2 * Copyright (c) 2014 Andrew Turner
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
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
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
31 #include <sys/param.h>
32 #include <sys/systm.h>
33 #include <sys/kernel.h>
36 #include <sys/mutex.h>
38 #include <sys/ptrace.h>
39 #include <sys/syscall.h>
40 #include <sys/sysent.h>
47 #include <vm/vm_kern.h>
48 #include <vm/vm_map.h>
49 #include <vm/vm_param.h>
50 #include <vm/vm_extern.h>
52 #include <machine/frame.h>
53 #include <machine/md_var.h>
54 #include <machine/pcb.h>
55 #include <machine/pcpu.h>
56 #include <machine/undefined.h>
59 #include <sys/dtrace_bsd.h>
63 #include <machine/vfp.h>
67 #include <machine/db_machdep.h>
71 #include <ddb/db_output.h>
74 extern register_t fsu_intr_fault;
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 *);
83 static void print_registers(struct trapframe *frame);
85 int (*dtrace_invop_jump_addr)(struct trapframe *);
87 typedef void (abort_handler)(struct thread *, struct trapframe *, uint64_t,
90 static abort_handler align_abort;
91 static abort_handler data_abort;
92 static abort_handler external_abort;
94 static abort_handler *abort_handlers[] = {
95 [ISS_DATA_DFSC_TF_L0] = data_abort,
96 [ISS_DATA_DFSC_TF_L1] = data_abort,
97 [ISS_DATA_DFSC_TF_L2] = data_abort,
98 [ISS_DATA_DFSC_TF_L3] = data_abort,
99 [ISS_DATA_DFSC_AFF_L1] = data_abort,
100 [ISS_DATA_DFSC_AFF_L2] = data_abort,
101 [ISS_DATA_DFSC_AFF_L3] = data_abort,
102 [ISS_DATA_DFSC_PF_L1] = data_abort,
103 [ISS_DATA_DFSC_PF_L2] = data_abort,
104 [ISS_DATA_DFSC_PF_L3] = data_abort,
105 [ISS_DATA_DFSC_ALIGN] = align_abort,
106 [ISS_DATA_DFSC_EXT] = external_abort,
110 call_trapsignal(struct thread *td, int sig, int code, void *addr, int trapno)
114 ksiginfo_init_trap(&ksi);
118 ksi.ksi_trapno = trapno;
119 trapsignal(td, &ksi);
123 cpu_fetch_syscall_args(struct thread *td)
126 register_t *ap, *dst_ap;
127 struct syscall_args *sa;
131 ap = td->td_frame->tf_x;
132 dst_ap = &sa->args[0];
134 sa->code = td->td_frame->tf_x[8];
136 if (__predict_false(sa->code == SYS_syscall || sa->code == SYS___syscall)) {
142 if (__predict_false(sa->code >= p->p_sysent->sv_size))
143 sa->callp = &p->p_sysent->sv_table[0];
145 sa->callp = &p->p_sysent->sv_table[sa->code];
147 KASSERT(sa->callp->sy_narg <= nitems(sa->args),
148 ("Syscall %d takes too many arguments", sa->code));
150 memcpy(dst_ap, ap, (MAXARGS - 1) * sizeof(register_t));
152 td->td_retval[0] = 0;
153 td->td_retval[1] = 0;
158 #include "../../kern/subr_syscall.c"
161 * Test for fault generated by given access instruction in
162 * bus_peek_<foo> or bus_poke_<foo> bus function.
164 extern uint32_t generic_bs_peek_1f, generic_bs_peek_2f;
165 extern uint32_t generic_bs_peek_4f, generic_bs_peek_8f;
166 extern uint32_t generic_bs_poke_1f, generic_bs_poke_2f;
167 extern uint32_t generic_bs_poke_4f, generic_bs_poke_8f;
170 test_bs_fault(void *addr)
172 return (addr == &generic_bs_peek_1f ||
173 addr == &generic_bs_peek_2f ||
174 addr == &generic_bs_peek_4f ||
175 addr == &generic_bs_peek_8f ||
176 addr == &generic_bs_poke_1f ||
177 addr == &generic_bs_poke_2f ||
178 addr == &generic_bs_poke_4f ||
179 addr == &generic_bs_poke_8f);
183 svc_handler(struct thread *td, struct trapframe *frame)
186 if ((frame->tf_esr & ESR_ELx_ISS_MASK) == 0) {
190 call_trapsignal(td, SIGILL, ILL_ILLOPN, (void *)frame->tf_elr,
191 ESR_ELx_EXCEPTION(frame->tf_esr));
197 align_abort(struct thread *td, struct trapframe *frame, uint64_t esr,
198 uint64_t far, int lower)
201 print_registers(frame);
202 printf(" far: %16lx\n", far);
203 printf(" esr: %.8lx\n", esr);
204 panic("Misaligned access from kernel space!");
207 call_trapsignal(td, SIGBUS, BUS_ADRALN, (void *)frame->tf_elr,
208 ESR_ELx_EXCEPTION(frame->tf_esr));
214 external_abort(struct thread *td, struct trapframe *frame, uint64_t esr,
215 uint64_t far, int lower)
219 * Try to handle synchronous external aborts caused by
220 * bus_space_peek() and/or bus_space_poke() functions.
