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 /* 245 * It is unsafe to access the stack canary value stored in "td" until 246 * kernel map translation faults are handled, see the pmap_klookup() call below. 247 * Thus, stack-smashing detection with per-thread canaries must be disabled in 248 * this function. 249 */ 250 static void NO_PERTHREAD_SSP 251 data_abort(struct thread *td, struct trapframe *frame, uint64_t esr, 252 uint64_t far, int lower) 253 { 254 struct vm_map *map; 255 struct pcb *pcb; 256 vm_prot_t ftype; 257 int error, sig, ucode; 258 #ifdef KDB 259 bool handled; 260 #endif 261 262 /* 263 * According to the ARMv8-A rev. A.g, B2.10.5 "Load-Exclusive 264 * and Store-Exclusive instruction usage restrictions", state 265 * of the exclusive monitors after data abort exception is unknown. 266 */ 267 clrex(); 268 269 #ifdef KDB 270 if (kdb_active) { 271 kdb_reenter(); 272 return; 273 } 274 #endif 275 276 if (lower) { 277 map = &td->td_proc->p_vmspace->vm_map; 278 } else if (!ADDR_IS_CANONICAL(far)) { 279 /* We received a TBI/PAC/etc. fault from the kernel */ 280 error = KERN_INVALID_ADDRESS; 281 goto bad_far; 282 } else if (ADDR_IS_KERNEL(far)) { 283 /* 284 * Handle a special case: the data abort was caused by accessing 285 * a thread structure while its mapping was being promoted or 286 * demoted, as a consequence of the break-before-make rule. It 287 * is not safe to enable interrupts or dereference "td" before 288 * this case is handled. 289 * 290 * In principle, if pmap_klookup() fails, there is no need to 291 * call pmap_fault() below, but avoiding that call is not worth 292 * the effort. 293 */ 294 if (ESR_ELx_EXCEPTION(esr) == EXCP_DATA_ABORT) { 295 switch (esr & ISS_DATA_DFSC_MASK) { 296 case ISS_DATA_DFSC_TF_L0: 297 case ISS_DATA_DFSC_TF_L1: 298 case ISS_DATA_DFSC_TF_L2: 299 case ISS_DATA_DFSC_TF_L3: 300 if (pmap_klookup(far, NULL)) 301 return; 302 break; 303 } 304 } 305 intr_enable(); 306 map = kernel_map; 307 } else { 308 intr_enable(); 309 map = &td->td_proc->p_vmspace->vm_map; 310 if (map == NULL) 311 map = kernel_map; 312 } 313 pcb = td->td_pcb; 314 315 /* 316 * Try to handle translation, access flag, and permission faults. 317 * Translation faults may occur as a result of the required 318 * break-before-make sequence used when promoting or demoting 319 * superpages. Such faults must not occur while holding the pmap lock, 320 * or pmap_fault() will recurse on that lock. 321 */ 322 if ((lower || map == kernel_map || pcb->pcb_onfault != 0) && 323 pmap_fault(map->pmap, esr, far) == KERN_SUCCESS) 324 return; 325 326 KASSERT(td->td_md.md_spinlock_count == 0, 327 ("data abort with spinlock held")); 328 if (td->td_critnest != 0 || WITNESS_CHECK(WARN_SLEEPOK | 329 WARN_GIANTOK, NULL, "Kernel page fault") != 0) { 330 print_registers(frame); 331 print_gp_register("far", far); 332 printf(" esr: %.8lx\n", esr); 333 panic("data abort in critical section or under mutex"); 334 } 335 336 switch (ESR_ELx_EXCEPTION(esr)) { 337 case EXCP_INSN_ABORT: 338 case EXCP_INSN_ABORT_L: 339 ftype = VM_PROT_EXECUTE; 340 break; 341 default: 342 /* 343 * If the exception was because of a read or cache operation 344 * pass a read fault type into the vm code. Cache operations 345 * need read permission but will set the WnR flag when the 346 * memory is unmapped. 