Re: [PATCH 5/5] y2038: linux: Provide __timer_settime64 implementation

[Lukasz Majewski <lukma at denx dot de>]

Dear All,

> This patch provides new __timer_settime64 explicit 64 bit function
> for setting flags, interval and value of specified timer.
> Moreover, a 32 bit version - __timer_settime has been refactored to
> internally use __timer_settime64.
> 
> The __timer_settime is now supposed to be used on systems still
> supporting 32 bit time (__TIMESIZE != 64) - hence the necessary
> conversion to 64 bit struct __timespec64 from struct timespec (and
> opposite when old_value pointer is provided).
> 
> The new __timer_settime64 syscall available from Linux 5.1+ has been
> used, when applicable.
> 
> Build tests:
> - The code has been tested on x86_64/x86 (native compilation):
> make PARALLELMFLAGS="-j8" && make check PARALLELMFLAGS="-j8" && \\
> make xcheck PARALLELMFLAGS="-j8"
> 
> - The glibc has been build tested (make PARALLELMFLAGS="-j8") for
> x86 (i386), x86_64-x32, and armv7
> 
> 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
> 
> - Use of cross-test-ssh.sh for ARM (armv7):
>   make PARALLELMFLAGS="-j8" test-wrapper='./cross-test-ssh.sh
> root@192.168.7.2' xcheck
> 
> Linux kernel, headers and minimal kernel version for glibc build test
> matrix:
> - Linux v5.1 (with timer_settime64) and glibc build with v5.1 as
>   minimal kernel version (--enable-kernel="5.1.0")
>   The __ASSUME_TIME64_SYSCALLS flag defined.
> 
> - Linux v5.1 and default minimal kernel version
>   The __ASSUME_TIME64_SYSCALLS not defined, but kernel supports
> timer_settime64 syscall.
> 
> - Linux v4.19 (no timer_settime64 support) with default minimal
> kernel version for contemporary glibc (3.2.0)
>   This kernel doesn't support timer_settime64 syscall, so the
> fallback to timer_settime is tested.
> 
> Above tests were performed with Y2038 redirection applied as well as
> without (so the __TIMESIZE != 64 execution path is checked as well).
> 
> No regressions were observed.
> ---
>  include/time.h                          |  9 ++++
>  sysdeps/unix/sysv/linux/timer_settime.c | 68
> ++++++++++++++++++++++--- 2 files changed, 71 insertions(+), 6
> deletions(-)
> 
> diff --git a/include/time.h b/include/time.h
> index 8b9a4b7a60..a46fd2f08a 100644
> --- a/include/time.h
> +++ b/include/time.h
> @@ -186,6 +186,15 @@ extern int __timer_gettime64 (timer_t timerid,
> struct __itimerspec64 *value); libc_hidden_proto (__timer_gettime64);
>  #endif
>  
> +#if __TIMESIZE == 64
> +# define __timer_settime64 __timer_settime
> +#else
> +extern int __timer_settime64 (timer_t timerid, int flags,
> +                              const struct __itimerspec64 *value,
> +                              struct __itimerspec64 *ovalue);
> +libc_hidden_proto (__timer_settime64);
> +#endif
> +
>  /* Compute the `struct tm' representation of T,
>     offset OFFSET seconds east of UTC,
>     and store year, yday, mon, mday, wday, hour, min, sec into *TP.
> diff --git a/sysdeps/unix/sysv/linux/timer_settime.c
> b/sysdeps/unix/sysv/linux/timer_settime.c index
> 51f24200aa..f847e3e44a 100644 ---
> a/sysdeps/unix/sysv/linux/timer_settime.c +++
> b/sysdeps/unix/sysv/linux/timer_settime.c @@ -20,17 +20,73 @@
>  #include <stdlib.h>
>  #include <time.h>
>  #include <sysdep.h>
> +#include <kernel-features.h>
>  #include "kernel-posix-timers.h"
>  
>  int
> -timer_settime (timer_t timerid, int flags, const struct itimerspec
> *value,
> -	       struct itimerspec *ovalue)
> +__timer_settime64 (timer_t timerid, int flags,
> +                   const struct __itimerspec64 *value,
> +                   struct __itimerspec64 *ovalue)
>  {
>    struct timer *kt = (struct timer *) timerid;
>  
> -  /* Delete the kernel timer object.  */
> -  int res = INLINE_SYSCALL (timer_settime, 4, kt->ktimerid, flags,
> -			    value, ovalue);
> +#ifdef __ASSUME_TIME64_SYSCALLS
> +# ifndef __NR_timer_settime64
> +#  define __NR_timer_settime64 __NR_timer_settime
> +# endif
> +  return INLINE_SYSCALL (timer_settime64, 4, kt->ktimerid, flags,
> value,
> +                         ovalue);
> +#else
> +# ifdef __NR_timer_settime64
> +  int ret = INLINE_SYSCALL (timer_settime64, 4, kt->ktimerid, flags,
> value,
> +                            ovalue);
> +  if (ret == 0 || errno != ENOSYS)
> +    return ret;
> +# endif
> +  struct itimerspec its32, oits32;
>  
> -  return res;
> +  if (! in_time_t_range ((value->it_value).tv_sec)
> +      || ! in_time_t_range ((value->it_interval).tv_sec))
> +    {
> +      __set_errno (EOVERFLOW);
> +      return -1;
> +    }
> +
> +  its32.it_interval = valid_timespec64_to_timespec
> (value->it_interval);
> +  its32.it_value = valid_timespec64_to_timespec (value->it_value);
> +
> +  int retval = INLINE_SYSCALL (timer_settime, 4, kt->ktimerid, flags,
> +                               &its32, ovalue ? &oits32 : NULL);
> +  if (! retval && ovalue)
> +    {
> +      ovalue->it_interval = valid_timespec_to_timespec64
> (oits32.it_interval);
> +      ovalue->it_value = valid_timespec_to_timespec64
> (oits32.it_value);
> +    }
> +
> +  return retval;
> +#endif
> +}
> +
> +#if __TIMESIZE != 64
> +int
> +__timer_settime (timer_t timerid, int flags, const struct itimerspec
> *value,
> +                 struct itimerspec *ovalue)
> +{
> +  struct __itimerspec64 its64, oits64;
> +  int retval;
> +
> +  its64.it_interval = valid_timespec_to_timespec64
> (value->it_interval);
> +  its64.it_value = valid_timespec_to_timespec64 (value->it_value);
> +
> +  retval = __timer_settime64 (timerid, flags, &its64, ovalue ?
> &oits64 : NULL);
> +  if (! retval && ovalue)
> +    {
> +      ovalue->it_interval = valid_timespec64_to_timespec
> (oits64.it_interval);
> +      ovalue->it_value = valid_timespec64_to_timespec
> (oits64.it_value);
> +    }
> +
> +  return retval;
>  }
> +#endif
> +weak_alias (__timer_settime, timer_settime)
> +libc_hidden_def (timer_settime)

Gentle ping,


Best regards,

Lukasz Majewski

--

DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
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Phone: (+49)-8142-66989-59 Fax: (+49)-8142-66989-80 Email: lukma@denx.de

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