1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_UACCESS_H
3 #define _ASM_UACCESS_H
4
5 /*
6 * User space memory access functions
7 */
8
9 #include <linux/compiler.h>
10 #include <linux/string.h>
11 #include <asm/asi.h>
12 #include <asm/spitfire.h>
13
14 #include <asm/processor.h>
15
16 /*
17 * Sparc64 is segmented, though more like the M68K than the I386.
18 * We use the secondary ASI to address user memory, which references a
19 * completely different VM map, thus there is zero chance of the user
20 * doing something queer and tricking us into poking kernel memory.
21 *
22 * What is left here is basically what is needed for the other parts of
23 * the kernel that expect to be able to manipulate, erum, "segments".
24 * Or perhaps more properly, permissions.
25 *
26 * "For historical reasons, these macros are grossly misnamed." -Linus
27 */
28
29 #define KERNEL_DS ((mm_segment_t) { ASI_P })
30 #define USER_DS ((mm_segment_t) { ASI_AIUS }) /* har har har */
31
32 #define get_fs() ((mm_segment_t){(current_thread_info()->current_ds)})
33
34 #define uaccess_kernel() (get_fs().seg == KERNEL_DS.seg)
35
36 #define set_fs(val) \
37 do { \
38 current_thread_info()->current_ds = (val).seg; \
39 __asm__ __volatile__ ("wr %%g0, %0, %%asi" : : "r" ((val).seg)); \
40 } while(0)
41
42 /*
43 * Test whether a block of memory is a valid user space address.
44 * Returns 0 if the range is valid, nonzero otherwise.
45 */
__chk_range_not_ok(unsigned long addr,unsigned long size,unsigned long limit)46 static inline bool __chk_range_not_ok(unsigned long addr, unsigned long size, unsigned long limit)
47 {
48 if (__builtin_constant_p(size))
49 return addr > limit - size;
50
51 addr += size;
52 if (addr < size)
53 return true;
54
55 return addr > limit;
56 }
57
58 #define __range_not_ok(addr, size, limit) \
59 ({ \
60 __chk_user_ptr(addr); \
61 __chk_range_not_ok((unsigned long __force)(addr), size, limit); \
62 })
63
__access_ok(const void __user * addr,unsigned long size)64 static inline int __access_ok(const void __user * addr, unsigned long size)
65 {
66 return 1;
67 }
68
access_ok(const void __user * addr,unsigned long size)69 static inline int access_ok(const void __user * addr, unsigned long size)
70 {
71 return 1;
72 }
73
74 void __retl_efault(void);
75
76 /* Uh, these should become the main single-value transfer routines..
77 * They automatically use the right size if we just have the right
78 * pointer type..
79 *
80 * This gets kind of ugly. We want to return _two_ values in "get_user()"
81 * and yet we don't want to do any pointers, because that is too much
82 * of a performance impact. Thus we have a few rather ugly macros here,
83 * and hide all the ugliness from the user.
