Re: [PATCH 3/3] y2038: linux: Provide __utime64 implementation

[Adhemerval Zanella <adhemerval dot zanella at linaro dot org>]

On 07/02/2020 10:00, Lukasz Majewski wrote:
> This patch replaces auto generated wrapper (as described in
> sysdeps/unix/sysv/linux/syscalls.list) for utime with one which adds extra
> support for setting file's access and modification 64 bit time on machines
> with __TIMESIZE != 64.
> 
> Internally, the __utimensat_time64 helper function is used. This patch is
> necessary for having architectures with __WORDSIZE == 32 && __TIMESIZE != 64
> Y2038 safe.
> 
> Moreover, a 32 bit version - __utime has been refactored to internally use
> __utime64.
> The __utime is now supposed to be used on systems still supporting 32
> bit time (__TIMESIZE != 64) - hence the necessary conversion between struct
> utimbuf and struct __utimbuf64.
> 
> Build tests:
> ./src/scripts/build-many-glibcs.py glibcs
> 
> Run-time tests:
> - Run specific tests on ARM/x86 32bit systems (qemu):
>   https://github.com/lmajewski/meta-y2038 and run tests:
>   https://github.com/lmajewski/y2038-tests/commits/master
> 
> Above tests were performed with Y2038 redirection applied as well as
> without to test proper usage of both __utime64 and __utime.

LGTM with some smalls changes below.

Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>

> ---
>  include/time.h                        |  3 ++
>  sysdeps/unix/sysv/linux/syscalls.list |  1 -
>  sysdeps/unix/sysv/linux/utime.c       | 56 +++++++++++++++++++++++++++
>  3 files changed, 59 insertions(+), 1 deletion(-)
>  create mode 100644 sysdeps/unix/sysv/linux/utime.c
> 
> diff --git a/include/time.h b/include/time.h
> index b04747889a..c0d1ea3315 100644
> --- a/include/time.h
> +++ b/include/time.h
> @@ -211,9 +211,12 @@ libc_hidden_proto (__clock_getres64);
>  #endif
>  
>  #if __TIMESIZE == 64
> +# define __utime64 __utime
>  # define __utimes64 __utimes
>  # define __utimensat64 __utimensat
>  #else
> +extern int __utime64 (const char *file, const struct __utimbuf64 *times);
> +libc_hidden_proto (__utime64)
>  extern int __utimes64 (const char *file, const struct __timeval64 tvp[2]);
>  libc_hidden_proto (__utimes64)
>  extern int __utimensat64 (int fd, const char *file,

Ok.

> diff --git a/sysdeps/unix/sysv/linux/syscalls.list b/sysdeps/unix/sysv/linux/syscalls.list
> index 5d65ed23e0..e40f993495 100644
> --- a/sysdeps/unix/sysv/linux/syscalls.list
> +++ b/sysdeps/unix/sysv/linux/syscalls.list
> @@ -65,7 +65,6 @@ swapon		-	swapon		i:si	__swapon	swapon
>  swapoff		-	swapoff		i:s	__swapoff	swapoff
>  unshare		EXTRA	unshare		i:i	unshare
>  uselib		EXTRA	uselib		i:s	__compat_uselib	uselib@GLIBC_2.0:GLIBC_2.23
> -utime		-	utime		i:sP	utime
>  
>  chown		-	chown		i:sii	__libc_chown	__chown chown
>  

Ok.

> diff --git a/sysdeps/unix/sysv/linux/utime.c b/sysdeps/unix/sysv/linux/utime.c
> new file mode 100644
> index 0000000000..75ee0745ec
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/utime.c
> @@ -0,0 +1,56 @@
> +/* utime -- Change access and modification times of file.  Linux version.
> +   Copyright (C) 1991-2020 Free Software Foundation, Inc.

I think it should be only 2020, since it is a new implementation.

> +   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 <utime.h>
> +#include <time.h>
> +
> +int
> +__utime64 (const char *file, const struct __utimbuf64 *times)
> +{
> +  struct __timespec64 ts64[2];
> +
> +  if (times)

No implicit checks.

> +    {
> +      ts64[0].tv_sec = times->actime;
> +      ts64[0].tv_nsec = 0LL;
> +      ts64[1].tv_sec = times->modtime;
> +      ts64[1].tv_nsec = 0LL;
> +    }

Should we use type modifiers here?

> +
> +  return __utimensat64_helper (0, file, times ? ts64 : NULL, 0);
> +}

Ok.

> +
> +#if __TIMESIZE != 64
> +libc_hidden_def (__utime64)
> +
> +int
> +__utime (const char *file, const struct utimbuf *times)
> +{
> +  struct __utimbuf64 utb64;
> +
> +  if (times)

No implicit checks.

> +    {
> +      utb64.actime = (__time64_t) times->actime;
> +      utb64.modtime = (__time64_t) times->modtime;

Do we need to explicit cast here?

> +    }
> +
> +  return __utime64 (file, times ? &utb64 : NULL);
> +}
> +#endif
> +strong_alias (__utime, utime)
> +libc_hidden_def (utime)
> 

Ok.