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/param.h>
31 #include <sys/systm.h>
32 #include <sys/asan.h>
33 #include <sys/kernel.h>
34 #include <sys/ktr.h>
35 #include <sys/lock.h>
36 #include <sys/msan.h>
37 #include <sys/mutex.h>
38 #include <sys/proc.h>
39 #include <sys/ptrace.h>
40 #include <sys/syscall.h>
41 #include <sys/sysent.h>
42 #ifdef KDB
43 #include <sys/kdb.h>
44 #endif
45
46 #include <vm/vm.h>
47 #include <vm/pmap.h>
48 #include <vm/vm_kern.h>
49 #include <vm/vm_map.h>
50 #include <vm/vm_param.h>
51 #include <vm/vm_extern.h>
52
53 #include <machine/frame.h>
54 #include <machine/md_var.h>
55 #include <machine/pcb.h>
56 #include <machine/pcpu.h>
57 #include <machine/undefined.h>
58
59 #ifdef KDTRACE_HOOKS
60 #include <sys/dtrace_bsd.h>
61 #endif
62
63 #ifdef VFP
64 #include <machine/vfp.h>
65 #endif
66
67 #ifdef KDB
68 #include <machine/db_machdep.h>
69 #endif
70
71 #ifdef DDB
72 #include <ddb/ddb.h>
73 #include <ddb/db_sym.h>
74 #endif
75
76 /* Called from exception.S */
77 void do_el1h_sync(struct thread *, struct trapframe *);
78 void do_el0_sync(struct thread *, struct trapframe *);
79 void do_el0_error(struct trapframe *);
80 void do_serror(struct trapframe *);
81 void unhandled_exception(struct trapframe *);
82
83 static void print_gp_register(const char *name, uint64_t value);
84 static void print_registers(struct trapframe *frame);
85
86 int (*dtrace_invop_jump_addr)(struct trapframe *);
87
88 typedef void (abort_handler)(struct thread *, struct trapframe *, uint64_t,
89 uint64_t, int);
90
91 static abort_handler align_abort;
92 static abort_handler data_abort;
93 static abort_handler external_abort;
94
95 static abort_handler *abort_handlers[] = {
96 [ISS_DATA_DFSC_TF_L0] = data_abort,
97 [ISS_DATA_DFSC_TF_L1] = data_abort,
98 [ISS_DATA_DFSC_TF_L2] = data_abort,
99 [ISS_DATA_DFSC_TF_L3] = data_abort,
100 [ISS_DATA_DFSC_AFF_L1] = data_abort,
101 [ISS_DATA_DFSC_AFF_L2] = data_abort,
102 [ISS_DATA_DFSC_AFF_L3] = data_abort,
103 [ISS_DATA_DFSC_PF_L1] = data_abort,
104 [ISS_DATA_DFSC_PF_L2] = data_abort,
105 [ISS_DATA_DFSC_PF_L3] = data_abort,
106 [ISS_DATA_DFSC_ALIGN] = align_abort,
107 [ISS_DATA_DFSC_EXT] = external_abort,
108 [ISS_DATA_DFSC_EXT_L0] = external_abort,
109 [ISS_DATA_DFSC_EXT_L1] = external_abort,
110 [ISS_DATA_DFSC_EXT_L2] = external_abort,
111 [ISS_DATA_DFSC_EXT_L3] = external_abort,
112 [ISS_DATA_DFSC_ECC] = external_abort,
113 [ISS_DATA_DFSC_ECC_L0] = external_abort,
114 [ISS_DATA_DFSC_ECC_L1] = external_abort,
115 [ISS_DATA_DFSC_ECC_L2] = external_abort,
116 [ISS_DATA_DFSC_ECC_L3] = external_abort,
117 };
118
119 static __inline void
call_trapsignal(struct thread * td,int sig,int code,void * addr,int trapno)120 call_trapsignal(struct thread *td, int sig, int code, void *addr, int trapno)
121 {
122 ksiginfo_t ksi;
123
124 ksiginfo_init_trap(&ksi);
125 ksi.ksi_signo = sig;
126 ksi.ksi_code = code;
127 ksi.ksi_addr = addr;
128 ksi.ksi_trapno = trapno;
129 trapsignal(td, &ksi);
130 }
131
132 int
cpu_fetch_syscall_args(struct thread * td)133 cpu_fetch_syscall_args(struct thread *td)
