回复: [PATCH] MIPS: fix y2106 problem on N64 with statx

[<yunqiang.su@cipunited.com>]

> -----邮件原件-----
> 发件人: Adhemerval Zanella <adhemerval.zanella@linaro.org>
> 发送时间: 2021年3月12日 20:35
> 收件人: YunQiang Su <yunqiang.su@cipunited.com>;
> libc-alpha@sourceware.org
> 抄送: aurelien@aurel32.net; jiaxun.yang@flygoat.com; macro@orcam.me.uk
> 主题: Re: [PATCH] MIPS: fix y2106 problem on N64 with statx
> 
> 
> 
> On 12/03/2021 00:49, YunQiang Su wrote:
> > the stat series syscall of N64 use uint32 as its time.
> > Glibc converts it to int64 then. For example a file with timestamp -1:
> >    syscall(stat) gets 0xffffffff
> >    Glibc convert it to 0x00000000ffffffff Then, -1 becomes a time in
> > y2106.
> 
> Sigh, another MIPS ABI idissionacracy that I am not aware about...
> 
> >
> > In this patch, we use statx syscall to replace stat-series syscall.
> > statx always return int64 timestamp, and the `struct stat' in userland
> > of N64 always has 64bit timestamp. We can convert between them without
> > any problem
> Some comments below.
> 
> > ---
> >  io/tst-fstatat.c                              | 26 +++++++-
> >  sysdeps/unix/sysv/linux/fstatat64.c           |  8 ++-
> >  .../unix/sysv/linux/mips/mips64/n64/fstatat.c | 52 +++++++++++++++
> > .../unix/sysv/linux/mips/mips64/n64/fxstat.c  | 51 +++++++++++++++
> >  .../sysv/linux/mips/mips64/n64/fxstat64.c     | 43 +++++++++++++
> >  .../sysv/linux/mips/mips64/n64/fxstatat.c     | 63
> +++++++++++++++++++
> >  .../sysv/linux/mips/mips64/n64/fxstatat64.c   | 53 ++++++++++++++++
> >  .../unix/sysv/linux/mips/mips64/n64/lxstat.c  | 51 +++++++++++++++
> >  .../sysv/linux/mips/mips64/n64/lxstat64.c     | 43 +++++++++++++
> >  .../unix/sysv/linux/mips/mips64/n64/xstat.c   | 51 +++++++++++++++
> >  .../unix/sysv/linux/mips/mips64/n64/xstat64.c | 43 +++++++++++++
> >  11 files changed, 482 insertions(+), 2 deletions(-)  create mode
> > 100644 sysdeps/unix/sysv/linux/mips/mips64/n64/fstatat.c
> >  create mode 100644 sysdeps/unix/sysv/linux/mips/mips64/n64/fxstat.c
> >  create mode 100644
> sysdeps/unix/sysv/linux/mips/mips64/n64/fxstat64.c
> >  create mode 100644 sysdeps/unix/sysv/linux/mips/mips64/n64/fxstatat.c
> >  create mode 100644
> > sysdeps/unix/sysv/linux/mips/mips64/n64/fxstatat64.c
> >  create mode 100644 sysdeps/unix/sysv/linux/mips/mips64/n64/lxstat.c
> >  create mode 100644
> sysdeps/unix/sysv/linux/mips/mips64/n64/lxstat64.c
> >  create mode 100644 sysdeps/unix/sysv/linux/mips/mips64/n64/xstat.c
> >  create mode 100644 sysdeps/unix/sysv/linux/mips/mips64/n64/xstat64.c
> >
> > diff --git a/io/tst-fstatat.c b/io/tst-fstatat.c index
> > 4766bb2e71..8297b14479 100644
> > --- a/io/tst-fstatat.c
> > +++ b/io/tst-fstatat.c
> > @@ -5,7 +5,7 @@
> >  #include <string.h>
> >  #include <unistd.h>
> >  #include <sys/stat.h>
> > -
> > +#include <kernel-features.h>
> >
> >  static void prepare (void);
> >  #define PREPARE(argc, argv) prepare () @@ -134,6 +134,30 @@ do_test
> > (void)
> >        puts ("stat results do not match");
> >        return 1;
> >      }
> > +#if defined(__mips64) &&  (_MIPS_SIM == _ABI64) &&
> > +defined(__ASSUME_STATX)
> > +  /* fstatat syscall has y2106 problem on MIPS N64
> > +     Now we use statx to implement *stat* functions
> > +     So the problem should have gone */
> > +  struct timespec tm_1[2] = {{-1, 0}, {-1, 0}};
> > +  if (utimensat(dir_fd, "some-file", tm_1, 0) != 0)
> > +    {
> > +      puts ("utimensat fail");
> > +      return 1;
> > +    }
> > +
> > +  if (fstatat64 (dir_fd, "some-file", &st2, 0) != 0)
> > +    {
> > +      puts ("fstatat64 failed");
> > +      return 1;
> > +    }
> > +
> > +  if (st2.st_mtim.tv_sec != -1
> > +      || st2.st_atim.tv_sec != -1)
> > +    {
> > +      puts ("fstatat64 has y2106 problem?");
> > +      return 1;
> > +    }
> > +#endif
> >
> >    if (unlinkat (dir_fd, "some-file", 0) != 0)
> >      {
> 
> I am about to push a way to check in if the file has support for y2038 [1], so
> please use this instead.  Also this tests does not really check any file
> timestamps so I don't think this is the place add this warning (and making it
> mips specific it not a good approach, neither by using __ASSUME_STATX
> which is Linux specific and it should be used on internal tests).
