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 26 /* 27 * Stubbed out routines until we merge signal support from bsd-user 28 * fork. 29 */ 30 31 static struct target_sigaction sigact_table[TARGET_NSIG]; 32 static void host_signal_handler(int host_sig, siginfo_t *info, void *puc); 33 34 /* 35 * The BSD ABIs use the same singal numbers across all the CPU architectures, so 36 * (unlike Linux) these functions are just the identity mapping. This might not 37 * be true for XyzBSD running on AbcBSD, which doesn't currently work. 38 */ 39 int host_to_target_signal(int sig) 40 { 41 return sig; 42 } 43 44 int target_to_host_signal(int sig) 45 { 46 return sig; 47 } 48 49 /* 50 * Queue a signal so that it will be send to the virtual CPU as soon as 51 * possible. 52 */ 53 void queue_signal(CPUArchState *env, int sig, int si_type, 54 target_siginfo_t *info) 55 { 56 qemu_log_mask(LOG_UNIMP, "No signal queueing, dropping signal %d\n", sig); 57 } 58 59 static int fatal_signal(int sig) 60 { 61 62 switch (sig) { 63 case TARGET_SIGCHLD: 64 case TARGET_SIGURG: 65 case TARGET_SIGWINCH: 66 case TARGET_SIGINFO: 67 /* Ignored by default. */ 68 return 0; 69 case TARGET_SIGCONT: 70 case TARGET_SIGSTOP: 71 case TARGET_SIGTSTP: 72 case TARGET_SIGTTIN: 73 case TARGET_SIGTTOU: 74 /* Job control signals. */ 75 return 0; 76 default: 77 return 1; 78 } 79 } 80 81 /* 82 * Force a synchronously taken QEMU_SI_FAULT signal. For QEMU the 83 * 'force' part is handled in process_pending_signals(). 84 */ 85 void force_sig_fault(int sig, int code, abi_ulong addr) 86 { 87 CPUState *cpu = thread_cpu; 88 CPUArchState *env = cpu->env_ptr; 89 target_siginfo_t info = {}; 90 91 info.si_signo = sig; 92 info.si_errno = 0; 93 info.si_code = code; 94 info.si_addr = addr; 95 queue_signal(env, sig, QEMU_SI_FAULT, &info); 96 } 97 98 static void host_signal_handler(int host_sig, siginfo_t *info, void *puc) 99 { 100 } 101 102 void signal_init(void) 103 { 104 TaskState *ts = (TaskState *)thread_cpu->opaque; 105 struct sigaction act; 106 struct sigaction oact; 107 int i; 108 int host_sig; 109 110 /* Set the signal mask from the host mask. */ 111 sigprocmask(0, 0, &ts->signal_mask); 112 113 sigfillset(&act.sa_mask); 114 act.sa_sigaction = host_signal_handler; 115 act.sa_flags = SA_SIGINFO; 116 117 for (i = 1; i <= TARGET_NSIG; i++) { 118 #ifdef CONFIG_GPROF 119 if (i == TARGET_SIGPROF) { 120 continue; 121 } 122 #endif 123 host_sig = target_to_host_signal(i); 124 sigaction(host_sig, NULL, &oact); 125 if (oact.sa_sigaction == (void *)SIG_IGN) { 126 sigact_table[i - 1]._sa_handler = TARGET_SIG_IGN; 127 } else if (oact.sa_sigaction == (void *)SIG_DFL) { 128 sigact_table[i - 1]._sa_handler = TARGET_SIG_DFL; 129 } 130 /* 131 * If there's already a handler installed then something has 132 * gone horribly wrong, so don't even try to handle that case. 133 * Install some handlers for our own use. We need at least 134 * SIGSEGV and SIGBUS, to detect exceptions. We can not just 135 * trap all signals because it affects syscall interrupt 136 * behavior. But do trap all default-fatal signals. 137 */ 138 if (fatal_signal(i)) { 139 sigaction(host_sig, &act, NULL); 140 } 141 } 142 } 143 144 void process_pending_signals(CPUArchState *cpu_env) 145 { 146 } 147 148 void cpu_loop_exit_sigsegv(CPUState *cpu, target_ulong addr, 149 MMUAccessType access_type, bool maperr, uintptr_t ra) 150 { 151 const struct TCGCPUOps *tcg_ops = CPU_GET_CLASS(cpu)->tcg_ops; 152 153 if (tcg_ops->record_sigsegv) { 154 tcg_ops->record_sigsegv(cpu, addr, access_type, maperr, ra); 155 } 156 157 force_sig_fault(TARGET_SIGSEGV, 158 maperr ? TARGET_SEGV_MAPERR : TARGET_SEGV_ACCERR, 159 addr); 160 cpu->exception_index = EXCP_INTERRUPT; 161 cpu_loop_exit_restore(cpu, ra); 162 } 163 164 void cpu_loop_exit_sigbus(CPUState *cpu, target_ulong addr, 165 MMUAccessType access_type, uintptr_t ra) 166 { 167 const struct TCGCPUOps *tcg_ops = CPU_GET_CLASS(cpu)->tcg_ops; 168 169 if (tcg_ops->record_sigbus) { 170 tcg_ops->record_sigbus(cpu, addr, access_type, ra); 171 } 172 173 force_sig_fault(TARGET_SIGBUS, TARGET_BUS_ADRALN, addr); 174 cpu->exception_index = EXCP_INTERRUPT; 175 cpu_loop_exit_restore(cpu, ra); 176 } 177