summaryrefslogtreecommitdiffstats
path: root/include/asm-mips/uaccess.h
blob: c62c20e7b5c669dc29dd7273c7bb771e7dc12f14 (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
/*
 * 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.
 *
 * Copyright (C) 1996, 1997, 1998, 1999, 2000, 03, 04 by Ralf Baechle
 * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
 */
#ifndef _ASM_UACCESS_H
#define _ASM_UACCESS_H

#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/thread_info.h>
#include <asm-generic/uaccess.h>

/*
 * The fs value determines whether argument validity checking should be
 * performed or not.  If get_fs() == USER_DS, checking is performed, with
 * get_fs() == KERNEL_DS, checking is bypassed.
 *
 * For historical reasons, these macros are grossly misnamed.
 */
#ifdef CONFIG_32BIT

#define __UA_LIMIT	0x80000000UL

#define __UA_ADDR	".word"
#define __UA_LA		"la"
#define __UA_ADDU	"addu"
#define __UA_t0		"$8"
#define __UA_t1		"$9"

#endif /* CONFIG_32BIT */

#ifdef CONFIG_64BIT

#define __UA_LIMIT	(- TASK_SIZE)

#define __UA_ADDR	".dword"
#define __UA_LA		"dla"
#define __UA_ADDU	"daddu"
#define __UA_t0		"$12"
#define __UA_t1		"$13"

#endif /* CONFIG_64BIT */

/*
 * USER_DS is a bitmask that has the bits set that may not be set in a valid
 * userspace address.  Note that we limit 32-bit userspace to 0x7fff8000 but
 * the arithmetic we're doing only works if the limit is a power of two, so
 * we use 0x80000000 here on 32-bit kernels.  If a process passes an invalid
 * address in this range it's the process's problem, not ours :-)
 */

#define KERNEL_DS	((mm_segment_t) { 0UL })
#define USER_DS		((mm_segment_t) { __UA_LIMIT })

#define VERIFY_READ    0
#define VERIFY_WRITE   1

#define get_ds()	(KERNEL_DS)
#define get_fs()	(current_thread_info()->addr_limit)
#define set_fs(x)	(current_thread_info()->addr_limit = (x))

#define segment_eq(a,b)	((a).seg == (b).seg)


/*
 * Is a address valid? This does a straighforward calculation rather
 * than tests.
 *
 * Address valid if:
 *  - "addr" doesn't have any high-bits set
 *  - AND "size" doesn't have any high-bits set
 *  - AND "addr+size" doesn't have any high-bits set
 *  - OR we are in kernel mode.
 *
 * __ua_size() is a trick to avoid runtime checking of positive constant
 * sizes; for those we already know at compile time that the size is ok.
 */
#define __ua_size(size)							\
	((__builtin_constant_p(size) && (signed long) (size) > 0) ? 0 : (size))

/*
 * access_ok: - Checks if a user space pointer is valid
 * @type: Type of access: %VERIFY_READ or %VERIFY_WRITE.  Note that
 *        %VERIFY_WRITE is a superset of %VERIFY_READ - if it is safe
 *        to write to a block, it is always safe to read from it.
 * @addr: User space pointer to start of block to check
 * @size: Size of block to check
 *
 * Context: User context only.  This function may sleep.
 *
 * Checks if a pointer to a block of memory in user space is valid.
 *
 * Returns true (nonzero) if the memory block may be valid, false (zero)
 * if it is definitely invalid.
 *
 * Note that, depending on architecture, this function probably just
 * checks that the pointer is in the user space range - after calling
 * this function, memory access functions may still return -EFAULT.
 */

#define __access_mask get_fs().seg

#define __access_ok(addr, size, mask)					\
	(((signed long)((mask) & ((addr) | ((addr) + (size)) | __ua_size(size)))) == 0)

#define access_ok(type, addr, size)					\
	likely(__access_ok((unsigned long)(addr), (size),__access_mask))

