1 /*- 2 * Copyright (c) 2014 Andrew Turner 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 */ 27 28 #include "opt_ddb.h" 29 30 #include <sys/cdefs.h> 31 __FBSDID("$FreeBSD$"); 32 33 #include <sys/param.h> 34 #include <sys/systm.h> 35 #include <sys/kernel.h> 36 #include <sys/ktr.h> 37 #include <sys/lock.h> 38 #include <sys/mutex.h> 39 #include <sys/proc.h> 40 #include <sys/ptrace.h> 41 #include <sys/syscall.h> 42 #include <sys/sysent.h> 43 #ifdef KDB 44 #include <sys/kdb.h> 45 #endif 46 47 #include <vm/vm.h> 48 #include <vm/pmap.h> 49 #include <vm/vm_kern.h> 50 #include <vm/vm_map.h> 51 #include <vm/vm_param.h> 52 #include <vm/vm_extern.h> 53 54 #include <machine/frame.h> 55 #include <machine/md_var.h> 56 #include <machine/pcb.h> 57 #include <machine/pcpu.h> 58 #include <machine/undefined.h> 59 60 #ifdef KDTRACE_HOOKS 61 #include <sys/dtrace_bsd.h> 62 #endif 63 64 #ifdef VFP 65 #include <machine/vfp.h> 66 #endif 67 68 #ifdef KDB 69 #include <machine/db_machdep.h> 70 #endif 71 72 #ifdef DDB 73 #include <ddb/ddb.h> 74 #include <ddb/db_sym.h> 75 #endif 76 77 /* Called from exception.S */ 78 void do_el1h_sync(struct thread *, struct trapframe *); 79 void do_el0_sync(struct thread *, struct trapframe *); 80 void do_el0_error(struct trapframe *); 81 void do_serror(struct trapframe *); 82 void unhandled_exception(struct trapframe *); 83 84 static void print_gp_register(const char *name, uint64_t value); 85 static void print_registers(struct trapframe *frame); 86 87 int (*dtrace_invop_jump_addr)(struct trapframe *); 88 89 typedef void (abort_handler)(struct thread *, struct trapframe *, uint64_t, 90 uint64_t, int); 91 92 static abort_handler align_abort; 93 static abort_handler data_abort; 94 static abort_handler external_abort; 95 96 static abort_handler *abort_handlers[] = { 97 [ISS_DATA_DFSC_TF_L0] = data_abort, 98 [ISS_DATA_DFSC_TF_L1] = data_abort, 99 [ISS_DATA_DFSC_TF_L2] = data_abort, 100 [ISS_DATA_DFSC_TF_L3] = data_abort, 101 [ISS_DATA_DFSC_AFF_L1] = data_abort, 102 [ISS_DATA_DFSC_AFF_L2] = data_abort, 103 [ISS_DATA_DFSC_AFF_L3] = data_abort, 104 [ISS_DATA_DFSC_PF_L1] = data_abort, 105 [ISS_DATA_DFSC_PF_L2] = data_abort, 106 [ISS_DATA_DFSC_PF_L3] = data_abort, 107 [ISS_DATA_DFSC_ALIGN] = align_abort, 108 [ISS_DATA_DFSC_EXT] = external_abort, 109 [ISS_DATA_DFSC_EXT_L0] = external_abort, 110 [ISS_DATA_DFSC_EXT_L1] = external_abort, 111 [ISS_DATA_DFSC_EXT_L2] = external_abort, 112 [ISS_DATA_DFSC_EXT_L3] = external_abort, 113 [ISS_DATA_DFSC_ECC] = external_abort, 114 [ISS_DATA_DFSC_ECC_L0] = external_abort, 115 [ISS_DATA_DFSC_ECC_L1] = external_abort, 116 [ISS_DATA_DFSC_ECC_L2] = external_abort, 117 [ISS_DATA_DFSC_ECC_L3] = external_abort, 118 }; 119 120 static __inline void 121 call_trapsignal(struct thread *td, int sig, int code, void *addr, int trapno) 122 { 123 ksiginfo_t ksi; 124 125 ksiginfo_init_trap(&ksi); 126 ksi.ksi_signo = sig; 127 ksi.ksi_code = code; 128 ksi.ksi_addr = addr; 129 ksi.ksi_trapno = trapno; 130 trapsignal(td, &ksi); 131 } 132 133 int 134 cpu_fetch_syscall_args(struct thread *td) 135 { 136 struct proc *p; 137 syscallarg_t *ap, *dst_ap; 138 struct syscall_args *sa; 139 140 p = td->td_proc; 141 sa = &td->td_sa; 142 ap = td->td_frame->tf_x; 143 