summaryrefslogtreecommitdiffstats
path: root/arch/s390/kernel/ptrace.c
blob: 7cf46423441940a975de0c60cdbca6a736018921 (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
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
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
/*
 *  arch/s390/kernel/ptrace.c
 *
 *  S390 version
 *    Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation
 *    Author(s): Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com),
 *               Martin Schwidefsky (schwidefsky@de.ibm.com)
 *
 *  Based on 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@cs.nmt.edu) 
 *
 *
 * 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/user.h>
#include <linux/security.h>
#include <linux/audit.h>
#include <linux/signal.h>
#include <linux/elf.h>
#include <linux/regset.h>
#include <linux/tracehook.h>
#include <linux/seccomp.h>
#include <trace/syscall.h>
#include <asm/compat.h>
#include <asm/segment.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include <asm/unistd.h>
#include "entry.h"

#ifdef CONFIG_COMPAT
#include "compat_ptrace.h"
#endif

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

enum s390_regset {
	REGSET_GENERAL,
	REGSET_FP,
	REGSET_GENERAL_EXTENDED,
};

static void
FixPerRegisters(struct task_struct *task)
{
	struct pt_regs *regs;
	per_struct *per_info;
	per_cr_words cr_words;

	regs = task_pt_regs(task);
	per_info = (per_struct *) &task->thread.per_info;
	per_info->control_regs.bits.em_instruction_fetch =
		per_info->single_step | per_info->instruction_fetch;
	
	if (per_info->single_step) {
		per_info->control_regs.bits.starting_addr = 0;
#ifdef CONFIG_COMPAT
		if (is_compat_task())
			per_info->control_regs.bits.ending_addr = 0x7fffffffUL;
		else
#endif
			per_info->control_regs.bits.ending_addr = PSW_ADDR_INSN;
	} else {
		per_info->control_regs.bits.starting_addr =
			per_info->starting_addr;
		per_info->control_regs.bits.ending_addr =
			per_info->ending_addr;
	}
	/*
	 * if any of the control reg tracing bits are on 
	 * we switch on per in the psw
	 */
	if (per_info->control_regs.words.cr[0] & PER_EM_MASK)
		regs->psw.mask |= PSW_MASK_PER;
	else
		regs->psw.mask &= ~PSW_MASK_PER;

	if (per_info->control_regs.bits.em_storage_alteration)
		per_info->control_regs.bits.storage_alt_space_ctl = 1;
	else
		per_info->control_regs.bits.storage_alt_space_ctl = 0;

	if (task == current) {
		__ctl_store(cr_words, 9, 11);
		if (memcmp(&cr_words, &per_info->control_regs.words,
			   sizeof(cr_words)) != 0)
			__ctl_load(per_info->control_regs.words, 9, 11);
	}
}

void user_enable_single_step(struct task_struct *task)
{
	task->thread.per_info.single_step = 1;
	FixPerRegisters(task);
}

void user_disable_single_step(struct task_struct *task)
{
	task->thread.per_info.single_step = 0;
	FixPerRegisters(task);
}

/*
 * 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);
}

#ifndef CONFIG_64BIT
# define __ADDR_MASK 3
#else
# define __ADDR_MASK 7
#endif

/*
 * Read the word at offset addr from the user area of a process. The
 * trouble here is that the information is littered over different
 * locations. The process registers are found on the kernel stack,
 * the floating point stuff and the trace settings are stored in
 * the task structure. In addition the different structures in
 * struct user contain pad bytes that should be read as zeroes.
 * Lovely...
 */
static unsigned long __peek_user(struct task_struct *child, addr_t addr)
{
	struct user *dummy = NULL;
	addr_t offset, tmp;

	if (addr < (addr_t) &dummy->regs.acrs) {
		/*
		 * psw and gprs are stored on the stack
		 */
		tmp = *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr);
		if (addr == (addr_t) &dummy->regs.psw.mask)
			/* Remove per bit from user psw. */
			tmp &= ~PSW_MASK_PER;

	} else if (addr < (addr_t) &dummy->regs.orig_gpr2) {
		/*
		 * access registers are stored in the thread structure
		 */
		offset = addr - (addr_t) &dummy->regs.acrs;
#ifdef CONFIG_64BIT
		/*
		 * Very special case: old & broken 64 bit gdb reading
		 * from acrs[15]. Result is a 64 bit value. Read the
		 * 32 bit acrs[15] value and shift it by 32. Sick...
		 */
		if (addr == (addr_t) &dummy->regs.acrs[15])
			tmp = ((unsigned long) child->thread.acrs[15]) << 32;
		else
#endif
		tmp = *(addr_t *)((addr_t) &child->thread.acrs + offset);