> 
> Instead please add the y2106 checks on Linux specific tests:
> 
>   sysdeps/unix/sysv/linux/tst-futimens.c
>   sysdeps/unix/sysv/linux/tst-utime.c
>   sysdeps/unix/sysv/linux/tst-utimes.c
> 
> Since they use fstat to check against the set timestamps.
> 
> [1]
> https://patchwork.sourceware.org/project/glibc/patch/20210311123557.348
> 6677-1-adhemerval.zanella@linaro.org/
> 

That's a great idea to add the test here.

> > diff --git a/sysdeps/unix/sysv/linux/fstatat64.c
> > b/sysdeps/unix/sysv/linux/fstatat64.c
> > index 490226a8ec..220321be9c 100644
> > --- a/sysdeps/unix/sysv/linux/fstatat64.c
> > +++ b/sysdeps/unix/sysv/linux/fstatat64.c
> > @@ -47,15 +47,21 @@ __fstatat64_time64 (int fd, const char *file, struct
> __stat64_t64 *buf,
> >    int r;
> >
> >  #if (__WORDSIZE == 32 \
> > -     && (!defined __SYSCALL_WORDSIZE || __SYSCALL_WORDSIZE ==
> 32))
> > +     && (!defined __SYSCALL_WORDSIZE || __SYSCALL_WORDSIZE ==
> 32)) \
> > +    || defined(__mips64)
> 
> I would prefer to add a define added on kernel_stat.h, even though it seems
> from a briefly inspecting on kernel sources that it is only mips64 that has this
> issue.  I think we should avoid the preprocessor archirecture define on Linux
> generic code.
> 
> So add a STAT_KERNEL_UNSIGNED_TIME_T with a proper comment on
> mips.h kernel_stat.h
> 

Yes. It is much cleaner.

> >    /* 32-bit kABI with default 64-bit time_t, e.g. arc, riscv32.   Also
> >       64-bit time_t support is done through statx syscall.  */
> > +  /* Also use statx syscall for MIPS N64, since newfstatat has y2106
> > + problem */
> >    struct statx tmp;
> 
> Merge it with the previous comment.
> 
> >    r = INTERNAL_SYSCALL_CALL (statx, fd, file, AT_NO_AUTOMOUNT |
> flag,
> >  			     STATX_BASIC_STATS, &tmp);
> >    if (r == 0)
> >      {
> > +#if defined(__mips64) && (_MIPS_SIM == _ABI64)
> > +      __cp_stat64_statx (buf, &tmp);
> > +#else
> >        __cp_stat64_t64_statx (buf, &tmp);
> > +#endif
> >        return 0;
> >      }
> >    if (-r != ENOSYS)
> > diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n64/fstatat.c
> > b/sysdeps/unix/sysv/linux/mips/mips64/n64/fstatat.c
> > new file mode 100644
> > index 0000000000..5000cd0715
> > --- /dev/null
> > +++ b/sysdeps/unix/sysv/linux/mips/mips64/n64/fstatat.c
> > @@ -0,0 +1,52 @@
> > +/* Copyright (C) 2005-2020 Free Software Foundation, Inc.
