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 "target_signal.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 reserved[3]; 82 /* The actual SVE data immediately follows. It is layed out 83 * according to TARGET_SVE_SIG_{Z,P}REG_OFFSET, based off of 84 * the original struct pointer. 85 */ 86 }; 87 88 #define TARGET_SVE_VQ_BYTES 16 89 90 #define TARGET_SVE_SIG_ZREG_SIZE(VQ) ((VQ) * TARGET_SVE_VQ_BYTES) 91 #define TARGET_SVE_SIG_PREG_SIZE(VQ) ((VQ) * (TARGET_SVE_VQ_BYTES / 8)) 92 93 #define TARGET_SVE_SIG_REGS_OFFSET \ 94 QEMU_ALIGN_UP(sizeof(struct target_sve_context), TARGET_SVE_VQ_BYTES) 95 #define TARGET_SVE_SIG_ZREG_OFFSET(VQ, N) \ 96 (TARGET_SVE_SIG_REGS_OFFSET + TARGET_SVE_SIG_ZREG_SIZE(VQ) * (N)) 97 #define TARGET_SVE_SIG_PREG_OFFSET(VQ, N) \ 98 (TARGET_SVE_SIG_ZREG_OFFSET(VQ, 32) + TARGET_SVE_SIG_PREG_SIZE(VQ) * (N)) 99 #define TARGET_SVE_SIG_FFR_OFFSET(VQ) \ 100 (TARGET_SVE_SIG_PREG_OFFSET(VQ, 16)) 101 #define TARGET_SVE_SIG_CONTEXT_SIZE(VQ) \ 102 (TARGET_SVE_SIG_PREG_OFFSET(VQ, 17)) 103 104 struct target_rt_sigframe { 105 struct target_siginfo info; 106 struct target_ucontext uc; 107 }; 108 109 struct target_rt_frame_record { 110 uint64_t fp; 111 uint64_t lr; 112 uint32_t tramp[2]; 113 }; 114 115 static void target_setup_general_frame(struct target_rt_sigframe *sf, 116 CPUARMState *env, target_sigset_t *set) 117 { 118 int i; 119 120 __put_user(0, &sf->uc.tuc_flags); 121 __put_user(0, &sf->uc.tuc_link); 122 123 __put_user(target_sigaltstack_used.ss_sp, &sf->uc.tuc_stack.ss_sp); 124 __put_user(sas_ss_flags(env->xregs[31]), &sf->uc.tuc_stack.ss_flags); 125 __put_user(target_sigaltstack_used.ss_size, &sf->uc.tuc_stack.ss_size); 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 #ifdef TARGET_WORDS_BIGENDIAN 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 __put_user(TARGET_SVE_MAGIC, &sve->head.magic); 184 __put_user(size, &sve->head.size); 185 __put_user(vq * TARGET_SVE_VQ_BYTES, &sve->vl); 186 187 /* Note that SVE regs are stored as a byte stream, with each byte element 188 * at a subsequent address. This corresponds to a little-endian store 189 * of our 64-bit hunks. 190 */ 191 for (i = 0; i < 32; ++i) { 192 uint64_t *z = (void *)sve + TARGET_SVE_SIG_ZREG_OFFSET(vq, i); 193 for (j = 0; j < vq * 2; ++j) { 194 __put_user_e(env->vfp.zregs[i].d[j], z + j, le); 195 } 196 } 197 for (i = 0; i <= 16; ++i) { 198 uint16_t *p = (void *)sve + TARGET_SVE_SIG_PREG_OFFSET(vq, i); 199 for (j = 0; j < vq; ++j) { 200 uint64_t r = env->vfp.pregs[i].p[j >> 2]; 201 __put_user_e(r >> ((j & 3) * 16), p + j, le); 202 } 203 } 204 } 205 206 static void target_restore_general_frame(CPUARMState *env, 207 struct target_rt_sigframe *sf) 208 { 209 sigset_t set; 210 uint64_t pstate; 211 int i; 212 213 target_to_host_sigset(&set, &sf->uc.tuc_sigmask); 214 set_sigmask(&set); 215 216 for (i = 0; i < 31; i++) { 217 __get_user(env->xregs[i], &sf->uc.tuc_mcontext.regs[i]); 218 } 219 220 __get_user(env->xregs[31], &sf->uc.tuc_mcontext.sp); 221 __get_user(env->pc, &sf->uc.tuc_mcontext.pc); 222 __get_user(pstate, &sf->uc.tuc_mcontext.pstate); 223 pstate_write(env, pstate); 224 } 225 226 static void target_restore_fpsimd_record(CPUARMState *env, 227 struct target_fpsimd_context *fpsimd) 228 { 229 uint32_t fpsr, fpcr; 230 int i; 231 232 __get_user(fpsr, &fpsimd->fpsr); 233 vfp_set_fpsr(env, fpsr); 234 __get_user(fpcr, &fpsimd->fpcr); 235 vfp_set_fpcr(env, fpcr); 