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/*
* Copyright (c) 2003 Marcel Moolenaar
* All rights reserved.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/types.h>
#include <sys/ucontext.h>
#include <machine/fpu.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <strings.h>
struct fdesc {
uint64_t ip;
uint64_t gp;
};
typedef void (*handler_t)(uint64_t, uint64_t, uint64_t);
static __inline uint64_t *
spill(uint64_t *bsp, uint64_t arg)
{
*bsp++ = arg;
if (((intptr_t)bsp & 0x1ff) == 0x1f8)
*bsp++ = 0;
return (bsp);
}
static void
ctx_wrapper(ucontext_t *ucp, handler_t func, uint64_t *args)
{
(*func)(args[0], args[1], args[2]);
if (ucp->uc_link == NULL)
exit(0);
setcontext((const ucontext_t *)ucp->uc_link);
/* should never get here */
abort();
/* NOTREACHED */
}
__weak_reference(__signalcontext, signalcontext);
int
__signalcontext(ucontext_t *ucp, int sig, __sighandler_t *func)
{
uint64_t *args, *bsp;
siginfo_t *sig_si;
ucontext_t *sig_uc;
uint64_t sp;
/* Bail out if we don't have a valid ucontext pointer. */
if (ucp == NULL)
abort();
/*
* Build a signal frame and copy the arguments of signal handler
* 'func' onto the (memory) stack. We only need 3 arguments, but
* we create room for 4 so that we are 16-byte aligned.
*/
sp = (ucp->uc_mcontext.mc_special.sp - sizeof(ucontext_t)) & ~15UL;
sig_uc = (ucontext_t*)sp;
bcopy(ucp, sig_uc, sizeof(*sig_uc));
sp = (sp - sizeof(siginfo_t)) & ~15UL;
sig_si = (siginfo_t*)sp;
bzero(sig_si, sizeof(*sig_si));
sig_si->si_signo = sig;
sp -= 4 * sizeof(uint64_t);
args = (uint64_t*)sp;
args[0] = sig;
args[1] = (intptr_t)sig_si;
args[2] = (intptr_t)sig_uc;
/*
* Push (spill) the arguments of the context wrapper onto the register
* stack. They get loaded by the RSE on a context switch.
*/
bsp = (uint64_t*)ucp->uc_mcontext.mc_special.bspstore;
bsp = spill(bsp, (intptr_t)ucp);
bsp = spill(bsp, (intptr_t)func);
bsp = spill(bsp, (intptr_t)args);
/*
* Setup the ucontext of the signal handler.
*/
memset(&ucp->uc_mcontext, 0, sizeof(ucp->uc_mcontext));
ucp->uc_link = sig_uc;
sigdelset(&ucp->uc_sigmask, sig);
ucp->uc_mcontext.mc_special.sp = (intptr_t)args - 16;
ucp->uc_mcontext.mc_special.bspstore = (intptr_t)bsp;
ucp->uc_mcontext.mc_special.pfs = (3 << 7) | 3;
ucp->uc_mcontext.mc_special.rsc = 0xf;
ucp->uc_mcontext.mc_special.rp = ((struct fdesc*)ctx_wrapper)->ip;
ucp->uc_mcontext.mc_special.gp = ((struct fdesc*)ctx_wrapper)->gp;
ucp->uc_mcontext.mc_special.fpsr = IA64_FPSR_DEFAULT;
return (0);
}
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