2 * include/asm-s390/uaccess.h
5 * Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation
6 * Author(s): Hartmut Penner (hp@de.ibm.com),
7 * Martin Schwidefsky (schwidefsky@de.ibm.com)
9 * Derived from "include/asm-i386/uaccess.h"
11 #ifndef __S390_UACCESS_H
12 #define __S390_UACCESS_H
15 * User space memory access functions
17 #include <linux/sched.h>
18 #include <linux/errno.h>
21 #define VERIFY_WRITE 1
25 * The fs value determines whether argument validity checking should be
26 * performed or not. If get_fs() == USER_DS, checking is performed, with
27 * get_fs() == KERNEL_DS, checking is bypassed.
29 * For historical reasons, these macros are grossly misnamed.
32 #define MAKE_MM_SEG(a) ((mm_segment_t) { (a) })
35 #define KERNEL_DS MAKE_MM_SEG(0)
36 #define USER_DS MAKE_MM_SEG(1)
38 #define get_ds() (KERNEL_DS)
39 #define get_fs() (current->thread.mm_segment)
44 unsigned long __pto; \
45 current->thread.mm_segment = (x); \
46 __pto = current->thread.mm_segment.ar4 ? \
47 S390_lowcore.user_asce : S390_lowcore.kernel_asce; \
48 asm volatile ("lctlg 7,7,%0" : : "m" (__pto) ); \
53 unsigned long __pto; \
54 current->thread.mm_segment = (x); \
55 __pto = current->thread.mm_segment.ar4 ? \
56 S390_lowcore.user_asce : S390_lowcore.kernel_asce; \
57 asm volatile ("lctl 7,7,%0" : : "m" (__pto) ); \
59 #endif /* __s390x__ */
61 #define segment_eq(a,b) ((a).ar4 == (b).ar4)
64 static inline int __access_ok(const void __user
*addr
, unsigned long size
)
68 #define access_ok(type,addr,size) __access_ok(addr,size)
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.
83 struct exception_table_entry
85 unsigned long insn
, fixup
;
89 size_t (*copy_from_user
)(size_t, const void __user
*, void *);
90 size_t (*copy_from_user_small
)(size_t, const void __user
*, void *);
91 size_t (*copy_to_user
)(size_t, void __user
*, const void *);
92 size_t (*copy_to_user_small
)(size_t, void __user
*, const void *);
93 size_t (*copy_in_user
)(size_t, void __user
*, const void __user
*);
94 size_t (*clear_user
)(size_t, void __user
*);
95 size_t (*strnlen_user
)(size_t, const char __user
*);
96 size_t (*strncpy_from_user
)(size_t, const char __user
*, char *);
97 int (*futex_atomic_op
)(int op
, int __user
*, int oparg
, int *old
);
98 int (*futex_atomic_cmpxchg
)(int __user
*, int old
, int new);
101 extern struct uaccess_ops uaccess
;
102 extern struct uaccess_ops uaccess_std
;
103 extern struct uaccess_ops uaccess_mvcos
;
105 static inline int __put_user_fn(size_t size
, void __user
*ptr
, void *x
)
107 size
= uaccess
.copy_to_user_small(size
, ptr
, x
);
108 return size
? -EFAULT
: size
;
111 static inline int __get_user_fn(size_t size
, const void __user
*ptr
, void *x
)
113 size
= uaccess
.copy_from_user_small(size
, ptr
, x
);
114 return size
? -EFAULT
: size
;
118 * These are the main single-value transfer routines. They automatically
119 * use the right size if we just have the right pointer type.
121 #define __put_user(x, ptr) \
123 __typeof__(*(ptr)) __x = (x); \
124 int __pu_err = -EFAULT; \
125 __chk_user_ptr(ptr); \
126 switch (sizeof (*(ptr))) { \
131 __pu_err = __put_user_fn(sizeof (*(ptr)), \
141 #define put_user(x, ptr) \
144 __put_user(x, ptr); \
148 extern int __put_user_bad(void) __attribute__((noreturn
));
150 #define __get_user(x, ptr) \
152 int __gu_err = -EFAULT; \
153 __chk_user_ptr(ptr); \
154 switch (sizeof(*(ptr))) { \
157 __gu_err = __get_user_fn(sizeof (*(ptr)), \
159 (x) = *(__force __typeof__(*(ptr)) *) &__x; \
163 unsigned short __x; \
164 __gu_err = __get_user_fn(sizeof (*(ptr)), \
166 (x) = *(__force __typeof__(*(ptr)) *) &__x; \
171 __gu_err = __get_user_fn(sizeof (*(ptr)), \
173 (x) = *(__force __typeof__(*(ptr)) *) &__x; \
177 unsigned long long __x; \
178 __gu_err = __get_user_fn(sizeof (*(ptr)), \
180 (x) = *(__force __typeof__(*(ptr)) *) &__x; \
190 #define get_user(x, ptr) \
193 __get_user(x, ptr); \
196 extern int __get_user_bad(void) __attribute__((noreturn
));
198 #define __put_user_unaligned __put_user
199 #define __get_user_unaligned __get_user
202 * __copy_to_user: - Copy a block of data into user space, with less checking.