134 {
135 struct proc *p;
136 syscallarg_t *ap, *dst_ap;
137 struct syscall_args *sa;
138
139 p = td->td_proc;
140 sa = &td->td_sa;
141 ap = td->td_frame->tf_x;
142 dst_ap = &sa->args[0];
143
144 sa->code = td->td_frame->tf_x[8];
145 sa->original_code = sa->code;
146
147 if (__predict_false(sa->code == SYS_syscall || sa->code == SYS___syscall)) {
148 sa->code = *ap++;
149 } else {
150 *dst_ap++ = *ap++;
151 }
152
153 if (__predict_false(sa->code >= p->p_sysent->sv_size))
154 sa->callp = &nosys_sysent;
155 else
156 sa->callp = &p->p_sysent->sv_table[sa->code];
157
158 KASSERT(sa->callp->sy_narg <= nitems(sa->args),
159 ("Syscall %d takes too many arguments", sa->code));
160
161 memcpy(dst_ap, ap, (nitems(sa->args) - 1) * sizeof(*dst_ap));
162
163 td->td_retval[0] = 0;
164 td->td_retval[1] = 0;
165
166 return (0);
167 }
168
169 #include "../../kern/subr_syscall.c"
170
171 /*
172 * Test for fault generated by given access instruction in
173 * bus_peek_<foo> or bus_poke_<foo> bus function.
174 */
175 extern uint32_t generic_bs_peek_1f, generic_bs_peek_2f;
176 extern uint32_t generic_bs_peek_4f, generic_bs_peek_8f;
177 extern uint32_t generic_bs_poke_1f, generic_bs_poke_2f;
178 extern uint32_t generic_bs_poke_4f, generic_bs_poke_8f;
179
180 static bool
test_bs_fault(void * addr)181 test_bs_fault(void *addr)
182 {
183 return (addr == &generic_bs_peek_1f ||
184 addr == &generic_bs_peek_2f ||
185 addr == &generic_bs_peek_4f ||
186 addr == &generic_bs_peek_8f ||
187 addr == &generic_bs_poke_1f ||
188 addr == &generic_bs_poke_2f ||
189 addr == &generic_bs_poke_4f ||
190 addr == &generic_bs_poke_8f);
191 }
192
193 static void
svc_handler(struct thread * td,struct trapframe * frame)194 svc_handler(struct thread *td, struct trapframe *frame)
195 {
196
197 if ((frame->tf_esr & ESR_ELx_ISS_MASK) == 0) {
198 syscallenter(td);
199 syscallret(td);
200 } else {
201 call_trapsignal(td, SIGILL, ILL_ILLOPN, (void *)frame->tf_elr,
202 ESR_ELx_EXCEPTION(frame->tf_esr));
203 userret(td, frame);
204 }
205 }
206
207 static void
align_abort(struct thread * td,struct trapframe * frame,uint64_t esr,uint64_t far,int lower)208 align_abort(struct thread *td, struct trapframe *frame, uint64_t esr,
209 uint64_t far, int lower)
210 {
211 if (!lower) {
212 print_registers(frame);
213 print_gp_register("far", far);
214 printf(" esr: 0x%.16lx\n", esr);
215 panic("Misaligned access from kernel space!");
216 }
217
218 call_trapsignal(td, SIGBUS, BUS_ADRALN, (void *)frame->tf_elr,
219 ESR_ELx_EXCEPTION(frame->tf_esr));
220 userret(td, frame);
221 }
222
223
224 static void
external_abort(struct thread * td,struct trapframe * frame,uint64_t esr,uint64_t far,int lower)225 external_abort(struct thread *td, struct trapframe *frame, uint64_t esr,
226 uint64_t far, int lower)
227 {
228 if (lower) {
229 call_trapsignal(td, SIGBUS, BUS_OBJERR, (void *)far,
230 ESR_ELx_EXCEPTION(frame->tf_esr));
231 userret(td, frame);
232 return;
233 }
234
235 /*
236 * Try to handle synchronous external aborts caused by
237 * bus_space_peek() and/or bus_space_poke() functions.