347 */ 348 if ((esr & ISS_DATA_WnR) == 0 || (esr & ISS_DATA_CM) != 0) 349 ftype = VM_PROT_READ; 350 else 351 ftype = VM_PROT_WRITE; 352 break; 353 } 354 355 /* Fault in the page. */ 356 error = vm_fault_trap(map, far, ftype, VM_FAULT_NORMAL, &sig, &ucode); 357 if (error != KERN_SUCCESS) { 358 if (lower) { 359 call_trapsignal(td, sig, ucode, (void *)far, 360 ESR_ELx_EXCEPTION(esr)); 361 } else { 362 bad_far: 363 if (td->td_intr_nesting_level == 0 && 364 pcb->pcb_onfault != 0) { 365 frame->tf_x[0] = error; 366 frame->tf_elr = pcb->pcb_onfault; 367 return; 368 } 369 370 printf("Fatal data abort:\n"); 371 print_registers(frame); 372 print_gp_register("far", far); 373 printf(" esr: %.8lx\n", esr); 374 375 #ifdef KDB 376 if (debugger_on_trap) { 377 kdb_why = KDB_WHY_TRAP; 378 handled = kdb_trap(ESR_ELx_EXCEPTION(esr), 0, 379 frame); 380 kdb_why = KDB_WHY_UNSET; 381 if (handled) 382 return; 383 } 384 #endif 385 panic("vm_fault failed: %lx error %d", 386 frame->tf_elr, error); 387 } 388 } 389 390 if (lower) 391 userret(td, frame); 392 } 393 394 static void 395 print_gp_register(const char *name, uint64_t value) 396 { 397 #if defined(DDB) 398 c_db_sym_t sym; 399 const char *sym_name; 400 db_expr_t sym_value; 401 db_expr_t offset; 402 #endif 403 404 printf(" %s: %16lx", name, value); 405 #if defined(DDB) 406 /* If this looks like a kernel address try to find the symbol */ 407 if (value >= VM_MIN_KERNEL_ADDRESS) { 408 sym = db_search_symbol(value, DB_STGY_ANY, &offset); 409 if (sym != C_DB_SYM_NULL) { 410 db_symbol_values(sym, &sym_name, &sym_value); 411 printf(" (%s + %lx)", sym_name, offset); 412 } 413 } 414 #endif 415 printf("\n"); 416 } 417 418 static void 419 print_registers(struct trapframe *frame) 420 { 421 char name[4]; 422 u_int reg; 423 424 for (reg = 0; reg < nitems(frame->tf_x); reg++) { 425 snprintf(name, sizeof(name), "%sx%d", (reg < 10) ? " " : "", 426 reg); 427 print_gp_register(name, frame->tf_x[reg]); 428 } 429 printf(" sp: %16lx\n", frame->tf_sp); 430 print_gp_register(" lr", frame->tf_lr); 431 print_gp_register("elr", frame->tf_elr); 432 printf("spsr: %8x\n", frame->tf_spsr); 433 } 434 435 #ifdef VFP 436 static void 437 fpe_trap(struct thread *td, void *addr, uint32_t exception) 438 { 439 int code; 440 441 code = FPE_FLTIDO; 442 if ((exception & ISS_FP_TFV) != 0) { 443 if ((exception & ISS_FP_IOF) != 0) 444 code = FPE_FLTINV; 445 else if ((exception & ISS_FP_DZF) != 0) 446 code = FPE_FLTDIV; 447 else if ((exception & ISS_FP_OFF) != 0) 448 code = FPE_FLTOVF; 449 else if ((exception & ISS_FP_UFF) != 0) 450 code = FPE_FLTUND; 451 else if ((exception & ISS_FP_IXF) != 0) 452 code = FPE_FLTRES; 453 } 454 call_trapsignal(td, SIGFPE, code, addr, exception); 455 } 456 #endif 457 458 /* 459 * See the comment above data_abort(). 460 */ 461 void NO_PERTHREAD_SSP 462 do_el1h_sync(struct thread *td, struct trapframe *frame) 463 { 464 uint32_t exception; 465 uint64_t esr, far; 466 int dfsc; 467 468 /* Read the esr register to get the exception details */ 469 esr = frame->tf_esr; 470 exception = ESR_ELx_EXCEPTION(esr); 471 472 #ifdef KDTRACE_HOOKS 473 if (dtrace_trap_func != NULL && (*dtrace_trap_func)(frame, exception)) 474 return; 475 #endif 476 477 CTR4(KTR_TRAP, 478 "do_el1_sync: curthread: %p, esr %lx, elr: %lx, frame: %p", td, 479 esr, frame->tf_elr, frame); 480 481 /* 482 * Enable debug exceptions if we aren't already handling one. They will 483 * be masked again in the exception handler's epilogue. 