linux: Add {f}stat{at} y2038 support

A new struct __stat{64}_t64 type is added with the required
__timespec64 time definition.  Only LFS is added, 64-bit time with
32-bit offsets is not supposed to be supported (no existing glibc
configuration supports such a combination).  It is done with an extra
__NR_statx call plus a conversion to the new __stat{64}_t64 type.
The statx call is done only for 32-bit time_t ABIs.

Internally some extra routines to copy from/to struct stat{64}
to struct __stat{64} used on multiple implementations (stat, fstat,
lstat, and fstatat) are added on a extra implementation
(stat_t64_cp.c).  Alse some extra routines to copy from statx to
__stat{64} is added on statx_cp.c.

Checked with a build for all affected ABIs. I also checked on x86_64,
i686, powerpc, powerpc64le, sparcv9, sparc64, s390, and s390x.

Reviewed-by: Lukasz Majewski <lukma@denx.de>

1 files changed, 25 insertions, 0 deletions

diff --git a/sysdeps/unix/sysv/linux/stat_t64_cp.h b/sysdeps/unix/sysv/linux/stat_t64_cp.h
new file mode 100644
index 0000000000..18a1b92f6d
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/stat_t64_cp.h
@@ -0,0 +1,25 @@
+/* Copy to/from struct stat with and without 64-bit time_t support.
+   Copyright (C) 2020 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
+   <https://www.gnu.org/licenses/>.  */
+
+#include <sys/stat.h>
+
+#if __TIMESIZE != 64
+extern int __cp_stat64_t64_stat64 (const struct __stat64_t64 *st64_t64,
+				   struct stat64 *st64)
+  attribute_hidden;
+#endif