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, 30 insertions, 0 deletions

diff --git a/sysdeps/unix/sysv/linux/statx_cp.c b/sysdeps/unix/sysv/linux/statx_cp.c
index cc6e17929e..8ed74feca5 100644
--- a/sysdeps/unix/sysv/linux/statx_cp.c
+++ b/sysdeps/unix/sysv/linux/statx_cp.c
@@ -47,3 +47,33 @@ __cp_stat64_statx (struct stat64 *to, struct statx *from)
   to->st_blksize = from->stx_blksize;
 }
 #endif
+
+#if (__WORDSIZE == 32 \
+     && (!defined __SYSCALL_WORDSIZE || __SYSCALL_WORDSIZE == 32))
+void
+__cp_stat64_t64_statx (struct __stat64_t64 *to, const struct statx *from)
+{
+  /* Clear both pad and reserved fields.  */
+  memset (to, 0, sizeof (*to));
+
+  to->st_dev = ((from->stx_dev_minor & 0xff) | (from->stx_dev_major << 8)
+		| ((from->stx_dev_minor & ~0xff) << 12));
+  to->st_ino = from->stx_ino;
+  to->st_mode = from->stx_mode;
+  to->st_nlink = from->stx_nlink;
+  to->st_uid = from->stx_uid;
+  to->st_gid = from->stx_gid;
+  to->st_rdev = ((from->stx_rdev_minor & 0xff) | (from->stx_rdev_major << 8)
+		 | ((from->stx_rdev_minor & ~0xff) << 12));
+  to->st_size = from->stx_size;
+  to->st_blksize = from->stx_blksize;
+  to->st_blocks = from->stx_blocks;
+
+  to->st_atime = from->stx_atime.tv_sec;
+  to->st_atim.tv_nsec = from->stx_atime.tv_nsec;
+  to->st_mtime = from->stx_mtime.tv_sec;
+  to->st_mtim.tv_nsec = from->stx_mtime.tv_nsec;
+  to->st_ctime = from->stx_ctime.tv_sec;
+  to->st_ctim.tv_nsec = from->stx_ctime.tv_nsec;
+}
+#endif