FreeBSD/Linux Kernel Cross Reference
sys/amd64/amd64/trap.c
1 /*-
2 * Copyright (C) 1994, David Greenman
3 * Copyright (c) 1990, 1993
4 * The Regents of the University of California. All rights reserved.
5 *
6 * This code is derived from software contributed to Berkeley by
7 * the University of Utah, and William Jolitz.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 3. All advertising materials mentioning features or use of this software
18 * must display the following acknowledgement:
19 * This product includes software developed by the University of
20 * California, Berkeley and its contributors.
21 * 4. Neither the name of the University nor the names of its contributors
22 * may be used to endorse or promote products derived from this software
23 * without specific prior written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 * SUCH DAMAGE.
36 *
37 * from: @(#)trap.c 7.4 (Berkeley) 5/13/91
38 */
39
40 #include <sys/cdefs.h>
41 __FBSDID("$FreeBSD: src/sys/amd64/amd64/trap.c,v 1.328 2008/09/08 09:55:51 kib Exp $");
42
43 /*
44 * AMD64 Trap and System call handling
45 */
46
47 #include "opt_clock.h"
48 #include "opt_cpu.h"
49 #include "opt_hwpmc_hooks.h"
50 #include "opt_isa.h"
51 #include "opt_kdb.h"
52 #include "opt_kdtrace.h"
53 #include "opt_ktrace.h"
54
55 #include <sys/param.h>
56 #include <sys/bus.h>
57 #include <sys/systm.h>
58 #include <sys/proc.h>
59 #include <sys/pioctl.h>
60 #include <sys/ptrace.h>
61 #include <sys/kdb.h>
62 #include <sys/kernel.h>
63 #include <sys/ktr.h>
64 #include <sys/lock.h>
65 #include <sys/mutex.h>
66 #include <sys/resourcevar.h>
67 #include <sys/signalvar.h>
68 #include <sys/syscall.h>
69 #include <sys/sysctl.h>
70 #include <sys/sysent.h>
71 #include <sys/uio.h>
72 #include <sys/vmmeter.h>
73 #ifdef KTRACE
74 #include <sys/ktrace.h>
75 #endif
76 #ifdef HWPMC_HOOKS
77 #include <sys/pmckern.h>
78 #endif
79 #include <security/audit/audit.h>
80
81 #include <vm/vm.h>
82 #include <vm/vm_param.h>
83 #include <vm/pmap.h>
84 #include <vm/vm_kern.h>
85 #include <vm/vm_map.h>
86 #include <vm/vm_page.h>
87 #include <vm/vm_extern.h>
88
89 #include <machine/cpu.h>
90 #include <machine/intr_machdep.h>
91 #include <machine/md_var.h>
92 #include <machine/pcb.h>
93 #ifdef SMP
94 #include <machine/smp.h>
95 #endif
96 #include <machine/tss.h>
97
98 #ifdef KDTRACE_HOOKS
99 #include <sys/dtrace_bsd.h>
100
101 /*
102 * This is a hook which is initialised by the dtrace module
103 * to handle traps which might occur during DTrace probe
104 * execution.
105 */
106 dtrace_trap_func_t dtrace_trap_func;
107
108 dtrace_doubletrap_func_t dtrace_doubletrap_func;
109
110 /*
111 * This is a hook which is initialised by the systrace module
112 * when it is loaded. This keeps the DTrace syscall provider
113 * implementation opaque.
