Don't include linux/config.h from anywhere else in include/
[linux-2.6.git] / include / asm-m32r / uaccess.h
1 #ifndef _ASM_M32R_UACCESS_H
2 #define _ASM_M32R_UACCESS_H
3
4 /*
5  *  linux/include/asm-m32r/uaccess.h
6  *
7  *  M32R version.
8  *    Copyright (C) 2004, 2006  Hirokazu Takata <takata at linux-m32r.org>
9  */
10
11 /*
12  * User space memory access functions
13  */
14 #include <linux/errno.h>
15 #include <linux/thread_info.h>
16 #include <asm/page.h>
17
18 #define VERIFY_READ 0
19 #define VERIFY_WRITE 1
20
21 /*
22  * The fs value determines whether argument validity checking should be
23  * performed or not.  If get_fs() == USER_DS, checking is performed, with
24  * get_fs() == KERNEL_DS, checking is bypassed.
25  *
26  * For historical reasons, these macros are grossly misnamed.
27  */
28
29 #define MAKE_MM_SEG(s)  ((mm_segment_t) { (s) })
30
31 #ifdef CONFIG_MMU
32
33 #define KERNEL_DS       MAKE_MM_SEG(0xFFFFFFFF)
34 #define USER_DS         MAKE_MM_SEG(PAGE_OFFSET)
35 #define get_ds()        (KERNEL_DS)
36 #define get_fs()        (current_thread_info()->addr_limit)
37 #define set_fs(x)       (current_thread_info()->addr_limit = (x))
38
39 #else /* not CONFIG_MMU */
40
41 #define KERNEL_DS       MAKE_MM_SEG(0xFFFFFFFF)
42 #define USER_DS         MAKE_MM_SEG(0xFFFFFFFF)
43 #define get_ds()        (KERNEL_DS)
44
45 static inline mm_segment_t get_fs(void)
46 {
47         return USER_DS;
48 }
49
50 static inline void set_fs(mm_segment_t s)
51 {
52 }
53
54 #endif /* not CONFIG_MMU */
55
56 #define segment_eq(a,b) ((a).seg == (b).seg)
57
58 #define __addr_ok(addr) \
59         ((unsigned long)(addr) < (current_thread_info()->addr_limit.seg))
60
61 /*
62  * Test whether a block of memory is a valid user space address.
63  * Returns 0 if the range is valid, nonzero otherwise.
64  *
65  * This is equivalent to the following test:
66  * (u33)addr + (u33)size >= (u33)current->addr_limit.seg
67  *
68  * This needs 33-bit arithmetic. We have a carry...
69  */
70 #define __range_ok(addr,size) ({                                        \
71         unsigned long flag, sum;                                        \
72         __chk_user_ptr(addr);                                           \
73         asm (                                                           \
74                 "       cmpu    %1, %1    ; clear cbit\n"               \
75                 "       addx    %1, %3    ; set cbit if overflow\n"     \
76                 "       subx    %0, %0\n"                               \
77                 "       cmpu    %4, %1\n"                               \
78                 "       subx    %0, %5\n"                               \
79                 : "=&r" (flag), "=r" (sum)                              \
80                 : "1" (addr), "r" ((int)(size)),                        \
81                   "r" (current_thread_info()->addr_limit.seg), "r" (0)  \
82                 : "cbit" );                                             \
83         flag; })
84
85 /**
86  * access_ok: - Checks if a user space pointer is valid
87  * @type: Type of access: %VERIFY_READ or %VERIFY_WRITE.  Note that
88  *        %VERIFY_WRITE is a superset of %VERIFY_READ - if it is safe
89  *        to write to a block, it is always safe to read from it.
90  * @addr: User space pointer to start of block to check
91  * @size: Size of block to check
92  *
93  * Context: User context only.  This function may sleep.
94  *
95  * Checks if a pointer to a block of memory in user space is valid.
96  *
97  * Returns true (nonzero) if the memory block may be valid, false (zero)
98  * if it is definitely invalid.
99  *
100  * Note that, depending on architecture, this function probably just
101  * checks that the pointer is in the user space range - after calling
102  * this function, memory access functions may still return -EFAULT.
