1/* $NetBSD: trap.c,v 1.87 2016/10/26 22:02:14 christos Exp $ */
2
3/*-
4 * Copyright (c) 1998, 2000 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Charles M. Hannum.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32/*-
33 * Copyright (c) 1990 The Regents of the University of California.
34 * All rights reserved.
35 *
36 * This code is derived from software contributed to Berkeley by
37 * the University of Utah, and William Jolitz.
38 *
39 * Redistribution and use in source and binary forms, with or without
40 * modification, are permitted provided that the following conditions
41 * are met:
42 * 1. Redistributions of source code must retain the above copyright
43 * notice, this list of conditions and the following disclaimer.
44 * 2. Redistributions in binary form must reproduce the above copyright
45 * notice, this list of conditions and the following disclaimer in the
46 * documentation and/or other materials provided with the distribution.
47 * 3. Neither the name of the University nor the names of its contributors
48 * may be used to endorse or promote products derived from this software
49 * without specific prior written permission.
50 *
51 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
52 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
53 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
54 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
55 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
56 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
57 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
58 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
59 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
60 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
61 * SUCH DAMAGE.
62 *
63 * @(#)trap.c 7.4 (Berkeley) 5/13/91
64 */
65
66/*
67 * 386 Trap and System call handling
68 */
69
70#include <sys/cdefs.h>
71__KERNEL_RCSID(0, "$NetBSD: trap.c,v 1.87 2016/10/26 22:02:14 christos Exp $");
72
73#include "opt_ddb.h"
74#include "opt_kgdb.h"
75#include "opt_xen.h"
76#include "opt_dtrace.h"
77
78#include <sys/param.h>
79#include <sys/systm.h>
80#include <sys/proc.h>
81#include <sys/acct.h>
82#include <sys/kauth.h>
83#include <sys/kernel.h>
84#include <sys/kmem.h>
85#include <sys/ras.h>
86#include <sys/signal.h>
87#include <sys/syscall.h>
88#include <sys/cpu.h>
89#include <sys/ucontext.h>
90
91#include <uvm/uvm_extern.h>
92
93#include <machine/cpufunc.h>
94#include <x86/fpu.h>
95#include <machine/psl.h>
96#include <machine/reg.h>
97#include <machine/trap.h>
98#include <machine/userret.h>
99#include <machine/db_machdep.h>
100
101#include <x86/nmi.h>
102
103#ifndef XEN
104#include "isa.h"
105#endif
106
107#include <sys/kgdb.h>
108
109#ifdef KDTRACE_HOOKS
110#include <sys/dtrace_bsd.h>
111
112/*
113 * This is a hook which is initialized by the dtrace module
114 * to handle traps which might occur during DTrace probe
115 * execution.
116 */
117dtrace_trap_func_t dtrace_trap_func = NULL;
118
119dtrace_doubletrap_func_t dtrace_doubletrap_func = NULL;
120#endif
121
122void trap(struct trapframe *);
123void trap_return_fault_return(struct trapframe *) __dead;
124
125const char * const trap_type[] = {
126 "privileged instruction fault", /* 0 T_PRIVINFLT */
127 "breakpoint trap", /* 1 T_BPTFLT */
128 "arithmetic trap", /* 2 T_ARITHTRAP */