	} else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
		/*
		 * orig_gpr2 is stored on the kernel stack
		 */
		tmp = (addr_t) task_pt_regs(child)->orig_gpr2;

	} else if (addr < (addr_t) &dummy->regs.fp_regs) {
		/*
		 * prevent reads of padding hole between
		 * orig_gpr2 and fp_regs on s390.
		 */
		tmp = 0;

	} else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
		/* 
		 * floating point regs. are stored in the thread structure
		 */
		offset = addr - (addr_t) &dummy->regs.fp_regs;
		tmp = *(addr_t *)((addr_t) &child->thread.fp_regs + offset);
		if (addr == (addr_t) &dummy->regs.fp_regs.fpc)
			tmp &= (unsigned long) FPC_VALID_MASK
				<< (BITS_PER_LONG - 32);

	} else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
		/*
		 * per_info is found in the thread structure
		 */
		offset = addr - (addr_t) &dummy->regs.per_info;
		tmp = *(addr_t *)((addr_t) &child->thread.per_info + offset);

	} else
		tmp = 0;

	return tmp;
}

static int
peek_user(struct task_struct *child, addr_t addr, addr_t data)
{
	addr_t tmp, mask;

	/*
	 * Stupid gdb peeks/pokes the access registers in 64 bit with
	 * an alignment of 4. Programmers from hell...
	 */
	mask = __ADDR_MASK;
#ifdef CONFIG_64BIT
	if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
	    addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
		mask = 3;
#endif
	if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
		return -EIO;

	tmp = __peek_user(child, addr);
	return put_user(tmp, (addr_t __user *) data);
}

/*
 * Write a word to the user area of a process at location addr. This
 * operation does have an additional problem compared to peek_user.
 * Stores to the program status word and on the floating point
 * control register needs to get checked for validity.
 */
static int __poke_user(struct task_struct *child, addr_t addr, addr_t data)
{
	struct user *dummy = NULL;
	addr_t offset;

	if (addr < (addr_t) &dummy->regs.acrs) {
		/*
		 * psw and gprs are stored on the stack
		 */
		if (addr == (addr_t) &dummy->regs.psw.mask &&
#ifdef CONFIG_COMPAT
		    data != PSW_MASK_MERGE(psw_user32_bits, data) &&
#endif
		    data != PSW_MASK_MERGE(psw_user_bits, data))
			/* Invalid psw mask. */
			return -EINVAL;
#ifndef CONFIG_64BIT
		if (addr == (addr_t) &dummy->regs.psw.addr)
			/* I'd like to reject addresses without the
			   high order bit but older gdb's rely on it */
			data |= PSW_ADDR_AMODE;
#endif
		*(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr) = data;

	} else if (addr < (addr_t) (&dummy->regs.orig_gpr2)) {
		/*
		 * access registers are stored in the thread structure
		 */
		offset = addr - (addr_t) &dummy->regs.acrs;
#ifdef CONFIG_64BIT
		/*
		 * Very special case: old & broken 64 bit gdb writing
		 * to acrs[15] with a 64 bit value. Ignore the lower
		 * half of the value and write the upper 32 bit to
		 * acrs[15]. Sick...
		 */
		if (addr == (addr_t) &dummy->regs.acrs[15])
			child->thread.acrs[15] = (unsigned int) (data >> 32);
		else
#endif
		*(addr_t *)((addr_t) &child->thread.acrs + offset) = data;

	} else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
		/*
		 * orig_gpr2 is stored on the kernel stack
		 */
		task_pt_regs(child)->orig_gpr2 = data;

	} else if (addr < (addr_t) &dummy->regs.fp_regs) {
		/*
		 * prevent writes of padding hole between
		 * orig_gpr2 and fp_regs on s390.
		 */
		return 0;