203 * @to: Destination address, in user space.
204 * @from: Source address, in kernel space.
205 * @n: Number of bytes to copy.
207 * Context: User context only. This function may sleep.
209 * Copy data from kernel space to user space. Caller must check
210 * the specified block with access_ok() before calling this function.
212 * Returns number of bytes that could not be copied.
213 * On success, this will be zero.
215 static inline unsigned long
216 __copy_to_user(void __user
*to
, const void *from
, unsigned long n
)
218 if (__builtin_constant_p(n
) && (n
<= 256))
219 return uaccess
.copy_to_user_small(n
, to
, from
);
221 return uaccess
.copy_to_user(n
, to
, from
);
224 #define __copy_to_user_inatomic __copy_to_user
225 #define __copy_from_user_inatomic __copy_from_user
228 * copy_to_user: - Copy a block of data into user space.
229 * @to: Destination address, in user space.
230 * @from: Source address, in kernel space.
231 * @n: Number of bytes to copy.
233 * Context: User context only. This function may sleep.
235 * Copy data from kernel space to user space.
237 * Returns number of bytes that could not be copied.
238 * On success, this will be zero.
240 static inline unsigned long
241 copy_to_user(void __user
*to
, const void *from
, unsigned long n
)
244 if (access_ok(VERIFY_WRITE
, to
, n
))
245 n
= __copy_to_user(to
, from
, n
);
250 * __copy_from_user: - Copy a block of data from user space, with less checking.
251 * @to: Destination address, in kernel space.
252 * @from: Source address, in user space.
253 * @n: Number of bytes to copy.
255 * Context: User context only. This function may sleep.
257 * Copy data from user space to kernel space. Caller must check
258 * the specified block with access_ok() before calling this function.
260 * Returns number of bytes that could not be copied.
261 * On success, this will be zero.
263 * If some data could not be copied, this function will pad the copied
264 * data to the requested size using zero bytes.
266 static inline unsigned long
267 __copy_from_user(void *to
, const void __user
*from
, unsigned long n
)
269 if (__builtin_constant_p(n
) && (n
<= 256))
270 return uaccess
.copy_from_user_small(n
, from
, to
);
272 return uaccess
.copy_from_user(n
, from
, to
);
276 * copy_from_user: - Copy a block of data from user space.
277 * @to: Destination address, in kernel space.
278 * @from: Source address, in user space.
279 * @n: Number of bytes to copy.
281 * Context: User context only. This function may sleep.
283 * Copy data from user space to kernel space.
285 * Returns number of bytes that could not be copied.
286 * On success, this will be zero.
288 * If some data could not be copied, this function will pad the copied
289 * data to the requested size using zero bytes.
291 static inline unsigned long
292 copy_from_user(void *to
, const void __user
*from
, unsigned long n
)
295 if (access_ok(VERIFY_READ
, from
, n
))
296 n
= __copy_from_user(to
, from
, n
);
302 static inline unsigned long
303 __copy_in_user(void __user
*to
, const void __user
*from
, unsigned long n
)
305 return uaccess
.copy_in_user(n
, to
, from
);
308 static inline unsigned long
309 copy_in_user(void __user
*to
, const void __user
*from
, unsigned long n
)
312 if (__access_ok(from
,n
) && __access_ok(to
,n
))
313 n
= __copy_in_user(to
, from
, n
);
318 * Copy a null terminated string from userspace.
321 strncpy_from_user(char *dst
, const char __user
*src
, long count
)
325 if (access_ok(VERIFY_READ
, src
, 1))
326 res
= uaccess
.strncpy_from_user(count
, src
, dst
);
330 static inline unsigned long
331 strnlen_user(const char __user
* src
, unsigned long n
)
334 return uaccess
.strnlen_user(n
, src
);
338 * strlen_user: - Get the size of a string in user space.
339 * @str: The string to measure.
341 * Context: User context only. This function may sleep.
343 * Get the size of a NUL-terminated string in user space.
345 * Returns the size of the string INCLUDING the terminating NUL.
346 * On exception, returns 0.
348 * If there is a limit on the length of a valid string, you may wish to
349 * consider using strnlen_user() instead.
351 #define strlen_user(str) strnlen_user(str, ~0UL)
357 static inline unsigned long
358 __clear_user(void __user
*to
, unsigned long n
)
360 return uaccess
.clear_user(n
, to
);
363 static inline unsigned long
364 clear_user(void __user
*to
, unsigned long n
)
367 if (access_ok(VERIFY_WRITE
, to
, n
))
368 n
= uaccess
.clear_user(n
, to
);
372 #endif /* __S390_UACCESS_H */