/*
 * put_user: - Write a simple value into user space.
 * @x:   Value to copy to user space.
 * @ptr: Destination address, in user space.
 *
 * Context: User context only.  This function may sleep.
 *
 * This macro copies a single simple value from kernel space to user
 * space.  It supports simple types like char and int, but not larger
 * data types like structures or arrays.
 *
 * @ptr must have pointer-to-simple-variable type, and @x must be assignable
 * to the result of dereferencing @ptr.
 *
 * Returns zero on success, or -EFAULT on error.
 */
#define put_user(x,ptr)	\
	__put_user_check((x),(ptr),sizeof(*(ptr)))

/*
 * get_user: - Get a simple variable from user space.
 * @x:   Variable to store result.
 * @ptr: Source address, in user space.
 *
 * Context: User context only.  This function may sleep.
 *
 * This macro copies a single simple variable from user space to kernel
 * space.  It supports simple types like char and int, but not larger
 * data types like structures or arrays.
 *
 * @ptr must have pointer-to-simple-variable type, and the result of
 * dereferencing @ptr must be assignable to @x without a cast.
 *
 * Returns zero on success, or -EFAULT on error.
 * On error, the variable @x is set to zero.
 */
#define get_user(x,ptr) \
	__get_user_check((x),(ptr),sizeof(*(ptr)))

/*
 * __put_user: - Write a simple value into user space, with less checking.
 * @x:   Value to copy to user space.
 * @ptr: Destination address, in user space.
 *
 * Context: User context only.  This function may sleep.
 *
 * This macro copies a single simple value from kernel space to user
 * space.  It supports simple types like char and int, but not larger
 * data types like structures or arrays.
 *
 * @ptr must have pointer-to-simple-variable type, and @x must be assignable
 * to the result of dereferencing @ptr.
 *
 * Caller must check the pointer with access_ok() before calling this
 * function.
 *
 * Returns zero on success, or -EFAULT on error.
 */
#define __put_user(x,ptr) \
	__put_user_nocheck((x),(ptr),sizeof(*(ptr)))

/*
 * __get_user: - Get a simple variable from user space, with less checking.
 * @x:   Variable to store result.
 * @ptr: Source address, in user space.
 *
 * Context: User context only.  This function may sleep.
 *
 * This macro copies a single simple variable from user space to kernel
 * space.  It supports simple types like char and int, but not larger
 * data types like structures or arrays.
 *
 * @ptr must have pointer-to-simple-variable type, and the result of
 * dereferencing @ptr must be assignable to @x without a cast.
 *
 * Caller must check the pointer with access_ok() before calling this
 * function.
 *
 * Returns zero on success, or -EFAULT on error.
 * On error, the variable @x is set to zero.
 */
#define __get_user(x,ptr) \
	__get_user_nocheck((x),(ptr),sizeof(*(ptr)))

struct __large_struct { unsigned long buf[100]; };
#define __m(x) (*(struct __large_struct __user *)(x))

/*
 * Yuck.  We need two variants, one for 64bit operation and one
 * for 32 bit mode and old iron.
 */
#ifdef CONFIG_32BIT
#define __GET_USER_DW(val, ptr) __get_user_asm_ll32(val, ptr)
#endif
#ifdef CONFIG_64BIT
#define __GET_USER_DW(val, ptr) __get_user_asm(val, "ld", ptr)
#endif

extern void __get_user_unknown(void);

#define __get_user_common(val, size, ptr)				\
do {									\
	switch (size) {							\
	case 1: __get_user_asm(val, "lb", ptr); break;			\
	case 2: __get_user_asm(val, "lh", ptr); break;			\
	case 4: __get_user_asm(val, "lw", ptr); break;			\
	case 8: __GET_USER_DW(val, ptr); break;				\
	default: __get_user_unknown(); break;				\
	}								\
} while (0)

#define __get_user_nocheck(x,ptr,size)					\
({									\
	long __gu_err;							\
									\
	__get_user_common((x), size, ptr);				\
	__gu_err;							\
})

