1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
|
/* $OpenBSD: trap.c,v 1.30 2012/10/09 04:40:36 jsg Exp $ */
/* $NetBSD: trap.c,v 1.2 2003/05/04 23:51:56 fvdl Exp $ */
/*-
* Copyright (c) 1998, 2000 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Charles M. Hannum.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
/*-
* Copyright (c) 1990 The Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* the University of Utah, and William Jolitz.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)trap.c 7.4 (Berkeley) 5/13/91
*/
/*
* amd64 Trap and System call handling
*/
#undef TRAP_SIGDEBUG
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/signalvar.h>
#include <sys/user.h>
#include <sys/acct.h>
#include <sys/kernel.h>
#include <sys/signal.h>
#include <sys/syscall.h>
#include <sys/syscall_mi.h>
#include <uvm/uvm_extern.h>
#include <machine/cpu.h>
#include <machine/cpufunc.h>
#include <machine/fpu.h>
#include <machine/psl.h>
#include <machine/reg.h>
#include <machine/trap.h>
#ifdef DDB
#include <machine/db_machdep.h>
#endif
#include "isa.h"
#ifdef KGDB
#include <sys/kgdb.h>
#endif
void trap(struct trapframe *);
void syscall(struct trapframe *);
const char *trap_type[] = {
"privileged instruction fault", /* 0 T_PRIVINFLT */
"breakpoint trap", /* 1 T_BPTFLT */
"arithmetic trap", /* 2 T_ARITHTRAP */
"asynchronous system trap", /* 3 T_ASTFLT */
"protection fault", /* 4 T_PROTFLT */
"trace trap", /* 5 T_TRCTRAP */
"page fault", /* 6 T_PAGEFLT */
"alignment fault", /* 7 T_ALIGNFLT */
"integer divide fault", /* 8 T_DIVIDE */
"non-maskable interrupt", /* 9 T_NMI */
"overflow trap", /* 10 T_OFLOW */
"bounds check fault", /* 11 T_BOUND */
"FPU not available fault", /* 12 T_DNA */
"double fault", /* 13 T_DOUBLEFLT */
"FPU operand fetch fault", /* 14 T_FPOPFLT */
"invalid TSS fault", /* 15 T_TSSFLT */
"segment not present fault", /* 16 T_SEGNPFLT */
"stack fault", /* 17 T_STKFLT */
"machine check", /* 18 T_MCA */
"SSE FP exception", /* 19 T_XMM */
"reserved trap", /* 20 T_RESERVED */
};
int trap_types = sizeof trap_type / sizeof trap_type[0];
#ifdef DEBUG
int trapdebug = 0;
#endif
#define IDTVEC(name) __CONCAT(X, name)
#ifdef TRAP_SIGDEBUG
static void frame_dump(struct trapframe *);
#endif
/*
* trap(frame):
* Exception, fault, and trap interface to BSD kernel. This
* common code is called from assembly language IDT gate entry
* routines that prepare a suitable stack frame, and restore this
* frame after the exception has been processed.
*/
/*ARGSUSED*/
void
trap(struct trapframe *frame)
{
struct proc *p = curproc;
int type = (int)frame->tf_trapno;
struct pcb *pcb;
extern char doreti_iret[], resume_iret[];
caddr_t onfault;
int error;
uint64_t cr2;
union sigval sv;
uvmexp.traps++;
pcb = (p != NULL && p->p_addr != NULL) ? &p->p_addr->u_pcb : NULL;
#ifdef DEBUG
if (trapdebug) {
printf("trap %d code %lx rip %lx cs %lx rflags %lx cr2 %lx "
"cpl %x\n",
type, frame->tf_err, frame->tf_rip, frame->tf_cs,
frame->tf_rflags, rcr2(), curcpu()->ci_ilevel);
printf("curproc %p\n", curproc);
if (curproc)
printf("pid %d\n", p->p_pid);
}
#endif
if (!KERNELMODE(frame->tf_cs, frame->tf_rflags)) {
type |= T_USER;
p->p_md.md_regs = frame;
}
switch (type) {
default:
we_re_toast:
#ifdef KGDB
if (kgdb_trap(type, frame))
return;
else {
/*
* If this is a breakpoint, don't panic
* if we're not connected.
