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", "$14", "$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", "$14", "$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", "$14", "$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 */