aboutsummaryrefslogtreecommitdiff
path: root/arch/powerpc/kernel/ptrace.c
blob: 7673e98657330dd7f90dd4d29f569d4ea2ca10e8 (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
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
/*
 *  PowerPC version
 *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
 *
 *  Derived from "arch/m68k/kernel/ptrace.c"
 *  Copyright (C) 1994 by Hamish Macdonald
 *  Taken from linux/kernel/ptrace.c and modified for M680x0.
 *  linux/kernel/ptrace.c is by Ross Biro 1/23/92, edited by Linus Torvalds
 *
 * Modified by Cort Dougan (cort@hq.fsmlabs.com)
 * and Paul Mackerras (paulus@samba.org).
 *
 * This file is subject to the terms and conditions of the GNU General
 * Public License.  See the file README.legal in the main directory of
 * this archive for more details.
 */

#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/errno.h>
#include <linux/ptrace.h>
#include <linux/regset.h>
#include <linux/elf.h>
#include <linux/user.h>
#include <linux/security.h>
#include <linux/signal.h>
#include <linux/seccomp.h>
#include <linux/audit.h>
#ifdef CONFIG_PPC32
#include <linux/module.h>
#endif

#include <asm/uaccess.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/system.h>

/*
 * does not yet catch signals sent when the child dies.
 * in exit.c or in signal.c.
 */

/*
 * Set of msr bits that gdb can change on behalf of a process.
 */
#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
#define MSR_DEBUGCHANGE	0
#else
#define MSR_DEBUGCHANGE	(MSR_SE | MSR_BE)
#endif

/*
 * Max register writeable via put_reg
 */
#ifdef CONFIG_PPC32
#define PT_MAX_PUT_REG	PT_MQ
#else
#define PT_MAX_PUT_REG	PT_CCR
#endif

static unsigned long get_user_msr(struct task_struct *task)
{
	return task->thread.regs->msr | task->thread.fpexc_mode;
}

static int set_user_msr(struct task_struct *task, unsigned long msr)
{
	task->thread.regs->msr &= ~MSR_DEBUGCHANGE;
	task->thread.regs->msr |= msr & MSR_DEBUGCHANGE;
	return 0;
}

/*
 * We prevent mucking around with the reserved area of trap
 * which are used internally by the kernel.
 */
static int set_user_trap(struct task_struct *task, unsigned long trap)
{
	task->thread.regs->trap = trap & 0xfff0;
	return 0;
}

/*
 * Get contents of register REGNO in task TASK.
 */
unsigned long ptrace_get_reg(struct task_struct *task, int regno)
{
	if (task->thread.regs == NULL)
		return -EIO;

	if (regno == PT_MSR)
		return get_user_msr(task);

	if (regno < (sizeof(struct pt_regs) / sizeof(unsigned long)))
		return ((unsigned long *)task->thread.regs)[regno];

	return -EIO;
}

/*
 * Write contents of register REGNO in task TASK.
 */
int ptrace_put_reg(struct task_struct *task, int regno, unsigned long data)
{
	if (task->thread.regs == NULL)
		return -EIO;

	if (regno == PT_MSR)
		return set_user_msr(task, data);
	if (regno == PT_TRAP)
		return set_user_trap(task, data);

	if (regno <= PT_MAX_PUT_REG) {
		((unsigned long *)task->thread.regs)[regno] = data;
		return 0;
	}
	return -EIO;
}

static int gpr_get(struct task_struct *target, const struct user_regset *regset,
		   unsigned int pos, unsigned int count,
		   void *kbuf, void __user *ubuf)
{
	int ret;

	if (target->thread.regs == NULL)
		return -EIO;

	CHECK_FULL_REGS(target->thread.regs);

	ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
				  target->thread.regs,
				  0, offsetof(struct pt_regs, msr));
	if (!ret) {
		unsigned long msr = get_user_msr(target);
		ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &msr,
					  offsetof(struct pt_regs, msr),
					  offsetof(struct pt_regs, msr) +
					  sizeof(msr));
	}