dst_ap = &sa->args[0]; 144 145 sa->code = td->td_frame->tf_x[8]; 146 sa->original_code = sa->code; 147 148 if (__predict_false(sa->code == SYS_syscall || sa->code == SYS___syscall)) { 149 sa->code = *ap++; 150 } else { 151 *dst_ap++ = *ap++; 152 } 153 154 if (__predict_false(sa->code >= p->p_sysent->sv_size)) 155 sa->callp = &p->p_sysent->sv_table[0]; 156 else 157 sa->callp = &p->p_sysent->sv_table[sa->code]; 158 159 KASSERT(sa->callp->sy_narg <= nitems(sa->args), 160 ("Syscall %d takes too many arguments", sa->code)); 161 162 memcpy(dst_ap, ap, (nitems(sa->args) - 1) * sizeof(*dst_ap)); 163 164 td->td_retval[0] = 0; 165 td->td_retval[1] = 0; 166 167 return (0); 168 } 169 170 #include "../../kern/subr_syscall.c" 171 172 /* 173 * Test for fault generated by given access instruction in 174 * bus_peek_<foo> or bus_poke_<foo> bus function. 175 */ 176 extern uint32_t generic_bs_peek_1f, generic_bs_peek_2f; 177 extern uint32_t generic_bs_peek_4f, generic_bs_peek_8f; 178 extern uint32_t generic_bs_poke_1f, generic_bs_poke_2f; 179 extern uint32_t generic_bs_poke_4f, generic_bs_poke_8f; 180 181 static bool 182 test_bs_fault(void *addr) 183 { 184 return (addr == &generic_bs_peek_1f || 185 addr == &generic_bs_peek_2f || 186 addr == &generic_bs_peek_4f || 187 addr == &generic_bs_peek_8f || 188 addr == &generic_bs_poke_1f || 189 addr == &generic_bs_poke_2f || 190 addr == &generic_bs_poke_4f || 191 addr == &generic_bs_poke_8f); 192 } 193 194 static void 195 svc_handler(struct thread *td, struct trapframe *frame) 196 { 197 198 if ((frame->tf_esr & ESR_ELx_ISS_MASK) == 0) { 199 syscallenter(td); 200 syscallret(td); 201 } else { 202 call_trapsignal(td, SIGILL, ILL_ILLOPN, (void *)frame->tf_elr, 203 ESR_ELx_EXCEPTION(frame->tf_esr)); 204 userret(td, frame); 205 } 206 } 207 208 static void 209 align_abort(struct thread *td, struct trapframe *frame, uint64_t esr, 210 uint64_t far, int lower) 211 { 212 if (!lower) { 213 print_registers(frame); 214 print_gp_register("far", far); 215 printf(" esr: %.8lx\n", esr); 216 panic("Misaligned access from kernel space!"); 217 } 218 219 call_trapsignal(td, SIGBUS, BUS_ADRALN, (void *)frame->tf_elr, 220 ESR_ELx_EXCEPTION(frame->tf_esr)); 221 userret(td, frame); 222 } 223 224 225 static void 226 external_abort(struct thread *td, struct trapframe *frame, uint64_t esr, 227 uint64_t far, int lower) 228 { 229 230 /* 231 * Try to handle synchronous external aborts caused by 232 * bus_space_peek() and/or bus_space_poke() functions. 233 */ 234 if (!lower && test_bs_fault((void *)frame->tf_elr)) { 235 frame->tf_elr = (uint64_t)generic_bs_fault; 236 return; 237 } 238 239 print_registers(frame); 240 print_gp_register("far", far); 241 panic("Unhandled EL%d external data abort", lower ? 0: 1); 242 } 243 244 static void 245 data_abort(struct thread *td, struct trapframe *frame, uint64_t esr, 246 uint64_t far, int lower) 247 { 248 struct vm_map *map; 249 struct pcb *pcb; 250 vm_prot_t ftype; 251 int error, sig, ucode; 252 #ifdef KDB 253 bool handled; 254 #endif 255 256 /* 257 * According to the ARMv8-A rev. A.g, B2.10.5 "Load-Exclusive 258 * and Store-Exclusive instruction usage restrictions", state 259 * of the exclusive monitors after data abort exception is unknown. 