2
* This file is subject to the terms and conditions of the GNU General Public
3
* License. See the file "COPYING" in the main directory of this archive
6
* Copyright (C) 1996, 1997, 1998, 1999, 2000, 03, 04 by Ralf Baechle
7
* Copyright (C) 1999, 2000 Silicon Graphics, Inc.
8
* Copyright (C) 2007 Maciej W. Rozycki
10
#ifndef _ASM_UACCESS_H
11
#define _ASM_UACCESS_H
13
#include <linux/kernel.h>
14
#include <linux/errno.h>
15
#include <linux/thread_info.h>
18
* The fs value determines whether argument validity checking should be
19
* performed or not. If get_fs() == USER_DS, checking is performed, with
20
* get_fs() == KERNEL_DS, checking is bypassed.
22
* For historical reasons, these macros are grossly misnamed.
26
#define __UA_LIMIT 0x80000000UL
28
#define __UA_ADDR ".word"
30
#define __UA_ADDU "addu"
34
#endif /* CONFIG_32BIT */
38
extern u64 __ua_limit;
40
#define __UA_LIMIT __ua_limit
42
#define __UA_ADDR ".dword"
44
#define __UA_ADDU "daddu"
48
#endif /* CONFIG_64BIT */
51
* USER_DS is a bitmask that has the bits set that may not be set in a valid
52
* userspace address. Note that we limit 32-bit userspace to 0x7fff8000 but
53
* the arithmetic we're doing only works if the limit is a power of two, so
54
* we use 0x80000000 here on 32-bit kernels. If a process passes an invalid
55
* address in this range it's the process's problem, not ours :-)
58
#define KERNEL_DS ((mm_segment_t) { 0UL })
59
#define USER_DS ((mm_segment_t) { __UA_LIMIT })
62
#define VERIFY_WRITE 1
64
#define get_ds() (KERNEL_DS)
65
#define get_fs() (current_thread_info()->addr_limit)
66
#define set_fs(x) (current_thread_info()->addr_limit = (x))
68
#define segment_eq(a, b) ((a).seg == (b).seg)
72
* Is a address valid? This does a straighforward calculation rather
76
* - "addr" doesn't have any high-bits set
77
* - AND "size" doesn't have any high-bits set
78
* - AND "addr+size" doesn't have any high-bits set
79
* - OR we are in kernel mode.
81
* __ua_size() is a trick to avoid runtime checking of positive constant
82
* sizes; for those we already know at compile time that the size is ok.
84
#define __ua_size(size) \
85
((__builtin_constant_p(size) && (signed long) (size) > 0) ? 0 : (size))
88
* access_ok: - Checks if a user space pointer is valid
89
* @type: Type of access: %VERIFY_READ or %VERIFY_WRITE. Note that
90
* %VERIFY_WRITE is a superset of %VERIFY_READ - if it is safe
91
* to write to a block, it is always safe to read from it.
92
* @addr: User space pointer to start of block to check
93
* @size: Size of block to check
95
* Context: User context only. This function may sleep.
97
* Checks if a pointer to a block of memory in user space is valid.
99
* Returns true (nonzero) if the memory block may be valid, false (zero)
100
* if it is definitely invalid.
102
* Note that, depending on architecture, this function probably just
103
* checks that the pointer is in the user space range - after calling
104
* this function, memory access functions may still return -EFAULT.
107
#define __access_mask get_fs().seg
109
#define __access_ok(addr, size, mask) \
111
unsigned long __addr = (unsigned long) (addr); \
112
unsigned long __size = size; \
113
unsigned long __mask = mask; \
114
unsigned long __ok; \
116
__chk_user_ptr(addr); \
117
__ok = (signed long)(__mask & (__addr | (__addr + __size) | \
118
__ua_size(__size))); \
122
#define access_ok(type, addr, size) \
123
likely(__access_ok((addr), (size), __access_mask))
126
* put_user: - Write a simple value into user space.
127
* @x: Value to copy to user space.
