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11#ifndef __S390_UACCESS_H
12#define __S390_UACCESS_H
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17#include <linux/sched.h>
18#include <linux/errno.h>
19
20#define VERIFY_READ 0
21#define VERIFY_WRITE 1
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31
32#define MAKE_MM_SEG(a) ((mm_segment_t) { (a) })
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35#define KERNEL_DS MAKE_MM_SEG(0)
36#define USER_DS MAKE_MM_SEG(1)
37
38#define get_ds() (KERNEL_DS)
39#define get_fs() (current->thread.mm_segment)
40
41#define set_fs(x) \
42({ \
43 unsigned long __pto; \
44 current->thread.mm_segment = (x); \
45 __pto = current->thread.mm_segment.ar4 ? \
46 S390_lowcore.user_asce : S390_lowcore.kernel_asce; \
47 __ctl_load(__pto, 7, 7); \
48})
49
50#define segment_eq(a,b) ((a).ar4 == (b).ar4)
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52
53static inline int __access_ok(const void __user *addr, unsigned long size)
54{
55 return 1;
56}
57#define access_ok(type,addr,size) __access_ok(addr,size)
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71
72struct exception_table_entry
73{
74 unsigned long insn, fixup;
75};
76
77struct uaccess_ops {
78 size_t (*copy_from_user)(size_t, const void __user *, void *);
79 size_t (*copy_from_user_small)(size_t, const void __user *, void *);
80 size_t (*copy_to_user)(size_t, void __user *, const void *);
81 size_t (*copy_to_user_small)(size_t, void __user *, const void *);
82 size_t (*copy_in_user)(size_t, void __user *, const void __user *);
83 size_t (*clear_user)(size_t, void __user *);
84 size_t (*strnlen_user)(size_t, const char __user *);
85 size_t (*strncpy_from_user)(size_t, const char __user *, char *);
86 int (*futex_atomic_op)(int op, int __user *, int oparg, int *old);
87 int (*futex_atomic_cmpxchg)(int __user *, int old, int new);
88};
89
90extern struct uaccess_ops uaccess;
91extern struct uaccess_ops uaccess_std;
92extern struct uaccess_ops uaccess_mvcos;
93extern struct uaccess_ops uaccess_mvcos_switch;
94extern struct uaccess_ops uaccess_pt;
95
96static inline int __put_user_fn(size_t size, void __user *ptr, void *x)
97{
98 size = uaccess.copy_to_user_small(size, ptr, x);
99 return size ? -EFAULT : size;
100}
101
102static inline int __get_user_fn(size_t size, const void __user *ptr, void *x)
103{
104 size = uaccess.copy_from_user_small(size, ptr, x);
105 return size ? -EFAULT : size;
106}
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111
112#define __put_user(x, ptr) \
113({ \
114 __typeof__(*(ptr)) __x = (x); \
115 int __pu_err = -EFAULT; \
116 __chk_user_ptr(ptr); \
117 switch (sizeof (*(ptr))) { \
118 case 1: \
119 case 2: \
120 case 4: \
121 case 8: \
122 __pu_err = __put_user_fn(sizeof (*(ptr)), \
123 ptr, &__x); \
124 break; \
125 default: \
126 __put_user_bad(); \
127 break; \
128 } \
129 __pu_err; \
130})
131
132#define put_user(x, ptr) \
133({ \
134 might_fault(); \
135 __put_user(x, ptr); \
136})
137
138
139extern int __put_user_bad(void) __attribute__((noreturn));
140
141#define __get_user(x, ptr) \
142({ \
143 int __gu_err = -EFAULT; \
144 __chk_user_ptr(ptr); \
145 switch (sizeof(*(ptr))) { \
146 case 1: { \
147 unsigned char __x; \
148 __gu_err = __get_user_fn(sizeof (*(ptr)), \
149 ptr, &__x); \
150 (x) = *(__force __typeof__(*(ptr)) *) &__x; \
151 break; \
152 }; \
153 case 2: { \
154 unsigned short __x; \
155 __gu_err = __get_user_fn(sizeof (*(ptr)), \
156 ptr, &__x); \
157 (x) = *(__force __typeof__(*(ptr)) *) &__x; \
158 break; \
