linux: Consolidate Linux open_by_handle_at syscall

This patch consolidates the open_by_handle_at Linux syscall generation on
sysdeps/unix/sysv/linux/open_by_handle_at.c.  It basically removes it from
architectures auto-generation list.

Checked on i686-linux-gnu, x86_64-linux-gnu, x86_64-linux-gnux32,
arch64-linux-gnu, arm-linux-gnueabihf, powerpc64le-linux-gnu,
sparc64-linux-gnu, and sparcv9-linux-gnu.

	* sysdeps/unix/sysv/linux/Makefile (sysdep_routines): Add
	open_by_handle_at.
	(CFLAGS-open_by_handle_at.c): New flag.
	* sysdeps/unix/sysv/linux/open_by_handle_at.c: New file.
	* sysdeps/unix/sysv/linux/syscalls.list (open_by_handle_at): New
	file.
	* misc/Makefile (CFLAGS-open_by_handle_at.c): New rule.

3 files changed, 39 insertions, 2 deletions

diff --git a/sysdeps/unix/sysv/linux/Makefile b/sysdeps/unix/sysv/linux/Makefile
index c1f6e24775..45c05f1029 100644
--- a/sysdeps/unix/sysv/linux/Makefile
+++ b/sysdeps/unix/sysv/linux/Makefile
@@ -17,7 +17,8 @@ include $(firstword $(wildcard $(sysdirs:=/sysctl.mk)))
 sysdep_routines += clone umount umount2 readahead \
 		   setfsuid setfsgid epoll_pwait signalfd \
 		   eventfd eventfd_read eventfd_write prlimit \
-		   personality epoll_wait tee vmsplice splice
+		   personality epoll_wait tee vmsplice splice \
+		   open_by_handle_at
 
 CFLAGS-gethostid.c = -fexceptions
 CFLAGS-tee.c = -fexceptions -fasynchronous-unwind-tables
diff --git a/sysdeps/unix/sysv/linux/open_by_handle_at.c b/sysdeps/unix/sysv/linux/open_by_handle_at.c
new file mode 100644
index 0000000000..e69f041280
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/open_by_handle_at.c
@@ -0,0 +1,37 @@
+/* Obtain handle for an open file via a handle.  Linux implementation.
+   Copyright (C) 2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   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 <fcntl.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sysdep-cancel.h>
+
+int
+open_by_handle_at (int mount_fd, struct file_handle *handle, int flags)
+{
+#ifdef __NR_open_by_handle_at
+  return SYSCALL_CANCEL (open_by_handle_at, mount_fd, handle, flags);
+#else
+  __set_errno (ENOSYS);
+  return -1;
+#endif
+}
+
+#ifndef __NR_open_by_handle_at
+stub_warning (open_by_handle_at)
+#endif
diff --git a/sysdeps/unix/sysv/linux/syscalls.list b/sysdeps/unix/sysv/linux/syscalls.list
index b40825afbd..a8d1299939 100644
--- a/sysdeps/unix/sysv/linux/syscalls.list
+++ b/sysdeps/unix/sysv/linux/syscalls.list
@@ -106,7 +106,6 @@ timerfd_gettime	EXTRA	timerfd_gettime	i:ip	timerfd_gettime
 fanotify_init	EXTRA	fanotify_init	i:ii	fanotify_init
 
 name_to_handle_at EXTRA	name_to_handle_at i:isppi name_to_handle_at
-open_by_handle_at EXTRA	open_by_handle_at Ci:ipi  open_by_handle_at
 
 setns		EXTRA	setns		i:ii	setns