Linux Audio

Check our new training course

Embedded Linux Audio

Check our new training course
with Creative Commons CC-BY-SA
lecture materials

Bootlin logo

Elixir Cross Referencer

Loading...
  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
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
/*
 * 'traps.c' handles hardware traps and faults after we have saved some
 * state in 'entry.S'.
 *
 *  SuperH version: Copyright (C) 1999 Niibe Yutaka
 *                  Copyright (C) 2000 Philipp Rumpf
 *                  Copyright (C) 2000 David Howells
 *                  Copyright (C) 2002 - 2006 Paul Mundt
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 */
#include <linux/kernel.h>
#include <linux/ptrace.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/module.h>
#include <linux/kallsyms.h>
#include <linux/io.h>
#include <linux/debug_locks.h>
#include <linux/limits.h>
#include <asm/system.h>
#include <asm/uaccess.h>

#ifdef CONFIG_SH_KGDB
#include <asm/kgdb.h>
#define CHK_REMOTE_DEBUG(regs)			\
{						\
	if (kgdb_debug_hook && !user_mode(regs))\
		(*kgdb_debug_hook)(regs);       \
}
#else
#define CHK_REMOTE_DEBUG(regs)
#endif

#ifdef CONFIG_CPU_SH2
# define TRAP_RESERVED_INST	4
# define TRAP_ILLEGAL_SLOT_INST	6
# define TRAP_ADDRESS_ERROR	9
# ifdef CONFIG_CPU_SH2A
#  define TRAP_DIVZERO_ERROR	17
#  define TRAP_DIVOVF_ERROR	18
# endif
#else
#define TRAP_RESERVED_INST	12
#define TRAP_ILLEGAL_SLOT_INST	13
#endif

static void dump_mem(const char *str, unsigned long bottom, unsigned long top)
{
	unsigned long p;
	int i;

	printk("%s(0x%08lx to 0x%08lx)\n", str, bottom, top);

	for (p = bottom & ~31; p < top; ) {
		printk("%04lx: ", p & 0xffff);

		for (i = 0; i < 8; i++, p += 4) {
			unsigned int val;

			if (p < bottom || p >= top)
				printk("         ");
			else {
				if (__get_user(val, (unsigned int __user *)p)) {
					printk("\n");
					return;
				}
				printk("%08x ", val);
			}
		}
		printk("\n");
	}
}

DEFINE_SPINLOCK(die_lock);

void die(const char * str, struct pt_regs * regs, long err)
{
	static int die_counter;

	console_verbose();
	spin_lock_irq(&die_lock);
	bust_spinlocks(1);

	printk("%s: %04lx [#%d]\n", str, err & 0xffff, ++die_counter);

	CHK_REMOTE_DEBUG(regs);
	print_modules();
	show_regs(regs);

	printk("Process: %s (pid: %d, stack limit = %p)\n",
	       current->comm, current->pid, task_stack_page(current) + 1);

	if (!user_mode(regs) || in_interrupt())
		dump_mem("Stack: ", regs->regs[15], THREAD_SIZE +
			 (unsigned long)task_stack_page(current));

	bust_spinlocks(0);
	spin_unlock_irq(&die_lock);
	do_exit(SIGSEGV);
}

static inline void die_if_kernel(const char *str, struct pt_regs *regs,
				 long err)
{
	if (!user_mode(regs))
		die(str, regs, err);
}

/*
 * try and fix up kernelspace address errors
 * - userspace errors just cause EFAULT to be returned, resulting in SEGV
 * - kernel/userspace interfaces cause a jump to an appropriate handler
 * - other kernel errors are bad
 * - return 0 if fixed-up, -EFAULT if non-fatal (to the kernel) fault
 */
static int die_if_no_fixup(const char * str, struct pt_regs * regs, long err)
{
	if (!user_mode(regs)) {
		const struct exception_table_entry *fixup;
		fixup = search_exception_tables(regs->pc);
		if (fixup) {
			regs->pc = fixup->fixup;
			return 0;
		}
		die(str, regs, err);
	}
	return -EFAULT;
}

