| 1 | /* SPDX-License-Identifier: GPL-2.0-or-later */ |
| 2 | /* |
| 3 | * LoongArch emulation of Linux signals |
| 4 | * |
| 5 | * Copyright (c) 2021 Loongson Technology Corporation Limited |
| 6 | */ |
| 7 | |
| 8 | #include "qemu/osdep.h" |
| 9 | #include "qemu.h" |
| 10 | #include "user-internals.h" |
| 11 | #include "signal-common.h" |
| 12 | #include "linux-user/trace.h" |
| 13 | #include "target/loongarch/internals.h" |
| 14 | #include "target/loongarch/vec.h" |
| 15 | #include "vdso-asmoffset.h" |
| 16 | |
| 17 | /* FP context was used */ |
| 18 | #define SC_USED_FP (1 << 0) |
| 19 | |
| 20 | struct target_sigcontext { |
| 21 | abi_ulong sc_pc; |
| 22 | abi_ulong sc_regs[32]; |
| 23 | abi_uint sc_flags; |
| 24 | abi_ulong sc_extcontext[0] QEMU_ALIGNED(16); |
| 25 | }; |
| 26 | |
| 27 | QEMU_BUILD_BUG_ON(sizeof(struct target_sigcontext) != sizeof_sigcontext); |
| 28 | QEMU_BUILD_BUG_ON(offsetof(struct target_sigcontext, sc_pc) |
| 29 | != offsetof_sigcontext_pc); |
| 30 | QEMU_BUILD_BUG_ON(offsetof(struct target_sigcontext, sc_regs) |
| 31 | != offsetof_sigcontext_gr); |
| 32 | |
| 33 | #define FPU_CTX_MAGIC 0x46505501 |
| 34 | #define FPU_CTX_ALIGN 8 |
| 35 | struct target_fpu_context { |
| 36 | abi_ulong regs[32]; |
| 37 | abi_ulong fcc; |
| 38 | abi_uint fcsr; |
| 39 | } QEMU_ALIGNED(FPU_CTX_ALIGN); |
| 40 | |
| 41 | QEMU_BUILD_BUG_ON(offsetof(struct target_fpu_context, regs) |
| 42 | != offsetof_fpucontext_fr); |
| 43 | |
| 44 | #define LSX_CTX_MAGIC 0x53580001 |
| 45 | #define LSX_CTX_ALIGN 16 |
| 46 | struct target_lsx_context { |
| 47 | abi_ulong regs[2 * 32]; |
| 48 | abi_ulong fcc; |
| 49 | abi_uint fcsr; |
| 50 | } QEMU_ALIGNED(LSX_CTX_ALIGN); |
| 51 | |
| 52 | #define LASX_CTX_MAGIC 0x41535801 |
| 53 | #define LASX_CTX_ALIGN 32 |
| 54 | struct target_lasx_context { |
| 55 | abi_ulong regs[4 * 32]; |
| 56 | abi_ulong fcc; |
| 57 | abi_uint fcsr; |
| 58 | } QEMU_ALIGNED(LASX_CTX_ALIGN); |
| 59 | |
| 60 | #define CONTEXT_INFO_ALIGN 16 |
| 61 | struct target_sctx_info { |
| 62 | abi_uint magic; |
| 63 | abi_uint size; |
| 64 | abi_ulong padding; |
| 65 | } QEMU_ALIGNED(CONTEXT_INFO_ALIGN); |
| 66 | |
| 67 | QEMU_BUILD_BUG_ON(sizeof(struct target_sctx_info) != sizeof_sctx_info); |
| 68 | |
| 69 | struct target_ucontext { |
| 70 | abi_ulong tuc_flags; |
| 71 | abi_ptr tuc_link; |
| 72 | target_stack_t tuc_stack; |
| 73 | target_sigset_t tuc_sigmask; |
| 74 | uint8_t __unused[1024 / 8 - sizeof(target_sigset_t)]; |
| 75 | struct target_sigcontext tuc_mcontext; |
| 76 | }; |
| 77 | |
| 78 | struct target_rt_sigframe { |
| 79 | struct target_siginfo rs_info; |
| 80 | struct target_ucontext rs_uc; |
| 81 | }; |
