| 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 | __put_user(regs->active_fpu.fcr31, &sc->sc_fpc_csr); |
| 138 | } |
| 139 | |
| 140 | static inline void |
| 141 | restore_sigcontext(CPUMIPSState *regs, struct target_sigcontext *sc) |
| 142 | { |
| 143 | int i; |
| 144 | |
| 145 | __get_user(regs->CP0_EPC, &sc->sc_pc); |
| 146 | |
| 147 | __get_user(regs->active_tc.HI[0], &sc->sc_mdhi); |
| 148 | __get_user(regs->active_tc.LO[0], &sc->sc_mdlo); |
| 149 | |
| 150 | for (i = 1; i < 32; ++i) { |
| 151 | __get_user(regs->active_tc.gpr[i], &sc->sc_regs[i]); |
| 152 | } |
| 153 | |
| 154 | __get_user(regs->active_tc.HI[1], &sc->sc_hi1); |
| 155 | __get_user(regs->active_tc.HI[2], &sc->sc_hi2); |
| 156 | __get_user(regs->active_tc.HI[3], &sc->sc_hi3); |
| 157 | __get_user(regs->active_tc.LO[1], &sc->sc_lo1); |
| 158 | __get_user(regs->active_tc.LO[2], &sc->sc_lo2); |
| 159 | __get_user(regs->active_tc.LO[3], &sc->sc_lo3); |
| 160 | { |
| 161 | uint32_t dsp; |
| 162 | __get_user(dsp, &sc->sc_dsp); |
| 163 | cpu_wrdsp(dsp, 0x3ff, regs); |
| 164 | } |
| 165 | |
| 166 | for (i = 0; i < 32; ++i) { |
| 167 | __get_user(regs->active_fpu.fpr[i].d, &sc->sc_fpregs[i]); |
| 168 | } |
| 169 | { |
| 170 | uint32_t fcr31; |
| 171 | __get_user(fcr31, &sc->sc_fpc_csr); |
| 172 | regs->active_fpu.fcr31 = fcr31 & regs->active_fpu.fcr31_rw_bitmask; |
| 173 | cpu_mips_restore_fp_status(regs); |
| 174 | } |
| 175 | } |
| 176 | |
| 177 | /* |
| 178 | * Determine which stack to use.. |
| 179 | */ |
| 180 | static inline abi_ulong |
| 181 | get_sigframe(struct target_sigaction *ka, CPUMIPSState *regs, size_t frame_size) |
| 182 | { |
| 183 | unsigned long sp; |
| 184 | |
| 185 | /* |
| 186 | * FPU emulator may have its own trampoline active just |
| 187 | * above the user stack, 16-bytes before the next lowest |
| 188 | * 16 byte boundary. Try to avoid trashing it. |
| 189 | */ |
| 190 | sp = target_sigsp(get_sp_from_cpustate(regs) - 32, ka); |
| 191 | |
| 192 | return (sp - frame_size) & ~7; |
| 193 | } |
| 194 | |
| 195 | static void mips_set_hflags_isa_mode_from_pc(CPUMIPSState *env) |
| 196 | { |
| 197 | if (env->insn_flags & (ASE_MIPS16 | ASE_MICROMIPS)) { |
| 198 | env->hflags &= ~MIPS_HFLAG_M16; |
| 199 | env->hflags |= (env->active_tc.PC & 1) << MIPS_HFLAG_M16_SHIFT; |
| 200 | env->active_tc.PC &= ~(target_ulong) 1; |
| 201 | } |
| 202 | } |
| 203 | |
| 204 | # if defined(TARGET_ABI_MIPSO32) |
| 205 | /* compare linux/arch/mips/kernel/signal.c:setup_frame() */ |
| 206 | void setup_frame(int sig, struct target_sigaction * ka, |
| 207 | target_sigset_t *set, CPUMIPSState *regs) |
| 208 | { |
| 209 | struct sigframe *frame; |
| 210 | abi_ulong frame_addr; |
| 211 | int i; |
| 212 | |
| 213 | frame_addr = get_sigframe(ka, regs, sizeof(*frame)); |
| 214 | trace_user_setup_frame(regs, frame_addr); |
| 215 | if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) { |
| 216 | goto give_sigsegv; |
| 217 | } |
| 218 | |
| 219 | setup_sigcontext(regs, &frame->sf_sc); |
| 220 | |
| 221 | for(i = 0; i < TARGET_NSIG_WORDS; i++) { |
| 222 | __put_user(set->sig[i], &frame->sf_mask.sig[i]); |