#ifdef CONFIG_BUG
#ifdef CONFIG_DEBUG_BUGVERBOSE
static inline void do_bug_verbose(struct pt_regs *regs)
{
	struct bug_frame f;
	long len;

	if (__copy_from_user(&f, (const void __user *)regs->pc,
			     sizeof(struct bug_frame)))
		return;

	len = __strnlen_user(f.file, PATH_MAX) - 1;
	if (unlikely(len < 0 || len >= PATH_MAX))
		f.file = "<bad filename>";
	len = __strnlen_user(f.func, PATH_MAX) - 1;
	if (unlikely(len < 0 || len >= PATH_MAX))
		f.func = "<bad function>";

	printk(KERN_ALERT "kernel BUG in %s() at %s:%d!\n",
	       f.func, f.file, f.line);
}
#else
static inline void do_bug_verbose(struct pt_regs *regs)
{
}
#endif /* CONFIG_DEBUG_BUGVERBOSE */
#endif /* CONFIG_BUG */

void handle_BUG(struct pt_regs *regs)
{
	do_bug_verbose(regs);
	die("Kernel BUG", regs, TRAPA_BUG_OPCODE & 0xff);
}

/*
 * handle an instruction that does an unaligned memory access by emulating the
 * desired behaviour
 * - note that PC _may not_ point to the faulting instruction
 *   (if that instruction is in a branch delay slot)
 * - return 0 if emulation okay, -EFAULT on existential error
 */
static int handle_unaligned_ins(u16 instruction, struct pt_regs *regs)
{
	int ret, index, count;
	unsigned long *rm, *rn;
	unsigned char *src, *dst;

	index = (instruction>>8)&15;	/* 0x0F00 */
	rn = &regs->regs[index];

	index = (instruction>>4)&15;	/* 0x00F0 */
	rm = &regs->regs[index];

	count = 1<<(instruction&3);

	ret = -EFAULT;
	switch (instruction>>12) {
	case 0: /* mov.[bwl] to/from memory via r0+rn */
		if (instruction & 8) {
			/* from memory */
			src = (unsigned char*) *rm;
			src += regs->regs[0];
			dst = (unsigned char*) rn;
			*(unsigned long*)dst = 0;

#ifdef __LITTLE_ENDIAN__
			if (copy_from_user(dst, src, count))
				goto fetch_fault;

			if ((count == 2) && dst[1] & 0x80) {
				dst[2] = 0xff;
				dst[3] = 0xff;
			}
#else
			dst += 4-count;

			if (__copy_user(dst, src, count))
				goto fetch_fault;

			if ((count == 2) && dst[2] & 0x80) {
				dst[0] = 0xff;
				dst[1] = 0xff;
			}
#endif
		} else {
			/* to memory */
			src = (unsigned char*) rm;
#if !defined(__LITTLE_ENDIAN__)
			src += 4-count;
#endif
			dst = (unsigned char*) *rn;
			dst += regs->regs[0];

			if (copy_to_user(dst, src, count))
				goto fetch_fault;
		}
		ret = 0;
		break;

	case 1: /* mov.l Rm,@(disp,Rn) */
		src = (unsigned char*) rm;
		dst = (unsigned char*) *rn;
		dst += (instruction&0x000F)<<2;

		if (copy_to_user(dst,src,4))
			goto fetch_fault;
		ret = 0;
		break;

	case 2: /* mov.[bwl] to memory, possibly with pre-decrement */
		if (instruction & 4)
			*rn -= count;
		src = (unsigned char*) rm;
		dst = (unsigned char*) *rn;
#if !defined(__LITTLE_ENDIAN__)
		src += 4-count;
#endif
		if (copy_to_user(dst, src, count))
			goto fetch_fault;
		ret = 0;
		break;

	case 5: /* mov.l @(disp,Rm),Rn */
		src = (unsigned char*) *rm;
		src += (instruction&0x000F)<<2;
		dst = (unsigned char*) rn;
		*(unsigned long*)dst = 0;

		if (copy_from_user(dst,src,4))
			goto fetch_fault;
		ret = 0;
		break;

	case 6:	/* mov.[bwl] from memory, possibly with post-increment */
		src = (unsigned char*) *rm;
		if (instruction & 4)
			*rm += count;
		dst = (unsigned char*) rn;
		*(unsigned long*)dst = 0;