128
* @ptr: Destination address, in user space.
130
* Context: User context only. This function may sleep.
132
* This macro copies a single simple value from kernel space to user
133
* space. It supports simple types like char and int, but not larger
134
* data types like structures or arrays.
136
* @ptr must have pointer-to-simple-variable type, and @x must be assignable
137
* to the result of dereferencing @ptr.
139
* Returns zero on success, or -EFAULT on error.
141
#define put_user(x,ptr) \
142
__put_user_check((x), (ptr), sizeof(*(ptr)))
145
* get_user: - Get a simple variable from user space.
146
* @x: Variable to store result.
147
* @ptr: Source address, in user space.
149
* Context: User context only. This function may sleep.
151
* This macro copies a single simple variable from user space to kernel
152
* space. It supports simple types like char and int, but not larger
153
* data types like structures or arrays.
155
* @ptr must have pointer-to-simple-variable type, and the result of
156
* dereferencing @ptr must be assignable to @x without a cast.
158
* Returns zero on success, or -EFAULT on error.
159
* On error, the variable @x is set to zero.
161
#define get_user(x,ptr) \
162
__get_user_check((x), (ptr), sizeof(*(ptr)))
165
* __put_user: - Write a simple value into user space, with less checking.
166
* @x: Value to copy to user space.
167
* @ptr: Destination address, in user space.
169
* Context: User context only. This function may sleep.
171
* This macro copies a single simple value from kernel space to user
172
* space. It supports simple types like char and int, but not larger
173
* data types like structures or arrays.
175
* @ptr must have pointer-to-simple-variable type, and @x must be assignable
176
* to the result of dereferencing @ptr.
178
* Caller must check the pointer with access_ok() before calling this
181
* Returns zero on success, or -EFAULT on error.
183
#define __put_user(x,ptr) \
184
__put_user_nocheck((x), (ptr), sizeof(*(ptr)))
187
* __get_user: - Get a simple variable from user space, with less checking.
188
* @x: Variable to store result.
189
* @ptr: Source address, in user space.
191
* Context: User context only. This function may sleep.
193
* This macro copies a single simple variable from user space to kernel
194
* space. It supports simple types like char and int, but not larger
195
* data types like structures or arrays.
197
* @ptr must have pointer-to-simple-variable type, and the result of
198
* dereferencing @ptr must be assignable to @x without a cast.
200
* Caller must check the pointer with access_ok() before calling this
203
* Returns zero on success, or -EFAULT on error.
204
* On error, the variable @x is set to zero.
206
#define __get_user(x,ptr) \
207
__get_user_nocheck((x), (ptr), sizeof(*(ptr)))
209
struct __large_struct { unsigned long buf[100]; };
210
#define __m(x) (*(struct __large_struct __user *)(x))
213
* Yuck. We need two variants, one for 64bit operation and one
214
* for 32 bit mode and old iron.
217
#define __GET_USER_DW(val, ptr) __get_user_asm_ll32(val, ptr)
220
#define __GET_USER_DW(val, ptr) __get_user_asm(val, "ld", ptr)
223
extern void __get_user_unknown(void);
225
#define __get_user_common(val, size, ptr) \
228
case 1: __get_user_asm(val, "lb", ptr); break; \
229
case 2: __get_user_asm(val, "lh", ptr); break; \
230
case 4: __get_user_asm(val, "lw", ptr); break; \
231
case 8: __GET_USER_DW(val, ptr); break; \
232
default: __get_user_unknown(); break; \
236
#define __get_user_nocheck(x, ptr, size) \
240
__chk_user_ptr(ptr); \
241
__get_user_common((x), size, ptr); \
245
#define __get_user_check(x, ptr, size) \
247
int __gu_err = -EFAULT; \
248
const __typeof__(*(ptr)) __user * __gu_ptr = (ptr); \
251
if (likely(access_ok(VERIFY_READ, __gu_ptr, size))) \
252
__get_user_common((x), size, __gu_ptr); \
257
#define __get_user_asm(val, insn, addr) \
261
__asm__ __volatile__( \
262
"1: " insn " %1, %3 \n" \
264
" .section .fixup,\"ax\" \n" \
268
" .section __ex_table,\"a\" \n" \
269
" "__UA_ADDR "\t1b, 3b \n" \
271
: "=r" (__gu_err), "=r" (__gu_tmp) \
272
: "0" (0), "o" (__m(addr)), "i" (-EFAULT)); \
274
(val) = (__typeof__(*(addr))) __gu_tmp; \
278
* Get a long long 64 using 32 bit registers.
