[PATCH] io: fix ftw ABI on MIPS n64

On MIPS n64 off_t is same as off64_t, but struct stat is not same as
struct stat64 (very peculiar but see the "as tempting as it..." comment
in linux/mips/kernel_stat.h).  As the ftw/ftw64 callback accepts a
pointer to a function who accepts struct stat/stat64, for MIPS n64 we
must use different implementations for ftw and ftw64.

Thus for testing if ftw64 can be aliased to ftw, we should check
XSTAT_IS_XSTAT64 instead of __OFF_T_MATCHES_OFF64_T.

This resolves the io/tst-ftw-lnk failure observed on MIPS n64.

Link: https://sourceware.org/glibc/wiki/Testing/Tests/io/tst-ftw-lnk
Signed-off-by: Xi Ruoyao <[email protected]>
---

Tested on x86_64-linux and mips64-linux.

 io/ftw.c   | 2 +-
 io/ftw64.c | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/io/ftw.c b/io/ftw.c
index ed0eeb3904..79259518f6 100644
--- a/io/ftw.c
+++ b/io/ftw.c
@@ -18,7 +18,7 @@
 
 #include <sys/types.h>
 
-#ifndef __OFF_T_MATCHES_OFF64_T
+#ifndef XSTAT_IS_XSTAT64
 # include "ftw-common.c"
 
 versioned_symbol (libc, __new_nftw, nftw, GLIBC_2_3_3);
diff --git a/io/ftw64.c b/io/ftw64.c
index d3cd14c21a..6d9e6dfe22 100644
--- a/io/ftw64.c
+++ b/io/ftw64.c
@@ -44,7 +44,7 @@ versioned_symbol (libc, __new_nftw64, nftw64, GLIBC_2_3_3);
 compat_symbol (libc, __old_nftw64, nftw64, GLIBC_2_1);
 #endif
 
-#ifdef __OFF_T_MATCHES_OFF64_T
+#ifdef XSTAT_IS_XSTAT64
 weak_alias (__ftw64, ftw)
 versioned_symbol (libc, __new_nftw64, nftw, GLIBC_2_3_3);
 # if SHLIB_COMPAT(libc, GLIBC_2_1, GLIBC_2_3_3)
-- 
2.55.0