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 struct target_sigcontext { 26 uint64_t fault_address; 27 /* AArch64 registers */ 28 uint64_t regs[31]; 29 uint64_t sp; 30 uint64_t pc; 31 uint64_t pstate; 32 /* 4K reserved for FP/SIMD state and future expansion */ 33 char __reserved[4096] __attribute__((__aligned__(16))); 34 }; 35 36 struct target_ucontext { 37 abi_ulong tuc_flags; 38 abi_ulong tuc_link; 39 target_stack_t tuc_stack; 40 target_sigset_t tuc_sigmask; 41 /* glibc uses a 1024-bit sigset_t */ 42 char __unused[1024 / 8 - sizeof(target_sigset_t)]; 43 /* last for future expansion */ 44 struct target_sigcontext tuc_mcontext; 45 }; 46 47 /* 48 * Header to be used at the beginning of structures extending the user 49 * context. Such structures must be placed after the rt_sigframe on the stack 50 * and be 16-byte aligned. The last structure must be a dummy one with the 51 * magic and size set to 0. 52 */ 53 struct target_aarch64_ctx { 54 uint32_t magic; 55 uint32_t size; 56 }; 57 58 #define TARGET_FPSIMD_MAGIC 0x46508001 59 60 struct target_fpsimd_context { 61 struct target_aarch64_ctx head; 62 uint32_t fpsr; 63 uint32_t fpcr; 64 uint64_t vregs[32 * 2]; /* really uint128_t vregs[32] */ 65 }; 66 67 #define TARGET_EXTRA_MAGIC 0x45585401 68 69 struct target_extra_context { 70 struct target_aarch64_ctx head; 71 uint64_t datap; /* 16-byte aligned pointer to extra space cast to __u64 */ 72 uint32_t size; /* size in bytes of the extra space */ 73 uint32_t reserved[3]; 74 }; 75 76 #define TARGET_SVE_MAGIC 0x53564501 77 78 struct target_sve_context { 79 struct target_aarch64_ctx head; 80 uint16_t vl; 81 uint16_t flags; 82 uint16_t reserved[2]; 83 /* The actual SVE data immediately follows. It is laid out 84 * according to TARGET_SVE_SIG_{Z,P}REG_OFFSET, based off of 85 * the original struct pointer. 86 */ 87 }; 88 89 #define TARGET_SVE_VQ_BYTES 16 90 91 #define TARGET_SVE_SIG_ZREG_SIZE(VQ) ((VQ) * TARGET_SVE_VQ_BYTES) 92 #define TARGET_SVE_SIG_PREG_SIZE(VQ) ((VQ) * (TARGET_SVE_VQ_BYTES / 8)) 93 94 #define TARGET_SVE_SIG_REGS_OFFSET \ 95 QEMU_ALIGN_UP(sizeof(struct target_sve_context), TARGET_SVE_VQ_BYTES) 96 #define TARGET_SVE_SIG_ZREG_OFFSET(VQ, N) \ 97 (TARGET_SVE_SIG_REGS_OFFSET + TARGET_SVE_SIG_ZREG_SIZE(VQ) * (N)) 98 #define TARGET_SVE_SIG_PREG_OFFSET(VQ, N) \ 99 (TARGET_SVE_SIG_ZREG_OFFSET(VQ, 32) + TARGET_SVE_SIG_PREG_SIZE(VQ) * (N)) 100 #define TARGET_SVE_SIG_FFR_OFFSET(VQ) \ 101 (TARGET_SVE_SIG_PREG_OFFSET(VQ, 16)) 102 #define TARGET_SVE_SIG_CONTEXT_SIZE(VQ) \ 103 (TARGET_SVE_SIG_PREG_OFFSET(VQ, 17)) 104 105 #define TARGET_SVE_SIG_FLAG_SM 1 106 107 struct target_rt_sigframe { 108 struct target_siginfo info; 109 struct target_ucontext uc; 110 }; 111 112 struct target_rt_frame_record { 113 uint64_t fp; 114 uint64_t lr; 115 }; 116 117 static void target_setup_general_frame(struct target_rt_sigframe *sf, 118 CPUARMState *env, target_sigset_t *set) 119 { 120 int i; 121 122 __put_user(0, &sf->uc.tuc_flags); 123 __put_user(0, &sf->uc.tuc_link); 124 125 target_save_altstack(&sf->uc.tuc_stack, env); 126 127 for (i = 0; i < 31; i++) { 128 __put_user(env->xregs[i], &sf->uc.tuc_mcontext.regs[i]); 129 } 130 __put_user(env->xregs[31], &sf->uc.tuc_mcontext.sp); 131 __put_user(env->pc, &sf->uc.tuc_mcontext.pc); 132 __put_user(pstate_read(env), &sf->uc.tuc_mcontext.pstate); 133 134 __put_user(env->exception.vaddress, &sf->uc.tuc_mcontext.fault_address); 135 136 for (i = 0; i < TARGET_NSIG_WORDS; i++) { 137 __put_user(set->sig[i], &sf->uc.tuc_sigmask.sig[i]); 138 } 139 } 140 141 static void target_setup_fpsimd_record(struct target_fpsimd_context *fpsimd, 142 CPUARMState *env) 143 { 144 int i; 145 146 __put_user(TARGET_FPSIMD_MAGIC, &fpsimd->head.magic); 147 __put_user(sizeof(struct target_fpsimd_context), &fpsimd->head.size); 148 __put_user(vfp_get_fpsr(env), &fpsimd->fpsr); 149 __put_user(vfp_get_fpcr(env), &fpsimd->fpcr); 150 151 for (i = 0; i < 32; i++) { 152 uint64_t *q = aa64_vfp_qreg(env, i); 153 #if TARGET_BIG_ENDIAN 154 __put_user(q[0], &fpsimd->vregs[i * 2 + 1]); 155 __put_user(q[1], &fpsimd->vregs[i * 2]); 156 #else 157 __put_user(q[0], &fpsimd->vregs[i * 2]); 158 __put_user(q[1], &fpsimd->vregs[i * 2 + 1]); 159 #endif 160 } 161 } 162 163 static void target_setup_extra_record(struct target_extra_context *extra, 164 uint64_t datap, uint32_t extra_size) 165 { 166 __put_user(TARGET_EXTRA_MAGIC, &extra->head.magic); 167 __put_user(sizeof(struct target_extra_context), &extra->head.size); 168 __put_user(datap, &extra->datap); 169 __put_user(extra_size, &extra->size); 170 } 171 172 static void target_setup_end_record(struct target_aarch64_ctx *end) 173 { 174 __put_user(0, &end->magic); 175 __put_user(0, &end->size); 176 } 177 178 static void target_setup_sve_record(struct target_sve_context *sve, 179 CPUARMState *env, int vq, int size) 180 { 181 int i, j; 182 183 memset(sve, 0, sizeof(*sve)); 184 __put_user(TARGET_SVE_MAGIC, &sve->head.magic); 185 __put_user(size, &sve->head.size); 186 __put_user(vq * TARGET_SVE_VQ_BYTES, &sve->vl); 187 if (FIELD_EX64(env->svcr, SVCR, SM)) { 188 __put_user(TARGET_SVE_SIG_FLAG_SM, &sve->flags); 189 } 190 191 /* Note that SVE regs are stored as a byte stream, with each byte element 192 * at a subsequent address. This corresponds to a little-endian store 193 * of our 64-bit hunks. 194 */ 195 for (i = 0; i < 32; ++i) { 196 uint64_t *z = (void *)sve + TARGET_SVE_SIG_ZREG_OFFSET(vq, i); 197 for (j = 0; j < vq * 2; ++j) { 198 __put_user_e(env->vfp.zregs[i].d[j], z + j, le); 199 } 200 } 201 for (i = 0; i <= 16; ++i) { 202 uint16_t *p = (void *)sve + TARGET_SVE_SIG_PREG_OFFSET(vq, i); 203 for (j = 0; j < vq; ++j) { 204 uint64_t r = env->vfp.pregs[i].p[j >> 2]; 205 __put_user_e(r >> ((j & 3) * 16), p + j, le); 206 } 207 } 208 } 209 210 static void target_restore_general_frame(CPUARMState *env, 211 struct target_rt_sigframe *sf) 212 { 213 sigset_t set; 214 uint64_t pstate; 215 int i; 216 217 target_to_host_sigset(&set, &sf->uc.tuc_sigmask); 218 set_sigmask(&set); 219 220 for (i = 0; i < 31; i++) { 221 __get_user(env->xregs[i], &sf->uc.tuc_mcontext.regs[i]); 222 } 223 224 __get_user(env->xregs[31], &sf->uc.tuc_mcontext.sp); 225 __get_user(env->pc, &sf->uc.tuc_mcontext.pc); 226 __get_user(pstate, &sf->uc.tuc_mcontext.pstate); 227 pstate_write(env, pstate); 228 } 229 230 static void target_restore_fpsimd_record(CPUARMState *env, 231 struct target_fpsimd_context *fpsimd) 232 { 233 uint32_t fpsr, fpcr; 234 int i; 235 236 __get_user(fpsr, &fpsimd->fpsr); 237 vfp_set_fpsr(env, fpsr); 238 __get_user(fpcr, &fpsimd->fpcr); 239 vfp_set_fpcr(env, fpcr); 240 241 for (i = 0; i < 32; i++) { 242 uint64_t *q = aa64_vfp_qreg(env, i); 243 #if TARGET_BIG_ENDIAN 244 __get_user(q[0], &fpsimd->vregs[i * 2 + 1]); 245 __get_user(q[1], &fpsimd->vregs[i * 2]); 246 #else 247 __get_user(q[0], &fpsimd->vregs[i * 2]); 248 __get_user(q[1], &fpsimd->vregs[i * 2 + 1]); 249 #endif 250 } 251 } 252 253 static void target_restore_sve_record(CPUARMState *env, 254 struct target_sve_context *sve, int vq) 255 { 256 int i, j; 257 258 /* Note that SVE regs are stored as a byte stream, with each byte element 259 * at a subsequent address. This corresponds to a little-endian load 260 * of our 64-bit hunks. 