summaryrefslogtreecommitdiff
path: root/arch/parisc/kernel/ptrace.c
blob: f642ba378ffa5fdbc827678e3ec2927ddd80ebf1 (plain)
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
// SPDX-License-Identifier: GPL-2.0
/*
 * Kernel support for the ptrace() and syscall tracing interfaces.
 *
 * Copyright (C) 2000 Hewlett-Packard Co, Linuxcare Inc.
 * Copyright (C) 2000 Matthew Wilcox <matthew@wil.cx>
 * Copyright (C) 2000 David Huggins-Daines <dhd@debian.org>
 * Copyright (C) 2008-2016 Helge Deller <deller@gmx.de>
 */

#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/elf.h>
#include <linux/errno.h>
#include <linux/ptrace.h>
#include <linux/tracehook.h>
#include <linux/user.h>
#include <linux/personality.h>
#include <linux/regset.h>
#include <linux/security.h>
#include <linux/seccomp.h>
#include <linux/compat.h>
#include <linux/signal.h>
#include <linux/audit.h>

#include <linux/uaccess.h>
#include <asm/pgtable.h>
#include <asm/processor.h>
#include <asm/asm-offsets.h>

/* PSW bits we allow the debugger to modify */
#define USER_PSW_BITS	(PSW_N | PSW_B | PSW_V | PSW_CB)

#define CREATE_TRACE_POINTS
#include <trace/events/syscalls.h>

/*
 * These are our native regset flavors.
 */
enum parisc_regset {
	REGSET_GENERAL,
	REGSET_FP
};

/*
 * Called by kernel/ptrace.c when detaching..
 *
 * Make sure single step bits etc are not set.
 */
void ptrace_disable(struct task_struct *task)
{
	clear_tsk_thread_flag(task, TIF_SINGLESTEP);
	clear_tsk_thread_flag(task, TIF_BLOCKSTEP);

	/* make sure the trap bits are not set */
	pa_psw(task)->r = 0;
	pa_psw(task)->t = 0;
	pa_psw(task)->h = 0;
	pa_psw(task)->l = 0;
}

/*
 * The following functions are called by ptrace_resume() when
 * enabling or disabling single/block tracing.
 */
void user_disable_single_step(struct task_struct *task)
{
	ptrace_disable(task);
}

void user_enable_single_step(struct task_struct *task)
{
	clear_tsk_thread_flag(task, TIF_BLOCKSTEP);
	set_tsk_thread_flag(task, TIF_SINGLESTEP);

	if (pa_psw(task)->n) {
		/* Nullified, just crank over the queue. */
		task_regs(task)->iaoq[0] = task_regs(task)->iaoq[1];
		task_regs(task)->iasq[0] = task_regs(task)->iasq[1];
		task_regs(task)->iaoq[1] = task_regs(task)->iaoq[0] + 4;
		pa_psw(task)->n = 0;
		pa_psw(task)->x = 0;
		pa_psw(task)->y = 0;
		pa_psw(task)->z = 0;
		pa_psw(task)->b = 0;
		ptrace_disable(task);
		/* Don't wake up the task, but let the
		   parent know something happened. */
		force_sig_fault_to_task(SIGTRAP, TRAP_TRACE,
					(void __user *) (task_regs(task)->iaoq[0] & ~3),
					task);
		/* notify_parent(task, SIGCHLD); */
		return;
	}

	/* Enable recovery counter traps.  The recovery counter
	 * itself will be set to zero on a task switch.  If the
	 * task is suspended on a syscall then the syscall return
	 * path will overwrite the recovery counter with a suitable
	 * value such that it traps once back in user space.  We
	 * disable interrupts in the tasks PSW here also, to avoid
	 * interrupts while the recovery counter is decrementing.
	 */
	pa_psw(task)->r = 1;
	pa_psw(task)->t = 0;
	pa_psw(task)->h = 0;
	pa_psw(task)->l = 0;
}

void user_enable_block_step(struct task_struct *task)
{
	clear_tsk_thread_flag(task, TIF_SINGLESTEP);
	set_tsk_thread_flag(task, TIF_BLOCKSTEP);

