1 /* 2 * Emulation of Linux signals 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, see <http://www.gnu.org/licenses/>. 18 */ 19 #include "qemu/osdep.h" 20 #include "qemu.h" 21 #include "signal-common.h" 22 #include "linux-user/trace.h" 23 24 #define MCONTEXT_VERSION 2 25 26 struct target_sigcontext { 27 int version; 28 unsigned long gregs[32]; 29 }; 30 31 struct target_ucontext { 32 abi_ulong tuc_flags; 33 abi_ulong tuc_link; 34 target_stack_t tuc_stack; 35 struct target_sigcontext tuc_mcontext; 36 target_sigset_t tuc_sigmask; /* mask last for extensibility */ 37 }; 38 39 struct target_rt_sigframe { 40 struct target_siginfo info; 41 struct target_ucontext uc; 42 }; 43 44 static int rt_setup_ucontext(struct target_ucontext *uc, CPUNios2State *env) 45 { 46 unsigned long *gregs = uc->tuc_mcontext.gregs; 47 48 __put_user(MCONTEXT_VERSION, &uc->tuc_mcontext.version); 49 __put_user(env->regs[1], &gregs[0]); 50 __put_user(env->regs[2], &gregs[1]); 51 __put_user(env->regs[3], &gregs[2]); 52 __put_user(env->regs[4], &gregs[3]); 53 __put_user(env->regs[5], &gregs[4]); 54 __put_user(env->regs[6], &gregs[5]); 55 __put_user(env->regs[7], &gregs[6]); 56 __put_user(env->regs[8], &gregs[7]); 57 __put_user(env->regs[9], &gregs[8]); 58 __put_user(env->regs[10], &gregs[9]); 59 __put_user(env->regs[11], &gregs[10]); 60 __put_user(env->regs[12], &gregs[11]); 61 __put_user(env->regs[13], &gregs[12]); 62 __put_user(env->regs[14], &gregs[13]); 63 __put_user(env->regs[15], &gregs[14]); 64 __put_user(env->regs[16], &gregs[15]); 65 __put_user(env->regs[17], &gregs[16]); 66 __put_user(env->regs[18], &gregs[17]); 67 __put_user(env->regs[19], &gregs[18]); 68 __put_user(env->regs[20], &gregs[19]); 69 __put_user(env->regs[21], &gregs[20]); 70 __put_user(env->regs[22], &gregs[21]); 71 __put_user(env->regs[23], &gregs[22]); 72 __put_user(env->regs[R_RA], &gregs[23]); 73 __put_user(env->regs[R_FP], &gregs[24]); 74 __put_user(env->regs[R_GP], &gregs[25]); 75 __put_user(env->regs[R_EA], &gregs[27]); 76 __put_user(env->regs[R_SP], &gregs[28]); 77 78 return 0; 79 } 80 81 static int rt_restore_ucontext(CPUNios2State *env, struct target_ucontext *uc, 82 int *pr2) 83 { 84 int temp; 85 unsigned long *gregs = uc->tuc_mcontext.gregs; 86 87 /* Always make any pending restarted system calls return -EINTR */ 88 /* current->restart_block.fn = do_no_restart_syscall; */ 89 90 __get_user(temp, &uc->tuc_mcontext.version); 91 if (temp != MCONTEXT_VERSION) { 92 return 1; 93 } 94 95 /* restore passed registers */ 96 __get_user(env->regs[1], &gregs[0]); 97 __get_user(env->regs[2], &gregs[1]); 98 __get_user(env->regs[3], &gregs[2]); 99 __get_user(env->regs[4], &gregs[3]); 100 __get_user(env->regs[5], &gregs[4]); 101 __get_user(env->regs[6], &gregs[5]); 102 __get_user(env->regs[7], &gregs[6]); 103 __get_user(env->regs[8], &gregs[7]); 104 __get_user(env->regs[9], &gregs[8]); 105 __get_user(env->regs[10], &gregs[9]); 106 __get_user(env->regs[11], &gregs[10]); 107 __get_user(env->regs[12], &gregs[11]); 108 __get_user(env->regs[13], &gregs[12]); 109 __get_user(env->regs[14], &gregs[13]); 110 __get_user(env->regs[15], &gregs[14]); 111 __get_user(env->regs[16], &gregs[15]); 112 __get_user(env->regs[17], &gregs[16]); 113 __get_user(env->regs[18], &gregs[17]); 114 __get_user(env->regs[19], &gregs[18]); 