222 if (!lower && test_bs_fault((void *)frame->tf_elr)) {
223 frame->tf_elr = (uint64_t)generic_bs_fault;
227 print_registers(frame);
228 printf(" far: %16lx\n", far);
229 panic("Unhandled EL%d external data abort", lower ? 0: 1);
233 data_abort(struct thread *td, struct trapframe *frame, uint64_t esr,
234 uint64_t far, int lower)
240 int error, sig, ucode;
246 * According to the ARMv8-A rev. A.g, B2.10.5 "Load-Exclusive
247 * and Store-Exclusive instruction usage restrictions", state
248 * of the exclusive monitors after data abort exception is unknown.
262 map = &p->p_vmspace->vm_map;
266 /* The top bit tells us which range to use */
267 if (far >= VM_MAXUSER_ADDRESS) {
270 map = &p->p_vmspace->vm_map;
277 * Try to handle translation, access flag, and permission faults.
278 * Translation faults may occur as a result of the required
279 * break-before-make sequence used when promoting or demoting
280 * superpages. Such faults must not occur while holding the pmap lock,
281 * or pmap_fault() will recurse on that lock.
283 if ((lower || map == kernel_map || pcb->pcb_onfault != 0) &&
284 pmap_fault(map->pmap, esr, far) == KERN_SUCCESS)
287 KASSERT(td->td_md.md_spinlock_count == 0,
288 ("data abort with spinlock held"));
289 if (td->td_critnest != 0 || WITNESS_CHECK(WARN_SLEEPOK |
290 WARN_GIANTOK, NULL, "Kernel page fault") != 0) {
291 print_registers(frame);
292 printf(" far: %16lx\n", far);
293 printf(" esr: %.8lx\n", esr);
294 panic("data abort in critical section or under mutex");
297 switch (ESR_ELx_EXCEPTION(esr)) {
298 case EXCP_INSN_ABORT:
299 case EXCP_INSN_ABORT_L:
300 ftype = VM_PROT_EXECUTE;
303 ftype = (esr & ISS_DATA_WnR) == 0 ? VM_PROT_READ :
308 /* Fault in the page. */
309 error = vm_fault_trap(map, far, ftype, VM_FAULT_NORMAL, &sig, &ucode);
310 if (error != KERN_SUCCESS) {
312 call_trapsignal(td, sig, ucode, (void *)far,
313 ESR_ELx_EXCEPTION(esr));
315 if (td->td_intr_nesting_level == 0 &&
316 pcb->pcb_onfault != 0) {
317 frame->tf_x[0] = error;
318 frame->tf_elr = pcb->pcb_onfault;
322 printf("Fatal data abort:\n");
323 print_registers(frame);
324 printf(" far: %16lx\n", far);
325 printf(" esr: %.8lx\n", esr);
328 if (debugger_on_trap) {
329 kdb_why = KDB_WHY_TRAP;
330 handled = kdb_trap(ESR_ELx_EXCEPTION(esr), 0,
332 kdb_why = KDB_WHY_UNSET;
337 panic("vm_fault failed: %lx", frame->tf_elr);
346 print_registers(struct trapframe *frame)
350 for (reg = 0; reg < nitems(frame->tf_x); reg++) {
351 printf(" %sx%d: %16lx\n", (reg < 10) ? " " : "", reg,
354 printf(" sp: %16lx\n", frame->tf_sp);
355 printf(" lr: %16lx\n", frame->tf_lr);
356 printf(" elr: %16lx\n", frame->tf_elr);
357 printf("spsr: %8x\n", frame->tf_spsr);
361 do_el1h_sync(struct thread *td, struct trapframe *frame)
363 struct trapframe *oframe;
368 /* Read the esr register to get the exception details */
370 exception = ESR_ELx_EXCEPTION(esr);
373 if (dtrace_trap_func != NULL && (*dtrace_trap_func)(frame, exception))
378 "do_el1_sync: curthread: %p, esr %lx, elr: %lx, frame: %p", td,
379 esr, frame->tf_elr, frame);
381 oframe = td->td_frame;
385 case EXCP_WATCHPT_EL1:
386 case EXCP_SOFTSTP_EL1:
389 td->td_frame = frame;
397 if ((td->td_pcb->pcb_fpflags & PCB_FP_KERN) != 0) {
402 print_registers(frame);
403 printf(" esr: %.8lx\n", esr);
404 panic("VFP exception in the kernel");
407 case EXCP_INSN_ABORT:
408 case EXCP_DATA_ABORT:
409 far = READ_SPECIALREG(far_el1);
410 dfsc = esr & ISS_DATA_DFSC_MASK;
411 if (dfsc < nitems(abort_handlers) &&
412 abort_handlers[dfsc] != NULL) {
413 abort_handlers[dfsc](td, frame, esr, far, 0);
415 print_registers(frame);