	/* Enable taken branch trap. */
	pa_psw(task)->r = 0;
	pa_psw(task)->t = 1;
	pa_psw(task)->h = 0;
	pa_psw(task)->l = 0;
}

long arch_ptrace(struct task_struct *child, long request,
		 unsigned long addr, unsigned long data)
{
	unsigned long __user *datap = (unsigned long __user *)data;
	unsigned long tmp;
	long ret = -EIO;

	switch (request) {

	/* Read the word at location addr in the USER area.  For ptraced
	   processes, the kernel saves all regs on a syscall. */
	case PTRACE_PEEKUSR:
		if ((addr & (sizeof(unsigned long)-1)) ||
		     addr >= sizeof(struct pt_regs))
			break;
		tmp = *(unsigned long *) ((char *) task_regs(child) + addr);
		ret = put_user(tmp, datap);
		break;

	/* Write the word at location addr in the USER area.  This will need
	   to change when the kernel no longer saves all regs on a syscall.
	   FIXME.  There is a problem at the moment in that r3-r18 are only
	   saved if the process is ptraced on syscall entry, and even then
	   those values are overwritten by actual register values on syscall
	   exit. */
	case PTRACE_POKEUSR:
		/* Some register values written here may be ignored in
		 * entry.S:syscall_restore_rfi; e.g. iaoq is written with
		 * r31/r31+4, and not with the values in pt_regs.
		 */
		if (addr == PT_PSW) {
			/* Allow writing to Nullify, Divide-step-correction,
			 * and carry/borrow bits.
			 * BEWARE, if you set N, and then single step, it won't
			 * stop on the nullified instruction.
			 */
			data &= USER_PSW_BITS;
			task_regs(child)->gr[0] &= ~USER_PSW_BITS;
			task_regs(child)->gr[0] |= data;
			ret = 0;
			break;
		}

		if ((addr & (sizeof(unsigned long)-1)) ||
		     addr >= sizeof(struct pt_regs))
			break;
		if ((addr >= PT_GR1 && addr <= PT_GR31) ||
				addr == PT_IAOQ0 || addr == PT_IAOQ1 ||
				(addr >= PT_FR0 && addr <= PT_FR31 + 4) ||
				addr == PT_SAR) {
			*(unsigned long *) ((char *) task_regs(child) + addr) = data;
			ret = 0;
		}
		break;

	case PTRACE_GETREGS:	/* Get all gp regs from the child. */
		return copy_regset_to_user(child,
					   task_user_regset_view(current),
					   REGSET_GENERAL,
					   0, sizeof(struct user_regs_struct),
					   datap);

	case PTRACE_SETREGS:	/* Set all gp regs in the child. */
		return copy_regset_from_user(child,
					     task_user_regset_view(current),
					     REGSET_GENERAL,
					     0, sizeof(struct user_regs_struct),
					     datap);

	case PTRACE_GETFPREGS:	/* Get the child FPU state. */
		return copy_regset_to_user(child,
					   task_user_regset_view(current),
					   REGSET_FP,
					   0, sizeof(struct user_fp_struct),
					   datap);

	case PTRACE_SETFPREGS:	/* Set the child FPU state. */
		return copy_regset_from_user(child,
					     task_user_regset_view(current),
					     REGSET_FP,
					     0, sizeof(struct user_fp_struct),
					     datap);

	default:
		ret = ptrace_request(child, request, addr, data);
		break;
	}

	return ret;
}


#ifdef CONFIG_COMPAT

/* This function is needed to translate 32 bit pt_regs offsets in to
 * 64 bit pt_regs offsets.  For example, a 32 bit gdb under a 64 bit kernel
 * will request offset 12 if it wants gr3, but the lower 32 bits of
 * the 64 bit kernels view of gr3 will be at offset 28 (3*8 + 4).
 * This code relies on a 32 bit pt_regs being comprised of 32 bit values
 * except for the fp registers which (a) are 64 bits, and (b) follow
 * the gr registers at the start of pt_regs.  The 32 bit pt_regs should
 * be half the size of the 64 bit pt_regs, plus 32*4 to allow for fr[]
 * being 64 bit in both cases.
 */

