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1 /*
2 * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
3 *
4 * @APPLE_LICENSE_HEADER_START@
5 *
6 * The contents of this file constitute Original Code as defined in and
7 * are subject to the Apple Public Source License Version 1.1 (the
8 * "License"). You may not use this file except in compliance with the
9 * License. Please obtain a copy of the License at
10 * http://www.apple.com/publicsource and read it before using this file.
11 *
12 * This Original Code and all software distributed under the License are
13 * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
14 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
15 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
16 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the
17 * License for the specific language governing rights and limitations
18 * under the License.
19 *
20 * @APPLE_LICENSE_HEADER_END@
21 */
22 /*
23 * @OSF_COPYRIGHT@
24 */
25 /*
26 * Mach Operating System
27 * Copyright (c) 1991,1990,1989,1988 Carnegie Mellon University
28 * All Rights Reserved.
29 *
30 * Permission to use, copy, modify and distribute this software and its
31 * documentation is hereby granted, provided that both the copyright
32 * notice and this permission notice appear in all copies of the
33 * software, derivative works or modified versions, and any portions
34 * thereof, and that both notices appear in supporting documentation.
35 *
36 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
37 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
38 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
39 *
40 * Carnegie Mellon requests users of this software to return to
41 *
42 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
43 * School of Computer Science
44 * Carnegie Mellon University
45 * Pittsburgh PA 15213-3890
46 *
47 * any improvements or extensions that they make and grant Carnegie Mellon
48 * the rights to redistribute these changes.
49 */
50 /*
51 */
52 /*
53 * Hardware trap/fault handler.
54 */
55
56 #include <cpus.h>
57 #include <fast_idle.h>
58 #include <mach_kdb.h>
59 #include <mach_kgdb.h>
60 #include <mach_kdp.h>
61 #include <mach_ldebug.h>
62
63 #include <types.h>
64 #include <i386/eflags.h>
65 #include <i386/trap.h>
66 #include <i386/pmap.h>
67 #include <i386/fpu.h>
68
69 #include <mach/exception.h>
70 #include <mach/kern_return.h>
71 #include <mach/vm_param.h>
72 #include <mach/i386/thread_status.h>
73
74 #include <vm/vm_kern.h>
75 #include <vm/vm_fault.h>
76
77 #include <kern/etap_macros.h>
78 #include <kern/kern_types.h>
79 #include <kern/ast.h>
80 #include <kern/thread.h>
81 #include <kern/task.h>
82 #include <kern/sched.h>
83 #include <kern/sched_prim.h>
84 #include <kern/exception.h>
85 #include <kern/spl.h>
86 #include <kern/misc_protos.h>
87
88 #if MACH_KGDB
89 #include <kgdb/kgdb_defs.h>
90 #endif /* MACH_KGDB */
91
92 #include <i386/intel_read_fault.h>
93
94 #if MACH_KGDB
95 #include <kgdb/kgdb_defs.h>
96 #endif /* MACH_KGDB */
97
98 #if MACH_KDB
99 #include <ddb/db_watch.h>
100 #include <ddb/db_run.h>
101 #include <ddb/db_break.h>
102 #include <ddb/db_trap.h>
103 #endif /* MACH_KDB */
104
105 #include <string.h>
106
107 #include <i386/io_emulate.h>
108
109 /*
110 * Forward declarations
111 */
112 extern void user_page_fault_continue(
113 kern_return_t kr);
114
115 extern boolean_t v86_assist(
116 thread_t thread,
117 struct i386_saved_state *regs);
118
119 extern boolean_t check_io_fault(
120 struct i386_saved_state *regs);
121
122 extern int inst_fetch(
123 int eip,
124 int cs);
125
126 void
127 thread_syscall_return(
128 kern_return_t ret)
129 {
130 register thread_act_t thr_act = current_act();
131 register struct i386_saved_state *regs = USER_REGS(thr_act);
132 regs->eax = ret;
133 thread_exception_return();
134 /*NOTREACHED*/
135 }
136
137
138 #if MACH_KDB
139 boolean_t debug_all_traps_with_kdb = FALSE;
140 extern struct db_watchpoint *db_watchpoint_list;
141 extern boolean_t db_watchpoints_inserted;
142 extern boolean_t db_breakpoints_inserted;
143
144 void
145 thread_kdb_return(void)
146 {
147 register thread_act_t thr_act = current_act();
148 register thread_t cur_thr = current_thread();
