glibc/sysdeps/unix/sysv/linux/sigtimedwait.c
Adhemerval Zanella dafab287b4 linux: Only use 64-bit syscall if required for sigtimedwait
For !__ASSUME_TIME64_SYSCALLS there is no need to issue a 64-bit syscall
if the provided timeout fits in a 32-bit one.  The 64-bit usage should
be rare since the timeout is a relative one.

Checked on i686-linux-gnu on a 4.15 kernel and on a 5.11 kernel
(with and without --enable-kernel=5.1) and on x86_64-linux-gnu.

Reviewed-by: Lukasz Majewski <lukma@denx.de>
2021-06-22 12:09:52 -03:00

84 lines
2.5 KiB
C

/* Copyright (C) 1997-2021 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
<https://www.gnu.org/licenses/>. */
#include <signal.h>
#include <sysdep.h>
int
__sigtimedwait64 (const sigset_t *set, siginfo_t *info,
const struct __timespec64 *timeout)
{
#ifndef __NR_rt_sigtimedwait_time64
# define __NR_rt_sigtimedwait_time64 __NR_rt_sigtimedwait
#endif
int result;
#ifdef __ASSUME_TIME64_SYSCALLS
result = SYSCALL_CANCEL (rt_sigtimedwait_time64, set, info, timeout,
__NSIG_BYTES);
#else
bool need_time64 = timeout != NULL && !in_time_t_range (timeout->tv_sec);
if (need_time64)
{
result = SYSCALL_CANCEL (rt_sigtimedwait_time64, set, info, timeout,
__NSIG_BYTES);
if (result == 0 || errno != ENOSYS)
return result;
__set_errno (EOVERFLOW);
return -1;
}
else
{
struct timespec ts32, *pts32 = NULL;
if (timeout != NULL)
{
ts32 = valid_timespec64_to_timespec (*timeout);
pts32 = &ts32;
}
result = SYSCALL_CANCEL (rt_sigtimedwait, set, info, pts32,
__NSIG_BYTES);
}
#endif
/* The kernel generates a SI_TKILL code in si_code in case tkill is
used. tkill is transparently used in raise(). Since having
SI_TKILL as a code is useful in general we fold the results
here. */
if (result != -1 && info != NULL && info->si_code == SI_TKILL)
info->si_code = SI_USER;
return result;
}
#if __TIMESIZE != 64
libc_hidden_def (__sigtimedwait64)
int
__sigtimedwait (const sigset_t *set, siginfo_t *info,
const struct timespec *timeout)
{
struct __timespec64 ts64, *pts64 = NULL;
if (timeout != NULL)
{
ts64 = valid_timespec_to_timespec64 (*timeout);
pts64 = &ts64;
}
return __sigtimedwait64 (set, info, pts64);
}
#endif
libc_hidden_def (__sigtimedwait)
weak_alias (__sigtimedwait, sigtimedwait)