238 */
239 if (test_bs_fault((void *)frame->tf_elr)) {
240 frame->tf_elr = (uint64_t)generic_bs_fault;
241 return;
242 }
243
244 print_registers(frame);
245 print_gp_register("far", far);
246 panic("Unhandled external data abort");
247 }
248
249 /*
250 * It is unsafe to access the stack canary value stored in "td" until
251 * kernel map translation faults are handled, see the pmap_klookup() call below.
252 * Thus, stack-smashing detection with per-thread canaries must be disabled in
253 * this function.
254 */
255 static void NO_PERTHREAD_SSP
data_abort(struct thread * td,struct trapframe * frame,uint64_t esr,uint64_t far,int lower)256 data_abort(struct thread *td, struct trapframe *frame, uint64_t esr,
257 uint64_t far, int lower)
258 {
259 struct vm_map *map;
260 struct pcb *pcb;
261 vm_prot_t ftype;
262 int error, sig, ucode;
263 #ifdef KDB
264 bool handled;
265 #endif
266
267 /*
268 * According to the ARMv8-A rev. A.g, B2.10.5 "Load-Exclusive
269 * and Store-Exclusive instruction usage restrictions", state
270 * of the exclusive monitors after data abort exception is unknown.
271 */
272 clrex();
273
274 #ifdef KDB
275 if (kdb_active) {
276 kdb_reenter();
277 return;
278 }
279 #endif
280
281 if (lower) {
282 map = &td->td_proc->p_vmspace->vm_map;
283 } else if (!ADDR_IS_CANONICAL(far)) {
284 /* We received a TBI/PAC/etc. fault from the kernel */
285 error = KERN_INVALID_ADDRESS;
286 pcb = td->td_pcb;
287 goto bad_far;
288 } else if (ADDR_IS_KERNEL(far)) {
289 /*
290 * Handle a special case: the data abort was caused by accessing
291 * a thread structure while its mapping was being promoted or
292 * demoted, as a consequence of the break-before-make rule. It
293 * is not safe to enable interrupts or dereference "td" before
294 * this case is handled.
295 *
296 * In principle, if pmap_klookup() fails, there is no need to
297 * call pmap_fault() below, but avoiding that call is not worth
298 * the effort.
299 */
300 if (ESR_ELx_EXCEPTION(esr) == EXCP_DATA_ABORT) {
301 switch (esr & ISS_DATA_DFSC_MASK) {
302 case ISS_DATA_DFSC_TF_L0:
303 case ISS_DATA_DFSC_TF_L1:
304 case ISS_DATA_DFSC_TF_L2:
305 case ISS_DATA_DFSC_TF_L3:
306 if (pmap_klookup(far, NULL))
307 return;
308 break;
309 }
310 }
311 intr_enable();
312 map = kernel_map;
313 } else {
314 intr_enable();
315 map = &td->td_proc->p_vmspace->vm_map;
316 if (map == NULL)
317 map = kernel_map;
318 }
319 pcb = td->td_pcb;
320
321 /*
322 * Try to handle translation, access flag, and permission faults.
323 * Translation faults may occur as a result of the required
324 * break-before-make sequence used when promoting or demoting
325 * superpages. Such faults must not occur while holding the pmap lock,
326 * or pmap_fault() will recurse on that lock.
327 */
328 if ((lower || map == kernel_map || pcb->pcb_onfault != 0) &&
329 pmap_fault(map->pmap, esr, far) == KERN_SUCCESS)
330 return;
331
332 #ifdef INVARIANTS
333 if (td->td_md.md_spinlock_count != 0) {
334 print_registers(frame);
335 print_gp_register("far", far);
336 printf(" esr: 0x%.16lx\n", esr);
337 panic("data abort with spinlock held (spinlock count %d != 0)",
338 td->td_md.md_spinlock_count);
339 }
340 #endif
341 if (td->td_critnest != 0 || WITNESS_CHECK(WARN_SLEEPOK |
342 WARN_GIANTOK, NULL, "Kernel page fault") != 0) {
343 print_registers(frame);
344 print_gp_register("far", far);
345 printf(" esr: 0x%.16lx\n", esr);
346 panic("data abort in critical section or under mutex");
347 }
348
349 switch (ESR_ELx_EXCEPTION(esr)) {
350 case EXCP_INSN_ABORT:
351 case EXCP_INSN_ABORT_L:
352 ftype = VM_PROT_EXECUTE;
353 break;
354 default:
355 /*
356 * If the exception was because of a read or cache operation
357 * pass a read fault type into the vm code. Cache operations
358 * need read permission but will set the WnR flag when the
359 * memory is unmapped.
