bdccf0bbac
As per r177853, we need to avoid using errno inside user mutex code, since signal handlers can interfere with it and mess up libthr internal state. So, implement _umtx_op_err() instead, which makes a raw syscall and returns the error value directly instead of using errno. Approved by: jhibbits (mentor) Differential Revision: https://reviews.freebsd.org/D20946
97 lines
2.7 KiB
C
97 lines
2.7 KiB
C
/*-
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* SPDX-License-Identifier: BSD-3-Clause
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*
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* Copyright 2004 by Peter Grehan. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. The name of the author may not be used to endorse or promote products
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* derived from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* $FreeBSD$
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*/
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/*
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* Machine-dependent thread prototypes/definitions.
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*/
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#ifndef _PTHREAD_MD_H_
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#define _PTHREAD_MD_H_
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#include <stddef.h>
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#include <sys/types.h>
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#define CPU_SPINWAIT
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#define DTV_OFFSET offsetof(struct tcb, tcb_dtv)
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#ifdef __powerpc64__
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#define TP_OFFSET 0x7010
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#else
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#define TP_OFFSET 0x7008
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#endif
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/*
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* Variant I tcb. The structure layout is fixed, don't blindly
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* change it.
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* %r2 (32-bit) or %r13 (64-bit) points to end of the structure.
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*/
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struct tcb {
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void *tcb_dtv;
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struct pthread *tcb_thread;
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};
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static __inline void
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_tcb_set(struct tcb *tcb)
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{
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#ifdef __powerpc64__
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__asm __volatile("mr 13,%0" ::
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"r"((uint8_t *)tcb + TP_OFFSET));
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#else
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__asm __volatile("mr 2,%0" ::
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"r"((uint8_t *)tcb + TP_OFFSET));
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#endif
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}
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static __inline struct tcb *
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_tcb_get(void)
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{
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register struct tcb *tcb;
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#ifdef __powerpc64__
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__asm __volatile("addi %0,13,%1" : "=r"(tcb) : "i"(-TP_OFFSET));
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#else
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__asm __volatile("addi %0,2,%1" : "=r"(tcb) : "i"(-TP_OFFSET));
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#endif
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return (tcb);
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}
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static __inline struct pthread *
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_get_curthread(void)
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{
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if (_thr_initial)
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return (_tcb_get()->tcb_thread);
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return (NULL);
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}
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#define HAS__UMTX_OP_ERR 1
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#endif /* _PTHREAD_MD_H_ */
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