#ifdef __LITTLE_ENDIAN__
		if (copy_from_user(dst, src, count))
			goto fetch_fault;

		if ((count == 2) && dst[1] & 0x80) {
			dst[2] = 0xff;
			dst[3] = 0xff;
		}
#else
		dst += 4-count;

		if (copy_from_user(dst, src, count))
			goto fetch_fault;

		if ((count == 2) && dst[2] & 0x80) {
			dst[0] = 0xff;
			dst[1] = 0xff;
		}
#endif
		ret = 0;
		break;

	case 8:
		switch ((instruction&0xFF00)>>8) {
		case 0x81: /* mov.w R0,@(disp,Rn) */
			src = (unsigned char*) &regs->regs[0];
#if !defined(__LITTLE_ENDIAN__)
			src += 2;
#endif
			dst = (unsigned char*) *rm; /* called Rn in the spec */
			dst += (instruction&0x000F)<<1;

			if (copy_to_user(dst, src, 2))
				goto fetch_fault;
			ret = 0;
			break;

		case 0x85: /* mov.w @(disp,Rm),R0 */
			src = (unsigned char*) *rm;
			src += (instruction&0x000F)<<1;
			dst = (unsigned char*) &regs->regs[0];
			*(unsigned long*)dst = 0;

#if !defined(__LITTLE_ENDIAN__)
			dst += 2;
#endif

			if (copy_from_user(dst, src, 2))
				goto fetch_fault;

#ifdef __LITTLE_ENDIAN__
			if (dst[1] & 0x80) {
				dst[2] = 0xff;
				dst[3] = 0xff;
			}
#else
			if (dst[2] & 0x80) {
				dst[0] = 0xff;
				dst[1] = 0xff;
			}
#endif
			ret = 0;
			break;
		}
		break;
	}
	return ret;

 fetch_fault:
	/* Argh. Address not only misaligned but also non-existent.
	 * Raise an EFAULT and see if it's trapped
	 */
	return die_if_no_fixup("Fault in unaligned fixup", regs, 0);
}

/*
 * emulate the instruction in the delay slot
 * - fetches the instruction from PC+2
 */
static inline int handle_unaligned_delayslot(struct pt_regs *regs)
{
	u16 instruction;

	if (copy_from_user(&instruction, (u16 *)(regs->pc+2), 2)) {
		/* the instruction-fetch faulted */
		if (user_mode(regs))
			return -EFAULT;

		/* kernel */
		die("delay-slot-insn faulting in handle_unaligned_delayslot",
		    regs, 0);
	}

	return handle_unaligned_ins(instruction,regs);
}

/*
 * handle an instruction that does an unaligned memory access
 * - have to be careful of branch delay-slot instructions that fault
 *  SH3:
 *   - if the branch would be taken PC points to the branch
 *   - if the branch would not be taken, PC points to delay-slot
 *  SH4:
 *   - PC always points to delayed branch
 * - return 0 if handled, -EFAULT if failed (may not return if in kernel)
 */

/* Macros to determine offset from current PC for branch instructions */
/* Explicit type coercion is used to force sign extension where needed */
#define SH_PC_8BIT_OFFSET(instr) ((((signed char)(instr))*2) + 4)
#define SH_PC_12BIT_OFFSET(instr) ((((signed short)(instr<<4))>>3) + 4)

/*
 * XXX: SH-2A needs this too, but it needs an overhaul thanks to mixed 32-bit
 * opcodes..
 */
#ifndef CONFIG_CPU_SH2A
static int handle_unaligned_notify_count = 10;

static int handle_unaligned_access(u16 instruction, struct pt_regs *regs)
{
	u_int rm;
	int ret, index;

	index = (instruction>>8)&15;	/* 0x0F00 */
	rm = regs->regs[index];

