Re: [PATCH] y2038: linux: Provide __sched_rr_get_interval64 implementation

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

On 08/01/2020 13:22, Lukasz Majewski wrote:
> This patch replaces auto generated wrapper (as described in
> sysdeps/unix/sysv/linux/syscalls.list) for sched_rr_get_interval with one which
> adds extra support for reading 64 bit time values on machines with
> __TIMESIZE != 64.
> There is no functional change for architectures already supporting 64 bit
> time ABI.
> 
> The sched_rr_get_interval declaration in ./include/sched.h is not followed by
> corresponding libc_hidden_proto(), so it has been assumed that newly introduced
> syscall wrapper doesn't require libc_hidden_def() (which has been added by
> template used with auto generation script).
> 
> Moreover, the code for building sched_rr_gi.c file is already placed in
> ./posix/Makefiles, so there was no need to add it elsewhere.
> 
> Performed tests and validation are the same as for timer_gettime() conversion
> (sysdeps/unix/sysv/linux/timer_gettime.c).

LGTM, thanks.

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

> ---
>  include/time.h                        |  7 +++
>  sysdeps/unix/sysv/linux/sched_rr_gi.c | 73 +++++++++++++++++++++++++++
>  sysdeps/unix/sysv/linux/syscalls.list |  1 -
>  3 files changed, 80 insertions(+), 1 deletion(-)
>  create mode 100644 sysdeps/unix/sysv/linux/sched_rr_gi.c
> 
> diff --git a/include/time.h b/include/time.h
> index f23bfea737..558923274a 100644
> --- a/include/time.h
> +++ b/include/time.h
> @@ -203,6 +203,13 @@ libc_hidden_proto (__timer_settime64);
>  libc_hidden_proto (__timerfd_settime64);
>  #endif
>  
> +#if __TIMESIZE == 64
> +# define __sched_rr_get_interval64 __sched_rr_get_interval
> +#else
> +extern int __sched_rr_get_interval64 (pid_t pid, struct __timespec64 *tp);
> +libc_hidden_proto (__sched_rr_get_interval64);
> +#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.

Ok.

> diff --git a/sysdeps/unix/sysv/linux/sched_rr_gi.c b/sysdeps/unix/sysv/linux/sched_rr_gi.c
> new file mode 100644
> index 0000000000..3d7b484591
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/sched_rr_gi.c
> @@ -0,0 +1,73 @@
> +/* sched_rr_get_interval -- get the scheduler's SCHED_RR policy time interval.
> +   Copyright (C) 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; see the file COPYING.LIB.  If
> +   not, see <https://www.gnu.org/licenses/>.  */
> +
> +#include <errno.h>
> +#include <stdlib.h>
> +#include <time.h>
> +#include <sysdep.h>
> +#include <kernel-features.h>
> +
> +int
> +__sched_rr_get_interval64 (pid_t pid, struct __timespec64 *tp)
> +{
> +#ifdef __ASSUME_TIME64_SYSCALLS
> +# ifndef __NR_sched_rr_get_interval_time64
> +#  define __NR_sched_rr_get_interval_time64 __NR_sched_rr_get_interval
> +# endif
> +  return INLINE_SYSCALL_CALL (sched_rr_get_interval_time64, pid, tp);

Ok.

> +#else
> +# ifdef __NR_sched_rr_get_interval_time64
> +  int ret = INLINE_SYSCALL_CALL (sched_rr_get_interval_time64, pid, tp);
> +  if (ret == 0 || errno != ENOSYS)
> +    return ret;
> +# endif
> +  struct timespec tp32;
> +  int retval = INLINE_SYSCALL_CALL (sched_rr_get_interval, pid, &tp32);
> +  if (retval == 0)
> +    *tp = valid_timespec_to_timespec64 (tp32);
> +
> +  return retval;
> +#endif
> +}

Ok.

> +
> +#if __TIMESIZE != 64
> +libc_hidden_def (__sched_rr_get_interval64)
> +
> +int
> +__sched_rr_get_interval (pid_t pid, struct timespec *tp)
> +{
> +  int ret;
> +  struct __timespec64 tp64;
> +
> +  ret = __sched_rr_get_interval64 (pid, &tp64);
> +
> +  if (ret == 0)
> +    {
> +      if (! in_time_t_range (tp64.tv_sec))
> +        {
> +          __set_errno (EOVERFLOW);
> +          return -1;
> +        }
> +
> +      *tp = valid_timespec64_to_timespec (tp64);
> +    }
> +
> +  return ret;
> +}
> +#endif
> +strong_alias (__sched_rr_get_interval, sched_rr_get_interval)

Ok.

> diff --git a/sysdeps/unix/sysv/linux/syscalls.list b/sysdeps/unix/sysv/linux/syscalls.list
> index 1fa546f231..5d65ed23e0 100644
> --- a/sysdeps/unix/sysv/linux/syscalls.list
> +++ b/sysdeps/unix/sysv/linux/syscalls.list
> @@ -51,7 +51,6 @@ sched_getp	-	sched_getparam	i:ip	__sched_getparam	sched_getparam
>  sched_gets	-	sched_getscheduler	i:i	__sched_getscheduler	sched_getscheduler
>  sched_primax	-	sched_get_priority_max	i:i	__sched_get_priority_max	sched_get_priority_max
>  sched_primin	-	sched_get_priority_min	i:i	__sched_get_priority_min	sched_get_priority_min
> -sched_rr_gi	-	sched_rr_get_interval	i:ip	__sched_rr_get_interval	sched_rr_get_interval
>  sched_setp	-	sched_setparam	i:ip	__sched_setparam	sched_setparam
>  sched_sets	-	sched_setscheduler	i:iip	__sched_setscheduler	sched_setscheduler
>  sched_yield	-	sched_yield	i:	__sched_yield	sched_yield
> 

Ok.