[PATCH v5 5/8] linux: Use long time_t __getitimer/__setitimer

[Adhemerval Zanella]

On 03/03/2020 14:53, Alistair Francis wrote:
> The Linux kernel expects itimerval to use a 32-bit time_t, even on archs
> with a 64-bit time_t (like RV32). To address this let's convert
> itimerval to/from 32-bit and 64-bit to ensure the kernel always gets
> a 32-bit time_t.
> 
> While we are converting these functions let's also convert them to be
> the y2038 safe versions. This means there is a *64 function that is
> called by a backwards compatible wrapper.
> 
> Tested-by: Lukasz Majewski <lukma@denx.de>

Ok, with some nits below.

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

> ---
>  include/time.h                        | 15 +++++
>  sysdeps/unix/syscalls.list            |  2 -
>  sysdeps/unix/sysv/linux/getitimer.c   | 59 +++++++++++++++++
>  sysdeps/unix/sysv/linux/setitimer.c   | 95 +++++++++++++++++++++++++++
>  sysdeps/unix/sysv/linux/tv32-compat.h | 31 +++++++++
>  5 files changed, 200 insertions(+), 2 deletions(-)
>  create mode 100644 sysdeps/unix/sysv/linux/getitimer.c
>  create mode 100644 sysdeps/unix/sysv/linux/setitimer.c
>  create mode 100644 sysdeps/unix/sysv/linux/tv32-compat.h
> 
> diff --git a/include/time.h b/include/time.h
> index e70258e8e3..df3ee55893 100644
> --- a/include/time.h
> +++ b/include/time.h
> @@ -6,6 +6,7 @@
>  # include <bits/types/locale_t.h>
>  # include <stdbool.h>
>  # include <time/mktime-internal.h>
> +# include <sys/time.h>
>  # include <endian.h>
>  # include <time-clockid.h>
>  # include <sys/time.h>
> @@ -127,6 +128,20 @@ struct __itimerval64
>  };
>  #endif
>  
> +#if __TIMESIZE == 64
> +# define __getitimer64 __getitimer
> +# define __setitimer64 __setitimer
> +#else
> +extern int __getitimer64 (enum __itimer_which __which,
> +                          struct __itimerval64 *__value);
> +
> +libc_hidden_proto (__getitimer64)
> +extern int __setitimer64 (enum __itimer_which __which,
> +                          const struct __itimerval64 *__restrict __new,
> +                          struct __itimerval64 *__restrict __old);
> +libc_hidden_proto (__setitimer64)
> +#endif
> +
>  #if __TIMESIZE == 64
>  # define __ctime64 ctime
>  #else

Ok.

> diff --git a/sysdeps/unix/syscalls.list b/sysdeps/unix/syscalls.list
> index e28e801c7a..d249049d6e 100644
> --- a/sysdeps/unix/syscalls.list
> +++ b/sysdeps/unix/syscalls.list
> @@ -25,7 +25,6 @@ getgid		-	getgid		Ei:	__getgid	getgid
>  getgroups	-	getgroups	i:ip	__getgroups	getgroups
>  gethostid	-	gethostid	i:	gethostid
>  gethostname	-	gethostname	i:bn	__gethostname	gethostname
> -getitimer	-	getitimer	i:ip	__getitimer	getitimer
>  getpeername	-	getpeername	i:ibN	__getpeername	getpeername
>  getpid		-	getpid		Ei:	__getpid	getpid
>  getpriority	-	getpriority	i:ii	__getpriority	getpriority
> @@ -67,7 +66,6 @@ setgid		-	setgid		i:i	__setgid	setgid
>  setgroups	-	setgroups	i:ip	setgroups
>  sethostid	-	sethostid	i:i	sethostid
>  sethostname	-	sethostname	i:pi	sethostname
> -setitimer	-	setitimer	i:ipp	__setitimer	setitimer
>  setpgid		-	setpgrp		i:ii	__setpgid	setpgid
>  setpriority	-	setpriority	i:iii	__setpriority	setpriority
>  setregid	-	setregid	i:ii	__setregid	setregid

Ok.

> diff --git a/sysdeps/unix/sysv/linux/getitimer.c b/sysdeps/unix/sysv/linux/getitimer.c
> new file mode 100644
> index 0000000000..12f7963949
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/getitimer.c
> @@ -0,0 +1,59 @@
> +/* getitimer -- Get the state of an interval timer.  Linux/tv32 version.

I think tv32 is misleading, since it does handle 64 bit time_t when
kernel supports it.

> +   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; if not, see
> +   <http://www.gnu.org/licenses/>.  */
> +
> +#include <time.h>
> +#include <sys/time.h>
> +#include <sys/types.h>
> +#include <sysdep.h>
> +#include <tv32-compat.h>
> +
> +int
> +__getitimer64 (__itimer_which_t which, struct __itimerval64 *curr_value)
> +{
> +#if __KERNEL_OLD_TIMEVAL_MATCHES_TIMEVAL64
> +  return INLINE_SYSCALL_CALL (getitimer, which, curr_value);
> +#else
> +  struct __itimerval32 curr_value_32;
> +  if (INLINE_SYSCALL_CALL (getitimer, which, &curr_value_32) == -1)
> +    return -1;
> +
> +  /* Write all fields of 'curr_value' regardless of overflow.  */
> +  curr_value->it_interval
> +    = valid_timeval32_to_timeval64 (curr_value_32.it_interval);
> +  curr_value->it_value
> +    = valid_timeval32_to_timeval64 (curr_value_32.it_value);
> +  return 0;
> +#endif
> +}

Ok.