| 82 | |
| 83 | QEMU_BUILD_BUG_ON(sizeof(struct target_rt_sigframe) |
| 84 | != sizeof_rt_sigframe); |
| 85 | QEMU_BUILD_BUG_ON(offsetof(struct target_rt_sigframe, rs_uc.tuc_mcontext) |
| 86 | != offsetof_sigcontext); |
| 87 | |
| 88 | /* |
| 89 | * These two structures are not present in guest memory, are private |
| 90 | * to the signal implementation, but are largely copied from the |
| 91 | * kernel's signal implementation. |
| 92 | */ |
| 93 | struct ctx_layout { |
| 94 | void *haddr; |
| 95 | abi_ptr gaddr; |
| 96 | unsigned int size; |
| 97 | }; |
| 98 | |
| 99 | struct extctx_layout { |
| 100 | unsigned long size; |
| 101 | unsigned int flags; |
| 102 | struct ctx_layout fpu; |
| 103 | struct ctx_layout lsx; |
| 104 | struct ctx_layout lasx; |
| 105 | struct ctx_layout end; |
| 106 | }; |
| 107 | |
| 108 | static abi_ptr extframe_alloc(struct extctx_layout *extctx, |
| 109 | struct ctx_layout *sctx, unsigned size, |
| 110 | unsigned align, abi_ptr orig_sp) |
| 111 | { |
| 112 | abi_ptr sp = orig_sp; |
| 113 | |
| 114 | sp -= sizeof(struct target_sctx_info) + size; |
| 115 | align = MAX(align, CONTEXT_INFO_ALIGN); |
| 116 | sp = ROUND_DOWN(sp, align); |
| 117 | sctx->gaddr = sp; |
| 118 | |
| 119 | size = orig_sp - sp; |
| 120 | sctx->size = size; |
| 121 | extctx->size += size; |
| 122 | |
| 123 | return sp; |
| 124 | } |
| 125 | |
| 126 | static abi_ptr setup_extcontext(CPULoongArchState *env, |
| 127 | struct extctx_layout *extctx, abi_ptr sp) |
| 128 | { |
| 129 | CPUSysState *sys = env_sys(env); |
| 130 | |
| 131 | memset(extctx, 0, sizeof(struct extctx_layout)); |
| 132 | |
| 133 | /* Grow down, alloc "end" context info first. */ |
| 134 | sp = extframe_alloc(extctx, &extctx->end, 0, CONTEXT_INFO_ALIGN, sp); |
| 135 | |
| 136 | /* For qemu, there is no lazy fp context switch, so fp always present. */ |
| 137 | extctx->flags = SC_USED_FP; |
| 138 | |
| 139 | if (FIELD_EX64(sys->CSR_EUEN, CSR_EUEN, ASXE)) { |
| 140 | sp = extframe_alloc(extctx, &extctx->lasx, |
| 141 | sizeof(struct target_lasx_context), LASX_CTX_ALIGN, sp); |
| 142 | } else if (FIELD_EX64(sys->CSR_EUEN, CSR_EUEN, SXE)) { |
| 143 | sp = extframe_alloc(extctx, &extctx->lsx, |
| 144 | sizeof(struct target_lsx_context), LSX_CTX_ALIGN, sp); |
| 145 | } else { |
| 146 | sp = extframe_alloc(extctx, &extctx->fpu, |
| 147 | sizeof(struct target_fpu_context), FPU_CTX_ALIGN, sp); |
| 148 | } |
| 149 | |
| 150 | return sp; |
| 151 | } |
| 152 | |
| 153 | static void setup_sigframe(CPULoongArchState *env, |
| 154 | struct target_sigcontext *sc, |
| 155 | struct extctx_layout *extctx) |
| 156 | { |
| 157 | CPUSysState *sys = env_sys(env); |