114 */
115 systrace_probe_func_t systrace_probe_func;
116 #endif
117
118 extern void trap(struct trapframe *frame);
119 extern void syscall(struct trapframe *frame);
120 void dblfault_handler(struct trapframe *frame);
121
122 static int trap_pfault(struct trapframe *, int);
123 static void trap_fatal(struct trapframe *, vm_offset_t);
124
125 #define MAX_TRAP_MSG 30
126 static char *trap_msg[] = {
127 "", /* 0 unused */
128 "privileged instruction fault", /* 1 T_PRIVINFLT */
129 "", /* 2 unused */
130 "breakpoint instruction fault", /* 3 T_BPTFLT */
131 "", /* 4 unused */
132 "", /* 5 unused */
133 "arithmetic trap", /* 6 T_ARITHTRAP */
134 "", /* 7 unused */
135 "", /* 8 unused */
136 "general protection fault", /* 9 T_PROTFLT */
137 "trace trap", /* 10 T_TRCTRAP */
138 "", /* 11 unused */
139 "page fault", /* 12 T_PAGEFLT */
140 "", /* 13 unused */
141 "alignment fault", /* 14 T_ALIGNFLT */
142 "", /* 15 unused */
143 "", /* 16 unused */
144 "", /* 17 unused */
145 "integer divide fault", /* 18 T_DIVIDE */
146 "non-maskable interrupt trap", /* 19 T_NMI */
147 "overflow trap", /* 20 T_OFLOW */
148 "FPU bounds check fault", /* 21 T_BOUND */
149 "FPU device not available", /* 22 T_DNA */
150 "double fault", /* 23 T_DOUBLEFLT */
151 "FPU operand fetch fault", /* 24 T_FPOPFLT */
152 "invalid TSS fault", /* 25 T_TSSFLT */
153 "segment not present fault", /* 26 T_SEGNPFLT */
154 "stack fault", /* 27 T_STKFLT */
155 "machine check trap", /* 28 T_MCHK */
156 "SIMD floating-point exception", /* 29 T_XMMFLT */
157 "reserved (unknown) fault", /* 30 T_RESERVED */
158 };
159
160 #ifdef KDB
161 static int kdb_on_nmi = 1;
162 SYSCTL_INT(_machdep, OID_AUTO, kdb_on_nmi, CTLFLAG_RW,
163 &kdb_on_nmi, 0, "Go to KDB on NMI");
164 #endif
165 static int panic_on_nmi = 1;
166 SYSCTL_INT(_machdep, OID_AUTO, panic_on_nmi, CTLFLAG_RW,
167 &panic_on_nmi, 0, "Panic on NMI");
168 static int prot_fault_translation = 0;
169 SYSCTL_INT(_machdep, OID_AUTO, prot_fault_translation, CTLFLAG_RW,
170 &prot_fault_translation, 0, "Select signal to deliver on protection fault");
171
172 extern char *syscallnames[];
173
174 /*
175 * Exception, fault, and trap interface to the FreeBSD kernel.
176 * This common code is called from assembly language IDT gate entry
177 * routines that prepare a suitable stack frame, and restore this
178 * frame after the exception has been processed.
179 */
180
181 void
182 trap(struct trapframe *frame)
183 {
184 struct thread *td = curthread;
185 struct proc *p = td->td_proc;
186 int i = 0, ucode = 0, code;
187 u_int type;
188 register_t addr = 0;
189 ksiginfo_t ksi;
190
191 PCPU_INC(cnt.v_trap);
192 type = frame->tf_trapno;
193
194 #ifdef SMP
195 #ifdef STOP_NMI
196 /* Handler for NMI IPIs used for stopping CPUs. */
197 if (type == T_NMI) {
198 if (ipi_nmi_handler() == 0)
199 goto out;
200 }
201 #endif /* STOP_NMI */
202 #endif /* SMP */
203
204 #ifdef KDB
205 if (kdb_active) {
206 kdb_reenter();
207 goto out;
208 }
209 #endif
210
211 #ifdef HWPMC_HOOKS
212 /*
213 * CPU PMCs interrupt using an NMI. If the PMC module is
214 * active, pass the 'rip' value to the PMC module's interrupt
215 * handler. A return value of '1' from the handler means that
216 * the NMI was handled by it and we can return immediately.