260 */ 261 clrex(); 262 263 #ifdef KDB 264 if (kdb_active) { 265 kdb_reenter(); 266 return; 267 } 268 #endif 269 270 if (lower) { 271 map = &td->td_proc->p_vmspace->vm_map; 272 } else if (!ADDR_IS_CANONICAL(far)) { 273 /* We received a TBI/PAC/etc. fault from the kernel */ 274 error = KERN_INVALID_ADDRESS; 275 goto bad_far; 276 } else if (ADDR_IS_KERNEL(far)) { 277 /* 278 * Handle a special case: the data abort was caused by accessing 279 * a thread structure while its mapping was being promoted or 280 * demoted, as a consequence of the break-before-make rule. It 281 * is not safe to enable interrupts or dereference "td" before 282 * this case is handled. 283 * 284 * In principle, if pmap_klookup() fails, there is no need to 285 * call pmap_fault() below, but avoiding that call is not worth 286 * the effort. 287 */ 288 if (ESR_ELx_EXCEPTION(esr) == EXCP_DATA_ABORT) { 289 switch (esr & ISS_DATA_DFSC_MASK) { 290 case ISS_DATA_DFSC_TF_L0: 291 case ISS_DATA_DFSC_TF_L1: 292 case ISS_DATA_DFSC_TF_L2: 293 case ISS_DATA_DFSC_TF_L3: 294 if (pmap_klookup(far, NULL)) 295 return; 296 break; 297 } 298 } 299 intr_enable(); 300 map = kernel_map; 301 } else { 302 intr_enable(); 303 map = &td->td_proc->p_vmspace->vm_map; 304 if (map == NULL) 305 map = kernel_map; 306 } 307 pcb = td->td_pcb; 308 309 /* 310 * Try to handle translation, access flag, and permission faults. 311 * Translation faults may occur as a result of the required 312 * break-before-make sequence used when promoting or demoting 313 * superpages. Such faults must not occur while holding the pmap lock, 314 * or pmap_fault() will recurse on that lock. 315 */ 316 if ((lower || map == kernel_map || pcb->pcb_onfault != 0) && 317 pmap_fault(map->pmap, esr, far) == KERN_SUCCESS) 318 return; 319 320 KASSERT(td->td_md.md_spinlock_count == 0, 321 ("data abort with spinlock held")); 322 if (td->td_critnest != 0 || WITNESS_CHECK(WARN_SLEEPOK | 323 WARN_GIANTOK, NULL, "Kernel page fault") != 0) { 324 print_registers(frame); 325 print_gp_register("far", far); 326 printf(" esr: %.8lx\n", esr); 327 panic("data abort in critical section or under mutex"); 328 } 329 330 switch (ESR_ELx_EXCEPTION(esr)) { 331 case EXCP_INSN_ABORT: 332 case EXCP_INSN_ABORT_L: 333 ftype = VM_PROT_EXECUTE; 334 break; 335 default: 336 /* 337 * If the exception was because of a read or cache operation 338 * pass a read fault type into the vm code. Cache operations 339 * need read permission but will set the WnR flag when the 340 * memory is unmapped. 341 */ 342 if ((esr & ISS_DATA_WnR) == 0 || (esr & ISS_DATA_CM) != 0) 343 ftype = VM_PROT_READ; 344 else 345 ftype = VM_PROT_WRITE; 346 break; 347 } 348 349 /* Fault in the page. */ 350 error = vm_fault_trap(map, far, ftype, VM_FAULT_NORMAL, &sig, &ucode); 351 if (error != KERN_SUCCESS) { 352 if (lower) { 353 call_trapsignal(td, sig, ucode, (void *)far, 354 ESR_ELx_EXCEPTION(esr)); 355 } else { 356 bad_far: 357 if (td->td_intr_nesting_level == 0 && 358 pcb->pcb_onfault != 0) { 359 frame->tf_x[0] = error; 360 frame->tf_elr = pcb->pcb_onfault; 361 return; 362 } 363 364 printf("Fatal data abort:\n"); 365 print_registers(frame); 366 print_gp_register("far", far); 367 printf(" esr: %.8lx\n", esr); 368 369 #ifdef KDB 