280
#define __get_user_asm_ll32(val, addr) \
283
unsigned long long l; \
284
__typeof__(*(addr)) t; \
287
__asm__ __volatile__( \
288
"1: lw %1, (%3) \n" \
289
"2: lw %D1, 4(%3) \n" \
290
"3: .section .fixup,\"ax\" \n" \
296
" .section __ex_table,\"a\" \n" \
297
" " __UA_ADDR " 1b, 4b \n" \
298
" " __UA_ADDR " 2b, 4b \n" \
300
: "=r" (__gu_err), "=&r" (__gu_tmp.l) \
301
: "0" (0), "r" (addr), "i" (-EFAULT)); \
303
(val) = __gu_tmp.t; \
307
* Yuck. We need two variants, one for 64bit operation and one
308
* for 32 bit mode and old iron.
311
#define __PUT_USER_DW(ptr) __put_user_asm_ll32(ptr)
314
#define __PUT_USER_DW(ptr) __put_user_asm("sd", ptr)
317
#define __put_user_nocheck(x, ptr, size) \
319
__typeof__(*(ptr)) __pu_val; \
322
__chk_user_ptr(ptr); \
325
case 1: __put_user_asm("sb", ptr); break; \
326
case 2: __put_user_asm("sh", ptr); break; \
327
case 4: __put_user_asm("sw", ptr); break; \
328
case 8: __PUT_USER_DW(ptr); break; \
329
default: __put_user_unknown(); break; \
334
#define __put_user_check(x, ptr, size) \
336
__typeof__(*(ptr)) __user *__pu_addr = (ptr); \
337
__typeof__(*(ptr)) __pu_val = (x); \
338
int __pu_err = -EFAULT; \
341
if (likely(access_ok(VERIFY_WRITE, __pu_addr, size))) { \
343
case 1: __put_user_asm("sb", __pu_addr); break; \
344
case 2: __put_user_asm("sh", __pu_addr); break; \
345
case 4: __put_user_asm("sw", __pu_addr); break; \
346
case 8: __PUT_USER_DW(__pu_addr); break; \
347
default: __put_user_unknown(); break; \
353
#define __put_user_asm(insn, ptr) \
355
__asm__ __volatile__( \
356
"1: " insn " %z2, %3 # __put_user_asm\n" \
358
" .section .fixup,\"ax\" \n" \
362
" .section __ex_table,\"a\" \n" \
363
" " __UA_ADDR " 1b, 3b \n" \
366
: "0" (0), "Jr" (__pu_val), "o" (__m(ptr)), \
370
#define __put_user_asm_ll32(ptr) \
372
__asm__ __volatile__( \
373
"1: sw %2, (%3) # __put_user_asm_ll32 \n" \
374
"2: sw %D2, 4(%3) \n" \
376
" .section .fixup,\"ax\" \n" \
380
" .section __ex_table,\"a\" \n" \
381
" " __UA_ADDR " 1b, 4b \n" \
382
" " __UA_ADDR " 2b, 4b \n" \
385
: "0" (0), "r" (__pu_val), "r" (ptr), \
389
extern void __put_user_unknown(void);
392
* put_user_unaligned: - Write a simple value into user space.
393
* @x: Value to copy to user space.
394
* @ptr: Destination address, in user space.
396
* Context: User context only. This function may sleep.
