[2/3] y2038: linux: Provide __utimes64 implementation

  This patch provides new __utimes64 explicit 64 bit function for setting file's
64 bit attributes for access and modification time.

Internally, the __utimensat64_helper function is used. This patch is necessary
for having architectures with __WORDSIZE == 32 Y2038 safe.

Moreover, a 32 bit version - __utimes has been refactored to internally use
__utimes64.

The __utimes is now supposed to be used on systems still supporting 32
bit time (__TIMESIZE != 64) - hence the necessary conversion of struct
timeval to 64 bit struct __timeval64.

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 __utimes64 and __utimes.
---
 include/time.h                   |  3 +++
 sysdeps/unix/sysv/linux/utimes.c | 37 ++++++++++++++++++++++----------
 2 files changed, 29 insertions(+), 11 deletions(-)
  

On 07/02/2020 10:00, Lukasz Majewski wrote:
> This patch provides new __utimes64 explicit 64 bit function for setting file's
> 64 bit attributes for access and modification time.
> 
> Internally, the __utimensat64_helper function is used. This patch is necessary
> for having architectures with __WORDSIZE == 32 Y2038 safe.
> 
> Moreover, a 32 bit version - __utimes has been refactored to internally use
> __utimes64.
> 
> The __utimes is now supposed to be used on systems still supporting 32
> bit time (__TIMESIZE != 64) - hence the necessary conversion of struct
> timeval to 64 bit struct __timeval64.
> 
> 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 __utimes64 and __utimes.

LGTM with some smalls changes below.

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

> ---
>  include/time.h                   |  3 +++
>  sysdeps/unix/sysv/linux/utimes.c | 37 ++++++++++++++++++++++----------
>  2 files changed, 29 insertions(+), 11 deletions(-)
> 
> diff --git a/include/time.h b/include/time.h
> index e38f5e32e6..b04747889a 100644
> --- a/include/time.h
> +++ b/include/time.h
> @@ -211,8 +211,11 @@ libc_hidden_proto (__clock_getres64);
>  #endif
>  
>  #if __TIMESIZE == 64
> +# define __utimes64 __utimes
>  # define __utimensat64 __utimensat
>  #else
> +extern int __utimes64 (const char *file, const struct __timeval64 tvp[2]);
> +libc_hidden_proto (__utimes64)
>  extern int __utimensat64 (int fd, const char *file,
>                            const struct __timespec64 tsp[2], int flags);
>  libc_hidden_proto (__utimensat64);

Ok.

> diff --git a/sysdeps/unix/sysv/linux/utimes.c b/sysdeps/unix/sysv/linux/utimes.c
> index 121d883469..09c4e56f18 100644
> --- a/sysdeps/unix/sysv/linux/utimes.c
> +++ b/sysdeps/unix/sysv/linux/utimes.c
> @@ -16,22 +16,37 @@
>     License along with the GNU C Library; if not, see
>     <https://www.gnu.org/licenses/>.  */
>  
> -#include <errno.h>
> -#include <stddef.h>
> -#include <utime.h>
> -#include <sys/time.h>
> -#include <sysdep.h>
> +#include <time.h>
>  
> +int
> +__utimes64 (const char *file, const struct __timeval64 tvp[2])
> +{
> +  struct __timespec64 ts64[2];
> +
> +  if (tvp)

No implicit checks.

> +    {
> +      ts64[0] = timeval64_to_timespec64 (tvp[0]);
> +      ts64[1] = timeval64_to_timespec64 (tvp[1]);
> +    }
> +
> +  return __utimensat64_helper (0, file, tvp ? ts64 : NULL, 0);
> +}

Ok.

>  
> -/* Consider moving to syscalls.list.  */
> +#if __TIMESIZE != 64
> +libc_hidden_def (__utimes64)
>  
> -/* Change the access time of FILE to TVP[0] and
> -   the modification time of FILE to TVP[1].  */
>  int
>  __utimes (const char *file, const struct timeval tvp[2])
>  {
> -  /* Avoid implicit array coercion in syscall macros.  */
> -  return INLINE_SYSCALL (utimes, 2, file, &tvp[0]);
> -}
> +  struct __timeval64 tv64[2];
>  
> +  if (tvp)

No implicit checks.