159 }; \
160 case 4: { \
161 unsigned int __x; \
162 __gu_err = __get_user_fn(sizeof (*(ptr)), \
163 ptr, &__x); \
164 (x) = *(__force __typeof__(*(ptr)) *) &__x; \
165 break; \
166 }; \
167 case 8: { \
168 unsigned long long __x; \
169 __gu_err = __get_user_fn(sizeof (*(ptr)), \
170 ptr, &__x); \
171 (x) = *(__force __typeof__(*(ptr)) *) &__x; \
172 break; \
173 }; \
174 default: \
175 __get_user_bad(); \
176 break; \
177 } \
178 __gu_err; \
179})
180
181#define get_user(x, ptr) \
182({ \
183 might_fault(); \
184 __get_user(x, ptr); \
185})
186
187extern int __get_user_bad(void) __attribute__((noreturn));
188
189#define __put_user_unaligned __put_user
190#define __get_user_unaligned __get_user
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206static inline unsigned long __must_check
207__copy_to_user(void __user *to, const void *from, unsigned long n)
208{
209 if (__builtin_constant_p(n) && (n <= 256))
210 return uaccess.copy_to_user_small(n, to, from);
211 else
212 return uaccess.copy_to_user(n, to, from);
213}
214
215#define __copy_to_user_inatomic __copy_to_user
216#define __copy_from_user_inatomic __copy_from_user
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231static inline unsigned long __must_check
232copy_to_user(void __user *to, const void *from, unsigned long n)
233{
234 might_fault();
235 if (access_ok(VERIFY_WRITE, to, n))
236 n = __copy_to_user(to, from, n);
237 return n;
238}
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257static inline unsigned long __must_check
258__copy_from_user(void *to, const void __user *from, unsigned long n)
259{
260 if (__builtin_constant_p(n) && (n <= 256))
261 return uaccess.copy_from_user_small(n, from, to);
262 else
263 return uaccess.copy_from_user(n, from, to);
264}
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282static inline unsigned long __must_check
283copy_from_user(void *to, const void __user *from, unsigned long n)
284{
285 might_fault();
286 if (access_ok(VERIFY_READ, from, n))
287 n = __copy_from_user(to, from, n);
288 else
289 memset(to, 0, n);
290 return n;
291}
292
293static inline unsigned long __must_check
294__copy_in_user(void __user *to, const void __user *from, unsigned long n)
295{
296 return uaccess.copy_in_user(n, to, from);
297}
298
299static inline unsigned long __must_check
300copy_in_user(void __user *to, const void __user *from, unsigned long n)
301{
302 might_fault();
303 if (__access_ok(from,n) && __access_ok(to,n))
304 n = __copy_in_user(to, from, n);
305 return n;
306}
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311static inline long __must_check
312strncpy_from_user(char *dst, const char __user *src, long count)
313{
314 long res = -EFAULT;
315 might_fault();
316 if (access_ok(VERIFY_READ, src, 1))
317 res = uaccess.strncpy_from_user(count, src, dst);
318 return res;
319}
320
321static inline unsigned long
322strnlen_user(const char __user * src, unsigned long n)
323{
324 might_fault();
325 return uaccess.strnlen_user(n, src);
326}
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342#define strlen_user(str) strnlen_user(str, ~0UL)
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348static inline unsigned long __must_check
349__clear_user(void __user *to, unsigned long n)
350{
351 return uaccess.clear_user(n, to);
352}
353
354static inline unsigned long __must_check
355clear_user(void __user *to, unsigned long n)
356{
357 might_fault();
358 if (access_ok(VERIFY_WRITE, to, n))
359 n = uaccess.clear_user(n, to);
360 return n;
361}
362
363#endif
364