217 */
218 if (type == T_NMI && pmc_intr &&
219 (*pmc_intr)(PCPU_GET(cpuid), frame))
220 goto out;
221 #endif
222
223 #ifdef KDTRACE_HOOKS
224 /*
225 * A trap can occur while DTrace executes a probe. Before
226 * executing the probe, DTrace blocks re-scheduling and sets
227 * a flag in it's per-cpu flags to indicate that it doesn't
228 * want to fault. On returning from the the probe, the no-fault
229 * flag is cleared and finally re-scheduling is enabled.
230 *
231 * If the DTrace kernel module has registered a trap handler,
232 * call it and if it returns non-zero, assume that it has
233 * handled the trap and modified the trap frame so that this
234 * function can return normally.
235 */
236 if (dtrace_trap_func != NULL)
237 if ((*dtrace_trap_func)(frame, type))
238 goto out;
239 #endif
240
241 if ((frame->tf_rflags & PSL_I) == 0) {
242 /*
243 * Buggy application or kernel code has disabled
244 * interrupts and then trapped. Enabling interrupts
245 * now is wrong, but it is better than running with
246 * interrupts disabled until they are accidentally
247 * enabled later.
248 */
249 if (ISPL(frame->tf_cs) == SEL_UPL)
250 printf(
251 "pid %ld (%s): trap %d with interrupts disabled\n",
252 (long)curproc->p_pid, curthread->td_name, type);
253 else if (type != T_NMI && type != T_BPTFLT &&
254 type != T_TRCTRAP) {
255 /*
256 * XXX not quite right, since this may be for a
257 * multiple fault in user mode.
258 */
259 printf("kernel trap %d with interrupts disabled\n",
260 type);
261 /*
262 * We shouldn't enable interrupts while holding a
263 * spin lock or servicing an NMI.
264 */
265 if (type != T_NMI && td->td_md.md_spinlock_count == 0)
266 enable_intr();
267 }
268 }
269
270 code = frame->tf_err;
271 if (type == T_PAGEFLT) {
272 /*
273 * If we get a page fault while in a critical section, then
274 * it is most likely a fatal kernel page fault. The kernel
275 * is already going to panic trying to get a sleep lock to
276 * do the VM lookup, so just consider it a fatal trap so the
277 * kernel can print out a useful trap message and even get
278 * to the debugger.
279 *
280 * If we get a page fault while holding a non-sleepable
281 * lock, then it is most likely a fatal kernel page fault.
282 * If WITNESS is enabled, then it's going to whine about
283 * bogus LORs with various VM locks, so just skip to the
284 * fatal trap handling directly.
285 */
286 if (td->td_critnest != 0 ||
287 WITNESS_CHECK(WARN_SLEEPOK | WARN_GIANTOK, NULL,
288 "Kernel page fault") != 0)
289 trap_fatal(frame, frame->tf_addr);
290 }
291
292 if (ISPL(frame->tf_cs) == SEL_UPL) {
293 /* user trap */
294
295 td->td_pticks = 0;
296 td->td_frame = frame;
297 addr = frame->tf_rip;
298 if (td->td_ucred != p->p_ucred)
299 cred_update_thread(td);
300
301 switch (type) {
302 case T_PRIVINFLT: /* privileged instruction fault */
303 i = SIGILL;
304 ucode = ILL_PRVOPC;
305 break;
306
307 case T_BPTFLT: /* bpt instruction fault */
308 case T_TRCTRAP: /* trace trap */
309 enable_intr();
310 frame->tf_rflags &= ~PSL_T;
311 i = SIGTRAP;
312 ucode = (type == T_TRCTRAP ? TRAP_TRACE : TRAP_BRKPT);
313 break;
314
315 case T_ARITHTRAP: /* arithmetic trap */
316 ucode = fputrap();
317 if (ucode == -1)
318 goto userout;
319 i = SIGFPE;
320 break;
321
322 case T_PROTFLT: /* general protection fault */
323 i = SIGBUS;
324 ucode = BUS_OBJERR;
325 break;
326 case T_STKFLT: /* stack fault */
327 case T_SEGNPFLT: /* segment not present fault */
328 i = SIGBUS;
329 ucode = BUS_ADRERR;
330 break;
331 case T_TSSFLT: /* invalid TSS fault */
332 i = SIGBUS;
333 ucode = BUS_OBJERR;
334 break;
335 case T_DOUBLEFLT: /* double fault */
336 default:
337 i = SIGBUS;
338 ucode = BUS_OBJERR;
339 break;
340
341 case T_PAGEFLT: /* page fault */
342 addr = frame->tf_addr;
343 i = trap_pfault(frame, TRUE);
344 if (i == -1)
345 goto userout;
346 if (i == 0)
347 goto user;
348
349 if (i == SIGSEGV)
350 ucode = SEGV_MAPERR;
351 else {
352 if (prot_fault_translation == 0) {
353 /*
354 * Autodetect.
