1 /* uaccess.h: userspace accessor functions
3 * Copyright (C) 2004 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 License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
12 #ifndef _ASM_UACCESS_H
13 #define _ASM_UACCESS_H
16 * User space memory access functions
18 #include <linux/sched.h>
20 #include <asm/segment.h>
21 #include <asm/sections.h>
23 #define HAVE_ARCH_UNMAPPED_AREA /* we decide where to put mmaps */
25 #define __ptr(x) ((unsigned long __force *)(x))
28 #define VERIFY_WRITE 1
30 #define __addr_ok(addr) ((unsigned long)(addr) < get_addr_limit())
33 * check that a range of addresses falls within the current address limit
35 static inline int ___range_ok(unsigned long addr
, unsigned long size
)
38 int flag
= -EFAULT
, tmp
;
41 " addcc %3,%2,%1,icc0 \n" /* set C-flag if addr+size>4GB */
42 " subcc.p %1,%4,gr0,icc1 \n" /* jump if addr+size>limit */
45 " setlos #0,%0 \n" /* mark okay */
47 : "=r"(flag
), "=&r"(tmp
)
48 : "r"(addr
), "r"(size
), "r"(get_addr_limit()), "0"(flag
)
55 if (addr
< memory_start
||
57 size
> memory_end
- memory_start
||
58 addr
+ size
> memory_end
)
65 #define __range_ok(addr,size) ___range_ok((unsigned long) (addr), (unsigned long) (size))
67 #define access_ok(type,addr,size) (__range_ok((void __user *)(addr), (size)) == 0)
68 #define __access_ok(addr,size) (__range_ok((addr), (size)) == 0)
71 * The exception table consists of pairs of addresses: the first is the
72 * address of an instruction that is allowed to fault, and the second is
73 * the address at which the program should continue. No registers are
74 * modified, so it is entirely up to the continuation code to figure out
77 * All the routines below use bits of fixup code that are out of line
78 * with the main instruction path. This means when everything is well,
79 * we don't even have to jump over them. Further, they do not intrude
80 * on our cache or tlb entries.
82 struct exception_table_entry
84 unsigned long insn
, fixup
;
87 /* Returns 0 if exception not found and fixup otherwise. */
88 extern unsigned long search_exception_table(unsigned long);
92 * These are the main single-value transfer routines. They automatically
93 * use the right size if we just have the right pointer type.
95 #define __put_user(x, ptr) \
99 typeof(*(ptr)) __pu_val = (x); \
100 __chk_user_ptr(ptr); \
102 switch (sizeof (*(ptr))) { \
104 __put_user_asm(__pu_err, __pu_val, ptr, "b", "r"); \
107 __put_user_asm(__pu_err, __pu_val, ptr, "h", "r"); \
110 __put_user_asm(__pu_err, __pu_val, ptr, "", "r"); \
113 __put_user_asm(__pu_err, __pu_val, ptr, "d", "e"); \
116 __pu_err = __put_user_bad(); \
122 #define put_user(x, ptr) \
124 typeof(*(ptr)) __user *_p = (ptr); \
127 _e = __range_ok(_p, sizeof(*_p)); \
129 _e = __put_user((x), _p); \
133 extern int __put_user_bad(void);
136 * Tell gcc we read from memory instead of writing: this is because
137 * we do not write to any memory gcc knows about, so there are no
143 #define __put_user_asm(err,x,ptr,dsize,constraint) \
145 asm volatile("1: st"dsize"%I1 %2,%M1 \n" \
148 "3: setlos %3,%0 \n" \
151 ".section __ex_table,\"a\" \n" \
156 : "m" (*__ptr(ptr)), constraint (x), "i"(-EFAULT), "0"(err) \
162 #define __put_user_asm(err,x,ptr,bwl,con) \
164 asm(" st"bwl"%I0 %1,%M0 \n" \
