1 /* 2 * Emulation of BSD signals 3 * 4 * Copyright (c) 2003 - 2008 Fabrice Bellard 5 * Copyright (c) 2013 Stacey Son 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License as published by 9 * the Free Software Foundation; either version 2 of the License, or 10 * (at your option) any later version. 11 * 12 * This program is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 * GNU General Public License for more details. 16 * 17 * You should have received a copy of the GNU General Public License 18 * along with this program; if not, see <http://www.gnu.org/licenses/>. 19 */ 20 21 #include "qemu/osdep.h" 22 #include "qemu.h" 23 #include "signal-common.h" 24 #include "hw/core/tcg-cpu-ops.h" 25 #include "host-signal.h" 26 27 /* 28 * Stubbed out routines until we merge signal support from bsd-user 29 * fork. 30 */ 31 32 static struct target_sigaction sigact_table[TARGET_NSIG]; 33 static void host_signal_handler(int host_sig, siginfo_t *info, void *puc); 34 35 /* 36 * The BSD ABIs use the same singal numbers across all the CPU architectures, so 37 * (unlike Linux) these functions are just the identity mapping. This might not 38 * be true for XyzBSD running on AbcBSD, which doesn't currently work. 39 */ 40 int host_to_target_signal(int sig) 41 { 42 return sig; 43 } 44 45 int target_to_host_signal(int sig) 46 { 47 return sig; 48 } 49 50 /* 51 * Queue a signal so that it will be send to the virtual CPU as soon as 52 * possible. 53 */ 54 void queue_signal(CPUArchState *env, int sig, int si_type, 55 target_siginfo_t *info) 56 { 57 qemu_log_mask(LOG_UNIMP, "No signal queueing, dropping signal %d\n", sig); 58 } 59 60 static int fatal_signal(int sig) 61 { 62 63 switch (sig) { 64 case TARGET_SIGCHLD: 65 case TARGET_SIGURG: 66 case TARGET_SIGWINCH: 67 case TARGET_SIGINFO: 68 /* Ignored by default. */ 69 return 0; 70 case TARGET_SIGCONT: 71 case TARGET_SIGSTOP: 72 case TARGET_SIGTSTP: 73 case TARGET_SIGTTIN: 74 case TARGET_SIGTTOU: 75 /* Job control signals. */ 76 return 0; 77 default: 78 return 1; 79 } 80 } 81 82 /* 83 * Force a synchronously taken QEMU_SI_FAULT signal. For QEMU the 84 * 'force' part is handled in process_pending_signals(). 85 */ 86 void force_sig_fault(int sig, int code, abi_ulong addr) 87 { 88 CPUState *cpu = thread_cpu; 89 CPUArchState *env = cpu->env_ptr; 90 target_siginfo_t info = {}; 91 92 info.si_signo = sig; 93 info.si_errno = 0; 94 info.si_code = code; 95 info.si_addr = addr; 96 queue_signal(env, sig, QEMU_SI_FAULT, &info); 97 } 98 99 static void host_signal_handler(int host_sig, siginfo_t *info, void *puc) 100 { 101 } 102 103 void signal_init(void) 104 { 105 TaskState *ts = (TaskState *)thread_cpu->opaque; 106 struct sigaction act; 107 struct sigaction oact; 108 int i; 109 int host_sig; 110 111 /* Set the signal mask from the host mask. */ 112 sigprocmask(0, 0, &ts->signal_mask); 113 114 sigfillset(&act.sa_mask); 115 act.sa_sigaction = host_signal_handler; 116 act.sa_flags = SA_SIGINFO; 117 118 for (i = 1; i <= TARGET_NSIG; i++) { 119 #ifdef CONFIG_GPROF 120 if (i == TARGET_SIGPROF) { 121 continue; 122 } 123 #endif 124 host_sig = target_to_host_signal(i); 125 sigaction(host_sig, NULL, &oact); 126 if (oact.sa_sigaction == (void *)SIG_IGN) { 127 sigact_table[i - 1]._sa_handler = TARGET_SIG_IGN; 128 } else if (oact.sa_sigaction == (void *)SIG_DFL) { 129 sigact_table[i - 1]._sa_handler = TARGET_SIG_DFL; 130 } 131 /* 132 * If there's already a handler installed then something has 133 * gone horribly wrong, so don't even try to handle that case. 134 * Install some handlers for our own use. We need at least 135 * SIGSEGV and SIGBUS, to detect exceptions. We can not just 136 * trap all signals because it affects syscall interrupt 137 * behavior. But do trap all default-fatal signals. 138 */ 139 if (fatal_signal(i)) { 140 sigaction(host_sig, &act, NULL); 141 } 142 } 143 } 144 145 void process_pending_signals(CPUArchState *cpu_env) 146 { 147 } 148 149 void cpu_loop_exit_sigsegv(CPUState *cpu, target_ulong addr, 150 MMUAccessType access_type, bool maperr, uintptr_t ra) 151 { 152 const struct TCGCPUOps *tcg_ops = CPU_GET_CLASS(cpu)->tcg_ops; 153 154 if (tcg_ops->record_sigsegv) { 155 tcg_ops->record_sigsegv(cpu, addr, access_type, maperr, ra); 156 } 157 158 force_sig_fault(TARGET_SIGSEGV, 159 maperr ? TARGET_SEGV_MAPERR : TARGET_SEGV_ACCERR, 160 addr); 161 cpu->exception_index = EXCP_INTERRUPT; 162 cpu_loop_exit_restore(cpu, ra); 163 } 164 165 void cpu_loop_exit_sigbus(CPUState *cpu, target_ulong addr, 166 MMUAccessType access_type, uintptr_t ra) 167 { 168 const struct TCGCPUOps *tcg_ops = CPU_GET_CLASS(cpu)->tcg_ops; 169 170 if (tcg_ops->record_sigbus) { 171 tcg_ops->record_sigbus(cpu, addr, access_type, ra); 172 } 173 174 force_sig_fault(TARGET_SIGBUS, TARGET_BUS_ADRALN, addr); 175 cpu->exception_index = EXCP_INTERRUPT; 176 cpu_loop_exit_restore(cpu, ra); 177 } 178