149 register struct i386_saved_state *regs = USER_REGS(thr_act);
150
151 if (kdb_trap(regs->trapno, regs->err, regs)) {
152 #if MACH_LDEBUG
153 assert(cur_thr->mutex_count == 0);
154 #endif /* MACH_LDEBUG */
155 check_simple_locks();
156 thread_exception_return();
157 /*NOTREACHED*/
158 }
159 }
160 boolean_t let_ddb_vm_fault = FALSE;
161
162 #if NCPUS > 1
163 extern int kdb_active[NCPUS];
164 #endif /* NCPUS > 1 */
165
166 #endif /* MACH_KDB */
167
168 void
169 user_page_fault_continue(
170 kern_return_t kr)
171 {
172 register thread_act_t thr_act = current_act();
173 register thread_t cur_thr = current_thread();
174 register struct i386_saved_state *regs = USER_REGS(thr_act);
175
176 if ((kr == KERN_SUCCESS) || (kr == KERN_ABORTED)) {
177 #if MACH_KDB
178 if (!db_breakpoints_inserted) {
179 db_set_breakpoints();
180 }
181 if (db_watchpoint_list &&
182 db_watchpoints_inserted &&
183 (regs->err & T_PF_WRITE) &&
184 db_find_watchpoint(thr_act->map,
185 (vm_offset_t)regs->cr2,
186 regs))
187 kdb_trap(T_WATCHPOINT, 0, regs);
188 #endif /* MACH_KDB */
189 thread_exception_return();
190 /*NOTREACHED*/
191 }
192
193 #if MACH_KDB
194 if (debug_all_traps_with_kdb &&
195 kdb_trap(regs->trapno, regs->err, regs)) {
196 #if MACH_LDEBUG
197 assert(cur_thr->mutex_count == 0);
198 #endif /* MACH_LDEBUG */
199 check_simple_locks();
200 thread_exception_return();
201 /*NOTREACHED*/
202 }
203 #endif /* MACH_KDB */
204
205 i386_exception(EXC_BAD_ACCESS, kr, regs->cr2);
206 /*NOTREACHED*/
207 }
208
209 /*
210 * Fault recovery in copyin/copyout routines.
211 */
212 struct recovery {
213 int fault_addr;
214 int recover_addr;
215 };
216
217 extern struct recovery recover_table[];
218 extern struct recovery recover_table_end[];
219
220 /*
221 * Recovery from Successful fault in copyout does not
222 * return directly - it retries the pte check, since
223 * the 386 ignores write protection in kernel mode.
224 */
225 extern struct recovery retry_table[];
226 extern struct recovery retry_table_end[];
227
228 char * trap_type[] = {TRAP_NAMES};
229 int TRAP_TYPES = sizeof(trap_type)/sizeof(trap_type[0]);
230
231 /*
232 * Trap from kernel mode. Only page-fault errors are recoverable,
233 * and then only in special circumstances. All other errors are
234 * fatal. Return value indicates if trap was handled.
235 */
236 boolean_t
237 kernel_trap(
238 register struct i386_saved_state *regs)
239 {
240 int exc;
241 int code;
242 int subcode;
243 int interruptible;
244 register int type;
245 vm_map_t map;
246 kern_return_t result;
247 register thread_t thread;
248 thread_act_t thr_act;
249 etap_data_t probe_data;
250 pt_entry_t *pte;
251 extern vm_offset_t vm_last_phys;
252
253 type = regs->trapno;
254 code = regs->err;
255 thread = current_thread();
256 thr_act = current_act();
257
258 ETAP_DATA_LOAD(probe_data[0], regs->trapno);
259 ETAP_DATA_LOAD(probe_data[1], MACH_PORT_NULL);
260 ETAP_DATA_LOAD(probe_data[2], MACH_PORT_NULL);
261 ETAP_PROBE_DATA(ETAP_P_EXCEPTION,
262 0,
263 thread,
264 &probe_data,
265 ETAP_DATA_ENTRY*3);
266
267 switch (type) {
268 case T_PREEMPT:
269 return (TRUE);
270
271 case T_NO_FPU:
272 fpnoextflt();
273 return (TRUE);
274
275 case T_FPU_FAULT:
276 fpextovrflt();
277 return (TRUE);
278
279 case T_FLOATING_POINT_ERROR:
280 fpexterrflt();
281 return (TRUE);
282
283 case T_PAGE_FAULT:
284 /*
285 * If the current map is a submap of the kernel map,
286 * and the address is within that map, fault on that
287 * map. If the same check is done in vm_fault
288 * (vm_map_lookup), we may deadlock on the kernel map
289 * lock.
290 */
291 #if MACH_KDB
292 mp_disable_preemption();
293 if (db_active
294 #if NCPUS > 1
295 && kdb_active[cpu_number()]
296 #endif /* NCPUS > 1 */
297 && !let_ddb_vm_fault) {
298 /*
299 * Force kdb to handle this one.
300 */
301 mp_enable_preemption();
302 return (FALSE);
303 }
304 mp_enable_preemption();
305 #endif /* MACH_KDB */
306 subcode = regs->cr2; /* get faulting address */
307
308 if (subcode > LINEAR_KERNEL_ADDRESS) {
309 map = kernel_map;
310 subcode -= LINEAR_KERNEL_ADDRESS;
311 } else if (thr_act == THR_ACT_NULL || thread == THREAD_NULL)
312 map = kernel_map;
313 else {
314 map = thr_act->map;
315 }
316
317 #if MACH_KDB
318 /*
319 * Check for watchpoint on kernel static data.