static compat_ulong_t translate_usr_offset(compat_ulong_t offset)
{
	if (offset < 0)
		return sizeof(struct pt_regs);
	else if (offset <= 32*4)	/* gr[0..31] */
		return offset * 2 + 4;
	else if (offset <= 32*4+32*8)	/* gr[0..31] + fr[0..31] */
		return offset + 32*4;
	else if (offset < sizeof(struct pt_regs)/2 + 32*4)
		return offset * 2 + 4 - 32*8;
	else
		return sizeof(struct pt_regs);
}

long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
			compat_ulong_t addr, compat_ulong_t data)
{
	compat_uint_t tmp;
	long ret = -EIO;

	switch (request) {

	case PTRACE_PEEKUSR:
		if (addr & (sizeof(compat_uint_t)-1))
			break;
		addr = translate_usr_offset(addr);
		if (addr >= sizeof(struct pt_regs))
			break;

		tmp = *(compat_uint_t *) ((char *) task_regs(child) + addr);
		ret = put_user(tmp, (compat_uint_t *) (unsigned long) data);
		break;

	/* Write the word at location addr in the USER area.  This will need
	   to change when the kernel no longer saves all regs on a syscall.
	   FIXME.  There is a problem at the moment in that r3-r18 are only
	   saved if the process is ptraced on syscall entry, and even then
	   those values are overwritten by actual register values on syscall
	   exit. */
	case PTRACE_POKEUSR:
		/* Some register values written here may be ignored in
		 * entry.S:syscall_restore_rfi; e.g. iaoq is written with
		 * r31/r31+4, and not with the values in pt_regs.
		 */
		if (addr == PT_PSW) {
			/* Since PT_PSW==0, it is valid for 32 bit processes
			 * under 64 bit kernels as well.
			 */
			ret = arch_ptrace(child, request, addr, data);
		} else {
			if (addr & (sizeof(compat_uint_t)-1))
				break;
			addr = translate_usr_offset(addr);
			if (addr >= sizeof(struct pt_regs))
				break;
			if (addr >= PT_FR0 && addr <= PT_FR31 + 4) {
				/* Special case, fp regs are 64 bits anyway */
				*(__u64 *) ((char *) task_regs(child) + addr) = data;
				ret = 0;
			}
			else if ((addr >= PT_GR1+4 && addr <= PT_GR31+4) ||
					addr == PT_IAOQ0+4 || addr == PT_IAOQ1+4 ||
					addr == PT_SAR+4) {
				/* Zero the top 32 bits */
				*(__u32 *) ((char *) task_regs(child) + addr - 4) = 0;
				*(__u32 *) ((char *) task_regs(child) + addr) = data;
				ret = 0;
			}
		}
		break;

	default:
		ret = compat_ptrace_request(child, request, addr, data);
		break;
	}

	return ret;
}
#endif

long do_syscall_trace_enter(struct pt_regs *regs)
{
	if (test_thread_flag(TIF_SYSCALL_TRACE)) {
		int rc = tracehook_report_syscall_entry(regs);

		/*
		 * As tracesys_next does not set %r28 to -ENOSYS
		 * when %r20 is set to -1, initialize it here.
		 */
		regs->gr[28] = -ENOSYS;

		if (rc) {
			/*
			 * A nonzero return code from
			 * tracehook_report_syscall_entry() tells us
			 * to prevent the syscall execution.  Skip
			 * the syscall call and the syscall restart handling.
			 *
			 * Note that the tracer may also just change
			 * regs->gr[20] to an invalid syscall number,
			 * that is handled by tracesys_next.
			 */
			regs->gr[20] = -1UL;
			return -1;
		}
	}

	/* Do the secure computing check after ptrace. */
	if (secure_computing(NULL) == -1)
		return -1;

#ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
		trace_sys_enter(regs, regs->gr[20]);
#endif

#ifdef CONFIG_64BIT
	if (!is_compat_task())
		audit_syscall_entry(regs->gr[20], regs->gr[26], regs->gr[25],
				    regs->gr[24], regs->gr[23]);
	else
#endif
		audit_syscall_entry(regs->gr[20] & 0xffffffff,
			regs->gr[26] & 0xffffffff,
			regs->gr[25] & 0xffffffff,
			regs->gr[24] & 0xffffffff,
			regs->gr[23] & 0xffffffff);

