1 #ifndef _ASM_M32R_UACCESS_H
2 #define _ASM_M32R_UACCESS_H
5 * linux/include/asm-m32r/uaccess.h
8 * Copyright (C) 2004 Hirokazu Takata <takata at linux-m32r.org>
14 #define UAPRINTK(args...) printk(args)
16 #define UAPRINTK(args...)
17 #endif /* UACCESS_DEBUG */
20 * User space memory access functions
22 #include <linux/config.h>
23 #include <linux/errno.h>
24 #include <linux/thread_info.h>
28 #define VERIFY_WRITE 1
31 * The fs value determines whether argument validity checking should be
32 * performed or not. If get_fs() == USER_DS, checking is performed, with
33 * get_fs() == KERNEL_DS, checking is bypassed.
35 * For historical reasons, these macros are grossly misnamed.
38 #define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
41 #define KERNEL_DS MAKE_MM_SEG(0xFFFFFFFF)
42 #define USER_DS MAKE_MM_SEG(PAGE_OFFSET)
44 #define KERNEL_DS MAKE_MM_SEG(0xFFFFFFFF)
45 #define USER_DS MAKE_MM_SEG(0xFFFFFFFF)
46 #endif /* CONFIG_MMU */
48 #define get_ds() (KERNEL_DS)
50 #define get_fs() (current_thread_info()->addr_limit)
51 #define set_fs(x) (current_thread_info()->addr_limit = (x))
53 static inline mm_segment_t
get_fs(void)
58 static inline void set_fs(mm_segment_t s
)
61 #endif /* CONFIG_MMU */
63 #define segment_eq(a,b) ((a).seg == (b).seg)
65 #define __addr_ok(addr) \
66 ((unsigned long)(addr) < (current_thread_info()->addr_limit.seg))
69 * Test whether a block of memory is a valid user space address.
70 * Returns 0 if the range is valid, nonzero otherwise.
72 * This is equivalent to the following test:
73 * (u33)addr + (u33)size >= (u33)current->addr_limit.seg
75 * This needs 33-bit arithmetic. We have a carry...
77 #define __range_ok(addr,size) ({ \
78 unsigned long flag, sum; \
79 __chk_user_ptr(addr); \
81 " cmpu %1, %1 ; clear cbit\n" \
82 " addx %1, %3 ; set cbit if overflow\n" \
86 : "=&r"(flag), "=r"(sum) \
87 : "1"(addr), "r"((int)(size)), \
88 "r"(current_thread_info()->addr_limit.seg), "r"(0) \
93 * access_ok: - Checks if a user space pointer is valid
94 * @type: Type of access: %VERIFY_READ or %VERIFY_WRITE. Note that
95 * %VERIFY_WRITE is a superset of %VERIFY_READ - if it is safe
96 * to write to a block, it is always safe to read from it.
97 * @addr: User space pointer to start of block to check
98 * @size: Size of block to check
100 * Context: User context only. This function may sleep.
102 * Checks if a pointer to a block of memory in user space is valid.
104 * Returns true (nonzero) if the memory block may be valid, false (zero)
105 * if it is definitely invalid.
107 * Note that, depending on architecture, this function probably just
108 * checks that the pointer is in the user space range - after calling
109 * this function, memory access functions may still return -EFAULT.
112 #define access_ok(type,addr,size) (likely(__range_ok(addr,size) == 0))
114 static inline int access_ok(int type
, const void *addr
, unsigned long size
)
116 extern unsigned long memory_start
, memory_end
;
117 unsigned long val
= (unsigned long)addr
;
119 return ((val
>= memory_start
) && ((val
+ size
) < memory_end
));
121 #endif /* CONFIG_MMU */
124 * The exception table consists of pairs of addresses: the first is the
125 * address of an instruction that is allowed to fault, and the second is
126 * the address at which the program should continue. No registers are
127 * modified, so it is entirely up to the continuation code to figure out
130 * All the routines below use bits of fixup code that are out of line
131 * with the main instruction path. This means when everything is well,
132 * we don't even have to jump over them. Further, they do not intrude
133 * on our cache or tlb entries.