103  */
104 #ifdef CONFIG_MMU
105 #define access_ok(type,addr,size) (likely(__range_ok(addr,size) == 0))
106 #else
107 static inline int access_ok(int type, const void *addr, unsigned long size)
108 {
109         extern unsigned long memory_start, memory_end;
110         unsigned long val = (unsigned long)addr;
111
112         return ((val >= memory_start) && ((val + size) < memory_end));
113 }
114 #endif /* CONFIG_MMU */
115
116 /*
117  * The exception table consists of pairs of addresses: the first is the
118  * address of an instruction that is allowed to fault, and the second is
119  * the address at which the program should continue.  No registers are
120  * modified, so it is entirely up to the continuation code to figure out
121  * what to do.
122  *
123  * All the routines below use bits of fixup code that are out of line
124  * with the main instruction path.  This means when everything is well,
125  * we don't even have to jump over them.  Further, they do not intrude
126  * on our cache or tlb entries.
127  */
128
129 struct exception_table_entry
130 {
131         unsigned long insn, fixup;
132 };
133
134 extern int fixup_exception(struct pt_regs *regs);
135
136 /*
137  * These are the main single-value transfer routines.  They automatically
138  * use the right size if we just have the right pointer type.
139  *
140  * This gets kind of ugly. We want to return _two_ values in "get_user()"
141  * and yet we don't want to do any pointers, because that is too much
142  * of a performance impact. Thus we have a few rather ugly macros here,
143  * and hide all the uglyness from the user.
144  *
145  * The "__xxx" versions of the user access functions are versions that
146  * do not verify the address space, that must have been done previously
147  * with a separate "access_ok()" call (this is used when we do multiple
148  * accesses to the same area of user memory).
149  */
150
151 /* Careful: we have to cast the result to the type of the pointer for sign
152    reasons */
153 /**
154  * get_user: - Get a simple variable from user space.
155  * @x:   Variable to store result.
156  * @ptr: Source address, in user space.
157  *
158  * Context: User context only.  This function may sleep.
159  *
160  * This macro copies a single simple variable from user space to kernel
161  * space.  It supports simple types like char and int, but not larger
162  * data types like structures or arrays.
163  *
164  * @ptr must have pointer-to-simple-variable type, and the result of
165  * dereferencing @ptr must be assignable to @x without a cast.
166  *
167  * Returns zero on success, or -EFAULT on error.
168  * On error, the variable @x is set to zero.
169  */
170 #define get_user(x,ptr)                                                 \
171         __get_user_check((x),(ptr),sizeof(*(ptr)))
172
173 /**
174  * put_user: - Write a simple value into user space.
175  * @x:   Value to copy to user space.
176  * @ptr: Destination address, in user space.
177  *
178  * Context: User context only.  This function may sleep.
179  *
180  * This macro copies a single simple value from kernel space to user
181  * space.  It supports simple types like char and int, but not larger
182  * data types like structures or arrays.
183  *
184  * @ptr must have pointer-to-simple-variable type, and @x must be assignable
185  * to the result of dereferencing @ptr.
186  *
187  * Returns zero on success, or -EFAULT on error.
188  */
189 #define put_user(x,ptr)                                                 \
190         __put_user_check((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))
191
192 /**
193  * __get_user: - Get a simple variable from user space, with less checking.
194  * @x:   Variable to store result.
195  * @ptr: Source address, in user space.
196  *
197  * Context: User context only.  This function may sleep.
198  *
199  * This macro copies a single simple variable from user space to kernel
200  * space.  It supports simple types like char and int, but not larger
201  * data types like structures or arrays.
202  *
203  * @ptr must have pointer-to-simple-variable type, and the result of
204  * dereferencing @ptr must be assignable to @x without a cast.
205  *
206  * Caller must check the pointer with access_ok() before calling this
207  * function.
208  *
209  * Returns zero on success, or -EFAULT on error.
210  * On error, the variable @x is set to zero.