320 * vm_fault would fail in this case
321 */
322 if (map == kernel_map &&
323 db_watchpoint_list &&
324 db_watchpoints_inserted &&
325 (code & T_PF_WRITE) &&
326 (vm_offset_t)subcode < vm_last_phys &&
327 ((*(pte = pmap_pte(kernel_pmap, (vm_offset_t)subcode))) &
328 INTEL_PTE_WRITE) == 0) {
329 *pte = INTEL_PTE_VALID | INTEL_PTE_WRITE |
330 pa_to_pte(trunc_page((vm_offset_t)subcode) -
331 VM_MIN_KERNEL_ADDRESS);
332 result = KERN_SUCCESS;
333 } else
334 #endif /* MACH_KDB */
335 {
336 /*
337 * Since the 386 ignores write protection in
338 * kernel mode, always try for write permission
339 * first. If that fails and the fault was a
340 * read fault, retry with read permission.
341 */
342 if (map == kernel_map) {
343 register struct recovery *rp;
344
345 interruptible = THREAD_UNINT;
346 for (rp = recover_table; rp < recover_table_end; rp++) {
347 if (regs->eip == rp->fault_addr) {
348 interruptible = THREAD_ABORTSAFE;
349 break;
350 }
351 }
352 }
353
354 result = vm_fault(map,
355 trunc_page((vm_offset_t)subcode),
356 VM_PROT_READ|VM_PROT_WRITE,
357 FALSE,
358 (map == kernel_map) ? interruptible : THREAD_ABORTSAFE, NULL, 0);
359 }
360 #if MACH_KDB
361 if (result == KERN_SUCCESS) {
362 /* Look for watchpoints */
363 if (db_watchpoint_list &&
364 db_watchpoints_inserted &&
365 (code & T_PF_WRITE) &&
366 db_find_watchpoint(map,
367 (vm_offset_t)subcode, regs))
368 kdb_trap(T_WATCHPOINT, 0, regs);
369 }
370 else
371 #endif /* MACH_KDB */
372 if ((code & T_PF_WRITE) == 0 &&
373 result == KERN_PROTECTION_FAILURE)
374 {
375 /*
376 * Must expand vm_fault by hand,
377 * so that we can ask for read-only access
378 * but enter a (kernel)writable mapping.
379 */
380 result = intel_read_fault(map,
381 trunc_page((vm_offset_t)subcode));
382 }
383
384 if (result == KERN_SUCCESS) {
385 /*
386 * Certain faults require that we back up
387 * the EIP.
388 */
389 register struct recovery *rp;
390
391 for (rp = retry_table; rp < retry_table_end; rp++) {
392 if (regs->eip == rp->fault_addr) {
393 regs->eip = rp->recover_addr;
394 break;
395 }
396 }
397 return (TRUE);
398 }
399
400 /* fall through */
401
402 case T_GENERAL_PROTECTION:
403
404 /*
405 * If there is a failure recovery address
406 * for this fault, go there.
407 */
408 {
409 register struct recovery *rp;
410
411 for (rp = recover_table;
412 rp < recover_table_end;
413 rp++) {
414 if (regs->eip == rp->fault_addr) {
415 regs->eip = rp->recover_addr;
416 return (TRUE);
417 }
418 }
419 }
420
421 /*
422 * Check thread recovery address also -
423 * v86 assist uses it.
424 */
425 if (thread->recover) {
426 regs->eip = thread->recover;
427 thread->recover = 0;
428 return (TRUE);
429 }
430
431 /*
432 * Unanticipated page-fault errors in kernel
433 * should not happen.
434 */
435 /* fall through... */
436
437 default:
438 /*
439 * ...and return failure, so that locore can call into
440 * debugger.
441 */
442 #if MACH_KDP
443 kdp_i386_trap(type, regs, result, regs->cr2);
444 #endif
445 return (FALSE);
446 }
447 return (TRUE);
448 }
449
450 /*
451 * Called if both kernel_trap() and kdb_trap() fail.
452 */
453 void
454 panic_trap(
455 register struct i386_saved_state *regs)
456 {
457 int code;
458 register int type;
459
460 type = regs->trapno;
461 code = regs->err;
462
463 printf("trap type %d, code = %x, pc = %x\n",
464 type, code, regs->eip);
465 panic("trap");
466 }
467
468
469 /*
470 * Trap from user mode.
471 */
472 void
473 user_trap(
474 register struct i386_saved_state *regs)
475 {
476 int exc;
477 int code;
478 int subcode;
479 register int type;
480 vm_map_t map;
481 vm_prot_t prot;
482 kern_return_t result;
483 register thread_act_t thr_act = current_act();
484 thread_t thread = (thr_act ? thr_act->thread : THREAD_NULL);
485 boolean_t kernel_act = thr_act->kernel_loaded;
486 etap_data_t probe_data;
487
488 if (regs->efl & EFL_VM) {
489 /*
490 * If hardware assist can handle exception,
491 * continue execution.
