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 #include <linux/bug.h>
13 #include <linux/string.h>
14 #include <linux/thread_info.h>
15
16 #define VERIFY_READ 0
17 #define VERIFY_WRITE 1
18
19 #define KERNEL_DS ((mm_segment_t){0})
20 #define USER_DS ((mm_segment_t){1})
21
22 #define segment_eq(a, b) ((a).seg == (b).seg)
23
24 #define get_ds() (KERNEL_DS)
25 #define get_fs() (current_thread_info()->addr_limit)
26 #define set_fs(x) (current_thread_info()->addr_limit = (x))
27
28 /*
29 * Note that since kernel addresses are in a separate address space on
30 * parisc, we don't need to do anything for access_ok().
31 * We just let the page fault handler do the right thing. This also means
32 * that put_user is the same as __put_user, etc.
33 */
34
access_ok(int type,const void __user * addr,unsigned long size)35 static inline long access_ok(int type, const void __user * addr,
36 unsigned long size)
37 {
38 return 1;
39 }
40
41 #define put_user __put_user
42 #define get_user __get_user
43
44 #if !defined(CONFIG_64BIT)
45 #define LDD_USER(val, ptr) __get_user_asm64(val, ptr)
46 #define STD_USER(x, ptr) __put_user_asm64(x, ptr)
47 #else
48 #define LDD_USER(val, ptr) __get_user_asm(val, "ldd", ptr)
49 #define STD_USER(x, ptr) __put_user_asm("std", x, ptr)
50 #endif
51
52 /*
53 * The exception table contains two values: the first is the relative offset to
54 * the address of the instruction that is allowed to fault, and the second is
55 * the relative offset to the address of the fixup routine. Since relative
56 * addresses are used, 32bit values are sufficient even on 64bit kernel.
57 */
58
59 #define ARCH_HAS_RELATIVE_EXTABLE
60 struct exception_table_entry {
61 int insn; /* relative address of insn that is allowed to fault. */
62 int fixup; /* relative address of fixup routine */
63 };
64
65 #define ASM_EXCEPTIONTABLE_ENTRY( fault_addr, except_addr )\
66 ".section __ex_table,\"aw\"\n" \
67 ".word (" #fault_addr " - .), (" #except_addr " - .)\n\t" \
68 ".previous\n"
69
70 /*
71 * ASM_EXCEPTIONTABLE_ENTRY_EFAULT() creates a special exception table entry
72 * (with lowest bit set) for which the fault handler in fixup_exception() will
73 * load -EFAULT into %r8 for a read or write fault, and zeroes the target
74 * register in case of a read fault in get_user().
75 */
76 #define ASM_EXCEPTIONTABLE_ENTRY_EFAULT( fault_addr, except_addr )\
77 ASM_EXCEPTIONTABLE_ENTRY( fault_addr, except_addr + 1)
78
79 /*
80 * The page fault handler stores, in a per-cpu area, the following information
81 * if a fixup routine is available.
82 */
83 struct exception_data {
84 unsigned long fault_ip;
85 unsigned long fault_gp;
86 unsigned long fault_space;
87 unsigned long fault_addr;
88 };
89
90 /*
91 * load_sr2() preloads the space register %%sr2 - based on the value of
92 * get_fs() - with either a value of 0 to access kernel space (KERNEL_DS which
93 * is 0), or with the current value of %%sr3 to access user space (USER_DS)
94 * memory. The following __get_user_asm() and __put_user_asm() functions have
95 * %%sr2 hard-coded to access the requested memory.
96 */
97 #define load_sr2() \
98 __asm__(" or,= %0,%%r0,%%r0\n\t" \
99 " mfsp %%sr3,%0\n\t" \
100 " mtsp %0,%%sr2\n\t" \
101 : : "r"(get_fs()) : )
102
103 #define __get_user_internal(val, ptr) \
104 ({ \
105 register long __gu_err __asm__ ("r8") = 0; \
106 \
107 switch (sizeof(*(ptr))) { \
108 case 1: __get_user_asm(val, "ldb", ptr); break; \
109 case 2: __get_user_asm(val, "ldh", ptr); break; \
110 case 4: __get_user_asm(val, "ldw", ptr); break; \
111 case 8: LDD_USER(val, ptr); break; \
112 default: BUILD_BUG(); \
113 } \
114 \
115 __gu_err; \
116 })
117
118 #define __get_user(val, ptr) \
119 ({ \
120 load_sr2(); \
121 __get_user_internal(val, ptr); \
122 })
123
124 #define __get_user_asm(val, ldx, ptr) \
125 { \
126 register long __gu_val; \
127 \
128 __asm__("1: " ldx " 0(%%sr2,%2),%0\n" \
129 "9:\n" \
130 ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 9b) \
131 : "=r"(__gu_val), "=r"(__gu_err) \
132 : "r"(ptr), "1"(__gu_err)); \
133 \
134 (val) = (__force __typeof__(*(ptr))) __gu_val; \
135 }
136
137 #if !defined(CONFIG_64BIT)
138
139 #define __get_user_asm64(val, ptr) \
140 { \
141 union { \
142 unsigned long long l; \
143 __typeof__(*(ptr)) t; \
144 } __gu_tmp; \
145 \
146 __asm__(" copy %%r0,%R0\n" \
147 "1: ldw 0(%%sr2,%2),%0\n" \
148 "2: ldw 4(%%sr2,%2),%R0\n" \
149 "9:\n" \
150 ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 9b) \
151 ASM_EXCEPTIONTABLE_ENTRY_EFAULT(2b, 9b) \
152 : "=&r"(__gu_tmp.l), "=r"(__gu_err) \
153 : "r"(ptr), "1"(__gu_err)); \
154 \
155 (val) = __gu_tmp.t; \
156 }
157
158 #endif /* !defined(CONFIG_64BIT) */
159
160
161 #define __put_user_internal(x, ptr) \
162 ({ \
163 register long __pu_err __asm__ ("r8") = 0; \
164 __typeof__(*(ptr)) __x = (__typeof__(*(ptr)))(x); \
165 \
166 switch (sizeof(*(ptr))) { \
167 case 1: __put_user_asm("stb", __x, ptr); break; \
168 case 2: __put_user_asm("sth", __x, ptr); break; \
169 case 4: __put_user_asm("stw", __x, ptr); break; \
170 case 8: STD_USER(__x, ptr); break; \
171 default: BUILD_BUG(); \
172 } \
173 \
174 __pu_err; \
175 })
176
177 #define __put_user(x, ptr) \
178 ({ \
179 load_sr2(); \
180 __put_user_internal(x, ptr); \
181 })
182
183
184 /*
185 * The "__put_user/kernel_asm()" macros tell gcc they read from memory
186 * instead of writing. This is because they do not write to any memory
187 * gcc knows about, so there are no aliasing issues. These macros must
188 * also be aware that fixups are executed in the context of the fault,
189 * and any registers used there must be listed as clobbers.