	/*
	 * Sign extend the syscall number to 64bit since it may have been
	 * modified by a compat ptrace call
	 */
	return (int) ((u32) regs->gr[20]);
}

void do_syscall_trace_exit(struct pt_regs *regs)
{
	int stepping = test_thread_flag(TIF_SINGLESTEP) ||
		test_thread_flag(TIF_BLOCKSTEP);

	audit_syscall_exit(regs);

#ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
		trace_sys_exit(regs, regs->gr[20]);
#endif

	if (stepping || test_thread_flag(TIF_SYSCALL_TRACE))
		tracehook_report_syscall_exit(regs, stepping);
}


/*
 * regset functions.
 */

static int fpr_get(struct task_struct *target,
		     const struct user_regset *regset,
		     unsigned int pos, unsigned int count,
		     void *kbuf, void __user *ubuf)
{
	struct pt_regs *regs = task_regs(target);
	__u64 *k = kbuf;
	__u64 __user *u = ubuf;
	__u64 reg;

	pos /= sizeof(reg);
	count /= sizeof(reg);

	if (kbuf)
		for (; count > 0 && pos < ELF_NFPREG; --count)
			*k++ = regs->fr[pos++];
	else
		for (; count > 0 && pos < ELF_NFPREG; --count)
			if (__put_user(regs->fr[pos++], u++))
				return -EFAULT;

	kbuf = k;
	ubuf = u;
	pos *= sizeof(reg);
	count *= sizeof(reg);
	return user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
					ELF_NFPREG * sizeof(reg), -1);
}

static int fpr_set(struct task_struct *target,
		     const struct user_regset *regset,
		     unsigned int pos, unsigned int count,
		     const void *kbuf, const void __user *ubuf)
{
	struct pt_regs *regs = task_regs(target);
	const __u64 *k = kbuf;
	const __u64 __user *u = ubuf;
	__u64 reg;

	pos /= sizeof(reg);
	count /= sizeof(reg);

	if (kbuf)
		for (; count > 0 && pos < ELF_NFPREG; --count)
			regs->fr[pos++] = *k++;
	else
		for (; count > 0 && pos < ELF_NFPREG; --count) {
			if (__get_user(reg, u++))
				return -EFAULT;
			regs->fr[pos++] = reg;
		}

	kbuf = k;
	ubuf = u;
	pos *= sizeof(reg);
	count *= sizeof(reg);
	return user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
					 ELF_NFPREG * sizeof(reg), -1);
}

#define RI(reg) (offsetof(struct user_regs_struct,reg) / sizeof(long))

static unsigned long get_reg(struct pt_regs *regs, int num)
{
	switch (num) {
	case RI(gr[0]) ... RI(gr[31]):	return regs->gr[num - RI(gr[0])];
	case RI(sr[0]) ... RI(sr[7]):	return regs->sr[num - RI(sr[0])];
	case RI(iasq[0]):		return regs->iasq[0];
	case RI(iasq[1]):		return regs->iasq[1];
	case RI(iaoq[0]):		return regs->iaoq[0];
	case RI(iaoq[1]):		return regs->iaoq[1];
	case RI(sar):			return regs->sar;
	case RI(iir):			return regs->iir;
	case RI(isr):			return regs->isr;
	case RI(ior):			return regs->ior;
	case RI(ipsw):			return regs->ipsw;
	case RI(cr27):			return regs->cr27;
	case RI(cr0):			return mfctl(0);
	case RI(cr24):			return mfctl(24);
	case RI(cr25):			return mfctl(25);
	case RI(cr26):			return mfctl(26);
	case RI(cr28):			return mfctl(28);
	case RI(cr29):			return mfctl(29);
	case RI(cr30):			return mfctl(30);
	case RI(cr31):			return mfctl(31);
	case RI(cr8):			return mfctl(8);
	case RI(cr9):			return mfctl(9);
	case RI(cr12):			return mfctl(12);
	case RI(cr13):			return mfctl(13);
	case RI(cr10):			return mfctl(10);
	case RI(cr15):			return mfctl(15);
	default:			return 0;
	}
}

