freebsd-dev/usr.bin/doscmd/signal.c

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/*
* Copyright (c) 1992, 1993, 1996
* Berkeley Software Design, Inc. 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Berkeley Software
* Design, Inc.
*
* THIS SOFTWARE IS PROVIDED BY Berkeley Software Design, Inc. ``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 Berkeley Software Design, Inc. 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.
*
* BSDI signal.c,v 2.2 1996/04/08 19:33:06 bostic Exp
*
1999-08-28 01:08:13 +00:00
* $FreeBSD$
*/
#include "doscmd.h"
static void (*handler[NSIG])(struct sigframe *);
static char signal_stack[16 * 1024];
#define PSS(w) { char s; printf(w " @ %08x\n", (signal_stack + sizeof signal_stack) - &s); }
struct sigframe *saved_sigframe;
regcontext_t *saved_regcontext;
int saved_valid = 0;
static void
sanity_check(struct sigframe *sf)
{
#if 0
static sigset_t oset;
int i;
for (i = 1; i < 32; ++i) {
if (sigismember(&sf->sf_sc.sc_mask, i) != sigismember(&oset, i))
fprintf(debugf, "Signal %s %s being blocked\n",
sys_signame[i],
sigismember(&sf->sf_sc.sc_mask, i) ? "now" : "no longer");
}
oset = sf->sf_sc.sc_mask;
#endif
if (dead)
fatal("attempting to return to vm86 while dead");
}
#if defined(__FreeBSD__) || defined(USE_VM86)
static void
generichandler(struct sigframe sf)
{
if (sf.sf_uc.uc_mcontext.mc_eflags & PSL_VM) {
saved_sigframe = &sf;
saved_regcontext = (regcontext_t *)&(sf.sf_uc.uc_mcontext);
saved_valid = 1;
if (handler[sf.sf_signum])
(*handler[sf.sf_signum])(&sf);
saved_valid = 0;
sanity_check(&sf);
} else {
if (handler[sf.sf_signum])
(*handler[sf.sf_signum])(&sf);
}
}
#else
#error BSD/OS sigframe/trapframe kernel interface not currently supported.
#endif
void
setsignal(int s, void (*h)(struct sigframe *))
{
static int first = 1;
struct sigaction sa;
sigset_t set;
if (first) {
struct sigaltstack sstack;
sstack.ss_sp = signal_stack;
sstack.ss_size = sizeof signal_stack;
sstack.ss_flags = 0;
sigaltstack (&sstack, NULL);
first = 0;
}
if (s >= 0 && s < NSIG) {
handler[s] = h;
sa.sa_handler = (__sighandler_t *)generichandler;
sigemptyset(&sa.sa_mask);
sigaddset(&sa.sa_mask, SIGIO);
sigaddset(&sa.sa_mask, SIGALRM);
sa.sa_flags = SA_ONSTACK;
sigaction(s, &sa, NULL);
sigaddset(&set, s);
sigprocmask(SIG_UNBLOCK, &set, 0);
}
}