129 "asynchronous system trap", /* 3 T_ASTFLT */
130 "protection fault", /* 4 T_PROTFLT */
131 "trace trap", /* 5 T_TRCTRAP */
132 "page fault", /* 6 T_PAGEFLT */
133 "alignment fault", /* 7 T_ALIGNFLT */
134 "integer divide fault", /* 8 T_DIVIDE */
135 "non-maskable interrupt", /* 9 T_NMI */
136 "overflow trap", /* 10 T_OFLOW */
137 "bounds check fault", /* 11 T_BOUND */
138 "FPU not available fault", /* 12 T_DNA */
139 "double fault", /* 13 T_DOUBLEFLT */
140 "FPU operand fetch fault", /* 14 T_FPOPFLT */
141 "invalid TSS fault", /* 15 T_TSSFLT */
142 "segment not present fault", /* 16 T_SEGNPFLT */
143 "stack fault", /* 17 T_STKFLT */
144 "machine check fault", /* 18 T_MCA */
145 "SSE FP exception", /* 19 T_XMM */
146 "reserved trap", /* 20 T_RESERVED */
147};
148int trap_types = __arraycount(trap_type);
149
150#ifdef DEBUG
151int trapdebug = 0;
152#endif
153
154#define IDTVEC(name) __CONCAT(X, name)
155
156#ifdef TRAP_SIGDEBUG
157static void frame_dump(struct trapframe *);
158#endif
159
160static void *
161onfault_handler(const struct pcb *pcb, const struct trapframe *tf)
162{
163 struct onfault_table {
164 uintptr_t start;
165 uintptr_t end;
166 void *handler;
167 };
168 extern const struct onfault_table onfault_table[];
169 const struct onfault_table *p;
170 uintptr_t pc;
171
172 if (pcb->pcb_onfault != NULL) {
173 return pcb->pcb_onfault;
174 }
175
176 pc = tf->tf_rip;
177 for (p = onfault_table; p->start; p++) {
178 if (p->start <= pc && pc < p->end) {
179 return p->handler;
180 }
181 }
182 return NULL;
183}
184
185static void
186trap_print(const struct trapframe *frame, const lwp_t *l)
187{
188 const int type = frame->tf_trapno;
189
190 if (frame->tf_trapno < trap_types) {
191 printf("fatal %s", trap_type[type]);
192 } else {
193 printf("unknown trap %d", type);
194 }
195 printf(" in %s mode\n", (type & T_USER) ? "user" : "supervisor");
196
197 printf("trap type %d code %lx rip %lx cs %lx rflags %lx cr2 %lx "
198 "ilevel %x rsp %lx\n",
199 type, frame->tf_err, (u_long)frame->tf_rip, frame->tf_cs,
200 frame->tf_rflags, rcr2(), curcpu()->ci_ilevel, frame->tf_rsp);
201
202 printf("curlwp %p pid %d.%d lowest kstack %p\n",
203 l, l->l_proc->p_pid, l->l_lid, KSTACK_LOWEST_ADDR(l));
204}
205
206/*
207 * trap(frame): exception, fault, and trap interface to BSD kernel.
208 *
209 * This common code is called from assembly language IDT gate entry routines
210 * that prepare a suitable stack frame, and restore this frame after the
211 * exception has been processed. Note that the effect is as if the arguments
212 * were passed call by reference.
213 *
214 * Note that the fpu traps (07 T_DNA, 10 T_ARITHTRAP and 13 T_XMM)
215 * jump directly into the code in x86/fpu.c so they get processed
216 * without interrupts being enabled.
217 */
218void
219trap(struct trapframe *frame)
220{
221 struct lwp *l = curlwp;
222 struct proc *p;
223 struct pcb *pcb;
224 extern char fusuintrfailure[], kcopy_fault[];
225 extern char IDTVEC(oosyscall)[];
226 extern char IDTVEC(osyscall)[];
227 extern char IDTVEC(syscall32)[];
228#ifndef XEN
229 struct trapframe *vframe;
230#endif
231 ksiginfo_t ksi;
232 void *onfault;
233 int type, error;
234 uint64_t cr2;
235 bool pfail;
236
237 if (__predict_true(l != NULL)) {
238 pcb = lwp_getpcb(l);
239 p = l->l_proc;
240 } else {
241 /*
242 * this can happen eg. on break points in early on boot.