	/* shout about the first ten userspace fixups */
	if (user_mode(regs) && handle_unaligned_notify_count>0) {
		handle_unaligned_notify_count--;

		printk(KERN_NOTICE "Fixing up unaligned userspace access "
		       "in \"%s\" pid=%d pc=0x%p ins=0x%04hx\n",
		       current->comm,current->pid,(u16*)regs->pc,instruction);
	}

	ret = -EFAULT;
	switch (instruction&0xF000) {
	case 0x0000:
		if (instruction==0x000B) {
			/* rts */
			ret = handle_unaligned_delayslot(regs);
			if (ret==0)
				regs->pc = regs->pr;
		}
		else if ((instruction&0x00FF)==0x0023) {
			/* braf @Rm */
			ret = handle_unaligned_delayslot(regs);
			if (ret==0)
				regs->pc += rm + 4;
		}
		else if ((instruction&0x00FF)==0x0003) {
			/* bsrf @Rm */
			ret = handle_unaligned_delayslot(regs);
			if (ret==0) {
				regs->pr = regs->pc + 4;
				regs->pc += rm + 4;
			}
		}
		else {
			/* mov.[bwl] to/from memory via r0+rn */
			goto simple;
		}
		break;

	case 0x1000: /* mov.l Rm,@(disp,Rn) */
		goto simple;

	case 0x2000: /* mov.[bwl] to memory, possibly with pre-decrement */
		goto simple;

	case 0x4000:
		if ((instruction&0x00FF)==0x002B) {
			/* jmp @Rm */
			ret = handle_unaligned_delayslot(regs);
			if (ret==0)
				regs->pc = rm;
		}
		else if ((instruction&0x00FF)==0x000B) {
			/* jsr @Rm */
			ret = handle_unaligned_delayslot(regs);
			if (ret==0) {
				regs->pr = regs->pc + 4;
				regs->pc = rm;
			}
		}
		else {
			/* mov.[bwl] to/from memory via r0+rn */
			goto simple;
		}
		break;

	case 0x5000: /* mov.l @(disp,Rm),Rn */
		goto simple;

	case 0x6000: /* mov.[bwl] from memory, possibly with post-increment */
		goto simple;

	case 0x8000: /* bf lab, bf/s lab, bt lab, bt/s lab */
		switch (instruction&0x0F00) {
		case 0x0100: /* mov.w R0,@(disp,Rm) */
			goto simple;
		case 0x0500: /* mov.w @(disp,Rm),R0 */
			goto simple;
		case 0x0B00: /* bf   lab - no delayslot*/
			break;
		case 0x0F00: /* bf/s lab */
			ret = handle_unaligned_delayslot(regs);
			if (ret==0) {
#if defined(CONFIG_CPU_SH4) || defined(CONFIG_SH7705_CACHE_32KB)
				if ((regs->sr & 0x00000001) != 0)
					regs->pc += 4; /* next after slot */
				else
#endif
					regs->pc += SH_PC_8BIT_OFFSET(instruction);
			}
			break;
		case 0x0900: /* bt   lab - no delayslot */
			break;
		case 0x0D00: /* bt/s lab */
			ret = handle_unaligned_delayslot(regs);
			if (ret==0) {
#if defined(CONFIG_CPU_SH4) || defined(CONFIG_SH7705_CACHE_32KB)
				if ((regs->sr & 0x00000001) == 0)
					regs->pc += 4; /* next after slot */
				else
#endif
					regs->pc += SH_PC_8BIT_OFFSET(instruction);
			}
			break;
		}
		break;

	case 0xA000: /* bra label */
		ret = handle_unaligned_delayslot(regs);
		if (ret==0)
			regs->pc += SH_PC_12BIT_OFFSET(instruction);
		break;

	case 0xB000: /* bsr label */
		ret = handle_unaligned_delayslot(regs);
		if (ret==0) {
			regs->pr = regs->pc + 4;
			regs->pc += SH_PC_12BIT_OFFSET(instruction);
		}
		break;
	}
	return ret;

	/* handle non-delay-slot instruction */
 simple:
	ret = handle_unaligned_ins(instruction,regs);
	if (ret==0)
		regs->pc += 2;
	return ret;
}
#endif /* CONFIG_CPU_SH2A */