484 */ 485 if (exception != EXCP_BRK && exception != EXCP_WATCHPT_EL1 && 486 exception != EXCP_SOFTSTP_EL1) 487 dbg_enable(); 488 489 switch (exception) { 490 case EXCP_FP_SIMD: 491 case EXCP_TRAP_FP: 492 #ifdef VFP 493 if ((td->td_pcb->pcb_fpflags & PCB_FP_KERN) != 0) { 494 vfp_restore_state(); 495 } else 496 #endif 497 { 498 print_registers(frame); 499 printf(" esr: %.8lx\n", esr); 500 panic("VFP exception in the kernel"); 501 } 502 break; 503 case EXCP_INSN_ABORT: 504 case EXCP_DATA_ABORT: 505 far = READ_SPECIALREG(far_el1); 506 dfsc = esr & ISS_DATA_DFSC_MASK; 507 if (dfsc < nitems(abort_handlers) && 508 abort_handlers[dfsc] != NULL) { 509 abort_handlers[dfsc](td, frame, esr, far, 0); 510 } else { 511 print_registers(frame); 512 print_gp_register("far", far); 513 printf(" esr: %.8lx\n", esr); 514 panic("Unhandled EL1 %s abort: %x", 515 exception == EXCP_INSN_ABORT ? "instruction" : 516 "data", dfsc); 517 } 518 break; 519 case EXCP_BRK: 520 #ifdef KDTRACE_HOOKS 521 if ((esr & ESR_ELx_ISS_MASK) == 0x40d && \ 522 dtrace_invop_jump_addr != 0) { 523 dtrace_invop_jump_addr(frame); 524 break; 525 } 526 #endif 527 #ifdef KDB 528 kdb_trap(exception, 0, frame); 529 #else 530 panic("No debugger in kernel."); 531 #endif 532 break; 533 case EXCP_WATCHPT_EL1: 534 case EXCP_SOFTSTP_EL1: 535 #ifdef KDB 536 kdb_trap(exception, 0, frame); 537 #else 538 panic("No debugger in kernel."); 539 #endif 540 break; 541 case EXCP_FPAC: 542 /* We can see this if the authentication on PAC fails */ 543 print_registers(frame); 544 printf(" far: %16lx\n", READ_SPECIALREG(far_el1)); 545 panic("FPAC kernel exception"); 546 break; 547 case EXCP_UNKNOWN: 548 if (undef_insn(1, frame)) 549 break; 550 printf("Undefined instruction: %08x\n", 551 *(uint32_t *)frame->tf_elr); 552 /* FALLTHROUGH */ 553 default: 554 print_registers(frame); 555 print_gp_register("far", READ_SPECIALREG(far_el1)); 556 panic("Unknown kernel exception %x esr_el1 %lx", exception, 557 esr); 558 } 559 } 560 561 void 562 do_el0_sync(struct thread *td, struct trapframe *frame) 563 { 564 pcpu_bp_harden bp_harden; 565 uint32_t exception; 566 uint64_t esr, far; 567 int dfsc; 568 569 /* Check we have a sane environment when entering from userland */ 570 KASSERT((uintptr_t)get_pcpu() >= VM_MIN_KERNEL_ADDRESS, 571 ("Invalid pcpu address from userland: %p (tpidr %lx)", 572 get_pcpu(), READ_SPECIALREG(tpidr_el1))); 573 574 esr = frame->tf_esr; 575 exception = ESR_ELx_EXCEPTION(esr); 576 switch (exception) { 577 case EXCP_INSN_ABORT_L: 578 far = READ_SPECIALREG(far_el1); 579 580 /* 581 * Userspace may be trying to train the branch predictor to 582 * attack the kernel. If we are on a CPU affected by this 583 * call the handler to clear the branch predictor state. 584 */ 585 if (far > VM_MAXUSER_ADDRESS) { 586 bp_harden = PCPU_GET(bp_harden); 587 if (bp_harden != NULL) 588 bp_harden(); 589 } 590 break; 591 case EXCP_UNKNOWN: 592 case EXCP_DATA_ABORT_L: 593 case EXCP_DATA_ABORT: 594 case EXCP_WATCHPT_EL0: 595 far = READ_SPECIALREG(far_el1); 596 break; 597 } 598 intr_enable(); 599 600 CTR4(KTR_TRAP, 601 "do_el0_sync: curthread: %p, esr %lx, elr: %lx, frame: %p", td, esr, 602 frame->tf_elr, frame); 603 604 switch (exception) { 605 case EXCP_FP_SIMD: 606 #ifdef VFP 607 vfp_restore_state(); 608 #else 609 panic("VFP exception in userland"); 610 #endif 611 break; 612 case EXCP_TRAP_FP: 613 #ifdef VFP 614 fpe_trap(td, (void *)frame->tf_elr, esr); 615 userret(td, frame); 616 #else 617 panic("VFP exception in userland"); 618 #endif 619 break; 620 case EXCP_SVE: 621 