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

  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.
---
 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
  

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.
  

Hi Adhemerval,

> 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.

Ok.

> 
> > +   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.

Please consider my reply to __utimes64 patch.

> 
> > +    {
> > +      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?

the __utime64 has following parameters: (const char *file, const struct
__utimbuf64 *times)

Hence, the times has __time64_t actime and modtime members and casting
them to __time64_t tv.sec shall be safe.

> 
> > +
> > +  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?

We could get away with not having them (as we cast from smaller range
integer to larger one).

However, the __utime's *times parameter points to struct utimbuf, which
atime and modtime fields are __time_t (32 bit on ARM32).
I've add those casts to emphasize that we do convert to 64 bit types.

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




Best regards,

Lukasz Majewski

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