355 * This check also covers the images
356 * without the ABI-tag ELF note.
357 */
358 if (p->p_osrel >= 700004) {
359 i = SIGSEGV;
360 ucode = SEGV_ACCERR;
361 } else {
362 i = SIGBUS;
363 ucode = BUS_PAGE_FAULT;
364 }
365 } else if (prot_fault_translation == 1) {
366 /*
367 * Always compat mode.
368 */
369 i = SIGBUS;
370 ucode = BUS_PAGE_FAULT;
371 } else {
372 /*
373 * Always SIGSEGV mode.
374 */
375 i = SIGSEGV;
376 ucode = SEGV_ACCERR;
377 }
378 }
379 break;
380
381 case T_DIVIDE: /* integer divide fault */
382 ucode = FPE_INTDIV;
383 i = SIGFPE;
384 break;
385
386 #ifdef DEV_ISA
387 case T_NMI:
388 /* machine/parity/power fail/"kitchen sink" faults */
389 /* XXX Giant */
390 if (isa_nmi(code) == 0) {
391 #ifdef KDB
392 /*
393 * NMI can be hooked up to a pushbutton
394 * for debugging.
395 */
396 if (kdb_on_nmi) {
397 printf ("NMI ... going to debugger\n");
398 kdb_trap(type, 0, frame);
399 }
400 #endif /* KDB */
401 goto userout;
402 } else if (panic_on_nmi)
403 panic("NMI indicates hardware failure");
404 break;
405 #endif /* DEV_ISA */
406
407 case T_OFLOW: /* integer overflow fault */
408 ucode = FPE_INTOVF;
409 i = SIGFPE;
410 break;
411
412 case T_BOUND: /* bounds check fault */
413 ucode = FPE_FLTSUB;
414 i = SIGFPE;
415 break;
416
417 case T_DNA:
418 /* transparent fault (due to context switch "late") */
419 if (fpudna())
420 goto userout;
421 printf("pid %d killed due to lack of floating point\n",
422 p->p_pid);
423 i = SIGKILL;
424 ucode = 0;
425 break;
426
427 case T_FPOPFLT: /* FPU operand fetch fault */
428 ucode = ILL_COPROC;
429 i = SIGILL;
430 break;
431
432 case T_XMMFLT: /* SIMD floating-point exception */
433 ucode = 0; /* XXX */
434 i = SIGFPE;
435 break;
436 }
437 } else {
438 /* kernel trap */
439
440 KASSERT(cold || td->td_ucred != NULL,
441 ("kernel trap doesn't have ucred"));
442 switch (type) {
443 case T_PAGEFLT: /* page fault */
444 (void) trap_pfault(frame, FALSE);
445 goto out;
446
447 case T_DNA:
448 /*
449 * The kernel is apparently using fpu for copying.
450 * XXX this should be fatal unless the kernel has
451 * registered such use.
452 */
453 if (fpudna()) {
454 printf("fpudna in kernel mode!\n");
455 goto out;
456 }
457 break;
458
459 case T_STKFLT: /* stack fault */
460 break;
461
462 case T_PROTFLT: /* general protection fault */
463 case T_SEGNPFLT: /* segment not present fault */
464 if (td->td_intr_nesting_level != 0)
465 break;
466
467 /*
468 * Invalid segment selectors and out of bounds
469 * %rip's and %rsp's can be set up in user mode.