211  */
212 #define __get_user(x,ptr) \
213         __get_user_nocheck((x),(ptr),sizeof(*(ptr)))
214
215 #define __get_user_nocheck(x,ptr,size)                                  \
216 ({                                                                      \
217         long __gu_err = 0;                                              \
218         unsigned long __gu_val;                                         \
219         might_sleep();                                                  \
220         __get_user_size(__gu_val,(ptr),(size),__gu_err);                \
221         (x) = (__typeof__(*(ptr)))__gu_val;                             \
222         __gu_err;                                                       \
223 })
224
225 #define __get_user_check(x,ptr,size)                                    \
226 ({                                                                      \
227         long __gu_err = -EFAULT;                                        \
228         unsigned long __gu_val = 0;                                     \
229         const __typeof__(*(ptr)) __user *__gu_addr = (ptr);             \
230         might_sleep();                                                  \
231         if (access_ok(VERIFY_READ,__gu_addr,size))                      \
232                 __get_user_size(__gu_val,__gu_addr,(size),__gu_err);    \
233         (x) = (__typeof__(*(ptr)))__gu_val;                             \
234         __gu_err;                                                       \
235 })
236
237 extern long __get_user_bad(void);
238
239 #define __get_user_size(x,ptr,size,retval)                              \
240 do {                                                                    \
241         retval = 0;                                                     \
242         __chk_user_ptr(ptr);                                            \
243         switch (size) {                                                 \
244           case 1: __get_user_asm(x,ptr,retval,"ub"); break;             \
245           case 2: __get_user_asm(x,ptr,retval,"uh"); break;             \
246           case 4: __get_user_asm(x,ptr,retval,""); break;               \
247           default: (x) = __get_user_bad();                              \
248         }                                                               \
249 } while (0)
250
251 #define __get_user_asm(x, addr, err, itype)                             \
252         __asm__ __volatile__(                                           \
253                 "       .fillinsn\n"                                    \
254                 "1:     ld"itype" %1,@%2\n"                             \
255                 "       .fillinsn\n"                                    \
256                 "2:\n"                                                  \
257                 ".section .fixup,\"ax\"\n"                              \
258                 "       .balign 4\n"                                    \
259                 "3:     ldi %0,%3\n"                                    \
260                 "       seth r14,#high(2b)\n"                           \
261                 "       or3 r14,r14,#low(2b)\n"                         \
262                 "       jmp r14\n"                                      \
263                 ".previous\n"                                           \
264                 ".section __ex_table,\"a\"\n"                           \
265                 "       .balign 4\n"                                    \
266                 "       .long 1b,3b\n"                                  \
267                 ".previous"                                             \
268                 : "=&r" (err), "=&r" (x)                                \
269                 : "r" (addr), "i" (-EFAULT), "0" (err)                  \
270                 : "r14", "memory")
271
272 /**
273  * __put_user: - Write a simple value into user space, with less checking.
274  * @x:   Value to copy to user space.
275  * @ptr: Destination address, in user space.
276  *
277  * Context: User context only.  This function may sleep.
278  *
279  * This macro copies a single simple value from kernel space to user
280  * space.  It supports simple types like char and int, but not larger
281  * data types like structures or arrays.
282  *
283  * @ptr must have pointer-to-simple-variable type, and @x must be assignable
284  * to the result of dereferencing @ptr.
285  *
286  * Caller must check the pointer with access_ok() before calling this
287  * function.
288  *
289  * Returns zero on success, or -EFAULT on error.