	} else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
		/*
		 * floating point regs. are stored in the thread structure
		 */
		if (addr == (addr_t) &dummy->regs.fp_regs.fpc &&
		    (data & ~((unsigned long) FPC_VALID_MASK
			      << (BITS_PER_LONG - 32))) != 0)
			return -EINVAL;
		offset = addr - (addr_t) &dummy->regs.fp_regs;
		*(addr_t *)((addr_t) &child->thread.fp_regs + offset) = data;

	} else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
		/*
		 * per_info is found in the thread structure 
		 */
		offset = addr - (addr_t) &dummy->regs.per_info;
		*(addr_t *)((addr_t) &child->thread.per_info + offset) = data;

	}

	FixPerRegisters(child);
	return 0;
}

static int
poke_user(struct task_struct *child, addr_t addr, addr_t data)
{
	addr_t mask;

	/*
	 * Stupid gdb peeks/pokes the access registers in 64 bit with
	 * an alignment of 4. Programmers from hell indeed...
	 */
	mask = __ADDR_MASK;
#ifdef CONFIG_64BIT
	if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
	    addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
		mask = 3;
#endif
	if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
		return -EIO;

	return __poke_user(child, addr, data);
}

long arch_ptrace(struct task_struct *child, long request, long addr, long data)
{
	ptrace_area parea; 
	int copied, ret;

	switch (request) {
	case PTRACE_PEEKUSR:
		/* read the word at location addr in the USER area. */
		return peek_user(child, addr, data);

	case PTRACE_POKEUSR:
		/* write the word at location addr in the USER area */
		return poke_user(child, addr, data);

	case PTRACE_PEEKUSR_AREA:
	case PTRACE_POKEUSR_AREA:
		if (copy_from_user(&parea, (void __force __user *) addr,
							sizeof(parea)))
			return -EFAULT;
		addr = parea.kernel_addr;
		data = parea.process_addr;
		copied = 0;
		while (copied < parea.len) {
			if (request == PTRACE_PEEKUSR_AREA)
				ret = peek_user(child, addr, data);
			else {
				addr_t utmp;
				if (get_user(utmp,
					     (addr_t __force __user *) data))
					return -EFAULT;
				ret = poke_user(child, addr, utmp);
			}
			if (ret)
				return ret;
			addr += sizeof(unsigned long);
			data += sizeof(unsigned long);
			copied += sizeof(unsigned long);
		}
		return 0;
	default:
		/* Removing high order bit from addr (only for 31 bit). */
		addr &= PSW_ADDR_INSN;
		return ptrace_request(child, request, addr, data);
	}
}

#ifdef CONFIG_COMPAT
/*
 * Now the fun part starts... a 31 bit program running in the
 * 31 bit emulation tracing another program. PTRACE_PEEKTEXT,
 * PTRACE_PEEKDATA, PTRACE_POKETEXT and PTRACE_POKEDATA are easy
 * to handle, the difference to the 64 bit versions of the requests
 * is that the access is done in multiples of 4 byte instead of
 * 8 bytes (sizeof(unsigned long) on 31/64 bit).
 * The ugly part are PTRACE_PEEKUSR, PTRACE_PEEKUSR_AREA,
 * PTRACE_POKEUSR and PTRACE_POKEUSR_AREA. If the traced program
 * is a 31 bit program too, the content of struct user can be
 * emulated. A 31 bit program peeking into the struct user of
 * a 64 bit program is a no-no.
 */

/*
 * Same as peek_user but for a 31 bit program.
 */
static u32 __peek_user_compat(struct task_struct *child, addr_t addr)
{
	struct user32 *dummy32 = NULL;
	per_struct32 *dummy_per32 = NULL;
	addr_t offset;
	__u32 tmp;

	if (addr < (addr_t) &dummy32->regs.acrs) {
		/*
		 * psw and gprs are stored on the stack
		 */
		if (addr == (addr_t) &dummy32->regs.psw.mask) {
			/* Fake a 31 bit psw mask. */
			tmp = (__u32)(task_pt_regs(child)->psw.mask >> 32);
			tmp = PSW32_MASK_MERGE(psw32_user_bits, tmp);
		} else if (addr == (addr_t) &dummy32->regs.psw.addr) {
			/* Fake a 31 bit psw address. */
			tmp = (__u32) task_pt_regs(child)->psw.addr |
				PSW32_ADDR_AMODE31;
		} else {
			/* gpr 0-15 */
			tmp = *(__u32 *)((addr_t) &task_pt_regs(child)->psw +
					 addr*2 + 4);
		}
	} else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
		/*
		 * access registers are stored in the thread structure
		 */
		offset = addr - (addr_t) &dummy32->regs.acrs;
		tmp = *(__u32*)((addr_t) &child->thread.acrs + offset);

