| 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 | #include "target/xtensa/cpu.h" |
| 25 | |
| 26 | struct target_sigcontext { |
| 27 | abi_ulong sc_pc; |
| 28 | abi_ulong sc_ps; |
| 29 | abi_ulong sc_lbeg; |
| 30 | abi_ulong sc_lend; |
| 31 | abi_ulong sc_lcount; |
| 32 | abi_ulong sc_sar; |
| 33 | abi_ulong sc_acclo; |
| 34 | abi_ulong sc_acchi; |
| 35 | abi_ulong sc_a[16]; |
| 36 | abi_ulong sc_xtregs; |
| 37 | }; |
| 38 | |
| 39 | struct target_ucontext { |
| 40 | abi_ulong tuc_flags; |
| 41 | abi_ulong tuc_link; |
| 42 | target_stack_t tuc_stack; |
| 43 | struct target_sigcontext tuc_mcontext; |
| 44 | target_sigset_t tuc_sigmask; |
| 45 | }; |
| 46 | |
| 47 | struct target_xtensa_xtregs_fp { |
| 48 | uint32_t f[16]; |
| 49 | uint32_t fcr; |
| 50 | uint32_t fsr; |
| 51 | }; |
| 52 | |
| 53 | struct target_xtensa_xtregs_dfp { |
| 54 | uint64_t f[16]; |
| 55 | uint32_t fcr; |
| 56 | uint32_t fsr; |
| 57 | }; |
| 58 | |
| 59 | struct target_rt_sigframe { |
| 60 | target_siginfo_t info; |
| 61 | struct target_ucontext uc; |
| 62 | union { |
| 63 | struct target_xtensa_xtregs_fp fp; |
| 64 | struct target_xtensa_xtregs_dfp dfp; |
| 65 | } xtregs; |
| 66 | uint8_t retcode[6]; |
| 67 | abi_ulong window[4]; |
| 68 | }; |
| 69 | |
| 70 | static abi_ulong get_sigframe(struct target_sigaction *sa, |
| 71 | CPUXtensaState *env, |
| 72 | unsigned long framesize) |
| 73 | { |
| 74 | abi_ulong sp; |
| 75 | |
| 76 | sp = target_sigsp(get_sp_from_cpustate(env), sa); |
| 77 | |
| 78 | return (sp - framesize) & -16; |
| 79 | } |
| 80 | |
| 81 | static int flush_window_regs(CPUXtensaState *env) |
| 82 | { |
| 83 | uint32_t wb = env->sregs[WINDOW_BASE]; |
| 84 | uint32_t ws = xtensa_replicate_windowstart(env) >> (wb + 1); |
| 85 | unsigned d = ctz32(ws) + 1; |
| 86 | unsigned i; |
| 87 | int ret = 0; |
| 88 | |
| 89 | for (i = d; i < env->config->nareg / 4; i += d) { |
| 90 | uint32_t ssp, osp; |
| 91 | unsigned j; |
| 92 | |
| 93 | ws >>= d; |
| 94 | xtensa_rotate_window(env, d); |
| 95 | |
| 96 | if (ws & 0x1) { |
| 97 | ssp = env->regs[5]; |
| 98 | d = 1; |
| 99 | } else if (ws & 0x2) { |
| 100 | ssp = env->regs[9]; |
| 101 | ret |= get_user_ual(osp, env->regs[1] - 12); |
| 102 | osp -= 32; |
| 103 | d = 2; |
| 104 | } else if (ws & 0x4) { |
| 105 | ssp = env->regs[13]; |
| 106 | ret |= get_user_ual(osp, env->regs[1] - 12); |
| 107 | osp -= 48; |
| 108 | d = 3; |
| 109 | } else { |
| 110 | g_assert_not_reached(); |
| 111 | } |
| 112 | |
| 113 | for (j = 0; j < 4; ++j) { |
| 114 | ret |= put_user_ual(env->regs[j], ssp - 16 + j * 4); |
| 115 | } |
| 116 | for (j = 4; j < d * 4; ++j) { |
| 117 | ret |= put_user_ual(env->regs[j], osp - 16 + j * 4); |
| 118 | } |
| 119 | } |
| 120 | xtensa_rotate_window(env, d); |
| 121 | g_assert(env->sregs[WINDOW_BASE] == wb); |
| 122 | return ret == 0; |
| 123 | } |
| 124 | |
| 125 | static int setup_sigcontext(struct target_rt_sigframe *frame, |
| 126 | abi_ulong frame_addr, |
| 127 | CPUXtensaState *env) |
| 128 | { |