| 158 | struct target_sctx_info *info; |
| 159 | int i; |
| 160 | |
| 161 | __put_user(extctx->flags, &sc->sc_flags); |
| 162 | __put_user(env->pc, &sc->sc_pc); |
| 163 | __put_user(0, &sc->sc_regs[0]); |
| 164 | for (i = 1; i < 32; ++i) { |
| 165 | __put_user(env->gpr[i], &sc->sc_regs[i]); |
| 166 | } |
| 167 | |
| 168 | /* |
| 169 | * Set extension context |
| 170 | */ |
| 171 | |
| 172 | if (FIELD_EX64(sys->CSR_EUEN, CSR_EUEN, ASXE)) { |
| 173 | struct target_lasx_context *lasx_ctx; |
| 174 | info = extctx->lasx.haddr; |
| 175 | |
| 176 | __put_user(LASX_CTX_MAGIC, &info->magic); |
| 177 | __put_user(extctx->lasx.size, &info->size); |
| 178 | |
| 179 | lasx_ctx = (struct target_lasx_context *)(info + 1); |
| 180 | |
| 181 | for (i = 0; i < 32; ++i) { |
| 182 | __put_user(env->fpr[i].vreg.UD(0), &lasx_ctx->regs[4 * i]); |
| 183 | __put_user(env->fpr[i].vreg.UD(1), &lasx_ctx->regs[4 * i + 1]); |
| 184 | __put_user(env->fpr[i].vreg.UD(2), &lasx_ctx->regs[4 * i + 2]); |
| 185 | __put_user(env->fpr[i].vreg.UD(3), &lasx_ctx->regs[4 * i + 3]); |
| 186 | } |
| 187 | __put_user(read_fcc(env), &lasx_ctx->fcc); |
| 188 | __put_user(env->fcsr0, &lasx_ctx->fcsr); |
| 189 | } else if (FIELD_EX64(sys->CSR_EUEN, CSR_EUEN, SXE)) { |
| 190 | struct target_lsx_context *lsx_ctx; |
| 191 | info = extctx->lsx.haddr; |
| 192 | |
| 193 | __put_user(LSX_CTX_MAGIC, &info->magic); |
| 194 | __put_user(extctx->lsx.size, &info->size); |
| 195 | |
| 196 | lsx_ctx = (struct target_lsx_context *)(info + 1); |
| 197 | |
| 198 | for (i = 0; i < 32; ++i) { |
| 199 | __put_user(env->fpr[i].vreg.UD(0), &lsx_ctx->regs[2 * i]); |
| 200 | __put_user(env->fpr[i].vreg.UD(1), &lsx_ctx->regs[2 * i + 1]); |
| 201 | } |
| 202 | __put_user(read_fcc(env), &lsx_ctx->fcc); |
| 203 | __put_user(env->fcsr0, &lsx_ctx->fcsr); |
| 204 | } else { |
| 205 | struct target_fpu_context *fpu_ctx; |
| 206 | info = extctx->fpu.haddr; |
| 207 | |
| 208 | __put_user(FPU_CTX_MAGIC, &info->magic); |
| 209 | __put_user(extctx->fpu.size, &info->size); |
| 210 | |
| 211 | fpu_ctx = (struct target_fpu_context *)(info + 1); |
| 212 | |
| 213 | for (i = 0; i < 32; ++i) { |
| 214 | __put_user(env->fpr[i].vreg.UD(0), &fpu_ctx->regs[i]); |
| 215 | } |
| 216 | __put_user(read_fcc(env), &fpu_ctx->fcc); |
| 217 | __put_user(env->fcsr0, &fpu_ctx->fcsr); |
| 218 | } |
| 219 | |
| 220 | /* |
| 221 | * Set end context |
| 222 | */ |
| 223 | info = extctx->end.haddr; |
| 224 | __put_user(0, &info->magic); |
| 225 | __put_user(0, &info->size); |
| 226 | } |
| 227 | |
| 228 | static bool parse_extcontext(struct extctx_layout *extctx, abi_ptr frame) |
| 229 | { |
| 230 | memset(extctx, 0, sizeof(*extctx)); |