370 if (debugger_on_trap) { 371 kdb_why = KDB_WHY_TRAP; 372 handled = kdb_trap(ESR_ELx_EXCEPTION(esr), 0, 373 frame); 374 kdb_why = KDB_WHY_UNSET; 375 if (handled) 376 return; 377 } 378 #endif 379 panic("vm_fault failed: %lx error %d", 380 frame->tf_elr, error); 381 } 382 } 383 384 if (lower) 385 userret(td, frame); 386 } 387 388 static void 389 print_gp_register(const char *name, uint64_t value) 390 { 391 #if defined(DDB) 392 c_db_sym_t sym; 393 const char *sym_name; 394 db_expr_t sym_value; 395 db_expr_t offset; 396 #endif 397 398 printf(" %s: %16lx", name, value); 399 #if defined(DDB) 400 /* If this looks like a kernel address try to find the symbol */ 401 if (value >= VM_MIN_KERNEL_ADDRESS) { 402 sym = db_search_symbol(value, DB_STGY_ANY, &offset); 403 if (sym != C_DB_SYM_NULL) { 404 db_symbol_values(sym, &sym_name, &sym_value); 405 printf(" (%s + %lx)", sym_name, offset); 406 } 407 } 408 #endif 409 printf("\n"); 410 } 411 412 static void 413 print_registers(struct trapframe *frame) 414 { 415 char name[4]; 416 u_int reg; 417 418 for (reg = 0; reg < nitems(frame->tf_x); reg++) { 419 snprintf(name, sizeof(name), "%sx%d", (reg < 10) ? " " : "", 420 reg); 421 print_gp_register(name, frame->tf_x[reg]); 422 } 423 printf(" sp: %16lx\n", frame->tf_sp); 424 print_gp_register(" lr", frame->tf_lr); 425 print_gp_register("elr", frame->tf_elr); 426 printf("spsr: %8x\n", frame->tf_spsr); 427 } 428 429 #ifdef VFP 430 static void 431 fpe_trap(struct thread *td, void *addr, uint32_t exception) 432 { 433 int code; 434 435 code = FPE_FLTIDO; 436 if ((exception & ISS_FP_TFV) != 0) { 437 if ((exception & ISS_FP_IOF) != 0) 438 code = FPE_FLTINV; 439 else if ((exception & ISS_FP_DZF) != 0) 440 code = FPE_FLTDIV; 441 else if ((exception & ISS_FP_OFF) != 0) 442 code = FPE_FLTOVF; 443 else if ((exception & ISS_FP_UFF) != 0) 444 code = FPE_FLTUND; 445 else if ((exception & ISS_FP_IXF) != 0) 446 code = FPE_FLTRES; 447 } 448 call_trapsignal(td, SIGFPE, code, addr, exception); 449 } 450 #endif 451 452 void 453 do_el1h_sync(struct thread *td, struct trapframe *frame) 454 { 455 uint32_t exception; 456 uint64_t esr, far; 457 int dfsc; 458 459 /* Read the esr register to get the exception details */ 460 esr = frame->tf_esr; 461 exception = ESR_ELx_EXCEPTION(esr); 462 463 #ifdef KDTRACE_HOOKS 464 if (dtrace_trap_func != NULL && (*dtrace_trap_func)(frame, exception)) 465 return; 466 #endif 467 468 CTR4(KTR_TRAP, 469 "do_el1_sync: curthread: %p, esr %lx, elr: %lx, frame: %p", td, 470 esr, frame->tf_elr, frame); 471 472 /* 473 * Enable debug exceptions if we aren't already handling one. They will 474 * be masked again in the exception handler's epilogue. 475 */ 476 if (exception != EXCP_BRK && exception != EXCP_WATCHPT_EL1 && 477 exception != EXCP_SOFTSTP_EL1) 478 dbg_enable(); 479 480 switch (exception) { 481 case EXCP_FP_SIMD: 482 case EXCP_TRAP_FP: 483 #ifdef VFP 484 if ((td->td_pcb->pcb_fpflags & PCB_FP_KERN) != 0) { 485 vfp_restore_state(); 486 } else 487 #endif 488 { 489 print_registers(frame); 490 printf(" esr: %.8lx\n", esr); 491 panic("VFP exception in the kernel"); 492 } 493 break; 494 case EXCP_INSN_ABORT: 495 case EXCP_DATA_ABORT: 496 far = READ_SPECIALREG(far_el1); 497 dfsc = esr & ISS_DATA_DFSC_MASK; 498 if (dfsc < nitems(abort_handlers) && 499 abort_handlers[dfsc] != NULL) { 500 abort_handlers[dfsc](td, frame, esr, far, 0); 501 } else { 502 print_registers(frame); 503 print_gp_register("far", far); 504 printf(" esr: %.8lx\n", esr); 505 panic("Unhandled EL1 %s abort: %x", 506 exception == EXCP_INSN_ABORT ? "instruction" : 507 "data", dfsc); 508 } 509 break; 510 case EXCP_BRK: 511 #ifdef KDTRACE_HOOKS 512 if ((esr & ESR_ELx_ISS_MASK) == 0x40d && \ 513 dtrace_invop_jump_addr != 0) { 514 dtrace_invop_jump_addr(frame); 515 break; 516 } 517 #endif 518 #ifdef KDB 519 kdb_trap(exception, 0, frame); 520 #else 521 panic("No debugger in kernel."); 522 #endif 523 break; 524 case EXCP_WATCHPT_EL1: 525 case EXCP_SOFTSTP_EL1: 526 #ifdef KDB 527 kdb_trap(exception, 0, frame); 528 #else 529 panic("No debugger in kernel."); 530 #endif 531 break; 532 case EXCP_FPAC: 533 /* We can see this if the authentication on PAC fails */ 534 print_registers(frame); 535 printf(" far: %16lx\n", READ_SPECIALREG(far_el1)); 536 panic("FPAC kernel exception"); 537 break; 538 case EXCP_UNKNOWN: 539 if (undef_insn(1, frame)) 540 break; 541 printf("Undefined instruction: %08x\n", 542 *(uint32_t *)frame->tf_elr); 543 /* FALLTHROUGH */ 544 default: 545 print_registers(frame); 546 print_gp_register("far", READ_SPECIALREG(far_el1)); 547 panic("Unknown kernel exception %x esr_el1 %lx", exception, 548 esr); 549 } 550 } 551 552 void 553 do_el0_sync(struct thread *td, struct trapframe *frame) 554 { 555 pcpu_bp_harden bp_harden; 556 uint32_t exception; 557 uint64_t esr, far; 558 int dfsc; 559 560 /* Check we have a sane environment when entering from userland */ 561 KASSERT((uintptr_t)get_pcpu() >= VM_MIN_KERNEL_ADDRESS, 562 ("Invalid pcpu address from userland: %p (tpidr %lx)", 563 get_pcpu(), READ_SPECIALREG(tpidr_el1))); 564 565 esr = frame->tf_esr; 566 exception = ESR_ELx_EXCEPTION(esr); 567 switch (exception) { 568 case EXCP_INSN_ABORT_L: 569 far = READ_SPECIALREG(far_el1); 570 571 /* 572 * Userspace may be trying to train the branch predictor to 573 * attack the kernel. If we are on a CPU affected by this 574 * call the handler to clear the branch predictor state. 575 */ 576 if (far > VM_MAXUSER_ADDRESS) { 577 bp_harden = PCPU_GET(bp_harden); 578 if (bp_harden != NULL) 579 bp_harden(); 580 } 581 break; 582 case EXCP_UNKNOWN: 583 case EXCP_DATA_ABORT_L: 584 case EXCP_DATA_ABORT: 585 case EXCP_WATCHPT_EL0: 586 far = READ_SPECIALREG(far_el1); 587 break; 588 } 589 intr_enable(); 590 591 CTR4(KTR_TRAP, 592 "do_el0_sync: curthread: %p, esr %lx, elr: %lx, frame: %p", td, esr, 593 frame->tf_elr, frame); 594 595 switch (exception) { 596 case EXCP_FP_SIMD: 597 #ifdef VFP 598 vfp_restore_state(); 599 #else 600 panic("VFP exception in userland"); 601 #endif 602 break; 603 case EXCP_TRAP_FP: 604 #ifdef VFP 605 fpe_trap(td, (void *)frame->tf_elr, esr); 606 userret(td, frame); 607 #else 608 panic("VFP exception in userland"); 609 #endif 610 break; 611 case EXCP_SVE: 612 call_trapsignal(td, SIGILL, ILL_ILLTRP, (void *)frame->tf_elr, 613 exception); 614 userret(td, frame); 615 break; 616 case EXCP_SVC32: 617 case EXCP_SVC64: 618 svc_handler(td, frame); 619 break; 620 case EXCP_INSN_ABORT_L: 621 case EXCP_DATA_ABORT_L: 