398
* This macro copies a single simple value from kernel space to user
399
* space. It supports simple types like char and int, but not larger
400
* data types like structures or arrays.
402
* @ptr must have pointer-to-simple-variable type, and @x must be assignable
403
* to the result of dereferencing @ptr.
405
* Returns zero on success, or -EFAULT on error.
407
#define put_user_unaligned(x,ptr) \
408
__put_user_unaligned_check((x),(ptr),sizeof(*(ptr)))
411
* get_user_unaligned: - Get a simple variable from user space.
412
* @x: Variable to store result.
413
* @ptr: Source address, in user space.
415
* Context: User context only. This function may sleep.
417
* This macro copies a single simple variable from user space to kernel
418
* space. It supports simple types like char and int, but not larger
419
* data types like structures or arrays.
421
* @ptr must have pointer-to-simple-variable type, and the result of
422
* dereferencing @ptr must be assignable to @x without a cast.
424
* Returns zero on success, or -EFAULT on error.
425
* On error, the variable @x is set to zero.
427
#define get_user_unaligned(x,ptr) \
428
__get_user_unaligned_check((x),(ptr),sizeof(*(ptr)))
431
* __put_user_unaligned: - Write a simple value into user space, with less checking.
432
* @x: Value to copy to user space.
433
* @ptr: Destination address, in user space.
435
* Context: User context only. This function may sleep.
437
* This macro copies a single simple value from kernel space to user
438
* space. It supports simple types like char and int, but not larger
439
* data types like structures or arrays.
441
* @ptr must have pointer-to-simple-variable type, and @x must be assignable
442
* to the result of dereferencing @ptr.
444
* Caller must check the pointer with access_ok() before calling this
447
* Returns zero on success, or -EFAULT on error.
449
#define __put_user_unaligned(x,ptr) \
450
__put_user_unaligned_nocheck((x),(ptr),sizeof(*(ptr)))
453
* __get_user_unaligned: - Get a simple variable from user space, with less checking.
454
* @x: Variable to store result.
455
* @ptr: Source address, in user space.
457
* Context: User context only. This function may sleep.
459
* This macro copies a single simple variable from user space to kernel
460
* space. It supports simple types like char and int, but not larger
461
* data types like structures or arrays.
463
* @ptr must have pointer-to-simple-variable type, and the result of
464
* dereferencing @ptr must be assignable to @x without a cast.
466
* Caller must check the pointer with access_ok() before calling this
469
* Returns zero on success, or -EFAULT on error.
470
* On error, the variable @x is set to zero.
472
#define __get_user_unaligned(x,ptr) \
473
__get_user__unalignednocheck((x),(ptr),sizeof(*(ptr)))
476
* Yuck. We need two variants, one for 64bit operation and one
477
* for 32 bit mode and old iron.
480
#define __GET_USER_UNALIGNED_DW(val, ptr) \
481
__get_user_unaligned_asm_ll32(val, ptr)
484
#define __GET_USER_UNALIGNED_DW(val, ptr) \
485
__get_user_unaligned_asm(val, "uld", ptr)
488
extern void __get_user_unaligned_unknown(void);
490
#define __get_user_unaligned_common(val, size, ptr) \
493
case 1: __get_user_asm(val, "lb", ptr); break; \
494
case 2: __get_user_unaligned_asm(val, "ulh", ptr); break; \
495
case 4: __get_user_unaligned_asm(val, "ulw", ptr); break; \
496
case 8: __GET_USER_UNALIGNED_DW(val, ptr); break; \
497
default: __get_user_unaligned_unknown(); break; \
501
#define __get_user_unaligned_nocheck(x,ptr,size) \
505
__get_user_unaligned_common((x), size, ptr); \
509
#define __get_user_unaligned_check(x,ptr,size) \
511
int __gu_err = -EFAULT; \
512
const __typeof__(*(ptr)) __user * __gu_ptr = (ptr); \
514
if (likely(access_ok(VERIFY_READ, __gu_ptr, size))) \
515
__get_user_unaligned_common((x), size, __gu_ptr); \
520
#define __get_user_unaligned_asm(val, insn, addr) \
524
__asm__ __volatile__( \
525
"1: " insn " %1, %3 \n" \
527
" .section .fixup,\"ax\" \n" \
531
" .section __ex_table,\"a\" \n" \
532
" "__UA_ADDR "\t1b, 3b \n" \
533
" "__UA_ADDR "\t1b + 4, 3b \n" \
535
: "=r" (__gu_err), "=r" (__gu_tmp) \
536
: "0" (0), "o" (__m(addr)), "i" (-EFAULT)); \
538
(val) = (__typeof__(*(addr))) __gu_tmp; \
542
* Get a long long 64 using 32 bit registers.