136 struct exception_table_entry
138 unsigned long insn
, fixup
;
141 extern int fixup_exception(struct pt_regs
*regs
);
144 * These are the main single-value transfer routines. They automatically
145 * use the right size if we just have the right pointer type.
147 * This gets kind of ugly. We want to return _two_ values in "get_user()"
148 * and yet we don't want to do any pointers, because that is too much
149 * of a performance impact. Thus we have a few rather ugly macros here,
150 * and hide all the uglyness from the user.
152 * The "__xxx" versions of the user access functions are versions that
153 * do not verify the address space, that must have been done previously
154 * with a separate "access_ok()" call (this is used when we do multiple
155 * accesses to the same area of user memory).
158 extern void __get_user_1(void);
159 extern void __get_user_2(void);
160 extern void __get_user_4(void);
163 #define __get_user_x(size,ret,x,ptr) \
164 __asm__ __volatile__( \
167 " bl __get_user_" #size "\n" \
170 : "=r"(ret), "=r"(x) \
172 : "r0", "r1", "r14" )
175 * Use "jl" instead of "bl" for MODULE
177 #define __get_user_x(size,ret,x,ptr) \
178 __asm__ __volatile__( \
181 " seth lr, #high(__get_user_" #size ")\n" \
182 " or3 lr, lr, #low(__get_user_" #size ")\n" \
186 : "=r"(ret), "=r"(x) \
188 : "r0", "r1", "r14" )
191 /* Careful: we have to cast the result to the type of the pointer for sign
194 * get_user: - Get a simple variable from user space.
195 * @x: Variable to store result.
196 * @ptr: Source address, in user space.
198 * Context: User context only. This function may sleep.
200 * This macro copies a single simple variable from user space to kernel
201 * space. It supports simple types like char and int, but not larger
202 * data types like structures or arrays.
204 * @ptr must have pointer-to-simple-variable type, and the result of
205 * dereferencing @ptr must be assignable to @x without a cast.
207 * Returns zero on success, or -EFAULT on error.
208 * On error, the variable @x is set to zero.
210 #define get_user(x,ptr) \
212 unsigned long __val_gu; \
213 __chk_user_ptr(ptr); \
214 switch(sizeof (*(ptr))) { \
215 case 1: __get_user_x(1,__ret_gu,__val_gu,ptr); break; \
216 case 2: __get_user_x(2,__ret_gu,__val_gu,ptr); break; \
217 case 4: __get_user_x(4,__ret_gu,__val_gu,ptr); break; \
218 default: __get_user_x(X,__ret_gu,__val_gu,ptr); break; \
220 (x) = (__typeof__(*(ptr)))__val_gu; \
224 extern void __put_user_bad(void);
227 * put_user: - Write a simple value into user space.
228 * @x: Value to copy to user space.
229 * @ptr: Destination address, in user space.
231 * Context: User context only. This function may sleep.
233 * This macro copies a single simple value from kernel space to user
234 * space. It supports simple types like char and int, but not larger
235 * data types like structures or arrays.
237 * @ptr must have pointer-to-simple-variable type, and @x must be assignable
238 * to the result of dereferencing @ptr.
240 * Returns zero on success, or -EFAULT on error.
242 #define put_user(x,ptr) \
243 __put_user_check((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))
247 * __get_user: - Get a simple variable from user space, with less checking.
248 * @x: Variable to store result.
249 * @ptr: Source address, in user space.
251 * Context: User context only. This function may sleep.
253 * This macro copies a single simple variable from user space to kernel
254 * space. It supports simple types like char and int, but not larger
255 * data types like structures or arrays.
257 * @ptr must have pointer-to-simple-variable type, and the result of
258 * dereferencing @ptr must be assignable to @x without a cast.