> +    {
> +      tv64[0] = valid_timeval_to_timeval64 (tvp[0]);
> +      tv64[1] = valid_timeval_to_timeval64 (tvp[1]);
> +    }
> +
> +  return __utimes64 (file, tvp ? tv64 : NULL);
> +}
> +#endif
>  weak_alias (__utimes, utimes)
> 

Ok.
  

Hi Adhemerval,

> On 07/02/2020 10:00, Lukasz Majewski wrote:
> > This patch provides new __utimes64 explicit 64 bit function for
> > setting file's 64 bit attributes for access and modification time.
> > 
> > Internally, the __utimensat64_helper function is used. This patch
> > is necessary for having architectures with __WORDSIZE == 32 Y2038
> > safe.
> > 
> > Moreover, a 32 bit version - __utimes has been refactored to
> > internally use __utimes64.
> > 
> > The __utimes is now supposed to be used on systems still supporting
> > 32 bit time (__TIMESIZE != 64) - hence the necessary conversion of
> > struct timeval to 64 bit struct __timeval64.
> > 
> > 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 __utimes64 and __utimes.  
> 
> LGTM with some smalls changes below.
> 
> Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
> 
> > ---
> >  include/time.h                   |  3 +++
> >  sysdeps/unix/sysv/linux/utimes.c | 37
> > ++++++++++++++++++++++---------- 2 files changed, 29 insertions(+),
> > 11 deletions(-)
> > 
> > diff --git a/include/time.h b/include/time.h
> > index e38f5e32e6..b04747889a 100644
> > --- a/include/time.h
> > +++ b/include/time.h
> > @@ -211,8 +211,11 @@ libc_hidden_proto (__clock_getres64);
> >  #endif
> >  
> >  #if __TIMESIZE == 64
> > +# define __utimes64 __utimes
> >  # define __utimensat64 __utimensat
> >  #else
> > +extern int __utimes64 (const char *file, const struct __timeval64
> > tvp[2]); +libc_hidden_proto (__utimes64)
> >  extern int __utimensat64 (int fd, const char *file,
> >                            const struct __timespec64 tsp[2], int
> > flags); libc_hidden_proto (__utimensat64);  
> 
> Ok.
> 
> > diff --git a/sysdeps/unix/sysv/linux/utimes.c
> > b/sysdeps/unix/sysv/linux/utimes.c index 121d883469..09c4e56f18
> > 100644 --- a/sysdeps/unix/sysv/linux/utimes.c
> > +++ b/sysdeps/unix/sysv/linux/utimes.c
> > @@ -16,22 +16,37 @@
> >     License along with the GNU C Library; if not, see
> >     <https://www.gnu.org/licenses/>.  */
> >  
> > -#include <errno.h>
> > -#include <stddef.h>
> > -#include <utime.h>
> > -#include <sys/time.h>
> > -#include <sysdep.h>
> > +#include <time.h>
> >  
> > +int
> > +__utimes64 (const char *file, const struct __timeval64 tvp[2])
> > +{
> > +  struct __timespec64 ts64[2];
> > +
> > +  if (tvp)  
> 
> No implicit checks.

The documentation [1] and [2] explicitly says that times (here tvp) can
be NULL:
"If times is NULL, then the access and modification times of the file
are set to the current time. "

Hence, it is perfectly valid to pass the NULL to the
__utimensat64_helper(). Without this check we will segfault earlier
(before we reach proper syscall) and introduce regression in glibc.


Links:

[1] - https://linux.die.net/man/2/utimes
[2] - https://www.unix.com/man-page/linux/2/utimes/

> 
> > +    {
> > +      ts64[0] = timeval64_to_timespec64 (tvp[0]);
> > +      ts64[1] = timeval64_to_timespec64 (tvp[1]);
> > +    }
> > +
> > +  return __utimensat64_helper (0, file, tvp ? ts64 : NULL, 0);
> > +}  
> 
> Ok.
> 
> >  
> > -/* Consider moving to syscalls.list.  */
> > +#if __TIMESIZE != 64
> > +libc_hidden_def (__utimes64)
> >  
> > -/* Change the access time of FILE to TVP[0] and
> > -   the modification time of FILE to TVP[1].  */
> >  int
> >  __utimes (const char *file, const struct timeval tvp[2])
> >  {
> > -  /* Avoid implicit array coercion in syscall macros.  */
> > -  return INLINE_SYSCALL (utimes, 2, file, &tvp[0]);
> > -}
> > +  struct __timeval64 tv64[2];
> >  
> > +  if (tvp)  
> 
> No implicit checks.