	BUILD_BUG_ON(offsetof(struct pt_regs, orig_gpr3) !=
		     offsetof(struct pt_regs, msr) + sizeof(long));

	if (!ret)
		ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
					  &target->thread.regs->orig_gpr3,
					  offsetof(struct pt_regs, orig_gpr3),
					  sizeof(struct pt_regs));
	if (!ret)
		ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
					       sizeof(struct pt_regs), -1);

	return ret;
}

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)
{
	unsigned long reg;
	int ret;

	if (target->thread.regs == NULL)
		return -EIO;

	CHECK_FULL_REGS(target->thread.regs);

	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
				 target->thread.regs,
				 0, PT_MSR * sizeof(reg));

	if (!ret && count > 0) {
		ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &reg,
					 PT_MSR * sizeof(reg),
					 (PT_MSR + 1) * sizeof(reg));
		if (!ret)
			ret = set_user_msr(target, reg);
	}

	BUILD_BUG_ON(offsetof(struct pt_regs, orig_gpr3) !=
		     offsetof(struct pt_regs, msr) + sizeof(long));

	if (!ret)
		ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
					 &target->thread.regs->orig_gpr3,
					 PT_ORIG_R3 * sizeof(reg),
					 (PT_MAX_PUT_REG + 1) * sizeof(reg));

	if (PT_MAX_PUT_REG + 1 < PT_TRAP && !ret)
		ret = user_regset_copyin_ignore(
			&pos, &count, &kbuf, &ubuf,
			(PT_MAX_PUT_REG + 1) * sizeof(reg),
			PT_TRAP * sizeof(reg));

	if (!ret && count > 0) {
		ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &reg,
					 PT_TRAP * sizeof(reg),
					 (PT_TRAP + 1) * sizeof(reg));
		if (!ret)
			ret = set_user_trap(target, reg);
	}

	if (!ret)
		ret = user_regset_copyin_ignore(
			&pos, &count, &kbuf, &ubuf,
			(PT_TRAP + 1) * sizeof(reg), -1);

	return ret;
}

static int fpr_get(struct task_struct *target, const struct user_regset *regset,
		   unsigned int pos, unsigned int count,
		   void *kbuf, void __user *ubuf)
{
	flush_fp_to_thread(target);

	BUILD_BUG_ON(offsetof(struct thread_struct, fpscr) !=
		     offsetof(struct thread_struct, fpr[32]));

	return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
				   &target->thread.fpr, 0, -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)
{
	flush_fp_to_thread(target);

	BUILD_BUG_ON(offsetof(struct thread_struct, fpscr) !=
		     offsetof(struct thread_struct, fpr[32]));

	return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
				  &target->thread.fpr, 0, -1);
}


#ifdef CONFIG_ALTIVEC
/*
 * Get/set all the altivec registers vr0..vr31, vscr, vrsave, in one go.
 * The transfer totals 34 quadword.  Quadwords 0-31 contain the
 * corresponding vector registers.  Quadword 32 contains the vscr as the
 * last word (offset 12) within that quadword.  Quadword 33 contains the
 * vrsave as the first word (offset 0) within the quadword.
 *
 * This definition of the VMX state is compatible with the current PPC32
 * ptrace interface.  This allows signal handling and ptrace to use the
 * same structures.  This also simplifies the implementation of a bi-arch
 * (combined (32- and 64-bit) gdb.
 */

static int vr_active(struct task_struct *target,
		     const struct user_regset *regset)
{
	flush_altivec_to_thread(target);
	return target->thread.used_vr ? regset->n : 0;
}

static int vr_get(struct task_struct *target, const struct user_regset *regset,
		  unsigned int pos, unsigned int count,
		  void *kbuf, void __user *ubuf)
{
	int ret;

	flush_altivec_to_thread(target);

	BUILD_BUG_ON(offsetof(struct thread_struct, vscr) !=
		     offsetof(struct thread_struct, vr[32]));

	ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
				  &target->thread.vr, 0,
				  33 * sizeof(vector128));
	if (!ret) {
		/*
		 * Copy out only the low-order word of vrsave.
		 */
		union {
			elf_vrreg_t reg;
			u32 word;
		} vrsave;
		memset(&vrsave, 0, sizeof(vrsave));
		vrsave.word = target->thread.vrsave;
		ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &vrsave,
					  33 * sizeof(vector128), -1);
	}

	return ret;
}

static int vr_set(struct task_struct *target, const struct user_regset *regset,
		  unsigned int pos, unsigned int count,
		  const void *kbuf, const void __user *ubuf)
{
	int ret;

	flush_altivec_to_thread(target);