492 */
493 if (v86_assist(thread, regs))
494 return;
495 }
496
497 type = regs->trapno;
498 code = 0;
499 subcode = 0;
500
501 switch (type) {
502
503 case T_DIVIDE_ERROR:
504 exc = EXC_ARITHMETIC;
505 code = EXC_I386_DIV;
506 break;
507
508 case T_DEBUG:
509 exc = EXC_BREAKPOINT;
510 code = EXC_I386_SGL;
511 break;
512
513 case T_INT3:
514 exc = EXC_BREAKPOINT;
515 code = EXC_I386_BPT;
516 break;
517
518 case T_OVERFLOW:
519 exc = EXC_ARITHMETIC;
520 code = EXC_I386_INTO;
521 break;
522
523 case T_OUT_OF_BOUNDS:
524 exc = EXC_SOFTWARE;
525 code = EXC_I386_BOUND;
526 break;
527
528 case T_INVALID_OPCODE:
529 exc = EXC_BAD_INSTRUCTION;
530 code = EXC_I386_INVOP;
531 break;
532
533 case T_NO_FPU:
534 case 32: /* XXX */
535 fpnoextflt();
536 return;
537
538 case T_FPU_FAULT:
539 fpextovrflt();
540 return;
541
542 case 10: /* invalid TSS == iret with NT flag set */
543 exc = EXC_BAD_INSTRUCTION;
544 code = EXC_I386_INVTSSFLT;
545 subcode = regs->err & 0xffff;
546 break;
547
548 case T_SEGMENT_NOT_PRESENT:
549 exc = EXC_BAD_INSTRUCTION;
550 code = EXC_I386_SEGNPFLT;
551 subcode = regs->err & 0xffff;
552 break;
553
554 case T_STACK_FAULT:
555 exc = EXC_BAD_INSTRUCTION;
556 code = EXC_I386_STKFLT;
557 subcode = regs->err & 0xffff;
558 break;
559
560 case T_GENERAL_PROTECTION:
561 if (!(regs->efl & EFL_VM)) {
562 if (check_io_fault(regs))
563 return;
564 }
565 exc = EXC_BAD_INSTRUCTION;
566 code = EXC_I386_GPFLT;
567 subcode = regs->err & 0xffff;
568 break;
569
570 case T_PAGE_FAULT:
571 subcode = regs->cr2;
572 prot = VM_PROT_READ|VM_PROT_WRITE;
573 if (kernel_act == FALSE) {
574 if (!(regs->err & T_PF_WRITE))
575 prot = VM_PROT_READ;
576 (void) user_page_fault_continue(vm_fault(thr_act->map,
577 trunc_page((vm_offset_t)subcode),
578 prot,
579 FALSE,
580 THREAD_ABORTSAFE, NULL, 0));
581 /* NOTREACHED */
582 }
583 else {
584 if (subcode > LINEAR_KERNEL_ADDRESS) {
585 map = kernel_map;
586 subcode -= LINEAR_KERNEL_ADDRESS;
587 }
588 result = vm_fault(thr_act->map,
589 trunc_page((vm_offset_t)subcode),
590 prot,
591 FALSE,
592 (map == kernel_map) ? THREAD_UNINT : THREAD_ABORTSAFE, NULL, 0);
593 if ((result != KERN_SUCCESS) && (result != KERN_ABORTED)) {
594 /*
595 * Must expand vm_fault by hand,
596 * so that we can ask for read-only access
597 * but enter a (kernel) writable mapping.
598 */
599 result = intel_read_fault(thr_act->map,
600 trunc_page((vm_offset_t)subcode));
601 }
602 user_page_fault_continue(result);
603 /*NOTREACHED*/
604 }
605 break;
606
607 case T_FLOATING_POINT_ERROR:
608 fpexterrflt();
609 return;
610
611 default:
612 #if MACH_KGDB
613 Debugger("Unanticipated user trap");
614 return;
615 #endif /* MACH_KGDB */
616 #if MACH_KDB
617 if (kdb_trap(type, regs->err, regs))
618 return;
619 #endif /* MACH_KDB */
620 printf("user trap type %d, code = %x, pc = %x\n",
621 type, regs->err, regs->eip);
622 panic("user trap");
623 return;
624 }
625
626 #if MACH_KDB
627 if (debug_all_traps_with_kdb &&
628 kdb_trap(type, regs->err, regs))
629 return;
630 #endif /* MACH_KDB */
631
632 #if ETAP_EVENT_MONITOR
633 if (thread != THREAD_NULL) {
634 ETAP_DATA_LOAD(probe_data[0], regs->trapno);
635 ETAP_DATA_LOAD(probe_data[1],
636 thr_act->exc_actions[exc].port);
637 ETAP_DATA_LOAD(probe_data[2],
638 thr_act->task->exc_actions[exc].port);
639 ETAP_PROBE_DATA(ETAP_P_EXCEPTION,
640 0,
641 thread,
642 &probe_data,
643 ETAP_DATA_ENTRY*3);
644 }
645 #endif /* ETAP_EVENT_MONITOR */
646
647 i386_exception(exc, code, subcode);
648 /*NOTREACHED*/
649 }
650
651 /*
652 * V86 mode assist for interrupt handling.