470 * This causes a fault in kernel mode when the
471 * kernel tries to return to user mode. We want
472 * to get this fault so that we can fix the
473 * problem here and not have to check all the
474 * selectors and pointers when the user changes
475 * them.
476 */
477 if (frame->tf_rip == (long)doreti_iret) {
478 frame->tf_rip = (long)doreti_iret_fault;
479 goto out;
480 }
481 if (PCPU_GET(curpcb)->pcb_onfault != NULL) {
482 frame->tf_rip =
483 (long)PCPU_GET(curpcb)->pcb_onfault;
484 goto out;
485 }
486 break;
487
488 case T_TSSFLT:
489 /*
490 * PSL_NT can be set in user mode and isn't cleared
491 * automatically when the kernel is entered. This
492 * causes a TSS fault when the kernel attempts to
493 * `iret' because the TSS link is uninitialized. We
494 * want to get this fault so that we can fix the
495 * problem here and not every time the kernel is
496 * entered.
497 */
498 if (frame->tf_rflags & PSL_NT) {
499 frame->tf_rflags &= ~PSL_NT;
500 goto out;
501 }
502 break;
503
504 case T_TRCTRAP: /* trace trap */
505 /*
506 * Ignore debug register trace traps due to
507 * accesses in the user's address space, which
508 * can happen under several conditions such as
509 * if a user sets a watchpoint on a buffer and
510 * then passes that buffer to a system call.
511 * We still want to get TRCTRAPS for addresses
512 * in kernel space because that is useful when
513 * debugging the kernel.
514 */
515 if (user_dbreg_trap()) {
516 /*
517 * Reset breakpoint bits because the
518 * processor doesn't
519 */
520 /* XXX check upper bits here */
521 load_dr6(rdr6() & 0xfffffff0);
522 goto out;
523 }
524 /*
525 * FALLTHROUGH (TRCTRAP kernel mode, kernel address)
526 */
527 case T_BPTFLT:
528 /*
529 * If KDB is enabled, let it handle the debugger trap.
530 * Otherwise, debugger traps "can't happen".
531 */
532 #ifdef KDB
533 if (kdb_trap(type, 0, frame))
534 goto out;
535 #endif
536 break;
537
538 #ifdef DEV_ISA
539 case T_NMI:
540 /* XXX Giant */
541 /* machine/parity/power fail/"kitchen sink" faults */
542 if (isa_nmi(code) == 0) {
543 #ifdef KDB
544 /*
545 * NMI can be hooked up to a pushbutton
546 * for debugging.
547 */
548 if (kdb_on_nmi) {
549 printf ("NMI ... going to debugger\n");
550 kdb_trap(type, 0, frame);
551 }
552 #endif /* KDB */
553 goto out;
554 } else if (panic_on_nmi == 0)
555 goto out;
556 /* FALLTHROUGH */
557 #endif /* DEV_ISA */
558 }
559
560 trap_fatal(frame, 0);
561 goto out;
562 }
563
564 /* Translate fault for emulators (e.g. Linux) */
565 if (*p->p_sysent->sv_transtrap)
566 i = (*p->p_sysent->sv_transtrap)(i, type);
567
568 ksiginfo_init_trap(&ksi);
569 ksi.ksi_signo = i;
570 ksi.ksi_code = ucode;
571 ksi.ksi_trapno = type;
572 ksi.ksi_addr = (void *)addr;
573 trapsignal(td, &ksi);
574
575 #ifdef DEBUG
576 if (type <= MAX_TRAP_MSG) {
577 uprintf("fatal process exception: %s",
578 trap_msg[type]);
579 if ((type == T_PAGEFLT) || (type == T_PROTFLT))
580 uprintf(", fault VA = 0x%lx", frame->tf_addr);
581 uprintf("\n");
582 }
583 #endif
584
585 user:
586 userret(td, frame);
587 mtx_assert(&Giant, MA_NOTOWNED);
588 userout:
589 out:
590 return;
591 }
592
593 static int
594 trap_pfault(frame, usermode)
595 struct trapframe *frame;
596 int usermode;
597 {
598 vm_offset_t va;
599 struct vmspace *vm = NULL;
600 vm_map_t map;
601 int rv = 0;
602 vm_prot_t ftype;
603 struct thread *td = curthread;
604 struct proc *p = td->td_proc;
605 vm_offset_t eva = frame->tf_addr;
606
607 va = trunc_page(eva);
608 if (va >= VM_MIN_KERNEL_ADDRESS) {
609 /*
610 * Don't allow user-mode faults in kernel address space.