	BUILD_BUG_ON(offsetof(struct thread_struct, vscr) !=
		     offsetof(struct thread_struct, vr[32]));

	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
				 &target->thread.vr, 0, 33 * sizeof(vector128));
	if (!ret && count > 0) {
		/*
		 * We use only the first word of vrsave.
		 */
		union {
			elf_vrreg_t reg;
			u32 word;
		} vrsave;
		memset(&vrsave, 0, sizeof(vrsave));
		vrsave.word = target->thread.vrsave;
		ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &vrsave,
					 33 * sizeof(vector128), -1);
		if (!ret)
			target->thread.vrsave = vrsave.word;
	}

	return ret;
}
#endif /* CONFIG_ALTIVEC */

#ifdef CONFIG_SPE

/*
 * For get_evrregs/set_evrregs functions 'data' has the following layout:
 *
 * struct {
 *   u32 evr[32];
 *   u64 acc;
 *   u32 spefscr;
 * }
 */

static int evr_active(struct task_struct *target,
		      const struct user_regset *regset)
{
	flush_spe_to_thread(target);
	return target->thread.used_spe ? regset->n : 0;
}

static int evr_get(struct task_struct *target, const struct user_regset *regset,
		   unsigned int pos, unsigned int count,
		   void *kbuf, void __user *ubuf)
{
	int ret;

	flush_spe_to_thread(target);

	ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
				  &target->thread.evr,
				  0, sizeof(target->thread.evr));

	BUILD_BUG_ON(offsetof(struct thread_struct, acc) + sizeof(u64) !=
		     offsetof(struct thread_struct, spefscr));

	if (!ret)
		ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
					  &target->thread.acc,
					  sizeof(target->thread.evr), -1);

	return ret;
}

static int evr_set(struct task_struct *target, const struct user_regset *regset,
		   unsigned int pos, unsigned int count,
		   const void *kbuf, const void __user *ubuf)
{
	int ret;

	flush_spe_to_thread(target);

	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
				 &target->thread.evr,
				 0, sizeof(target->thread.evr));

	BUILD_BUG_ON(offsetof(struct thread_struct, acc) + sizeof(u64) !=
		     offsetof(struct thread_struct, spefscr));

	if (!ret)
		ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
					 &target->thread.acc,
					 sizeof(target->thread.evr), -1);

	return ret;
}
#endif /* CONFIG_SPE */


/*
 * These are our native regset flavors.
 */
enum powerpc_regset {
	REGSET_GPR,
	REGSET_FPR,
#ifdef CONFIG_ALTIVEC
	REGSET_VMX,
#endif
#ifdef CONFIG_SPE
	REGSET_SPE,
#endif
};

static const struct user_regset native_regsets[] = {
	[REGSET_GPR] = {
		.core_note_type = NT_PRSTATUS, .n = ELF_NGREG,
		.size = sizeof(long), .align = sizeof(long),
		.get = gpr_get, .set = gpr_set
	},
	[REGSET_FPR] = {
		.core_note_type = NT_PRFPREG, .n = ELF_NFPREG,
		.size = sizeof(double), .align = sizeof(double),
		.get = fpr_get, .set = fpr_set
	},
#ifdef CONFIG_ALTIVEC
	[REGSET_VMX] = {
		.core_note_type = NT_PPC_VMX, .n = 34,
		.size = sizeof(vector128), .align = sizeof(vector128),
		.active = vr_active, .get = vr_get, .set = vr_set
	},
#endif
#ifdef CONFIG_SPE
	[REGSET_SPE] = {
		.n = 35,
		.size = sizeof(u32), .align = sizeof(u32),
		.active = evr_active, .get = evr_get, .set = evr_set
	},
#endif
};

static const struct user_regset_view user_ppc_native_view = {
	.name = UTS_MACHINE, .e_machine = ELF_ARCH, .ei_osabi = ELF_OSABI,
	.regsets = native_regsets, .n = ARRAY_SIZE(native_regsets)
};

#ifdef CONFIG_PPC64
#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)
{
	const unsigned long *regs = &target->thread.regs->gpr[0];
	compat_ulong_t *k = kbuf;
	compat_ulong_t __user *u = ubuf;
	compat_ulong_t reg;

	if (target->thread.regs == NULL)
		return -EIO;