> > +   This file is part of the GNU C Library.
> > +
> > +   The GNU C Library is free software; you can redistribute it and/or
> > +   modify it under the terms of the GNU Lesser General Public
> > +   License as published by the Free Software Foundation; either
> > +   version 2.1 of the License, or (at your option) any later version.
> > +
> > +   The GNU C Library is distributed in the hope that it will be useful,
> > +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> > +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
> the GNU
> > +   Lesser General Public License for more details.
> > +
> > +   You should have received a copy of the GNU Lesser General Public
> > +   License along with the GNU C Library; if not, see
> > +   <https://www.gnu.org/licenses/>.  */
> > +
> > +/* Ho hum, since fxstatat == fxstatat64 we must get rid of the
> > +   prototype or gcc will complain since they don't strictly match.
> > +*/
> > +
> > +#include <kernel-features.h>
> > +#include <sys/syscall.h>
> > +#if defined(__ASSUME_STATX) && defined(__NR_statx) #include <errno.h>
> > +#include <fcntl.h> #include <stddef.h> #include <stdio.h> #include
> > +<string.h> #include <sys/stat.h>
> > +
> > +#include <sysdep.h>
> > +#include <kernel_stat.h>
> > +#include <statx_cp.h>
> > +
> > +
> > +/* Get information about the file NAME relative to FD in ST.  */ int
> > +__fstatat (int fd, const char *file, struct stat *st, int flag) {
> > +  struct statx xbuf;
> > +  int r = INLINE_SYSCALL (statx, 5, fd, file, flag&AT_SYMLINK_NOFOLLOW,
> > +	      STATX_BASIC_STATS, &xbuf);
> > +  if (r == 0)
> > +    __cp_stat64_statx((struct stat64 *)st, &xbuf);
> > +  return r;
> > +}
> > +
> > +weak_alias (__fstatat, fstatat)
> > +
> > +#else /* __ASSUME_STATX && __NR_statx */ #include
> > +<sysdeps/unix/sysv/linux/fstatat.c>
> > +#endif
> 
> I see no point in such optimization, which adds another mips specific file.
> If glibc is still alive near 2106 most likely we would had increases the
> minimum kernel version to include __NR_statx...
> 

linux/fstatat.c has no statx call. So, should we do the similar like fstatat64?

> > diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n64/fxstat.c
> > b/sysdeps/unix/sysv/linux/mips/mips64/n64/fxstat.c
> > new file mode 100644
> > index 0000000000..acd929dfaa
> > --- /dev/null
> > +++ b/sysdeps/unix/sysv/linux/mips/mips64/n64/fxstat.c
> > @@ -0,0 +1,51 @@
> > +/* fxstat using old-style Unix stat system call.
> > +   Copyright (C) 1991-2021 Free Software Foundation, Inc.
> > +   This file is part of the GNU C Library.
> > +
> > +   The GNU C Library is free software; you can redistribute it and/or
> > +   modify it under the terms of the GNU Lesser General Public
> > +   License as published by the Free Software Foundation; either
> > +   version 2.1 of the License, or (at your option) any later version.
> > +
> > +   The GNU C Library is distributed in the hope that it will be useful,
> > +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> > +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
> the GNU
> > +   Lesser General Public License for more details.
> > +
> > +   You should have received a copy of the GNU Lesser General Public
> > +   License along with the GNU C Library; if not, see
> > +   <https://www.gnu.org/licenses/>.  */
> > +
> > +#include <kernel-features.h>
> > +#include <sys/syscall.h>
> > +#if defined(__ASSUME_STATX) && defined(__NR_statx) #include
> > +<sys/stat.h> #include <fcntl.h> #include <kernel_stat.h> #include
> > +<sysdep.h> #include <statx_cp.h>
> > +
> > +/* Get information about the file NAME in BUF.  */ int __fxstat (int
> > +vers, int fd, struct stat *buf) {
> > +  switch (vers)
> > +    {
> > +    case _STAT_VER_KERNEL:
> > +      return INLINE_SYSCALL_CALL (fstat, fd, buf);
> > +
> > +    default:
> > +      {
> > +	struct statx xbuf;
> > +	int r = INLINE_SYSCALL (statx, 5, fd, "", AT_EMPTY_PATH,
> > +		      STATX_BASIC_STATS, &xbuf);
> > +	if (r == 0)
> > +	  __cp_stat64_statx((struct stat64 *)buf, &xbuf);
> > +	return r;
> > +      }
> > +    }
> > +}
> > +
> > +#else /* __ASSUME_STATX && __NR_statx */ #include
> > +<sysdeps/unix/sysv/linux/mips/fxstat.c>
> > +#endif
> 
> As for the mips specific implementation, the __fxstat are compatibilty symbols
> and I don't want us to change their semantic.  If user really care about
> y2106 they should use the newer stat symbols.