| 231 | |
| 232 | while (1) { |
| 233 | abi_uint magic, size; |
| 234 | |
| 235 | if (get_user_u32(magic, frame) || get_user_u32(size, frame + 4)) { |
| 236 | return false; |
| 237 | } |
| 238 | |
| 239 | switch (magic) { |
| 240 | case 0: /* END */ |
| 241 | extctx->end.gaddr = frame; |
| 242 | extctx->end.size = size; |
| 243 | extctx->size += size; |
| 244 | return true; |
| 245 | |
| 246 | case FPU_CTX_MAGIC: |
| 247 | if (size < (sizeof(struct target_sctx_info) + |
| 248 | sizeof(struct target_fpu_context))) { |
| 249 | return false; |
| 250 | } |
| 251 | extctx->fpu.gaddr = frame; |
| 252 | extctx->fpu.size = size; |
| 253 | extctx->size += size; |
| 254 | break; |
| 255 | case LSX_CTX_MAGIC: |
| 256 | if (size < (sizeof(struct target_sctx_info) + |
| 257 | sizeof(struct target_lsx_context))) { |
| 258 | return false; |
| 259 | } |
| 260 | extctx->lsx.gaddr = frame; |
| 261 | extctx->lsx.size = size; |
| 262 | extctx->size += size; |
| 263 | break; |
| 264 | case LASX_CTX_MAGIC: |
| 265 | if (size < (sizeof(struct target_sctx_info) + |
| 266 | sizeof(struct target_lasx_context))) { |
| 267 | return false; |
| 268 | } |
| 269 | extctx->lasx.gaddr = frame; |
| 270 | extctx->lasx.size = size; |
| 271 | extctx->size += size; |
| 272 | break; |
| 273 | default: |
| 274 | return false; |
| 275 | } |
| 276 | |
| 277 | frame += size; |
| 278 | } |
| 279 | } |
| 280 | |
| 281 | static void restore_sigframe(CPULoongArchState *env, |
| 282 | struct target_sigcontext *sc, |
| 283 | struct extctx_layout *extctx) |
| 284 | { |
| 285 | int i; |
| 286 | abi_ulong fcc; |
| 287 | |
| 288 | __get_user(env->pc, &sc->sc_pc); |
| 289 | for (i = 1; i < 32; ++i) { |
| 290 | __get_user(env->gpr[i], &sc->sc_regs[i]); |
| 291 | } |
| 292 | |
| 293 | if (extctx->lasx.haddr) { |
| 294 | struct target_lasx_context *lasx_ctx = |
| 295 | extctx->lasx.haddr + sizeof(struct target_sctx_info); |
| 296 | |
| 297 | for (i = 0; i < 32; ++i) { |
| 298 | __get_user(env->fpr[i].vreg.UD(0), &lasx_ctx->regs[4 * i]); |
| 299 | __get_user(env->fpr[i].vreg.UD(1), &lasx_ctx->regs[4 * i + 1]); |
| 300 | __get_user(env->fpr[i].vreg.UD(2), &lasx_ctx->regs[4 * i + 2]); |
| 301 | __get_user(env->fpr[i].vreg.UD(3), &lasx_ctx->regs[4 * i + 3]); |
| 302 | } |
| 303 | __get_user(fcc, &lasx_ctx->fcc); |
| 304 | write_fcc(env, fcc); |
| 305 | __get_user(env->fcsr0, &lasx_ctx->fcsr); |
| 306 | restore_fp_status(env); |
| 307 | } else if (extctx->lsx.haddr) { |
| 308 | struct target_lsx_context *lsx_ctx = |
| 309 | extctx->lsx.haddr + sizeof(struct target_sctx_info); |
| 310 | |
| 311 | for (i = 0; i < 32; ++i) { |
| 312 | __get_user(env->fpr[i].vreg.UD(0), &lsx_ctx->regs[2 * i]); |