Please consider the above comment.

> 
> > +    {
> > +      tv64[0] = valid_timeval_to_timeval64 (tvp[0]);
> > +      tv64[1] = valid_timeval_to_timeval64 (tvp[1]);
> > +    }
> > +
> > +  return __utimes64 (file, tvp ? tv64 : NULL);
> > +}
> > +#endif
> >  weak_alias (__utimes, utimes)
> >   
> 
> Ok.




Best regards,

Lukasz Majewski

--

DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-59 Fax: (+49)-8142-66989-80 Email: lukma@denx.de
  

On 20/02/2020 12:23, Lukasz Majewski wrote:
> Hi Adhemerval,
> 
>> On 07/02/2020 10:00, Lukasz Majewski wrote:
>>> This patch provides new __utimes64 explicit 64 bit function for
>>> setting file's 64 bit attributes for access and modification time.
>>>
>>> Internally, the __utimensat64_helper function is used. This patch
>>> is necessary for having architectures with __WORDSIZE == 32 Y2038
>>> safe.
>>>
>>> Moreover, a 32 bit version - __utimes has been refactored to
>>> internally use __utimes64.
>>>
>>> The __utimes is now supposed to be used on systems still supporting
>>> 32 bit time (__TIMESIZE != 64) - hence the necessary conversion of
>>> struct timeval to 64 bit struct __timeval64.
>>>
>>> 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 __utimes64 and __utimes.  
>>
>> LGTM with some smalls changes below.
>>
>> Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
>>
>>> ---
>>>  include/time.h                   |  3 +++
>>>  sysdeps/unix/sysv/linux/utimes.c | 37
>>> ++++++++++++++++++++++---------- 2 files changed, 29 insertions(+),
>>> 11 deletions(-)
>>>
>>> diff --git a/include/time.h b/include/time.h
>>> index e38f5e32e6..b04747889a 100644
>>> --- a/include/time.h
>>> +++ b/include/time.h
>>> @@ -211,8 +211,11 @@ libc_hidden_proto (__clock_getres64);
>>>  #endif
>>>  
>>>  #if __TIMESIZE == 64
>>> +# define __utimes64 __utimes
>>>  # define __utimensat64 __utimensat
>>>  #else
>>> +extern int __utimes64 (const char *file, const struct __timeval64
>>> tvp[2]); +libc_hidden_proto (__utimes64)
>>>  extern int __utimensat64 (int fd, const char *file,
>>>                            const struct __timespec64 tsp[2], int
>>> flags); libc_hidden_proto (__utimensat64);  
>>
>> Ok.
>>
>>> diff --git a/sysdeps/unix/sysv/linux/utimes.c
>>> b/sysdeps/unix/sysv/linux/utimes.c index 121d883469..09c4e56f18
>>> 100644 --- a/sysdeps/unix/sysv/linux/utimes.c
>>> +++ b/sysdeps/unix/sysv/linux/utimes.c
>>> @@ -16,22 +16,37 @@
>>>     License along with the GNU C Library; if not, see
>>>     <https://www.gnu.org/licenses/>.  */
>>>  
>>> -#include <errno.h>
>>> -#include <stddef.h>
>>> -#include <utime.h>
>>> -#include <sys/time.h>
>>> -#include <sysdep.h>
>>> +#include <time.h>
>>>  
>>> +int
>>> +__utimes64 (const char *file, const struct __timeval64 tvp[2])
>>> +{
>>> +  struct __timespec64 ts64[2];
>>> +
>>> +  if (tvp)  
>>
>> No implicit checks.
> 
> The documentation [1] and [2] explicitly says that times (here tvp) can
> be NULL:
> "If times is NULL, then the access and modification times of the file
> are set to the current time. "
> 
> Hence, it is perfectly valid to pass the NULL to the
> __utimensat64_helper(). Without this check we will segfault earlier
> (before we reach proper syscall) and introduce regression in glibc.