> 

While the pre-exists binaries do use __fxstat.
With this patch, I think that we can make them work correctly with just libc upgrade.

With the previous binaries, even they use `stat' in source code, the result binaries do use __xstat.

And the problem of Y2106 is not only about Y2106, and it also has problem for Y1969.
It may make some trouble, if we set the timestamp before 1970.

> > diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n64/fxstat64.c
> > b/sysdeps/unix/sysv/linux/mips/mips64/n64/fxstat64.c
> > new file mode 100644
> > index 0000000000..a8da108347
> > --- /dev/null
> > +++ b/sysdeps/unix/sysv/linux/mips/mips64/n64/fxstat64.c
> > @@ -0,0 +1,43 @@
> > +/* fxstat64 using 64-bit MIPS fstat system call.
> > +   Copyright (C) 1997-2020 Free Software Foundation, Inc.
> > +   This file is part of the GNU C Library.
> > +
> > +   The GNU C Library is free software; you can redistribute it and/or
> > +   modify it under the terms of the GNU Lesser General Public
> > +   License as published by the Free Software Foundation; either
> > +   version 2.1 of the License, or (at your option) any later version.
> > +
> > +   The GNU C Library is distributed in the hope that it will be useful,
> > +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> > +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
> the GNU
> > +   Lesser General Public License for more details.
> > +
> > +   You should have received a copy of the GNU Lesser General Public
> > +   License along with the GNU C Library; if not, see
> > +   <https://www.gnu.org/licenses/>.  */
> > +
> > +#include <kernel-features.h>
> > +#include <sys/syscall.h>
> > +#if defined(__ASSUME_STATX) && defined(__NR_statx) #include
> > +<sys/stat.h> #include <fcntl.h> #include <kernel_stat.h> #include
> > +<sysdep.h> #include <statx_cp.h>
> > +
> > +/* Get information about the file FD in BUF.  */
> > +
> > +int
> > +__fxstat64 (int vers, int fd, struct stat64 *buf) {
> > +  struct statx xbuf;
> > +  int r = INLINE_SYSCALL (statx, 5, fd, "", AT_EMPTY_PATH,
> > +	      STATX_BASIC_STATS, &xbuf);
> > +  if (r == 0)
> > +    __cp_stat64_statx(buf, &xbuf);
> > +  return r;
> > +}
> > +
> > +#else /* __ASSUME_STATX && __NR_statx */ #include
> > +<sysdeps/unix/sysv/linux/mips/mips64/fxstat64.c>
> > +#endif
> > diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n64/fxstatat.c
> > b/sysdeps/unix/sysv/linux/mips/mips64/n64/fxstatat.c
> > new file mode 100644
> > index 0000000000..935888efe6
> > --- /dev/null
> > +++ b/sysdeps/unix/sysv/linux/mips/mips64/n64/fxstatat.c
> > @@ -0,0 +1,63 @@
> > +/* Copyright (C) 2005-2020 Free Software Foundation, Inc.
> > +   This file is part of the GNU C Library.
> > +
> > +   The GNU C Library is free software; you can redistribute it and/or
> > +   modify it under the terms of the GNU Lesser General Public
> > +   License as published by the Free Software Foundation; either
> > +   version 2.1 of the License, or (at your option) any later version.
> > +
> > +   The GNU C Library is distributed in the hope that it will be useful,
> > +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> > +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
> the GNU
> > +   Lesser General Public License for more details.
> > +
> > +   You should have received a copy of the GNU Lesser General Public
> > +   License along with the GNU C Library; if not, see
> > +   <https://www.gnu.org/licenses/>.  */
> > +
> > +/* Ho hum, since fxstatat == fxstatat64 we must get rid of the
> > +   prototype or gcc will complain since they don't strictly match.