243 */
244 pcb = NULL;
245 p = NULL;
246 }
247 type = frame->tf_trapno;
248
249#ifdef DEBUG
250 if (trapdebug) {
251 trap_print(frame, l);
252 }
253#endif
254 if (type != T_NMI && !KERNELMODE(frame->tf_cs, frame->tf_rflags)) {
255 type |= T_USER;
256 l->l_md.md_regs = frame;
257 LWP_CACHE_CREDS(l, p);
258 }
259
260#ifdef KDTRACE_HOOKS
261 /*
262 * A trap can occur while DTrace executes a probe. Before
263 * executing the probe, DTrace blocks re-scheduling and sets
264 * a flag in its per-cpu flags to indicate that it doesn't
265 * want to fault. On returning from the the probe, the no-fault
266 * flag is cleared and finally re-scheduling is enabled.
267 *
268 * If the DTrace kernel module has registered a trap handler,
269 * call it and if it returns non-zero, assume that it has
270 * handled the trap and modified the trap frame so that this
271 * function can return normally.
272 */
273 if ((type == T_PROTFLT || type == T_PAGEFLT) &&
274 dtrace_trap_func != NULL) {
275 if ((*dtrace_trap_func)(frame, type)) {
276 return;
277 }
278 }
279#endif
280
281 switch (type) {
282
283 default:
284 we_re_toast:
285 trap_print(frame, l);
286
287 if (kdb_trap(type, 0, frame))
288 return;
289 if (kgdb_trap(type, frame))
290 return;
291 /*
292 * If this is a breakpoint, don't panic if we're not connected.
293 */
294 if (type == T_BPTFLT && kgdb_disconnected()) {
295 printf("kgdb: ignored %s\n", trap_type[type]);
296 return;
297 }
298 panic("trap");
299 /*NOTREACHED*/
300
301 case T_PROTFLT:
302 case T_SEGNPFLT:
303 case T_ALIGNFLT:
304 case T_TSSFLT:
305 if (p == NULL)
306 goto we_re_toast;
307 /* Check for copyin/copyout fault. */
308 onfault = onfault_handler(pcb, frame);
309 if (onfault != NULL) {
310copyefault:
311 error = EFAULT;
312copyfault:
313 frame->tf_rip = (uintptr_t)onfault;
314 frame->tf_rax = error;
315 return;
316 }
317
318 /*
319 * Check for failure during return to user mode.
320 * This can happen loading invalid values into the segment
321 * registers, or during the 'iret' itself.
322 *
323 * We do this by looking at the instruction we faulted on.
324 * The specific instructions we recognize only happen when
325 * returning from a trap, syscall, or interrupt.
326 */
327
328kernelfault:
329#ifdef XEN
330 /*
331 * XXX: there has to be an equivalent 'problem'
332 * but I (dsl) don't know exactly what happens!
333 * For now panic the kernel.
334 */
335 goto we_re_toast;
336#else
337 KSI_INIT_TRAP(&ksi);
338 ksi.ksi_signo = SIGSEGV;
339 ksi.ksi_code = SEGV_ACCERR;
340 ksi.ksi_trap = type;
341
342 /* Get %rsp value before fault - there may be a pad word
343 * below the trap frame. */
344 vframe = (void *)frame->tf_rsp;
345 if (frame->tf_rip == 0) {
346 /*
347 * Assume that if we jumped to null we
348 * probably did it via a null function
349 * pointer, so print the return address.
350 */
351 printf("kernel jumped to null; return addr was %p\n",
352 *(void **)frame->tf_rsp);
353 goto we_re_toast;
354 }
355 switch (*(uint16_t *)frame->tf_rip) {
356 case 0xcf48: /* iretq */
357 /*
358 * The 'iretq' instruction faulted, so we have the
359 * 'user' registers saved after the kernel
360 * %rip:%cs:%fl:%rsp:%ss of the iret, and below that
361 * the user %rip:%cs:%fl:%rsp:%ss the 'iret' was
362 * processing.
363 * We must copy the user register back over the
364 * kernel fault frame to generate a normal stack
365 * frame (eg for sending a SIGSEGV).
