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/* $OpenBSD: setjmp.S,v 1.6 2011/11/22 21:13:30 guenther Exp $ */
/*
* Copyright (c) 1992, 1993
* The Regents of the University of California. All rights reserved.
*
* This software was developed by the Computer Systems Engineering group
* at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
* contributed to Berkeley.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/*
* C library -- setjmp, longjmp
*
* longjmp(a,v)
* will generate a "return(v)" from
* the last call to
* setjmp(a)
* by restoring registers from the stack,
* and a struct sigcontext, see <signal.h>
*/
#include "SYS.h"
ENTRY(setjmp)
/*
* We use the caller's `arg dump' area (%sp+0x44; there are 6 ints
* reserved there for us) to avoid having to allocate stack space
* here.
*/
mov %o0, %o2 /* build sigcontext in [%o2] */
mov 1, %o0 /* SIG_BLOCK */
mov SYS_sigprocmask, %g1
clr %o1 /* sigprocmask(SIG_BLOCK, (sigset_t *)NULL) */
t ST_SYSCALL
st %o0, [%o2 + 4] /* sc.sc_mask = current mask; */
mov SYS_sigaltstack, %g1
clr %o0 /* sigaltstack(NULL, &foo) */
add %sp, 0x48, %o1 /* (foo being in arg dump area) */
t ST_SYSCALL
ld [%sp + 0x50], %o0 /* foo.ss_flags */
and %o0, 1, %o1 /* onstack = foo.ss_flags & 1; */
st %o0, [%o2 + 0] /* sc.sc_onstack = current onstack; */
st %sp, [%o2 + 8] /* sc.sc_sp = sp (both ours and caller's) */
add %o7, 8, %o0
st %o0, [%o2 + 12] /* sc.sc_pc = return_pc */
add %o7, 12, %o0
st %o0, [%o2 + 16] /* sc.sc_npc = return_pc + 4 */
st %g0, [%o2 + 20] /* sc.sc_psr = (clean psr) */
st %fp, [%o2 + 24] /* sc.sc_g1 = %fp (misuse, but what the heck) */
/* sc.sc_o0 = random(), set in longjmp */
retl /* return 0 */
clr %o0
/*
* All we need to do here is force sigreturn to load a new stack pointer,
* new <pc,npc>, and appropriate %o0 return value from the sigcontext built
* in setjmp. The %i and %l registers will be reloaded from the place to
* which %sp points, due to sigreturn() semantics (sigreturn does not modify
* the window pointer in the psr, hence it must force all windows to reload).
*/
ENTRY(longjmp)
save %sp, -96, %sp
ld [%i0 + 8], %o2 /* make sure sc->sc_sp, sc->sc_fp nonzero */
ld [%i0 + 24], %o3
orcc %o2, %o3, %g0
bz Lbotch
tst %i1 /* if (v == 0) v = 1; */
bz,a 1f
mov 1, %i1
1:
st %i1, [%i0 + 28] /* sc.sc_o0 = v; */
mov SYS_sigreturn, %g1
mov %i0, %o0
t ST_SYSCALL /* sigreturn(scp); */
Lbotch:
/* oops, caller botched it */
call _C_LABEL(longjmperror)
nop
unimp 0
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