	} else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
		/*
		 * orig_gpr2 is stored on the kernel stack
		 */
		tmp = *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4);

	} else if (addr < (addr_t) &dummy32->regs.fp_regs) {
		/*
		 * prevent reads of padding hole between
		 * orig_gpr2 and fp_regs on s390.
		 */
		tmp = 0;

	} else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
		/*
		 * floating point regs. are stored in the thread structure 
		 */
	        offset = addr - (addr_t) &dummy32->regs.fp_regs;
		tmp = *(__u32 *)((addr_t) &child->thread.fp_regs + offset);

	} else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
		/*
		 * per_info is found in the thread structure
		 */
		offset = addr - (addr_t) &dummy32->regs.per_info;
		/* This is magic. See per_struct and per_struct32. */
		if ((offset >= (addr_t) &dummy_per32->control_regs &&
		     offset < (addr_t) (&dummy_per32->control_regs + 1)) ||
		    (offset >= (addr_t) &dummy_per32->starting_addr &&
		     offset <= (addr_t) &dummy_per32->ending_addr) ||
		    offset == (addr_t) &dummy_per32->lowcore.words.address)
			offset = offset*2 + 4;
		else
			offset = offset*2;
		tmp = *(__u32 *)((addr_t) &child->thread.per_info + offset);

	} else
		tmp = 0;

	return tmp;
}

static int peek_user_compat(struct task_struct *child,
			    addr_t addr, addr_t data)
{
	__u32 tmp;

	if (!is_compat_task() || (addr & 3) || addr > sizeof(struct user) - 3)
		return -EIO;

	tmp = __peek_user_compat(child, addr);
	return put_user(tmp, (__u32 __user *) data);
}

/*
 * Same as poke_user but for a 31 bit program.
 */
static int __poke_user_compat(struct task_struct *child,
			      addr_t addr, addr_t data)
{
	struct user32 *dummy32 = NULL;
	per_struct32 *dummy_per32 = NULL;
	__u32 tmp = (__u32) data;
	addr_t offset;

	if (addr < (addr_t) &dummy32->regs.acrs) {
		/*
		 * psw, gprs, acrs and orig_gpr2 are stored on the stack
		 */
		if (addr == (addr_t) &dummy32->regs.psw.mask) {
			/* Build a 64 bit psw mask from 31 bit mask. */
			if (tmp != PSW32_MASK_MERGE(psw32_user_bits, tmp))
				/* Invalid psw mask. */
				return -EINVAL;
			task_pt_regs(child)->psw.mask =
				PSW_MASK_MERGE(psw_user32_bits, (__u64) tmp << 32);
		} else if (addr == (addr_t) &dummy32->regs.psw.addr) {
			/* Build a 64 bit psw address from 31 bit address. */
			task_pt_regs(child)->psw.addr =
				(__u64) tmp & PSW32_ADDR_INSN;
		} else {
			/* gpr 0-15 */
			*(__u32*)((addr_t) &task_pt_regs(child)->psw
				  + addr*2 + 4) = tmp;
		}
	} else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
		/*
		 * access registers are stored in the thread structure
		 */
		offset = addr - (addr_t) &dummy32->regs.acrs;
		*(__u32*)((addr_t) &child->thread.acrs + offset) = tmp;

	} else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
		/*
		 * orig_gpr2 is stored on the kernel stack
		 */
		*(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4) = tmp;

	} else if (addr < (addr_t) &dummy32->regs.fp_regs) {
		/*
		 * prevent writess of padding hole between
		 * orig_gpr2 and fp_regs on s390.
		 */
		return 0;

	} else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
		/*
		 * floating point regs. are stored in the thread structure 
		 */
		if (addr == (addr_t) &dummy32->regs.fp_regs.fpc &&
		    (tmp & ~FPC_VALID_MASK) != 0)
			/* Invalid floating point control. */
			return -EINVAL;
	        offset = addr - (addr_t) &dummy32->regs.fp_regs;
		*(__u32 *)((addr_t) &child->thread.fp_regs + offset) = tmp;

