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 /* 26 * code and data structures from linux kernel: 27 * include/asm-sh/sigcontext.h 28 * arch/sh/kernel/signal.c 29 */ 30 31 struct target_sigcontext { 32 target_ulong oldmask; 33 34 /* CPU registers */ 35 target_ulong sc_gregs[16]; 36 target_ulong sc_pc; 37 target_ulong sc_pr; 38 target_ulong sc_sr; 39 target_ulong sc_gbr; 40 target_ulong sc_mach; 41 target_ulong sc_macl; 42 43 /* FPU registers */ 44 target_ulong sc_fpregs[16]; 45 target_ulong sc_xfpregs[16]; 46 unsigned int sc_fpscr; 47 unsigned int sc_fpul; 48 unsigned int sc_ownedfp; 49 }; 50 51 struct target_sigframe 52 { 53 struct target_sigcontext sc; 54 target_ulong extramask[TARGET_NSIG_WORDS-1]; 55 }; 56 57 58 struct target_ucontext { 59 target_ulong tuc_flags; 60 struct target_ucontext *tuc_link; 61 target_stack_t tuc_stack; 62 struct target_sigcontext tuc_mcontext; 63 target_sigset_t tuc_sigmask; /* mask last for extensibility */ 64 }; 65 66 struct target_rt_sigframe 67 { 68 struct target_siginfo info; 69 struct target_ucontext uc; 70 }; 71 72 73 #define MOVW(n) (0x9300|((n)-2)) /* Move mem word at PC+n to R3 */ 74 #define TRAP_NOARG 0xc310 /* Syscall w/no args (NR in R3) SH3/4 */ 75 76 static abi_ulong get_sigframe(struct target_sigaction *ka, 77 unsigned long sp, size_t frame_size) 78 { 79 sp = target_sigsp(sp, ka); 80 81 return (sp - frame_size) & -8ul; 82 } 83 84 /* 85 * Notice when we're in the middle of a gUSA region and reset. 86 * Note that this will only occur when #CF_PARALLEL is unset, as we 87 * will translate such sequences differently in a parallel context. 88 */ 89 static void unwind_gusa(CPUSH4State *regs) 90 { 91 /* If the stack pointer is sufficiently negative, and we haven't 92 completed the sequence, then reset to the entry to the region. */ 93 /* ??? The SH4 kernel checks for and address above 0xC0000000. 94 However, the page mappings in qemu linux-user aren't as restricted 95 and we wind up with the normal stack mapped above 0xF0000000. 96 That said, there is no reason why the kernel should be allowing 97 a gUSA region that spans 1GB. Use a tighter check here, for what 98 can actually be enabled by the immediate move. */ 99 if (regs->gregs[15] >= -128u && regs->pc < regs->gregs[0]) { 100 /* Reset the PC to before the gUSA region, as computed from 101 R0 = region end, SP = -(region size), plus one more for the 102 insn that actually initializes SP to the region size. */ 103 regs->pc = regs->gregs[0] + regs->gregs[15] - 2; 104 105 /* Reset the SP to the saved version in R1. */ 106 regs->gregs[15] = regs->gregs[1]; 107 } 108 } 109 110 static void setup_sigcontext(struct target_sigcontext *sc, 111 CPUSH4State *regs, unsigned long mask) 112 { 113 int i; 114 115 #define COPY(x) __put_user(regs->x, &sc->sc_##x) 116 COPY(gregs[0]); COPY(gregs[1]); 117 COPY(gregs[2]); COPY(gregs[3]); 118 COPY(gregs[4]); COPY(gregs[5]); 119 COPY(gregs[6]); COPY(gregs[7]); 120 COPY(gregs[8]); COPY(gregs[9]); 121 COPY(gregs[10]); COPY(gregs[11]); 122 COPY(gregs[12]); COPY(gregs[13]); 123 COPY(gregs[14]); COPY(gregs[15]); 124 COPY(gbr); COPY(mach); 125 