#define __get_user_check(x,ptr,size)					\
({									\
	long __gu_err = -EFAULT;					\
	const __typeof__(*(ptr)) __user * __gu_ptr = (ptr);		\
									\
	if (likely(access_ok(VERIFY_READ,  __gu_ptr, size)))		\
		__get_user_common((x), size, __gu_ptr);			\
									\
	__gu_err;							\
})

#define __get_user_asm(val, insn, addr)					\
{									\
	long __gu_tmp;							\
									\
	__asm__ __volatile__(						\
	"1:	" insn "	%1, %3				\n"	\
	"2:							\n"	\
	"	.section .fixup,\"ax\"				\n"	\
	"3:	li	%0, %4					\n"	\
	"	j	2b					\n"	\
	"	.previous					\n"	\
	"	.section __ex_table,\"a\"			\n"	\
	"	"__UA_ADDR "\t1b, 3b				\n"	\
	"	.previous					\n"	\
	: "=r" (__gu_err), "=r" (__gu_tmp)				\
	: "0" (0), "o" (__m(addr)), "i" (-EFAULT));			\
									\
	(val) = (__typeof__(*(addr))) __gu_tmp;				\
}

/*
 * Get a long long 64 using 32 bit registers.
 */
#define __get_user_asm_ll32(val, addr)					\
{									\
	union {								\
		unsigned long long	l;				\
		__typeof__(*(addr))	t;				\
	} __gu_tmp;							\
									\
	__asm__ __volatile__(						\
	"1:	lw	%1, (%3)				\n"	\
	"2:	lw	%D1, 4(%3)				\n"	\
	"3:	.section	.fixup,\"ax\"			\n"	\
	"4:	li	%0, %4					\n"	\
	"	move	%1, $0					\n"	\
	"	move	%D1, $0					\n"	\
	"	j	3b					\n"	\
	"	.previous					\n"	\
	"	.section	__ex_table,\"a\"		\n"	\
	"	" __UA_ADDR "	1b, 4b				\n"	\
	"	" __UA_ADDR "	2b, 4b				\n"	\
	"	.previous					\n"	\
	: "=r" (__gu_err), "=&r" (__gu_tmp.l)				\
	: "0" (0), "r" (addr), "i" (-EFAULT));				\
									\
	(val) = __gu_tmp.t;						\
}

/*
 * Yuck.  We need two variants, one for 64bit operation and one
 * for 32 bit mode and old iron.
 */
#ifdef CONFIG_32BIT
#define __PUT_USER_DW(ptr) __put_user_asm_ll32(ptr)
#endif
#ifdef CONFIG_64BIT
#define __PUT_USER_DW(ptr) __put_user_asm("sd", ptr)
#endif

#define __put_user_nocheck(x,ptr,size)					\
({									\
	__typeof__(*(ptr)) __pu_val;					\
	long __pu_err = 0;						\
									\
	__pu_val = (x);							\
	switch (size) {							\
	case 1: __put_user_asm("sb", ptr); break;			\
	case 2: __put_user_asm("sh", ptr); break;			\
	case 4: __put_user_asm("sw", ptr); break;			\
	case 8: __PUT_USER_DW(ptr); break;				\
	default: __put_user_unknown(); break;				\
	}								\
	__pu_err;							\
})

#define __put_user_check(x,ptr,size)					\
({									\
	__typeof__(*(ptr)) __user *__pu_addr = (ptr);			\
	__typeof__(*(ptr)) __pu_val = (x);				\
	long __pu_err = -EFAULT;					\
									\
	if (likely(access_ok(VERIFY_WRITE,  __pu_addr, size))) {	\
		switch (size) {						\
		case 1: __put_user_asm("sb", __pu_addr); break;		\
		case 2: __put_user_asm("sh", __pu_addr); break;		\
		case 4: __put_user_asm("sw", __pu_addr); break;		\
		case 8: __PUT_USER_DW(__pu_addr); break;		\
		default: __put_user_unknown(); break;			\
		}							\
	}								\
	__pu_err;							\
})