167 : "m" (*__ptr(ptr)), con (x) \
173 /*****************************************************************************/
177 #define __get_user(x, ptr) \
180 __chk_user_ptr(ptr); \
182 switch (sizeof(*(ptr))) { \
184 unsigned char __gu_val; \
185 __get_user_asm(__gu_err, __gu_val, ptr, "ub", "=r"); \
186 (x) = *(__force __typeof__(*(ptr)) *) &__gu_val; \
190 unsigned short __gu_val; \
191 __get_user_asm(__gu_err, __gu_val, ptr, "uh", "=r"); \
192 (x) = *(__force __typeof__(*(ptr)) *) &__gu_val; \
196 unsigned int __gu_val; \
197 __get_user_asm(__gu_err, __gu_val, ptr, "", "=r"); \
198 (x) = *(__force __typeof__(*(ptr)) *) &__gu_val; \
202 unsigned long long __gu_val; \
203 __get_user_asm(__gu_err, __gu_val, ptr, "d", "=e"); \
204 (x) = *(__force __typeof__(*(ptr)) *) &__gu_val; \
208 __gu_err = __get_user_bad(); \
214 #define get_user(x, ptr) \
216 const typeof(*(ptr)) __user *_p = (ptr);\
219 _e = __range_ok(_p, sizeof(*_p)); \
220 if (likely(_e == 0)) \
221 _e = __get_user((x), _p); \
223 (x) = (typeof(x)) 0; \
227 extern int __get_user_bad(void);
231 #define __get_user_asm(err,x,ptr,dtype,constraint) \
233 asm("1: ld"dtype"%I2 %M2,%1 \n" \
236 "3: setlos %3,%0 \n" \
240 ".section __ex_table,\"a\" \n" \
244 : "=r" (err), constraint (x) \
245 : "m" (*__ptr(ptr)), "i"(-EFAULT), "0"(err) \
251 #define __get_user_asm(err,x,ptr,bwl,con) \
252 asm(" ld"bwl"%I1 %M1,%0 \n" \
259 /*****************************************************************************/
263 #define ____force(x) (__force void *)(void __user *)(x)
265 extern long __memset_user(void *dst
, unsigned long count
);
266 extern long __memcpy_user(void *dst
, const void *src
, unsigned long count
);
268 #define clear_user(dst,count) __memset_user(____force(dst), (count))
269 #define __copy_from_user_inatomic(to, from, n) __memcpy_user((to), ____force(from), (n))
270 #define __copy_to_user_inatomic(to, from, n) __memcpy_user(____force(to), (from), (n))
274 #define clear_user(dst,count) (memset(____force(dst), 0, (count)), 0)
275 #define __copy_from_user_inatomic(to, from, n) (memcpy((to), ____force(from), (n)), 0)
276 #define __copy_to_user_inatomic(to, from, n) (memcpy(____force(to), (from), (n)), 0)
280 static inline unsigned long __must_check
281 __copy_to_user(void __user
*to
, const void *from
, unsigned long n
)
284 return __copy_to_user_inatomic(to
, from
, n
);
287 static inline unsigned long
288 __copy_from_user(void *to
, const void __user
*from
, unsigned long n
)
291 return __copy_from_user_inatomic(to
, from
, n
);
294 static inline long copy_from_user(void *to
, const void __user
*from
, unsigned long n
)
296 unsigned long ret
= n
;
298 if (likely(__access_ok(from
, n
)))
299 ret
= __copy_from_user(to
, from
, n
);
301 if (unlikely(ret
!= 0))
302 memset(to
+ (n
- ret
), 0, ret
);
307 static inline long copy_to_user(void __user
*to
, const void *from
, unsigned long n
)
309 return likely(__access_ok(to
, n
)) ? __copy_to_user(to
, from
, n
) : n
;
312 extern long strncpy_from_user(char *dst
, const char __user
*src
, long count
);
313 extern long strnlen_user(const char __user
*src
, long count
);
315 #define strlen_user(str) strnlen_user(str, 32767)
317 extern unsigned long search_exception_table(unsigned long addr
);
319 #endif /* _ASM_UACCESS_H */