| 129 | struct target_sigcontext *sc = &frame->uc.tuc_mcontext; |
| 130 | int i; |
| 131 | |
| 132 | __put_user(env->pc, &sc->sc_pc); |
| 133 | __put_user(env->sregs[PS], &sc->sc_ps); |
| 134 | __put_user(env->sregs[LBEG], &sc->sc_lbeg); |
| 135 | __put_user(env->sregs[LEND], &sc->sc_lend); |
| 136 | __put_user(env->sregs[LCOUNT], &sc->sc_lcount); |
| 137 | if (!flush_window_regs(env)) { |
| 138 | return 0; |
| 139 | } |
| 140 | for (i = 0; i < 16; ++i) { |
| 141 | __put_user(env->regs[i], sc->sc_a + i); |
| 142 | } |
| 143 | if (xtensa_option_enabled(env->config, XTENSA_OPTION_DFP_COPROCESSOR)) { |
| 144 | for (i = 0; i < 16; ++i) { |
| 145 | __put_user(env->fregs[i].f64, &frame->xtregs.dfp.f[i]); |
| 146 | } |
| 147 | __put_user(env->uregs[FCR], &frame->xtregs.dfp.fcr); |
| 148 | __put_user(cpu_get_fsr(env), &frame->xtregs.dfp.fsr); |
| 149 | __put_user(frame_addr + offsetof(struct target_rt_sigframe, xtregs), |
| 150 | &sc->sc_xtregs); |
| 151 | } else if (xtensa_option_enabled(env->config, XTENSA_OPTION_FP_COPROCESSOR)) { |
| 152 | for (i = 0; i < 16; ++i) { |
| 153 | __put_user(env->fregs[i].f32[FP_F32_LOW], &frame->xtregs.fp.f[i]); |
| 154 | } |
| 155 | __put_user(env->uregs[FCR], &frame->xtregs.fp.fcr); |
| 156 | __put_user(cpu_get_fsr(env), &frame->xtregs.fp.fsr); |
| 157 | __put_user(frame_addr + offsetof(struct target_rt_sigframe, xtregs), |
| 158 | &sc->sc_xtregs); |
| 159 | } else { |
| 160 | __put_user(0, &sc->sc_xtregs); |
| 161 | } |
| 162 | return 1; |
| 163 | } |
| 164 | |
| 165 | static void install_sigtramp(uint8_t *tramp) |
| 166 | { |
| 167 | #if TARGET_BIG_ENDIAN |
| 168 | /* Generate instruction: MOVI a2, __NR_rt_sigreturn */ |
| 169 | __put_user(0x22, &tramp[0]); |
| 170 | __put_user(0x0a, &tramp[1]); |
| 171 | __put_user(TARGET_NR_rt_sigreturn, &tramp[2]); |
| 172 | /* Generate instruction: SYSCALL */ |
| 173 | __put_user(0x00, &tramp[3]); |
| 174 | __put_user(0x05, &tramp[4]); |
| 175 | __put_user(0x00, &tramp[5]); |
| 176 | #else |
| 177 | /* Generate instruction: MOVI a2, __NR_rt_sigreturn */ |
| 178 | __put_user(0x22, &tramp[0]); |
| 179 | __put_user(0xa0, &tramp[1]); |
| 180 | __put_user(TARGET_NR_rt_sigreturn, &tramp[2]); |
| 181 | /* Generate instruction: SYSCALL */ |
| 182 | __put_user(0x00, &tramp[3]); |
| 183 | __put_user(0x50, &tramp[4]); |
| 184 | __put_user(0x00, &tramp[5]); |
| 185 | #endif |
| 186 | } |
| 187 | |
| 188 | void setup_rt_frame(int sig, struct target_sigaction *ka, |
| 189 | target_siginfo_t *info, |
| 190 | target_sigset_t *set, CPUXtensaState *env) |
| 191 | { |
| 192 | abi_ulong frame_addr; |
| 193 | struct target_rt_sigframe *frame; |
| 194 | int is_fdpic = info_is_fdpic(get_task_state(thread_cpu)->info); |
| 195 | abi_ulong handler = 0; |
| 196 | abi_ulong handler_fdpic_GOT = 0; |
| 197 | uint32_t ra; |
| 198 | bool abi_call0; |
| 199 | unsigned base; |
| 200 | int i; |
| 201 | |
| 202 | frame_addr = get_sigframe(ka, env, sizeof(*frame)); |
| 203 | trace_user_setup_rt_frame(env, frame_addr); |
| 204 | |
| 205 | if (is_fdpic) { |
