39ba326d65
pointer, here we keep orignal %ebp, so we can see where signal handler comes in and interrupt normal code.
80 lines
2.8 KiB
C
80 lines
2.8 KiB
C
/*-
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* Copyright (c) 2002 Jonathan Mini <mini@freebsd.org>
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* 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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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include <sys/param.h>
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#include <sys/ucontext.h>
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#include <machine/psl.h>
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#include <machine/sigframe.h>
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#include <signal.h>
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#include <strings.h>
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__weak_reference(__signalcontext, signalcontext);
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extern void _ctx_start(ucontext_t *, int argc, ...);
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int
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__signalcontext(ucontext_t *ucp, int sig, __sighandler_t *func)
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{
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register_t *p;
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struct sigframe *sfp;
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/*-
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* Set up stack.
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* (n = sizeof(int))
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* 2n+sizeof(struct sigframe) ucp
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* 2n struct sigframe
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* 1n &func
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* 0n &_ctx_start
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*/
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p = (register_t *)(void *)(intptr_t)ucp->uc_mcontext.mc_esp;
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*--p = (register_t)(intptr_t)ucp;
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p = (register_t *)((u_register_t)p & ~0xF); /* Align to 16 bytes. */
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p = (register_t *)((u_register_t)p - sizeof(struct sigframe));
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sfp = (struct sigframe *)p;
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bzero(sfp, sizeof(struct sigframe));
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sfp->sf_signum = sig;
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sfp->sf_siginfo = (register_t)(intptr_t)&sfp->sf_si;
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sfp->sf_ucontext = (register_t)(intptr_t)&sfp->sf_uc;
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sfp->sf_ahu.sf_action = (__siginfohandler_t *)func;
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bcopy(ucp, &sfp->sf_uc, sizeof(ucontext_t));
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sfp->sf_si.si_signo = sig;
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*--p = (register_t)(intptr_t)func;
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/*
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* Set up ucontext_t.
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*/
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ucp->uc_mcontext.mc_esi = ucp->uc_mcontext.mc_esp - sizeof(int);
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ucp->uc_mcontext.mc_esp = (register_t)(intptr_t)p;
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ucp->uc_mcontext.mc_eip = (register_t)(intptr_t)_ctx_start;
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ucp->uc_mcontext.mc_eflags &= ~PSL_T;
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ucp->uc_link = &sfp->sf_uc;
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sigdelset(&ucp->uc_sigmask, sig);
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return (0);
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}
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