xref: /openbmc/linux/arch/parisc/include/asm/uaccess.h (revision 8fdff1dc)
1 #ifndef __PARISC_UACCESS_H
2 #define __PARISC_UACCESS_H
3 
4 /*
5  * User space memory access functions
6  */
7 #include <asm/page.h>
8 #include <asm/cache.h>
9 #include <asm/errno.h>
10 #include <asm-generic/uaccess-unaligned.h>
11 
12 #define VERIFY_READ 0
13 #define VERIFY_WRITE 1
14 
15 #define KERNEL_DS	((mm_segment_t){0})
16 #define USER_DS 	((mm_segment_t){1})
17 
18 #define segment_eq(a,b)	((a).seg == (b).seg)
19 
20 #define get_ds()	(KERNEL_DS)
21 #define get_fs()	(current_thread_info()->addr_limit)
22 #define set_fs(x)	(current_thread_info()->addr_limit = (x))
23 
24 /*
25  * Note that since kernel addresses are in a separate address space on
26  * parisc, we don't need to do anything for access_ok().
27  * We just let the page fault handler do the right thing. This also means
28  * that put_user is the same as __put_user, etc.
29  */
30 
31 extern int __get_kernel_bad(void);
32 extern int __get_user_bad(void);
33 extern int __put_kernel_bad(void);
34 extern int __put_user_bad(void);
35 
36 static inline long access_ok(int type, const void __user * addr,
37 		unsigned long size)
38 {
39 	return 1;
40 }
41 
42 #define put_user __put_user
43 #define get_user __get_user
44 
45 #if !defined(CONFIG_64BIT)
46 #define LDD_KERNEL(ptr)		__get_kernel_bad();
47 #define LDD_USER(ptr)		__get_user_bad();
48 #define STD_KERNEL(x, ptr)	__put_kernel_asm64(x,ptr)
49 #define STD_USER(x, ptr)	__put_user_asm64(x,ptr)
50 #define ASM_WORD_INSN		".word\t"
51 #else
52 #define LDD_KERNEL(ptr)		__get_kernel_asm("ldd",ptr)
53 #define LDD_USER(ptr)		__get_user_asm("ldd",ptr)
54 #define STD_KERNEL(x, ptr)	__put_kernel_asm("std",x,ptr)
55 #define STD_USER(x, ptr)	__put_user_asm("std",x,ptr)
56 #define ASM_WORD_INSN		".dword\t"
57 #endif
58 
59 /*
60  * The exception table contains two values: the first is an address
61  * for an instruction that is allowed to fault, and the second is
62  * the address to the fixup routine.
63  */
64 
65 struct exception_table_entry {
66 	unsigned long insn;  /* address of insn that is allowed to fault.   */
67 	long fixup;          /* fixup routine */
68 };
69 
70 #define ASM_EXCEPTIONTABLE_ENTRY( fault_addr, except_addr )\
71 	".section __ex_table,\"aw\"\n"			   \
72 	ASM_WORD_INSN #fault_addr ", " #except_addr "\n\t" \
73 	".previous\n"
74 
75 /*
76  * The page fault handler stores, in a per-cpu area, the following information
77  * if a fixup routine is available.