	CHECK_FULL_REGS(target->thread.regs);

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

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

	if (count > 0 && pos == PT_MSR) {
		reg = get_user_msr(target);
		if (kbuf)
			*k++ = reg;
		else if (__put_user(reg, u++))
			return -EFAULT;
		++pos;
		--count;
	}

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

	kbuf = k;
	ubuf = u;
	pos *= sizeof(reg);
	count *= sizeof(reg);
	return user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
					PT_REGS_COUNT * 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)
{
	unsigned long *regs = &target->thread.regs->gpr[0];
	const compat_ulong_t *k = kbuf;
	const compat_ulong_t __user *u = ubuf;
	compat_ulong_t reg;

	if (target->thread.regs == NULL)
		return -EIO;

	CHECK_FULL_REGS(target->thread.regs);

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

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


	if (count > 0 && pos == PT_MSR) {
		if (kbuf)
			reg = *k++;
		else if (__get_user(reg, u++))
			return -EFAULT;
		set_user_msr(target, reg);
		++pos;
		--count;
	}

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

	if (count > 0 && pos == PT_TRAP) {
		if (kbuf)
			reg = *k++;
		else if (__get_user(reg, u++))
			return -EFAULT;
		set_user_trap(target, reg);
		++pos;
		--count;
	}

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

/*
 * These are the regset flavors matching the CONFIG_PPC32 native set.
 */
static const struct user_regset compat_regsets[] = {
	[REGSET_GPR] = {
		.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_FPR] = {
		.core_note_type = NT_PRFPREG, .n = ELF_NFPREG,
		.size = sizeof(double), .align = sizeof(double),
		.get = fpr_get, .set = fpr_set
	},
#ifdef CONFIG_ALTIVEC
	[REGSET_VMX] = {
		.core_note_type = NT_PPC_VMX, .n = 34,
		.size = sizeof(vector128), .align = sizeof(vector128),
		.active = vr_active, .get = vr_get, .set = vr_set
	},
#endif
#ifdef CONFIG_SPE
	[REGSET_SPE] = {
		.core_note_type = NT_PPC_SPE, .n = 35,
		.size = sizeof(u32), .align = sizeof(u32),
		.active = evr_active, .get = evr_get, .set = evr_set
	},
#endif
};

static const struct user_regset_view user_ppc_compat_view = {
	.name = "ppc", .e_machine = EM_PPC, .ei_osabi = ELF_OSABI,
	.regsets = compat_regsets, .n = ARRAY_SIZE(compat_regsets)
};
#endif	/* CONFIG_PPC64 */

const struct user_regset_view *task_user_regset_view(struct task_struct *task)
{
#ifdef CONFIG_PPC64
	if (test_tsk_thread_flag(task, TIF_32BIT))
		return &user_ppc_compat_view;
#endif
	return &user_ppc_native_view;
}


void user_enable_single_step(struct task_struct *task)
{
	struct pt_regs *regs = task->thread.regs;

	if (regs != NULL) {
#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
		task->thread.dbcr0 = DBCR0_IDM | DBCR0_IC;
		regs->msr |= MSR_DE;
#else
		regs->msr |= MSR_SE;
#endif
	}
	set_tsk_thread_flag(task, TIF_SINGLESTEP);
}

void user_disable_single_step(struct task_struct *task)
{
	struct pt_regs *regs = task->thread.regs;

	if (regs != NULL) {
#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
		task->thread.dbcr0 = 0;
		regs->msr &= ~MSR_DE;
#else
		regs->msr &= ~MSR_SE;
#endif
	}
	clear_tsk_thread_flag(task, TIF_SINGLESTEP);
}

static int ptrace_set_debugreg(struct task_struct *task, unsigned long addr,
			       unsigned long data)
{
	/* We only support one DABR and no IABRS at the moment */
	if (addr > 0)
		return -EINVAL;

	/* The bottom 3 bits are flags */
	if ((data & ~0x7UL) >= TASK_SIZE)
		return -EIO;