290  */
291 #define __put_user(x,ptr) \
292         __put_user_nocheck((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))
293
294
295 #define __put_user_nocheck(x,ptr,size)                                  \
296 ({                                                                      \
297         long __pu_err;                                                  \
298         might_sleep();                                                  \
299         __put_user_size((x),(ptr),(size),__pu_err);                     \
300         __pu_err;                                                       \
301 })
302
303
304 #define __put_user_check(x,ptr,size)                                    \
305 ({                                                                      \
306         long __pu_err = -EFAULT;                                        \
307         __typeof__(*(ptr)) __user *__pu_addr = (ptr);                   \
308         might_sleep();                                                  \
309         if (access_ok(VERIFY_WRITE,__pu_addr,size))                     \
310                 __put_user_size((x),__pu_addr,(size),__pu_err);         \
311         __pu_err;                                                       \
312 })
313
314 #if defined(__LITTLE_ENDIAN__)
315 #define __put_user_u64(x, addr, err)                                    \
316         __asm__ __volatile__(                                           \
317                 "       .fillinsn\n"                                    \
318                 "1:     st %L1,@%2\n"                                   \
319                 "       .fillinsn\n"                                    \
320                 "2:     st %H1,@(4,%2)\n"                               \
321                 "       .fillinsn\n"                                    \
322                 "3:\n"                                                  \
323                 ".section .fixup,\"ax\"\n"                              \
324                 "       .balign 4\n"                                    \
325                 "4:     ldi %0,%3\n"                                    \
326                 "       seth r14,#high(3b)\n"                           \
327                 "       or3 r14,r14,#low(3b)\n"                         \
328                 "       jmp r14\n"                                      \
329                 ".previous\n"                                           \
330                 ".section __ex_table,\"a\"\n"                           \
331                 "       .balign 4\n"                                    \
332                 "       .long 1b,4b\n"                                  \
333                 "       .long 2b,4b\n"                                  \
334                 ".previous"                                             \
335                 : "=&r" (err)                                           \
336                 : "r" (x), "r" (addr), "i" (-EFAULT), "0" (err)         \
337                 : "r14", "memory")
338
339 #elif defined(__BIG_ENDIAN__)
340 #define __put_user_u64(x, addr, err)                                    \
341         __asm__ __volatile__(                                           \
342                 "       .fillinsn\n"                                    \
343                 "1:     st %H1,@%2\n"                                   \
344                 "       .fillinsn\n"                                    \
345                 "2:     st %L1,@(4,%2)\n"                               \
346                 "       .fillinsn\n"                                    \
347                 "3:\n"                                                  \
348                 ".section .fixup,\"ax\"\n"                              \
349                 "       .balign 4\n"                                    \
350                 "4:     ldi %0,%3\n"                                    \
351                 "       seth r14,#high(3b)\n"                           \
352                 "       or3 r14,r14,#low(3b)\n"                         \
353                 "       jmp r14\n"                                      \
354                 ".previous\n"                                           \
355                 ".section __ex_table,\"a\"\n"                           \
356                 "       .balign 4\n"                                    \
357                 "       .long 1b,4b\n"                                  \
358                 "       .long 2b,4b\n"                                  \
359                 ".previous"                                             \
360                 : "=&r" (err)                                           \
361                 : "r" (x), "r" (addr), "i" (-EFAULT), "0" (err)         \
362                 : "r14", "memory")
363 #else
364 #error no endian defined
365 #endif
366
367 extern void __put_user_bad(void);
368
369 #define __put_user_size(x,ptr,size,retval)                              \
370 do {                                                                    \
371         retval = 0;                                                     \
372         __chk_user_ptr(ptr);                                            \
373         switch (size) {                                                 \
374           case 1: __put_user_asm(x,ptr,retval,"b"); break;              \
375           case 2: __put_user_asm(x,ptr,retval,"h"); break;              \
376           case 4: __put_user_asm(x,ptr,retval,""); break;               \
377           case 8: __put_user_u64((__typeof__(*ptr))(x),ptr,retval); break;\
378           default: __put_user_bad();                                    \
379         }                                                               \
380 } while (0)
381
382 struct __large_struct { unsigned long buf[100]; };
383 #define __m(x) (*(struct __large_struct *)(x))
384
385 /*
386  * Tell gcc we read from memory instead of writing: this is because
387  * we do not write to any memory gcc knows about, so there are no
388  * aliasing issues.
389  */
390 #define __put_user_asm(x, addr, err, itype)                             \
391         __asm__ __volatile__(                                           \
392                 "       .fillinsn\n"                                    \
393                 "1:     st"itype" %1,@%2\n"                             \
394                 "       .fillinsn\n"                                    \
395                 "2:\n"                                                  \
396                 ".section .fixup,\"ax\"\n"                              \
397                 "       .balign 4\n"                                    \
398                 "3:     ldi %0,%3\n"                                    \
399                 "       seth r14,#high(2b)\n"                           \
400                 "       or3 r14,r14,#low(2b)\n"                         \
401                 "       jmp r14\n"                                      \
402                 ".previous\n"                                           \
403                 ".section __ex_table,\"a\"\n"                           \
404                 "       .balign 4\n"                                    \
405                 "       .long 1b,3b\n"                                  \
406                 ".previous"                                             \
407                 : "=&r" (err)                                           \
408                 : "r" (x), "r" (addr), "i" (-EFAULT), "0" (err)         \
409                 : "r14", "memory")
410
411 /*
412  * Here we special-case 1, 2 and 4-byte copy_*_user invocations.  On a fault
413  * we return the initial request size (1, 2 or 4), as copy_*_user should do.