416 printf(" far: %16lx\n", far);
417 printf(" esr: %.8lx\n", esr);
418 panic("Unhandled EL1 %s abort: %x",
419 exception == EXCP_INSN_ABORT ? "instruction" :
425 if ((esr & ESR_ELx_ISS_MASK) == 0x40d && \
426 dtrace_invop_jump_addr != 0) {
427 dtrace_invop_jump_addr(frame);
432 kdb_trap(exception, 0,
433 (td->td_frame != NULL) ? td->td_frame : frame);
435 panic("No debugger in kernel.\n");
439 case EXCP_WATCHPT_EL1:
440 case EXCP_SOFTSTP_EL1:
442 kdb_trap(exception, 0,
443 (td->td_frame != NULL) ? td->td_frame : frame);
445 panic("No debugger in kernel.\n");
449 if (undef_insn(1, frame))
453 print_registers(frame);
454 printf(" far: %16lx\n", READ_SPECIALREG(far_el1));
455 panic("Unknown kernel exception %x esr_el1 %lx\n", exception,
459 td->td_frame = oframe;
463 do_el0_sync(struct thread *td, struct trapframe *frame)
465 pcpu_bp_harden bp_harden;
470 /* Check we have a sane environment when entering from userland */
471 KASSERT((uintptr_t)get_pcpu() >= VM_MIN_KERNEL_ADDRESS,
472 ("Invalid pcpu address from userland: %p (tpidr %lx)",
473 get_pcpu(), READ_SPECIALREG(tpidr_el1)));
476 exception = ESR_ELx_EXCEPTION(esr);
478 case EXCP_INSN_ABORT_L:
479 far = READ_SPECIALREG(far_el1);
482 * Userspace may be trying to train the branch predictor to
483 * attack the kernel. If we are on a CPU affected by this
484 * call the handler to clear the branch predictor state.
486 if (far > VM_MAXUSER_ADDRESS) {
487 bp_harden = PCPU_GET(bp_harden);
488 if (bp_harden != NULL)
493 case EXCP_DATA_ABORT_L:
494 case EXCP_DATA_ABORT:
495 far = READ_SPECIALREG(far_el1);
501 "do_el0_sync: curthread: %p, esr %lx, elr: %lx, frame: %p", td, esr,
502 frame->tf_elr, frame);
510 panic("VFP exception in userland");
515 svc_handler(td, frame);
517 case EXCP_INSN_ABORT_L:
518 case EXCP_DATA_ABORT_L:
519 case EXCP_DATA_ABORT:
520 dfsc = esr & ISS_DATA_DFSC_MASK;
521 if (dfsc < nitems(abort_handlers) &&
522 abort_handlers[dfsc] != NULL)
523 abort_handlers[dfsc](td, frame, esr, far, 1);
525 print_registers(frame);
526 printf(" far: %16lx\n", far);
527 printf(" esr: %.8lx\n", esr);
528 panic("Unhandled EL0 %s abort: %x",
529 exception == EXCP_INSN_ABORT_L ? "instruction" :
534 if (!undef_insn(0, frame))
535 call_trapsignal(td, SIGILL, ILL_ILLTRP, (void *)far,
540 call_trapsignal(td, SIGBUS, BUS_ADRALN, (void *)frame->tf_sp,
545 call_trapsignal(td, SIGBUS, BUS_ADRALN, (void *)frame->tf_elr,
551 call_trapsignal(td, SIGTRAP, TRAP_BRKPT, (void *)frame->tf_elr,
556 call_trapsignal(td, SIGILL, ILL_PRVOPC, (void *)frame->tf_elr,
560 case EXCP_SOFTSTP_EL0:
561 td->td_frame->tf_spsr &= ~PSR_SS;
562 td->td_pcb->pcb_flags &= ~PCB_SINGLE_STEP;
563 WRITE_SPECIALREG(mdscr_el1,
564 READ_SPECIALREG(mdscr_el1) & ~DBG_MDSCR_SS);
565 call_trapsignal(td, SIGTRAP, TRAP_TRACE,
566 (void *)frame->tf_elr, exception);
570 call_trapsignal(td, SIGBUS, BUS_OBJERR, (void *)frame->tf_elr,
576 KASSERT((td->td_pcb->pcb_fpflags & ~PCB_FP_USERMASK) == 0,
577 ("Kernel VFP flags set while entering userspace"));
579 td->td_pcb->pcb_fpusaved == &td->td_pcb->pcb_fpustate,
580 ("Kernel VFP state in use when entering userspace"));
584 * TODO: We will need to handle these later when we support ARMv8.2 RAS.
587 do_serror(struct trapframe *frame)
591 far = READ_SPECIALREG(far_el1);
594 print_registers(frame);
595 printf(" far: %16lx\n", far);
596 printf(" esr: %.8lx\n", esr);
597 panic("Unhandled System Error");
601 unhandled_exception(struct trapframe *frame)
605 far = READ_SPECIALREG(far_el1);
608 print_registers(frame);
609 printf(" far: %16lx\n", far);
610 printf(" esr: %.8lx\n", esr);
611 panic("Unhandled exception");