#ifdef CONFIG_CPU_HAS_SR_RB
#define lookup_exception_vector(x)	\
	__asm__ __volatile__ ("stc r2_bank, %0\n\t" : "=r" ((x)))
#else
#define lookup_exception_vector(x)	\
	__asm__ __volatile__ ("mov r4, %0\n\t" : "=r" ((x)))
#endif

/*
 * Handle various address error exceptions:
 *  - instruction address error:
 *       misaligned PC
 *       PC >= 0x80000000 in user mode
 *  - data address error (read and write)
 *       misaligned data access
 *       access to >= 0x80000000 is user mode
 * Unfortuntaly we can't distinguish between instruction address error
 * and data address errors caused by read acceses.
 */
asmlinkage void do_address_error(struct pt_regs *regs,
				 unsigned long writeaccess,
				 unsigned long address)
{
	unsigned long error_code = 0;
	mm_segment_t oldfs;
	siginfo_t info;
#ifndef CONFIG_CPU_SH2A
	u16 instruction;
	int tmp;
#endif

	/* Intentional ifdef */
#ifdef CONFIG_CPU_HAS_SR_RB
	lookup_exception_vector(error_code);
#endif

	oldfs = get_fs();

	if (user_mode(regs)) {
		int si_code = BUS_ADRERR;

		local_irq_enable();

		/* bad PC is not something we can fix */
		if (regs->pc & 1) {
			si_code = BUS_ADRALN;
			goto uspace_segv;
		}

#ifndef CONFIG_CPU_SH2A
		set_fs(USER_DS);
		if (copy_from_user(&instruction, (u16 *)(regs->pc), 2)) {
			/* Argh. Fault on the instruction itself.
			   This should never happen non-SMP
			*/
			set_fs(oldfs);
			goto uspace_segv;
		}

		tmp = handle_unaligned_access(instruction, regs);
		set_fs(oldfs);

		if (tmp==0)
			return; /* sorted */
#endif

uspace_segv:
		printk(KERN_NOTICE "Sending SIGBUS to \"%s\" due to unaligned "
		       "access (PC %lx PR %lx)\n", current->comm, regs->pc,
		       regs->pr);

		info.si_signo = SIGBUS;
		info.si_errno = 0;
		info.si_code = si_code;
		info.si_addr = (void *) address;
		force_sig_info(SIGBUS, &info, current);
	} else {
		if (regs->pc & 1)
			die("unaligned program counter", regs, error_code);

#ifndef CONFIG_CPU_SH2A
		set_fs(KERNEL_DS);
		if (copy_from_user(&instruction, (u16 *)(regs->pc), 2)) {
			/* Argh. Fault on the instruction itself.
			   This should never happen non-SMP
			*/
			set_fs(oldfs);
			die("insn faulting in do_address_error", regs, 0);
		}

		handle_unaligned_access(instruction, regs);
		set_fs(oldfs);
#else
		printk(KERN_NOTICE "Killing process \"%s\" due to unaligned "
		       "access\n", current->comm);

		force_sig(SIGSEGV, current);
#endif
	}
}

#ifdef CONFIG_SH_DSP
/*
 *	SH-DSP support gerg@snapgear.com.
 */
int is_dsp_inst(struct pt_regs *regs)
{
	unsigned short inst;

	/*
	 * Safe guard if DSP mode is already enabled or we're lacking
	 * the DSP altogether.
	 */
	if (!(cpu_data->flags & CPU_HAS_DSP) || (regs->sr & SR_DSP))
		return 0;

	get_user(inst, ((unsigned short *) regs->pc));

	inst &= 0xf000;