414  * If a store crosses a page boundary and gets a fault, the m32r will not write
415  * anything, so this is accurate.
416  */
417
418 /*
419  * Copy To/From Userspace
420  */
421
422 /* Generic arbitrary sized copy.  */
423 /* Return the number of bytes NOT copied.  */
424 #define __copy_user(to,from,size)                                       \
425 do {                                                                    \
426         unsigned long __dst, __src, __c;                                \
427         __asm__ __volatile__ (                                          \
428                 "       mv      r14, %0\n"                              \
429                 "       or      r14, %1\n"                              \
430                 "       beq     %0, %1, 9f\n"                           \
431                 "       beqz    %2, 9f\n"                               \
432                 "       and3    r14, r14, #3\n"                         \
433                 "       bnez    r14, 2f\n"                              \
434                 "       and3    %2, %2, #3\n"                           \
435                 "       beqz    %3, 2f\n"                               \
436                 "       addi    %0, #-4         ; word_copy \n"         \
437                 "       .fillinsn\n"                                    \
438                 "0:     ld      r14, @%1+\n"                            \
439                 "       addi    %3, #-1\n"                              \
440                 "       .fillinsn\n"                                    \
441                 "1:     st      r14, @+%0\n"                            \
442                 "       bnez    %3, 0b\n"                               \
443                 "       beqz    %2, 9f\n"                               \
444                 "       addi    %0, #4\n"                               \
445                 "       .fillinsn\n"                                    \
446                 "2:     ldb     r14, @%1        ; byte_copy \n"         \
447                 "       .fillinsn\n"                                    \
448                 "3:     stb     r14, @%0\n"                             \
449                 "       addi    %1, #1\n"                               \
450                 "       addi    %2, #-1\n"                              \
451                 "       addi    %0, #1\n"                               \
452                 "       bnez    %2, 2b\n"                               \
453                 "       .fillinsn\n"                                    \
454                 "9:\n"                                                  \
455                 ".section .fixup,\"ax\"\n"                              \
456                 "       .balign 4\n"                                    \
457                 "5:     addi    %3, #1\n"                               \
458                 "       addi    %1, #-4\n"                              \
459                 "       .fillinsn\n"                                    \
460                 "6:     slli    %3, #2\n"                               \
461                 "       add     %2, %3\n"                               \
462                 "       addi    %0, #4\n"                               \
463                 "       .fillinsn\n"                                    \
464                 "7:     seth    r14, #high(9b)\n"                       \
465                 "       or3     r14, r14, #low(9b)\n"                   \
466                 "       jmp     r14\n"                                  \
467                 ".previous\n"                                           \
468                 ".section __ex_table,\"a\"\n"                           \
469                 "       .balign 4\n"                                    \
470                 "       .long 0b,6b\n"                                  \
471                 "       .long 1b,5b\n"                                  \
472                 "       .long 2b,9b\n"                                  \
473                 "       .long 3b,9b\n"                                  \
474                 ".previous\n"                                           \
475                 : "=&r" (__dst), "=&r" (__src), "=&r" (size),           \
476                   "=&r" (__c)                                           \
477                 : "0" (to), "1" (from), "2" (size), "3" (size / 4)      \
478                 : "r14", "memory");                                     \
479 } while (0)
480
481 #define __copy_user_zeroing(to,from,size)                               \
482 do {                                                                    \
483         unsigned long __dst, __src, __c;                                \
484         __asm__ __volatile__ (                                          \
485                 "       mv      r14, %0\n"                              \
486                 "       or      r14, %1\n"                              \
487                 "       beq     %0, %1, 9f\n"                           \
488                 "       beqz    %2, 9f\n"                               \
489                 "       and3    r14, r14, #3\n"                         \
