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91cf411ad3
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. This also avoids the need to use supports_time64() (which breaks the usage case of live migration like CRIU or similar). 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>
95 lines
3.0 KiB
C
95 lines
3.0 KiB
C
/* Copyright (C) 2006-2021 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed by Ulrich Drepper <drepper@redhat.com>, 2006.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<https://www.gnu.org/licenses/>. */
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#include <sys/select.h>
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#include <sysdep-cancel.h>
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static int
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pselect64_syscall (int nfds, fd_set *readfds, fd_set *writefds,
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fd_set *exceptfds, const struct __timespec64 *timeout,
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const sigset_t *sigmask)
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{
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#ifndef __NR_pselect6_time64
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# define __NR_pselect6_time64 __NR_pselect6
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#endif
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/* NB: This is required by ARGIFY used in x32 internal_syscallN. */
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__syscall_ulong_t data[2] =
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{
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(uintptr_t) sigmask, __NSIG_BYTES
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};
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return SYSCALL_CANCEL (pselect6_time64, nfds, readfds, writefds, exceptfds,
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timeout, data);
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}
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int
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__pselect64 (int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
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const struct __timespec64 *timeout, const sigset_t *sigmask)
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{
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/* The Linux kernel can in some situations update the timeout value.
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We do not want that so use a local variable. */
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struct __timespec64 tval;
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if (timeout != NULL)
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{
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tval = *timeout;
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timeout = &tval;
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}
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/* Note: the system call expects 7 values but on most architectures
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we can only pass in 6 directly. If there is an architecture with
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support for more parameters a new version of this file needs to
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be created. */
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#ifdef __ASSUME_TIME64_SYSCALLS
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return pselect64_syscall (nfds, readfds, writefds, exceptfds, timeout,
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sigmask);
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#else
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bool need_time64 = timeout != NULL && !in_time_t_range (timeout->tv_sec);
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if (need_time64)
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{
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int r = pselect64_syscall (nfds, readfds, writefds, exceptfds, timeout,
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sigmask);
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if (r == 0 || errno != ENOSYS)
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return r;
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__set_errno (EOVERFLOW);
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return -1;
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}
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return __pselect32 (nfds, readfds, writefds, exceptfds, timeout, sigmask);
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#endif
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}
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#if __TIMESIZE != 64
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libc_hidden_def (__pselect64)
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int
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__pselect (int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
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const struct timespec *timeout, const sigset_t *sigmask)
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{
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struct __timespec64 ts64, *pts64 = NULL;
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if (timeout != NULL)
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{
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ts64 = valid_timespec_to_timespec64 (*timeout);
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pts64 = &ts64;
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}
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return __pselect64 (nfds, readfds, writefds, exceptfds, pts64, sigmask);
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}
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#endif
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#ifndef __pselect
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weak_alias (__pselect, pselect)
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#endif
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