366 */
367 vframe = (void *)((char *)vframe
368 - offsetof(struct trapframe, tf_rip));
369 memmove(vframe, frame,
370 offsetof(struct trapframe, tf_rip));
371 /* Set the faulting address to the user %eip */
372 ksi.ksi_addr = (void *)vframe->tf_rip;
373 break;
374 case 0x848e: /* mov 0xa8(%rsp),%es (8e 84 24 a8 00 00 00) */
375 case 0x9c8e: /* mov 0xb0(%rsp),%ds (8e 9c 24 b0 00 00 00) */
376 /*
377 * We faulted loading one of the user segment registers.
378 * The stack frame containing the user registers is
379 * still valid and pointed to by tf_rsp.
380 * Maybe we should check the iretq follows.
381 */
382 if (KERNELMODE(vframe->tf_cs, vframe->tf_eflags))
383 goto we_re_toast;
384 /* There is no valid address for the fault */
385 break;
386
387 default:
388 goto we_re_toast;
389 }
390
391 /* XXX: worry about on-stack trampolines for nested
392 * handlers?? */
393 /* Save outer frame for any signal return */
394 l->l_md.md_regs = vframe;
395 (*p->p_emul->e_trapsignal)(l, &ksi);
396 /* Return to user by reloading the user frame */
397 trap_return_fault_return(vframe);
398 /* NOTREACHED */
399#endif
400
401 case T_PROTFLT|T_USER: /* protection fault */
402 case T_TSSFLT|T_USER:
403 case T_SEGNPFLT|T_USER:
404 case T_STKFLT|T_USER:
405 case T_ALIGNFLT|T_USER:
406#ifdef TRAP_SIGDEBUG
407 printf("pid %d.%d (%s): BUS/SEGV (%x) at rip %lx addr %lx\n",
408 p->p_pid, l->l_lid, p->p_comm, type, frame->tf_rip, rcr2());
409 frame_dump(frame);
410#endif
411 KSI_INIT_TRAP(&ksi);
412 ksi.ksi_trap = type & ~T_USER;
413 ksi.ksi_addr = (void *)rcr2();
414 switch (type) {
415 case T_SEGNPFLT|T_USER:
416 case T_STKFLT|T_USER:
417 ksi.ksi_signo = SIGBUS;
418 ksi.ksi_code = BUS_ADRERR;
419 break;
420 case T_TSSFLT|T_USER:
421 ksi.ksi_signo = SIGBUS;
422 ksi.ksi_code = BUS_OBJERR;
423 break;
424 case T_ALIGNFLT|T_USER:
425 ksi.ksi_signo = SIGBUS;
426 ksi.ksi_code = BUS_ADRALN;
427 break;
428 case T_PROTFLT|T_USER:
429 ksi.ksi_signo = SIGSEGV;
430 ksi.ksi_code = SEGV_ACCERR;
431 break;
432 default:
433 KASSERT(0);
434 break;
435 }
436 goto trapsignal;
437
438 case T_PRIVINFLT|T_USER: /* privileged instruction fault */
439 case T_FPOPFLT|T_USER: /* coprocessor operand fault */
440#ifdef TRAP_SIGDEBUG
441 printf("pid %d.%d (%s): ILL at rip %lx addr %lx\n",
442 p->p_pid, l->l_lid, p->p_comm, frame->tf_rip, rcr2());
443 frame_dump(frame);
444#endif
445 KSI_INIT_TRAP(&ksi);
446 ksi.ksi_signo = SIGILL;
447 ksi.ksi_trap = type & ~T_USER;
448 ksi.ksi_addr = (void *) frame->tf_rip;
449 switch (type) {
450 case T_PRIVINFLT|T_USER:
451 ksi.ksi_code = ILL_PRVOPC;
452 break;
453 case T_FPOPFLT|T_USER:
454 ksi.ksi_code = ILL_COPROC;
455 break;
456 default:
457 KASSERT(0);
458 break;
459 }
460 goto trapsignal;
461
462 case T_ASTFLT|T_USER:
463 /* Allow process switch. */
464 //curcpu()->ci_data.cpu_nast++;
465 if (l->l_pflag & LP_OWEUPC) {
466 l->l_pflag &= ~LP_OWEUPC;
467 ADDUPROF(l);
468 }
469 /* Allow a forced task switch. */