call_trapsignal(td, SIGILL, ILL_ILLTRP, (void *)frame->tf_elr, 622 exception); 623 userret(td, frame); 624 break; 625 case EXCP_SVC32: 626 case EXCP_SVC64: 627 svc_handler(td, frame); 628 break; 629 case EXCP_INSN_ABORT_L: 630 case EXCP_DATA_ABORT_L: 631 case EXCP_DATA_ABORT: 632 dfsc = esr & ISS_DATA_DFSC_MASK; 633 if (dfsc < nitems(abort_handlers) && 634 abort_handlers[dfsc] != NULL) 635 abort_handlers[dfsc](td, frame, esr, far, 1); 636 else { 637 print_registers(frame); 638 print_gp_register("far", far); 639 printf(" esr: %.8lx\n", esr); 640 panic("Unhandled EL0 %s abort: %x", 641 exception == EXCP_INSN_ABORT_L ? "instruction" : 642 "data", dfsc); 643 } 644 break; 645 case EXCP_UNKNOWN: 646 if (!undef_insn(0, frame)) 647 call_trapsignal(td, SIGILL, ILL_ILLTRP, (void *)far, 648 exception); 649 userret(td, frame); 650 break; 651 case EXCP_FPAC: 652 call_trapsignal(td, SIGILL, ILL_ILLOPN, (void *)frame->tf_elr, 653 exception); 654 userret(td, frame); 655 break; 656 case EXCP_SP_ALIGN: 657 call_trapsignal(td, SIGBUS, BUS_ADRALN, (void *)frame->tf_sp, 658 exception); 659 userret(td, frame); 660 break; 661 case EXCP_PC_ALIGN: 662 call_trapsignal(td, SIGBUS, BUS_ADRALN, (void *)frame->tf_elr, 663 exception); 664 userret(td, frame); 665 break; 666 case EXCP_BRKPT_EL0: 667 case EXCP_BRK: 668 #ifdef COMPAT_FREEBSD32 669 case EXCP_BRKPT_32: 670 #endif /* COMPAT_FREEBSD32 */ 671 call_trapsignal(td, SIGTRAP, TRAP_BRKPT, (void *)frame->tf_elr, 672 exception); 673 userret(td, frame); 674 break; 675 case EXCP_WATCHPT_EL0: 676 call_trapsignal(td, SIGTRAP, TRAP_TRACE, (void *)far, 677 exception); 678 userret(td, frame); 679 break; 680 case EXCP_MSR: 681 /* 682 * The CPU can raise EXCP_MSR when userspace executes an mrs 683 * instruction to access a special register userspace doesn't 684 * have access to. 685 */ 686 if (!undef_insn(0, frame)) 687 call_trapsignal(td, SIGILL, ILL_PRVOPC, 688 (void *)frame->tf_elr, exception); 689 userret(td, frame); 690 break; 691 case EXCP_SOFTSTP_EL0: 692 PROC_LOCK(td->td_proc); 693 if ((td->td_dbgflags & TDB_STEP) != 0) { 694 td->td_frame->tf_spsr &= ~PSR_SS; 695 td->td_pcb->pcb_flags &= ~PCB_SINGLE_STEP; 696 WRITE_SPECIALREG(mdscr_el1, 697 READ_SPECIALREG(mdscr_el1) & ~MDSCR_SS); 698 } 699 PROC_UNLOCK(td->td_proc); 700 call_trapsignal(td, SIGTRAP, TRAP_TRACE, 701 (void *)frame->tf_elr, exception); 702 userret(td, frame); 703 break; 704 default: 705 call_trapsignal(td, SIGBUS, BUS_OBJERR, (void *)frame->tf_elr, 706 exception); 707 userret(td, frame); 708 break; 709 } 710 711 KASSERT((td->td_pcb->pcb_fpflags & ~PCB_FP_USERMASK) == 0, 712 ("Kernel VFP flags set while entering userspace")); 713 KASSERT( 714 td->td_pcb->pcb_fpusaved == &td->td_pcb->pcb_fpustate, 715 ("Kernel VFP state in use when entering userspace")); 716 } 717 718 /* 719 * TODO: We will need to handle these later when we support ARMv8.2 RAS. 720 */ 721 void 722 do_serror(struct trapframe *frame) 723 { 724 uint64_t esr, far; 725 726 far = READ_SPECIALREG(far_el1); 727 esr = frame->tf_esr; 728 729 print_registers(frame); 730 print_gp_register("far", far); 731 printf(" esr: %.8lx\n", esr); 732 panic("Unhandled System Error"); 733 } 734 735 void 736 unhandled_exception(struct trapframe *frame) 737 { 738 uint64_t esr, far; 739 740 far = READ_SPECIALREG(far_el1); 741 esr = frame->tf_esr; 742 743 print_registers(frame); 744 print_gp_register("far", far); 745 printf(" esr: %.8lx\n", esr); 746 panic("Unhandled exception"); 747 } 748