qemu/linux-user/signal.c

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/*
* Emulation of Linux signal handling
*
* Copyright (c) 2003 Fabrice Bellard
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <stdlib.h>
#include <stdio.h>
#include <stdarg.h>
#include <signal.h>
#include <sys/ucontext.h>
/* Algorithm strongly inspired from em86 : we queue the signals so
that we can handle them at precise points in the emulated code. */
struct emulated_sigaction {
struct target_sigaction sa;
int nb_pending;
struct target_siginfo info;
};
struct emulated_sigaction sigact_table[NSIG];
int signal_pending;
static inline int host_to_target_signal(int sig)
{
return sig;
}
static inline int target_to_host_signal(int sig)
{
return sig;
}
void signal_init(void)
{
struct sigaction act;
int i;
/* set all host signal handlers */
sigemptyset(&act.sa_mask);
act.sa_flags = SA_SIGINFO;
act.sa_sigaction = host_signal_handler;
for(i = 1; i < NSIG; i++) {
sigaction(i, &sa, NULL);
}
memset(sigact_table, 0, sizeof(sigact_table));
}
static void host_signal_handler(int host_signum, siginfo_t *info,
void *puc)
{
struct ucontext *uc = puc;
int signum;
/* get target signal number */
signum = host_to_target(host_signum);
if (signum >= TARGET_NSIG)
return;
/* we save the old mask */
}
void process_pending_signals(void)
{
int signum;
target_ulong _sa_handler;
struct emulated_sigaction *esig;
if (!signal_pending)
return;
esig = sigact_table;
for(signum = 1; signum < TARGET_NSIG; signum++) {
if (esig->nb_pending != 0)
goto handle_signal;
esig++;
}
/* if no signal is pending, just return */
signal_pending = 0;
return;
handle_signal:
_sa_handler = esig->sa._sa_handler;
if (_sa_handler == TARGET_SIG_DFL) {
/* default handling
}
}