470 if (curcpu()->ci_want_resched) {
471 preempt();
472 }
473 goto out;
474
475 case T_BOUND|T_USER:
476 case T_OFLOW|T_USER:
477 case T_DIVIDE|T_USER:
478 KSI_INIT_TRAP(&ksi);
479 ksi.ksi_signo = SIGFPE;
480 ksi.ksi_trap = type & ~T_USER;
481 ksi.ksi_addr = (void *)frame->tf_rip;
482 switch (type) {
483 case T_BOUND|T_USER:
484 ksi.ksi_code = FPE_FLTSUB;
485 break;
486 case T_OFLOW|T_USER:
487 ksi.ksi_code = FPE_INTOVF;
488 break;
489 case T_DIVIDE|T_USER:
490 ksi.ksi_code = FPE_INTDIV;
491 break;
492 default:
493#ifdef DIAGNOSTIC
494 panic("unhandled type %x\n", type);
495#endif
496 break;
497 }
498 goto trapsignal;
499
500 case T_PAGEFLT:
501 /* Allow page faults in kernel mode. */
502 if (__predict_false(l == NULL))
503 goto we_re_toast;
504
505 /*
506 * fusuintrfailure is used by [fs]uswintr() to prevent
507 * page faulting from inside the profiling interrupt.
508 */
509 onfault = pcb->pcb_onfault;
510 if (onfault == fusuintrfailure) {
511 goto copyefault;
512 }
513 if (cpu_intr_p() || (l->l_pflag & LP_INTR) != 0) {
514 goto we_re_toast;
515 }
516
517 cr2 = rcr2();
518
519 if (frame->tf_err & PGEX_X) {
520 /* SMEP might have brought us here */
521 if (cr2 > VM_MIN_ADDRESS && cr2 <= VM_MAXUSER_ADDRESS)
522 panic("prevented execution of %p (SMEP)",
523 (void *)cr2);
524 }
525
526 goto faultcommon;
527
528 case T_PAGEFLT|T_USER: { /* page fault */
529 register vaddr_t va;
530 register struct vmspace *vm;
531 register struct vm_map *map;
532 vm_prot_t ftype;
533 extern struct vm_map *kernel_map;
534
535 cr2 = rcr2();
536 if (p->p_emul->e_usertrap != NULL &&
537 (*p->p_emul->e_usertrap)(l, cr2, frame) != 0)
538 return;
539faultcommon:
540 vm = p->p_vmspace;
541 if (__predict_false(vm == NULL)) {
542 goto we_re_toast;
543 }
544 pcb->pcb_cr2 = cr2;
545 va = trunc_page((vaddr_t)cr2);
546 /*
547 * It is only a kernel address space fault iff:
548 * 1. (type & T_USER) == 0 and
549 * 2. pcb_onfault not set or
550 * 3. pcb_onfault set but supervisor space fault
551 * The last can occur during an exec() copyin where the
552 * argument space is lazy-allocated.
553 */
554 if (type == T_PAGEFLT && va >= VM_MIN_KERNEL_ADDRESS)
555 map = kernel_map;
556 else
557 map = &vm->vm_map;
558 if (frame->tf_err & PGEX_W)
559 ftype = VM_PROT_WRITE;
560 else if (frame->tf_err & PGEX_X)
561 ftype = VM_PROT_EXECUTE;
562 else
563 ftype = VM_PROT_READ;
564
565#ifdef DIAGNOSTIC
566 if (map == kernel_map && va == 0) {
567 printf("trap: bad kernel access at %lx\n", va);
568 goto we_re_toast;
569 }
570#endif
571 /* Fault the original page in. */
572 onfault = pcb->pcb_onfault;
573 pcb->pcb_onfault = NULL;
574 error = uvm_fault(map, va, ftype);
575 pcb->pcb_onfault = onfault;
576 if (error == 0) {
577 if (map != kernel_map && (void *)va >= vm->vm_maxsaddr)
578 uvm_grow(p, va);
579
580 pfail = false;
581 while (type == T_PAGEFLT) {
582 /*
583 * we need to switch pmap now if we're in
584 * the middle of copyin/out.