190 * r8 is already listed as err.
191 */
192
193 #define __put_user_asm(stx, x, ptr) \
194 __asm__ __volatile__ ( \
195 "1: " stx " %2,0(%%sr2,%1)\n" \
196 "9:\n" \
197 ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 9b) \
198 : "=r"(__pu_err) \
199 : "r"(ptr), "r"(x), "0"(__pu_err))
200
201
202 #if !defined(CONFIG_64BIT)
203
204 #define __put_user_asm64(__val, ptr) do { \
205 __asm__ __volatile__ ( \
206 "1: stw %2,0(%%sr2,%1)\n" \
207 "2: stw %R2,4(%%sr2,%1)\n" \
208 "9:\n" \
209 ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 9b) \
210 ASM_EXCEPTIONTABLE_ENTRY_EFAULT(2b, 9b) \
211 : "=r"(__pu_err) \
212 : "r"(ptr), "r"(__val), "0"(__pu_err)); \
213 } while (0)
214
215 #endif /* !defined(CONFIG_64BIT) */
216
217
218 /*
219 * Complex access routines -- external declarations
220 */
221
222 extern unsigned long lcopy_to_user(void __user *, const void *, unsigned long);
223 extern unsigned long lcopy_from_user(void *, const void __user *, unsigned long);
224 extern unsigned long lcopy_in_user(void __user *, const void __user *, unsigned long);
225 extern long strncpy_from_user(char *, const char __user *, long);
226 extern unsigned lclear_user(void __user *, unsigned long);
227 extern long lstrnlen_user(const char __user *, long);
228 /*
229 * Complex access routines -- macros
230 */
231 #define user_addr_max() (~0UL)
232
233 #define strnlen_user lstrnlen_user
234 #define strlen_user(str) lstrnlen_user(str, 0x7fffffffL)
235 #define clear_user lclear_user
236 #define __clear_user lclear_user
237
238 unsigned long __must_check __copy_to_user(void __user *dst, const void *src,
239 unsigned long len);
240 unsigned long __must_check __copy_from_user(void *dst, const void __user *src,
241 unsigned long len);
242 unsigned long copy_in_user(void __user *dst, const void __user *src,
243 unsigned long len);
244 #define __copy_in_user copy_in_user
245 #define __copy_to_user_inatomic __copy_to_user
246 #define __copy_from_user_inatomic __copy_from_user
247
248 extern void __compiletime_error("usercopy buffer size is too small")
249 __bad_copy_user(void);
250
copy_user_overflow(int size,unsigned long count)251 static inline void copy_user_overflow(int size, unsigned long count)
252 {
253 WARN(1, "Buffer overflow detected (%d < %lu)!\n", size, count);
254 }
255
256 static __always_inline unsigned long __must_check
copy_from_user(void * to,const void __user * from,unsigned long n)257 copy_from_user(void *to, const void __user *from, unsigned long n)
258 {
259 int sz = __compiletime_object_size(to);
260 unsigned long ret = n;
261
262 if (likely(sz < 0 || sz >= n)) {
263 check_object_size(to, n, false);
264 ret = __copy_from_user(to, from, n);
265 } else if (!__builtin_constant_p(n))
266 copy_user_overflow(sz, n);
267 else
268 __bad_copy_user();
269
270 if (unlikely(ret))
271 memset(to + (n - ret), 0, ret);
272
273 return ret;
274 }
275
276 static __always_inline unsigned long __must_check
copy_to_user(void __user * to,const void * from,unsigned long n)277 copy_to_user(void __user *to, const void *from, unsigned long n)
278 {
279 int sz = __compiletime_object_size(from);
280
281 if (likely(sz < 0 || sz >= n)) {
282 check_object_size(from, n, true);
283 n = __copy_to_user(to, from, n);
284 } else if (!__builtin_constant_p(n))
285 copy_user_overflow(sz, n);
286 else
287 __bad_copy_user();
288
289 return n;
290 }
291
292 struct pt_regs;
293 int fixup_exception(struct pt_regs *regs);
294
295 #endif /* __PARISC_UACCESS_H */
296