#define __put_user_asm(insn, ptr)					\
{									\
	__asm__ __volatile__(						\
	"1:	" insn "	%z2, %3		# __put_user_asm\n"	\
	"2:							\n"	\
	"	.section	.fixup,\"ax\"			\n"	\
	"3:	li	%0, %4					\n"	\
	"	j	2b					\n"	\
	"	.previous					\n"	\
	"	.section	__ex_table,\"a\"		\n"	\
	"	" __UA_ADDR "	1b, 3b				\n"	\
	"	.previous					\n"	\
	: "=r" (__pu_err)						\
	: "0" (0), "Jr" (__pu_val), "o" (__m(ptr)),			\
	  "i" (-EFAULT));						\
}

#define __put_user_asm_ll32(ptr)					\
{									\
	__asm__ __volatile__(						\
	"1:	sw	%2, (%3)	# __put_user_asm_ll32	\n"	\
	"2:	sw	%D2, 4(%3)				\n"	\
	"3:							\n"	\
	"	.section	.fixup,\"ax\"			\n"	\
	"4:	li	%0, %4					\n"	\
	"	j	3b					\n"	\
	"	.previous					\n"	\
	"	.section	__ex_table,\"a\"		\n"	\
	"	" __UA_ADDR "	1b, 4b				\n"	\
	"	" __UA_ADDR "	2b, 4b				\n"	\
	"	.previous"						\
	: "=r" (__pu_err)						\
	: "0" (0), "r" (__pu_val), "r" (ptr),				\
	  "i" (-EFAULT));						\
}

extern void __put_user_unknown(void);

/*
 * We're generating jump to subroutines which will be outside the range of
 * jump instructions
 */
#ifdef MODULE
#define __MODULE_JAL(destination)					\
	".set\tnoat\n\t"						\
	__UA_LA "\t$1, " #destination "\n\t" 				\
	"jalr\t$1\n\t"							\
	".set\tat\n\t"
#else
#define __MODULE_JAL(destination)					\
	"jal\t" #destination "\n\t"
#endif

extern size_t __copy_user(void *__to, const void *__from, size_t __n);

#define __invoke_copy_to_user(to,from,n)				\
({									\
	register void __user *__cu_to_r __asm__ ("$4");			\
	register const void *__cu_from_r __asm__ ("$5");		\
	register long __cu_len_r __asm__ ("$6");			\
									\
	__cu_to_r = (to);						\
	__cu_from_r = (from);						\
	__cu_len_r = (n);						\
	__asm__ __volatile__(						\
	__MODULE_JAL(__copy_user)					\
	: "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r)	\
	:								\
	: "$8", "$9", "$10", "$11", "$12", "$15", "$24", "$31",		\
	  "memory");							\
	__cu_len_r;							\
})

/*
 * __copy_to_user: - Copy a block of data into user space, with less checking.
 * @to:   Destination address, in user space.
 * @from: Source address, in kernel space.
 * @n:    Number of bytes to copy.
 *
 * Context: User context only.  This function may sleep.
 *
 * Copy data from kernel space to user space.  Caller must check
 * the specified block with access_ok() before calling this function.
 *
 * Returns number of bytes that could not be copied.
 * On success, this will be zero.
 */
#define __copy_to_user(to,from,n)					\
({									\
	void __user *__cu_to;						\
	const void *__cu_from;						\
	long __cu_len;							\
									\
	might_sleep();							\
	__cu_to = (to);							\
	__cu_from = (from);						\
	__cu_len = (n);							\
	__cu_len = __invoke_copy_to_user(__cu_to, __cu_from, __cu_len);	\
	__cu_len;							\
})

#define __copy_to_user_inatomic(to,from,n)				\
({									\
	void __user *__cu_to;						\
	const void *__cu_from;						\
	long __cu_len;							\
									\
	__cu_to = (to);							\
	__cu_from = (from);						\
	__cu_len = (n);							\
	__cu_len = __invoke_copy_to_user(__cu_to, __cu_from, __cu_len);	\
	__cu_len;							\
})