611 */
612 if (usermode)
613 goto nogo;
614
615 map = kernel_map;
616 } else {
617 /*
618 * This is a fault on non-kernel virtual memory.
619 * vm is initialized above to NULL. If curproc is NULL
620 * or curproc->p_vmspace is NULL the fault is fatal.
621 */
622 if (p != NULL)
623 vm = p->p_vmspace;
624
625 if (vm == NULL)
626 goto nogo;
627
628 map = &vm->vm_map;
629 }
630
631 /*
632 * PGEX_I is defined only if the execute disable bit capability is
633 * supported and enabled.
634 */
635 if (frame->tf_err & PGEX_W)
636 ftype = VM_PROT_WRITE;
637 else if ((frame->tf_err & PGEX_I) && pg_nx != 0)
638 ftype = VM_PROT_EXECUTE;
639 else
640 ftype = VM_PROT_READ;
641
642 if (map != kernel_map) {
643 /*
644 * Keep swapout from messing with us during this
645 * critical time.
646 */
647 PROC_LOCK(p);
648 ++p->p_lock;
649 PROC_UNLOCK(p);
650
651 /* Fault in the user page: */
652 rv = vm_fault(map, va, ftype,
653 (ftype & VM_PROT_WRITE) ? VM_FAULT_DIRTY
654 : VM_FAULT_NORMAL);
655
656 PROC_LOCK(p);
657 --p->p_lock;
658 PROC_UNLOCK(p);
659 } else {
660 /*
661 * Don't have to worry about process locking or stacks in the
662 * kernel.
663 */
664 rv = vm_fault(map, va, ftype, VM_FAULT_NORMAL);
665 }
666 if (rv == KERN_SUCCESS)
667 return (0);
668 nogo:
669 if (!usermode) {
670 if (td->td_intr_nesting_level == 0 &&
671 PCPU_GET(curpcb)->pcb_onfault != NULL) {
672 frame->tf_rip = (long)PCPU_GET(curpcb)->pcb_onfault;
673 return (0);
674 }
675 trap_fatal(frame, eva);
676 return (-1);
677 }
678
679 return((rv == KERN_PROTECTION_FAILURE) ? SIGBUS : SIGSEGV);
680 }
681
682 static void
683 trap_fatal(frame, eva)
684 struct trapframe *frame;
685 vm_offset_t eva;
686 {
687 int code, ss;
688 u_int type;
689 long esp;
690 struct soft_segment_descriptor softseg;
691 char *msg;
692
693 code = frame->tf_err;
694 type = frame->tf_trapno;
695 sdtossd(&gdt[NGDT * PCPU_GET(cpuid) + IDXSEL(frame->tf_cs & 0xffff)],
696 &softseg);
697
698 if (type <= MAX_TRAP_MSG)
699 msg = trap_msg[type];
700 else
701 msg = "UNKNOWN";
702 printf("\n\nFatal trap %d: %s while in %s mode\n", type, msg,
703 ISPL(frame->tf_cs) == SEL_UPL ? "user" : "kernel");
704 #ifdef SMP
705 /* two separate prints in case of a trap on an unmapped page */
706 printf("cpuid = %d; ", PCPU_GET(cpuid));
707 printf("apic id = %02x\n", PCPU_GET(apic_id));
708 #endif
709 if (type == T_PAGEFLT) {
710 printf("fault virtual address = 0x%lx\n", eva);
711 printf("fault code = %s %s %s, %s\n",
712 code & PGEX_U ? "user" : "supervisor",
713 code & PGEX_W ? "write" : "read",
