1 /* MN10300 userspace access functions
3 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public Licence
8 * as published by the Free Software Foundation; either version
9 * 2 of the Licence, or (at your option) any later version.
11 #ifndef _ASM_UACCESS_H
12 #define _ASM_UACCESS_H
15 * User space memory access functions
17 #include <linux/sched.h>
19 #include <asm/pgtable.h>
20 #include <asm/errno.h>
23 #define VERIFY_WRITE 1
26 * The fs value determines whether argument validity checking should be
27 * performed or not. If get_fs() == USER_DS, checking is performed, with
28 * get_fs() == KERNEL_DS, checking is bypassed.
30 * For historical reasons, these macros are grossly misnamed.
33 #define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
35 #define KERNEL_XDS MAKE_MM_SEG(0xBFFFFFFF)
36 #define KERNEL_DS MAKE_MM_SEG(0x9FFFFFFF)
37 #define USER_DS MAKE_MM_SEG(TASK_SIZE)
39 #define get_ds() (KERNEL_DS)
40 #define get_fs() (current_thread_info()->addr_limit)
41 #define set_fs(x) (current_thread_info()->addr_limit = (x))
42 #define __kernel_ds_p() (current_thread_info()->addr_limit.seg == 0x9FFFFFFF)
44 #define segment_eq(a, b) ((a).seg == (b).seg)
46 #define __addr_ok(addr) \
47 ((unsigned long)(addr) < (current_thread_info()->addr_limit.seg))
50 * check that a range of addresses falls within the current address limit
52 static inline int ___range_ok(unsigned long addr
, unsigned int size
)
56 asm(" add %3,%1 \n" /* set C-flag if addr + size > 4Gb */
58 " cmp %4,%1 \n" /* jump if addr+size>limit (error) */
60 " clr %0 \n" /* mark okay */
62 : "=r"(flag
), "=&r"(tmp
)
63 : "1"(addr
), "ir"(size
),
64 "r"(current_thread_info()->addr_limit
.seg
), "0"(flag
)
71 #define __range_ok(addr, size) ___range_ok((unsigned long)(addr), (u32)(size))
73 #define access_ok(type, addr, size) (__range_ok((addr), (size)) == 0)
74 #define __access_ok(addr, size) (__range_ok((addr), (size)) == 0)
76 static inline int verify_area(int type
, const void *addr
, unsigned long size
)
78 return access_ok(type
, addr
, size
) ? 0 : -EFAULT
;
83 * The exception table consists of pairs of addresses: the first is the
84 * address of an instruction that is allowed to fault, and the second is
85 * the address at which the program should continue. No registers are
86 * modified, so it is entirely up to the continuation code to figure out
89 * All the routines below use bits of fixup code that are out of line
90 * with the main instruction path. This means when everything is well,
91 * we don't even have to jump over them. Further, they do not intrude
92 * on our cache or tlb entries.
95 struct exception_table_entry
97 unsigned long insn
, fixup
;
100 /* Returns 0 if exception not found and fixup otherwise. */
101 extern int fixup_exception(struct pt_regs
*regs
);
103 #define put_user(x, ptr) __put_user_check((x), (ptr), sizeof(*(ptr)))
104 #define get_user(x, ptr) __get_user_check((x), (ptr), sizeof(*(ptr)))
107 * The "__xxx" versions do not do address space checking, useful when
108 * doing multiple accesses to the same area (the user has to do the
109 * checks by hand with "access_ok()")
111 #define __put_user(x, ptr) __put_user_nocheck((x), (ptr), sizeof(*(ptr)))
112 #define __get_user(x, ptr) __get_user_nocheck((x), (ptr), sizeof(*(ptr)))
115 * The "xxx_ret" versions return constant specified in third argument, if
116 * something bad happens. These macros can be optimized for the
117 * case of just returning from the function xxx_ret is used.