261 */ 262 for (i = 0; i < 32; ++i) { 263 uint64_t *z = (void *)sve + TARGET_SVE_SIG_ZREG_OFFSET(vq, i); 264 for (j = 0; j < vq * 2; ++j) { 265 __get_user_e(env->vfp.zregs[i].d[j], z + j, le); 266 } 267 } 268 for (i = 0; i <= 16; ++i) { 269 uint16_t *p = (void *)sve + TARGET_SVE_SIG_PREG_OFFSET(vq, i); 270 for (j = 0; j < vq; ++j) { 271 uint16_t r; 272 __get_user_e(r, p + j, le); 273 if (j & 3) { 274 env->vfp.pregs[i].p[j >> 2] |= (uint64_t)r << ((j & 3) * 16); 275 } else { 276 env->vfp.pregs[i].p[j >> 2] = r; 277 } 278 } 279 } 280 } 281 282 static int target_restore_sigframe(CPUARMState *env, 283 struct target_rt_sigframe *sf) 284 { 285 struct target_aarch64_ctx *ctx, *extra = NULL; 286 struct target_fpsimd_context *fpsimd = NULL; 287 struct target_sve_context *sve = NULL; 288 uint64_t extra_datap = 0; 289 bool used_extra = false; 290 int vq = 0, sve_size = 0; 291 292 target_restore_general_frame(env, sf); 293 294 ctx = (struct target_aarch64_ctx *)sf->uc.tuc_mcontext.__reserved; 295 while (ctx) { 296 uint32_t magic, size, extra_size; 297 298 __get_user(magic, &ctx->magic); 299 __get_user(size, &ctx->size); 300 switch (magic) { 301 case 0: 302 if (size != 0) { 303 goto err; 304 } 305 if (used_extra) { 306 ctx = NULL; 307 } else { 308 ctx = extra; 309 used_extra = true; 310 } 311 continue; 312 313 case TARGET_FPSIMD_MAGIC: 314 if (fpsimd || size != sizeof(struct target_fpsimd_context)) { 315 goto err; 316 } 317 fpsimd = (struct target_fpsimd_context *)ctx; 318 break; 319 320 case TARGET_SVE_MAGIC: 321 if (sve || size < sizeof(struct target_sve_context)) { 322 goto err; 323 } 324 if (cpu_isar_feature(aa64_sve, env_archcpu(env))) { 325 vq = sve_vq(env); 326 sve_size = QEMU_ALIGN_UP(TARGET_SVE_SIG_CONTEXT_SIZE(vq), 16); 327 if (size == sve_size) { 328 sve = (struct target_sve_context *)ctx; 329 break; 330 } 331 } 332 goto err; 333 334 case TARGET_EXTRA_MAGIC: 335 if (extra || size != sizeof(struct target_extra_context)) { 336 goto err; 337 } 338 __get_user(extra_datap, 339 &((struct target_extra_context *)ctx)->datap); 340 __get_user(extra_size, 341 &((struct target_extra_context *)ctx)->size); 342 extra = lock_user(VERIFY_READ, extra_datap, extra_size, 0); 343 if (!extra) { 344 return 1; 345 } 346 break; 347 348 default: 349 /* Unknown record -- we certainly didn't generate it. 350 * Did we in fact get out of sync? 351 */ 352 goto err; 353 } 354 ctx = (void *)ctx + size; 355 } 356 357 /* Require FPSIMD always. */ 358 if (fpsimd) { 359 target_restore_fpsimd_record(env, fpsimd); 360 } else { 361 goto err; 362 } 363 364 /* SVE data, if present, overwrites FPSIMD data. */ 365 if (sve) { 366 target_restore_sve_record(env, sve, vq); 367 } 368 unlock_user(extra, extra_datap, 0); 369 return 0; 370 371 err: 372 unlock_user(extra, extra_datap, 0); 373 return 1; 374 } 375 376 static abi_ulong get_sigframe(struct target_sigaction *ka, 377 