signal.c (7230B)
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 "user-internals.h" 22#include "signal-common.h" 23#include "linux-user/trace.h" 24 25#define MCONTEXT_VERSION 2 26 27struct target_sigcontext { 28 int version; 29 unsigned long gregs[32]; 30}; 31 32struct target_ucontext { 33 abi_ulong tuc_flags; 34 abi_ulong tuc_link; 35 target_stack_t tuc_stack; 36 struct target_sigcontext tuc_mcontext; 37 target_sigset_t tuc_sigmask; /* mask last for extensibility */ 38}; 39 40struct target_rt_sigframe { 41 struct target_siginfo info; 42 struct target_ucontext uc; 43}; 44 45static int rt_setup_ucontext(struct target_ucontext *uc, CPUNios2State *env) 46{ 47 unsigned long *gregs = uc->tuc_mcontext.gregs; 48 49 __put_user(MCONTEXT_VERSION, &uc->tuc_mcontext.version); 50 __put_user(env->regs[1], &gregs[0]); 51 __put_user(env->regs[2], &gregs[1]); 52 __put_user(env->regs[3], &gregs[2]); 53 __put_user(env->regs[4], &gregs[3]); 54 __put_user(env->regs[5], &gregs[4]); 55 __put_user(env->regs[6], &gregs[5]); 56 __put_user(env->regs[7], &gregs[6]); 57 __put_user(env->regs[8], &gregs[7]); 58 __put_user(env->regs[9], &gregs[8]); 59 __put_user(env->regs[10], &gregs[9]); 60 __put_user(env->regs[11], &gregs[10]); 61 __put_user(env->regs[12], &gregs[11]); 62 __put_user(env->regs[13], &gregs[12]); 63 __put_user(env->regs[14], &gregs[13]); 64 __put_user(env->regs[15], &gregs[14]); 65 __put_user(env->regs[16], &gregs[15]); 66 __put_user(env->regs[17], &gregs[16]); 67 __put_user(env->regs[18], &gregs[17]); 68 __put_user(env->regs[19], &gregs[18]); 69 __put_user(env->regs[20], &gregs[19]); 70 __put_user(env->regs[21], &gregs[20]); 71 __put_user(env->regs[22], &gregs[21]); 72 __put_user(env->regs[23], &gregs[22]); 73 __put_user(env->regs[R_RA], &gregs[23]); 74 __put_user(env->regs[R_FP], &gregs[24]); 75 __put_user(env->regs[R_GP], &gregs[25]); 76 __put_user(env->regs[R_EA], &gregs[27]); 77 __put_user(env->regs[R_SP], &gregs[28]); 78 79 return 0; 80} 81 82static int rt_restore_ucontext(CPUNios2State *env, struct target_ucontext *uc, 83 int *pr2) 84{ 85 int temp; 86 unsigned long *gregs = uc->tuc_mcontext.gregs; 87 88 /* Always make any pending restarted system calls return -EINTR */ 89 /* current->restart_block.fn = do_no_restart_syscall; */ 90 91 __get_user(temp, &uc->tuc_mcontext.version); 92 if (temp != MCONTEXT_VERSION) { 93 return 1; 94 } 95 96 /* restore passed registers */ 97 __get_user(env->regs[1], &gregs[0]); 98 __get_user(env->regs[2], &gregs[1]); 99 __get_user(env->regs[3], &gregs[2]); 100 __get_user(env->regs[4], &gregs[3]); 101 __get_user(env->regs[5], &gregs[4]); 102 __get_user(env->regs[6], &gregs[5]); 103 __get_user(env->regs[7], &gregs[6]); 104 __get_user(env->regs[8], &gregs[7]); 105 __get_user(env->regs[9], &gregs[8]); 106 __get_user(env->regs[10], &gregs[9]); 107 __get_user(env->regs[11], &gregs[10]); 108 __get_user(env->regs[12], &gregs[11]); 109 __get_user(env->regs[13], &gregs[12]); 110 __get_user(env->regs[14], &gregs[13]); 111 __get_user(env->regs[15], &gregs[14]); 112 __get_user(env->regs[16], &gregs[15]); 113 __get_user(env->regs[17], &gregs[16]); 114 __get_user(env->regs[18], &gregs[17]); 115 __get_user(env->regs[19], &gregs[18]); 116 __get_user(env->regs[20], &gregs[19]); 