653 */
654 boolean_t v86_assist_on = TRUE;
655 boolean_t v86_unsafe_ok = FALSE;
656 boolean_t v86_do_sti_cli = TRUE;
657 boolean_t v86_do_sti_immediate = FALSE;
658
659 #define V86_IRET_PENDING 0x4000
660
661 int cli_count = 0;
662 int sti_count = 0;
663
664 boolean_t
665 v86_assist(
666 thread_t thread,
667 register struct i386_saved_state *regs)
668 {
669 register struct v86_assist_state *v86 = &thread->top_act->mact.pcb->ims.v86s;
670
671 /*
672 * Build an 8086 address. Use only when off is known to be 16 bits.
673 */
674 #define Addr8086(seg,off) ((((seg) & 0xffff) << 4) + (off))
675
676 #define EFL_V86_SAFE ( EFL_OF | EFL_DF | EFL_TF \
677 | EFL_SF | EFL_ZF | EFL_AF \
678 | EFL_PF | EFL_CF )
679 struct iret_32 {
680 int eip;
681 int cs;
682 int eflags;
683 };
684 struct iret_16 {
685 unsigned short ip;
686 unsigned short cs;
687 unsigned short flags;
688 };
689 union iret_struct {
690 struct iret_32 iret_32;
691 struct iret_16 iret_16;
692 };
693
694 struct int_vec {
695 unsigned short ip;
696 unsigned short cs;
697 };
698
699 if (!v86_assist_on)
700 return FALSE;
701
702 /*
703 * If delayed STI pending, enable interrupts.
704 * Turn off tracing if on only to delay STI.
705 */
706 if (v86->flags & V86_IF_PENDING) {
707 v86->flags &= ~V86_IF_PENDING;
708 v86->flags |= EFL_IF;
709 if ((v86->flags & EFL_TF) == 0)
710 regs->efl &= ~EFL_TF;
711 }
712
713 if (regs->trapno == T_DEBUG) {
714
715 if (v86->flags & EFL_TF) {
716 /*
717 * Trace flag was also set - it has priority
718 */
719 return FALSE; /* handle as single-step */
720 }
721 /*
722 * Fall through to check for interrupts.
723 */
724 }
725 else if (regs->trapno == T_GENERAL_PROTECTION) {
726 /*
727 * General protection error - must be an 8086 instruction
728 * to emulate.
729 */
730 register int eip;
731 boolean_t addr_32 = FALSE;
732 boolean_t data_32 = FALSE;
733 int io_port;
734
735 /*
736 * Set up error handler for bad instruction/data
737 * fetches.
738 */
739 __asm__("movl $(addr_error), %0" : : "m" (thread->recover));
740
741 eip = regs->eip;
742 while (TRUE) {
743 unsigned char opcode;
744
745 if (eip > 0xFFFF) {
746 thread->recover = 0;
747 return FALSE; /* GP fault: IP out of range */
748 }
749
750 opcode = *(unsigned char *)Addr8086(regs->cs,eip);
751 eip++;
752 switch (opcode) {
753 case 0xf0: /* lock */
754 case 0xf2: /* repne */
755 case 0xf3: /* repe */
756 case 0x2e: /* cs */
757 case 0x36: /* ss */
758 case 0x3e: /* ds */
759 case 0x26: /* es */
760 case 0x64: /* fs */
761 case 0x65: /* gs */
762 /* ignore prefix */
763 continue;
764
765 case 0x66: /* data size */
766 data_32 = TRUE;
767 continue;
768
769 case 0x67: /* address size */
770 addr_32 = TRUE;
771 continue;
772
773 case 0xe4: /* inb imm */
774 case 0xe5: /* inw imm */
775 case 0xe6: /* outb imm */
776 case 0xe7: /* outw imm */
777 io_port = *(unsigned char *)Addr8086(regs->cs, eip);
778 eip++;
779 goto do_in_out;
780
781 case 0xec: /* inb dx */
782 case 0xed: /* inw dx */
783 case 0xee: /* outb dx */
784 case 0xef: /* outw dx */
785 case 0x6c: /* insb */
786 case 0x6d: /* insw */
787 case 0x6e: /* outsb */
788 case 0x6f: /* outsw */
789 io_port = regs->edx & 0xffff;
790
791 do_in_out:
792 if (!data_32)
793 opcode |= 0x6600; /* word IO */
794
795 switch (emulate_io(regs, opcode, io_port)) {
796 case EM_IO_DONE:
797 /* instruction executed */
798 break;
799 case EM_IO_RETRY:
800 /* port mapped, retry instruction */
801 thread->recover = 0;
802 return TRUE;
803 case EM_IO_ERROR:
804 /* port not mapped */
805 thread->recover = 0;
806 return FALSE;
807 }