> > +*/
> > +
> > +#include <kernel-features.h>
> > +#include <sys/syscall.h>
> > +#if defined(__ASSUME_STATX) && defined(__NR_statx) #include <errno.h>
> > +#include <fcntl.h> #include <stddef.h> #include <stdio.h> #include
> > +<string.h> #include <sys/stat.h>
> > +
> > +#include <sysdep.h>
> > +#include <kernel_stat.h>
> > +#include <statx_cp.h>
> > +
> > +
> > +/* Get information about the file NAME relative to FD in ST.  */ int
> > +__fxstatat (int vers, int fd, const char *file, struct stat *st, int
> > +flag) {
> > +  switch (vers)
> > +    {
> > +    case _STAT_VER_KERNEL:
> > +	return INLINE_SYSCALL (newfstatat, 4, fd, file, st, flag);
> > +
> > +    case _STAT_VER_LINUX:
> > +      {
> > +	struct statx xbuf;
> > +	int r = INLINE_SYSCALL (statx, 5, fd, file, flag&AT_SYMLINK_NOFOLLOW,
> > +		      STATX_BASIC_STATS, &xbuf);
> > +	if (r == 0)
> > +	  __cp_stat64_statx((struct stat64 *)st, &xbuf);
> > +	return r;
> > +      }
> > +
> > +    default:
> > +      __set_errno (EINVAL);
> > +      return -1;
> > +    }
> > +}
> > +
> > +#else /* __ASSUME_STATX && __NR_statx */ #include
> > +<sysdeps/unix/sysv/linux/mips/mips64/fxstatat.c>
> > +#endif
> > diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n64/fxstatat64.c
> > b/sysdeps/unix/sysv/linux/mips/mips64/n64/fxstatat64.c
> > new file mode 100644
> > index 0000000000..80bd0f1d09
> > --- /dev/null
> > +++ b/sysdeps/unix/sysv/linux/mips/mips64/n64/fxstatat64.c
> > @@ -0,0 +1,53 @@
> > +/* Copyright (C) 2005-2020 Free Software Foundation, Inc.
> > +   This file is part of the GNU C Library.
> > +
> > +   The GNU C Library is free software; you can redistribute it and/or
> > +   modify it under the terms of the GNU Lesser General Public
> > +   License as published by the Free Software Foundation; either
> > +   version 2.1 of the License, or (at your option) any later version.
> > +
> > +   The GNU C Library is distributed in the hope that it will be useful,
> > +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> > +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
> the GNU
> > +   Lesser General Public License for more details.
> > +
> > +   You should have received a copy of the GNU Lesser General Public
> > +   License along with the GNU C Library.  If not, see
> > +   <https://www.gnu.org/licenses/>.  */
> > +
> > +#include <kernel-features.h>
> > +#include <sys/syscall.h>
> > +#if defined(__ASSUME_STATX) && defined(__NR_statx) #include <errno.h>
> > +#include <fcntl.h> #include <stddef.h> #include <stdio.h> #include
> > +<string.h> #include <sys/stat.h> #include <kernel_stat.h>
> > +
> > +#include <sysdep.h>
> > +#include <statx_cp.h>
> > +
> > +/* Get information about the file NAME in BUF.  */
> > +
> > +int
> > +__fxstatat64 (int vers, int fd, const char *file, struct stat64 *st,
> > +int flag) {
> > +  if (__builtin_expect (vers != _STAT_VER_LINUX, 0))
> > +    {
> > +      __set_errno (EINVAL);
> > +      return -1;
> > +    }
> > +
> > +  struct statx xbuf;
> > +  int r = INLINE_SYSCALL (statx, 5, fd, file, flag&AT_SYMLINK_NOFOLLOW,
> > +	      STATX_BASIC_STATS, &xbuf);
> > +  if (r == 0)
> > +    __cp_stat64_statx(st, &xbuf);
> > +  return r;
> > +}
> > +
> > +#else /* __ASSUME_STATX && __NR_statx */ #include
> > +<sysdeps/unix/sysv/linux/mips/mips64/fxstatat64.c>
> > +#endif
> > diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n64/lxstat.c
> > b/sysdeps/unix/sysv/linux/mips/mips64/n64/lxstat.c
> > new file mode 100644
> > index 0000000000..f9c28b753b
> > --- /dev/null
> > +++ b/sysdeps/unix/sysv/linux/mips/mips64/n64/lxstat.c
> > @@ -0,0 +1,51 @@
> > +/* lxstat using old-style Unix stat system call.