622 case EXCP_DATA_ABORT: 623 dfsc = esr & ISS_DATA_DFSC_MASK; 624 if (dfsc < nitems(abort_handlers) && 625 abort_handlers[dfsc] != NULL) 626 abort_handlers[dfsc](td, frame, esr, far, 1); 627 else { 628 print_registers(frame); 629 print_gp_register("far", far); 630 printf(" esr: %.8lx\n", esr); 631 panic("Unhandled EL0 %s abort: %x", 632 exception == EXCP_INSN_ABORT_L ? "instruction" : 633 "data", dfsc); 634 } 635 break; 636 case EXCP_UNKNOWN: 637 if (!undef_insn(0, frame)) 638 call_trapsignal(td, SIGILL, ILL_ILLTRP, (void *)far, 639 exception); 640 userret(td, frame); 641 break; 642 case EXCP_FPAC: 643 call_trapsignal(td, SIGILL, ILL_ILLOPN, (void *)frame->tf_elr, 644 exception); 645 userret(td, frame); 646 break; 647 case EXCP_SP_ALIGN: 648 call_trapsignal(td, SIGBUS, BUS_ADRALN, (void *)frame->tf_sp, 649 exception); 650 userret(td, frame); 651 break; 652 case EXCP_PC_ALIGN: 653 call_trapsignal(td, SIGBUS, BUS_ADRALN, (void *)frame->tf_elr, 654 exception); 655 userret(td, frame); 656 break; 657 case EXCP_BRKPT_EL0: 658 case EXCP_BRK: 659 #ifdef COMPAT_FREEBSD32 660 case EXCP_BRKPT_32: 661 #endif /* COMPAT_FREEBSD32 */ 662 call_trapsignal(td, SIGTRAP, TRAP_BRKPT, (void *)frame->tf_elr, 663 exception); 664 userret(td, frame); 665 break; 666 case EXCP_WATCHPT_EL0: 667 call_trapsignal(td, SIGTRAP, TRAP_TRACE, (void *)far, 668 exception); 669 userret(td, frame); 670 break; 671 case EXCP_MSR: 672 /* 673 * The CPU can raise EXCP_MSR when userspace executes an mrs 674 * instruction to access a special register userspace doesn't 675 * have access to. 676 */ 677 if (!undef_insn(0, frame)) 678 call_trapsignal(td, SIGILL, ILL_PRVOPC, 679 (void *)frame->tf_elr, exception); 680 userret(td, frame); 681 break; 682 case EXCP_SOFTSTP_EL0: 683 PROC_LOCK(td->td_proc); 684 if ((td->td_dbgflags & TDB_STEP) != 0) { 685 td->td_frame->tf_spsr &= ~PSR_SS; 686 td->td_pcb->pcb_flags &= ~PCB_SINGLE_STEP; 687 WRITE_SPECIALREG(mdscr_el1, 688 READ_SPECIALREG(mdscr_el1) & ~MDSCR_SS); 689 } 690 PROC_UNLOCK(td->td_proc); 691 call_trapsignal(td, SIGTRAP, TRAP_TRACE, 692 (void *)frame->tf_elr, exception); 693 userret(td, frame); 694 break; 695 default: 696 call_trapsignal(td, SIGBUS, BUS_OBJERR, (void *)frame->tf_elr, 697 exception); 698 userret(td, frame); 699 break; 700 } 701 702 KASSERT((td->td_pcb->pcb_fpflags & ~PCB_FP_USERMASK) == 0, 703 ("Kernel VFP flags set while entering userspace")); 704 KASSERT( 705 td->td_pcb->pcb_fpusaved == &td->td_pcb->pcb_fpustate, 706 ("Kernel VFP state in use when entering userspace")); 707 } 708 709 /* 710 * TODO: We will need to handle these later when we support ARMv8.2 RAS. 711 */ 712 void 713 do_serror(struct trapframe *frame) 714 { 715 uint64_t esr, far; 716 717 far = READ_SPECIALREG(far_el1); 718 esr = frame->tf_esr; 719 720 print_registers(frame); 721 print_gp_register("far", far); 722 printf(" esr: %.8lx\n", esr); 723 panic("Unhandled System Error"); 724 } 725 726 void 727 unhandled_exception(struct trapframe *frame) 728 { 729 uint64_t esr, far; 730 731 far = READ_SPECIALREG(far_el1); 732 esr = frame->tf_esr; 733 734 print_registers(frame); 735 print_gp_register("far", far); 736 printf(" esr: %.8lx\n", esr); 737 panic("Unhandled exception"); 738 } 739