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 # if defined(TARGET_ABI_MIPSO32) 26 struct target_sigcontext { 27 uint32_t sc_regmask; /* Unused */ 28 uint32_t sc_status; 29 uint64_t sc_pc; 30 uint64_t sc_regs[32]; 31 uint64_t sc_fpregs[32]; 32 uint32_t sc_ownedfp; /* Unused */ 33 uint32_t sc_fpc_csr; 34 uint32_t sc_fpc_eir; /* Unused */ 35 uint32_t sc_used_math; 36 uint32_t sc_dsp; /* dsp status, was sc_ssflags */ 37 uint32_t pad0; 38 uint64_t sc_mdhi; 39 uint64_t sc_mdlo; 40 target_ulong sc_hi1; /* Was sc_cause */ 41 target_ulong sc_lo1; /* Was sc_badvaddr */ 42 target_ulong sc_hi2; /* Was sc_sigset[4] */ 43 target_ulong sc_lo2; 44 target_ulong sc_hi3; 45 target_ulong sc_lo3; 46 }; 47 # else /* N32 || N64 */ 48 struct target_sigcontext { 49 uint64_t sc_regs[32]; 50 uint64_t sc_fpregs[32]; 51 uint64_t sc_mdhi; 52 uint64_t sc_hi1; 53 uint64_t sc_hi2; 54 uint64_t sc_hi3; 55 uint64_t sc_mdlo; 56 uint64_t sc_lo1; 57 uint64_t sc_lo2; 58 uint64_t sc_lo3; 59 uint64_t sc_pc; 60 uint32_t sc_fpc_csr; 61 uint32_t sc_used_math; 62 uint32_t sc_dsp; 63 uint32_t sc_reserved; 64 }; 65 # endif /* O32 */ 66 67 struct sigframe { 68 uint32_t sf_ass[4]; /* argument save space for o32 */ 69 uint32_t sf_code[2]; /* signal trampoline */ 70 struct target_sigcontext sf_sc; 71 target_sigset_t sf_mask; 72 }; 73 74 struct target_ucontext { 75 abi_ulong tuc_flags; 76 abi_ulong tuc_link; 77 target_stack_t tuc_stack; 78 struct target_sigcontext tuc_mcontext; 79 target_sigset_t tuc_sigmask; 80 }; 81 82 struct target_rt_sigframe { 83 uint32_t rs_ass[4]; /* argument save space for o32 */ 84 uint32_t rs_code[2]; /* signal trampoline */ 85 struct target_siginfo rs_info; 86 struct target_ucontext rs_uc; 87 }; 88 89 /* Install trampoline to jump back from signal handler */ 90 static void install_sigtramp(uint32_t *tramp, unsigned int syscall) 91 { 92 /* 93 * Set up the return code ... 94 * 95 * li v0, __NR__foo_sigreturn 96 * syscall 97 */ 98 99 __put_user(0x24020000 + syscall, tramp + 0); 100 __put_user(0x0000000c , tramp + 1); 101 } 102 103 static inline void setup_sigcontext(CPUMIPSState *regs, 104 struct target_sigcontext *sc) 105 { 106 int i; 107 108 __put_user(exception_resume_pc(regs), &sc->sc_pc); 109 regs->hflags &= ~MIPS_HFLAG_BMASK; 110 111 __put_user(0, &sc->sc_regs[0]); 112 for (i = 1; i < 32; ++i) { 113 __put_user(regs->active_tc.gpr[i], &sc->sc_regs[i]); 114 } 115 116 __put_user(regs->active_tc.HI[0], &sc->sc_mdhi); 117 __put_user(regs->active_tc.LO[0], &sc->sc_mdlo); 118 119 /* Rather than checking for dsp existence, always copy. The storage 120 would just be garbage otherwise. */ 121 __put_user(regs->active_tc.HI[1], &sc->sc_hi1); 122 __put_user(regs->active_tc.HI[2], &sc->sc_hi2); 123 __put_user(regs->active_tc.HI[3], &sc->sc_hi3); 124 __put_user(regs->active_tc.LO[1], &sc->sc_lo1); 125 __put_user(regs->active_tc.LO[2], &sc->sc_lo2); 126 __put_user(regs->active_tc.LO[3], &sc->sc_lo3); 127 { 128 uint32_t dsp = cpu_rddsp(0x3ff, regs); 129 __put_user(dsp, &sc->sc_dsp); 130 } 131 132 __put_user(1, &sc->sc_used_math); 133 134 for (i = 0; i < 32; ++i) { 135 __put_user(regs->active_fpu.fpr[i].d, &sc->sc_fpregs[i]); 136 } 137 } 138 139 static inline void 140 restore_sigcontext(CPUMIPSState *regs, struct target_sigcontext *sc) 141 { 142 int i; 143 144 __get_user(regs->CP0_EPC, &sc->sc_pc); 145 146 __get_user(regs->active_tc.HI[0], &sc->sc_mdhi); 147 __get_user(regs->active_tc.LO[0], &sc->sc_mdlo); 148 149 for (i = 1; i < 32; ++i) { 150 __get_user(regs->active_tc.gpr[i], &sc->sc_regs[i]); 151 } 152 153 __get_user(regs->active_tc.HI[1], &sc->sc_hi1); 154 __get_user(regs->active_tc.HI[2], &sc->sc_hi2); 155 __get_user(regs->active_tc.HI[3], &sc->sc_hi3); 156 __get_user(regs->active_tc.LO[1], &sc->sc_lo1); 157 __get_user(regs->active_tc.LO[2], &sc->sc_lo2); 158 __get_user(regs->active_tc.LO[3], &sc->sc_lo3); 159 { 160 uint32_t dsp; 161 __get_user(dsp, &sc->sc_dsp); 162 cpu_wrdsp(dsp, 0x3ff, regs); 163 } 164 165 for (i = 0; i < 32; ++i) { 166 __get_user(regs->active_fpu.fpr[i].d, &sc->sc_fpregs[i]); 167 } 168 } 169 170 /* 171 * Determine which stack to use.. 172 */ 173 static inline abi_ulong 174 get_sigframe(struct target_sigaction *ka, CPUMIPSState *regs, size_t frame_size) 175 { 176 unsigned long sp; 177 178 /* 179 * FPU emulator may have its own trampoline active just 180 * above the user stack, 16-bytes before the next lowest 181 * 16 byte boundary. Try to avoid trashing it. 182 */ 183 sp = target_sigsp(get_sp_from_cpustate(regs) - 32, ka); 184 185 return (sp - frame_size) & ~7; 186 } 187 188 static void mips_set_hflags_isa_mode_from_pc(CPUMIPSState *env) 189 { 190 if (env->insn_flags & (ASE_MIPS16 | ASE_MICROMIPS)) { 191 env->hflags &= ~MIPS_HFLAG_M16; 192 env->hflags |= (env->active_tc.PC & 1) << MIPS_HFLAG_M16_SHIFT; 193 env->active_tc.PC &= ~(target_ulong) 1; 194 } 195 } 196 197 # if defined(TARGET_ABI_MIPSO32) 198 /* compare linux/arch/mips/kernel/signal.c:setup_frame() */ 199 void setup_frame(int sig, struct target_sigaction * ka, 200 target_sigset_t *set, CPUMIPSState *regs) 201 { 202 struct sigframe *frame; 203 abi_ulong frame_addr; 204 int i; 205 206 frame_addr = get_sigframe(ka, regs, sizeof(*frame)); 207 trace_user_setup_frame(regs, frame_addr); 208 if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) { 209 goto give_sigsegv; 210 } 211 212 install_sigtramp(frame->sf_code, TARGET_NR_sigreturn); 213 214 setup_sigcontext(regs, &frame->sf_sc); 215 216 for(i = 0; i < TARGET_NSIG_WORDS; i++) { 217 __put_user(set->sig[i], &frame->sf_mask.sig[i]); 218 } 219 220 /* 221 * Arguments to signal handler: 222 * 223 * a0 = signal number 224 * a1 = 0 (should be cause) 225 * a2 = pointer to struct sigcontext 226 * 227 * $25 and PC point to the signal handler, $29 points to the 228 * struct sigframe. 229 */ 230 regs->active_tc.gpr[ 4] = sig; 231 regs->active_tc.gpr[ 5] = 0; 232 regs->active_tc.gpr[ 6] = frame_addr + offsetof(struct sigframe, sf_sc); 233 regs->active_tc.gpr[29] = frame_addr; 234 regs->active_tc.gpr[31] = frame_addr + offsetof(struct sigframe, sf_code); 235 /* The original kernel code sets CP0_EPC to the handler 236 * since it returns to userland using eret 237 * we cannot do this here, and we must set PC directly */ 238 regs->active_tc.PC = regs->active_tc.gpr[25] = ka->_sa_handler; 239 mips_set_hflags_isa_mode_from_pc(regs); 240 unlock_user_struct(frame, frame_addr, 1); 241 return; 242 243 give_sigsegv: 244 force_sigsegv(sig); 245 } 246 247 long do_sigreturn(CPUMIPSState *regs) 248 { 249 struct sigframe *frame; 250 abi_ulong frame_addr; 251 sigset_t blocked; 252 target_sigset_t target_set; 253 int i; 254 255 frame_addr = regs->active_tc.gpr[29]; 256 trace_user_do_sigreturn(regs, frame_addr); 257 if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) 258 goto badframe; 259 260 for(i = 0; i < TARGET_NSIG_WORDS; i++) { 261 __get_user(target_set.sig[i], &frame->sf_mask.sig[i]); 262 } 263 264 target_to_host_sigset_internal(&blocked, &target_set); 265 set_sigmask(&blocked); 266 267 restore_sigcontext(regs, &frame->sf_sc); 268 269 #if 0 270 /* 271 * Don't let your children do this ... 