1 /* 2 * Emulation of Linux signal handling 3 * 4 * Copyright (c) 2003 Fabrice Bellard 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License as published by 8 * the Free Software Foundation; either version 2 of the License, or 9 * (at your option) any later version. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program; if not, write to the Free Software 18 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 19 */ 20 #include <stdlib.h> 21 #include <stdio.h> 22 #include <stdarg.h> 23 #include <signal.h> 24 #include <sys/ucontext.h> 25 26 /* Algorithm strongly inspired from em86 : we queue the signals so 27 that we can handle them at precise points in the emulated code. */ 28 29 struct emulated_sigaction { 30 struct target_sigaction sa; 31 int nb_pending; 32 struct target_siginfo info; 33 }; 34 35 struct emulated_sigaction sigact_table[NSIG]; 36 int signal_pending; 37 38 static inline int host_to_target_signal(int sig) 39 { 40 return sig; 41 } 42 43 static inline int target_to_host_signal(int sig) 44 { 45 return sig; 46 } 47 48 void signal_init(void) 49 { 50 struct sigaction act; 51 int i; 52 53 /* set all host signal handlers */ 54 sigemptyset(&act.sa_mask); 55 act.sa_flags = SA_SIGINFO; 56 act.sa_sigaction = host_signal_handler; 57 for(i = 1; i < NSIG; i++) { 58 sigaction(i, &sa, NULL); 59 } 60 61 memset(sigact_table, 0, sizeof(sigact_table)); 62 } 63 64 static void host_signal_handler(int host_signum, siginfo_t *info, 65 void *puc) 66 { 67 struct ucontext *uc = puc; 68 int signum; 69 /* get target signal number */ 70 signum = host_to_target(host_signum); 71 if (signum >= TARGET_NSIG) 72 return; 73 /* we save the old mask */ 74 75 76 } 77 78 79 void process_pending_signals(void) 80 { 81 int signum; 82 target_ulong _sa_handler; 83 84 struct emulated_sigaction *esig; 85 86 if (!signal_pending) 87 return; 88 89 esig = sigact_table; 90 for(signum = 1; signum < TARGET_NSIG; signum++) { 91 if (esig->nb_pending != 0) 92 goto handle_signal; 93 esig++; 94 } 95 /* if no signal is pending, just return */ 96 signal_pending = 0; 97 return; 98 handle_signal: 99 _sa_handler = esig->sa._sa_handler; 100 if (_sa_handler == TARGET_SIG_DFL) { 101 /* default handling 102 } 103 104 105 } 106