120 #define put_user_ret(x, ptr, ret) \
121 ({ if (put_user((x), (ptr))) return (ret); })
122 #define get_user_ret(x, ptr, ret) \
123 ({ if (get_user((x), (ptr))) return (ret); })
124 #define __put_user_ret(x, ptr, ret) \
125 ({ if (__put_user((x), (ptr))) return (ret); })
126 #define __get_user_ret(x, ptr, ret) \
127 ({ if (__get_user((x), (ptr))) return (ret); })
129 struct __large_struct
{ unsigned long buf
[100]; };
130 #define __m(x) (*(struct __large_struct *)(x))
132 #define __get_user_nocheck(x, ptr, size) \
134 __typeof(*(ptr)) __gu_val; \
135 unsigned long __gu_addr; \
137 __gu_addr = (unsigned long) (ptr); \
139 case 1: __get_user_asm("bu"); break; \
140 case 2: __get_user_asm("hu"); break; \
141 case 4: __get_user_asm("" ); break; \
142 default: __get_user_unknown(); break; \
144 x = (__typeof__(*(ptr))) __gu_val; \
148 #define __get_user_check(x, ptr, size) \
150 __typeof__(*(ptr)) __gu_val; \
151 unsigned long __gu_addr; \
153 __gu_addr = (unsigned long) (ptr); \
154 if (likely(__access_ok(__gu_addr,size))) { \
156 case 1: __get_user_asm("bu"); break; \
157 case 2: __get_user_asm("hu"); break; \
158 case 4: __get_user_asm("" ); break; \
159 default: __get_user_unknown(); break; \
163 __gu_err = -EFAULT; \
166 x = (__typeof__(*(ptr))) __gu_val; \
170 #define __get_user_asm(INSN) \
174 " mov"INSN" %2,%1\n" \
177 " .section .fixup,\"ax\"\n" \
182 " .section __ex_table,\"a\"\n" \
186 : "=&r" (__gu_err), "=&r" (__gu_val) \
187 : "m" (__m(__gu_addr)), "i" (-EFAULT)); \
190 extern int __get_user_unknown(void);
192 #define __put_user_nocheck(x, ptr, size) \
195 __typeof__(*(ptr)) val; \
198 unsigned long __pu_addr; \
200 __pu_val.val = (x); \
201 __pu_addr = (unsigned long) (ptr); \
203 case 1: __put_user_asm("bu"); break; \
204 case 2: __put_user_asm("hu"); break; \
205 case 4: __put_user_asm("" ); break; \
206 case 8: __put_user_asm8(); break; \
207 default: __pu_err = __put_user_unknown(); break; \
212 #define __put_user_check(x, ptr, size) \
215 __typeof__(*(ptr)) val; \
218 unsigned long __pu_addr; \
220 __pu_val.val = (x); \
221 __pu_addr = (unsigned long) (ptr); \
222 if (likely(__access_ok(__pu_addr, size))) { \
224 case 1: __put_user_asm("bu"); break; \
225 case 2: __put_user_asm("hu"); break; \
226 case 4: __put_user_asm("" ); break; \
227 case 8: __put_user_asm8(); break; \
228 default: __pu_err = __put_user_unknown(); break; \
232 __pu_err = -EFAULT; \
237 #define __put_user_asm(INSN) \
241 " mov"INSN" %1,%2\n" \
244 " .section .fixup,\"ax\"\n" \
249 " .section __ex_table,\"a\"\n" \
254 : "r" (__pu_val.val), "m" (__m(__pu_addr)), \
259 #define __put_user_asm8() \
266 " .section .fixup,\"ax\" \n" \
271 " .section __ex_table,\"a\"\n" \
277 : "r" (__pu_val.bits[0]), "r" (__pu_val.bits[1]), \
278 "m" (__m(__pu_addr)), "m" (__m(__pu_addr+4)), \
283 extern int __put_user_unknown(void);
287 * Copy To/From Userspace
289 /* Generic arbitrary sized copy. */
290 #define __copy_user(to, from, size) \
294 const void *__from = from; \
297 "0: movbu (%0),%3;\n" \
298 "1: movbu %3,(%1);\n" \
304 " .section .fixup,\"ax\"\n" \
307 " .section __ex_table,\"a\"\n" \
312 : "=a"(__from), "=a"(__to), "=r"(size), "=&r"(w)\
313 : "0"(__from), "1"(__to), "2"(size) \
318 #define __copy_user_zeroing(to, from, size) \
322 const void *__from = from; \
325 "0: movbu (%0),%3;\n" \
326 "1: movbu %3,(%1);\n" \
332 " .section .fixup,\"ax\"\n" \
336 "4: movbu %3,(%1);\n" \
343 " .section __ex_table,\"a\"\n" \
348 : "=a"(__from), "=a"(__to), "=r"(size), "=&r"(w)\
349 : "0"(__from), "1"(__to), "2"(size) \
354 /* We let the __ versions of copy_from/to_user inline, because they're often
355 * used in fast paths and have only a small space overhead.