#define __copy_from_user_inatomic(to,from,n)				\
({									\
	void *__cu_to;							\
	const void __user *__cu_from;					\
	long __cu_len;							\
									\
	__cu_to = (to);							\
	__cu_from = (from);						\
	__cu_len = (n);							\
	__cu_len = __invoke_copy_from_user_inatomic(__cu_to, __cu_from,	\
	                                            __cu_len);		\
	__cu_len;							\
})

/*
 * copy_to_user: - Copy a block of data into user space.
 * @to:   Destination address, in user space.
 * @from: Source address, in kernel space.
 * @n:    Number of bytes to copy.
 *
 * Context: User context only.  This function may sleep.
 *
 * Copy data from kernel space to user space.
 *
 * Returns number of bytes that could not be copied.
 * On success, this will be zero.
 */
#define copy_to_user(to,from,n)						\
({									\
	void __user *__cu_to;						\
	const void *__cu_from;						\
	long __cu_len;							\
									\
	might_sleep();							\
	__cu_to = (to);							\
	__cu_from = (from);						\
	__cu_len = (n);							\
	if (access_ok(VERIFY_WRITE, __cu_to, __cu_len))			\
		__cu_len = __invoke_copy_to_user(__cu_to, __cu_from,	\
		                                 __cu_len);		\
	__cu_len;							\
})

#define __invoke_copy_from_user(to,from,n)				\
({									\
	register void *__cu_to_r __asm__ ("$4");			\
	register const void __user *__cu_from_r __asm__ ("$5");		\
	register long __cu_len_r __asm__ ("$6");			\
									\
	__cu_to_r = (to);						\
	__cu_from_r = (from);						\
	__cu_len_r = (n);						\
	__asm__ __volatile__(						\
	".set\tnoreorder\n\t"						\
	__MODULE_JAL(__copy_user)					\
	".set\tnoat\n\t"						\
	__UA_ADDU "\t$1, %1, %2\n\t"					\
	".set\tat\n\t"							\
	".set\treorder"							\
	: "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r)	\
	:								\
	: "$8", "$9", "$10", "$11", "$12", "$15", "$24", "$31",		\
	  "memory");							\
	__cu_len_r;							\
})

#define __invoke_copy_from_user_inatomic(to,from,n)			\
({									\
	register void *__cu_to_r __asm__ ("$4");			\
	register const void __user *__cu_from_r __asm__ ("$5");		\
	register long __cu_len_r __asm__ ("$6");			\
									\
	__cu_to_r = (to);						\
	__cu_from_r = (from);						\
	__cu_len_r = (n);						\
	__asm__ __volatile__(						\
	".set\tnoreorder\n\t"						\
	__MODULE_JAL(__copy_user_inatomic)				\
	".set\tnoat\n\t"						\
	__UA_ADDU "\t$1, %1, %2\n\t"					\
	".set\tat\n\t"							\
	".set\treorder"							\
	: "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r)	\
	:								\
	: "$8", "$9", "$10", "$11", "$12", "$15", "$24", "$31",		\
	  "memory");							\
	__cu_len_r;							\
})

/*
 * __copy_from_user: - Copy a block of data from user space, with less checking.
 * @to:   Destination address, in kernel space.
 * @from: Source address, in user space.
 * @n:    Number of bytes to copy.
 *
 * Context: User context only.  This function may sleep.
 *
 * Copy data from user space to kernel space.  Caller must check
 * the specified block with access_ok() before calling this function.
 *
 * Returns number of bytes that could not be copied.
 * On success, this will be zero.
 *
 * If some data could not be copied, this function will pad the copied
 * data to the requested size using zero bytes.
 */
#define __copy_from_user(to,from,n)					\
({									\
	void *__cu_to;							\
	const void __user *__cu_from;					\
	long __cu_len;							\
									\
	might_sleep();							\
	__cu_to = (to);							\
	__cu_from = (from);						\
	__cu_len = (n);							\
	__cu_len = __invoke_copy_from_user(__cu_to, __cu_from,		\
	                                   __cu_len);			\
	__cu_len;							\
})