COPY(macl); COPY(pr); 126 COPY(sr); COPY(pc); 127 #undef COPY 128 129 for (i=0; i<16; i++) { 130 __put_user(regs->fregs[i], &sc->sc_fpregs[i]); 131 } 132 __put_user(regs->fpscr, &sc->sc_fpscr); 133 __put_user(regs->fpul, &sc->sc_fpul); 134 135 /* non-iBCS2 extensions.. */ 136 __put_user(mask, &sc->oldmask); 137 } 138 139 static void restore_sigcontext(CPUSH4State *regs, struct target_sigcontext *sc) 140 { 141 int i; 142 143 #define COPY(x) __get_user(regs->x, &sc->sc_##x) 144 COPY(gregs[0]); COPY(gregs[1]); 145 COPY(gregs[2]); COPY(gregs[3]); 146 COPY(gregs[4]); COPY(gregs[5]); 147 COPY(gregs[6]); COPY(gregs[7]); 148 COPY(gregs[8]); COPY(gregs[9]); 149 COPY(gregs[10]); COPY(gregs[11]); 150 COPY(gregs[12]); COPY(gregs[13]); 151 COPY(gregs[14]); COPY(gregs[15]); 152 COPY(gbr); COPY(mach); 153 COPY(macl); COPY(pr); 154 COPY(sr); COPY(pc); 155 #undef COPY 156 157 for (i=0; i<16; i++) { 158 __get_user(regs->fregs[i], &sc->sc_fpregs[i]); 159 } 160 __get_user(regs->fpscr, &sc->sc_fpscr); 161 __get_user(regs->fpul, &sc->sc_fpul); 162 163 regs->tra = -1; /* disable syscall checks */ 164 regs->flags = 0; 165 } 166 167 void setup_frame(int sig, struct target_sigaction *ka, 168 target_sigset_t *set, CPUSH4State *regs) 169 { 170 struct target_sigframe *frame; 171 abi_ulong frame_addr; 172 int i; 173 174 unwind_gusa(regs); 175 176 frame_addr = get_sigframe(ka, regs->gregs[15], sizeof(*frame)); 177 trace_user_setup_frame(regs, frame_addr); 178 if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) { 179 goto give_sigsegv; 180 } 181 182 setup_sigcontext(&frame->sc, regs, set->sig[0]); 183 184 for (i = 0; i < TARGET_NSIG_WORDS - 1; i++) { 185 __put_user(set->sig[i + 1], &frame->extramask[i]); 186 } 187 188 /* Set up to return from userspace. If provided, use a stub 189 already in userspace. */ 190 if (ka->sa_flags & TARGET_SA_RESTORER) { 191 regs->pr = ka->sa_restorer; 192 } else { 193 regs->pr = default_sigreturn; 194 } 195 196 /* Set up registers for signal handler */ 197 regs->gregs[15] = frame_addr; 198 regs->gregs[4] = sig; /* Arg for signal handler */ 199 regs->gregs[5] = 0; 200 regs->gregs[6] = frame_addr += offsetof(typeof(*frame), sc); 201 regs->pc = (unsigned long) ka->_sa_handler; 202 regs->flags &= ~(TB_FLAG_DELAY_SLOT_MASK | TB_FLAG_GUSA_MASK); 203 204 unlock_user_struct(frame, frame_addr, 1); 205 return; 206 207 give_sigsegv: 208 unlock_user_struct(frame, frame_addr, 1); 209 force_sigsegv(sig); 210 } 211 212 void setup_rt_frame(int sig, struct target_sigaction *ka, 213 target_siginfo_t *info, 214 target_sigset_t *set, CPUSH4State *regs) 215 { 216 struct target_rt_sigframe *frame; 217 abi_ulong frame_addr; 218 int i; 219 220 unwind_gusa(regs); 221 222 frame_addr = get_sigframe(ka, regs->gregs[15], sizeof(*frame)); 223 trace_user_setup_rt_frame(regs, frame_addr); 224 if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) { 225 goto give_sigsegv; 226 } 227 228 tswap_siginfo(&frame->info, info); 229 230 /* Create the ucontext. */ 231 __put_user(0, &frame->uc.tuc_flags); 232 __put_user(0, (unsigned long *)&frame->uc.tuc_link); 233 target_save_altstack(&frame->uc.tuc_stack, regs); 