> > +   Copyright (C) 1991-2021 Free Software Foundation, Inc.
> > +   This file is part of the GNU C Library.
> > +
> > +   The GNU C Library is free software; you can redistribute it and/or
> > +   modify it under the terms of the GNU Lesser General Public
> > +   License as published by the Free Software Foundation; either
> > +   version 2.1 of the License, or (at your option) any later version.
> > +
> > +   The GNU C Library is distributed in the hope that it will be useful,
> > +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> > +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
> the GNU
> > +   Lesser General Public License for more details.
> > +
> > +   You should have received a copy of the GNU Lesser General Public
> > +   License along with the GNU C Library; if not, see
> > +   <https://www.gnu.org/licenses/>.  */
> > +
> > +#include <kernel-features.h>
> > +#include <sys/syscall.h>
> > +#if defined(__ASSUME_STATX) && defined(__NR_statx) #include
> > +<sys/stat.h> #include <fcntl.h> #include <kernel_stat.h> #include
> > +<sysdep.h> #include <statx_cp.h>
> > +
> > +/* Get information about the file NAME in BUF.  */ int __lxstat (int
> > +vers, const char *name, struct stat *buf) {
> > +  switch (vers)
> > +    {
> > +    case _STAT_VER_KERNEL:
> > +      return INLINE_SYSCALL_CALL (lstat, name, buf);
> > +
> > +    default:
> > +      {
> > +	struct statx xbuf;
> > +	int r = INLINE_SYSCALL (statx, 5, AT_FDCWD, name,
> AT_SYMLINK_NOFOLLOW,
> > +			STATX_BASIC_STATS, &xbuf);
> > +	if (r == 0)
> > +	  __cp_stat64_statx((struct stat64 *)buf, &xbuf);
> > +	return r;
> > +      }
> > +    }
> > +}
> > +
> > +#else /* __ASSUME_STATX && __NR_statx */ #include
> > +<sysdeps/unix/sysv/linux/mips/lxstat.c>
> > +#endif
> > diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n64/lxstat64.c
> > b/sysdeps/unix/sysv/linux/mips/mips64/n64/lxstat64.c
> > new file mode 100644
> > index 0000000000..927c542ca7
> > --- /dev/null
> > +++ b/sysdeps/unix/sysv/linux/mips/mips64/n64/lxstat64.c
> > @@ -0,0 +1,43 @@
> > +/* lxstat64 using 64-bit MIPS lstat system call.
> > +   Copyright (C) 1997-2020 Free Software Foundation, Inc.
> > +   This file is part of the GNU C Library.
> > +
> > +   The GNU C Library is free software; you can redistribute it and/or
> > +   modify it under the terms of the GNU Lesser General Public
> > +   License as published by the Free Software Foundation; either
> > +   version 2.1 of the License, or (at your option) any later version.
> > +
> > +   The GNU C Library is distributed in the hope that it will be useful,
> > +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> > +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
> the GNU
> > +   Lesser General Public License for more details.
> > +
> > +   You should have received a copy of the GNU Lesser General Public
> > +   License along with the GNU C Library; if not, see
> > +   <https://www.gnu.org/licenses/>.  */
> > +
> > +#include <kernel-features.h>
> > +#include <sys/syscall.h>
> > +#if defined(__ASSUME_STATX) && defined(__NR_statx) #include
> > +<sys/stat.h> #include <fcntl.h> #include <kernel_stat.h> #include
> > +<sysdep.h> #include <statx_cp.h>
> > +
> > +/* Get information about the file NAME in BUF.  */ int
> > +__lxstat64 (int vers, const char *name, struct stat64 *buf) {
> > +  struct statx xbuf;
> > +  int r = INLINE_SYSCALL (statx, 5, AT_FDCWD, name,
> AT_SYMLINK_NOFOLLOW,
> > +		STATX_BASIC_STATS, &xbuf);
> > +  // cast to struct stat from struct stat64 is OK for N64.
> > +  if (r == 0)
> > +    __cp_stat64_statx(buf, &xbuf);
> > +  return r;
> > +}
> > +
> > +#else /* __ASSUME_STATX && __NR_statx */ #include
> > +<sysdeps/unix/sysv/linux/mips/mips64/lxstat64.c>
> > +#endif
> > diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n64/xstat.c
> > b/sysdeps/unix/sysv/linux/mips/mips64/n64/xstat.c
> > new file mode 100644
> > index 0000000000..6c735e5365
> > --- /dev/null
> > +++ b/sysdeps/unix/sysv/linux/mips/mips64/n64/xstat.c
> > @@ -0,0 +1,51 @@
> > +/* xstat using old-style Unix stat system call.
