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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 | #ifndef __ASM_GENERIC_UACCESS_H
#define __ASM_GENERIC_UACCESS_H
/*
* User space memory access functions, these should work
* on a ny machine that has kernel and user data in the same
* address space, e.g. all NOMMU machines.
*/
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/string.h>
#include <asm/segment.h>
#define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
#ifndef KERNEL_DS
#define KERNEL_DS MAKE_MM_SEG(~0UL)
#endif
#ifndef USER_DS
#define USER_DS MAKE_MM_SEG(TASK_SIZE - 1)
#endif
#ifndef get_fs
#define get_ds() (KERNEL_DS)
#define get_fs() (current_thread_info()->addr_limit)
static inline void set_fs(mm_segment_t fs)
{
current_thread_info()->addr_limit = fs;
}
#endif
#define segment_eq(a, b) ((a).seg == (b).seg)
#define VERIFY_READ 0
#define VERIFY_WRITE 1
#define access_ok(type, addr, size) __access_ok((unsigned long)(addr),(size))
/*
* The architecture should really override this if possible, at least
* doing a check on the get_fs()
*/
#ifndef __access_ok
static inline int __access_ok(unsigned long addr, unsigned long size)
{
return 1;
}
#endif
/*
* The exception table consists of pairs of addresses: the first is the
* address of an instruction that is allowed to fault, and the second is
* the address at which the program should continue. No registers are
* modified, so it is entirely up to the continuation code to figure out
* what to do.
*
* All the routines below use bits of fixup code that are out of line
* with the main instruction path. This means when everything is well,
* we don't even have to jump over them. Further, they do not intrude
* on our cache or tlb entries.
*/
struct exception_table_entry
{
unsigned long insn, fixup;
};
/* Returns 0 if exception not found and fixup otherwise. */
extern unsigned long search_exception_table(unsigned long);
/*
* architectures with an MMU should override these two
*/
#ifndef __copy_from_user
static inline __must_check long __copy_from_user(void *to,
const void __user * from, unsigned long n)
{
if (__builtin_constant_p(n)) {
switch(n) {
case 1:
*(u8 *)to = *(u8 __force *)from;
return 0;
case 2:
*(u16 *)to = *(u16 __force *)from;
return 0;
case 4:
*(u32 *)to = *(u32 __force *)from;
return 0;
#ifdef CONFIG_64BIT
case 8:
*(u64 *)to = *(u64 __force *)from;
return 0;
#endif
default:
break;
}
}
memcpy(to, (const void __force *)from, n);
return 0;
}
#endif
#ifndef __copy_to_user
static inline __must_check long __copy_to_user(void __user *to,
const void *from, unsigned long n)
{
if (__builtin_constant_p(n)) {
switch(n) {
case 1:
*(u8 __force *)to = *(u8 *)from;
return 0;
case 2:
*(u16 __force *)to = *(u16 *)from;
return 0;
case 4:
*(u32 __force *)to = *(u32 *)from;
return 0;
#ifdef CONFIG_64BIT
case 8:
*(u64 __force *)to = *(u64 *)from;
return 0;
#endif
default:
break;
}
}
memcpy((void __force *)to, from, n);
return 0;
}
#endif
/*
* These are the main single-value transfer routines. They automatically
* use the right size if we just have the right pointer type.
* This version just falls back to copy_{from,to}_user, which should
* provide a fast-path for small values.