*/
if (type == T_BPTFLT) {
printf("kgdb: ignored %s\n", trap_type[type]);
return;
}
}
#endif
#ifdef DDB
if (kdb_trap(type, 0, frame))
return;
#endif
if (frame->tf_trapno < trap_types)
printf("fatal %s", trap_type[frame->tf_trapno]);
else
printf("unknown trap %ld", (u_long)frame->tf_trapno);
printf(" in %s mode\n", (type & T_USER) ? "user" : "supervisor");
printf("trap type %d code %lx rip %lx cs %lx rflags %lx cr2 "
" %lx cpl %x rsp %lx\n",
type, frame->tf_err, (u_long)frame->tf_rip, frame->tf_cs,
frame->tf_rflags, rcr2(), curcpu()->ci_ilevel, frame->tf_rsp);
panic("trap type %d, code=%lx, pc=%lx",
type, frame->tf_err, frame->tf_rip);
/*NOTREACHED*/
case T_PROTFLT:
case T_SEGNPFLT:
case T_ALIGNFLT:
case T_TSSFLT:
if (p == NULL)
goto we_re_toast;
/* Check for copyin/copyout fault. */
if (pcb->pcb_onfault != 0) {
error = EFAULT;
copyfault:
frame->tf_rip = (u_int64_t)pcb->pcb_onfault;
frame->tf_rax = error;
return;
}
/*
* Check for failure during return to user mode.
* We do this by looking at the address of the
* instruction that faulted.
*/
if (frame->tf_rip == (u_int64_t)doreti_iret) {
frame->tf_rip = (u_int64_t)resume_iret;
return;
}
goto we_re_toast;
case T_PROTFLT|T_USER: /* protection fault */
case T_TSSFLT|T_USER:
case T_SEGNPFLT|T_USER:
case T_STKFLT|T_USER:
case T_NMI|T_USER:
#ifdef TRAP_SIGDEBUG
printf("pid %d (%s): BUS at rip %lx addr %lx\n",
p->p_pid, p->p_comm, frame->tf_rip, rcr2());
frame_dump(frame);
#endif
sv.sival_ptr = (void *)frame->tf_rip;
KERNEL_LOCK();
trapsignal(p, SIGBUS, type & ~T_USER, BUS_OBJERR, sv);
KERNEL_UNLOCK();
goto out;
case T_ALIGNFLT|T_USER:
sv.sival_ptr = (void *)frame->tf_rip;
KERNEL_LOCK();
trapsignal(p, SIGBUS, type & ~T_USER, BUS_ADRALN, sv);
KERNEL_UNLOCK();
goto out;
case T_PRIVINFLT|T_USER: /* privileged instruction fault */
sv.sival_ptr = (void *)frame->tf_rip;
KERNEL_LOCK();
trapsignal(p, SIGILL, type & ~T_USER, ILL_PRVOPC, sv);
KERNEL_UNLOCK();
goto out;
case T_FPOPFLT|T_USER: /* coprocessor operand fault */
#ifdef TRAP_SIGDEBUG
printf("pid %d (%s): ILL at rip %lx addr %lx\n",
p->p_pid, p->p_comm, frame->tf_rip, rcr2());
frame_dump(frame);
#endif
sv.sival_ptr = (void *)frame->tf_rip;
KERNEL_LOCK();
trapsignal(p, SIGILL, type & ~T_USER, ILL_COPROC, sv);
KERNEL_UNLOCK();
goto out;
case T_ASTFLT|T_USER: /* Allow process switch */
uvmexp.softs++;
if (p->p_flag & P_OWEUPC) {
KERNEL_LOCK();
ADDUPROF(p);
KERNEL_UNLOCK();
}
/* Allow a forced task switch. */
if (curcpu()->ci_want_resched)