260 * Caller must check the pointer with access_ok() before calling this
263 * Returns zero on success, or -EFAULT on error.
264 * On error, the variable @x is set to zero.
266 #define __get_user(x,ptr) \
267 __get_user_nocheck((x),(ptr),sizeof(*(ptr)))
271 * __put_user: - Write a simple value into user space, with less checking.
272 * @x: Value to copy to user space.
273 * @ptr: Destination address, in user space.
275 * Context: User context only. This function may sleep.
277 * This macro copies a single simple value from kernel space to user
278 * space. It supports simple types like char and int, but not larger
279 * data types like structures or arrays.
281 * @ptr must have pointer-to-simple-variable type, and @x must be assignable
282 * to the result of dereferencing @ptr.
284 * Caller must check the pointer with access_ok() before calling this
287 * Returns zero on success, or -EFAULT on error.
289 #define __put_user(x,ptr) \
290 __put_user_nocheck((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))
292 #define __put_user_nocheck(x,ptr,size) \
295 __put_user_size((x),(ptr),(size),__pu_err); \
300 #define __put_user_check(x,ptr,size) \
302 long __pu_err = -EFAULT; \
303 __typeof__(*(ptr)) __user *__pu_addr = (ptr); \
305 if (access_ok(VERIFY_WRITE,__pu_addr,size)) \
306 __put_user_size((x),__pu_addr,(size),__pu_err); \
310 #if defined(__LITTLE_ENDIAN__)
311 #define __put_user_u64(x, addr, err) \
312 __asm__ __volatile__( \
316 "2: st %H1,@(4,%2)\n" \
319 ".section .fixup,\"ax\"\n" \
322 " seth r14,#high(3b)\n" \
323 " or3 r14,r14,#low(3b)\n" \
326 ".section __ex_table,\"a\"\n" \
332 : "r"(x), "r"(addr), "i"(-EFAULT), "0"(err) \
335 #elif defined(__BIG_ENDIAN__)
336 #define __put_user_u64(x, addr, err) \
337 __asm__ __volatile__( \
341 "2: st %L1,@(4,%2)\n" \
344 ".section .fixup,\"ax\"\n" \
347 " seth r14,#high(3b)\n" \
348 " or3 r14,r14,#low(3b)\n" \
351 ".section __ex_table,\"a\"\n" \
357 : "r"(x), "r"(addr), "i"(-EFAULT), "0"(err) \
360 #error no endian defined
363 #define __put_user_size(x,ptr,size,retval) \
366 __chk_user_ptr(ptr); \
368 case 1: __put_user_asm(x,ptr,retval,"b"); break; \
369 case 2: __put_user_asm(x,ptr,retval,"h"); break; \
370 case 4: __put_user_asm(x,ptr,retval,""); break; \
371 case 8: __put_user_u64((__typeof__(*ptr))(x),ptr,retval); break;\
372 default: __put_user_bad(); \
376 struct __large_struct
{ unsigned long buf
[100]; };
377 #define __m(x) (*(struct __large_struct *)(x))
380 * Tell gcc we read from memory instead of writing: this is because
381 * we do not write to any memory gcc knows about, so there are no
384 #define __put_user_asm(x, addr, err, itype) \
385 __asm__ __volatile__( \
387 "1: st"itype" %1,@%2\n" \
390 ".section .fixup,\"ax\"\n" \
393 " seth r14,#high(2b)\n" \
394 " or3 r14,r14,#low(2b)\n" \
397 ".section __ex_table,\"a\"\n" \
402 : "r"(x), "r"(addr), "i"(-EFAULT), "0"(err) \
405 #define __get_user_nocheck(x,ptr,size) \
408 unsigned long __gu_val; \
409 __get_user_size(__gu_val,(ptr),(size),__gu_err); \
410 (x) = (__typeof__(*(ptr)))__gu_val; \
414 extern long __get_user_bad(void);
416 #define __get_user_size(x,ptr,size,retval) \
419 __chk_user_ptr(ptr); \
421 case 1: __get_user_asm(x,ptr,retval,"ub"); break; \
422 case 2: __get_user_asm(x,ptr,retval,"uh"); break; \
423 case 4: __get_user_asm(x,ptr,retval,""); break; \
424 default: (x) = __get_user_bad(); \
428 #define __get_user_asm(x, addr, err, itype) \
429 __asm__ __volatile__( \
431 "1: ld"itype" %1,@%2\n" \
434 ".section .fixup,\"ax\"\n" \
437 " seth r14,#high(2b)\n" \
438 " or3 r14,r14,#low(2b)\n" \
441 ".section __ex_table,\"a\"\n" \
445 : "=r"(err), "=&r"(x) \
446 : "r"(addr), "i"(-EFAULT), "0"(err) \
450 * Here we special-case 1, 2 and 4-byte copy_*_user invocations. On a fault
451 * we return the initial request size (1, 2 or 4), as copy_*_user should do.