| 313 | __get_user(env->fpr[i].vreg.UD(1), &lsx_ctx->regs[2 * i + 1]); |
| 314 | } |
| 315 | __get_user(fcc, &lsx_ctx->fcc); |
| 316 | write_fcc(env, fcc); |
| 317 | __get_user(env->fcsr0, &lsx_ctx->fcsr); |
| 318 | restore_fp_status(env); |
| 319 | } else if (extctx->fpu.haddr) { |
| 320 | struct target_fpu_context *fpu_ctx = |
| 321 | extctx->fpu.haddr + sizeof(struct target_sctx_info); |
| 322 | |
| 323 | for (i = 0; i < 32; ++i) { |
| 324 | __get_user(env->fpr[i].vreg.UD(0), &fpu_ctx->regs[i]); |
| 325 | } |
| 326 | __get_user(fcc, &fpu_ctx->fcc); |
| 327 | write_fcc(env, fcc); |
| 328 | __get_user(env->fcsr0, &fpu_ctx->fcsr); |
| 329 | restore_fp_status(env); |
| 330 | } |
| 331 | } |
| 332 | |
| 333 | /* |
| 334 | * Determine which stack to use. |
| 335 | */ |
| 336 | static abi_ptr get_sigframe(struct target_sigaction *ka, |
| 337 | CPULoongArchState *env, |
| 338 | struct extctx_layout *extctx) |
| 339 | { |
| 340 | abi_ulong sp; |
| 341 | |
| 342 | sp = target_sigsp(get_sp_from_cpustate(env), ka); |
| 343 | sp = ROUND_DOWN(sp, 16); |
| 344 | sp = setup_extcontext(env, extctx, sp); |
| 345 | sp -= sizeof(struct target_rt_sigframe); |
| 346 | |
| 347 | assert(QEMU_IS_ALIGNED(sp, 16)); |
| 348 | |
| 349 | return sp; |
| 350 | } |
| 351 | |
| 352 | void setup_rt_frame(int sig, struct target_sigaction *ka, |
| 353 | target_siginfo_t *info, |
| 354 | target_sigset_t *set, CPULoongArchState *env) |
| 355 | { |
| 356 | CPUSysState *sys = env_sys(env); |
| 357 | struct target_rt_sigframe *frame; |
| 358 | struct extctx_layout extctx; |
| 359 | abi_ptr frame_addr; |
| 360 | int i; |
| 361 | |
| 362 | frame_addr = get_sigframe(ka, env, &extctx); |
| 363 | trace_user_setup_rt_frame(env, frame_addr); |
| 364 | |
| 365 | frame = lock_user(VERIFY_WRITE, frame_addr, |
| 366 | sizeof(*frame) + extctx.size, 0); |
| 367 | if (!frame) { |
| 368 | force_sigsegv(sig); |
| 369 | return; |
| 370 | } |
| 371 | |
| 372 | if (FIELD_EX64(sys->CSR_EUEN, CSR_EUEN, ASXE)) { |
| 373 | extctx.lasx.haddr = (void *)frame + (extctx.lasx.gaddr - frame_addr); |
| 374 | extctx.end.haddr = (void *)frame + (extctx.end.gaddr - frame_addr); |
| 375 | } else if (FIELD_EX64(sys->CSR_EUEN, CSR_EUEN, SXE)) { |
| 376 | extctx.lsx.haddr = (void *)frame + (extctx.lsx.gaddr - frame_addr); |
| 377 | extctx.end.haddr = (void *)frame + (extctx.end.gaddr - frame_addr); |
| 378 | } else { |
| 379 | extctx.fpu.haddr = (void *)frame + (extctx.fpu.gaddr - frame_addr); |
| 380 | extctx.end.haddr = (void *)frame + (extctx.end.gaddr - frame_addr); |
| 381 | } |
| 382 | |
| 383 | frame->rs_info = *info; |
| 384 | |
| 385 | __put_user(0, &frame->rs_uc.tuc_flags); |