78  */
79 struct exception_data {
80 	unsigned long fault_ip;
81 	unsigned long fault_space;
82 	unsigned long fault_addr;
83 };
84 
85 #define __get_user(x,ptr)                               \
86 ({                                                      \
87 	register long __gu_err __asm__ ("r8") = 0;      \
88 	register long __gu_val __asm__ ("r9") = 0;      \
89 							\
90 	if (segment_eq(get_fs(),KERNEL_DS)) {           \
91 	    switch (sizeof(*(ptr))) {                   \
92 	    case 1: __get_kernel_asm("ldb",ptr); break; \
93 	    case 2: __get_kernel_asm("ldh",ptr); break; \
94 	    case 4: __get_kernel_asm("ldw",ptr); break; \
95 	    case 8: LDD_KERNEL(ptr); break;		\
96 	    default: __get_kernel_bad(); break;         \
97 	    }                                           \
98 	}                                               \
99 	else {                                          \
100 	    switch (sizeof(*(ptr))) {                   \
101 	    case 1: __get_user_asm("ldb",ptr); break;   \
102 	    case 2: __get_user_asm("ldh",ptr); break;   \
103 	    case 4: __get_user_asm("ldw",ptr); break;   \
104 	    case 8: LDD_USER(ptr);  break;		\
105 	    default: __get_user_bad(); break;           \
106 	    }                                           \
107 	}                                               \
108 							\
109 	(x) = (__typeof__(*(ptr))) __gu_val;            \
110 	__gu_err;                                       \
111 })
112 
113 #define __get_kernel_asm(ldx,ptr)                       \
114 	__asm__("\n1:\t" ldx "\t0(%2),%0\n\t"		\
115 		ASM_EXCEPTIONTABLE_ENTRY(1b, fixup_get_user_skip_1)\
116 		: "=r"(__gu_val), "=r"(__gu_err)        \
117 		: "r"(ptr), "1"(__gu_err)		\
118 		: "r1");
119 
120 #define __get_user_asm(ldx,ptr)                         \
121 	__asm__("\n1:\t" ldx "\t0(%%sr3,%2),%0\n\t"	\
122 		ASM_EXCEPTIONTABLE_ENTRY(1b,fixup_get_user_skip_1)\
123 		: "=r"(__gu_val), "=r"(__gu_err)        \
124 		: "r"(ptr), "1"(__gu_err)		\
125 		: "r1");
126 
127 #define __put_user(x,ptr)                                       \
128 ({								\
129 	register long __pu_err __asm__ ("r8") = 0;      	\
130         __typeof__(*(ptr)) __x = (__typeof__(*(ptr)))(x);	\
131 								\
132 	if (segment_eq(get_fs(),KERNEL_DS)) {                   \
133 	    switch (sizeof(*(ptr))) {                           \
134 	    case 1: __put_kernel_asm("stb",__x,ptr); break;     \
135 	    case 2: __put_kernel_asm("sth",__x,ptr); break;     \
136 	    case 4: __put_kernel_asm("stw",__x,ptr); break;     \
137 	    case 8: STD_KERNEL(__x,ptr); break;			\
138 	    default: __put_kernel_bad(); break;			\
139 	    }                                                   \
140 	}                                                       \
141 	else {                                                  \
142 	    switch (sizeof(*(ptr))) {                           \
143 	    case 1: __put_user_asm("stb",__x,ptr); break;       \
144 	    case 2: __put_user_asm("sth",__x,ptr); break;       \
145 	    case 4: __put_user_asm("stw",__x,ptr); break;       \
146 	    case 8: STD_USER(__x,ptr); break;			\
147 	    default: __put_user_bad(); break;			\
148 	    }                                                   \
149 	}                                                       \
150 								\
151 	__pu_err;						\
152 })
153 
154 /*
155  * The "__put_user/kernel_asm()" macros tell gcc they read from memory
156  * instead of writing. This is because they do not write to any memory
157  * gcc knows about, so there are no aliasing issues. These macros must
158  * also be aware that "fixup_put_user_skip_[12]" are executed in the
159  * context of the fault, and any registers used there must be listed
160  * as clobbers. In this case only "r1" is used by the current routines.
161  * r8/r9 are already listed as err/val.
