* io/Makefile (routines): Add fstatat, fstatat64, fxstatat, fxstatat64,

fchownat, and unlinkat.
	(static-only-routines): Add fstatat and fstatat64.
	(tests): Add tst-unlinkat, tst-fstatat, tst-futimesat, tst-renameat,
	and tst-fchownat.
	* io/Versions [GLIBC_2.4]: Add fchownat, __fxstatat, __fxstatat64,
	and unlinkat.
	* io/fcntl.h: Define AT_FDCWD, AT_SYMLINK_NOFOLLOW, and AT_REMOVEDIR.
	* io/fstatat.c: New file.
	* io/fstatat64.c: New file.
	* io/sys/stat.h: Declare fstatat, fstatat64, __fxstatat, __fxstatat64
	and define fstatat and fstatat64 inline functions.
	* libio/stdio.h: Declare renameat.
	* misc/Makefile (routines): Add futimesat.
	* misc/Versions [GLIBC_2.4]: Add futimesat.
	* posix/unistd.h: Declare fchownat and unlinkat.
	* stdio-common/Makefile (routines): Add renameat.
	* stdio-common/Versions [GLIBC_2.4]: Add renameat.
	* sysdeps/generic/fchownat.c: New file.
	* sysdeps/generic/futimesat.c: New file.
	* sysdeps/generic/fxstatat.c: New file.
	* sysdeps/generic/fxstatat64.c: New file.
	* sysdeps/generic/renameat.c: New file.
	* sysdeps/generic/unlinkat.c: New file.
	* sysdeps/unix/sysv/linux/fchownat.c: New file.
	* sysdeps/unix/sysv/linux/futimesat.c: New file.
	* sysdeps/unix/sysv/linux/fxstatat.c: New file.
	* sysdeps/unix/sysv/linux/fxstatat64.c: New file.
	* sysdeps/unix/sysv/linux/renameat.c: New file.
	* sysdeps/unix/sysv/linux/unlinkat.c: New file.
	* sysdeps/unix/sysv/linux/alpha/fxstatat.c: New file.
	* sysdeps/unix/sysv/linux/i386/fchownat.c: New file.
	* sysdeps/unix/sysv/linux/i386/fxstatat.c: New file.
	* sysdeps/unix/sysv/linux/m68k/fchownat.c: New file.
	* sysdeps/unix/sysv/linux/m68k/fxstatat.c: New file.
	* sysdeps/unix/sysv/linux/powerpc/fchownat.c: New file.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/fxstatat.c: New file.
	* sysdeps/unix/sysv/linux/s390/s390-32/fchownat.c: New file.
	* sysdeps/unix/sysv/linux/s390/s390-32/fxstatat.c: New file.
	* sysdeps/unix/sysv/linux/sh/fchownat.c: New file.
	* sysdeps/unix/sysv/linux/sh/fxstatat.c: New file.
	* sysdeps/unix/sysv/linux/sparc/sparc32/fchownat.c: New file.
	* sysdeps/unix/sysv/linux/sparc/sparc32/fxstatat.c: New file.
	* sysdeps/unix/sysv/linux/sparc/sparc64/fxstatat.c: New file.
	* sysdeps/unix/sysv/linux/wordsize-64/fxstatat.c: New file.
	* sysdeps/unix/sysv/linux/wordsize-64/fxstatat64.c: New file.
	* time/sys/time.h: Declare futimesat.
	* include/fcntl.h: Declare __atfct_seterrno.
	* sysdeps/unix/sysv/linux/openat.c (__atfct_seterrno): New function.
	Split out from openat code and called.
	(do_test): Allow openat to fail with ENOSYS.  Handle AT_FDCWD.
	* sysdeps/generic/openat.c: Handle AT_FDCWD.
	* sysdeps/generic/openat64.c: Likewise.
	* io/tst-unlinkat.c: New file.
	* io/tst-fstatat.c: New file.
	* io/tst-futimesat.c: New file.
	* io/tst-renameat.c: New file.
	* io/tst-fchownat.c: New file.
	* io/tst-openat.c: Don't fail if openat is not implemented.

	* sysdeps/unix/sysv/linux/powerpc/chown.c: Don't provide backward
	compatibility code if new kernel is guaranteed.