static void set_reg(struct pt_regs *regs, int num, unsigned long val)
{
	switch (num) {
	case RI(gr[0]): /*
			 * PSW is in gr[0].
			 * Allow writing to Nullify, Divide-step-correction,
			 * and carry/borrow bits.
			 * BEWARE, if you set N, and then single step, it won't
			 * stop on the nullified instruction.
			 */
			val &= USER_PSW_BITS;
			regs->gr[0] &= ~USER_PSW_BITS;
			regs->gr[0] |= val;
			return;
	case RI(gr[1]) ... RI(gr[31]):
			regs->gr[num - RI(gr[0])] = val;
			return;
	case RI(iaoq[0]):
	case RI(iaoq[1]):
			regs->iaoq[num - RI(iaoq[0])] = val;
			return;
	case RI(sar):	regs->sar = val;
			return;
	default:	return;
#if 0
	/* do not allow to change any of the following registers (yet) */
	case RI(sr[0]) ... RI(sr[7]):	return regs->sr[num - RI(sr[0])];
	case RI(iasq[0]):		return regs->iasq[0];
	case RI(iasq[1]):		return regs->iasq[1];
	case RI(iir):			return regs->iir;
	case RI(isr):			return regs->isr;
	case RI(ior):			return regs->ior;
	case RI(ipsw):			return regs->ipsw;
	case RI(cr27):			return regs->cr27;
        case cr0, cr24, cr25, cr26, cr27, cr28, cr29, cr30, cr31;
        case cr8, cr9, cr12, cr13, cr10, cr15;
#endif
	}
}

static int gpr_get(struct task_struct *target,
		     const struct user_regset *regset,
		     unsigned int pos, unsigned int count,
		     void *kbuf, void __user *ubuf)
{
	struct pt_regs *regs = task_regs(target);
	unsigned long *k = kbuf;
	unsigned long __user *u = ubuf;
	unsigned long reg;

	pos /= sizeof(reg);
	count /= sizeof(reg);

	if (kbuf)
		for (; count > 0 && pos < ELF_NGREG; --count)
			*k++ = get_reg(regs, pos++);
	else
		for (; count > 0 && pos < ELF_NGREG; --count)
			if (__put_user(get_reg(regs, pos++), u++))
				return -EFAULT;
	kbuf = k;
	ubuf = u;
	pos *= sizeof(reg);
	count *= sizeof(reg);
	return user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
					ELF_NGREG * sizeof(reg), -1);
}

static int gpr_set(struct task_struct *target,
		     const struct user_regset *regset,
		     unsigned int pos, unsigned int count,
		     const void *kbuf, const void __user *ubuf)
{
	struct pt_regs *regs = task_regs(target);
	const unsigned long *k = kbuf;
	const unsigned long __user *u = ubuf;
	unsigned long reg;

	pos /= sizeof(reg);
	count /= sizeof(reg);

	if (kbuf)
		for (; count > 0 && pos < ELF_NGREG; --count)
			set_reg(regs, pos++, *k++);
	else
		for (; count > 0 && pos < ELF_NGREG; --count) {
			if (__get_user(reg, u++))
				return -EFAULT;
			set_reg(regs, pos++, reg);
		}

	kbuf = k;
	ubuf = u;
	pos *= sizeof(reg);
	count *= sizeof(reg);
	return user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
					 ELF_NGREG * sizeof(reg), -1);
}

static const struct user_regset native_regsets[] = {
	[REGSET_GENERAL] = {
		.core_note_type = NT_PRSTATUS, .n = ELF_NGREG,
		.size = sizeof(long), .align = sizeof(long),
		.get = gpr_get, .set = gpr_set
	},
	[REGSET_FP] = {
		.core_note_type = NT_PRFPREG, .n = ELF_NFPREG,
		.size = sizeof(__u64), .align = sizeof(__u64),
		.get = fpr_get, .set = fpr_set
	}
};

static const struct user_regset_view user_parisc_native_view = {
	.name = "parisc", .e_machine = ELF_ARCH, .ei_osabi = ELFOSABI_LINUX,
	.regsets = native_regsets, .n = ARRAY_SIZE(native_regsets)
};