| 206 | abi_ulong funcdesc_ptr = ka->_sa_handler; |
| 207 | |
| 208 | if (get_user_ual(handler, funcdesc_ptr) |
| 209 | || get_user_ual(handler_fdpic_GOT, funcdesc_ptr + 4)) { |
| 210 | goto give_sigsegv; |
| 211 | } |
| 212 | } else { |
| 213 | handler = ka->_sa_handler; |
| 214 | } |
| 215 | |
| 216 | if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) { |
| 217 | goto give_sigsegv; |
| 218 | } |
| 219 | |
| 220 | if (ka->sa_flags & SA_SIGINFO) { |
| 221 | frame->info = *info; |
| 222 | } |
| 223 | |
| 224 | __put_user(0, &frame->uc.tuc_flags); |
| 225 | __put_user(0, &frame->uc.tuc_link); |
| 226 | target_save_altstack(&frame->uc.tuc_stack, env); |
| 227 | if (!setup_sigcontext(frame, frame_addr, env)) { |
| 228 | unlock_user_struct(frame, frame_addr, 0); |
| 229 | goto give_sigsegv; |
| 230 | } |
| 231 | for (i = 0; i < TARGET_NSIG_WORDS; ++i) { |
| 232 | __put_user(set->sig[i], &frame->uc.tuc_sigmask.sig[i]); |
| 233 | } |
| 234 | |
| 235 | if (ka->sa_flags & TARGET_SA_RESTORER) { |
| 236 | if (is_fdpic) { |
| 237 | if (get_user_ual(ra, ka->sa_restorer)) { |
| 238 | unlock_user_struct(frame, frame_addr, 0); |
| 239 | goto give_sigsegv; |
| 240 | } |
| 241 | } else { |
| 242 | ra = ka->sa_restorer; |
| 243 | } |
| 244 | } else { |
| 245 | /* Not used, but retain for ABI compatibility. */ |
| 246 | install_sigtramp(frame->retcode); |
| 247 | ra = default_rt_sigreturn; |
| 248 | } |
| 249 | memset(env->regs, 0, sizeof(env->regs)); |
| 250 | env->pc = handler; |
| 251 | env->regs[1] = frame_addr; |
| 252 | env->sregs[WINDOW_BASE] = 0; |
| 253 | env->sregs[WINDOW_START] = 1; |
| 254 | |
| 255 | abi_call0 = (env->sregs[PS] & PS_WOE) == 0; |
| 256 | env->sregs[PS] = PS_UM | (3 << PS_RING_SHIFT); |
| 257 | |
| 258 | if (abi_call0) { |
| 259 | base = 0; |
| 260 | env->regs[base] = ra; |
| 261 | } else { |
| 262 | env->sregs[PS] |= PS_WOE | (1 << PS_CALLINC_SHIFT); |
| 263 | base = 4; |
| 264 | env->regs[base] = (ra & 0x3fffffff) | 0x40000000; |
| 265 | } |
| 266 | env->regs[base + 2] = sig; |
| 267 | env->regs[base + 3] = frame_addr + offsetof(struct target_rt_sigframe, |
| 268 | info); |
| 269 | env->regs[base + 4] = frame_addr + offsetof(struct target_rt_sigframe, uc); |
| 270 | if (is_fdpic) { |
| 271 | env->regs[base + 11] = handler_fdpic_GOT; |
| 272 | } |
| 273 | unlock_user_struct(frame, frame_addr, 1); |
| 274 | return; |
| 275 | |
| 276 | give_sigsegv: |
| 277 | force_sigsegv(sig); |
| 278 | } |
| 279 | |
| 280 | static int restore_sigcontext(CPUXtensaState *env, |
| 281 | struct target_rt_sigframe *frame) |
| 282 | { |
| 283 | struct target_sigcontext *sc = &frame->uc.tuc_mcontext; |
| 284 | uint32_t ps; |
| 285 | int i; |
| 286 | |
| 287 | __get_user(env->pc, &sc->sc_pc); |
| 288 | __get_user(ps, &sc->sc_ps); |
| 289 | __get_user(env->sregs[LBEG], &sc->sc_lbeg); |
| 290 | __get_user(env->sregs[LEND], &sc->sc_lend); |
| 291 | __get_user(env->sregs[LCOUNT], &sc->sc_lcount); |
| 292 | |
| 293 | env->sregs[WINDOW_BASE] = 0; |
| 294 | env->sregs[WINDOW_START] = 1; |