	} else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
		/*
		 * per_info is found in the thread structure.
		 */
		offset = addr - (addr_t) &dummy32->regs.per_info;
		/*
		 * This is magic. See per_struct and per_struct32.
		 * By incident the offsets in per_struct are exactly
		 * twice the offsets in per_struct32 for all fields.
		 * The 8 byte fields need special handling though,
		 * because the second half (bytes 4-7) is needed and
		 * not the first half.
		 */
		if ((offset >= (addr_t) &dummy_per32->control_regs &&
		     offset < (addr_t) (&dummy_per32->control_regs + 1)) ||
		    (offset >= (addr_t) &dummy_per32->starting_addr &&
		     offset <= (addr_t) &dummy_per32->ending_addr) ||
		    offset == (addr_t) &dummy_per32->lowcore.words.address)
			offset = offset*2 + 4;
		else
			offset = offset*2;
		*(__u32 *)((addr_t) &child->thread.per_info + offset) = tmp;

	}

	FixPerRegisters(child);
	return 0;
}

static int poke_user_compat(struct task_struct *child,
			    addr_t addr, addr_t data)
{
	if (!is_compat_task() || (addr & 3) || addr > sizeof(struct user32) - 3)
		return -EIO;

	return __poke_user_compat(child, addr, data);
}

long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
			compat_ulong_t caddr, compat_ulong_t cdata)
{
	unsigned long addr = caddr;
	unsigned long data = cdata;
	ptrace_area_emu31 parea; 
	int copied, ret;

	switch (request) {
	case PTRACE_PEEKUSR:
		/* read the word at location addr in the USER area. */
		return peek_user_compat(child, addr, data);

	case PTRACE_POKEUSR:
		/* write the word at location addr in the USER area */
		return poke_user_compat(child, addr, data);

	case PTRACE_PEEKUSR_AREA:
	case PTRACE_POKEUSR_AREA:
		if (copy_from_user(&parea, (void __force __user *) addr,
							sizeof(parea)))
			return -EFAULT;
		addr = parea.kernel_addr;
		data = parea.process_addr;
		copied = 0;
		while (copied < parea.len) {
			if (request == PTRACE_PEEKUSR_AREA)
				ret = peek_user_compat(child, addr, data);
			else {
				__u32 utmp;
				if (get_user(utmp,
					     (__u32 __force __user *) data))
					return -EFAULT;
				ret = poke_user_compat(child, addr, utmp);
			}
			if (ret)
				return ret;
			addr += sizeof(unsigned int);
			data += sizeof(unsigned int);
			copied += sizeof(unsigned int);
		}
		return 0;
	}
	return compat_ptrace_request(child, request, addr, data);
}
#endif

asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
{
	long ret;

	/* Do the secure computing check first. */
	secure_computing(regs->gprs[2]);

	/*
	 * The sysc_tracesys code in entry.S stored the system
	 * call number to gprs[2].
	 */
	ret = regs->gprs[2];
	if (test_thread_flag(TIF_SYSCALL_TRACE) &&
	    (tracehook_report_syscall_entry(regs) ||
	     regs->gprs[2] >= NR_syscalls)) {
		/*
		 * Tracing decided this syscall should not happen or the
		 * debugger stored an invalid system call number. Skip
		 * the system call and the system call restart handling.
		 */
		regs->svcnr = 0;
		ret = -1;
	}

	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
		trace_sys_enter(regs, regs->gprs[2]);

	if (unlikely(current->audit_context))
		audit_syscall_entry(is_compat_task() ?
					AUDIT_ARCH_S390 : AUDIT_ARCH_S390X,
				    regs->gprs[2], regs->orig_gpr2,
				    regs->gprs[3], regs->gprs[4],
				    regs->gprs[5]);
	return ret;
}

asmlinkage void do_syscall_trace_exit(struct pt_regs *regs)
{
	if (unlikely(current->audit_context))
		audit_syscall_exit(AUDITSC_RESULT(regs->gprs[2]),
				   regs->gprs[2]);

	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
		trace_sys_exit(regs, regs->gprs[2]);

	if (test_thread_flag(TIF_SYSCALL_TRACE))
		tracehook_report_syscall_exit(regs, 0);
}