808 break;
809
810 case 0xfa: /* cli */
811 if (!v86_do_sti_cli) {
812 thread->recover = 0;
813 return (FALSE);
814 }
815
816 v86->flags &= ~EFL_IF;
817 /* disable simulated interrupts */
818 cli_count++;
819 break;
820
821 case 0xfb: /* sti */
822 if (!v86_do_sti_cli) {
823 thread->recover = 0;
824 return (FALSE);
825 }
826
827 if ((v86->flags & EFL_IF) == 0) {
828 if (v86_do_sti_immediate) {
829 v86->flags |= EFL_IF;
830 } else {
831 v86->flags |= V86_IF_PENDING;
832 regs->efl |= EFL_TF;
833 }
834 /* single step to set IF next inst. */
835 }
836 sti_count++;
837 break;
838
839 case 0x9c: /* pushf */
840 {
841 int flags;
842 vm_offset_t sp;
843 int size;
844
845 flags = regs->efl;
846 if ((v86->flags & EFL_IF) == 0)
847 flags &= ~EFL_IF;
848
849 if ((v86->flags & EFL_TF) == 0)
850 flags &= ~EFL_TF;
851 else flags |= EFL_TF;
852
853 sp = regs->uesp;
854 if (!addr_32)
855 sp &= 0xffff;
856 else if (sp > 0xffff)
857 goto stack_error;
858 size = (data_32) ? 4 : 2;
859 if (sp < size)
860 goto stack_error;
861 sp -= size;
862 if (copyout((char *)&flags,
863 (char *)Addr8086(regs->ss,sp),
864 size))
865 goto addr_error;
866 if (addr_32)
867 regs->uesp = sp;
868 else
869 regs->uesp = (regs->uesp & 0xffff0000) | sp;
870 break;
871 }
872
873 case 0x9d: /* popf */
874 {
875 vm_offset_t sp;
876 int nflags;
877
878 sp = regs->uesp;
879 if (!addr_32)
880 sp &= 0xffff;
881 else if (sp > 0xffff)
882 goto stack_error;
883
884 if (data_32) {
885 if (sp > 0xffff - sizeof(int))
886 goto stack_error;
887 nflags = *(int *)Addr8086(regs->ss,sp);
888 sp += sizeof(int);
889 }
890 else {
891 if (sp > 0xffff - sizeof(short))
892 goto stack_error;
893 nflags = *(unsigned short *)
894 Addr8086(regs->ss,sp);
895 sp += sizeof(short);
896 }
897 if (addr_32)
898 regs->uesp = sp;
899 else
900 regs->uesp = (regs->uesp & 0xffff0000) | sp;
901
902 if (v86->flags & V86_IRET_PENDING) {
903 v86->flags = nflags & (EFL_TF | EFL_IF);
904 v86->flags |= V86_IRET_PENDING;
905 } else {
906 v86->flags = nflags & (EFL_TF | EFL_IF);
907 }
908 regs->efl = (regs->efl & ~EFL_V86_SAFE)
909 | (nflags & EFL_V86_SAFE);
910 break;
911 }
912 case 0xcf: /* iret */
913 {
914 vm_offset_t sp;
915 int nflags;
916 int size;
917 union iret_struct iret_struct;
918
919 v86->flags &= ~V86_IRET_PENDING;
920 sp = regs->uesp;
921 if (!addr_32)
922 sp &= 0xffff;
923 else if (sp > 0xffff)
924 goto stack_error;
925
926 if (data_32) {
927 if (sp > 0xffff - sizeof(struct iret_32))
928 goto stack_error;
929 iret_struct.iret_32 =
930 *(struct iret_32 *) Addr8086(regs->ss,sp);
931 sp += sizeof(struct iret_32);
932 }
933 else {
934 if (sp > 0xffff - sizeof(struct iret_16))
935 goto stack_error;
936 iret_struct.iret_16 =
937 *(struct iret_16 *) Addr8086(regs->ss,sp);
938 sp += sizeof(struct iret_16);
939 }
940 if (addr_32)
941 regs->uesp = sp;
942 else
943 regs->uesp = (regs->uesp & 0xffff0000) | sp;
944
945 if (data_32) {
946 eip = iret_struct.iret_32.eip;
947 regs->cs = iret_struct.iret_32.cs & 0xffff;
948 nflags = iret_struct.iret_32.eflags;
949 }
950 else {
951 eip = iret_struct.iret_16.ip;
952 regs->cs = iret_struct.iret_16.cs;
953 nflags = iret_struct.iret_16.flags;
954 }
955
956 v86->flags = nflags & (EFL_TF | EFL_IF);
957 regs->efl = (regs->efl & ~EFL_V86_SAFE)
958 | (nflags & EFL_V86_SAFE);
959 break;
960 }
961 default:
962 /*
963 * Instruction not emulated here.
964 */
965 thread->recover = 0;
966 return FALSE;
967 }
968 break; /* exit from 'while TRUE' */
969 }
970 regs->eip = (regs->eip & 0xffff0000 | eip);
971 }
972 else {
973 /*
974 * Not a trap we handle.
