1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __ALPHA_UACCESS_H
3 #define __ALPHA_UACCESS_H
4 
5 #include <asm-generic/access_ok.h>
6 /*
7  * These are the main single-value transfer routines.  They automatically
8  * use the right size if we just have the right pointer type.
9  *
10  * As the alpha uses the same address space for kernel and user
11  * data, we can just do these as direct assignments.  (Of course, the
12  * exception handling means that it's no longer "just"...)
13  *
14  * Careful to not
15  * (a) re-use the arguments for side effects (sizeof/typeof is ok)
16  * (b) require any knowledge of processes at this stage
17  */
18 #define put_user(x, ptr) \
19   __put_user_check((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
20 #define get_user(x, ptr) \
21   __get_user_check((x), (ptr), sizeof(*(ptr)))
22 
23 /*
24  * The "__xxx" versions do not do address space checking, useful when
25  * doing multiple accesses to the same area (the programmer has to do the
26  * checks by hand with "access_ok()")
27  */
28 #define __put_user(x, ptr) \
29   __put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
30 #define __get_user(x, ptr) \
31   __get_user_nocheck((x), (ptr), sizeof(*(ptr)))
32 
33 /*
34  * The "lda %1, 2b-1b(%0)" bits are magic to get the assembler to
35  * encode the bits we need for resolving the exception.  See the
36  * more extensive comments with fixup_inline_exception below for
37  * more information.
38  */
39 #define EXC(label,cont,res,err)				\
40 	".section __ex_table,\"a\"\n"			\
41 	"	.long "#label"-.\n"			\
42 	"	lda "#res","#cont"-"#label"("#err")\n"	\
43 	".previous\n"
44 
45 extern void __get_user_unknown(void);
46 
47 #define __get_user_nocheck(x, ptr, size)			\
48 ({								\
49 	long __gu_err = 0;					\
50 	unsigned long __gu_val;					\
51 	__chk_user_ptr(ptr);					\
52 	switch (size) {						\
53 	  case 1: __get_user_8(ptr); break;			\
54 	  case 2: __get_user_16(ptr); break;			\
55 	  case 4: __get_user_32(ptr); break;			\
56 	  case 8: __get_user_64(ptr); break;			\
57 	  default: __get_user_unknown(); break;			\
58 	}							\
59 	(x) = (__force __typeof__(*(ptr))) __gu_val;		\
60 	__gu_err;						\
61 })
62 
63 #define __get_user_check(x, ptr, size)				\
64 ({								\
65 	long __gu_err = -EFAULT;				\
66 	unsigned long __gu_val = 0;				\
67 	const __typeof__(*(ptr)) __user *__gu_addr = (ptr);	\
68 	if (__access_ok(__gu_addr, size)) {			\
69 		__gu_err = 0;					\
70 		switch (size) {					\
71 		  case 1: __get_user_8(__gu_addr); break;	\
72 		  case 2: __get_user_16(__gu_addr); break;	\
73 		  case 4: __get_user_32(__gu_addr); break;	\
74 		  case 8: __get_user_64(__gu_addr); break;	\
75 		  default: __get_user_unknown(); break;		\
76 		}						\
77 	}							\
78 	(x) = (__force __typeof__(*(ptr))) __gu_val;		\
79 	__gu_err;						\
80 })
81 
82 struct __large_struct { unsigned long buf[100]; };
83 #define __m(x) (*(struct __large_struct __user *)(x))
84 
85 #define __get_user_64(addr)				\
86 	__asm__("1: ldq %0,%2\n"			\
87 	"2:\n"						\
88 	EXC(1b,2b,%0,%1)				\
89 		: "=r"(__gu_val), "=r"(__gu_err)	\
90 		: "m"(__m(addr)), "1"(__gu_err))
91 
92 #define __get_user_32(addr)				\