585 *
586 * but we don't need to do so for kcopy as
587 * it never touch userspace.
588 */
589 kpreempt_disable();
590 if (curcpu()->ci_want_pmapload) {
591 onfault = onfault_handler(pcb, frame);
592 if (onfault != kcopy_fault) {
593 pmap_load();
594 }
595 }
596 /*
597 * We need to keep the pmap loaded and
598 * so avoid being preempted until back
599 * into the copy functions. Disable
600 * interrupts at the hardware level before
601 * re-enabling preemption. Interrupts
602 * will be re-enabled by 'iret' when
603 * returning back out of the trap stub.
604 * They'll only be re-enabled when the
605 * program counter is once again in
606 * the copy functions, and so visible
607 * to cpu_kpreempt_exit().
608 */
609#ifndef XEN
610 x86_disable_intr();
611#endif
612 l->l_nopreempt--;
613 if (l->l_nopreempt > 0 || !l->l_dopreempt ||
614 pfail) {
615 return;
616 }
617#ifndef XEN
618 x86_enable_intr();
619#endif
620 /*
621 * If preemption fails for some reason,
622 * don't retry it. The conditions won't
623 * change under our nose.
624 */
625 pfail = kpreempt(0);
626 }
627 goto out;
628 }
629
630 if (type == T_PAGEFLT) {
631 onfault = onfault_handler(pcb, frame);
632 if (onfault != NULL)
633 goto copyfault;
634 printf("uvm_fault(%p, 0x%lx, %d) -> %x\n",
635 map, va, ftype, error);
636 goto kernelfault;
637 }
638
639 KSI_INIT_TRAP(&ksi);
640 ksi.ksi_trap = type & ~T_USER;
641 ksi.ksi_addr = (void *)cr2;
642 switch (error) {
643 case EINVAL:
644 ksi.ksi_signo = SIGBUS;
645 ksi.ksi_code = BUS_ADRERR;
646 break;
647 case EACCES:
648 ksi.ksi_signo = SIGSEGV;
649 ksi.ksi_code = SEGV_ACCERR;
650 error = EFAULT;
651 break;
652 case ENOMEM:
653 ksi.ksi_signo = SIGKILL;
654 printf("UVM: pid %d.%d (%s), uid %d killed: "
655 "out of swap\n", p->p_pid, l->l_lid, p->p_comm,
656 l->l_cred ? kauth_cred_geteuid(l->l_cred) : -1);
657 break;
658 default:
659 ksi.ksi_signo = SIGSEGV;
660 ksi.ksi_code = SEGV_MAPERR;
661 break;
662 }
663
664#ifdef TRAP_SIGDEBUG
665 printf("pid %d.%d (%s): signal %d at rip %#lx addr %#lx "
666 "error %d trap %d cr2 %p\n", p->p_pid, l->l_lid, p->p_comm,
667 ksi.ksi_signo, frame->tf_rip, va, error, ksi.ksi_trap,
668 ksi.ksi_addr);
669 frame_dump(frame);
670#endif
671 (*p->p_emul->e_trapsignal)(l, &ksi);
672 break;
673 }
674
675 case T_TRCTRAP:
676 /* Check whether they single-stepped into a lcall. */
677 if (frame->tf_rip == (uint64_t)IDTVEC(oosyscall) ||
678 frame->tf_rip == (uint64_t)IDTVEC(osyscall) ||
679 frame->tf_rip == (uint64_t)IDTVEC(syscall32)) {
680 frame->tf_rflags &= ~PSL_T;
681 return;
682 }
683 goto we_re_toast;
684
685 case T_BPTFLT|T_USER: /* bpt instruction fault */
686 case T_TRCTRAP|T_USER: /* trace trap */
687 /*
688 * Don't go single-stepping into a RAS.