> > +   Copyright (C) 1991-2021 Free Software Foundation, Inc.
> > +   This file is part of the GNU C Library.
> > +
> > +   The GNU C Library is free software; you can redistribute it and/or
> > +   modify it under the terms of the GNU Lesser General Public
> > +   License as published by the Free Software Foundation; either
> > +   version 2.1 of the License, or (at your option) any later version.
> > +
> > +   The GNU C Library is distributed in the hope that it will be useful,
> > +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> > +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
> the GNU
> > +   Lesser General Public License for more details.
> > +
> > +   You should have received a copy of the GNU Lesser General Public
> > +   License along with the GNU C Library; if not, see
> > +   <https://www.gnu.org/licenses/>.  */
> > +
> > +#include <kernel-features.h>
> > +#include <sys/syscall.h>
> > +#if defined(__ASSUME_STATX) && defined(__NR_statx) #include
> > +<sys/stat.h> #include <fcntl.h> #include <kernel_stat.h> #include
> > +<sysdep.h> #include <statx_cp.h>
> > +
> > +/* Get information about the file NAME in BUF.  */ int __xstat (int
> > +vers, const char *name, struct stat *buf) {
> > +  switch (vers)
> > +    {
> > +    case _STAT_VER_KERNEL:
> > +      return INLINE_SYSCALL_CALL (stat, name, buf);
> > +
> > +    default:
> > +      {
> > +	struct statx xbuf;
> > +	int r = INLINE_SYSCALL (statx, 5, AT_FDCWD, name, 0,
> > +			STATX_BASIC_STATS, &xbuf);
> > +	if (r == 0)
> > +	  __cp_stat64_statx((struct stat64 *)buf, &xbuf);
> > +	return r;
> > +      }
> > +    }
> > +}
> > +
> > +#else /* __ASSUME_STATX && __NR_statx */ #include
> > +<sysdeps/unix/sysv/linux/mips/xstat.c>
> > +#endif
> > diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n64/xstat64.c
> > b/sysdeps/unix/sysv/linux/mips/mips64/n64/xstat64.c
> > new file mode 100644
> > index 0000000000..84db1b7a85
> > --- /dev/null
> > +++ b/sysdeps/unix/sysv/linux/mips/mips64/n64/xstat64.c
> > @@ -0,0 +1,43 @@
> > +/* xstat64 using 64-bit MIPS stat system call.
> > +   Copyright (C) 1991-2020 Free Software Foundation, Inc.
> > +   This file is part of the GNU C Library.
> > +
> > +   The GNU C Library is free software; you can redistribute it and/or
> > +   modify it under the terms of the GNU Lesser General Public
> > +   License as published by the Free Software Foundation; either
> > +   version 2.1 of the License, or (at your option) any later version.
> > +
> > +   The GNU C Library is distributed in the hope that it will be useful,
> > +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> > +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
> the GNU
> > +   Lesser General Public License for more details.
> > +
> > +   You should have received a copy of the GNU Lesser General Public
> > +   License along with the GNU C Library; if not, see
> > +   <https://www.gnu.org/licenses/>.  */
> > +
> > +#include <kernel-features.h>
> > +#include <sys/syscall.h>
> > +#if defined(__ASSUME_STATX) && defined(__NR_statx) #include
> > +<sys/stat.h> #include <fcntl.h> #include <kernel_stat.h> #include
> > +<sysdep.h> #include <statx_cp.h>
> > +
> > +/* Get information about the file NAME in BUF.  */
> > +
> > +int
> > +__xstat64 (int vers, const char *name, struct stat64 *buf) {
> > +  struct statx xbuf;
> > +  int r = INLINE_SYSCALL (statx, 5, AT_FDCWD, name, 0,
> > +		STATX_BASIC_STATS, &xbuf);
> > +  if (r == 0)
> > +    __cp_stat64_statx(buf, &xbuf);
> > +  return r;
> > +}
> > +
> > +#else /* __ASSUME_STATX && __NR_statx */ #include
> > +<sysdeps/unix/sysv/linux/mips/mips64/xstat64.c>
> > +#endif
> >