360 */
361 if ((esr & ISS_DATA_WnR) == 0 || (esr & ISS_DATA_CM) != 0)
362 ftype = VM_PROT_READ;
363 else
364 ftype = VM_PROT_WRITE;
365 break;
366 }
367
368 /* Fault in the page. */
369 error = vm_fault_trap(map, far, ftype, VM_FAULT_NORMAL, &sig, &ucode);
370 if (error != KERN_SUCCESS) {
371 if (lower) {
372 call_trapsignal(td, sig, ucode, (void *)far,
373 ESR_ELx_EXCEPTION(esr));
374 } else {
375 bad_far:
376 if (td->td_intr_nesting_level == 0 &&
377 pcb->pcb_onfault != 0) {
378 frame->tf_x[0] = error;
379 frame->tf_elr = pcb->pcb_onfault;
380 return;
381 }
382
383 printf("Fatal data abort:\n");
384 print_registers(frame);
385 print_gp_register("far", far);
386 printf(" esr: 0x%.16lx\n", esr);
387
388 #ifdef KDB
389 if (debugger_on_trap) {
390 kdb_why = KDB_WHY_TRAP;
391 handled = kdb_trap(ESR_ELx_EXCEPTION(esr), 0,
392 frame);
393 kdb_why = KDB_WHY_UNSET;
394 if (handled)
395 return;
396 }
397 #endif
398 panic("vm_fault failed: 0x%lx error %d",
399 frame->tf_elr, error);
400 }
401 }
402
403 if (lower)
404 userret(td, frame);
405 }
406
407 static void
print_gp_register(const char * name,uint64_t value)408 print_gp_register(const char *name, uint64_t value)
409 {
410 #if defined(DDB)
411 c_db_sym_t sym;
412 const char *sym_name;
413 db_expr_t sym_value;
414 db_expr_t offset;
415 #endif
416
417 printf(" %s: 0x%.16lx", name, value);
418 #if defined(DDB)
419 /* If this looks like a kernel address try to find the symbol */
420 if (value >= VM_MIN_KERNEL_ADDRESS) {
421 sym = db_search_symbol(value, DB_STGY_ANY, &offset);
422 if (sym != C_DB_SYM_NULL) {
423 db_symbol_values(sym, &sym_name, &sym_value);
424 printf(" (%s + 0x%lx)", sym_name, offset);
425 }
426 }
427 #endif
428 printf("\n");
429 }
430
431 static void
print_registers(struct trapframe * frame)432 print_registers(struct trapframe *frame)
433 {
434 char name[4];
435 u_int reg;
436
437 for (reg = 0; reg < nitems(frame->tf_x); reg++) {
438 snprintf(name, sizeof(name), "%sx%d", (reg < 10) ? " " : "",
439 reg);
440 print_gp_register(name, frame->tf_x[reg]);
441 }
442 printf(" sp: 0x%.16lx\n", frame->tf_sp);
443 print_gp_register(" lr", frame->tf_lr);
444 print_gp_register("elr", frame->tf_elr);
445 printf("spsr: 0x%.16lx\n", frame->tf_spsr);
446 }
447
448 #ifdef VFP
449 static void
fpe_trap(struct thread * td,void * addr,uint32_t exception)450 fpe_trap(struct thread *td, void *addr, uint32_t exception)
451 {
452 int code;
453
454 code = FPE_FLTIDO;
455 if ((exception & ISS_FP_TFV) != 0) {
456 if ((exception & ISS_FP_IOF) != 0)
457 code = FPE_FLTINV;
458 else if ((exception & ISS_FP_DZF) != 0)
459 code = FPE_FLTDIV;
460 else if ((exception & ISS_FP_OFF) != 0)
461 code = FPE_FLTOVF;
462 else if ((exception & ISS_FP_UFF) != 0)
463 code = FPE_FLTUND;
464 else if ((exception & ISS_FP_IXF) != 0)
465 code = FPE_FLTRES;
466 }
467 call_trapsignal(td, SIGFPE, code, addr, exception);
468 }
469 #endif
470
471 /*
472 * See the comment above data_abort().
