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2433d39b69
The syscall __NR_pselect6_time64 (32-bit) or __NR_pselect6 (64-bit) is used as default. For architectures with __ASSUME_TIME64_SYSCALLS the 32-bit fallback uses __NR_select/__NR__newselect or __NR_pselect6 (it should cover the microblaze case where older kernels do not provide __NR_pselect6). Checked on x86_64-linux-gnu and i686-linux-gnu (on 5.4 and on 4.15 kernel). Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
118 lines
3.5 KiB
C
118 lines
3.5 KiB
C
/* Linux select implementation.
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Copyright (C) 2017-2020 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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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/time.h>
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#include <sys/types.h>
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#include <sys/select.h>
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#include <errno.h>
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#include <sysdep-cancel.h>
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#include <time64-support.h>
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/* Check the first NFDS descriptors each in READFDS (if not NULL) for read
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readiness, in WRITEFDS (if not NULL) for write readiness, and in EXCEPTFDS
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(if not NULL) for exceptional conditions. If TIMEOUT is not NULL, time out
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after waiting the interval specified therein. Returns the number of ready
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descriptors, or -1 for errors. */
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int
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__select64 (int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
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struct __timeval64 *timeout)
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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 = timeval64_to_timespec64 (*timeout);
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pts64 = &ts64;
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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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int r;
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if (supports_time64 ())
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{
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r = SYSCALL_CANCEL (pselect6_time64, nfds, readfds, writefds, exceptfds,
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pts64, NULL);
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/* Linux by default will update the timeout after a pselect6 syscall
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(though the pselect() glibc call suppresses this behavior).
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Since select() on Linux has the same behavior as the pselect6
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syscall, we update the timeout here. */
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if (r == 0 || errno != ENOSYS)
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{
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if (timeout != NULL)
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TIMEVAL_TO_TIMESPEC (timeout, &ts64);
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return r;
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}
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mark_time64_unsupported ();
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}
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#ifndef __ASSUME_TIME64_SYSCALLS
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struct timespec ts32, *pts32 = NULL;
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if (timeout != NULL)
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{
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if (! in_time_t_range (timeout->tv_sec))
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{
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__set_errno (EINVAL);
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return -1;
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}
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ts32 = valid_timespec64_to_timespec (ts64);
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pts32 = &ts32;
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}
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# ifndef __ASSUME_PSELECT
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# ifdef __NR__newselect
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# undef __NR_select
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# define __NR_select __NR__newselect
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# endif
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r = SYSCALL_CANCEL (select, nfds, readfds, writefds, exceptfds, pts32);
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# else
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r = SYSCALL_CANCEL (pselect6, nfds, readfds, writefds, exceptfds, pts32,
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NULL);
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# endif
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if (r >= 0 && timeout != NULL)
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*timeout = valid_timespec_to_timeval64 (ts32);
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#endif
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return r;
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}
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#if __TIMESIZE != 64
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libc_hidden_def (__select64)
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int
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__select (int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
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struct timeval *timeout)
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{
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struct __timeval64 tv64, *ptv64 = NULL;
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if (timeout != NULL)
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{
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tv64 = valid_timeval_to_timeval64 (*timeout);
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ptv64 = &tv64;
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}
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int r = __select64 (nfds, readfds, writefds, exceptfds, ptv64);
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if (r >= 0 && timeout != NULL)
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/* The remanining timeout will be always less the input TIMEOUT. */
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*timeout = valid_timeval64_to_timeval (tv64);
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return r;
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}
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#endif
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libc_hidden_def (__select)
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weak_alias (__select, select)
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weak_alias (__select, __libc_select)
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