *ds_old = NULL;
 
 	va_start(ap, cmd);
-	ds_old = va_arg(ap, struct __semid_ds_old *);
+	if (cmd == SETVAL)
+		val = va_arg(ap, int);
+	else
+		ds_old = va_arg(ap, struct __semid_ds_old *);
 	va_end(ap);
 
 #define	_UP_CVT(x)	ds_new-> x = ds_old-> x
 #define	_DN_CVT(x)	ds_old-> x = ds_new-> x
 
+	if ((cmd == IPC_SET || cmd == IPC_STAT) && ds_old == NULL) {
+		/* Return EFAULT if ds_old is NULL (like the kernel would do) */
+		errno = EFAULT;
+		return -1;
+	}
 	if (cmd == IPC_SET) {
 		/* convert before call */
 		_UP_CVT(sem_perm.uid);
@@ -75,8 +100,19 @@
 		_UP_CVT(sem_pad3[2]);	/* binary compatibility */
 		_UP_CVT(sem_pad3[3]);	/* binary compatibility */
 	}
-
-	rv = syscall(SYS_semctl, semid, semnum, cmd, &ds);
+	switch (cmd) {
+	case SETVAL:
+		/* syscall must use LP64 quantities */
+		rv = __semctl(semid, semnum, cmd, (void *)val);
+		break;
+	case IPC_SET:
+	case IPC_STAT:
+		rv = __semctl(semid, semnum, cmd, ds_new);
+		break;
+	default:
+		rv = __semctl(semid, semnum, cmd, ds_old);
+		break;
+	}
 
 	if (cmd == IPC_STAT) {
 		/* convert after call */
@@ -85,8 +121,8 @@
 		_DN_CVT(sem_perm.cuid);	/* warning!  precision loss! */
 		_DN_CVT(sem_perm.cgid);	/* warning!  precision loss! */
 		_DN_CVT(sem_perm.mode);
-		ds_new->sem_perm.seq = ds_old->sem_perm._seq;
-		ds_new->sem_perm.key = ds_old->sem_perm._key;
+		ds_old->sem_perm.seq = ds_new->sem_perm._seq;
+		ds_old->sem_perm.key = ds_new->sem_perm._key;
 		_DN_CVT(sem_base);
 		_DN_CVT(sem_nsems);
 		_DN_CVT(sem_otime);