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, 72 insertions, 23 deletions

diff --git a/sysdeps/unix/sysv/linux/fstatat64.c b/sysdeps/unix/sysv/linux/fstatat64.c
index d9d3ea5e64..ae8fc101c5 100644
--- a/sysdeps/unix/sysv/linux/fstatat64.c
+++ b/sysdeps/unix/sysv/linux/fstatat64.c
@@ -19,56 +19,105 @@
 #define __fstatat __redirect___fstatat
 #define fstatat   __redirect_fstatat
 #include <sys/stat.h>
-#undef __fstatat
-#undef fstatat
 #include <fcntl.h>
-
+#include <string.h>
 #include <kernel_stat.h>
 #include <sysdep.h>
-
+#include <time.h>
 #include <statx_cp.h>
 #include <kstat_cp.h>
+#include <stat_t64_cp.h>
 
 int
-__fstatat64 (int fd, const char *file, struct stat64 *buf, int flag)
+__fstatat64_time64 (int fd, const char *file, struct __stat64_t64 *buf,
+		    int flag)
 {
+  int r;
+
+#if (__WORDSIZE == 32 \
+     && (!defined __SYSCALL_WORDSIZE || __SYSCALL_WORDSIZE == 32))
+  /* 32-bit kABI with default 64-bit time_t, e.g. arc, riscv32.   Also
+     64-bit time_t support is done through statx syscall.  */
+  struct statx tmp;
+  r = INLINE_SYSCALL_CALL (statx, fd, file, AT_NO_AUTOMOUNT | flag,
+			   STATX_BASIC_STATS, &tmp);
+  if (r == 0 || errno != ENOSYS)
+    {
+      if (r == 0)
+	__cp_stat64_t64_statx (buf, &tmp);
+      return r;
+    }
+#endif
+
 #if XSTAT_IS_XSTAT64
 # ifdef __NR_newfstatat
   /* 64-bit kABI, e.g. aarch64, ia64, powerpc64*, s390x, riscv64, and
      x86_64.  */
-  return INLINE_SYSCALL_CALL (newfstatat, fd, file, buf, flag);
+  r = INLINE_SYSCALL_CALL (newfstatat, fd, file, buf, flag);
 # elif defined __NR_fstatat64
 #  if STAT64_IS_KERNEL_STAT64
-  /* 64-bit kABI outlier, e.g. alpha.  */
-  return INLINE_SYSCALL_CALL (fstatat64, fd, file, buf, flag);
+  /* 64-bit kABI outlier, e.g. alpha  */
+  r = INLINE_SYSCALL_CALL (fstatat64, fd, file, buf, flag);
 #  else
   /* 64-bit kABI outlier, e.g. sparc64.  */
   struct kernel_stat64 kst64;
-  int r = INLINE_SYSCALL_CALL (fstatat64, fd, file, &kst64, flag);
-  return r ?: __cp_stat64_kstat64 (buf, &kst64);
-#  endif
-# else
-  /* 32-bit kABI with default 64-bit time_t, e.g. arc, riscv32.  */
-  struct statx tmp;
-  int r = INLINE_SYSCALL_CALL (statx, fd, file, AT_NO_AUTOMOUNT | flag,
-			       STATX_BASIC_STATS, &tmp);
+  r = INLINE_SYSCALL_CALL (fstatat64, fd, file, &kst64, flag);
   if (r == 0)
-    __cp_stat64_statx (buf, &tmp);
-  return r;
+    r = __cp_stat64_kstat64 (buf, &kst64);
+#  endif
 # endif
 #else
 # ifdef __NR_fstatat64
-  /* All kABIs with non-LFS support, e.g. arm, csky, i386, hppa, m68k,
-     microblaze, nios2, sh, powerpc32, and sparc32.  */
-  return INLINE_SYSCALL_CALL (fstatat64, fd, file, buf, flag);
+  /* All kABIs with non-LFS support and with old 32-bit time_t support
+     e.g. arm, csky, i386, hppa, m68k, microblaze, nios2, sh, powerpc32,
+     and sparc32.  */
+  struct stat64 st64;
+  r = INLINE_SYSCALL_CALL (fstatat64, fd, file, &st64, flag);
+  if (r == 0)
+    {
+      /* Clear both pad and reserved fields.  */
+      memset (buf, 0, sizeof (*buf));
+
+      buf->st_dev = st64.st_dev,
+      buf->st_ino = st64.st_ino;
+      buf->st_mode = st64.st_mode;
+      buf->st_nlink = st64.st_nlink;
+      buf->st_uid = st64.st_uid;
+      buf->st_gid = st64.st_gid;
+      buf->st_rdev = st64.st_rdev;
+      buf->st_size = st64.st_size;
+      buf->st_blksize = st64.st_blksize;
+      buf->st_blocks  = st64.st_blocks;
+      buf->st_atim = valid_timespec_to_timespec64 (st64.st_atim);
+      buf->st_mtim = valid_timespec_to_timespec64 (st64.st_mtim);
+      buf->st_ctim = valid_timespec_to_timespec64 (st64.st_ctim);
+    }
 # else
   /* 64-bit kabi outlier, e.g. mips64 and mips64-n32.  */
   struct kernel_stat kst;
-  int r = INLINE_SYSCALL_CALL (newfstatat, fd, file, &kst, flag);
-  return r ?: __cp_kstat_stat64 (&kst, buf);
+  r = INLINE_SYSCALL_CALL (newfstatat, fd, file, &kst, flag);
+  if (r == 0)
+    r =  __cp_kstat_stat64_t64 (&kst, buf);
 # endif
 #endif
+
+  return r;
 }
+#if __TIMESIZE != 64
+hidden_def (__fstatat64_time64)
+
+int
+__fstatat64 (int fd, const char *file, struct stat64 *buf, int flags)
+{
+  struct __stat64_t64 st_t64;
+  return __fstatat64_time64 (fd, file, &st_t64, flags)
+	 ?: __cp_stat64_t64_stat64 (&st_t64, buf);
+}
+#endif
+
+#undef __fstatat
+#undef fstatat
+
 hidden_def (__fstatat64)
 weak_alias (__fstatat64, fstatat64)