93 	__asm__("1: ldl %0,%2\n"			\
94 	"2:\n"						\
95 	EXC(1b,2b,%0,%1)				\
96 		: "=r"(__gu_val), "=r"(__gu_err)	\
97 		: "m"(__m(addr)), "1"(__gu_err))
98 
99 #ifdef __alpha_bwx__
100 /* Those lucky bastards with ev56 and later CPUs can do byte/word moves.  */
101 
102 #define __get_user_16(addr)				\
103 	__asm__("1: ldwu %0,%2\n"			\
104 	"2:\n"						\
105 	EXC(1b,2b,%0,%1)				\
106 		: "=r"(__gu_val), "=r"(__gu_err)	\
107 		: "m"(__m(addr)), "1"(__gu_err))
108 
109 #define __get_user_8(addr)				\
110 	__asm__("1: ldbu %0,%2\n"			\
111 	"2:\n"						\
112 	EXC(1b,2b,%0,%1)				\
113 		: "=r"(__gu_val), "=r"(__gu_err)	\
114 		: "m"(__m(addr)), "1"(__gu_err))
115 #else
116 /* Unfortunately, we can't get an unaligned access trap for the sub-word
117    load, so we have to do a general unaligned operation.  */
118 
119 #define __get_user_16(addr)						\
120 {									\
121 	long __gu_tmp;							\
122 	__asm__("1: ldq_u %0,0(%3)\n"					\
123 	"2:	ldq_u %1,1(%3)\n"					\
124 	"	extwl %0,%3,%0\n"					\
125 	"	extwh %1,%3,%1\n"					\
126 	"	or %0,%1,%0\n"						\
127 	"3:\n"								\
128 	EXC(1b,3b,%0,%2)						\
129 	EXC(2b,3b,%0,%2)						\
130 		: "=&r"(__gu_val), "=&r"(__gu_tmp), "=r"(__gu_err)	\
131 		: "r"(addr), "2"(__gu_err));				\
132 }
133 
134 #define __get_user_8(addr)						\
135 	__asm__("1: ldq_u %0,0(%2)\n"					\
136 	"	extbl %0,%2,%0\n"					\
137 	"2:\n"								\
138 	EXC(1b,2b,%0,%1)						\
139 		: "=&r"(__gu_val), "=r"(__gu_err)			\
140 		: "r"(addr), "1"(__gu_err))
141 #endif
142 
143 extern void __put_user_unknown(void);
144 
145 #define __put_user_nocheck(x, ptr, size)			\
146 ({								\
147 	long __pu_err = 0;					\
148 	__chk_user_ptr(ptr);					\
149 	switch (size) {						\
150 	  case 1: __put_user_8(x, ptr); break;			\
151 	  case 2: __put_user_16(x, ptr); break;			\
152 	  case 4: __put_user_32(x, ptr); break;			\
153 	  case 8: __put_user_64(x, ptr); break;			\
154 	  default: __put_user_unknown(); break;			\
155 	}							\
156 	__pu_err;						\
157 })
158 
159 #define __put_user_check(x, ptr, size)				\
160 ({								\
161 	long __pu_err = -EFAULT;				\
162 	__typeof__(*(ptr)) __user *__pu_addr = (ptr);		\
163 	if (__access_ok(__pu_addr, size)) {			\
164 		__pu_err = 0;					\
165 		switch (size) {					\
166 		  case 1: __put_user_8(x, __pu_addr); break;	\
167 		  case 2: __put_user_16(x, __pu_addr); break;	\
168 		  case 4: __put_user_32(x, __pu_addr); break;	\
169 		  case 8: __put_user_64(x, __pu_addr); break;	\
170 		  default: __put_user_unknown(); break;		\
171 		}						\
172 	}							\
173 	__pu_err;						\
174 })
175 
176 /*
177  * The "__put_user_xx()" macros tell gcc they read from memory
178  * instead of writing: this is because they do not write to
179  * any memory gcc knows about, so there are no aliasing issues
180  */
181 #define __put_user_64(x, addr)					\
182 __asm__ __volatile__("1: stq %r2,%1\n"				\
183 	"2:\n"							\
184 	EXC(1b,2b,$31,%0)					\
185 		: "=r"(__pu_err)				\
186 		: "m" (__m(addr)), "rJ" (x), "0"(__pu_err))
187 
188 #define __put_user_32(x, addr)					\
189 __asm__ __volatile__("1: stl %r2,%1\n"				\
190 	"2:\n"							\
191 	EXC(1b,2b,$31,%0)					\
192 		: "=r"(__pu_err)				\
