Restore sparc64 implementation of semctl

The sparc64 variant of the ipc syscall does not dereference the pointer
argument for the SEMCTL operation.

ChangeLog

@@ -1,3 +1,7 @@
+2015-09-17  Andreas Schwab  <schwab@suse.de>
+
+	* sysdeps/unix/sysv/linux/sparc/sparc64/semctl.c: Readd.
+
 2015-09-16  Joseph Myers  <joseph@codesourcery.com>
 
 	[BZ #18977]

sysdeps/unix/sysv/linux/sparc/sparc64/semctl.c

@@ -0,0 +1,54 @@
+/* Copyright (C) 1995-2015 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Ulrich Drepper <drepper@gnu.ai.mit.edu>, August 1995.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <errno.h>
+#include <stdarg.h>
+#include <sys/sem.h>
+#include <ipc_priv.h>
+
+#include <sysdep.h>
+#include <sys/syscall.h>
+
+/* Define a `union semun' suitable for Linux here.  */
+union semun
+{
+  int val;			/* value for SETVAL */
+  struct semid_ds *buf;		/* buffer for IPC_STAT & IPC_SET */
+  unsigned short int *array;	/* array for GETALL & SETALL */
+  struct seminfo *__buf;	/* buffer for IPC_INFO */
+};
+
+/* Return identifier for array of NSEMS semaphores associated with
+   KEY.  */
+
+int
+semctl (int semid, int semnum, int cmd, ...)
+{
+  union semun arg;
+  va_list ap;
+
+  va_start (ap, cmd);
+
+  /* Get the argument.  */
+  arg = va_arg (ap, union semun);
+
+  va_end (ap);
+
+  return INLINE_SYSCALL (ipc, 5, IPCOP_semctl, semid, semnum, cmd,
+			 arg.array);
+}