preempt(NULL);
goto out;
case T_BOUND|T_USER:
sv.sival_ptr = (void *)frame->tf_rip;
KERNEL_LOCK();
trapsignal(p, SIGFPE, type &~ T_USER, FPE_FLTSUB, sv);
KERNEL_UNLOCK();
goto out;
case T_OFLOW|T_USER:
sv.sival_ptr = (void *)frame->tf_rip;
KERNEL_LOCK();
trapsignal(p, SIGFPE, type &~ T_USER, FPE_INTOVF, sv);
KERNEL_UNLOCK();
goto out;
case T_DIVIDE|T_USER:
sv.sival_ptr = (void *)frame->tf_rip;
KERNEL_LOCK();
trapsignal(p, SIGFPE, type &~ T_USER, FPE_INTDIV, sv);
KERNEL_UNLOCK();
goto out;
case T_ARITHTRAP|T_USER:
case T_XMM|T_USER:
fputrap(frame);
goto out;
case T_PAGEFLT: /* allow page faults in kernel mode */
if (p == NULL)
goto we_re_toast;
cr2 = rcr2();
KERNEL_LOCK();
/* This will only trigger if SMEP is enabled */
if (cr2 <= VM_MAXUSER_ADDRESS && frame->tf_err & PGEX_I)
panic("attempt to execute user address %p "
"in supervisor mode", (void *)cr2);
goto faultcommon;
case T_PAGEFLT|T_USER: { /* page fault */
vaddr_t va, fa;
struct vmspace *vm;
struct vm_map *map;
vm_prot_t ftype;
extern struct vm_map *kernel_map;
cr2 = rcr2();
KERNEL_LOCK();
faultcommon:
vm = p->p_vmspace;
if (vm == NULL)
goto we_re_toast;
fa = cr2;
va = trunc_page((vaddr_t)cr2);
/*
* It is only a kernel address space fault iff:
* 1. (type & T_USER) == 0 and
* 2. pcb_onfault not set or
* 3. pcb_onfault set but supervisor space fault
* The last can occur during an exec() copyin where the
* argument space is lazy-allocated.
*/
if (type == T_PAGEFLT && va >= VM_MIN_KERNEL_ADDRESS)
map = kernel_map;
else
map = &vm->vm_map;
if (frame->tf_err & PGEX_W)
ftype = VM_PROT_WRITE;
else if (frame->tf_err & PGEX_I)
ftype = VM_PROT_EXECUTE;
else
ftype = VM_PROT_READ;
#ifdef DIAGNOSTIC
if (map == kernel_map && va == 0) {
printf("trap: bad kernel access at %lx\n", va);
goto we_re_toast;
}
#endif
/* Fault the original page in. */
onfault = pcb->pcb_onfault;
pcb->pcb_onfault = NULL;
error = uvm_fault(map, va, frame->tf_err & PGEX_P?
VM_FAULT_PROTECT : VM_FAULT_INVALID, ftype);
pcb->pcb_onfault = onfault;
if (error == 0) {
if (map != kernel_map)
uvm_grow(p, va);
if (type == T_PAGEFLT) {
KERNEL_UNLOCK();
return;
}
KERNEL_UNLOCK();
goto out;
}
if (error == EACCES) {
error = EFAULT;
}
if (type == T_PAGEFLT) {
if (pcb->pcb_onfault != 0) {
KERNEL_UNLOCK();
goto copyfault;
}
printf("uvm_fault(%p, 0x%lx, 0, %d) -> %x\n",
map, va, ftype, error);
goto we_re_toast;
}
if (error == ENOMEM) {
printf("UVM: pid %d (%s), uid %d killed: out of swap\n",
p->p_pid, p->p_comm,
p->p_cred && p->p_ucred ?