115 __get_user(env->regs[20], &gregs[19]); 116 __get_user(env->regs[21], &gregs[20]); 117 __get_user(env->regs[22], &gregs[21]); 118 __get_user(env->regs[23], &gregs[22]); 119 /* gregs[23] is handled below */ 120 /* Verify, should this be settable */ 121 __get_user(env->regs[R_FP], &gregs[24]); 122 /* Verify, should this be settable */ 123 __get_user(env->regs[R_GP], &gregs[25]); 124 /* Not really necessary no user settable bits */ 125 __get_user(temp, &gregs[26]); 126 __get_user(env->regs[R_EA], &gregs[27]); 127 128 __get_user(env->regs[R_RA], &gregs[23]); 129 __get_user(env->regs[R_SP], &gregs[28]); 130 131 target_restore_altstack(&uc->tuc_stack, env); 132 133 *pr2 = env->regs[2]; 134 return 0; 135 } 136 137 static void *get_sigframe(struct target_sigaction *ka, CPUNios2State *env, 138 size_t frame_size) 139 { 140 unsigned long usp; 141 142 /* This is the X/Open sanctioned signal stack switching. */ 143 usp = target_sigsp(get_sp_from_cpustate(env), ka); 144 145 /* Verify, is it 32 or 64 bit aligned */ 146 return (void *)((usp - frame_size) & -8UL); 147 } 148 149 void setup_rt_frame(int sig, struct target_sigaction *ka, 150 target_siginfo_t *info, 151 target_sigset_t *set, 152 CPUNios2State *env) 153 { 154 struct target_rt_sigframe *frame; 155 int i, err = 0; 156 157 frame = get_sigframe(ka, env, sizeof(*frame)); 158 159 if (ka->sa_flags & SA_SIGINFO) { 160 tswap_siginfo(&frame->info, info); 161 } 162 163 /* Create the ucontext. */ 164 __put_user(0, &frame->uc.tuc_flags); 165 __put_user(0, &frame->uc.tuc_link); 166 target_save_altstack(&frame->uc.tuc_stack, env); 167 err |= rt_setup_ucontext(&frame->uc, env); 168 for (i = 0; i < TARGET_NSIG_WORDS; i++) { 169 __put_user((abi_ulong)set->sig[i], 170 (abi_ulong *)&frame->uc.tuc_sigmask.sig[i]); 171 } 172 173 if (err) { 174 goto give_sigsegv; 175 } 176 177 /* Set up to return from userspace; jump to fixed address sigreturn 178 trampoline on kuser page. */ 179 env->regs[R_RA] = (unsigned long) (0x1044); 180 181 /* Set up registers for signal handler */ 182 env->regs[R_SP] = (unsigned long) frame; 183 env->regs[4] = (unsigned long) sig; 184 env->regs[5] = (unsigned long) &frame->info; 185 env->regs[6] = (unsigned long) &frame->uc; 186 env->regs[R_EA] = (unsigned long) ka->_sa_handler; 187 return; 188 189 give_sigsegv: 190 if (sig == TARGET_SIGSEGV) { 191 ka->_sa_handler = TARGET_SIG_DFL; 192 } 193 force_sigsegv(sig); 194 return; 195 } 196 197 long do_sigreturn(CPUNios2State *env) 198 { 199 trace_user_do_sigreturn(env, 0); 200 qemu_log_mask(LOG_UNIMP, "do_sigreturn: not implemented\n"); 201 return -TARGET_ENOSYS; 202 } 203 204 long do_rt_sigreturn(CPUNios2State *env) 205 { 206 /* Verify, can we follow the stack back */ 207 abi_ulong frame_addr = env->regs[R_SP]; 208 struct target_rt_sigframe *frame; 209 sigset_t set; 210 int rval; 211 212 if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) { 213 goto badframe; 214 } 215 216 target_to_host_sigset(&set, &frame->uc.tuc_sigmask); 217 do_sigprocmask(SIG_SETMASK, &set, NULL); 218 219 if (rt_restore_ucontext(env, &frame->uc, &rval)) { 220 goto badframe; 221 } 222 223 unlock_user_struct(frame, frame_addr, 0); 224 return rval; 225 226 badframe: 227 unlock_user_struct(frame, frame_addr, 0); 228 force_sig(TARGET_SIGSEGV); 229 return 0; 230 } 231