975 */
976 thread->recover = 0;
977 return FALSE;
978 }
979
980 if ((v86->flags & EFL_IF) && ((v86->flags & V86_IRET_PENDING)==0)) {
981
982 struct v86_interrupt_table *int_table;
983 int int_count;
984 int vec;
985 int i;
986
987 int_table = (struct v86_interrupt_table *) v86->int_table;
988 int_count = v86->int_count;
989
990 vec = 0;
991 for (i = 0; i < int_count; int_table++, i++) {
992 if (!int_table->mask && int_table->count > 0) {
993 int_table->count--;
994 vec = int_table->vec;
995 break;
996 }
997 }
998 if (vec != 0) {
999 /*
1000 * Take this interrupt
1001 */
1002 vm_offset_t sp;
1003 struct iret_16 iret_16;
1004 struct int_vec int_vec;
1005
1006 sp = regs->uesp & 0xffff;
1007 if (sp < sizeof(struct iret_16))
1008 goto stack_error;
1009 sp -= sizeof(struct iret_16);
1010 iret_16.ip = regs->eip;
1011 iret_16.cs = regs->cs;
1012 iret_16.flags = regs->efl & 0xFFFF;
1013 if ((v86->flags & EFL_TF) == 0)
1014 iret_16.flags &= ~EFL_TF;
1015 else iret_16.flags |= EFL_TF;
1016
1017 (void) memcpy((char *) &int_vec,
1018 (char *) (sizeof(struct int_vec) * vec),
1019 sizeof (struct int_vec));
1020 if (copyout((char *)&iret_16,
1021 (char *)Addr8086(regs->ss,sp),
1022 sizeof(struct iret_16)))
1023 goto addr_error;
1024 regs->uesp = (regs->uesp & 0xFFFF0000) | (sp & 0xffff);
1025 regs->eip = int_vec.ip;
1026 regs->cs = int_vec.cs;
1027 regs->efl &= ~EFL_TF;
1028 v86->flags &= ~(EFL_IF | EFL_TF);
1029 v86->flags |= V86_IRET_PENDING;
1030 }
1031 }
1032
1033 thread->recover = 0;
1034 return TRUE;
1035
1036 /*
1037 * On address error, report a page fault.
1038 * XXX report GP fault - we don`t save
1039 * the faulting address.
1040 */
1041 addr_error:
1042 __asm__("addr_error:;");
1043 thread->recover = 0;
1044 return FALSE;
1045
1046 /*
1047 * On stack address error, return stack fault (12).
1048 */
1049 stack_error:
1050 thread->recover = 0;
1051 regs->trapno = T_STACK_FAULT;
1052 return FALSE;
1053 }
1054
1055 /*
1056 * Handle AST traps for i386.
1057 * Check for delayed floating-point exception from
1058 * AT-bus machines.
1059 */
1060
1061 extern void log_thread_action (thread_t, char *);
1062
1063 void
1064 i386_astintr(int preemption)
1065 {
1066 int mycpu;
1067 ast_t mask = AST_ALL;
1068 spl_t s;
1069 thread_t self = current_thread();
1070
1071 s = splsched(); /* block interrupts to check reasons */
1072 mp_disable_preemption();
1073 mycpu = cpu_number();
1074 if (need_ast[mycpu] & AST_I386_FP) {
1075 /*
1076 * AST was for delayed floating-point exception -
1077 * FP interrupt occured while in kernel.
1078 * Turn off this AST reason and handle the FPU error.
1079 */
1080
1081 ast_off(AST_I386_FP);
1082 mp_enable_preemption();
1083 splx(s);
1084
1085 fpexterrflt();
1086 }
1087 else {
1088 /*
1089 * Not an FPU trap. Handle the AST.
1090 * Interrupts are still blocked.
1091 */
1092
1093 #ifdef XXX
1094 if (preemption) {
1095
1096 /*
1097 * We don't want to process any AST if we were in
1098 * kernel-mode and the current thread is in any
1099 * funny state (waiting and/or suspended).
1100 */
1101
1102 thread_lock (self);
1103
1104 if (thread_not_preemptable(self) || self->preempt) {
1105 ast_off(AST_URGENT);
1106 thread_unlock (self);
1107 mp_enable_preemption();
1108 splx(s);
1109 return;
1110 }
1111 else mask = AST_PREEMPT;
1112 mp_enable_preemption();
1113
1114 /*
1115 self->preempt = TH_NOT_PREEMPTABLE;
1116 */
1117
1118 thread_unlock (self);
1119 } else {
1120 mp_enable_preemption();
1121 }
1122 #else
1123 mp_enable_preemption();
1124 #endif
1125
1126 ast_taken(mask, s
1127 #if FAST_IDLE
1128 ,NO_IDLE_THREAD
1129 #endif /* FAST_IDLE */
1130 );
1131 /*
1132 self->preempt = TH_PREEMPTABLE;
1133 */
1134 }
1135 }
1136
1137 /*
1138 * Handle exceptions for i386.
1139 *
1140 * If we are an AT bus machine, we must turn off the AST for a
1141 * delayed floating-point exception.
1142 *
1143 * If we are providing floating-point emulation, we may have
1144 * to retrieve the real register values from the floating point
1145 * emulator.
