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uaccess.h
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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>
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  */
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
261 
262  return ret;
263 }
264 
265 struct pt_regs;
266 int fixup_exception(struct pt_regs *regs);
267 
268 #endif /* __PARISC_UACCESS_H */