[RFC PATCH 25/52] Y2038: add function __stat64_t64 (and __xstat64_t64)

["Albert ARIBAUD (3ADEV)" <albert.aribaud@3adev.fr>]

There is no Y2038-proof linux struct stat for now, so these
implementations just use the existing syscalls and convert from kernel
32-bit-time struct stat64 to GLIBC Y2038-ready struct __stat64_t64.

Signed-off-by: Albert ARIBAUD (3ADEV) <albert.aribaud@3adev.fr>
---
 include/sys/stat.h                |  2 ++
 io/Versions                       |  1 +
 io/stat64.c                       |  7 ++++++
 sysdeps/unix/sysv/linux/xstat64.c | 50 +++++++++++++++++++++++++++++++++++++++
 4 files changed, 60 insertions(+)

diff --git a/include/sys/stat.h b/include/sys/stat.h
index 2961849e35..8cd3fbedae 100644
--- a/include/sys/stat.h
+++ b/include/sys/stat.h
@@ -39,6 +39,8 @@ extern int __mknod (const char *__path,
 		    __mode_t __mode, __dev_t __dev);
 extern int __fxstat64_t64 (int __ver, int __fildes,
                            struct __stat64_t64 *__stat_buf);
+extern int __xstat64_t64 (int __ver, const char *__filename,
+                          struct __stat64_t64 *__stat_buf);
 #if IS_IN (libc) || IS_IN (rtld)
 hidden_proto (__fxstat)
 hidden_proto (__fxstat64)
diff --git a/io/Versions b/io/Versions
index 747ae5d9d6..e2befdbdf7 100644
--- a/io/Versions
+++ b/io/Versions
@@ -131,5 +131,6 @@ libc {
 
   GLIBC_Y2038 {
     __fxstat64_t64;
+    __xstat64_t64;
   }
 }
diff --git a/io/stat64.c b/io/stat64.c
index 704cbb34a6..22fc0db13d 100644
--- a/io/stat64.c
+++ b/io/stat64.c
@@ -50,3 +50,10 @@ stat64 (const char *file, struct stat64 *buf)
 {
   return __xstat64 (_STAT_VER, file, buf);
 }
+
+int
+attribute_hidden
+__stat64_t64 (const char *file, struct __stat64_t64 *buf)
+{
+  return __xstat64_t64 (_STAT_VER, file, buf);
+}
diff --git a/sysdeps/unix/sysv/linux/xstat64.c b/sysdeps/unix/sysv/linux/xstat64.c
index b3fbe6a383..325ed36d1d 100644
--- a/sysdeps/unix/sysv/linux/xstat64.c
+++ b/sysdeps/unix/sysv/linux/xstat64.c
@@ -24,6 +24,8 @@
 #include <sysdep.h>
 #include <sys/syscall.h>
 
+#include <xstatconv.h>
+
 #include <kernel-features.h>
 
 /* Get information about the file NAME in BUF.  */
@@ -52,3 +54,51 @@ hidden_ver (___xstat64, __xstat64)
 strong_alias (___xstat64, __xstat64)
 hidden_def (__xstat64)
 #endif
+
+/* 64-bit time version */
+
+extern int __y2038_linux_support;
+
+int
+__xstat64_t64 (int vers, const char *name, struct __stat64_t64 *buf)
+{
+  int result;
+  struct stat64 st64;
+
+  if (__y2038_linux_support)
+    {
+      // TODO: use 64-bit syscalls when they become available
+    }
+
+  result = INLINE_SYSCALL (stat64, 2, name, &st64);
+#if defined _HAVE_STAT64___ST_INO && !__ASSUME_ST_INO_64_BIT
+  if (__builtin_expect (!result, 1) && st64.__st_ino != (__ino_t) st64.st_ino)
+    st64.st_ino = st64.__st_ino;
+#endif
+  if (!result)
+    {
+      buf->st_dev          = st64.st_dev;
+      buf->__pad1		     = st64.__pad1;
+    
+      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->__pad2          = st64.__pad2;
+      buf->st_size         = st64.st_size;		 
+      buf->st_blksize      = st64.st_blksize;
+    
+      buf->st_blocks       = st64.st_blocks;		
+      buf->st_atim.tv_sec  = st64.st_ctim.tv_sec;	
+      buf->st_atim.tv_nsec = st64.st_atim.tv_nsec;	
+      buf->st_mtim.tv_sec  = st64.st_mtim.tv_sec;	
+      buf->st_mtim.tv_nsec = st64.st_mtim.tv_nsec;	
+      buf->st_ctim.tv_sec  = st64.st_ctim.tv_sec;	
+      buf->st_ctim.tv_nsec = st64.st_ctim.tv_nsec;	
+    
+      buf->st_ino          = st64.st_ino;
+    }
+  return result;
+}
-- 
2.11.0