回复: 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17日 19:27
> 收件人: yunqiang.su@cipunited.com; libc-alpha@sourceware.org
> 抄送: aurelien@aurel32.net; jiaxun.yang@flygoat.com; macro@orcam.me.uk
> 主题: Re: 回复: [PATCH] MIPS: fix y2106 problem on N64 with statx
> 
> 
> 
> On 17/03/2021 04:25, yunqiang.su@cipunited.com wrote:
> >
> >
> >> -----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/20210311123557.3
> >> 48 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?
> 
> Even though it is not the default, non LFS interface are legacy ones.
> y2038 support, for instance, is only supported with LFS interfaces.
> 
> So it is up to you if you want to fix on fstatat.c, it should also fix the s390 issue
> with missing nanosecond support.
> 

fstatat is not recommend used by any new write code?
All new write code should use 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.
> 
> But is this really an issue for MIPS in a sense legacy programs will be affected
> in the referred timeframe? If we limit the fix for newly built binaries it
> simplifies a lot the code base.
> 
> My xstat refactor work was really to avoid the nasty profileration of
> arch-specific implementations and I think we are getting a step back by
> adding back this specific fix.
> 
> If you really want to fix on legacy compat implementation, I think it would be
> better to make in arch neutral way: 1. make xstat, lxstat, fxstat call fxstatat, 2.
> add statx on fxstatat/fxstatat64, and 3.
> convert back the struct to the _STAT_VER.
> 

I will split this patch, then.

> >
> >>> 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
> >>>
> >