*/
#define __put_user(x, ptr) \
({ \
__typeof__(*(ptr)) __x = (x); \
int __pu_err = -EFAULT; \
__chk_user_ptr(ptr); \
switch (sizeof (*(ptr))) { \
case 1: \
case 2: \
case 4: \
case 8: \
__pu_err = __put_user_fn(sizeof (*(ptr)), \
ptr, &__x); \
break; \
default: \
__put_user_bad(); \
break; \
} \
__pu_err; \
})
#define put_user(x, ptr) \
({ \
might_sleep(); \
access_ok(VERIFY_WRITE, ptr, sizeof(*ptr)) ? \
__put_user(x, ptr) : \
-EFAULT; \
})
static inline int __put_user_fn(size_t size, void __user *ptr, void *x)
{
size = __copy_to_user(ptr, x, size);
return size ? -EFAULT : size;
}
extern int __put_user_bad(void) __attribute__((noreturn));
#define __get_user(x, ptr) \
({ \
int __gu_err = -EFAULT; \
__chk_user_ptr(ptr); \
switch (sizeof(*(ptr))) { \
case 1: { \
unsigned char __x; \
__gu_err = __get_user_fn(sizeof (*(ptr)), \
ptr, &__x); \
(x) = *(__force __typeof__(*(ptr)) *) &__x; \
break; \
}; \
case 2: { \
unsigned short __x; \
__gu_err = __get_user_fn(sizeof (*(ptr)), \
ptr, &__x); \
(x) = *(__force __typeof__(*(ptr)) *) &__x; \
break; \
}; \
case 4: { \
unsigned int __x; \
__gu_err = __get_user_fn(sizeof (*(ptr)), \
ptr, &__x); \
(x) = *(__force __typeof__(*(ptr)) *) &__x; \
break; \
}; \
case 8: { \
unsigned long long __x; \
__gu_err = __get_user_fn(sizeof (*(ptr)), \
ptr, &__x); \
(x) = *(__force __typeof__(*(ptr)) *) &__x; \
break; \
}; \
default: \
__get_user_bad(); \
break; \
} \
__gu_err; \
})
#define get_user(x, ptr) \
({ \
might_sleep(); \
access_ok(VERIFY_READ, ptr, sizeof(*ptr)) ? \
__get_user(x, ptr) : \
-EFAULT; \
})
static inline int __get_user_fn(size_t size, const void __user *ptr, void *x)
{
size = __copy_from_user(x, ptr, size);
return size ? -EFAULT : size;
}
extern int __get_user_bad(void) __attribute__((noreturn));
#ifndef __copy_from_user_inatomic
#define __copy_from_user_inatomic __copy_from_user
#endif
#ifndef __copy_to_user_inatomic
#define __copy_to_user_inatomic __copy_to_user
#endif
static inline long copy_from_user(void *to,
const void __user * from, unsigned long n)
{
might_sleep();
if (access_ok(VERIFY_READ, from, n))
return __copy_from_user(to, from, n);
else
return n;
}
static inline long copy_to_user(void __user *to,
const void *from, unsigned long n)
{
might_sleep();
if (access_ok(VERIFY_WRITE, to, n))
return __copy_to_user(to, from, n);
else
return n;
}
/*
* Copy a null terminated string from userspace.
*/
#ifndef __strncpy_from_user
static inline long
__strncpy_from_user(char *dst, const char __user *src, long count)
{
char *tmp;
strncpy(dst, (const char __force *)src, count);
for (tmp = dst; *tmp && count > 0; tmp++, count--)
;
return (tmp - dst);
}
#endif
static inline long
strncpy_from_user(char *dst, const char __user *src, long count)
{
if (!access_ok(VERIFY_READ, src, 1))
return -EFAULT;
return __strncpy_from_user(dst, src, count);
}
/*
* Return the size of a string (including the ending 0)
*
* Return 0 on exception, a value greater than N if too long
*/
#ifndef strnlen_user
static inline long strnlen_user(const char __user *src, long n)
{
if (!access_ok(VERIFY_READ, src, 1))
return 0;
return strlen((void * __force)src) + 1;
}
#endif
static inline long strlen_user(const char __user *src)
{
return strnlen_user(src, 32767);
}
/*
* Zero Userspace
*/
#ifndef __clear_user
static inline __must_check unsigned long
__clear_user(void __user *to, unsigned long n)
{
memset((void __force *)to, 0, n);
return 0;
}
#endif
static inline __must_check unsigned long
clear_user(void __user *to, unsigned long n)
{
might_sleep();
if (!access_ok(VERIFY_WRITE, to, n))
return n;
return __clear_user(to, n);
}
#endif /* __ASM_GENERIC_UACCESS_H */
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