544
#define __get_user_unaligned_asm_ll32(val, addr) \
546
unsigned long long __gu_tmp; \
548
__asm__ __volatile__( \
549
"1: ulw %1, (%3) \n" \
550
"2: ulw %D1, 4(%3) \n" \
552
"3: .section .fixup,\"ax\" \n" \
558
" .section __ex_table,\"a\" \n" \
559
" " __UA_ADDR " 1b, 4b \n" \
560
" " __UA_ADDR " 1b + 4, 4b \n" \
561
" " __UA_ADDR " 2b, 4b \n" \
562
" " __UA_ADDR " 2b + 4, 4b \n" \
564
: "=r" (__gu_err), "=&r" (__gu_tmp) \
565
: "0" (0), "r" (addr), "i" (-EFAULT)); \
566
(val) = (__typeof__(*(addr))) __gu_tmp; \
570
* Yuck. We need two variants, one for 64bit operation and one
571
* for 32 bit mode and old iron.
574
#define __PUT_USER_UNALIGNED_DW(ptr) __put_user_unaligned_asm_ll32(ptr)
577
#define __PUT_USER_UNALIGNED_DW(ptr) __put_user_unaligned_asm("usd", ptr)
580
#define __put_user_unaligned_nocheck(x,ptr,size) \
582
__typeof__(*(ptr)) __pu_val; \
587
case 1: __put_user_asm("sb", ptr); break; \
588
case 2: __put_user_unaligned_asm("ush", ptr); break; \
589
case 4: __put_user_unaligned_asm("usw", ptr); break; \
590
case 8: __PUT_USER_UNALIGNED_DW(ptr); break; \
591
default: __put_user_unaligned_unknown(); break; \
596
#define __put_user_unaligned_check(x,ptr,size) \
598
__typeof__(*(ptr)) __user *__pu_addr = (ptr); \
599
__typeof__(*(ptr)) __pu_val = (x); \
600
int __pu_err = -EFAULT; \
602
if (likely(access_ok(VERIFY_WRITE, __pu_addr, size))) { \
604
case 1: __put_user_asm("sb", __pu_addr); break; \
605
case 2: __put_user_unaligned_asm("ush", __pu_addr); break; \
606
case 4: __put_user_unaligned_asm("usw", __pu_addr); break; \
607
case 8: __PUT_USER_UNALGINED_DW(__pu_addr); break; \
608
default: __put_user_unaligned_unknown(); break; \
614
#define __put_user_unaligned_asm(insn, ptr) \
616
__asm__ __volatile__( \
617
"1: " insn " %z2, %3 # __put_user_unaligned_asm\n" \
619
" .section .fixup,\"ax\" \n" \
623
" .section __ex_table,\"a\" \n" \
624
" " __UA_ADDR " 1b, 3b \n" \
627
: "0" (0), "Jr" (__pu_val), "o" (__m(ptr)), \
631
#define __put_user_unaligned_asm_ll32(ptr) \
633
__asm__ __volatile__( \
634
"1: sw %2, (%3) # __put_user_unaligned_asm_ll32 \n" \
635
"2: sw %D2, 4(%3) \n" \
637
" .section .fixup,\"ax\" \n" \
641
" .section __ex_table,\"a\" \n" \
642
" " __UA_ADDR " 1b, 4b \n" \
643
" " __UA_ADDR " 1b + 4, 4b \n" \
644
" " __UA_ADDR " 2b, 4b \n" \
645
" " __UA_ADDR " 2b + 4, 4b \n" \
648
: "0" (0), "r" (__pu_val), "r" (ptr), \
652
extern void __put_user_unaligned_unknown(void);