490                 "       bnez    r14, 2f\n"                              \
491                 "       and3    %2, %2, #3\n"                           \
492                 "       beqz    %3, 2f\n"                               \
493                 "       addi    %0, #-4         ; word_copy \n"         \
494                 "       .fillinsn\n"                                    \
495                 "0:     ld      r14, @%1+\n"                            \
496                 "       addi    %3, #-1\n"                              \
497                 "       .fillinsn\n"                                    \
498                 "1:     st      r14, @+%0\n"                            \
499                 "       bnez    %3, 0b\n"                               \
500                 "       beqz    %2, 9f\n"                               \
501                 "       addi    %0, #4\n"                               \
502                 "       .fillinsn\n"                                    \
503                 "2:     ldb     r14, @%1        ; byte_copy \n"         \
504                 "       .fillinsn\n"                                    \
505                 "3:     stb     r14, @%0\n"                             \
506                 "       addi    %1, #1\n"                               \
507                 "       addi    %2, #-1\n"                              \
508                 "       addi    %0, #1\n"                               \
509                 "       bnez    %2, 2b\n"                               \
510                 "       .fillinsn\n"                                    \
511                 "9:\n"                                                  \
512                 ".section .fixup,\"ax\"\n"                              \
513                 "       .balign 4\n"                                    \
514                 "5:     addi    %3, #1\n"                               \
515                 "       addi    %1, #-4\n"                              \
516                 "       .fillinsn\n"                                    \
517                 "6:     slli    %3, #2\n"                               \
518                 "       add     %2, %3\n"                               \
519                 "       addi    %0, #4\n"                               \
520                 "       .fillinsn\n"                                    \
521                 "7:     ldi     r14, #0         ; store zero \n"        \
522                 "       .fillinsn\n"                                    \
523                 "8:     addi    %2, #-1\n"                              \
524                 "       stb     r14, @%0        ; ACE? \n"              \
525                 "       addi    %0, #1\n"                               \
526                 "       bnez    %2, 8b\n"                               \
527                 "       seth    r14, #high(9b)\n"                       \
528                 "       or3     r14, r14, #low(9b)\n"                   \
529                 "       jmp     r14\n"                                  \
530                 ".previous\n"                                           \
531                 ".section __ex_table,\"a\"\n"                           \
532                 "       .balign 4\n"                                    \
533                 "       .long 0b,6b\n"                                  \
534                 "       .long 1b,5b\n"                                  \
535                 "       .long 2b,7b\n"                                  \
536                 "       .long 3b,7b\n"                                  \
537                 ".previous\n"                                           \
538                 : "=&r" (__dst), "=&r" (__src), "=&r" (size),           \
539                   "=&r" (__c)                                           \
540                 : "0" (to), "1" (from), "2" (size), "3" (size / 4)      \
541                 : "r14", "memory");                                     \
542 } while (0)
543
544
545 /* We let the __ versions of copy_from/to_user inline, because they're often
546  * used in fast paths and have only a small space overhead.
547  */
548 static inline unsigned long __generic_copy_from_user_nocheck(void *to,
549         const void __user *from, unsigned long n)
550 {
551         __copy_user_zeroing(to,from,n);
552         return n;
553 }
554
555 static inline unsigned long __generic_copy_to_user_nocheck(void __user *to,
556         const void *from, unsigned long n)
557 {
558         __copy_user(to,from,n);
559         return n;
560 }
561
562 unsigned long __generic_copy_to_user(void __user *, const void *, unsigned long);
563 unsigned long __generic_copy_from_user(void *, const void __user *, unsigned long);
564
565 /**
566  * __copy_to_user: - Copy a block of data into user space, with less checking.
567  * @to:   Destination address, in user space.
568  * @from: Source address, in kernel space.
569  * @n:    Number of bytes to copy.
570  *
571  * Context: User context only.  This function may sleep.
572  *
573  * Copy data from kernel space to user space.  Caller must check
574  * the specified block with access_ok() before calling this function.