236 237 for (i = 0; i < 32; i++) { 238 uint64_t *q = aa64_vfp_qreg(env, i); 239 #ifdef TARGET_WORDS_BIGENDIAN 240 __get_user(q[0], &fpsimd->vregs[i * 2 + 1]); 241 __get_user(q[1], &fpsimd->vregs[i * 2]); 242 #else 243 __get_user(q[0], &fpsimd->vregs[i * 2]); 244 __get_user(q[1], &fpsimd->vregs[i * 2 + 1]); 245 #endif 246 } 247 } 248 249 static void target_restore_sve_record(CPUARMState *env, 250 struct target_sve_context *sve, int vq) 251 { 252 int i, j; 253 254 /* Note that SVE regs are stored as a byte stream, with each byte element 255 * at a subsequent address. This corresponds to a little-endian load 256 * of our 64-bit hunks. 257 */ 258 for (i = 0; i < 32; ++i) { 259 uint64_t *z = (void *)sve + TARGET_SVE_SIG_ZREG_OFFSET(vq, i); 260 for (j = 0; j < vq * 2; ++j) { 261 __get_user_e(env->vfp.zregs[i].d[j], z + j, le); 262 } 263 } 264 for (i = 0; i <= 16; ++i) { 265 uint16_t *p = (void *)sve + TARGET_SVE_SIG_PREG_OFFSET(vq, i); 266 for (j = 0; j < vq; ++j) { 267 uint16_t r; 268 __get_user_e(r, p + j, le); 269 if (j & 3) { 270 env->vfp.pregs[i].p[j >> 2] |= (uint64_t)r << ((j & 3) * 16); 271 } else { 272 env->vfp.pregs[i].p[j >> 2] = r; 273 } 274 } 275 } 276 } 277 278 static int target_restore_sigframe(CPUARMState *env, 279 struct target_rt_sigframe *sf) 280 { 281 struct target_aarch64_ctx *ctx, *extra = NULL; 282 struct target_fpsimd_context *fpsimd = NULL; 283 struct target_sve_context *sve = NULL; 284 uint64_t extra_datap = 0; 285 bool used_extra = false; 286 bool err = false; 287 int vq = 0, sve_size = 0; 288 289 target_restore_general_frame(env, sf); 290 291 ctx = (struct target_aarch64_ctx *)sf->uc.tuc_mcontext.__reserved; 292 while (ctx) { 293 uint32_t magic, size, extra_size; 294 295 __get_user(magic, &ctx->magic); 296 __get_user(size, &ctx->size); 297 switch (magic) { 298 case 0: 299 if (size != 0) { 300 err = true; 301 goto exit; 302 } 303 if (used_extra) { 304 ctx = NULL; 305 } else { 306 ctx = extra; 307 used_extra = true; 308 } 309 continue; 310 311 case TARGET_FPSIMD_MAGIC: 312 if (fpsimd || size != sizeof(struct target_fpsimd_context)) { 313 err = true; 314 goto exit; 315 } 316 fpsimd = (struct target_fpsimd_context *)ctx; 317 break; 318 319 case TARGET_SVE_MAGIC: 320 if (arm_feature(env, ARM_FEATURE_SVE)) { 321 vq = (env->vfp.zcr_el[1] & 0xf) + 1; 322 sve_size = QEMU_ALIGN_UP(TARGET_SVE_SIG_CONTEXT_SIZE(vq), 16); 323 if (!sve && size == sve_size) { 324 sve = (struct target_sve_context *)ctx; 325 break; 326 } 327 } 328 err = true; 329 goto exit; 330 331 case TARGET_EXTRA_MAGIC: 332 if (extra || size != sizeof(struct target_extra_context)) { 333 err = true; 334 goto exit; 335 } 336 __get_user(extra_datap, 337 &((struct target_extra_context *)ctx)->datap); 338 __get_user(extra_size, 339 &((struct target_extra_context *)ctx)->size); 340 extra = lock_user(VERIFY_READ, extra_datap, extra_size, 0); 341 break; 342 343 default: 344 /* Unknown record -- we certainly didn't generate it. 345 * Did we in fact get out of sync? 346 */ 347 err = true; 348 goto exit; 349 } 350 ctx = (void *)ctx + size; 351 } 352 353 /* Require FPSIMD always. */ 354 if (fpsimd) { 355 target_restore_fpsimd_record(env, fpsimd); 356 } else { 357 err = true; 358 } 359 360 /* SVE data, if present, overwrites FPSIMD data. */ 361 if (sve) { 362 target_restore_sve_record(env, sve, vq); 363 } 364 365 exit: 366 unlock_user(extra, extra_datap, 0); 367 return err; 368 } 369 370 static abi_ulong get_sigframe(struct target_sigaction *ka, 371 CPUARMState *env, int size) 372 { 373 abi_ulong sp; 374 375 sp = env->xregs[31]; 376 377 /* 378 * This is the X/Open sanctioned signal stack switching. 