272 */ 273 __asm__ __volatile__( 274 "move\t$29, %0\n\t" 275 "j\tsyscall_exit" 276 :/* no outputs */ 277 :"r" (®s)); 278 /* Unreached */ 279 #endif 280 281 regs->active_tc.PC = regs->CP0_EPC; 282 mips_set_hflags_isa_mode_from_pc(regs); 283 /* I am not sure this is right, but it seems to work 284 * maybe a problem with nested signals ? */ 285 regs->CP0_EPC = 0; 286 return -TARGET_QEMU_ESIGRETURN; 287 288 badframe: 289 force_sig(TARGET_SIGSEGV); 290 return -TARGET_QEMU_ESIGRETURN; 291 } 292 # endif /* O32 */ 293 294 void setup_rt_frame(int sig, struct target_sigaction *ka, 295 target_siginfo_t *info, 296 target_sigset_t *set, CPUMIPSState *env) 297 { 298 struct target_rt_sigframe *frame; 299 abi_ulong frame_addr; 300 int i; 301 302 frame_addr = get_sigframe(ka, env, sizeof(*frame)); 303 trace_user_setup_rt_frame(env, frame_addr); 304 if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) { 305 goto give_sigsegv; 306 } 307 308 install_sigtramp(frame->rs_code, TARGET_NR_rt_sigreturn); 309 310 tswap_siginfo(&frame->rs_info, info); 311 312 __put_user(0, &frame->rs_uc.tuc_flags); 313 __put_user(0, &frame->rs_uc.tuc_link); 314 target_save_altstack(&frame->rs_uc.tuc_stack, env); 315 316 setup_sigcontext(env, &frame->rs_uc.tuc_mcontext); 317 318 for(i = 0; i < TARGET_NSIG_WORDS; i++) { 319 __put_user(set->sig[i], &frame->rs_uc.tuc_sigmask.sig[i]); 320 } 321 322 /* 323 * Arguments to signal handler: 324 * 325 * a0 = signal number 326 * a1 = pointer to siginfo_t 327 * a2 = pointer to ucontext_t 328 * 329 * $25 and PC point to the signal handler, $29 points to the 330 * struct sigframe. 331 */ 332 env->active_tc.gpr[ 4] = sig; 333 env->active_tc.gpr[ 5] = frame_addr 334 + offsetof(struct target_rt_sigframe, rs_info); 335 env->active_tc.gpr[ 6] = frame_addr 336 + offsetof(struct target_rt_sigframe, rs_uc); 337 env->active_tc.gpr[29] = frame_addr; 338 env->active_tc.gpr[31] = frame_addr 339 + offsetof(struct target_rt_sigframe, rs_code); 340 /* The original kernel code sets CP0_EPC to the handler 341 * since it returns to userland using eret 342 * we cannot do this here, and we must set PC directly */ 343 env->active_tc.PC = env->active_tc.gpr[25] = ka->_sa_handler; 344 mips_set_hflags_isa_mode_from_pc(env); 345 unlock_user_struct(frame, frame_addr, 1); 346 return; 347 348 give_sigsegv: 349 unlock_user_struct(frame, frame_addr, 1); 350 force_sigsegv(sig); 351 } 352 353 long do_rt_sigreturn(CPUMIPSState *env) 354 { 355 struct target_rt_sigframe *frame; 356 abi_ulong frame_addr; 357 sigset_t blocked; 358 359 frame_addr = env->active_tc.gpr[29]; 360 trace_user_do_rt_sigreturn(env, frame_addr); 361 if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) { 362 goto badframe; 363 } 364 365 target_to_host_sigset(&blocked, &frame->rs_uc.tuc_sigmask); 366 set_sigmask(&blocked); 367 368 restore_sigcontext(env, &frame->rs_uc.tuc_mcontext); 369 target_restore_altstack(&frame->rs_uc.tuc_stack, env); 370 371 env->active_tc.PC = env->CP0_EPC; 372 mips_set_hflags_isa_mode_from_pc(env); 373 /* I am not sure this is right, but it seems to work 374 * maybe a problem with nested signals ? */ 375 env->CP0_EPC = 0; 376 return -TARGET_QEMU_ESIGRETURN; 377 378 badframe: 379 force_sig(TARGET_SIGSEGV); 380 return -TARGET_QEMU_ESIGRETURN; 381 } 382