575  *
576  * Returns number of bytes that could not be copied.
577  * On success, this will be zero.
578  */
579 #define __copy_to_user(to,from,n)                       \
580         __generic_copy_to_user_nocheck((to),(from),(n))
581
582 #define __copy_to_user_inatomic __copy_to_user
583 #define __copy_from_user_inatomic __copy_from_user
584
585 /**
586  * copy_to_user: - Copy a block of data into user space.
587  * @to:   Destination address, in user space.
588  * @from: Source address, in kernel space.
589  * @n:    Number of bytes to copy.
590  *
591  * Context: User context only.  This function may sleep.
592  *
593  * Copy data from kernel space to user space.
594  *
595  * Returns number of bytes that could not be copied.
596  * On success, this will be zero.
597  */
598 #define copy_to_user(to,from,n)                         \
599 ({                                                      \
600         might_sleep();                                  \
601         __generic_copy_to_user((to),(from),(n));        \
602 })
603
604 /**
605  * __copy_from_user: - Copy a block of data from user space, with less checking. * @to:   Destination address, in kernel space.
606  * @from: Source address, in user space.
607  * @n:    Number of bytes to copy.
608  *
609  * Context: User context only.  This function may sleep.
610  *
611  * Copy data from user space to kernel space.  Caller must check
612  * the specified block with access_ok() before calling this function.
613  *
614  * Returns number of bytes that could not be copied.
615  * On success, this will be zero.
616  *
617  * If some data could not be copied, this function will pad the copied
618  * data to the requested size using zero bytes.
619  */
620 #define __copy_from_user(to,from,n)                     \
621         __generic_copy_from_user_nocheck((to),(from),(n))
622
623 /**
624  * copy_from_user: - Copy a block of data from user space.
625  * @to:   Destination address, in kernel space.
626  * @from: Source address, in user space.
627  * @n:    Number of bytes to copy.
628  *
629  * Context: User context only.  This function may sleep.
630  *
631  * Copy data from user space to kernel space.
632  *
633  * Returns number of bytes that could not be copied.
634  * On success, this will be zero.
635  *
636  * If some data could not be copied, this function will pad the copied
637  * data to the requested size using zero bytes.
638  */
639 #define copy_from_user(to,from,n)                       \
640 ({                                                      \
641         might_sleep();                                  \
642         __generic_copy_from_user((to),(from),(n));      \
643 })
644
645 long __must_check strncpy_from_user(char *dst, const char __user *src,
646                                 long count);
647 long __must_check __strncpy_from_user(char *dst,
648                                 const char __user *src, long count);
649
650 /**
651  * __clear_user: - Zero a block of memory in user space, with less checking.
652  * @to:   Destination address, in user space.
653  * @n:    Number of bytes to zero.
654  *
655  * Zero a block of memory in user space.  Caller must check
656  * the specified block with access_ok() before calling this function.
657  *
658  * Returns number of bytes that could not be cleared.
659  * On success, this will be zero.
660  */
661 unsigned long __clear_user(void __user *mem, unsigned long len);
662
663 /**
664  * clear_user: - Zero a block of memory in user space.
665  * @to:   Destination address, in user space.
666  * @n:    Number of bytes to zero.
667  *
668  * Zero a block of memory in user space.  Caller must check
669  * the specified block with access_ok() before calling this function.
670  *
671  * Returns number of bytes that could not be cleared.
672  * On success, this will be zero.
673  */
674 unsigned long clear_user(void __user *mem, unsigned long len);
675
676 /**
677  * strlen_user: - Get the size of a string in user space.
678  * @str: The string to measure.
679  *
680  * Context: User context only.  This function may sleep.
681  *
682  * Get the size of a NUL-terminated string in user space.
683  *
684  * Returns the size of the string INCLUDING the terminating NUL.
685  * On exception, returns 0.
686  *
687  * If there is a limit on the length of a valid string, you may wish to
688  * consider using strnlen_user() instead.
689  */
690 #define strlen_user(str) strnlen_user(str, ~0UL >> 1)
691 long strnlen_user(const char __user *str, long n);
692
693 #endif /* _ASM_M32R_UACCESS_H */