Consolidate Linux poll implementation

This patch consolidates the poll Linux syscall implementation on
sysdeps/unix/sysv/linux/poll.c.  It basically removes poll from
auto-generation list and add a default implementation that either
call __NR_poll directly (if the kernel headers defines it) or
ppoll adjusting the timeout argument (as the generic implementation).

Checked on i686-linux-gnu, x86_64-linux-gnu, x86_64-linux-gnux32,
aarch64-linux-gnu, arm-linux-gnueabihf, and powerpc64le-linux-gnu.

	* sysdeps/unix/sysv/linux/generic/poll.c: Remove file.
	* sysdeps/unix/sysv/linux/poll.c: New file.
	* sysdeps/unix/sysv/linux/syscalls.list: Remove poll from
	auto-generation list.

1 files changed, 46 insertions, 0 deletions

diff --git a/sysdeps/unix/sysv/linux/poll.c b/sysdeps/unix/sysv/linux/poll.c
new file mode 100644
index 0000000000..5a781ddf48
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/poll.c
@@ -0,0 +1,46 @@
+/* Linux poll 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 <errno.h>
+#include <sys/poll.h>
+
+#include <sysdep-cancel.h>
+#include <sys/syscall.h>
+
+int
+__poll (struct pollfd *fds, nfds_t nfds, int timeout)
+{
+#ifdef __NR_poll
+  return SYSCALL_CANCEL (poll, fds, nfds, timeout);
+#else
+  struct timespec timeout_ts;
+  struct timespec *timeout_ts_p = NULL;
+
+  if (timeout >= 0)
+    {
+      timeout_ts.tv_sec = timeout / 1000;
+      timeout_ts.tv_nsec = (timeout % 1000) * 1000000;
+      timeout_ts_p = &timeout_ts;
+    }
+
+  return SYSCALL_CANCEL (ppoll, fds, nfds, timeout_ts_p, NULL, 0);
+#endif
+}
+libc_hidden_def (__poll)
+weak_alias (__poll, poll)
+strong_alias (__poll, __libc_poll)