I meant to use:

  if (tvp != NULL)
  

Hi Adhemerval,

> On 20/02/2020 12:23, Lukasz Majewski wrote:
> > Hi Adhemerval,
> >   
> >> On 07/02/2020 10:00, Lukasz Majewski wrote:  
> >>> This patch provides new __utimes64 explicit 64 bit function for
> >>> setting file's 64 bit attributes for access and modification time.
> >>>
> >>> Internally, the __utimensat64_helper function is used. This patch
> >>> is necessary for having architectures with __WORDSIZE == 32 Y2038
> >>> safe.
> >>>
> >>> Moreover, a 32 bit version - __utimes has been refactored to
> >>> internally use __utimes64.
> >>>
> >>> The __utimes is now supposed to be used on systems still
> >>> supporting 32 bit time (__TIMESIZE != 64) - hence the necessary
> >>> conversion of struct timeval to 64 bit struct __timeval64.
> >>>
> >>> 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 __utimes64 and __utimes.
> >>>   
> >>
> >> LGTM with some smalls changes below.
> >>
> >> Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
> >>  
> >>> ---
> >>>  include/time.h                   |  3 +++
> >>>  sysdeps/unix/sysv/linux/utimes.c | 37
> >>> ++++++++++++++++++++++---------- 2 files changed, 29
> >>> insertions(+), 11 deletions(-)
> >>>
> >>> diff --git a/include/time.h b/include/time.h
> >>> index e38f5e32e6..b04747889a 100644
> >>> --- a/include/time.h
> >>> +++ b/include/time.h
> >>> @@ -211,8 +211,11 @@ libc_hidden_proto (__clock_getres64);
> >>>  #endif
> >>>  
> >>>  #if __TIMESIZE == 64
> >>> +# define __utimes64 __utimes
> >>>  # define __utimensat64 __utimensat
> >>>  #else
> >>> +extern int __utimes64 (const char *file, const struct __timeval64
> >>> tvp[2]); +libc_hidden_proto (__utimes64)
> >>>  extern int __utimensat64 (int fd, const char *file,
> >>>                            const struct __timespec64 tsp[2], int
> >>> flags); libc_hidden_proto (__utimensat64);    
> >>
> >> Ok.
> >>  
> >>> diff --git a/sysdeps/unix/sysv/linux/utimes.c
> >>> b/sysdeps/unix/sysv/linux/utimes.c index 121d883469..09c4e56f18
> >>> 100644 --- a/sysdeps/unix/sysv/linux/utimes.c
> >>> +++ b/sysdeps/unix/sysv/linux/utimes.c
> >>> @@ -16,22 +16,37 @@
> >>>     License along with the GNU C Library; if not, see
> >>>     <https://www.gnu.org/licenses/>.  */
> >>>  
> >>> -#include <errno.h>
> >>> -#include <stddef.h>
> >>> -#include <utime.h>
> >>> -#include <sys/time.h>
> >>> -#include <sysdep.h>
> >>> +#include <time.h>
> >>>  
> >>> +int
> >>> +__utimes64 (const char *file, const struct __timeval64 tvp[2])
> >>> +{
> >>> +  struct __timespec64 ts64[2];
> >>> +
> >>> +  if (tvp)    
> >>
> >> No implicit checks.  
> > 
> > The documentation [1] and [2] explicitly says that times (here tvp)
> > can be NULL:
> > "If times is NULL, then the access and modification times of the
> > file are set to the current time. "
> > 
> > Hence, it is perfectly valid to pass the NULL to the
> > __utimensat64_helper(). Without this check we will segfault earlier
> > (before we reach proper syscall) and introduce regression in glibc.
> >  
> 
> I meant to use:
> 
>   if (tvp != NULL)

Ach ... :-) Thanks for the clarification.

I thought that this check is not needed at all. My misunderstanding :-)


Best regards,

Lukasz Majewski

--

DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-59 Fax: (+49)-8142-66989-80 Email: lukma@denx.de