162  */
163 
164 #define __put_kernel_asm(stx,x,ptr)                         \
165 	__asm__ __volatile__ (                              \
166 		"\n1:\t" stx "\t%2,0(%1)\n\t"		    \
167 		ASM_EXCEPTIONTABLE_ENTRY(1b,fixup_put_user_skip_1)\
168 		: "=r"(__pu_err)                            \
169 		: "r"(ptr), "r"(x), "0"(__pu_err)	    \
170 	    	: "r1")
171 
172 #define __put_user_asm(stx,x,ptr)                           \
173 	__asm__ __volatile__ (                              \
174 		"\n1:\t" stx "\t%2,0(%%sr3,%1)\n\t"	    \
175 		ASM_EXCEPTIONTABLE_ENTRY(1b,fixup_put_user_skip_1)\
176 		: "=r"(__pu_err)                            \
177 		: "r"(ptr), "r"(x), "0"(__pu_err)	    \
178 		: "r1")
179 
180 
181 #if !defined(CONFIG_64BIT)
182 
183 #define __put_kernel_asm64(__val,ptr) do {		    \
184 	u64 __val64 = (u64)(__val);			    \
185 	u32 hi = (__val64) >> 32;			    \
186 	u32 lo = (__val64) & 0xffffffff;		    \
187 	__asm__ __volatile__ (				    \
188 		"\n1:\tstw %2,0(%1)"			    \
189 		"\n2:\tstw %3,4(%1)\n\t"		    \
190 		ASM_EXCEPTIONTABLE_ENTRY(1b,fixup_put_user_skip_2)\
191 		ASM_EXCEPTIONTABLE_ENTRY(2b,fixup_put_user_skip_1)\
192 		: "=r"(__pu_err)                            \
193 		: "r"(ptr), "r"(hi), "r"(lo), "0"(__pu_err) \
194 		: "r1");				    \
195 } while (0)
196 
197 #define __put_user_asm64(__val,ptr) do {	    	    \
198 	u64 __val64 = (u64)(__val);			    \
199 	u32 hi = (__val64) >> 32;			    \
200 	u32 lo = (__val64) & 0xffffffff;		    \
201 	__asm__ __volatile__ (				    \
202 		"\n1:\tstw %2,0(%%sr3,%1)"		    \
203 		"\n2:\tstw %3,4(%%sr3,%1)\n\t"		    \
204 		ASM_EXCEPTIONTABLE_ENTRY(1b,fixup_put_user_skip_2)\
205 		ASM_EXCEPTIONTABLE_ENTRY(2b,fixup_put_user_skip_1)\
206 		: "=r"(__pu_err)                            \
207 		: "r"(ptr), "r"(hi), "r"(lo), "0"(__pu_err) \
208 		: "r1");				    \
209 } while (0)
210 
211 #endif /* !defined(CONFIG_64BIT) */
212 
213 
214 /*
215  * Complex access routines -- external declarations
216  */
217 
218 extern unsigned long lcopy_to_user(void __user *, const void *, unsigned long);
219 extern unsigned long lcopy_from_user(void *, const void __user *, unsigned long);
220 extern unsigned long lcopy_in_user(void __user *, const void __user *, unsigned long);
221 extern long strncpy_from_user(char *, const char __user *, long);
222 extern unsigned lclear_user(void __user *,unsigned long);
223 extern long lstrnlen_user(const char __user *,long);
224 /*
225  * Complex access routines -- macros
226  */
227 #define user_addr_max() (~0UL)
228 
229 #define strnlen_user lstrnlen_user
230 #define strlen_user(str) lstrnlen_user(str, 0x7fffffffL)
231 #define clear_user lclear_user
232 #define __clear_user lclear_user
233 
234 unsigned long copy_to_user(void __user *dst, const void *src, unsigned long len);
235 #define __copy_to_user copy_to_user
236 unsigned long __copy_from_user(void *dst, const void __user *src, unsigned long len);
237 unsigned long copy_in_user(void __user *dst, const void __user *src, unsigned long len);
238 #define __copy_in_user copy_in_user
239 #define __copy_to_user_inatomic __copy_to_user
240 #define __copy_from_user_inatomic __copy_from_user
241 
242 extern void copy_from_user_overflow(void)
243 #ifdef CONFIG_DEBUG_STRICT_USER_COPY_CHECKS
244         __compiletime_error("copy_from_user() buffer size is not provably correct")
245 #else
246         __compiletime_warning("copy_from_user() buffer size is not provably correct")
247 #endif
248 ;
249 
250 static inline unsigned long __must_check copy_from_user(void *to,
251                                           const void __user *from,
252                                           unsigned long n)
253 {
254         int sz = __compiletime_object_size(to);
255         int ret = -EFAULT;
256 
257         if (likely(sz == -1 || !__builtin_constant_p(n) || sz >= n))
258                 ret = __copy_from_user(to, from, n);
259         else
260                 copy_from_user_overflow();
261 
262         return ret;
263 }
264 
265 struct pt_regs;
266 int fixup_exception(struct pt_regs *regs);
267 
268 #endif /* __PARISC_UACCESS_H */
269