473 */
474 void NO_PERTHREAD_SSP
do_el1h_sync(struct thread * td,struct trapframe * frame)475 do_el1h_sync(struct thread *td, struct trapframe *frame)
476 {
477 uint32_t exception;
478 uint64_t esr, far;
479 int dfsc;
480
481 kasan_mark(frame, sizeof(*frame), sizeof(*frame), 0);
482 kmsan_mark(frame, sizeof(*frame), KMSAN_STATE_INITED);
483
484 far = frame->tf_far;
485 /* Read the esr register to get the exception details */
486 esr = frame->tf_esr;
487 exception = ESR_ELx_EXCEPTION(esr);
488
489 #ifdef KDTRACE_HOOKS
490 if (dtrace_trap_func != NULL && (*dtrace_trap_func)(frame, exception))
491 return;
492 #endif
493
494 CTR4(KTR_TRAP, "%s: exception=%lu, elr=0x%lx, esr=0x%lx",
495 __func__, exception, frame->tf_elr, esr);
496
497 /*
498 * Enable debug exceptions if we aren't already handling one. They will
499 * be masked again in the exception handler's epilogue.
500 */
501 switch (exception) {
502 case EXCP_BRK:
503 case EXCP_BRKPT_EL1:
504 case EXCP_WATCHPT_EL1:
505 case EXCP_SOFTSTP_EL1:
506 break;
507 default:
508 dbg_enable();
509 break;
510 }
511
512 switch (exception) {
513 case EXCP_FP_SIMD:
514 case EXCP_TRAP_FP:
515 #ifdef VFP
516 if ((td->td_pcb->pcb_fpflags & PCB_FP_KERN) != 0) {
517 vfp_restore_state();
518 } else
519 #endif
520 {
521 print_registers(frame);
522 printf(" esr: 0x%.16lx\n", esr);
523 panic("VFP exception in the kernel");
524 }
525 break;
526 case EXCP_INSN_ABORT:
527 case EXCP_DATA_ABORT:
528 dfsc = esr & ISS_DATA_DFSC_MASK;
529 if (dfsc < nitems(abort_handlers) &&
530 abort_handlers[dfsc] != NULL) {
531 abort_handlers[dfsc](td, frame, esr, far, 0);
532 } else {
533 print_registers(frame);
534 print_gp_register("far", far);
535 printf(" esr: 0x%.16lx\n", esr);
536 panic("Unhandled EL1 %s abort: 0x%x",
537 exception == EXCP_INSN_ABORT ? "instruction" :
538 "data", dfsc);
539 }
540 break;
541 case EXCP_BRK:
542 #ifdef KDTRACE_HOOKS
543 if ((esr & ESR_ELx_ISS_MASK) == 0x40d && \
544 dtrace_invop_jump_addr != 0) {
545 dtrace_invop_jump_addr(frame);
546 break;
547 }
548 #endif
549 #ifdef KDB
550 kdb_trap(exception, 0, frame);
551 #else
552 panic("No debugger in kernel.");
553 #endif
554 break;
555 case EXCP_BRKPT_EL1:
556 case EXCP_WATCHPT_EL1:
557 case EXCP_SOFTSTP_EL1:
558 #ifdef KDB
559 kdb_trap(exception, 0, frame);
560 #else
561 panic("No debugger in kernel.");
562 #endif
563 break;
564 case EXCP_FPAC:
565 /* We can see this if the authentication on PAC fails */
566 print_registers(frame);
567 print_gp_register("far", far);
568 panic("FPAC kernel exception");
569 break;
570 case EXCP_UNKNOWN:
571 if (undef_insn(1, frame))
572 break;
573 print_registers(frame);
574 print_gp_register("far", far);
575 panic("Undefined instruction: %08x",
576 *(uint32_t *)frame->tf_elr);
577 break;
578 case EXCP_BTI:
579 print_registers(frame);
580 print_gp_register("far", far);
581 panic("Branch Target exception");
582 break;
583 default:
584 print_registers(frame);
585 print_gp_register("far", far);
586 panic("Unknown kernel exception 0x%x esr_el1 0x%lx", exception,
587 esr);
588 }
589 }
590
591 void
do_el0_sync(struct thread * td,struct trapframe * frame)592 do_el0_sync(struct thread *td, struct trapframe *frame)
593 {
594 pcpu_bp_harden bp_harden;