714 code & PGEX_I ? "instruction" : "data",
715 code & PGEX_P ? "protection violation" : "page not present");
716 }
717 printf("instruction pointer = 0x%lx:0x%lx\n",
718 frame->tf_cs & 0xffff, frame->tf_rip);
719 if (ISPL(frame->tf_cs) == SEL_UPL) {
720 ss = frame->tf_ss & 0xffff;
721 esp = frame->tf_rsp;
722 } else {
723 ss = GSEL(GDATA_SEL, SEL_KPL);
724 esp = (long)&frame->tf_rsp;
725 }
726 printf("stack pointer = 0x%x:0x%lx\n", ss, esp);
727 printf("frame pointer = 0x%x:0x%lx\n", ss, frame->tf_rbp);
728 printf("code segment = base 0x%lx, limit 0x%lx, type 0x%x\n",
729 softseg.ssd_base, softseg.ssd_limit, softseg.ssd_type);
730 printf(" = DPL %d, pres %d, long %d, def32 %d, gran %d\n",
731 softseg.ssd_dpl, softseg.ssd_p, softseg.ssd_long, softseg.ssd_def32,
732 softseg.ssd_gran);
733 printf("processor eflags = ");
734 if (frame->tf_rflags & PSL_T)
735 printf("trace trap, ");
736 if (frame->tf_rflags & PSL_I)
737 printf("interrupt enabled, ");
738 if (frame->tf_rflags & PSL_NT)
739 printf("nested task, ");
740 if (frame->tf_rflags & PSL_RF)
741 printf("resume, ");
742 printf("IOPL = %ld\n", (frame->tf_rflags & PSL_IOPL) >> 12);
743 printf("current process = ");
744 if (curproc) {
745 printf("%lu (%s)\n",
746 (u_long)curproc->p_pid, curthread->td_name ?
747 curthread->td_name : "");
748 } else {
749 printf("Idle\n");
750 }
751
752 #ifdef KDB
753 if (debugger_on_panic || kdb_active)
754 if (kdb_trap(type, 0, frame))
755 return;
756 #endif
757 printf("trap number = %d\n", type);
758 if (type <= MAX_TRAP_MSG)
759 panic("%s", trap_msg[type]);
760 else
761 panic("unknown/reserved trap");
762 }
763
764 /*
765 * Double fault handler. Called when a fault occurs while writing
766 * a frame for a trap/exception onto the stack. This usually occurs
767 * when the stack overflows (such is the case with infinite recursion,
768 * for example).
769 */
770 void
771 dblfault_handler(struct trapframe *frame)
772 {
773 #ifdef KDTRACE_HOOKS
774 if (dtrace_doubletrap_func != NULL)
775 (*dtrace_doubletrap_func)();
776 #endif
777 printf("\nFatal double fault\n");
778 printf("rip = 0x%lx\n", frame->tf_rip);
779 printf("rsp = 0x%lx\n", frame->tf_rsp);
780 printf("rbp = 0x%lx\n", frame->tf_rbp);
781 #ifdef SMP
782 /* two separate prints in case of a trap on an unmapped page */
783 printf("cpuid = %d; ", PCPU_GET(cpuid));
784 printf("apic id = %02x\n", PCPU_GET(apic_id));
785 #endif
786 panic("double fault");
787 }
788
789 /*
790 * syscall - system call request C handler
791 *
792 * A system call is essentially treated as a trap.
