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/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2004 Marcel Moolenaar, Peter Grehan
* 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/param.h>
#include <sys/ucontext.h>
#include <signal.h>
#include <stdlib.h>
#include <strings.h>
typedef void (*handler_t)(uint32_t, uint32_t, uint32_t);
/* Prototypes */
static void ctx_wrapper(ucontext_t *ucp, handler_t func, uint32_t sig,
uint32_t sig_si, uint32_t sig_uc);
__weak_reference(__signalcontext, signalcontext);
int
__signalcontext(ucontext_t *ucp, int sig, __sighandler_t *func)
{
siginfo_t *sig_si;
ucontext_t *sig_uc;
uintptr_t sp;
/* Bail out if we don't have a valid ucontext pointer. */
if (ucp == NULL)
abort();
/*
* Build a 16-byte-aligned signal frame
*/
sp = (ucp->uc_mcontext.mc_gpr[1] - 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;
/*
* Subtract 48 bytes from stack to allow for frameptr
*/
sp -= 6*sizeof(uint64_t);
sp &= ~15UL;
/*
* Setup the ucontext of the signal handler.
*/
bzero(&ucp->uc_mcontext, sizeof(ucp->uc_mcontext));
ucp->uc_link = sig_uc;
sigdelset(&ucp->uc_sigmask, sig);
ucp->uc_mcontext.mc_vers = _MC_VERSION;
ucp->uc_mcontext.mc_len = sizeof(struct __mcontext);
ucp->uc_mcontext.mc_srr0 = (uint64_t) ctx_wrapper;
ucp->uc_mcontext.mc_gpr[1] = (uint64_t) sp;
ucp->uc_mcontext.mc_gpr[3] = (uint64_t) func;
ucp->uc_mcontext.mc_gpr[4] = (uint64_t) sig;
ucp->uc_mcontext.mc_gpr[5] = (uint64_t) sig_si;
ucp->uc_mcontext.mc_gpr[6] = (uint64_t) sig_uc;
return (0);
}
static void
ctx_wrapper(ucontext_t *ucp, handler_t func, uint32_t sig, uint32_t sig_si,
uint32_t sig_uc)
{
(*func)(sig, sig_si, sig_uc);
if (ucp->uc_link == NULL)
exit(0);
setcontext((const ucontext_t *)ucp->uc_link);
/* should never get here */
abort();
/* NOTREACHED */
}
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