glibc/sysdeps/unix/sysv/linux/clock_nanosleep.c
Adhemerval Zanella 6d97330d7a linux: Only use 64-bit syscall if required for clock_nanosleep
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

102 lines
3.2 KiB
C

/* Copyright (C) 2003-2021 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 <time.h>
#include <kernel-features.h>
#include <errno.h>
#include <sysdep-cancel.h>
#include "kernel-posix-cpu-timers.h"
#include <shlib-compat.h>
/* We can simply use the syscall. The CPU clocks are not supported
with this function. */
int
__clock_nanosleep_time64 (clockid_t clock_id, int flags,
const struct __timespec64 *req,
struct __timespec64 *rem)
{
if (clock_id == CLOCK_THREAD_CPUTIME_ID)
return EINVAL;
if (clock_id == CLOCK_PROCESS_CPUTIME_ID)
clock_id = MAKE_PROCESS_CPUCLOCK (0, CPUCLOCK_SCHED);
/* If the call is interrupted by a signal handler or encounters an error,
it returns a positive value similar to errno. */
#ifndef __NR_clock_nanosleep_time64
# define __NR_clock_nanosleep_time64 __NR_clock_nanosleep
#endif
int r;
#ifdef __ASSUME_TIME64_SYSCALLS
r = INTERNAL_SYSCALL_CANCEL (clock_nanosleep_time64, clock_id, flags, req,
rem);
#else
if (!in_time_t_range (req->tv_sec))
{
r = INTERNAL_SYSCALL_CANCEL (clock_nanosleep_time64, clock_id, flags,
req, rem);
if (r == -ENOSYS)
r = -EOVERFLOW;
}
else
{
struct timespec tr32;
struct timespec ts32 = valid_timespec64_to_timespec (*req);
r = INTERNAL_SYSCALL_CANCEL (clock_nanosleep, clock_id, flags, &ts32,
&tr32);
if (INTERNAL_SYSCALL_ERROR_P (r))
{
if (r == -EINTR && rem != NULL && (flags & TIMER_ABSTIME) == 0)
*rem = valid_timespec_to_timespec64 (tr32);
}
}
#endif
return -r;
}
#if __TIMESIZE != 64
libc_hidden_def (__clock_nanosleep_time64)
int
__clock_nanosleep (clockid_t clock_id, int flags, const struct timespec *req,
struct timespec *rem)
{
int r;
struct __timespec64 treq64, trem64;
treq64 = valid_timespec_to_timespec64 (*req);
r = __clock_nanosleep_time64 (clock_id, flags, &treq64,
rem != NULL ? &trem64 : NULL);
if (r == EINTR && rem != NULL && (flags & TIMER_ABSTIME) == 0)
*rem = valid_timespec64_to_timespec (trem64);
return r;
}
#endif
libc_hidden_def (__clock_nanosleep)
versioned_symbol (libc, __clock_nanosleep, clock_nanosleep, GLIBC_2_17);
/* clock_nanosleep moved to libc in version 2.17;
old binaries may expect the symbol version it had in librt. */
#if SHLIB_COMPAT (libc, GLIBC_2_2, GLIBC_2_17)
strong_alias (__clock_nanosleep, __clock_nanosleep_2);
compat_symbol (libc, __clock_nanosleep_2, clock_nanosleep, GLIBC_2_2);
#endif