595 uint32_t exception;
596 uint64_t esr, far;
597 int dfsc;
598
599 /* Check we have a sane environment when entering from userland */
600 KASSERT((uintptr_t)get_pcpu() >= VM_MIN_KERNEL_ADDRESS,
601 ("Invalid pcpu address from userland: %p (tpidr 0x%lx)",
602 get_pcpu(), READ_SPECIALREG(tpidr_el1)));
603
604 kasan_mark(frame, sizeof(*frame), sizeof(*frame), 0);
605 kmsan_mark(frame, sizeof(*frame), KMSAN_STATE_INITED);
606
607 far = frame->tf_far;
608 esr = frame->tf_esr;
609 exception = ESR_ELx_EXCEPTION(esr);
610 if (exception == EXCP_INSN_ABORT_L && far > VM_MAXUSER_ADDRESS) {
611 /*
612 * Userspace may be trying to train the branch predictor to
613 * attack the kernel. If we are on a CPU affected by this
614 * call the handler to clear the branch predictor state.
615 */
616 bp_harden = PCPU_GET(bp_harden);
617 if (bp_harden != NULL)
618 bp_harden();
619 }
620 intr_enable();
621
622 CTR4(KTR_TRAP, "%s: exception=%lu, elr=0x%lx, esr=0x%lx",
623 __func__, exception, frame->tf_elr, esr);
624
625 switch (exception) {
626 case EXCP_FP_SIMD:
627 #ifdef VFP
628 vfp_restore_state();
629 #else
630 panic("VFP exception in userland");
631 #endif
632 break;
633 case EXCP_TRAP_FP:
634 #ifdef VFP
635 fpe_trap(td, (void *)frame->tf_elr, esr);
636 userret(td, frame);
637 #else
638 panic("VFP exception in userland");
639 #endif
640 break;
641 case EXCP_SVE:
642 call_trapsignal(td, SIGILL, ILL_ILLTRP, (void *)frame->tf_elr,
643 exception);
644 userret(td, frame);
645 break;
646 case EXCP_SVC32:
647 case EXCP_SVC64:
648 svc_handler(td, frame);
649 break;
650 case EXCP_INSN_ABORT_L:
651 case EXCP_DATA_ABORT_L:
652 case EXCP_DATA_ABORT:
653 dfsc = esr & ISS_DATA_DFSC_MASK;
654 if (dfsc < nitems(abort_handlers) &&
655 abort_handlers[dfsc] != NULL)
656 abort_handlers[dfsc](td, frame, esr, far, 1);
657 else {
658 print_registers(frame);
659 print_gp_register("far", far);
660 printf(" esr: 0x%.16lx\n", esr);
661 panic("Unhandled EL0 %s abort: 0x%x",
662 exception == EXCP_INSN_ABORT_L ? "instruction" :
663 "data", dfsc);
664 }
665 break;
666 case EXCP_UNKNOWN:
667 if (!undef_insn(0, frame))
668 call_trapsignal(td, SIGILL, ILL_ILLTRP, (void *)far,
669 exception);
670 userret(td, frame);
671 break;
672 case EXCP_FPAC:
673 call_trapsignal(td, SIGILL, ILL_ILLOPN, (void *)frame->tf_elr,
674 exception);
675 userret(td, frame);
676 break;
677 case EXCP_SP_ALIGN:
678 call_trapsignal(td, SIGBUS, BUS_ADRALN, (void *)frame->tf_sp,
679 exception);
680 userret(td, frame);
681 break;
682 case EXCP_PC_ALIGN:
683 call_trapsignal(td, SIGBUS, BUS_ADRALN, (void *)frame->tf_elr,
684 exception);
685 userret(td, frame);
686 break;
687 case EXCP_BRKPT_EL0:
688 case EXCP_BRK:
689 #ifdef COMPAT_FREEBSD32
690 case EXCP_BRKPT_32:
691 #endif /* COMPAT_FREEBSD32 */
692 call_trapsignal(td, SIGTRAP, TRAP_BRKPT, (void *)frame->tf_elr,
693 exception);
694 userret(td, frame);
695 break;
696 case EXCP_WATCHPT_EL0:
697 call_trapsignal(td, SIGTRAP, TRAP_TRACE, (void *)far,
698 exception);
699 userret(td, frame);
700 break;
701 case EXCP_MSR:
702 /*
703 * The CPU can raise EXCP_MSR when userspace executes an mrs
704 * instruction to access a special register userspace doesn't
705 * have access to.