117 __get_user(env->regs[21], &gregs[20]); 118 __get_user(env->regs[22], &gregs[21]); 119 __get_user(env->regs[23], &gregs[22]); 120 /* gregs[23] is handled below */ 121 /* Verify, should this be settable */ 122 __get_user(env->regs[R_FP], &gregs[24]); 123 /* Verify, should this be settable */ 124 __get_user(env->regs[R_GP], &gregs[25]); 125 /* Not really necessary no user settable bits */ 126 __get_user(temp, &gregs[26]); 127 __get_user(env->regs[R_EA], &gregs[27]); 128 129 __get_user(env->regs[R_RA], &gregs[23]); 130 __get_user(env->regs[R_SP], &gregs[28]); 131 132 target_restore_altstack(&uc->tuc_stack, env); 133 134 *pr2 = env->regs[2]; 135 return 0; 136} 137 138static void *get_sigframe(struct target_sigaction *ka, CPUNios2State *env, 139 size_t frame_size) 140{ 141 unsigned long usp; 142 143 /* This is the X/Open sanctioned signal stack switching. */ 144 usp = target_sigsp(get_sp_from_cpustate(env), ka); 145 146 /* Verify, is it 32 or 64 bit aligned */ 147 return (void *)((usp - frame_size) & -8UL); 148} 149 150void setup_rt_frame(int sig, struct target_sigaction *ka, 151 target_siginfo_t *info, 152 target_sigset_t *set, 153 CPUNios2State *env) 154{ 155 struct target_rt_sigframe *frame; 156 int i, err = 0; 157 158 frame = get_sigframe(ka, env, sizeof(*frame)); 159 160 if (ka->sa_flags & SA_SIGINFO) { 161 tswap_siginfo(&frame->info, info); 162 } 163 164 /* Create the ucontext. */ 165 __put_user(0, &frame->uc.tuc_flags); 166 __put_user(0, &frame->uc.tuc_link); 167 target_save_altstack(&frame->uc.tuc_stack, env); 168 err |= rt_setup_ucontext(&frame->uc, env); 169 for (i = 0; i < TARGET_NSIG_WORDS; i++) { 170 __put_user((abi_ulong)set->sig[i], 171 (abi_ulong *)&frame->uc.tuc_sigmask.sig[i]); 172 } 173 174 if (err) { 175 goto give_sigsegv; 176 } 177 178 /* Set up to return from userspace; jump to fixed address sigreturn 179 trampoline on kuser page. */ 180 env->regs[R_RA] = (unsigned long) (0x1044); 181 182 /* Set up registers for signal handler */ 183 env->regs[R_SP] = (unsigned long) frame; 184 env->regs[4] = (unsigned long) sig; 185 env->regs[5] = (unsigned long) &frame->info; 186 env->regs[6] = (unsigned long) &frame->uc; 187 env->regs[R_EA] = (unsigned long) ka->_sa_handler; 188 return; 189 190give_sigsegv: 191 if (sig == TARGET_SIGSEGV) { 192 ka->_sa_handler = TARGET_SIG_DFL; 193 } 194 force_sigsegv(sig); 195 return; 196} 197 198long do_sigreturn(CPUNios2State *env) 199{ 200 trace_user_do_sigreturn(env, 0); 201 qemu_log_mask(LOG_UNIMP, "do_sigreturn: not implemented\n"); 202 return -TARGET_ENOSYS; 203} 204 205long do_rt_sigreturn(CPUNios2State *env) 206{ 207 /* Verify, can we follow the stack back */ 208 abi_ulong frame_addr = env->regs[R_SP]; 209 struct target_rt_sigframe *frame; 210 sigset_t set; 211 int rval; 212 213 if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) { 214 goto badframe; 215 } 216 217 target_to_host_sigset(&set, &frame->uc.tuc_sigmask); 218 do_sigprocmask(SIG_SETMASK, &set, NULL); 219 220 if (rt_restore_ucontext(env, &frame->uc, &rval)) { 221 goto badframe; 222 } 223 224 unlock_user_struct(frame, frame_addr, 0); 225 return rval; 226 227badframe: 228 unlock_user_struct(frame, frame_addr, 0); 229 force_sig(TARGET_SIGSEGV); 230 return 0; 231}