655
* We're generating jump to subroutines which will be outside the range of
659
#define __MODULE_JAL(destination) \
661
__UA_LA "\t$1, " #destination "\n\t" \
665
#define __MODULE_JAL(destination) \
666
"jal\t" #destination "\n\t"
669
#ifndef CONFIG_CPU_DADDI_WORKAROUNDS
670
#define DADDI_SCRATCH "$0"
672
#define DADDI_SCRATCH "$3"
675
extern size_t __copy_user(void *__to, const void *__from, size_t __n);
677
#define __invoke_copy_to_user(to, from, n) \
679
register void __user *__cu_to_r __asm__("$4"); \
680
register const void *__cu_from_r __asm__("$5"); \
681
register long __cu_len_r __asm__("$6"); \
684
__cu_from_r = (from); \
686
__asm__ __volatile__( \
687
__MODULE_JAL(__copy_user) \
688
: "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r) \
690
: "$8", "$9", "$10", "$11", "$12", "$15", "$24", "$31", \
691
DADDI_SCRATCH, "memory"); \
696
* __copy_to_user: - Copy a block of data into user space, with less checking.
697
* @to: Destination address, in user space.
698
* @from: Source address, in kernel space.
699
* @n: Number of bytes to copy.
701
* Context: User context only. This function may sleep.
703
* Copy data from kernel space to user space. Caller must check
704
* the specified block with access_ok() before calling this function.
706
* Returns number of bytes that could not be copied.
707
* On success, this will be zero.
709
#define __copy_to_user(to, from, n) \
711
void __user *__cu_to; \
712
const void *__cu_from; \
716
__cu_from = (from); \
719
__cu_len = __invoke_copy_to_user(__cu_to, __cu_from, __cu_len); \
723
extern size_t __copy_user_inatomic(void *__to, const void *__from, size_t __n);
725
#define __copy_to_user_inatomic(to, from, n) \
727
void __user *__cu_to; \
728
const void *__cu_from; \
732
__cu_from = (from); \
734
__cu_len = __invoke_copy_to_user(__cu_to, __cu_from, __cu_len); \
738
#define __copy_from_user_inatomic(to, from, n) \
741
const void __user *__cu_from; \
745
__cu_from = (from); \
747
__cu_len = __invoke_copy_from_user_inatomic(__cu_to, __cu_from, \
753
* copy_to_user: - Copy a block of data into user space.
754
* @to: Destination address, in user space.
755
* @from: Source address, in kernel space.
756
* @n: Number of bytes to copy.
758
* Context: User context only. This function may sleep.
760
* Copy data from kernel space to user space.
762
* Returns number of bytes that could not be copied.
763
* On success, this will be zero.