452 * If a store crosses a page boundary and gets a fault, the m32r will not write
453 * anything, so this is accurate.
458 * Copy To/From Userspace
461 /* Generic arbitrary sized copy. */
462 /* Return the number of bytes NOT copied. */
463 #define __copy_user(to,from,size) \
465 unsigned long __dst, __src, __c; \
466 __asm__ __volatile__ ( \
469 " beq %0, %1, 9f\n" \
471 " and3 r14, r14, #3\n" \
473 " and3 %2, %2, #3\n" \
475 " addi %0, #-4 ; word_copy \n" \
477 "0: ld r14, @%1+\n" \
480 "1: st r14, @+%0\n" \
485 "2: ldb r14, @%1 ; byte_copy \n" \
487 "3: stb r14, @%0\n" \
494 ".section .fixup,\"ax\"\n" \
503 "7: seth r14, #high(9b)\n" \
504 " or3 r14, r14, #low(9b)\n" \
507 ".section __ex_table,\"a\"\n" \
514 : "=&r"(__dst), "=&r"(__src), "=&r"(size), "=&r"(__c) \
515 : "0"(to), "1"(from), "2"(size), "3"(size / 4) \
516 : "r14", "memory"); \
519 #define __copy_user_zeroing(to,from,size) \
521 unsigned long __dst, __src, __c; \
522 __asm__ __volatile__ ( \
525 " beq %0, %1, 9f\n" \
527 " and3 r14, r14, #3\n" \
529 " and3 %2, %2, #3\n" \
531 " addi %0, #-4 ; word_copy \n" \
533 "0: ld r14, @%1+\n" \
536 "1: st r14, @+%0\n" \
541 "2: ldb r14, @%1 ; byte_copy \n" \
543 "3: stb r14, @%0\n" \
550 ".section .fixup,\"ax\"\n" \
559 "7: ldi r14, #0 ; store zero \n" \
561 "8: addi %2, #-1\n" \
562 " stb r14, @%0 ; ACE? \n" \
565 " seth r14, #high(9b)\n" \
566 " or3 r14, r14, #low(9b)\n" \
569 ".section __ex_table,\"a\"\n" \
576 : "=&r"(__dst), "=&r"(__src), "=&r"(size), "=&r"(__c) \
577 : "0"(to), "1"(from), "2"(size), "3"(size / 4) \
578 : "r14", "memory"); \
582 /* We let the __ versions of copy_from/to_user inline, because they're often
583 * used in fast paths and have only a small space overhead.
585 static inline unsigned long __generic_copy_from_user_nocheck(void *to
,
586 const void __user
*from
, unsigned long n
)
588 __copy_user_zeroing(to
,from
,n
);
592 static inline unsigned long __generic_copy_to_user_nocheck(void __user
*to
,
593 const void *from
, unsigned long n
)
595 __copy_user(to
,from
,n
);
599 unsigned long __generic_copy_to_user(void __user
*, const void *, unsigned long);
600 unsigned long __generic_copy_from_user(void *, const void __user
*, unsigned long);
603 * __copy_to_user: - Copy a block of data into user space, with less checking.