| 223 | } |
| 224 | |
| 225 | /* |
| 226 | * Arguments to signal handler: |
| 227 | * |
| 228 | * a0 = signal number |
| 229 | * a1 = 0 (should be cause) |
| 230 | * a2 = pointer to struct sigcontext |
| 231 | * |
| 232 | * $25 and PC point to the signal handler, $29 points to the |
| 233 | * struct sigframe. |
| 234 | */ |
| 235 | regs->active_tc.gpr[ 4] = sig; |
| 236 | regs->active_tc.gpr[ 5] = 0; |
| 237 | regs->active_tc.gpr[ 6] = frame_addr + offsetof(struct sigframe, sf_sc); |
| 238 | regs->active_tc.gpr[29] = frame_addr; |
| 239 | regs->active_tc.gpr[31] = default_sigreturn; |
| 240 | /* The original kernel code sets CP0_EPC to the handler |
| 241 | * since it returns to userland using eret |
| 242 | * we cannot do this here, and we must set PC directly */ |
| 243 | regs->active_tc.PC = regs->active_tc.gpr[25] = ka->_sa_handler; |
| 244 | mips_set_hflags_isa_mode_from_pc(regs); |
| 245 | unlock_user_struct(frame, frame_addr, 1); |
| 246 | return; |
| 247 | |
| 248 | give_sigsegv: |
| 249 | force_sigsegv(sig); |
| 250 | } |
| 251 | |
| 252 | long do_sigreturn(CPUMIPSState *regs) |
| 253 | { |
| 254 | struct sigframe *frame; |
| 255 | abi_ulong frame_addr; |
| 256 | sigset_t blocked; |
| 257 | target_sigset_t target_set; |
| 258 | int i; |
| 259 | |
| 260 | frame_addr = regs->active_tc.gpr[29]; |
| 261 | trace_user_do_sigreturn(regs, frame_addr); |
| 262 | if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) |
| 263 | goto badframe; |
| 264 | |
| 265 | for(i = 0; i < TARGET_NSIG_WORDS; i++) { |
| 266 | __get_user(target_set.sig[i], &frame->sf_mask.sig[i]); |
| 267 | } |
| 268 | |
| 269 | target_to_host_sigset_internal(&blocked, &target_set); |
| 270 | set_sigmask(&blocked); |
| 271 | |
| 272 | restore_sigcontext(regs, &frame->sf_sc); |
| 273 | |
| 274 | #if 0 |
| 275 | /* |
| 276 | * Don't let your children do this ... |
| 277 | */ |
| 278 | __asm__ __volatile__( |
| 279 | "move\t$29, %0\n\t" |
| 280 | "j\tsyscall_exit" |
| 281 | :/* no outputs */ |
| 282 | :"r" (®s)); |
| 283 | /* Unreached */ |
| 284 | #endif |
| 285 | |
| 286 | regs->active_tc.PC = regs->CP0_EPC; |
| 287 | mips_set_hflags_isa_mode_from_pc(regs); |
| 288 | /* I am not sure this is right, but it seems to work |
| 289 | * maybe a problem with nested signals ? */ |
| 290 | regs->CP0_EPC = 0; |
| 291 | return -QEMU_ESIGRETURN; |
| 292 | |
| 293 | badframe: |
| 294 | force_sig(TARGET_SIGSEGV); |
| 295 | return -QEMU_ESIGRETURN; |
| 296 | } |
| 297 | # endif /* O32 */ |
| 298 | |
| 299 | void setup_rt_frame(int sig, struct target_sigaction *ka, |
| 300 | target_siginfo_t *info, |
| 301 | target_sigset_t *set, CPUMIPSState *env) |
| 302 | { |
| 303 | struct target_rt_sigframe *frame; |
| 304 | abi_ulong frame_addr; |
| 305 | int i; |
| 306 | |
| 307 | frame_addr = get_sigframe(ka, env, sizeof(*frame)); |
| 308 | trace_user_setup_rt_frame(env, frame_addr); |
| 309 | if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) { |
| 310 | goto give_sigsegv; |
| 311 | } |
| 312 | |
| 313 | frame->rs_info = *info; |
| 314 | |
| 315 | __put_user(0, &frame->rs_uc.tuc_flags); |
