glibc/sysdeps/unix/sysv/linux/semtimedop.c
Adhemerval Zanella eef7913c2f linux: Only use 64-bit syscall if required for semtimedop
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

87 lines
2.7 KiB
C

/* Copyright (C) 1995-2021 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@cygnus.com>, August 1995.
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 <sys/sem.h>
#include <ipc_priv.h>
#include <sysdep.h>
#include <errno.h>
static int
semtimedop_syscall (int semid, struct sembuf *sops, size_t nsops,
const struct __timespec64 *timeout)
{
#ifdef __NR_semtimedop_time64
return INLINE_SYSCALL_CALL (semtimedop_time64, semid, sops, nsops, timeout);
#elif defined __ASSUME_DIRECT_SYSVIPC_SYSCALLS && defined __NR_semtimedop
return INLINE_SYSCALL_CALL (semtimedop, semid, sops, nsops, timeout);
#else
return INLINE_SYSCALL_CALL (ipc, IPCOP_semtimedop, semid,
SEMTIMEDOP_IPC_ARGS (nsops, sops, timeout));
#endif
}
/* Perform user-defined atomical operation of array of semaphores. */
int
__semtimedop64 (int semid, struct sembuf *sops, size_t nsops,
const struct __timespec64 *timeout)
{
#ifdef __ASSUME_TIME64_SYSCALLS
return semtimedop_syscall (semid, sops, nsops, timeout);
#else
bool need_time64 = timeout != NULL && !in_time_t_range (timeout->tv_sec);
if (need_time64)
{
int r = semtimedop_syscall (semid, sops, nsops, timeout);
if (r == 0 || errno != ENOSYS)
return r;
__set_errno (EOVERFLOW);
return -1;
}
struct timespec ts32, *pts32 = NULL;
if (timeout != NULL)
{
ts32 = valid_timespec64_to_timespec (*timeout);
pts32 = &ts32;
}
# ifdef __ASSUME_DIRECT_SYSVIPC_SYSCALLS
return INLINE_SYSCALL_CALL (semtimedop, semid, sops, nsops, pts32);
# else
return INLINE_SYSCALL_CALL (ipc, IPCOP_semtimedop, semid,
SEMTIMEDOP_IPC_ARGS (nsops, sops, pts32));
# endif
#endif
}
#if __TIMESIZE != 64
libc_hidden_def (__semtimedop64)
int
__semtimedop (int semid, struct sembuf *sops, size_t nsops,
const struct timespec *timeout)
{
struct __timespec64 ts64, *pts64 = NULL;
if (timeout != NULL)
{
ts64 = valid_timespec_to_timespec64 (*timeout);
pts64 = &ts64;
}
return __semtimedop64 (semid, sops, nsops, pts64);
}
#endif
weak_alias (__semtimedop, semtimedop)