> +
> +#if __TIMESIZE != 64
> +libc_hidden_def (__getitimer64)
> +int
> +__getitimer (__itimer_which_t which, struct itimerval *curr_value)
> +{
> +  struct __itimerval64 val64;
> +
> +  val64.it_interval
> +    = valid_timeval_to_timeval64 (curr_value->it_interval);
> +  val64.it_value
> +    = valid_timeval_to_timeval64 (curr_value->it_value);
> +
> +  return __getitimer64 (which, &val64);
> +}
> +#endif
> +weak_alias (__getitimer, getitimer)

Ok.

> diff --git a/sysdeps/unix/sysv/linux/setitimer.c b/sysdeps/unix/sysv/linux/setitimer.c
> new file mode 100644
> index 0000000000..238853dd33
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/setitimer.c
> @@ -0,0 +1,95 @@
> +/* setitimer -- Set the state of an interval timer.  Linux/tv32 version.

Same as before.

> +   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; if not, see
> +   <http://www.gnu.org/licenses/>.  */
> +
> +#include <time.h>
> +#include <sys/time.h>
> +#include <sys/types.h>
> +#include <sysdep.h>
> +#include <tv32-compat.h>
> +
> +int
> +__setitimer64 (__itimer_which_t which,
> +               const struct __itimerval64 *restrict new_value,
> +               struct __itimerval64 *restrict old_value)
> +{
> +#if __KERNEL_OLD_TIMEVAL_MATCHES_TIMEVAL64
> +  return INLINE_SYSCALL_CALL (setitimer, which, new_value, old_value);

Ok.

> +#else
> +  struct __itimerval32 new_value_32;
> +
> +  if (! in_time_t_range (new_value->it_interval.tv_sec))
> +  {
> +    __set_errno (EOVERFLOW);
> +    return -1;
> +  }
> +  new_value_32.it_interval
> +    = valid_timeval64_to_timeval32 (new_value->it_interval);
> +
> +  if (! in_time_t_range (new_value->it_value.tv_sec))
> +  {
> +    __set_errno (EOVERFLOW);
> +    return -1;
> +  }
> +  new_value_32.it_value
> +    = valid_timeval64_to_timeval32 (new_value->it_value);

Ok, although MUSL return ENOSUP in such case. IMHO EOVERFLOW does
make more sense here.

> +
> +  if (old_value == NULL)
> +    return INLINE_SYSCALL_CALL (setitimer, which, &new_value_32, NULL);
> +

Ok.

> +  struct __itimerval32 old_value_32;
> +  if (INLINE_SYSCALL_CALL (setitimer, which, &new_value_32, &old_value_32) == -1)
> +    return -1;
> +
> +  /* Write all fields of 'old_value' regardless of overflow.  */

What do you mean by 'overflow' here?  The returned kernel value should
be a timeval with 32-bit value and if it is being called by __setitimer
it should not overflow.

> +  old_value->it_interval
> +     = valid_timeval32_to_timeval64 (old_value_32.it_interval);
> +  old_value->it_value
> +     = valid_timeval32_to_timeval64 (old_value_32.it_value);
> +  return 0;
> +#endif
> +}
> +

Ok.

> +#if __TIMESIZE != 64
> +libc_hidden_def (__setitimer64)
> +int
> +__setitimer (__itimer_which_t which,
> +             const struct itimerval *restrict new_value,
> +             struct itimerval *restrict old_value)
> +{
> +  int ret;
> +  struct __itimerval64 new64, old64;
> +
> +  new64.it_interval
> +    = valid_timeval_to_timeval64 (new_value->it_interval);
> +  new64.it_value
> +    = valid_timeval_to_timeval64 (new_value->it_value);
> +
> +  ret = __setitimer64 (which, &new64, old_value ? &old64 : NULL);
> +
> +  if (ret == 0 && old_value)
> +    {
> +      old_value->it_interval
> +        = valid_timeval64_to_timeval (old64.it_interval);
> +      old_value->it_value
> +        = valid_timeval64_to_timeval (old64.it_value);
> +    }
> +
> +  return ret;
> +}
> +#endif
> +weak_alias (__setitimer, setitimer)

Ok.

> diff --git a/sysdeps/unix/sysv/linux/tv32-compat.h b/sysdeps/unix/sysv/linux/tv32-compat.h
> new file mode 100644
> index 0000000000..b8791b1db8
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/tv32-compat.h
> @@ -0,0 +1,31 @@
> +/* Compatibility definitions for `struct timeval' with 32-bit time_t.

Change ` to '.

> +   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; if not, see
> +   <http://www.gnu.org/licenses/>.  */
> +
> +#ifndef _TV32_COMPAT_H
> +#define _TV32_COMPAT_H 1
> +
> +#include <bits/types/time_t.h>
> +
> +/* Structures containing 'struct timeval' with 32-bit time_t.  */
> +struct __itimerval32
> +{
> +  struct __timeval32 it_interval;
> +  struct __timeval32 it_value;
> +};
> +
> +#endif /* tv32-compat.h */
> 

Ok.