| 316 | __put_user(0, &frame->rs_uc.tuc_link); |
| 317 | target_save_altstack(&frame->rs_uc.tuc_stack, env); |
| 318 | |
| 319 | setup_sigcontext(env, &frame->rs_uc.tuc_mcontext); |
| 320 | |
| 321 | for (i = 0; i < TARGET_NSIG_WORDS; i++) { |
| 322 | __put_user(set->sig[i], &frame->rs_uc.tuc_sigmask.sig[i]); |
| 323 | } |
| 324 | |
| 325 | /* |
| 326 | * Arguments to signal handler: |
| 327 | * |
| 328 | * a0 = signal number |
| 329 | * a1 = pointer to siginfo_t |
| 330 | * a2 = pointer to ucontext_t |
| 331 | * |
| 332 | * $25 and PC point to the signal handler, $29 points to the |
| 333 | * struct sigframe. |
| 334 | */ |
| 335 | env->active_tc.gpr[ 4] = sig; |
| 336 | env->active_tc.gpr[ 5] = frame_addr |
| 337 | + offsetof(struct target_rt_sigframe, rs_info); |
| 338 | env->active_tc.gpr[ 6] = frame_addr |
| 339 | + offsetof(struct target_rt_sigframe, rs_uc); |
| 340 | env->active_tc.gpr[29] = frame_addr; |
| 341 | env->active_tc.gpr[31] = default_rt_sigreturn; |
| 342 | |
| 343 | /* |
| 344 | * The original kernel code sets CP0_EPC to the handler |
| 345 | * since it returns to userland using eret |
| 346 | * we cannot do this here, and we must set PC directly |
| 347 | */ |
| 348 | env->active_tc.PC = env->active_tc.gpr[25] = ka->_sa_handler; |
| 349 | mips_set_hflags_isa_mode_from_pc(env); |
| 350 | unlock_user_struct(frame, frame_addr, 1); |
| 351 | return; |
| 352 | |
| 353 | give_sigsegv: |
| 354 | unlock_user_struct(frame, frame_addr, 1); |
| 355 | force_sigsegv(sig); |
| 356 | } |
| 357 | |
| 358 | long do_rt_sigreturn(CPUMIPSState *env) |
| 359 | { |
| 360 | struct target_rt_sigframe *frame; |
| 361 | abi_ulong frame_addr; |
| 362 | sigset_t blocked; |
| 363 | |
| 364 | frame_addr = env->active_tc.gpr[29]; |
| 365 | trace_user_do_rt_sigreturn(env, frame_addr); |
| 366 | if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) { |
| 367 | goto badframe; |
| 368 | } |
| 369 | |
| 370 | target_to_host_sigset(&blocked, &frame->rs_uc.tuc_sigmask); |
| 371 | set_sigmask(&blocked); |
| 372 | |
| 373 | restore_sigcontext(env, &frame->rs_uc.tuc_mcontext); |
| 374 | target_restore_altstack(&frame->rs_uc.tuc_stack, env); |
| 375 | |
| 376 | env->active_tc.PC = env->CP0_EPC; |
| 377 | mips_set_hflags_isa_mode_from_pc(env); |
| 378 | /* I am not sure this is right, but it seems to work |
| 379 | * maybe a problem with nested signals ? */ |
| 380 | env->CP0_EPC = 0; |
| 381 | return -QEMU_ESIGRETURN; |
| 382 | |
| 383 | badframe: |
| 384 | force_sig(TARGET_SIGSEGV); |
| 385 | return -QEMU_ESIGRETURN; |
| 386 | } |
| 387 | |
| 388 | void setup_sigtramp(abi_ulong sigtramp_page) |
| 389 | { |
| 390 | uint32_t *tramp = lock_user(VERIFY_WRITE, sigtramp_page, 2 * 8, 0); |
| 391 | assert(tramp != NULL); |
| 392 | |
| 393 | #ifdef TARGET_ARCH_HAS_SETUP_FRAME |
| 394 | default_sigreturn = sigtramp_page; |
| 395 | install_sigtramp(tramp, TARGET_NR_sigreturn); |
| 396 | #endif |
| 397 | |
| 398 | default_rt_sigreturn = sigtramp_page + 8; |
| 399 | install_sigtramp(tramp + 2, TARGET_NR_rt_sigreturn); |
| 400 | |
| 401 | unlock_user(tramp, sigtramp_page, 2 * 8); |
| 402 | } |