#ifdef CONFIG_64BIT
#include <linux/compat.h>

static int gpr32_get(struct task_struct *target,
		     const struct user_regset *regset,
		     unsigned int pos, unsigned int count,
		     void *kbuf, void __user *ubuf)
{
	struct pt_regs *regs = task_regs(target);
	compat_ulong_t *k = kbuf;
	compat_ulong_t __user *u = ubuf;
	compat_ulong_t reg;

	pos /= sizeof(reg);
	count /= sizeof(reg);

	if (kbuf)
		for (; count > 0 && pos < ELF_NGREG; --count)
			*k++ = get_reg(regs, pos++);
	else
		for (; count > 0 && pos < ELF_NGREG; --count)
			if (__put_user((compat_ulong_t) get_reg(regs, pos++), u++))
				return -EFAULT;

	kbuf = k;
	ubuf = u;
	pos *= sizeof(reg);
	count *= sizeof(reg);
	return user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
					ELF_NGREG * sizeof(reg), -1);
}

static int gpr32_set(struct task_struct *target,
		     const struct user_regset *regset,
		     unsigned int pos, unsigned int count,
		     const void *kbuf, const void __user *ubuf)
{
	struct pt_regs *regs = task_regs(target);
	const compat_ulong_t *k = kbuf;
	const compat_ulong_t __user *u = ubuf;
	compat_ulong_t reg;

	pos /= sizeof(reg);
	count /= sizeof(reg);

	if (kbuf)
		for (; count > 0 && pos < ELF_NGREG; --count)
			set_reg(regs, pos++, *k++);
	else
		for (; count > 0 && pos < ELF_NGREG; --count) {
			if (__get_user(reg, u++))
				return -EFAULT;
			set_reg(regs, pos++, reg);
		}

	kbuf = k;
	ubuf = u;
	pos *= sizeof(reg);
	count *= sizeof(reg);
	return user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
					 ELF_NGREG * sizeof(reg), -1);
}

/*
 * These are the regset flavors matching the 32bit native set.
 */
static const struct user_regset compat_regsets[] = {
	[REGSET_GENERAL] = {
		.core_note_type = NT_PRSTATUS, .n = ELF_NGREG,
		.size = sizeof(compat_long_t), .align = sizeof(compat_long_t),
		.get = gpr32_get, .set = gpr32_set
	},
	[REGSET_FP] = {
		.core_note_type = NT_PRFPREG, .n = ELF_NFPREG,
		.size = sizeof(__u64), .align = sizeof(__u64),
		.get = fpr_get, .set = fpr_set
	}
};

static const struct user_regset_view user_parisc_compat_view = {
	.name = "parisc", .e_machine = EM_PARISC, .ei_osabi = ELFOSABI_LINUX,
	.regsets = compat_regsets, .n = ARRAY_SIZE(compat_regsets)
};
#endif	/* CONFIG_64BIT */

const struct user_regset_view *task_user_regset_view(struct task_struct *task)
{
	BUILD_BUG_ON(sizeof(struct user_regs_struct)/sizeof(long) != ELF_NGREG);
	BUILD_BUG_ON(sizeof(struct user_fp_struct)/sizeof(__u64) != ELF_NFPREG);
#ifdef CONFIG_64BIT
	if (is_compat_task())
		return &user_parisc_compat_view;
#endif
	return &user_parisc_native_view;
}


/* HAVE_REGS_AND_STACK_ACCESS_API feature */

struct pt_regs_offset {
	const char *name;
	int offset;
};

#define REG_OFFSET_NAME(r)    {.name = #r, .offset = offsetof(struct pt_regs, r)}
#define REG_OFFSET_INDEX(r,i) {.name = #r#i, .offset = offsetof(struct pt_regs, r[i])}
#define REG_OFFSET_END {.name = NULL, .offset = 0}