/*
 * user_regset definitions.
 */

static int s390_regs_get(struct task_struct *target,
			 const struct user_regset *regset,
			 unsigned int pos, unsigned int count,
			 void *kbuf, void __user *ubuf)
{
	if (target == current)
		save_access_regs(target->thread.acrs);

	if (kbuf) {
		unsigned long *k = kbuf;
		while (count > 0) {
			*k++ = __peek_user(target, pos);
			count -= sizeof(*k);
			pos += sizeof(*k);
		}
	} else {
		unsigned long __user *u = ubuf;
		while (count > 0) {
			if (__put_user(__peek_user(target, pos), u++))
				return -EFAULT;
			count -= sizeof(*u);
			pos += sizeof(*u);
		}
	}
	return 0;
}

static int s390_regs_set(struct task_struct *target,
			 const struct user_regset *regset,
			 unsigned int pos, unsigned int count,
			 const void *kbuf, const void __user *ubuf)
{
	int rc = 0;

	if (target == current)
		save_access_regs(target->thread.acrs);

	if (kbuf) {
		const unsigned long *k = kbuf;
		while (count > 0 && !rc) {
			rc = __poke_user(target, pos, *k++);
			count -= sizeof(*k);
			pos += sizeof(*k);
		}
	} else {
		const unsigned long  __user *u = ubuf;
		while (count > 0 && !rc) {
			unsigned long word;
			rc = __get_user(word, u++);
			if (rc)
				break;
			rc = __poke_user(target, pos, word);
			count -= sizeof(*u);
			pos += sizeof(*u);
		}
	}

	if (rc == 0 && target == current)
		restore_access_regs(target->thread.acrs);

	return rc;
}

static int s390_fpregs_get(struct task_struct *target,
			   const struct user_regset *regset, unsigned int pos,
			   unsigned int count, void *kbuf, void __user *ubuf)
{
	if (target == current)
		save_fp_regs(&target->thread.fp_regs);

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

static int s390_fpregs_set(struct task_struct *target,
			   const struct user_regset *regset, unsigned int pos,
			   unsigned int count, const void *kbuf,
			   const void __user *ubuf)
{
	int rc = 0;

	if (target == current)
		save_fp_regs(&target->thread.fp_regs);

	/* If setting FPC, must validate it first. */
	if (count > 0 && pos < offsetof(s390_fp_regs, fprs)) {
		u32 fpc[2] = { target->thread.fp_regs.fpc, 0 };
		rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &fpc,
					0, offsetof(s390_fp_regs, fprs));
		if (rc)
			return rc;
		if ((fpc[0] & ~FPC_VALID_MASK) != 0 || fpc[1] != 0)
			return -EINVAL;
		target->thread.fp_regs.fpc = fpc[0];
	}

	if (rc == 0 && count > 0)
		rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
					target->thread.fp_regs.fprs,
					offsetof(s390_fp_regs, fprs), -1);

	if (rc == 0 && target == current)
		restore_fp_regs(&target->thread.fp_regs);

	return rc;
}

static const struct user_regset s390_regsets[] = {
	[REGSET_GENERAL] = {
		.core_note_type = NT_PRSTATUS,
		.n = sizeof(s390_regs) / sizeof(long),
		.size = sizeof(long),
		.align = sizeof(long),
		.get = s390_regs_get,
		.set = s390_regs_set,
	},
	[REGSET_FP] = {
		.core_note_type = NT_PRFPREG,
		.n = sizeof(s390_fp_regs) / sizeof(long),
		.size = sizeof(long),
		.align = sizeof(long),
		.get = s390_fpregs_get,
		.set = s390_fpregs_set,
	},
};

static const struct user_regset_view user_s390_view = {
	.name = UTS_MACHINE,
	.e_machine = EM_S390,
	.regsets = s390_regsets,
	.n = ARRAY_SIZE(s390_regsets)
};

#ifdef CONFIG_COMPAT
static int s390_compat_regs_get(struct task_struct *target,
				const struct user_regset *regset,
				unsigned int pos, unsigned int count,
				void *kbuf, void __user *ubuf)
{
	if (target == current)
		save_access_regs(target->thread.acrs);

	if (kbuf) {
		compat_ulong_t *k = kbuf;
		while (count > 0) {
			*k++ = __peek_user_compat(target, pos);
			count -= sizeof(*k);
			pos += sizeof(*k);
		}
	} else {
		compat_ulong_t __user *u = ubuf;
		while (count > 0) {
			if (__put_user(__peek_user_compat(target, pos), u++))
				return -EFAULT;
			count -= sizeof(*u);
			pos += sizeof(*u);
		}
	}
	return 0;
}