706 */
707 if (!undef_insn(0, frame))
708 call_trapsignal(td, SIGILL, ILL_PRVOPC,
709 (void *)frame->tf_elr, exception);
710 userret(td, frame);
711 break;
712 case EXCP_SOFTSTP_EL0:
713 PROC_LOCK(td->td_proc);
714 if ((td->td_dbgflags & TDB_STEP) != 0) {
715 td->td_frame->tf_spsr &= ~PSR_SS;
716 td->td_pcb->pcb_flags &= ~PCB_SINGLE_STEP;
717 WRITE_SPECIALREG(mdscr_el1,
718 READ_SPECIALREG(mdscr_el1) & ~MDSCR_SS);
719 }
720 PROC_UNLOCK(td->td_proc);
721 call_trapsignal(td, SIGTRAP, TRAP_TRACE,
722 (void *)frame->tf_elr, exception);
723 userret(td, frame);
724 break;
725 case EXCP_BTI:
726 call_trapsignal(td, SIGILL, ILL_ILLOPC, (void *)frame->tf_elr,
727 exception);
728 userret(td, frame);
729 break;
730 default:
731 call_trapsignal(td, SIGBUS, BUS_OBJERR, (void *)frame->tf_elr,
732 exception);
733 userret(td, frame);
734 break;
735 }
736
737 KASSERT((td->td_pcb->pcb_fpflags & ~PCB_FP_USERMASK) == 0,
738 ("Kernel VFP flags set while entering userspace"));
739 KASSERT(
740 td->td_pcb->pcb_fpusaved == &td->td_pcb->pcb_fpustate,
741 ("Kernel VFP state in use when entering userspace"));
742 }
743
744 /*
745 * TODO: We will need to handle these later when we support ARMv8.2 RAS.
746 */
747 void
do_serror(struct trapframe * frame)748 do_serror(struct trapframe *frame)
749 {
750 uint64_t esr, far;
751
752 kasan_mark(frame, sizeof(*frame), sizeof(*frame), 0);
753 kmsan_mark(frame, sizeof(*frame), KMSAN_STATE_INITED);
754
755 far = frame->tf_far;
756 esr = frame->tf_esr;
757
758 print_registers(frame);
759 print_gp_register("far", far);
760 printf(" esr: 0x%.16lx\n", esr);
761 panic("Unhandled System Error");
762 }
763
764 void
unhandled_exception(struct trapframe * frame)765 unhandled_exception(struct trapframe *frame)
766 {
767 uint64_t esr, far;
768
769 kasan_mark(frame, sizeof(*frame), sizeof(*frame), 0);
770 kmsan_mark(frame, sizeof(*frame), KMSAN_STATE_INITED);
771
772 far = frame->tf_far;
773 esr = frame->tf_esr;
774
775 print_registers(frame);
776 print_gp_register("far", far);
777 printf(" esr: 0x%.16lx\n", esr);
778 panic("Unhandled exception");
779 }
780