193 		: "m"(__m(addr)), "rJ"(x), "0"(__pu_err))
194 
195 #ifdef __alpha_bwx__
196 /* Those lucky bastards with ev56 and later CPUs can do byte/word moves.  */
197 
198 #define __put_user_16(x, addr)					\
199 __asm__ __volatile__("1: stw %r2,%1\n"				\
200 	"2:\n"							\
201 	EXC(1b,2b,$31,%0)					\
202 		: "=r"(__pu_err)				\
203 		: "m"(__m(addr)), "rJ"(x), "0"(__pu_err))
204 
205 #define __put_user_8(x, addr)					\
206 __asm__ __volatile__("1: stb %r2,%1\n"				\
207 	"2:\n"							\
208 	EXC(1b,2b,$31,%0)					\
209 		: "=r"(__pu_err)				\
210 		: "m"(__m(addr)), "rJ"(x), "0"(__pu_err))
211 #else
212 /* Unfortunately, we can't get an unaligned access trap for the sub-word
213    write, so we have to do a general unaligned operation.  */
214 
215 #define __put_user_16(x, addr)					\
216 {								\
217 	long __pu_tmp1, __pu_tmp2, __pu_tmp3, __pu_tmp4;	\
218 	__asm__ __volatile__(					\
219 	"1:	ldq_u %2,1(%5)\n"				\
220 	"2:	ldq_u %1,0(%5)\n"				\
221 	"	inswh %6,%5,%4\n"				\
222 	"	inswl %6,%5,%3\n"				\
223 	"	mskwh %2,%5,%2\n"				\
224 	"	mskwl %1,%5,%1\n"				\
225 	"	or %2,%4,%2\n"					\
226 	"	or %1,%3,%1\n"					\
227 	"3:	stq_u %2,1(%5)\n"				\
228 	"4:	stq_u %1,0(%5)\n"				\
229 	"5:\n"							\
230 	EXC(1b,5b,$31,%0)					\
231 	EXC(2b,5b,$31,%0)					\
232 	EXC(3b,5b,$31,%0)					\
233 	EXC(4b,5b,$31,%0)					\
234 		: "=r"(__pu_err), "=&r"(__pu_tmp1), 		\
235 		  "=&r"(__pu_tmp2), "=&r"(__pu_tmp3), 		\
236 		  "=&r"(__pu_tmp4)				\
237 		: "r"(addr), "r"((unsigned long)(x)), "0"(__pu_err)); \
238 }
239 
240 #define __put_user_8(x, addr)					\
241 {								\
242 	long __pu_tmp1, __pu_tmp2;				\
243 	__asm__ __volatile__(					\
244 	"1:	ldq_u %1,0(%4)\n"				\
245 	"	insbl %3,%4,%2\n"				\
246 	"	mskbl %1,%4,%1\n"				\
247 	"	or %1,%2,%1\n"					\
248 	"2:	stq_u %1,0(%4)\n"				\
249 	"3:\n"							\
250 	EXC(1b,3b,$31,%0)					\
251 	EXC(2b,3b,$31,%0)					\
252 		: "=r"(__pu_err), 				\
253 	  	  "=&r"(__pu_tmp1), "=&r"(__pu_tmp2)		\
254 		: "r"((unsigned long)(x)), "r"(addr), "0"(__pu_err)); \
255 }
256 #endif
257 
258 
259 /*
260  * Complex access routines
261  */
262 
263 extern long __copy_user(void *to, const void *from, long len);
264 
265 static inline unsigned long
raw_copy_from_user(void * to,const void __user * from,unsigned long len)266 raw_copy_from_user(void *to, const void __user *from, unsigned long len)
267 {
268 	return __copy_user(to, (__force const void *)from, len);
269 }
270 
271 static inline unsigned long
raw_copy_to_user(void __user * to,const void * from,unsigned long len)272 raw_copy_to_user(void __user *to, const void *from, unsigned long len)
273 {
274 	return __copy_user((__force void *)to, from, len);
275 }
276 
277 extern long __clear_user(void __user *to, long len);
278 
279 static inline long
clear_user(void __user * to,long len)280 clear_user(void __user *to, long len)
281 {
282 	if (__access_ok(to, len))
283 		len = __clear_user(to, len);
284 	return len;
285 }
286 
287 extern long strncpy_from_user(char *dest, const char __user *src, long count);
288 extern __must_check long strnlen_user(const char __user *str, long n);
289 
290 #include <asm/extable.h>
291 
292 #endif /* __ALPHA_UACCESS_H */
293