CPUARMState *env, int size) 378 { 379 abi_ulong sp; 380 381 sp = target_sigsp(get_sp_from_cpustate(env), ka); 382 383 sp = (sp - size) & ~15; 384 385 return sp; 386 } 387 388 typedef struct { 389 int total_size; 390 int extra_base; 391 int extra_size; 392 int std_end_ofs; 393 int extra_ofs; 394 int extra_end_ofs; 395 } target_sigframe_layout; 396 397 static int alloc_sigframe_space(int this_size, target_sigframe_layout *l) 398 { 399 /* Make sure there will always be space for the end marker. */ 400 const int std_size = sizeof(struct target_rt_sigframe) 401 - sizeof(struct target_aarch64_ctx); 402 int this_loc = l->total_size; 403 404 if (l->extra_base) { 405 /* Once we have begun an extra space, all allocations go there. */ 406 l->extra_size += this_size; 407 } else if (this_size + this_loc > std_size) { 408 /* This allocation does not fit in the standard space. */ 409 /* Allocate the extra record. */ 410 l->extra_ofs = this_loc; 411 l->total_size += sizeof(struct target_extra_context); 412 413 /* Allocate the standard end record. */ 414 l->std_end_ofs = l->total_size; 415 l->total_size += sizeof(struct target_aarch64_ctx); 416 417 /* Allocate the requested record. */ 418 l->extra_base = this_loc = l->total_size; 419 l->extra_size = this_size; 420 } 421 l->total_size += this_size; 422 423 return this_loc; 424 } 425 426 static void target_setup_frame(int usig, struct target_sigaction *ka, 427 target_siginfo_t *info, target_sigset_t *set, 428 CPUARMState *env) 429 { 430 target_sigframe_layout layout = { 431 /* Begin with the size pointing to the reserved space. */ 432 .total_size = offsetof(struct target_rt_sigframe, 433 uc.tuc_mcontext.__reserved), 434 }; 435 int fpsimd_ofs, fr_ofs, sve_ofs = 0, vq = 0, sve_size = 0; 436 struct target_rt_sigframe *frame; 437 struct target_rt_frame_record *fr; 438 abi_ulong frame_addr, return_addr; 439 440 /* FPSIMD record is always in the standard space. */ 441 fpsimd_ofs = alloc_sigframe_space(sizeof(struct target_fpsimd_context), 442 &layout); 443 444 /* SVE state needs saving only if it exists. */ 445 if (cpu_isar_feature(aa64_sve, env_archcpu(env))) { 446 vq = sve_vq(env); 447 sve_size = QEMU_ALIGN_UP(TARGET_SVE_SIG_CONTEXT_SIZE(vq), 16); 448 sve_ofs = alloc_sigframe_space(sve_size, &layout); 449 } 450 451 if (layout.extra_ofs) { 452 /* Reserve space for the extra end marker. The standard end marker 453 * will have been allocated when we allocated the extra record. 454 */ 455 layout.extra_end_ofs 456 = alloc_sigframe_space(sizeof(struct target_aarch64_ctx), &layout); 457 } else { 458 /* Reserve space for the standard end marker. 459 * Do not use alloc_sigframe_space because we cheat 460 * std_size therein to reserve space for this. 461 */ 462 layout.std_end_ofs = layout.total_size; 463 layout.total_size += sizeof(struct target_aarch64_ctx); 464 } 465 466 /* We must always provide at least the standard 4K reserved space, 467 * even if we don't use all of it (this is part of the ABI) 468 */ 469 layout.total_size = MAX(layout.total_size, 470 sizeof(struct target_rt_sigframe)); 471 472 /* 473 * Reserve space for the standard frame unwind pair: fp, lr. 474 * Despite the name this is not a "real" record within the frame. 