765
#define copy_to_user(to, from, n) \
767
void __user *__cu_to; \
768
const void *__cu_from; \
772
__cu_from = (from); \
774
if (access_ok(VERIFY_WRITE, __cu_to, __cu_len)) { \
776
__cu_len = __invoke_copy_to_user(__cu_to, __cu_from, \
782
#define __invoke_copy_from_user(to, from, n) \
784
register void *__cu_to_r __asm__("$4"); \
785
register const void __user *__cu_from_r __asm__("$5"); \
786
register long __cu_len_r __asm__("$6"); \
789
__cu_from_r = (from); \
791
__asm__ __volatile__( \
792
".set\tnoreorder\n\t" \
793
__MODULE_JAL(__copy_user) \
795
__UA_ADDU "\t$1, %1, %2\n\t" \
798
: "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r) \
800
: "$8", "$9", "$10", "$11", "$12", "$15", "$24", "$31", \
801
DADDI_SCRATCH, "memory"); \
805
#define __invoke_copy_from_user_inatomic(to, from, n) \
807
register void *__cu_to_r __asm__("$4"); \
808
register const void __user *__cu_from_r __asm__("$5"); \
809
register long __cu_len_r __asm__("$6"); \
812
__cu_from_r = (from); \
814
__asm__ __volatile__( \
815
".set\tnoreorder\n\t" \
816
__MODULE_JAL(__copy_user_inatomic) \
818
__UA_ADDU "\t$1, %1, %2\n\t" \
821
: "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r) \
823
: "$8", "$9", "$10", "$11", "$12", "$15", "$24", "$31", \
824
DADDI_SCRATCH, "memory"); \
829
* __copy_from_user: - Copy a block of data from user space, with less checking.
830
* @to: Destination address, in kernel space.
831
* @from: Source address, in user space.
832
* @n: Number of bytes to copy.
834
* Context: User context only. This function may sleep.
836
* Copy data from user space to kernel space. Caller must check
837
* the specified block with access_ok() before calling this function.
839
* Returns number of bytes that could not be copied.
840
* On success, this will be zero.
842
* If some data could not be copied, this function will pad the copied
843
* data to the requested size using zero bytes.
845
#define __copy_from_user(to, from, n) \
848
const void __user *__cu_from; \
852
__cu_from = (from); \
855
__cu_len = __invoke_copy_from_user(__cu_to, __cu_from, \
861
* copy_from_user: - Copy a block of data from user space.
862
* @to: Destination address, in kernel space.
863
* @from: Source address, in user space.
864
* @n: Number of bytes to copy.
866
* Context: User context only. This function may sleep.
868
* Copy data from user space to kernel space.
870
* Returns number of bytes that could not be copied.
871
* On success, this will be zero.
873
* If some data could not be copied, this function will pad the copied
874
* data to the requested size using zero bytes.
876
#define copy_from_user(to, from, n) \
879
const void __user *__cu_from; \
883
__cu_from = (from); \
885
if (access_ok(VERIFY_READ, __cu_from, __cu_len)) { \
887
__cu_len = __invoke_copy_from_user(__cu_to, __cu_from, \
893
#define __copy_in_user(to, from, n) \
895
void __user *__cu_to; \
896
const void __user *__cu_from; \
900
__cu_from = (from); \
903
__cu_len = __invoke_copy_from_user(__cu_to, __cu_from, \
908
#define copy_in_user(to, from, n) \
910
void __user *__cu_to; \
911
const void __user *__cu_from; \
915
__cu_from = (from); \
917
if (likely(access_ok(VERIFY_READ, __cu_from, __cu_len) && \
918
access_ok(VERIFY_WRITE, __cu_to, __cu_len))) { \
920
__cu_len = __invoke_copy_from_user(__cu_to, __cu_from, \
927
* __clear_user: - Zero a block of memory in user space, with less checking.
928
* @to: Destination address, in user space.
929
* @n: Number of bytes to zero.
931
* Zero a block of memory in user space. Caller must check
932
* the specified block with access_ok() before calling this function.
934
* Returns number of bytes that could not be cleared.
935
* On success, this will be zero.
937
static inline __kernel_size_t
938
__clear_user(void __user *addr, __kernel_size_t size)
943
__asm__ __volatile__(
947
__MODULE_JAL(__bzero)
950
: "r" (addr), "r" (size)
951
: "$4", "$5", "$6", __UA_t0, __UA_t1, "$31");
956
#define clear_user(addr,n) \
958
void __user * __cl_addr = (addr); \
959
unsigned long __cl_size = (n); \
960
if (__cl_size && access_ok(VERIFY_WRITE, \
961
__cl_addr, __cl_size)) \
962
__cl_size = __clear_user(__cl_addr, __cl_size); \
967
* __strncpy_from_user: - Copy a NUL terminated string from userspace, with less checking.