	/* Check for any type of DSP or support instruction */
	if ((inst == 0xf000) || (inst == 0x4000))
		return 1;

	return 0;
}
#else
#define is_dsp_inst(regs)	(0)
#endif /* CONFIG_SH_DSP */

#ifdef CONFIG_CPU_SH2A
asmlinkage void do_divide_error(unsigned long r4, unsigned long r5,
				unsigned long r6, unsigned long r7,
				struct pt_regs __regs)
{
	struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
	siginfo_t info;

	switch (r4) {
	case TRAP_DIVZERO_ERROR:
		info.si_code = FPE_INTDIV;
		break;
	case TRAP_DIVOVF_ERROR:
		info.si_code = FPE_INTOVF;
		break;
	}

	force_sig_info(SIGFPE, &info, current);
}
#endif

/* arch/sh/kernel/cpu/sh4/fpu.c */
extern int do_fpu_inst(unsigned short, struct pt_regs *);
extern asmlinkage void do_fpu_state_restore(unsigned long r4, unsigned long r5,
		unsigned long r6, unsigned long r7, struct pt_regs __regs);

asmlinkage void do_reserved_inst(unsigned long r4, unsigned long r5,
				unsigned long r6, unsigned long r7,
				struct pt_regs __regs)
{
	struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
	unsigned long error_code;
	struct task_struct *tsk = current;

#ifdef CONFIG_SH_FPU_EMU
	unsigned short inst = 0;
	int err;

	get_user(inst, (unsigned short*)regs->pc);

	err = do_fpu_inst(inst, regs);
	if (!err) {
		regs->pc += 2;
		return;
	}
	/* not a FPU inst. */
#endif

#ifdef CONFIG_SH_DSP
	/* Check if it's a DSP instruction */
	if (is_dsp_inst(regs)) {
		/* Enable DSP mode, and restart instruction. */
		regs->sr |= SR_DSP;
		return;
	}
#endif

	lookup_exception_vector(error_code);

	local_irq_enable();
	CHK_REMOTE_DEBUG(regs);
	force_sig(SIGILL, tsk);
	die_if_no_fixup("reserved instruction", regs, error_code);
}

#ifdef CONFIG_SH_FPU_EMU
static int emulate_branch(unsigned short inst, struct pt_regs* regs)
{
	/*
	 * bfs: 8fxx: PC+=d*2+4;
	 * bts: 8dxx: PC+=d*2+4;
	 * bra: axxx: PC+=D*2+4;
	 * bsr: bxxx: PC+=D*2+4  after PR=PC+4;
	 * braf:0x23: PC+=Rn*2+4;
	 * bsrf:0x03: PC+=Rn*2+4 after PR=PC+4;
	 * jmp: 4x2b: PC=Rn;
	 * jsr: 4x0b: PC=Rn      after PR=PC+4;
	 * rts: 000b: PC=PR;
	 */
	if ((inst & 0xfd00) == 0x8d00) {
		regs->pc += SH_PC_8BIT_OFFSET(inst);
		return 0;
	}

	if ((inst & 0xe000) == 0xa000) {
		regs->pc += SH_PC_12BIT_OFFSET(inst);
		return 0;
	}

	if ((inst & 0xf0df) == 0x0003) {
		regs->pc += regs->regs[(inst & 0x0f00) >> 8] + 4;
		return 0;
	}

	if ((inst & 0xf0df) == 0x400b) {
		regs->pc = regs->regs[(inst & 0x0f00) >> 8];
		return 0;
	}

	if ((inst & 0xffff) == 0x000b) {
		regs->pc = regs->pr;
		return 0;
	}

	return 1;
}
#endif

asmlinkage void do_illegal_slot_inst(unsigned long r4, unsigned long r5,
				unsigned long r6, unsigned long r7,
				struct pt_regs __regs)
{
	struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
	unsigned long error_code;
	struct task_struct *tsk = current;
#ifdef CONFIG_SH_FPU_EMU
	unsigned short inst = 0;

	get_user(inst, (unsigned short *)regs->pc + 1);
	if (!do_fpu_inst(inst, regs)) {
		get_user(inst, (unsigned short *)regs->pc);
		if (!emulate_branch(inst, regs))
			return;
		/* fault in branch.*/
	}
	/* not a FPU inst. */
#endif

	lookup_exception_vector(error_code);

	local_irq_enable();
	CHK_REMOTE_DEBUG(regs);
	force_sig(SIGILL, tsk);
	die_if_no_fixup("illegal slot instruction", regs, error_code);
}

asmlinkage void do_exception_error(unsigned long r4, unsigned long r5,
				   unsigned long r6, unsigned long r7,
				   struct pt_regs __regs)
{
	struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
	long ex;

	lookup_exception_vector(ex);
	die_if_kernel("exception", regs, ex);
}

#if defined(CONFIG_SH_STANDARD_BIOS)
void *gdb_vbr_vector;

static inline void __init gdb_vbr_init(void)
{
	register unsigned long vbr;