/*
 * copy_from_user: - Copy a block of data from user space.
 * @to:   Destination address, in kernel space.
 * @from: Source address, in user space.
 * @n:    Number of bytes to copy.
 *
 * Context: User context only.  This function may sleep.
 *
 * Copy data from user space to kernel space.
 *
 * Returns number of bytes that could not be copied.
 * On success, this will be zero.
 *
 * If some data could not be copied, this function will pad the copied
 * data to the requested size using zero bytes.
 */
#define copy_from_user(to,from,n)					\
({									\
	void *__cu_to;							\
	const void __user *__cu_from;					\
	long __cu_len;							\
									\
	might_sleep();							\
	__cu_to = (to);							\
	__cu_from = (from);						\
	__cu_len = (n);							\
	if (access_ok(VERIFY_READ, __cu_from, __cu_len))		\
		__cu_len = __invoke_copy_from_user(__cu_to, __cu_from,	\
		                                   __cu_len);		\
	__cu_len;							\
})

#define __copy_in_user(to, from, n)	__copy_from_user(to, from, n)

#define copy_in_user(to,from,n)						\
({									\
	void __user *__cu_to;						\
	const void __user *__cu_from;					\
	long __cu_len;							\
									\
	might_sleep();							\
	__cu_to = (to);							\
	__cu_from = (from);						\
	__cu_len = (n);							\
	if (likely(access_ok(VERIFY_READ, __cu_from, __cu_len) &&	\
	           access_ok(VERIFY_WRITE, __cu_to, __cu_len)))		\
		__cu_len = __invoke_copy_from_user(__cu_to, __cu_from,	\
		                                   __cu_len);		\
	__cu_len;							\
})

/*
 * __clear_user: - Zero a block of memory in user space, with less checking.
 * @to:   Destination address, in user space.
 * @n:    Number of bytes to zero.
 *
 * Zero a block of memory in user space.  Caller must check
 * the specified block with access_ok() before calling this function.
 *
 * Returns number of bytes that could not be cleared.
 * On success, this will be zero.
 */
static inline __kernel_size_t
__clear_user(void __user *addr, __kernel_size_t size)
{
	__kernel_size_t res;

	might_sleep();
	__asm__ __volatile__(
		"move\t$4, %1\n\t"
		"move\t$5, $0\n\t"
		"move\t$6, %2\n\t"
		__MODULE_JAL(__bzero)
		"move\t%0, $6"
		: "=r" (res)
		: "r" (addr), "r" (size)
		: "$4", "$5", "$6", __UA_t0, __UA_t1, "$31");

	return res;
}

#define clear_user(addr,n)						\
({									\
	void __user * __cl_addr = (addr);				\
	unsigned long __cl_size = (n);					\
	if (__cl_size && access_ok(VERIFY_WRITE,			\
		((unsigned long)(__cl_addr)), __cl_size))		\
		__cl_size = __clear_user(__cl_addr, __cl_size);		\
	__cl_size;							\
})

/*
 * __strncpy_from_user: - Copy a NUL terminated string from userspace, with less checking.
 * @dst:   Destination address, in kernel space.  This buffer must be at
 *         least @count bytes long.
 * @src:   Source address, in user space.
 * @count: Maximum number of bytes to copy, including the trailing NUL.
 *
 * Copies a NUL-terminated string from userspace to kernel space.
 * Caller must check the specified block with access_ok() before calling
 * this function.
 *
 * On success, returns the length of the string (not including the trailing
 * NUL).
 *
 * If access to userspace fails, returns -EFAULT (some data may have been
 * copied).
 *
 * If @count is smaller than the length of the string, copies @count bytes
 * and returns @count.
 */
static inline long
__strncpy_from_user(char *__to, const char __user *__from, long __len)
{
	long res;

	might_sleep();
	__asm__ __volatile__(
		"move\t$4, %1\n\t"
		"move\t$5, %2\n\t"
		"move\t$6, %3\n\t"
		__MODULE_JAL(__strncpy_from_user_nocheck_asm)
		"move\t%0, $2"
		: "=r" (res)
		: "r" (__to), "r" (__from), "r" (__len)
		: "$2", "$3", "$4", "$5", "$6", __UA_t0, "$31", "memory");