379 */ 380 if ((ka->sa_flags & TARGET_SA_ONSTACK) && !sas_ss_flags(sp)) { 381 sp = target_sigaltstack_used.ss_sp + target_sigaltstack_used.ss_size; 382 } 383 384 sp = (sp - size) & ~15; 385 386 return sp; 387 } 388 389 typedef struct { 390 int total_size; 391 int extra_base; 392 int extra_size; 393 int std_end_ofs; 394 int extra_ofs; 395 int extra_end_ofs; 396 } target_sigframe_layout; 397 398 static int alloc_sigframe_space(int this_size, target_sigframe_layout *l) 399 { 400 /* Make sure there will always be space for the end marker. */ 401 const int std_size = sizeof(struct target_rt_sigframe) 402 - sizeof(struct target_aarch64_ctx); 403 int this_loc = l->total_size; 404 405 if (l->extra_base) { 406 /* Once we have begun an extra space, all allocations go there. */ 407 l->extra_size += this_size; 408 } else if (this_size + this_loc > std_size) { 409 /* This allocation does not fit in the standard space. */ 410 /* Allocate the extra record. */ 411 l->extra_ofs = this_loc; 412 l->total_size += sizeof(struct target_extra_context); 413 414 /* Allocate the standard end record. */ 415 l->std_end_ofs = l->total_size; 416 l->total_size += sizeof(struct target_aarch64_ctx); 417 418 /* Allocate the requested record. */ 419 l->extra_base = this_loc = l->total_size; 420 l->extra_size = this_size; 421 } 422 l->total_size += this_size; 423 424 return this_loc; 425 } 426 427 static void target_setup_frame(int usig, struct target_sigaction *ka, 428 target_siginfo_t *info, target_sigset_t *set, 429 CPUARMState *env) 430 { 431 target_sigframe_layout layout = { 432 /* Begin with the size pointing to the reserved space. */ 433 .total_size = offsetof(struct target_rt_sigframe, 434 uc.tuc_mcontext.__reserved), 435 }; 436 int fpsimd_ofs, fr_ofs, sve_ofs = 0, vq = 0, sve_size = 0; 437 struct target_rt_sigframe *frame; 438 struct target_rt_frame_record *fr; 439 abi_ulong frame_addr, return_addr; 440 441 /* FPSIMD record is always in the standard space. */ 442 fpsimd_ofs = alloc_sigframe_space(sizeof(struct target_fpsimd_context), 443 &layout); 444 445 /* SVE state needs saving only if it exists. */ 446 if (arm_feature(env, ARM_FEATURE_SVE)) { 447 vq = (env->vfp.zcr_el[1] & 0xf) + 1; 448 sve_size = QEMU_ALIGN_UP(TARGET_SVE_SIG_CONTEXT_SIZE(vq), 16); 449 sve_ofs = alloc_sigframe_space(sve_size, &layout); 450 } 451 452 if (layout.extra_ofs) { 453 /* Reserve space for the extra end marker. The standard end marker 454 * will have been allocated when we allocated the extra record. 455 */ 456 layout.extra_end_ofs 457 = alloc_sigframe_space(sizeof(struct target_aarch64_ctx), &layout); 458 } else { 459 /* Reserve space for the standard end marker. 460 * Do not use alloc_sigframe_space because we cheat 461 * std_size therein to reserve space for this. 462 */ 463 layout.std_end_ofs = layout.total_size; 464 layout.total_size += sizeof(struct target_aarch64_ctx); 465 } 466 467 /* We must always provide at least the standard 4K reserved space, 468 * even if we don't use all of it (this is part of the ABI) 469 */ 470 layout.total_size = MAX(layout.total_size, 471 sizeof(struct target_rt_sigframe)); 472 473 /* Reserve space for the return code. On a real system this would 474 * be within the VDSO. So, despite the name this is not a "real" 475 * record within the frame. 