	/* Ensure translation is on */
	if (data && !(data & DABR_TRANSLATION))
		return -EIO;

	task->thread.dabr = data;
	return 0;
}

/*
 * Called by kernel/ptrace.c when detaching..
 *
 * Make sure single step bits etc are not set.
 */
void ptrace_disable(struct task_struct *child)
{
	/* make sure the single step bit is not set. */
	user_disable_single_step(child);
}

/*
 * Here are the old "legacy" powerpc specific getregs/setregs ptrace calls,
 * we mark them as obsolete now, they will be removed in a future version
 */
static long arch_ptrace_old(struct task_struct *child, long request, long addr,
			    long data)
{
	switch (request) {
	case PPC_PTRACE_GETREGS:	/* Get GPRs 0 - 31. */
		return copy_regset_to_user(child, &user_ppc_native_view,
					   REGSET_GPR, 0, 32 * sizeof(long),
					   (void __user *) data);

	case PPC_PTRACE_SETREGS:	/* Set GPRs 0 - 31. */
		return copy_regset_from_user(child, &user_ppc_native_view,
					     REGSET_GPR, 0, 32 * sizeof(long),
					     (const void __user *) data);

	case PPC_PTRACE_GETFPREGS:	/* Get FPRs 0 - 31. */
		return copy_regset_to_user(child, &user_ppc_native_view,
					   REGSET_FPR, 0, 32 * sizeof(double),
					   (void __user *) data);

	case PPC_PTRACE_SETFPREGS:	/* Set FPRs 0 - 31. */
		return copy_regset_from_user(child, &user_ppc_native_view,
					     REGSET_FPR, 0, 32 * sizeof(double),
					     (const void __user *) data);
	}

	return -EPERM;
}

long arch_ptrace(struct task_struct *child, long request, long addr, long data)
{
	int ret = -EPERM;

	switch (request) {
	/* read the word at location addr in the USER area. */
	case PTRACE_PEEKUSR: {
		unsigned long index, tmp;

		ret = -EIO;
		/* convert to index and check */
#ifdef CONFIG_PPC32
		index = (unsigned long) addr >> 2;
		if ((addr & 3) || (index > PT_FPSCR)
		    || (child->thread.regs == NULL))
#else
		index = (unsigned long) addr >> 3;
		if ((addr & 7) || (index > PT_FPSCR))
#endif
			break;

		CHECK_FULL_REGS(child->thread.regs);
		if (index < PT_FPR0) {
			tmp = ptrace_get_reg(child, (int) index);
		} else {
			flush_fp_to_thread(child);
			tmp = ((unsigned long *)child->thread.fpr)[index - PT_FPR0];
		}
		ret = put_user(tmp,(unsigned long __user *) data);
		break;
	}

	/* write the word at location addr in the USER area */
	case PTRACE_POKEUSR: {
		unsigned long index;

		ret = -EIO;
		/* convert to index and check */
#ifdef CONFIG_PPC32
		index = (unsigned long) addr >> 2;
		if ((addr & 3) || (index > PT_FPSCR)
		    || (child->thread.regs == NULL))
#else
		index = (unsigned long) addr >> 3;
		if ((addr & 7) || (index > PT_FPSCR))
#endif
			break;

		CHECK_FULL_REGS(child->thread.regs);
		if (index < PT_FPR0) {
			ret = ptrace_put_reg(child, index, data);
		} else {
			flush_fp_to_thread(child);
			((unsigned long *)child->thread.fpr)[index - PT_FPR0] = data;
			ret = 0;
		}
		break;
	}

	case PTRACE_GET_DEBUGREG: {
		ret = -EINVAL;
		/* We only support one DABR and no IABRS at the moment */
		if (addr > 0)
			break;
		ret = put_user(child->thread.dabr,
			       (unsigned long __user *)data);
		break;
	}

	case PTRACE_SET_DEBUGREG:
		ret = ptrace_set_debugreg(child, addr, data);
		break;

#ifdef CONFIG_PPC64
	case PTRACE_GETREGS64:
#endif
	case PTRACE_GETREGS:	/* Get all pt_regs from the child. */
		return copy_regset_to_user(child, &user_ppc_native_view,
					   REGSET_GPR,
					   0, sizeof(struct pt_regs),
					   (void __user *) data);