1146 */
1147 void
1148 i386_exception(
1149 int exc,
1150 int code,
1151 int subcode)
1152 {
1153 spl_t s;
1154 exception_data_type_t codes[EXCEPTION_CODE_MAX];
1155
1156 /*
1157 * Turn off delayed FPU error handling.
1158 */
1159 s = splsched();
1160 mp_disable_preemption();
1161 ast_off(AST_I386_FP);
1162 mp_enable_preemption();
1163 splx(s);
1164
1165 codes[0] = code; /* new exception interface */
1166 codes[1] = subcode;
1167 exception(exc, codes, 2);
1168 /*NOTREACHED*/
1169 }
1170
1171 boolean_t
1172 check_io_fault(
1173 struct i386_saved_state *regs)
1174 {
1175 int eip, opcode, io_port;
1176 boolean_t data_16 = FALSE;
1177
1178 /*
1179 * Get the instruction.
1180 */
1181 eip = regs->eip;
1182
1183 for (;;) {
1184 opcode = inst_fetch(eip, regs->cs);
1185 eip++;
1186 switch (opcode) {
1187 case 0x66: /* data-size prefix */
1188 data_16 = TRUE;
1189 continue;
1190
1191 case 0xf3: /* rep prefix */
1192 case 0x26: /* es */
1193 case 0x2e: /* cs */
1194 case 0x36: /* ss */
1195 case 0x3e: /* ds */
1196 case 0x64: /* fs */
1197 case 0x65: /* gs */
1198 continue;
1199
1200 case 0xE4: /* inb imm */
1201 case 0xE5: /* inl imm */
1202 case 0xE6: /* outb imm */
1203 case 0xE7: /* outl imm */
1204 /* port is immediate byte */
1205 io_port = inst_fetch(eip, regs->cs);
1206 eip++;
1207 break;
1208
1209 case 0xEC: /* inb dx */
1210 case 0xED: /* inl dx */
1211 case 0xEE: /* outb dx */
1212 case 0xEF: /* outl dx */
1213 case 0x6C: /* insb */
1214 case 0x6D: /* insl */
1215 case 0x6E: /* outsb */
1216 case 0x6F: /* outsl */
1217 /* port is in DX register */
1218 io_port = regs->edx & 0xFFFF;
1219 break;
1220
1221 default:
1222 return FALSE;
1223 }
1224 break;
1225 }
1226
1227 if (data_16)
1228 opcode |= 0x6600; /* word IO */
1229
1230 switch (emulate_io(regs, opcode, io_port)) {
1231 case EM_IO_DONE:
1232 /* instruction executed */
1233 regs->eip = eip;
1234 return TRUE;
1235
1236 case EM_IO_RETRY:
1237 /* port mapped, retry instruction */
1238 return TRUE;
1239
1240 case EM_IO_ERROR:
1241 /* port not mapped */
1242 return FALSE;
1243 }
1244 return FALSE;
1245 }
1246
1247 void
1248 kernel_preempt_check (void)
1249 {
1250 mp_disable_preemption();
1251 if ((need_ast[cpu_number()] & AST_URGENT) &&
1252 #if NCPUS > 1
1253 get_interrupt_level() == 1
1254 #else /* NCPUS > 1 */
1255 get_interrupt_level() == 0
1256 #endif /* NCPUS > 1 */
1257 ) {
1258 mp_enable_preemption_no_check();
1259 __asm__ volatile (" int $0xff");
1260 } else {
1261 mp_enable_preemption_no_check();
1262 }
1263 }
1264
1265 #if MACH_KDB
1266
1267 extern void db_i386_state(struct i386_saved_state *regs);
1268
1269 #include <ddb/db_output.h>
1270
1271 void
1272 db_i386_state(
1273 struct i386_saved_state *regs)
1274 {
1275 db_printf("eip %8x\n", regs->eip);
1276 db_printf("trap %8x\n", regs->trapno);
1277 db_printf("err %8x\n", regs->err);
1278 db_printf("efl %8x\n", regs->efl);
1279 db_printf("ebp %8x\n", regs->ebp);
1280 db_printf("esp %8x\n", regs->esp);
1281 db_printf("uesp %8x\n", regs->uesp);
1282 db_printf("cs %8x\n", regs->cs & 0xff);
1283 db_printf("ds %8x\n", regs->ds & 0xff);
1284 db_printf("es %8x\n", regs->es & 0xff);
1285 db_printf("fs %8x\n", regs->fs & 0xff);
1286 db_printf("gs %8x\n", regs->gs & 0xff);
1287 db_printf("ss %8x\n", regs->ss & 0xff);
1288 db_printf("eax %8x\n", regs->eax);
1289 db_printf("ebx %8x\n", regs->ebx);
1290 db_printf("ecx %8x\n", regs->ecx);
1291 db_printf("edx %8x\n", regs->edx);
1292 db_printf("esi %8x\n", regs->esi);
1293 db_printf("edi %8x\n", regs->edi);
1294 }
1295
1296 #endif /* MACH_KDB */
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