(int)p->p_ucred->cr_uid : -1);
sv.sival_ptr = (void *)fa;
trapsignal(p, SIGKILL, T_PAGEFLT, SEGV_MAPERR, sv);
} else {
#ifdef TRAP_SIGDEBUG
printf("pid %d (%s): SEGV at rip %lx addr %lx\n",
p->p_pid, p->p_comm, frame->tf_rip, va);
frame_dump(frame);
#endif
sv.sival_ptr = (void *)fa;
trapsignal(p, SIGSEGV, T_PAGEFLT, SEGV_MAPERR, sv);
}
KERNEL_UNLOCK();
break;
}
case T_TRCTRAP:
goto we_re_toast;
case T_BPTFLT|T_USER: /* bpt instruction fault */
case T_TRCTRAP|T_USER: /* trace trap */
#ifdef MATH_EMULATE
trace:
#endif
KERNEL_LOCK();
trapsignal(p, SIGTRAP, type &~ T_USER, TRAP_BRKPT, sv);
KERNEL_UNLOCK();
break;
#if NISA > 0
case T_NMI:
#if defined(KGDB) || defined(DDB)
/* NMI can be hooked up to a pushbutton for debugging */
printf ("NMI ... going to debugger\n");
#ifdef KGDB
if (kgdb_trap(type, frame))
return;
#endif
#ifdef DDB
if (kdb_trap(type, 0, frame))
return;
#endif
#endif /* KGDB || DDB */
/* machine/parity/power fail/"kitchen sink" faults */
if (x86_nmi() != 0)
goto we_re_toast;
else
return;
#endif /* NISA > 0 */
}
if ((type & T_USER) == 0)
return;
out:
userret(p);
}
#ifdef TRAP_SIGDEBUG
static void
frame_dump(struct trapframe *tf)
{
printf("rip %p rsp %p rfl %p\n",
(void *)tf->tf_rip, (void *)tf->tf_rsp, (void *)tf->tf_rflags);
printf("rdi %p rsi %p rdx %p\n",
(void *)tf->tf_rdi, (void *)tf->tf_rsi, (void *)tf->tf_rdx);
printf("rcx %p r8 %p r9 %p\n",
(void *)tf->tf_rcx, (void *)tf->tf_r8, (void *)tf->tf_r9);
printf("r10 %p r11 %p r12 %p\n",
(void *)tf->tf_r10, (void *)tf->tf_r11, (void *)tf->tf_r12);
printf("r13 %p r14 %p r15 %p\n",
(void *)tf->tf_r13, (void *)tf->tf_r14, (void *)tf->tf_r15);
printf("rbp %p rbx %p rax %p\n",
(void *)tf->tf_rbp, (void *)tf->tf_rbx, (void *)tf->tf_rax);
}
#endif
/*
* syscall(frame):
* System call request from POSIX system call gate interface to kernel.
*/
void
syscall(struct trapframe *frame)
{
caddr_t params;
const struct sysent *callp;
struct proc *p;
int error;
int nsys;
size_t argsize, argoff;
register_t code, args[9], rval[2], *argp;
uvmexp.syscalls++;
p = curproc;
code = frame->tf_rax;
callp = p->p_emul->e_sysent;
nsys = p->p_emul->e_nsysent;
argp = &args[0];
argoff = 0;
switch (code) {
case SYS_syscall:
case SYS___syscall:
/*
* Code is first argument, followed by actual args.
*/
code = frame->tf_rdi;
argp = &args[1];
argoff = 1;
break;
default:
break;
}
if (code < 0 || code >= nsys)
callp += p->p_emul->e_nosys;
else
callp += code;
argsize = (callp->sy_argsize >> 3) + argoff;
if (argsize) {
switch (MIN(argsize, 6)) {
case 6:
args[5] = frame->tf_r9;
case 5:
args[4] = frame->tf_r8;
case 4:
args[3] = frame->tf_r10;
case 3:
args[2] = frame->tf_rdx;
case 2:
args[1] = frame->tf_rsi;
case 1:
args[0] = frame->tf_rdi;
break;
default:
panic("impossible syscall argsize");
}
if (argsize > 6) {
argsize -= 6;
params = (caddr_t)frame->tf_rsp + sizeof(register_t);
if ((error = copyin(params, &args[6], argsize << 3)))
goto bad;
}
}
rval[0] = 0;
rval[1] = frame->tf_rdx;
error = mi_syscall(p, code, callp, argp, rval);
switch (error) {
case 0:
frame->tf_rax = rval[0];
frame->tf_rdx = rval[1];
frame->tf_rflags &= ~PSL_C; /* carry bit */
break;
case ERESTART:
/*
* The offset to adjust the PC by depends on whether we entered
* the kernel through the trap or call gate. We pushed the
* size of the instruction into tf_err on entry.
*/
frame->tf_rip -= frame->tf_err;
break;
case EJUSTRETURN:
/* nothing to do */
break;
default:
bad:
frame->tf_rax = error;
frame->tf_rflags |= PSL_C; /* carry bit */
break;
}
mi_syscall_return(p, code, error, rval);
}
void
child_return(void *arg)
{
struct proc *p = arg;
struct trapframe *tf = p->p_md.md_regs;
tf->tf_rax = 0;
tf->tf_rdx = 1;
tf->tf_rflags &= ~PSL_C;
KERNEL_UNLOCK();
mi_child_return(p);
}
|