Consolidate Linux select implementation

This patch consolidates the select Linux syscall implementation on
sysdeps/unix/sysv/linux/select.c.  The changes are:

  1. Remove select from auto-generation syscalls.list on the architecture
     that uses __NR_select.
  2. Remove generic implementation add a default one that handle all
     current cases (with the expection of alpha)
     The new default implementation will either use __NR_select if
     available of fallback to __NR_pselect6 otherwise.
  3. Add a alpha outlier implementation which requires old compatibility
     symbols.

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

	* sysdeps/unix/sysv/linux/alpha/Makefile (sysdep_routines): Add
	osf_select.
	* sysdeps/unix/sysv/linux/alpha/select.c: New file.
	* sysdeps/unix/sysv/linux/alpha/syscalls.list: Remove select and
	osf_select from auto-generation list.
	* sysdeps/unix/sysv/linux/syscalls.list: Likewise.
	* sysdeps/unix/sysv/linux/sparc/sparc64/syscalls.list: Likewise.
	* sysdeps/unix/sysv/linux/generic/select.c: Remove file.
	* sysdeps/unix/sysv/linux/select.c: New file.

1 files changed, 71 insertions, 0 deletions

diff --git a/sysdeps/unix/sysv/linux/select.c b/sysdeps/unix/sysv/linux/select.c
new file mode 100644
index 0000000000..be4a456a51
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/select.c
@@ -0,0 +1,71 @@
+/* Linux select 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 <sys/time.h>
+#include <sys/types.h>
+#include <sys/select.h>
+#include <errno.h>
+#include <sysdep-cancel.h>
+
+/* Check the first NFDS descriptors each in READFDS (if not NULL) for read
+   readiness, in WRITEFDS (if not NULL) for write readiness, and in EXCEPTFDS
+   (if not NULL) for exceptional conditions.  If TIMEOUT is not NULL, time out
+   after waiting the interval specified therein.  Returns the number of ready
+   descriptors, or -1 for errors.  */
+
+#ifdef __NR__newselect
+# undef __NR_select
+# define __NR_select __NR__newselect
+#endif
+
+int
+__select (int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
+	  struct timeval *timeout)
+{
+#ifdef __NR_select
+  return SYSCALL_CANCEL (select, nfds, readfds, writefds, exceptfds,
+			 timeout);
+#else
+  int result;
+  struct timespec ts, *tsp = NULL;
+
+  if (timeout)
+    {
+      TIMEVAL_TO_TIMESPEC (timeout, &ts);
+      tsp = &ts;
+    }
+
+  result = SYSCALL_CANCEL (pselect6, nfds, readfds, writefds, exceptfds, tsp,
+			   NULL);
+
+  if (timeout)
+    {
+      /* Linux by default will update the timeout after a pselect6 syscall
+         (though the pselect() glibc call suppresses this behavior).
+         Since select() on Linux has the same behavior as the pselect6
+         syscall, we update the timeout here.  */
+      TIMESPEC_TO_TIMEVAL (timeout, &ts);
+    }
+
+  return result;
+#endif
+}
+libc_hidden_def (__select)
+
+weak_alias (__select, select)
+weak_alias (__select, __libc_select)