static int s390_compat_regs_set(struct task_struct *target,
				const struct user_regset *regset,
				unsigned int pos, unsigned int count,
				const void *kbuf, const void __user *ubuf)
{
	int rc = 0;

	if (target == current)
		save_access_regs(target->thread.acrs);

	if (kbuf) {
		const compat_ulong_t *k = kbuf;
		while (count > 0 && !rc) {
			rc = __poke_user_compat(target, pos, *k++);
			count -= sizeof(*k);
			pos += sizeof(*k);
		}
	} else {
		const compat_ulong_t  __user *u = ubuf;
		while (count > 0 && !rc) {
			compat_ulong_t word;
			rc = __get_user(word, u++);
			if (rc)
				break;
			rc = __poke_user_compat(target, pos, word);
			count -= sizeof(*u);
			pos += sizeof(*u);
		}
	}

	if (rc == 0 && target == current)
		restore_access_regs(target->thread.acrs);

	return rc;
}

static int s390_compat_regs_high_get(struct task_struct *target,
				     const struct user_regset *regset,
				     unsigned int pos, unsigned int count,
				     void *kbuf, void __user *ubuf)
{
	compat_ulong_t *gprs_high;

	gprs_high = (compat_ulong_t *)
		&task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
	if (kbuf) {
		compat_ulong_t *k = kbuf;
		while (count > 0) {
			*k++ = *gprs_high;
			gprs_high += 2;
			count -= sizeof(*k);
		}
	} else {
		compat_ulong_t __user *u = ubuf;
		while (count > 0) {
			if (__put_user(*gprs_high, u++))
				return -EFAULT;
			gprs_high += 2;
			count -= sizeof(*u);
		}
	}
	return 0;
}

static int s390_compat_regs_high_set(struct task_struct *target,
				     const struct user_regset *regset,
				     unsigned int pos, unsigned int count,
				     const void *kbuf, const void __user *ubuf)
{
	compat_ulong_t *gprs_high;
	int rc = 0;

	gprs_high = (compat_ulong_t *)
		&task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
	if (kbuf) {
		const compat_ulong_t *k = kbuf;
		while (count > 0) {
			*gprs_high = *k++;
			*gprs_high += 2;
			count -= sizeof(*k);
		}
	} else {
		const compat_ulong_t  __user *u = ubuf;
		while (count > 0 && !rc) {
			unsigned long word;
			rc = __get_user(word, u++);
			if (rc)
				break;
			*gprs_high = word;
			*gprs_high += 2;
			count -= sizeof(*u);
		}
	}

	return rc;
}

static const struct user_regset s390_compat_regsets[] = {
	[REGSET_GENERAL] = {
		.core_note_type = NT_PRSTATUS,
		.n = sizeof(s390_compat_regs) / sizeof(compat_long_t),
		.size = sizeof(compat_long_t),
		.align = sizeof(compat_long_t),
		.get = s390_compat_regs_get,
		.set = s390_compat_regs_set,
	},
	[REGSET_FP] = {
		.core_note_type = NT_PRFPREG,
		.n = sizeof(s390_fp_regs) / sizeof(compat_long_t),
		.size = sizeof(compat_long_t),
		.align = sizeof(compat_long_t),
		.get = s390_fpregs_get,
		.set = s390_fpregs_set,
	},
	[REGSET_GENERAL_EXTENDED] = {
		.core_note_type = NT_S390_HIGH_GPRS,
		.n = sizeof(s390_compat_regs_high) / sizeof(compat_long_t),
		.size = sizeof(compat_long_t),
		.align = sizeof(compat_long_t),
		.get = s390_compat_regs_high_get,
		.set = s390_compat_regs_high_set,
	},
};

static const struct user_regset_view user_s390_compat_view = {
	.name = "s390",
	.e_machine = EM_S390,
	.regsets = s390_compat_regsets,
	.n = ARRAY_SIZE(s390_compat_regsets)
};
#endif

const struct user_regset_view *task_user_regset_view(struct task_struct *task)
{
#ifdef CONFIG_COMPAT
	if (test_tsk_thread_flag(task, TIF_31BIT))
		return &user_s390_compat_view;
#endif
	return &user_s390_view;
}
OpenPOWER on IntegriCloud