793 */
794 void
795 syscall(struct trapframe *frame)
796 {
797 caddr_t params;
798 struct sysent *callp;
799 struct thread *td = curthread;
800 struct proc *p = td->td_proc;
801 register_t orig_tf_rflags;
802 int error;
803 int narg;
804 register_t args[8];
805 register_t *argp;
806 u_int code;
807 int reg, regcnt;
808 ksiginfo_t ksi;
809
810 PCPU_INC(cnt.v_syscall);
811
812 #ifdef DIAGNOSTIC
813 if (ISPL(frame->tf_cs) != SEL_UPL) {
814 panic("syscall");
815 /* NOT REACHED */
816 }
817 #endif
818
819 reg = 0;
820 regcnt = 6;
821 td->td_pticks = 0;
822 td->td_frame = frame;
823 if (td->td_ucred != p->p_ucred)
824 cred_update_thread(td);
825 params = (caddr_t)frame->tf_rsp + sizeof(register_t);
826 code = frame->tf_rax;
827 orig_tf_rflags = frame->tf_rflags;
828
829 if (p->p_sysent->sv_prepsyscall) {
830 /*
831 * The prep code is MP aware.
832 */
833 (*p->p_sysent->sv_prepsyscall)(frame, (int *)args, &code, ¶ms);
834 } else {
835 if (code == SYS_syscall || code == SYS___syscall) {
836 code = frame->tf_rdi;
837 reg++;
838 regcnt--;
839 }
840 }
841
842 if (p->p_sysent->sv_mask)
843 code &= p->p_sysent->sv_mask;
844
845 if (code >= p->p_sysent->sv_size)
846 callp = &p->p_sysent->sv_table[0];
847 else
848 callp = &p->p_sysent->sv_table[code];
849
850 narg = callp->sy_narg;
851
852 /*
853 * copyin and the ktrsyscall()/ktrsysret() code is MP-aware
854 */
855 KASSERT(narg <= sizeof(args) / sizeof(args[0]),
856 ("Too many syscall arguments!"));
857 error = 0;
858 argp = &frame->tf_rdi;
859 argp += reg;
860 bcopy(argp, args, sizeof(args[0]) * regcnt);
861 if (narg > regcnt) {
862 KASSERT(params != NULL, ("copyin args with no params!"));
863 error = copyin(params, &args[regcnt],
864 (narg - regcnt) * sizeof(args[0]));
865 }
866 argp = &args[0];
867
868 #ifdef KTRACE
869 if (KTRPOINT(td, KTR_SYSCALL))
870 ktrsyscall(code, narg, argp);
871 #endif
872
873 CTR4(KTR_SYSC, "syscall enter thread %p pid %d proc %s code %d", td,
874 td->td_proc->p_pid, td->td_name, code);
875
876 td->td_syscalls++;
877
878 if (error == 0) {
879 td->td_retval[0] = 0;
880 td->td_retval[1] = frame->tf_rdx;
881
882 STOPEVENT(p, S_SCE, narg);
883
884 PTRACESTOP_SC(p, td, S_PT_SCE);
885
886 #ifdef KDTRACE_HOOKS
887 /*
888 * If the systrace module has registered it's probe
889 * callback and if there is a probe active for the
890 * syscall 'entry', process the probe.
891 */
892 if (systrace_probe_func != NULL && callp->sy_entry != 0)
893 (*systrace_probe_func)(callp->sy_entry, code, callp,
894 args);
895 #endif
896
897 AUDIT_SYSCALL_ENTER(code, td);
898 error = (*callp->sy_call)(td, argp);
899 AUDIT_SYSCALL_EXIT(error, td);
900
901 /* Save the latest error return value. */
902 td->td_errno = error;
903
904 #ifdef KDTRACE_HOOKS
905 /*
906 * If the systrace module has registered it's probe
907 * callback and if there is a probe active for the
908 * syscall 'return', process the probe.
909 */
910 if (systrace_probe_func != NULL && callp->sy_return != 0)
911 (*systrace_probe_func)(callp->sy_return, code, callp,
912 args);
913 #endif
914 |