968
* @dst: Destination address, in kernel space. This buffer must be at
969
* least @count bytes long.
970
* @src: Source address, in user space.
971
* @count: Maximum number of bytes to copy, including the trailing NUL.
973
* Copies a NUL-terminated string from userspace to kernel space.
974
* Caller must check the specified block with access_ok() before calling
977
* On success, returns the length of the string (not including the trailing
980
* If access to userspace fails, returns -EFAULT (some data may have been
983
* If @count is smaller than the length of the string, copies @count bytes
984
* and returns @count.
987
__strncpy_from_user(char *__to, const char __user *__from, long __len)
992
__asm__ __volatile__(
996
__MODULE_JAL(__strncpy_from_user_nocheck_asm)
999
: "r" (__to), "r" (__from), "r" (__len)
1000
: "$2", "$3", "$4", "$5", "$6", __UA_t0, "$31", "memory");
1006
* strncpy_from_user: - Copy a NUL terminated string from userspace.
1007
* @dst: Destination address, in kernel space. This buffer must be at
1008
* least @count bytes long.
1009
* @src: Source address, in user space.
1010
* @count: Maximum number of bytes to copy, including the trailing NUL.
1012
* Copies a NUL-terminated string from userspace to kernel space.
1014
* On success, returns the length of the string (not including the trailing
1017
* If access to userspace fails, returns -EFAULT (some data may have been
1020
* If @count is smaller than the length of the string, copies @count bytes
1021
* and returns @count.
1024
strncpy_from_user(char *__to, const char __user *__from, long __len)
1029
__asm__ __volatile__(
1033
__MODULE_JAL(__strncpy_from_user_asm)
1036
: "r" (__to), "r" (__from), "r" (__len)
1037
: "$2", "$3", "$4", "$5", "$6", __UA_t0, "$31", "memory");
1042
/* Returns: 0 if bad, string length+1 (memory size) of string if ok */
1043
static inline long __strlen_user(const char __user *s)
1048
__asm__ __volatile__(
1050
__MODULE_JAL(__strlen_user_nocheck_asm)
1054
: "$2", "$4", __UA_t0, "$31");
1060
* strlen_user: - Get the size of a string in user space.
1061
* @str: The string to measure.
1063
* Context: User context only. This function may sleep.
1065
* Get the size of a NUL-terminated string in user space.
1067
* Returns the size of the string INCLUDING the terminating NUL.
1068
* On exception, returns 0.
1070
* If there is a limit on the length of a valid string, you may wish to
1071
* consider using strnlen_user() instead.
1073
static inline long strlen_user(const char __user *s)
1078
__asm__ __volatile__(
1080
__MODULE_JAL(__strlen_user_asm)
1084
: "$2", "$4", __UA_t0, "$31");
1089
/* Returns: 0 if bad, string length+1 (memory size) of string if ok */
1090
static inline long __strnlen_user(const char __user *s, long n)
1095
__asm__ __volatile__(
1098
__MODULE_JAL(__strnlen_user_nocheck_asm)
1102
: "$2", "$4", "$5", __UA_t0, "$31");
1108
* strlen_user: - Get the size of a string in user space.
1109
* @str: The string to measure.
1111
* Context: User context only. This function may sleep.
1113
* Get the size of a NUL-terminated string in user space.
1115
* Returns the size of the string INCLUDING the terminating NUL.
1116
* On exception, returns 0.
1118
* If there is a limit on the length of a valid string, you may wish to
1119
* consider using strnlen_user() instead.
1121
static inline long strnlen_user(const char __user *s, long n)
1126
__asm__ __volatile__(
1129
__MODULE_JAL(__strnlen_user_asm)
1133
: "$2", "$4", "$5", __UA_t0, "$31");
1138
struct exception_table_entry
1141
unsigned long nextinsn;
1144
extern int fixup_exception(struct pt_regs *regs);
1146
#endif /* _ASM_UACCESS_H */