476 */ 477 fr_ofs = layout.total_size; 478 layout.total_size += sizeof(struct target_rt_frame_record); 479 480 frame_addr = get_sigframe(ka, env, layout.total_size); 481 trace_user_setup_frame(env, frame_addr); 482 frame = lock_user(VERIFY_WRITE, frame_addr, layout.total_size, 0); 483 if (!frame) { 484 goto give_sigsegv; 485 } 486 487 target_setup_general_frame(frame, env, set); 488 target_setup_fpsimd_record((void *)frame + fpsimd_ofs, env); 489 target_setup_end_record((void *)frame + layout.std_end_ofs); 490 if (layout.extra_ofs) { 491 target_setup_extra_record((void *)frame + layout.extra_ofs, 492 frame_addr + layout.extra_base, 493 layout.extra_size); 494 target_setup_end_record((void *)frame + layout.extra_end_ofs); 495 } 496 if (sve_ofs) { 497 target_setup_sve_record((void *)frame + sve_ofs, env, vq, sve_size); 498 } 499 500 /* Set up the stack frame for unwinding. */ 501 fr = (void *)frame + fr_ofs; 502 __put_user(env->xregs[29], &fr->fp); 503 __put_user(env->xregs[30], &fr->lr); 504 505 if (ka->sa_flags & TARGET_SA_RESTORER) { 506 return_addr = ka->sa_restorer; 507 } else { 508 /* 509 * mov x8,#__NR_rt_sigreturn; svc #0 510 * Since these are instructions they need to be put as little-endian 511 * regardless of target default or current CPU endianness. 512 */ 513 __put_user_e(0xd2801168, &fr->tramp[0], le); 514 __put_user_e(0xd4000001, &fr->tramp[1], le); 515 return_addr = frame_addr + fr_ofs 516 + offsetof(struct target_rt_frame_record, tramp); 517 } 518 env->xregs[0] = usig; 519 env->xregs[31] = frame_addr; 520 env->xregs[29] = frame_addr + fr_ofs; 521 env->pc = ka->_sa_handler; 522 env->xregs[30] = return_addr; 523 if (info) { 524 tswap_siginfo(&frame->info, info); 525 env->xregs[1] = frame_addr + offsetof(struct target_rt_sigframe, info); 526 env->xregs[2] = frame_addr + offsetof(struct target_rt_sigframe, uc); 527 } 528 529 unlock_user(frame, frame_addr, layout.total_size); 530 return; 531 532 give_sigsegv: 533 unlock_user(frame, frame_addr, layout.total_size); 534 force_sigsegv(usig); 535 } 536 537 void setup_rt_frame(int sig, struct target_sigaction *ka, 538 target_siginfo_t *info, target_sigset_t *set, 539 CPUARMState *env) 540 { 541 target_setup_frame(sig, ka, info, set, env); 542 } 543 544 void setup_frame(int sig, struct target_sigaction *ka, 545 target_sigset_t *set, CPUARMState *env) 546 { 547 target_setup_frame(sig, ka, 0, set, env); 548 } 549 550 long do_rt_sigreturn(CPUARMState *env) 551 { 552 struct target_rt_sigframe *frame = NULL; 553 abi_ulong frame_addr = env->xregs[31]; 554 555 trace_user_do_rt_sigreturn(env, frame_addr); 556 if (frame_addr & 15) { 557 goto badframe; 558 } 559 560 if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) { 561 goto badframe; 562 } 563 564 if (target_restore_sigframe(env, frame)) { 565 goto badframe; 566 } 567 568 if (do_sigaltstack(frame_addr + 569 offsetof(struct target_rt_sigframe, uc.tuc_stack), 570 0, get_sp_from_cpustate(env)) == -EFAULT) { 571 goto badframe; 572 } 573 574 unlock_user_struct(frame, frame_addr, 0); 575 return -TARGET_QEMU_ESIGRETURN; 576 577 badframe: 578 unlock_user_struct(frame, frame_addr, 0); 579 force_sig(TARGET_SIGSEGV); 580 return -TARGET_QEMU_ESIGRETURN; 581 } 582 583 long do_sigreturn(CPUARMState *env) 584 { 585 return do_rt_sigreturn(env); 586 } 587