Re: [PATCH v2] io: fix ftw ABI on MIPS n64

"Andreas K. Huettel" <[email protected]> Wed, 22 Jul 2026 18:29:02 +0900
Newsgroups	gmane.comp.lib.glibc.alpha
Organization	Gentoo Linux
Message-ID	<[email protected]>
Am Mittwoch, 22. Juli 2026, 04:58:36 Japanische Normalzeit schrieb Xi Ruoyao:
> 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.

OK, this solves a real problem. As such we can still add it, assuming
you get an R-B soon.

Since the patch touches non-arch-specific code, however simple, I'd then
wait with the release for a few days to allow for more testing all around.
We do have a buffer until 1/August, luckily.


> 
> 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.  No new failures were found,
> and the aliasing of ftw ftw64 is as expected.  On x86_64:
> 
> $ objdump -t libc.so.6 | grep ' ftw(64)?$' -E
> 00000000001094e0  w    F .text	000000000000000f              ftw
> 00000000001094e0  w    F .text	000000000000000f              ftw64
> 
> On mips64:
> $ objdump -t libc.so.6 | grep ' ftw(64)?$' -E
> 000000000013a908 g     F .text	0000000000000028              ftw
> 000000000013bff0  w    F .text	0000000000000028              ftw64
> 
>  io/ftw.c   | 4 ++--
>  io/ftw64.c | 3 ++-
>  2 files changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/io/ftw.c b/io/ftw.c
> index ed0eeb3904..c759701372 100644
> --- a/io/ftw.c
> +++ b/io/ftw.c
> @@ -16,9 +16,9 @@
>     License along with the GNU C Library; if not, see
>     <https://www.gnu.org/licenses/>.  */
>  
> -#include <sys/types.h>
> +#include <kernel_stat.h>
>  
> -#ifndef __OFF_T_MATCHES_OFF64_T
> +#if !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..fc36f97e7e 100644
> --- a/io/ftw64.c
> +++ b/io/ftw64.c
> @@ -31,6 +31,7 @@
>  #define ftw __rename_ftw
>  #define nftw __rename_nftw
>  
> +#include <kernel_stat.h>
>  #include <shlib-compat.h>
>  #include "ftw-common.c"
>  
> @@ -44,7 +45,7 @@ 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
> +#if 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)
> 


-- 
PD Dr. Andreas K. Hüttel
[email protected]
Gentoo Linux developer 
(council, comrel, toolchain, base-system, perl, libreoffice)
https://wiki.gentoo.org/wiki/User:Dilfridge
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