#ifdef CONFIG_PPC64
	case PTRACE_SETREGS64:
#endif
	case PTRACE_SETREGS:	/* Set all gp regs in the child. */
		return copy_regset_from_user(child, &user_ppc_native_view,
					     REGSET_GPR,
					     0, sizeof(struct pt_regs),
					     (const void __user *) data);

	case PTRACE_GETFPREGS: /* Get the child FPU state (FPR0...31 + FPSCR) */
		return copy_regset_to_user(child, &user_ppc_native_view,
					   REGSET_FPR,
					   0, sizeof(elf_fpregset_t),
					   (void __user *) data);

	case PTRACE_SETFPREGS: /* Set the child FPU state (FPR0...31 + FPSCR) */
		return copy_regset_from_user(child, &user_ppc_native_view,
					     REGSET_FPR,
					     0, sizeof(elf_fpregset_t),
					     (const void __user *) data);

#ifdef CONFIG_ALTIVEC
	case PTRACE_GETVRREGS:
		return copy_regset_to_user(child, &user_ppc_native_view,
					   REGSET_VMX,
					   0, (33 * sizeof(vector128) +
					       sizeof(u32)),
					   (void __user *) data);

	case PTRACE_SETVRREGS:
		return copy_regset_from_user(child, &user_ppc_native_view,
					     REGSET_VMX,
					     0, (33 * sizeof(vector128) +
						 sizeof(u32)),
					     (const void __user *) data);
#endif
#ifdef CONFIG_SPE
	case PTRACE_GETEVRREGS:
		/* Get the child spe register state. */
		return copy_regset_to_user(child, &user_ppc_native_view,
					   REGSET_SPE, 0, 35 * sizeof(u32),
					   (void __user *) data);

	case PTRACE_SETEVRREGS:
		/* Set the child spe register state. */
		return copy_regset_from_user(child, &user_ppc_native_view,
					     REGSET_SPE, 0, 35 * sizeof(u32),
					     (const void __user *) data);
#endif

	/* Old reverse args ptrace callss */
	case PPC_PTRACE_GETREGS: /* Get GPRs 0 - 31. */
	case PPC_PTRACE_SETREGS: /* Set GPRs 0 - 31. */
	case PPC_PTRACE_GETFPREGS: /* Get FPRs 0 - 31. */
	case PPC_PTRACE_SETFPREGS: /* Get FPRs 0 - 31. */
		ret = arch_ptrace_old(child, request, addr, data);
		break;

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

static void do_syscall_trace(void)
{
	/* the 0x80 provides a way for the tracing parent to distinguish
	   between a syscall stop and SIGTRAP delivery */
	ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
				 ? 0x80 : 0));

	/*
	 * this isn't the same as continuing with a signal, but it will do
	 * for normal use.  strace only continues with a signal if the
	 * stopping signal is not SIGTRAP.  -brl
	 */
	if (current->exit_code) {
		send_sig(current->exit_code, current, 1);
		current->exit_code = 0;
	}
}

void do_syscall_trace_enter(struct pt_regs *regs)
{
	secure_computing(regs->gpr[0]);

	if (test_thread_flag(TIF_SYSCALL_TRACE)
	    && (current->ptrace & PT_PTRACED))
		do_syscall_trace();

	if (unlikely(current->audit_context)) {
#ifdef CONFIG_PPC64
		if (!test_thread_flag(TIF_32BIT))
			audit_syscall_entry(AUDIT_ARCH_PPC64,
					    regs->gpr[0],
					    regs->gpr[3], regs->gpr[4],
					    regs->gpr[5], regs->gpr[6]);
		else
#endif
			audit_syscall_entry(AUDIT_ARCH_PPC,
					    regs->gpr[0],
					    regs->gpr[3] & 0xffffffff,
					    regs->gpr[4] & 0xffffffff,
					    regs->gpr[5] & 0xffffffff,
					    regs->gpr[6] & 0xffffffff);
	}
}

void do_syscall_trace_leave(struct pt_regs *regs)
{
	if (unlikely(current->audit_context))
		audit_syscall_exit((regs->ccr&0x10000000)?AUDITSC_FAILURE:AUDITSC_SUCCESS,
				   regs->result);

	if ((test_thread_flag(TIF_SYSCALL_TRACE)
	     || test_thread_flag(TIF_SINGLESTEP))
	    && (current->ptrace & PT_PTRACED))
		do_syscall_trace();
}