Upstream commit:

commit eb32b0d40308166c4d8f6330cc2958cb1e545075
Author: Andreas Schwab <schwab@suse.de>
Date:   Mon Aug 10 14:12:47 2015 +0200

    Readd O_LARGEFILE flag for openat64 (bug 18781)

diff --git a/io/test-lfs.c b/io/test-lfs.c
index 539c2a2..b6ebae4 100644
--- a/io/test-lfs.c
+++ b/io/test-lfs.c
@@ -144,7 +144,7 @@ test_ftello (void)
 int
 do_test (int argc, char *argv[])
 {
-  int ret;
+  int ret, fd2;
   struct stat64 statbuf;
 
   ret = lseek64 (fd, TWO_GB+100, SEEK_SET);
@@ -195,6 +195,25 @@ do_test (int argc, char *argv[])
     error (EXIT_FAILURE, 0, "stat reported size %lld instead of %lld.",
 	   (long long int) statbuf.st_size, (TWO_GB + 100 + 5));
 
+  fd2 = openat64 (AT_FDCWD, name, O_RDWR);
+  if (fd2 == -1)
+    {
+      if (errno == ENOSYS)
+	{
+	  /* Silently ignore this test.  */
+	  error (0, 0, "openat64 is not supported");
+	}
+      else
+	error (EXIT_FAILURE, errno, "openat64 failed to open big file");
+    }
+  else
+    {
+      ret = close (fd2);
+
+      if (ret == -1)
+	error (EXIT_FAILURE, errno, "error closing file");
+    }
+
   test_ftello ();
 
   return 0;
diff --git a/sysdeps/unix/sysv/linux/openat.c b/sysdeps/unix/sysv/linux/openat.c
index 6777123..ad8e31d 100644
--- a/sysdeps/unix/sysv/linux/openat.c
+++ b/sysdeps/unix/sysv/linux/openat.c
@@ -68,6 +68,11 @@ __OPENAT (int fd, const char *file, int oflag, ...)
       va_end (arg);
     }
 
+  /* We have to add the O_LARGEFILE flag for openat64.  */
+#ifdef MORE_OFLAGS
+  oflag |= MORE_OFLAGS;
+#endif
+
   return SYSCALL_CANCEL (openat, fd, file, oflag, mode);
 }
 libc_hidden_def (__OPENAT)