234 setup_sigcontext(&frame->uc.tuc_mcontext, 235 regs, set->sig[0]); 236 for(i = 0; i < TARGET_NSIG_WORDS; i++) { 237 __put_user(set->sig[i], &frame->uc.tuc_sigmask.sig[i]); 238 } 239 240 /* Set up to return from userspace. If provided, use a stub 241 already in userspace. */ 242 if (ka->sa_flags & TARGET_SA_RESTORER) { 243 regs->pr = ka->sa_restorer; 244 } else { 245 regs->pr = default_rt_sigreturn; 246 } 247 248 /* Set up registers for signal handler */ 249 regs->gregs[15] = frame_addr; 250 regs->gregs[4] = sig; /* Arg for signal handler */ 251 regs->gregs[5] = frame_addr + offsetof(typeof(*frame), info); 252 regs->gregs[6] = frame_addr + offsetof(typeof(*frame), uc); 253 regs->pc = (unsigned long) ka->_sa_handler; 254 regs->flags &= ~(TB_FLAG_DELAY_SLOT_MASK | TB_FLAG_GUSA_MASK); 255 256 unlock_user_struct(frame, frame_addr, 1); 257 return; 258 259 give_sigsegv: 260 unlock_user_struct(frame, frame_addr, 1); 261 force_sigsegv(sig); 262 } 263 264 long do_sigreturn(CPUSH4State *regs) 265 { 266 struct target_sigframe *frame; 267 abi_ulong frame_addr; 268 sigset_t blocked; 269 target_sigset_t target_set; 270 int i; 271 272 frame_addr = regs->gregs[15]; 273 trace_user_do_sigreturn(regs, frame_addr); 274 if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) { 275 goto badframe; 276 } 277 278 __get_user(target_set.sig[0], &frame->sc.oldmask); 279 for(i = 1; i < TARGET_NSIG_WORDS; i++) { 280 __get_user(target_set.sig[i], &frame->extramask[i - 1]); 281 } 282 283 target_to_host_sigset_internal(&blocked, &target_set); 284 set_sigmask(&blocked); 285 286 restore_sigcontext(regs, &frame->sc); 287 288 unlock_user_struct(frame, frame_addr, 0); 289 return -QEMU_ESIGRETURN; 290 291 badframe: 292 unlock_user_struct(frame, frame_addr, 0); 293 force_sig(TARGET_SIGSEGV); 294 return -QEMU_ESIGRETURN; 295 } 296 297 long do_rt_sigreturn(CPUSH4State *regs) 298 { 299 struct target_rt_sigframe *frame; 300 abi_ulong frame_addr; 301 sigset_t blocked; 302 303 frame_addr = regs->gregs[15]; 304 trace_user_do_rt_sigreturn(regs, frame_addr); 305 if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) { 306 goto badframe; 307 } 308 309 target_to_host_sigset(&blocked, &frame->uc.tuc_sigmask); 310 set_sigmask(&blocked); 311 312 restore_sigcontext(regs, &frame->uc.tuc_mcontext); 313 target_restore_altstack(&frame->uc.tuc_stack, regs); 314 315 unlock_user_struct(frame, frame_addr, 0); 316 return -QEMU_ESIGRETURN; 317 318 badframe: 319 unlock_user_struct(frame, frame_addr, 0); 320 force_sig(TARGET_SIGSEGV); 321 return -QEMU_ESIGRETURN; 322 } 323 324 void setup_sigtramp(abi_ulong sigtramp_page) 325 { 326 uint16_t *tramp = lock_user(VERIFY_WRITE, sigtramp_page, 2 * 6, 0); 327 assert(tramp != NULL); 328 329 default_sigreturn = sigtramp_page; 330 __put_user(MOVW(2), &tramp[0]); 331 __put_user(TRAP_NOARG, &tramp[1]); 332 __put_user(TARGET_NR_sigreturn, &tramp[2]); 333 334 default_rt_sigreturn = sigtramp_page + 6; 335 __put_user(MOVW(2), &tramp[3]); 336 __put_user(TRAP_NOARG, &tramp[4]); 337 __put_user(TARGET_NR_rt_sigreturn, &tramp[5]); 338 339 unlock_user(tramp, sigtramp_page, 2 * 6); 340 } 341