| 386 | __put_user(0, &frame->rs_uc.tuc_link); |
| 387 | target_save_altstack(&frame->rs_uc.tuc_stack, env); |
| 388 | |
| 389 | setup_sigframe(env, &frame->rs_uc.tuc_mcontext, &extctx); |
| 390 | |
| 391 | for (i = 0; i < TARGET_NSIG_WORDS; i++) { |
| 392 | __put_user(set->sig[i], &frame->rs_uc.tuc_sigmask.sig[i]); |
| 393 | } |
| 394 | |
| 395 | env->gpr[4] = sig; |
| 396 | env->gpr[5] = frame_addr + offsetof(struct target_rt_sigframe, rs_info); |
| 397 | env->gpr[6] = frame_addr + offsetof(struct target_rt_sigframe, rs_uc); |
| 398 | env->gpr[3] = frame_addr; |
| 399 | env->gpr[1] = default_rt_sigreturn; |
| 400 | |
| 401 | env->pc = ka->_sa_handler; |
| 402 | unlock_user(frame, frame_addr, sizeof(*frame) + extctx.size); |
| 403 | } |
| 404 | |
| 405 | long do_rt_sigreturn(CPULoongArchState *env) |
| 406 | { |
| 407 | struct target_rt_sigframe *frame; |
| 408 | struct extctx_layout extctx; |
| 409 | abi_ulong frame_addr; |
| 410 | sigset_t blocked; |
| 411 | |
| 412 | frame_addr = env->gpr[3]; |
| 413 | trace_user_do_rt_sigreturn(env, frame_addr); |
| 414 | |
| 415 | if (!parse_extcontext(&extctx, frame_addr + sizeof(*frame))) { |
| 416 | goto badframe; |
| 417 | } |
| 418 | |
| 419 | frame = lock_user(VERIFY_READ, frame_addr, |
| 420 | sizeof(*frame) + extctx.size, 1); |
| 421 | if (!frame) { |
| 422 | goto badframe; |
| 423 | } |
| 424 | |
| 425 | if (extctx.lasx.gaddr) { |
| 426 | extctx.lasx.haddr = (void *)frame + (extctx.lasx.gaddr - frame_addr); |
| 427 | } else if (extctx.lsx.gaddr) { |
| 428 | extctx.lsx.haddr = (void *)frame + (extctx.lsx.gaddr - frame_addr); |
| 429 | } else if (extctx.fpu.gaddr) { |
| 430 | extctx.fpu.haddr = (void *)frame + (extctx.fpu.gaddr - frame_addr); |
| 431 | } |
| 432 | |
| 433 | target_to_host_sigset(&blocked, &frame->rs_uc.tuc_sigmask); |
| 434 | set_sigmask(&blocked); |
| 435 | |
| 436 | restore_sigframe(env, &frame->rs_uc.tuc_mcontext, &extctx); |
| 437 | |
| 438 | target_restore_altstack(&frame->rs_uc.tuc_stack, env); |
| 439 | |
| 440 | unlock_user(frame, frame_addr, 0); |
| 441 | return -QEMU_ESIGRETURN; |
| 442 | |
| 443 | badframe: |
| 444 | force_sig(TARGET_SIGSEGV); |
| 445 | return -QEMU_ESIGRETURN; |
| 446 | } |
| 447 | |
| 448 | void setup_sigtramp(abi_ulong sigtramp_page) |
| 449 | { |
| 450 | uint32_t *tramp = lock_user(VERIFY_WRITE, sigtramp_page, 8, 0); |
| 451 | assert(tramp != NULL); |
| 452 | |
| 453 | __put_user(0x03822c0b, tramp + 0); /* ori a7, zero, 0x8b */ |
| 454 | __put_user(0x002b0000, tramp + 1); /* syscall 0 */ |
| 455 | |
| 456 | default_rt_sigreturn = sigtramp_page; |
| 457 | unlock_user(tramp, sigtramp_page, 8); |
| 458 | } |