	/*
	 * Read the old value of the VBR register to initialise
	 * the vector through which debug and BIOS traps are
	 * delegated by the Linux trap handler.
	 */
	asm volatile("stc vbr, %0" : "=r" (vbr));

	gdb_vbr_vector = (void *)(vbr + 0x100);
	printk("Setting GDB trap vector to 0x%08lx\n",
	       (unsigned long)gdb_vbr_vector);
}
#endif

void __init per_cpu_trap_init(void)
{
	extern void *vbr_base;

#ifdef CONFIG_SH_STANDARD_BIOS
	gdb_vbr_init();
#endif

	/* NOTE: The VBR value should be at P1
	   (or P2, virtural "fixed" address space).
	   It's definitely should not in physical address.  */

	asm volatile("ldc	%0, vbr"
		     : /* no output */
		     : "r" (&vbr_base)
		     : "memory");
}

void *set_exception_table_vec(unsigned int vec, void *handler)
{
	extern void *exception_handling_table[];
	void *old_handler;

	old_handler = exception_handling_table[vec];
	exception_handling_table[vec] = handler;
	return old_handler;
}

extern asmlinkage void address_error_handler(unsigned long r4, unsigned long r5,
					     unsigned long r6, unsigned long r7,
					     struct pt_regs __regs);

void __init trap_init(void)
{
	set_exception_table_vec(TRAP_RESERVED_INST, do_reserved_inst);
	set_exception_table_vec(TRAP_ILLEGAL_SLOT_INST, do_illegal_slot_inst);

#if defined(CONFIG_CPU_SH4) && !defined(CONFIG_SH_FPU) || \
    defined(CONFIG_SH_FPU_EMU)
	/*
	 * For SH-4 lacking an FPU, treat floating point instructions as
	 * reserved. They'll be handled in the math-emu case, or faulted on
	 * otherwise.
	 */
	set_exception_table_evt(0x800, do_reserved_inst);
	set_exception_table_evt(0x820, do_illegal_slot_inst);
#elif defined(CONFIG_SH_FPU)
	set_exception_table_evt(0x800, do_fpu_state_restore);
	set_exception_table_evt(0x820, do_fpu_state_restore);
#endif

#ifdef CONFIG_CPU_SH2
	set_exception_table_vec(TRAP_ADDRESS_ERROR, address_error_handler);
#endif
#ifdef CONFIG_CPU_SH2A
	set_exception_table_vec(TRAP_DIVZERO_ERROR, do_divide_error);
	set_exception_table_vec(TRAP_DIVOVF_ERROR, do_divide_error);
#endif

	/* Setup VBR for boot cpu */
	per_cpu_trap_init();
}

void show_trace(struct task_struct *tsk, unsigned long *sp,
		struct pt_regs *regs)
{
	unsigned long addr;

	if (regs && user_mode(regs))
		return;

	printk("\nCall trace: ");
#ifdef CONFIG_KALLSYMS
	printk("\n");
#endif

	while (!kstack_end(sp)) {
		addr = *sp++;
		if (kernel_text_address(addr))
			print_ip_sym(addr);
	}

	printk("\n");

	if (!tsk)
		tsk = current;

	debug_show_held_locks(tsk);
}

void show_stack(struct task_struct *tsk, unsigned long *sp)
{
	unsigned long stack;

	if (!tsk)
		tsk = current;
	if (tsk == current)
		sp = (unsigned long *)current_stack_pointer;
	else
		sp = (unsigned long *)tsk->thread.sp;

	stack = (unsigned long)sp;
	dump_mem("Stack: ", stack, THREAD_SIZE +
		 (unsigned long)task_stack_page(tsk));
	show_trace(tsk, sp, NULL);
}

void dump_stack(void)
{
	show_stack(NULL, NULL);
}
EXPORT_SYMBOL(dump_stack);