A new implementation of _setjmp/_longjmp that uses the T_FLUSHWIN trap.
This means the stack frame and program counter can restored directly from the jmp_buf, eliminating the need to backtrack through frames which does not work in all cases.
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pk
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/* $NetBSD: _setjmp.S,v 1.5 1998/07/01 02:16:27 tv Exp $ */
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/* $NetBSD: _setjmp.S,v 1.6 1999/06/27 11:10:18 pk Exp $ */
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/*
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* Copyright (c) 1992, 1993
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* The Regents of the University of California. All rights reserved.
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/*-
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* Copyright (c) 1999 The NetBSD Foundation, Inc.
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* All rights reserved.
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*
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* This software was developed by the Computer Systems Engineering group
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* at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
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* contributed to Berkeley.
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* This code is derived from software contributed to The NetBSD Foundation
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* by Paul Kranenburg.
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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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@ -18,34 +17,30 @@
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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* This product includes software developed by the NetBSD
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* Foundation, Inc. and its contributors.
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* 4. Neither the name of The NetBSD Foundation nor the names of its
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* contributors may be used to endorse or promote products derived
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* from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, 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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* from: Header: _setjmp.s,v 1.1 91/07/06 16:45:53 torek Exp
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* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
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* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
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* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
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* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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#include <machine/asm.h>
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#include <machine/trap.h>
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#if defined(LIBC_SCCS) && !defined(lint)
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#if 0
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.asciz "@(#)_setjmp.s 8.1 (Berkeley) 6/4/93"
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#else
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RCSID("$NetBSD: _setjmp.S,v 1.5 1998/07/01 02:16:27 tv Exp $")
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#endif
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RCSID("$NetBSD: _setjmp.S,v 1.6 1999/06/27 11:10:18 pk Exp $")
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#endif /* LIBC_SCCS and not lint */
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/*
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@ -55,42 +50,30 @@
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* will generate a "return(v?v:1)" from
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* the last call to
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* _setjmp(a)
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* by unwinding the call stack.
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* The previous signal state is NOT restored.
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*/
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ENTRY(_setjmp)
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st %sp, [%o0+0] /* store caller's stack pointer */
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st %o7, [%o0+4] /* ... return pc */
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st %fp, [%o0+8] /* ... and frame pointer */
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st %o7, [%o0+4] /* and the return pc */
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retl
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clr %o0 ! return 0
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ENTRY(_longjmp)
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addcc %o1, %g0, %g6 ! compute v ? v : 1 in a global register
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sub %sp, 64, %sp ! set up a local stack frame
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tst %o1 ! compute v ? v : 1
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be,a 0f
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mov 1, %g6
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mov 1, %o1
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0:
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mov %o0, %g1 ! save a in another global register
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ld [%g1+8], %g7 /* get caller's frame */
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1:
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cmp %fp, %g7 ! compare against desired frame
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bl,a 1b ! if below,
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restore ! pop frame and loop
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be,a 2f ! if there,
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ld [%g1+0], %o2 ! fetch return %sp
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t ST_FLUSHWIN ! flush register windows out to the stack
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Lbotch:
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call _C_LABEL(longjmperror) ! otherwise, went too far; bomb out
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nop
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unimp 0
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/*
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* We restore the saved stack pointer to %fp, then issue
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* a `restore' instruction which will reload the register
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* window from the stack.
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*/
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ld [%o0+4], %o7 /* restore return pc */
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ld [%o0+0], %fp /* and stack pointer */
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2:
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cmp %o2, %sp ! %sp must not decrease
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bge,a 3f
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mov %o2, %sp ! it is OK, put it in place
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b,a Lbotch
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3:
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ld [%g1+4], %o3 ! fetch pc
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jmp %o3 + 8 ! success, return %g6
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mov %g6, %o0
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retl ! success, return %g6
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restore %o1, 0, %o0
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