	* time/sys/time.h: Add a few nonnull attributes.

sysdeps/unix/sysv/linux/s390/s390-32/fchownat.c

@@ -0,0 +1,140 @@
+/* Copyright (C) 2005 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, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <unistd.h>
+
+#include <sysdep.h>
+#include <sys/syscall.h>
+#include <shlib-compat.h>
+#include <bp-checks.h>
+
+#include <linux/posix_types.h>
+#include "kernel-features.h"
+
+/*
+  In Linux 2.1.x the chown functions have been changed.  A new function lchown
+  was introduced.  The new chown now follows symlinks - the old chown and the
+  new lchown do not follow symlinks.
+  The new lchown function has the same number as the old chown had and the
+  new chown has a new number.  When compiling with headers from Linux > 2.1.8x
+  it's impossible to run this libc with older kernels.  In these cases libc
+  has therefore to route calls to chown to the old chown function.
+*/
+
+/* Running under Linux > 2.1.80.  */
+
+#ifdef __NR_chown32
+# if __ASSUME_32BITUIDS == 0
+/* This variable is shared with all files that need to check for 32bit
+   uids.  */
+extern int __libc_missing_32bit_uids;
+# endif
+#endif /* __NR_chown32 */
+
+int
+fchownat (int fd, const char *file, uid_t owner, gid_t group, int flag)
+{
+  if (flag & ~AT_SYMLINK_NOFOLLOW)
+    {
+      __set_errno (EINVAL);
+      return -1;
+    }
+
+  char *buf = NULL;
+
+  if (fd != AT_FDCWD && file[0] != '/')
+    {
+      size_t filelen = strlen (file);
+      static const char procfd[] = "/proc/self/fd/%d/%s";
+      /* Buffer for the path name we are going to use.  It consists of
+	 - the string /proc/self/fd/
+	 - the file descriptor number
+	 - the file name provided.
+	 The final NUL is included in the sizeof.   A bit of overhead
+	 due to the format elements compensates for possible negative
+	 numbers.  */
+      size_t buflen = sizeof (procfd) + sizeof (int) * 3 + filelen;
+      buf = alloca (buflen);
+
+      __snprintf (buf, buflen, procfd, fd, file);
+      file = buf;
+    }
+
+  int result;
+  INTERNAL_SYSCALL_DECL (err);
+
+#if __ASSUME_32BITUIDS > 0
+  result = INTERNAL_SYSCALL (chown32, err, 3, CHECK_STRING (file), owner,
+			     group);
+#else
+  static int __libc_old_chown;
+
+# ifdef __NR_chown32
+  if (__libc_missing_32bit_uids <= 0)
+    {
+      if (flag & AT_SYMLINK_NOFOLLOW)
+	result = INTERNAL_SYSCALL (lchown32, err, 3, CHECK_STRING (file),
+				   owner, group);
+      else
+	result = INTERNAL_SYSCALL (chown32, err, 3, CHECK_STRING (file),
+				   owner, group);
+
+      if (__builtin_expect (!INTERNAL_SYSCALL_ERROR_P (result, err), 1))
+	return result;
+      if (INTERNAL_SYSCALL_ERRNO (result, err) != ENOSYS)
+	goto fail;
+
+      __libc_missing_32bit_uids = 1;
+    }
+# endif /* __NR_chown32 */
+  if (((owner + 1) > (uid_t) ((__kernel_uid_t) -1U))
+      || ((group + 1) > (gid_t) ((__kernel_gid_t) -1U)))
+    {
+      __set_errno (EINVAL);
+      return -1;
+    }
+
+  if (!__libc_old_chown && (flag & AT_SYMLINK_NOFOLLOW) == 0)
+    {
+      result = INTERNAL_SYSCALL (chown, err, 3, CHECK_STRING (file), owner,
+				 group);
+
+      if (!INTERNAL_SYSCALL_ERROR_P (result, err))
+	return result;
+      if (INTERNAL_SYSCALL_ERRNO (result, err) != ENOSYS)
+	goto fail;
+
+      __libc_old_chown = 1;
+    }
+
+  result = INTERNAL_SYSCALL (lchown, err, 3, CHECK_STRING (file), owner,
+			     group);
+#endif
+
+  if (__builtin_expect (INTERNAL_SYSCALL_ERROR_P (result, err), 0))
+    {
+    fail:
+      __atfct_seterrno (INTERNAL_SYSCALL_ERRNO (result, err), fd, buf);
+      result = -1;
+    }
+
+  return result;
+}

sysdeps/unix/sysv/linux/s390/s390-32/fxstatat.c

@@ -0,0 +1 @@
+#include <sysdeps/unix/sysv/linux/i386/fxstatat.c>