475 */ 476 fr_ofs = layout.total_size; 477 layout.total_size += sizeof(struct target_rt_frame_record); 478 479 frame_addr = get_sigframe(ka, env, layout.total_size); 480 trace_user_setup_frame(env, frame_addr); 481 frame = lock_user(VERIFY_WRITE, frame_addr, layout.total_size, 0); 482 if (!frame) { 483 goto give_sigsegv; 484 } 485 486 target_setup_general_frame(frame, env, set); 487 target_setup_fpsimd_record((void *)frame + fpsimd_ofs, env); 488 target_setup_end_record((void *)frame + layout.std_end_ofs); 489 if (layout.extra_ofs) { 490 target_setup_extra_record((void *)frame + layout.extra_ofs, 491 frame_addr + layout.extra_base, 492 layout.extra_size); 493 target_setup_end_record((void *)frame + layout.extra_end_ofs); 494 } 495 if (sve_ofs) { 496 target_setup_sve_record((void *)frame + sve_ofs, env, vq, sve_size); 497 } 498 499 /* Set up the stack frame for unwinding. */ 500 fr = (void *)frame + fr_ofs; 501 __put_user(env->xregs[29], &fr->fp); 502 __put_user(env->xregs[30], &fr->lr); 503 504 if (ka->sa_flags & TARGET_SA_RESTORER) { 505 return_addr = ka->sa_restorer; 506 } else { 507 return_addr = default_rt_sigreturn; 508 } 509 env->xregs[0] = usig; 510 env->xregs[29] = frame_addr + fr_ofs; 511 env->xregs[30] = return_addr; 512 env->xregs[31] = frame_addr; 513 env->pc = ka->_sa_handler; 514 515 /* Invoke the signal handler as if by indirect call. */ 516 if (cpu_isar_feature(aa64_bti, env_archcpu(env))) { 517 env->btype = 2; 518 } 519 520 if (info) { 521 tswap_siginfo(&frame->info, info); 522 env->xregs[1] = frame_addr + offsetof(struct target_rt_sigframe, info); 523 env->xregs[2] = frame_addr + offsetof(struct target_rt_sigframe, uc); 524 } 525 526 unlock_user(frame, frame_addr, layout.total_size); 527 return; 528 529 give_sigsegv: 530 unlock_user(frame, frame_addr, layout.total_size); 531 force_sigsegv(usig); 532 } 533 534 void setup_rt_frame(int sig, struct target_sigaction *ka, 535 target_siginfo_t *info, target_sigset_t *set, 536 CPUARMState *env) 537 { 538 target_setup_frame(sig, ka, info, set, env); 539 } 540 541 void setup_frame(int sig, struct target_sigaction *ka, 542 target_sigset_t *set, CPUARMState *env) 543 { 544 target_setup_frame(sig, ka, 0, set, env); 545 } 546 547 long do_rt_sigreturn(CPUARMState *env) 548 { 549 struct target_rt_sigframe *frame = NULL; 550 abi_ulong frame_addr = env->xregs[31]; 551 552 trace_user_do_rt_sigreturn(env, frame_addr); 553 if (frame_addr & 15) { 554 goto badframe; 555 } 556 557 if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) { 558 goto badframe; 559 } 560 561 if (target_restore_sigframe(env, frame)) { 562 goto badframe; 563 } 564 565 target_restore_altstack(&frame->uc.tuc_stack, env); 566 567 unlock_user_struct(frame, frame_addr, 0); 568 return -QEMU_ESIGRETURN; 569 570 badframe: 571 unlock_user_struct(frame, frame_addr, 0); 572 force_sig(TARGET_SIGSEGV); 573 return -QEMU_ESIGRETURN; 574 } 575 576 long do_sigreturn(CPUARMState *env) 577 { 578 return do_rt_sigreturn(env); 579 } 580 581 void setup_sigtramp(abi_ulong sigtramp_page) 582 { 583 uint32_t *tramp = lock_user(VERIFY_WRITE, sigtramp_page, 8, 0); 584 assert(tramp != NULL); 585 586 /* 587 * mov x8,#__NR_rt_sigreturn; svc #0 588 * Since these are instructions they need to be put as little-endian 589 * regardless of target default or current CPU endianness. 590 */ 591 __put_user_e(0xd2801168, &tramp[0], le); 592 __put_user_e(0xd4000001, &tramp[1], le); 593 594 default_rt_sigreturn = sigtramp_page; 595 unlock_user(tramp, sigtramp_page, 8); 596 } 597