	return res;
}

/*
 * strncpy_from_user: - Copy a NUL terminated string from userspace.
 * @dst:   Destination address, in kernel space.  This buffer must be at
 *         least @count bytes long.
 * @src:   Source address, in user space.
 * @count: Maximum number of bytes to copy, including the trailing NUL.
 *
 * Copies a NUL-terminated string from userspace to kernel space.
 *
 * On success, returns the length of the string (not including the trailing
 * NUL).
 *
 * If access to userspace fails, returns -EFAULT (some data may have been
 * copied).
 *
 * If @count is smaller than the length of the string, copies @count bytes
 * and returns @count.
 */
static inline long
strncpy_from_user(char *__to, const char __user *__from, long __len)
{
	long res;

	might_sleep();
	__asm__ __volatile__(
		"move\t$4, %1\n\t"
		"move\t$5, %2\n\t"
		"move\t$6, %3\n\t"
		__MODULE_JAL(__strncpy_from_user_asm)
		"move\t%0, $2"
		: "=r" (res)
		: "r" (__to), "r" (__from), "r" (__len)
		: "$2", "$3", "$4", "$5", "$6", __UA_t0, "$31", "memory");

	return res;
}

/* Returns: 0 if bad, string length+1 (memory size) of string if ok */
static inline long __strlen_user(const char __user *s)
{
	long res;

	might_sleep();
	__asm__ __volatile__(
		"move\t$4, %1\n\t"
		__MODULE_JAL(__strlen_user_nocheck_asm)
		"move\t%0, $2"
		: "=r" (res)
		: "r" (s)
		: "$2", "$4", __UA_t0, "$31");

	return res;
}

/*
 * strlen_user: - Get the size of a string in user space.
 * @str: The string to measure.
 *
 * Context: User context only.  This function may sleep.
 *
 * Get the size of a NUL-terminated string in user space.
 *
 * Returns the size of the string INCLUDING the terminating NUL.
 * On exception, returns 0.
 *
 * If there is a limit on the length of a valid string, you may wish to
 * consider using strnlen_user() instead.
 */
static inline long strlen_user(const char __user *s)
{
	long res;

	might_sleep();
	__asm__ __volatile__(
		"move\t$4, %1\n\t"
		__MODULE_JAL(__strlen_user_asm)
		"move\t%0, $2"
		: "=r" (res)
		: "r" (s)
		: "$2", "$4", __UA_t0, "$31");

	return res;
}

/* Returns: 0 if bad, string length+1 (memory size) of string if ok */
static inline long __strnlen_user(const char __user *s, long n)
{
	long res;

	might_sleep();
	__asm__ __volatile__(
		"move\t$4, %1\n\t"
		"move\t$5, %2\n\t"
		__MODULE_JAL(__strnlen_user_nocheck_asm)
		"move\t%0, $2"
		: "=r" (res)
		: "r" (s), "r" (n)
		: "$2", "$4", "$5", __UA_t0, "$31");

	return res;
}

/*
 * strlen_user: - Get the size of a string in user space.
 * @str: The string to measure.
 *
 * Context: User context only.  This function may sleep.
 *
 * Get the size of a NUL-terminated string in user space.
 *
 * Returns the size of the string INCLUDING the terminating NUL.
 * On exception, returns 0.
 *
 * If there is a limit on the length of a valid string, you may wish to
 * consider using strnlen_user() instead.
 */
static inline long strnlen_user(const char __user *s, long n)
{
	long res;

	might_sleep();
	__asm__ __volatile__(
		"move\t$4, %1\n\t"
		"move\t$5, %2\n\t"
		__MODULE_JAL(__strnlen_user_asm)
		"move\t%0, $2"
		: "=r" (res)
		: "r" (s), "r" (n)
		: "$2", "$4", "$5", __UA_t0, "$31");

	return res;
}

struct exception_table_entry
{
	unsigned long insn;
	unsigned long nextinsn;
};

extern int fixup_exception(struct pt_regs *regs);

#endif /* _ASM_UACCESS_H */