static const struct pt_regs_offset regoffset_table[] = {
	REG_OFFSET_INDEX(gr,0),
	REG_OFFSET_INDEX(gr,1),
	REG_OFFSET_INDEX(gr,2),
	REG_OFFSET_INDEX(gr,3),
	REG_OFFSET_INDEX(gr,4),
	REG_OFFSET_INDEX(gr,5),
	REG_OFFSET_INDEX(gr,6),
	REG_OFFSET_INDEX(gr,7),
	REG_OFFSET_INDEX(gr,8),
	REG_OFFSET_INDEX(gr,9),
	REG_OFFSET_INDEX(gr,10),
	REG_OFFSET_INDEX(gr,11),
	REG_OFFSET_INDEX(gr,12),
	REG_OFFSET_INDEX(gr,13),
	REG_OFFSET_INDEX(gr,14),
	REG_OFFSET_INDEX(gr,15),
	REG_OFFSET_INDEX(gr,16),
	REG_OFFSET_INDEX(gr,17),
	REG_OFFSET_INDEX(gr,18),
	REG_OFFSET_INDEX(gr,19),
	REG_OFFSET_INDEX(gr,20),
	REG_OFFSET_INDEX(gr,21),
	REG_OFFSET_INDEX(gr,22),
	REG_OFFSET_INDEX(gr,23),
	REG_OFFSET_INDEX(gr,24),
	REG_OFFSET_INDEX(gr,25),
	REG_OFFSET_INDEX(gr,26),
	REG_OFFSET_INDEX(gr,27),
	REG_OFFSET_INDEX(gr,28),
	REG_OFFSET_INDEX(gr,29),
	REG_OFFSET_INDEX(gr,30),
	REG_OFFSET_INDEX(gr,31),
	REG_OFFSET_INDEX(sr,0),
	REG_OFFSET_INDEX(sr,1),
	REG_OFFSET_INDEX(sr,2),
	REG_OFFSET_INDEX(sr,3),
	REG_OFFSET_INDEX(sr,4),
	REG_OFFSET_INDEX(sr,5),
	REG_OFFSET_INDEX(sr,6),
	REG_OFFSET_INDEX(sr,7),
	REG_OFFSET_INDEX(iasq,0),
	REG_OFFSET_INDEX(iasq,1),
	REG_OFFSET_INDEX(iaoq,0),
	REG_OFFSET_INDEX(iaoq,1),
	REG_OFFSET_NAME(cr27),
	REG_OFFSET_NAME(ksp),
	REG_OFFSET_NAME(kpc),
	REG_OFFSET_NAME(sar),
	REG_OFFSET_NAME(iir),
	REG_OFFSET_NAME(isr),
	REG_OFFSET_NAME(ior),
	REG_OFFSET_NAME(ipsw),
	REG_OFFSET_END,
};

/**
 * regs_query_register_offset() - query register offset from its name
 * @name:	the name of a register
 *
 * regs_query_register_offset() returns the offset of a register in struct
 * pt_regs from its name. If the name is invalid, this returns -EINVAL;
 */
int regs_query_register_offset(const char *name)
{
	const struct pt_regs_offset *roff;
	for (roff = regoffset_table; roff->name != NULL; roff++)
		if (!strcmp(roff->name, name))
			return roff->offset;
	return -EINVAL;
}

/**
 * regs_query_register_name() - query register name from its offset
 * @offset:	the offset of a register in struct pt_regs.
 *
 * regs_query_register_name() returns the name of a register from its
 * offset in struct pt_regs. If the @offset is invalid, this returns NULL;
 */
const char *regs_query_register_name(unsigned int offset)
{
	const struct pt_regs_offset *roff;
	for (roff = regoffset_table; roff->name != NULL; roff++)
		if (roff->offset == offset)
			return roff->name;
	return NULL;
}

/**
 * regs_within_kernel_stack() - check the address in the stack
 * @regs:      pt_regs which contains kernel stack pointer.
 * @addr:      address which is checked.
 *
 * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
 * If @addr is within the kernel stack, it returns true. If not, returns false.
 */
int regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
{
	return ((addr & ~(THREAD_SIZE - 1))  ==
		(kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1)));
}

/**
 * regs_get_kernel_stack_nth() - get Nth entry of the stack
 * @regs:	pt_regs which contains kernel stack pointer.
 * @n:		stack entry number.
 *
 * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
 * is specified by @regs. If the @n th entry is NOT in the kernel stack,
 * this returns 0.
 */
unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
{
	unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);

	addr -= n;

	if (!regs_within_kernel_stack(regs, (unsigned long)addr))
		return 0;

	return *addr;
}