| 295 | env->sregs[PS] = deposit32(env->sregs[PS], |
| 296 | PS_CALLINC_SHIFT, |
| 297 | PS_CALLINC_LEN, |
| 298 | extract32(ps, PS_CALLINC_SHIFT, |
| 299 | PS_CALLINC_LEN)); |
| 300 | for (i = 0; i < 16; ++i) { |
| 301 | __get_user(env->regs[i], sc->sc_a + i); |
| 302 | } |
| 303 | { |
| 304 | abi_ulong xtregs_addr; |
| 305 | |
| 306 | __get_user(xtregs_addr, &sc->sc_xtregs); |
| 307 | if (xtregs_addr) { |
| 308 | if (xtensa_option_enabled(env->config, |
| 309 | XTENSA_OPTION_DFP_COPROCESSOR)) { |
| 310 | struct target_xtensa_xtregs_dfp *xtregs; |
| 311 | uint32_t fcr, fsr; |
| 312 | |
| 313 | xtregs = lock_user(VERIFY_READ, xtregs_addr, |
| 314 | sizeof(*xtregs), 1); |
| 315 | if (!xtregs) { |
| 316 | return 0; |
| 317 | } |
| 318 | for (i = 0; i < 16; ++i) { |
| 319 | __get_user(env->fregs[i].f64, &xtregs->f[i]); |
| 320 | } |
| 321 | __get_user(fcr, &xtregs->fcr); |
| 322 | __get_user(fsr, &xtregs->fsr); |
| 323 | unlock_user(xtregs, xtregs_addr, 0); |
| 324 | cpu_set_fcr(env, fcr); |
| 325 | cpu_set_fsr(env, fsr); |
| 326 | } else if (xtensa_option_enabled(env->config, |
| 327 | XTENSA_OPTION_FP_COPROCESSOR)) { |
| 328 | struct target_xtensa_xtregs_fp *xtregs; |
| 329 | uint32_t fcr, fsr; |
| 330 | |
| 331 | xtregs = lock_user(VERIFY_READ, xtregs_addr, |
| 332 | sizeof(*xtregs), 1); |
| 333 | if (!xtregs) { |
| 334 | return 0; |
| 335 | } |
| 336 | for (i = 0; i < 16; ++i) { |
| 337 | __get_user(env->fregs[i].f32[FP_F32_LOW], &xtregs->f[i]); |
| 338 | } |
| 339 | __get_user(fcr, &xtregs->fcr); |
| 340 | __get_user(fsr, &xtregs->fsr); |
| 341 | unlock_user(xtregs, xtregs_addr, 0); |
| 342 | cpu_set_fcr(env, fcr); |
| 343 | cpu_set_fsr(env, fsr); |
| 344 | } |
| 345 | } |
| 346 | } |
| 347 | return 1; |
| 348 | } |
| 349 | |
| 350 | long do_rt_sigreturn(CPUXtensaState *env) |
| 351 | { |
| 352 | abi_ulong frame_addr = env->regs[1]; |
| 353 | struct target_rt_sigframe *frame; |
| 354 | sigset_t set; |
| 355 | |
| 356 | trace_user_do_rt_sigreturn(env, frame_addr); |
| 357 | if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) { |
| 358 | force_sig(TARGET_SIGSEGV); |
| 359 | return -QEMU_ESIGRETURN; |
| 360 | } |
| 361 | target_to_host_sigset(&set, &frame->uc.tuc_sigmask); |
| 362 | set_sigmask(&set); |
| 363 | |
| 364 | if (!restore_sigcontext(env, frame)) { |
| 365 | goto badframe; |
| 366 | } |
| 367 | target_restore_altstack(&frame->uc.tuc_stack, env); |
| 368 | |
| 369 | unlock_user_struct(frame, frame_addr, 0); |
| 370 | return -QEMU_ESIGRETURN; |
| 371 | |
| 372 | badframe: |
| 373 | unlock_user_struct(frame, frame_addr, 0); |
| 374 | force_sig(TARGET_SIGSEGV); |
| 375 | return -QEMU_ESIGRETURN; |
| 376 | } |
| 377 | |
| 378 | void setup_sigtramp(abi_ulong sigtramp_page) |
| 379 | { |
| 380 | uint8_t *tramp = lock_user(VERIFY_WRITE, sigtramp_page, 6, 0); |
| 381 | assert(tramp != NULL); |
| 382 | |
| 383 | default_rt_sigreturn = sigtramp_page; |
| 384 | install_sigtramp(tramp); |
| 385 | unlock_user(tramp, sigtramp_page, 6); |
| 386 | } |