604 * @to: Destination address, in user space.
605 * @from: Source address, in kernel space.
606 * @n: Number of bytes to copy.
608 * Context: User context only. This function may sleep.
610 * Copy data from kernel space to user space. Caller must check
611 * the specified block with access_ok() before calling this function.
613 * Returns number of bytes that could not be copied.
614 * On success, this will be zero.
616 #define __copy_to_user(to,from,n) \
617 __generic_copy_to_user_nocheck((to),(from),(n))
619 #define __copy_to_user_inatomic __copy_to_user
620 #define __copy_from_user_inatomic __copy_from_user
623 * copy_to_user: - Copy a block of data into user space.
624 * @to: Destination address, in user space.
625 * @from: Source address, in kernel space.
626 * @n: Number of bytes to copy.
628 * Context: User context only. This function may sleep.
630 * Copy data from kernel space to user space.
632 * Returns number of bytes that could not be copied.
633 * On success, this will be zero.
635 #define copy_to_user(to,from,n) \
638 __generic_copy_to_user((to),(from),(n)); \
642 * __copy_from_user: - Copy a block of data from user space, with less checking. * @to: Destination address, in kernel space.
643 * @from: Source address, in user space.
644 * @n: Number of bytes to copy.
646 * Context: User context only. This function may sleep.
648 * Copy data from user space to kernel space. Caller must check
649 * the specified block with access_ok() before calling this function.
651 * Returns number of bytes that could not be copied.
652 * On success, this will be zero.
654 * If some data could not be copied, this function will pad the copied
655 * data to the requested size using zero bytes.
657 #define __copy_from_user(to,from,n) \
658 __generic_copy_from_user_nocheck((to),(from),(n))
661 * copy_from_user: - Copy a block of data from user space.
662 * @to: Destination address, in kernel space.
663 * @from: Source address, in user space.
664 * @n: Number of bytes to copy.
666 * Context: User context only. This function may sleep.
668 * Copy data from user space to kernel space.
670 * Returns number of bytes that could not be copied.
671 * On success, this will be zero.
673 * If some data could not be copied, this function will pad the copied
674 * data to the requested size using zero bytes.
676 #define copy_from_user(to,from,n) \
679 __generic_copy_from_user((to),(from),(n)); \
682 long __must_check
strncpy_from_user(char *dst
, const char __user
*src
,
684 long __must_check
__strncpy_from_user(char *dst
,
685 const char __user
*src
, long count
);
688 * __clear_user: - Zero a block of memory in user space, with less checking.
689 * @to: Destination address, in user space.
690 * @n: Number of bytes to zero.
692 * Zero a block of memory in user space. Caller must check
693 * the specified block with access_ok() before calling this function.
695 * Returns number of bytes that could not be cleared.
696 * On success, this will be zero.
698 unsigned long __clear_user(void __user
*mem
, unsigned long len
);
701 * clear_user: - Zero a block of memory in user space.
702 * @to: Destination address, in user space.
703 * @n: Number of bytes to zero.
705 * Zero a block of memory in user space. Caller must check
706 * the specified block with access_ok() before calling this function.
708 * Returns number of bytes that could not be cleared.
709 * On success, this will be zero.
711 unsigned long clear_user(void __user
*mem
, unsigned long len
);
714 * strlen_user: - Get the size of a string in user space.
715 * @str: The string to measure.
717 * Context: User context only. This function may sleep.
719 * Get the size of a NUL-terminated string in user space.
721 * Returns the size of the string INCLUDING the terminating NUL.
722 * On exception, returns 0.
724 * If there is a limit on the length of a valid string, you may wish to
725 * consider using strnlen_user() instead.
727 #define strlen_user(str) strnlen_user(str, ~0UL >> 1)
728 long strnlen_user(const char __user
*str
, long n
);
730 #endif /* _ASM_M32R_UACCESS_H */