84 */
85 #define put_user(x, ptr) ({ \
86 unsigned long __pu_addr = (unsigned long)(ptr); \
87 __chk_user_ptr(ptr); \
88 __put_user_nocheck((__typeof__(*(ptr)))(x), __pu_addr, sizeof(*(ptr)));\
89 })
90
91 #define get_user(x, ptr) ({ \
92 unsigned long __gu_addr = (unsigned long)(ptr); \
93 __chk_user_ptr(ptr); \
94 __get_user_nocheck((x), __gu_addr, sizeof(*(ptr)), __typeof__(*(ptr)));\
95 })
96
97 #define __put_user(x, ptr) put_user(x, ptr)
98 #define __get_user(x, ptr) get_user(x, ptr)
99
100 struct __large_struct { unsigned long buf[100]; };
101 #define __m(x) ((struct __large_struct *)(x))
102
103 #define __put_user_nocheck(data, addr, size) ({ \
104 register int __pu_ret; \
105 switch (size) { \
106 case 1: __put_user_asm(data, b, addr, __pu_ret); break; \
107 case 2: __put_user_asm(data, h, addr, __pu_ret); break; \
108 case 4: __put_user_asm(data, w, addr, __pu_ret); break; \
109 case 8: __put_user_asm(data, x, addr, __pu_ret); break; \
110 default: __pu_ret = __put_user_bad(); break; \
111 } \
112 __pu_ret; \
113 })
114
115 #define __put_user_asm(x, size, addr, ret) \
116 __asm__ __volatile__( \
117 "/* Put user asm, inline. */\n" \
118 "1:\t" "st"#size "a %1, [%2] %%asi\n\t" \
119 "clr %0\n" \
120 "2:\n\n\t" \
121 ".section .fixup,#alloc,#execinstr\n\t" \
122 ".align 4\n" \
123 "3:\n\t" \
124 "sethi %%hi(2b), %0\n\t" \
125 "jmpl %0 + %%lo(2b), %%g0\n\t" \
126 " mov %3, %0\n\n\t" \
127 ".previous\n\t" \
128 ".section __ex_table,\"a\"\n\t" \
129 ".align 4\n\t" \
130 ".word 1b, 3b\n\t" \
131 ".previous\n\n\t" \
132 : "=r" (ret) : "r" (x), "r" (__m(addr)), \
133 "i" (-EFAULT))
134
135 int __put_user_bad(void);
136
137 #define __get_user_nocheck(data, addr, size, type) ({ \
138 register int __gu_ret; \
139 register unsigned long __gu_val; \
140 switch (size) { \
141 case 1: __get_user_asm(__gu_val, ub, addr, __gu_ret); break; \
142 case 2: __get_user_asm(__gu_val, uh, addr, __gu_ret); break; \
143 case 4: __get_user_asm(__gu_val, uw, addr, __gu_ret); break; \
144 case 8: __get_user_asm(__gu_val, x, addr, __gu_ret); break; \
145 default: \
146 __gu_val = 0; \
147 __gu_ret = __get_user_bad(); \
148 break; \
149 } \
150 data = (__force type) __gu_val; \
151 __gu_ret; \
152 })
153
154 #define __get_user_asm(x, size, addr, ret) \
155 __asm__ __volatile__( \
156 "/* Get user asm, inline. */\n" \
157 "1:\t" "ld"#size "a [%2] %%asi, %1\n\t" \
158 "clr %0\n" \
159 "2:\n\n\t" \
160 ".section .fixup,#alloc,#execinstr\n\t" \
161 ".align 4\n" \
162 "3:\n\t" \
163 "sethi %%hi(2b), %0\n\t" \
164 "clr %1\n\t" \
165 "jmpl %0 + %%lo(2b), %%g0\n\t" \
166 " mov %3, %0\n\n\t" \
167 ".previous\n\t" \
168 ".section __ex_table,\"a\"\n\t" \
169 ".align 4\n\t" \
170 ".word 1b, 3b\n\n\t" \
171 ".previous\n\t" \
172 : "=r" (ret), "=r" (x) : "r" (__m(addr)), \
173 "i" (-EFAULT))
174
175 int __get_user_bad(void);
176
177 unsigned long __must_check raw_copy_from_user(void *to,
178 const void __user *from,
179 unsigned long size);
180
181 unsigned long __must_check raw_copy_to_user(void __user *to,
182 const void *from,
183 unsigned long size);
184 #define INLINE_COPY_FROM_USER
185 #define INLINE_COPY_TO_USER
186
187 unsigned long __must_check raw_copy_in_user(void __user *to,
188 const void __user *from,
189 unsigned long size);
190
191 unsigned long __must_check __clear_user(void __user *, unsigned long);
192
193 #define clear_user __clear_user
194
195 __must_check long strnlen_user(const char __user *str, long n);
196
197 struct pt_regs;
198 unsigned long compute_effective_address(struct pt_regs *,
199 unsigned int insn,
200 unsigned int rd);
201
202 #endif /* _ASM_UACCESS_H */
203