[PATCH v5 5/8] linux: Use long time_t __getitimer/__setitimer
Alistair Francis
alistair23@gmail.com
Fri Mar 27 18:21:44 GMT 2020
On Fri, Mar 27, 2020 at 11:09 AM Adhemerval Zanella via Libc-alpha
<libc-alpha@sourceware.org> wrote:
>
>
>
> 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>
Thanks
>
> > ---
> > 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.
I changed this to Linux/32 instead
>
> > + 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.
Linux/32 instead
>
> > + 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.
I have removed this comment.
>
> > + 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 '.
Fixed.
Alistair
>
> > + 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.
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