358 unsigned long __generic_copy_from_user_nocheck(void *to
, const void *from
,
361 __copy_user_zeroing(to
, from
, n
);
366 unsigned long __generic_copy_to_user_nocheck(void *to
, const void *from
,
369 __copy_user(to
, from
, n
);
375 #error don't use - these macros don't increment to & from pointers
376 /* Optimize just a little bit when we know the size of the move. */
377 #define __constant_copy_user(to, from, size) \
381 "0: movbu (%1),d3;\n" \
382 "1: movbu d3,(%2);\n" \
386 ".section .fixup,\"ax\"\n" \
389 ".section __ex_table,\"a\"\n" \
395 : "d"(size), "d"(to), "d"(from) \
399 /* Optimize just a little bit when we know the size of the move. */
400 #define __constant_copy_user_zeroing(to, from, size) \
404 "0: movbu (%1),d3;\n" \
405 "1: movbu d3,(%2);\n" \
409 ".section .fixup,\"ax\"\n" \
412 ".section __ex_table,\"a\"\n" \
418 : "d"(size), "d"(to), "d"(from) \
423 unsigned long __constant_copy_to_user(void *to
, const void *from
,
426 if (access_ok(VERIFY_WRITE
, to
, n
))
427 __constant_copy_user(to
, from
, n
);
432 unsigned long __constant_copy_from_user(void *to
, const void *from
,
435 if (access_ok(VERIFY_READ
, from
, n
))
436 __constant_copy_user_zeroing(to
, from
, n
);
441 unsigned long __constant_copy_to_user_nocheck(void *to
, const void *from
,
444 __constant_copy_user(to
, from
, n
);
449 unsigned long __constant_copy_from_user_nocheck(void *to
, const void *from
,
452 __constant_copy_user_zeroing(to
, from
, n
);
457 extern unsigned long __generic_copy_to_user(void __user
*, const void *,
459 extern unsigned long __generic_copy_from_user(void *, const void __user
*,
462 #define __copy_to_user_inatomic(to, from, n) \
463 __generic_copy_to_user_nocheck((to), (from), (n))
464 #define __copy_from_user_inatomic(to, from, n) \
465 __generic_copy_from_user_nocheck((to), (from), (n))
467 #define __copy_to_user(to, from, n) \
470 __copy_to_user_inatomic((to), (from), (n)); \
473 #define __copy_from_user(to, from, n) \
476 __copy_from_user_inatomic((to), (from), (n)); \
480 #define copy_to_user(to, from, n) __generic_copy_to_user((to), (from), (n))
481 #define copy_from_user(to, from, n) __generic_copy_from_user((to), (from), (n))
483 extern long strncpy_from_user(char *dst
, const char __user
*src
, long count
);
484 extern long __strncpy_from_user(char *dst
, const char __user
*src
, long count
);
485 extern long strnlen_user(const char __user
*str
, long n
);
486 #define strlen_user(str) strnlen_user(str, ~0UL >> 1)
487 extern unsigned long clear_user(void __user
*mem
, unsigned long len
);
488 extern unsigned long __clear_user(void __user
*mem
, unsigned long len
);
490 #endif /* _ASM_UACCESS_H */