689 */
690
691 if (p->p_raslist == NULL ||
692 (ras_lookup(p, (void *)frame->tf_rip) == (void *)-1)) {
693 KSI_INIT_TRAP(&ksi);
694 ksi.ksi_signo = SIGTRAP;
695 ksi.ksi_trap = type & ~T_USER;
696 if (type == (T_BPTFLT|T_USER))
697 ksi.ksi_code = TRAP_BRKPT;
698 else
699 ksi.ksi_code = TRAP_TRACE;
700 (*p->p_emul->e_trapsignal)(l, &ksi);
701 }
702 break;
703
704 case T_NMI:
705 if (nmi_dispatch(frame))
706 return;
707 /* NMI can be hooked up to a pushbutton for debugging */
708 if (kgdb_trap(type, frame))
709 return;
710 if (kdb_trap(type, 0, frame))
711 return;
712 /* machine/parity/power fail/"kitchen sink" faults */
713
714 x86_nmi();
715 return;
716 }
717
718 if ((type & T_USER) == 0)
719 return;
720out:
721 userret(l);
722 return;
723trapsignal:
724 (*p->p_emul->e_trapsignal)(l, &ksi);
725 userret(l);
726}
727
728/*
729 * startlwp: start of a new LWP.
730 */
731void
732startlwp(void *arg)
733{
734 ucontext_t *uc = arg;
735 lwp_t *l = curlwp;
736 int error __diagused;
737
738 error = cpu_setmcontext(l, &uc->uc_mcontext, uc->uc_flags);
739 KASSERT(error == 0);
740
741 kmem_free(uc, sizeof(ucontext_t));
742 userret(l);
743}
744
745#ifdef TRAP_SIGDEBUG
746static void
747frame_dump(struct trapframe *tf)
748{
749 int i;
750 unsigned long *p;
751
752 printf("rip %p rsp %p rfl %p\n",
753 (void *)tf->tf_rip, (void *)tf->tf_rsp, (void *)tf->tf_rflags);
754 printf("rdi %p rsi %p rdx %p\n",
755 (void *)tf->tf_rdi, (void *)tf->tf_rsi, (void *)tf->tf_rdx);
756 printf("rcx %p r8 %p r9 %p\n",
757 (void *)tf->tf_rcx, (void *)tf->tf_r8, (void *)tf->tf_r9);
758 printf("r10 %p r11 %p r12 %p\n",
759 (void *)tf->tf_r10, (void *)tf->tf_r11, (void *)tf->tf_r12);
760 printf("r13 %p r14 %p r15 %p\n",
761 (void *)tf->tf_r13, (void *)tf->tf_r14, (void *)tf->tf_r15);
762 printf("rbp %p rbx %p rax %p\n",
763 (void *)tf->tf_rbp, (void *)tf->tf_rbx, (void *)tf->tf_rax);
764 printf("cs %lx ds %lx es %lx fs %lx gs %lx ss %lx\n",
765 tf->tf_cs & 0xffff, tf->tf_ds & 0xffff, tf->tf_es & 0xffff,
766 tf->tf_fs & 0xffff, tf->tf_gs & 0xffff, tf->tf_ss & 0xffff);
767
768 printf("\n");
769 printf("Stack dump:\n");
770 for (i = 0, p = (unsigned long *) tf; i < 20; i ++, p += 4)
771 printf(" 0x%.16lx 0x%.16lx 0x%.16lx 0x%.16lx\n", *p, p[1], p[2], p[3]);
772 printf("\n");
773}
774#endif
775