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   1 /* $Id: uaccess.h,v 1.35 2002/02/09 19:49:31 davem Exp $ */
   2 #ifndef _ASM_UACCESS_H
   3 #define _ASM_UACCESS_H
   4
   5 /*
   6  * User space memory access functions
   7  */
   8
   9 #ifdef __KERNEL__
  10 #include <linux/compiler.h>
  11 #include <linux/sched.h>
  12 #include <linux/string.h>
  13 #include <asm/a.out.h>
  14 #include <asm/asi.h>
  15 #include <asm/system.h>
  16 #include <asm/spitfire.h>
  17 #include <asm-generic/uaccess.h>
  18 #endif
  19
  20 #ifndef __ASSEMBLY__
  21
  22 /*
  23  * Sparc64 is segmented, though more like the M68K than the I386.
  24  * We use the secondary ASI to address user memory, which references a
  25  * completely different VM map, thus there is zero chance of the user
  26  * doing something queer and tricking us into poking kernel memory.
  27  *
  28  * What is left here is basically what is needed for the other parts of
  29  * the kernel that expect to be able to manipulate, erum, "segments".
  30  * Or perhaps more properly, permissions.
  31  *
  32  * "For historical reasons, these macros are grossly misnamed." -Linus
  33  */
  34
  35 #define KERNEL_DS   ((mm_segment_t) { ASI_P })
  36 #define USER_DS     ((mm_segment_t) { ASI_AIUS })       /* har har har */
  37
  38 #define VERIFY_READ     0
  39 #define VERIFY_WRITE    1
  40
  41 #define get_fs() ((mm_segment_t) { get_thread_current_ds() })
  42 #define get_ds() (KERNEL_DS)
  43
  44 #define segment_eq(a,b)  ((a).seg == (b).seg)
  45
  46 #define set_fs(val)                                                             \
  47 do {                                                                            \
  48         set_thread_current_ds((val).seg);                                       \
  49         __asm__ __volatile__ ("wr %%g0, %0, %%asi" : : "r" ((val).seg));        \
  50 } while(0)
  51
  52 static inline int __access_ok(const void __user * addr, unsigned long size)
  53 {
  54         return 1;
  55 }
  56
  57 static inline int access_ok(int type, const void __user * addr, unsigned long size)
  58 {
  59         return 1;
  60 }
  61
  62 /*
  63  * The exception table consists of pairs of addresses: the first is the
  64  * address of an instruction that is allowed to fault, and the second is
  65  * the address at which the program should continue.  No registers are
  66  * modified, so it is entirely up to the continuation code to figure out
  67  * what to do.
  68  *
  69  * All the routines below use bits of fixup code that are out of line
  70  * with the main instruction path.  This means when everything is well,
  71  * we don't even have to jump over them.  Further, they do not intrude
  72  * on our cache or tlb entries.
  73  */
  74
  75 struct exception_table_entry {
  76         unsigned int insn, fixup;
  77 };
  78
  79 extern void __ret_efault(void);
  80 extern void __retl_efault(void);
  81
  82 /* Uh, these should become the main single-value transfer routines..
  83  * They automatically use the right size if we just have the right
  84  * pointer type..
  85  *
  86  * This gets kind of ugly. We want to return _two_ values in "get_user()"
  87  * and yet we don't want to do any pointers, because that is too much
  88  * of a performance impact. Thus we have a few rather ugly macros here,
  89  * and hide all the ugliness from the user.
  90  */
  91 #define put_user(x,ptr) ({ \
  92 unsigned long __pu_addr = (unsigned long)(ptr); \
  93 __chk_user_ptr(ptr); \
  94 __put_user_nocheck((__typeof__(*(ptr)))(x),__pu_addr,sizeof(*(ptr))); })
  95
  96 #define get_user(x,ptr) ({ \
  97 unsigned long __gu_addr = (unsigned long)(ptr); \
  98 __chk_user_ptr(ptr); \
  99 __get_user_nocheck((x),__gu_addr,sizeof(*(ptr)),__typeof__(*(ptr))); })
 100
 101 #define __put_user(x,ptr) put_user(x,ptr)
 102 #define __get_user(x,ptr) get_user(x,ptr)
 103
 104 struct __large_struct { unsigned long buf[100]; };
 105 #define __m(x) ((struct __large_struct *)(x))
 106
 107 #define __put_user_nocheck(data,addr,size) ({ \
 108 register int __pu_ret; \
 109 switch (size) { \
 110 case 1: __put_user_asm(data,b,addr,__pu_ret); break; \
 111 case 2: __put_user_asm(data,h,addr,__pu_ret); break; \
 112 case 4: __put_user_asm(data,w,addr,__pu_ret); break; \
 113 case 8: __put_user_asm(data,x,addr,__pu_ret); break; \
 114 default: __pu_ret = __put_user_bad(); break; \
 115 } __pu_ret; })
 116
 117 #define __put_user_asm(x,size,addr,ret)                                 \
 118 __asm__ __volatile__(                                                   \
 119         "/* Put user asm, inline. */\n"                                 \
 120 "1:\t"  "st"#size "a %1, [%2] %%asi\n\t"                                \
 121         "clr    %0\n"                                                   \
 122 "2:\n\n\t"                                                              \
 123         ".section .fixup,#alloc,#execinstr\n\t"                         \
 124         ".align 4\n"                                                    \
 125 "3:\n\t"                                                                \
 126         "sethi  %%hi(2b), %0\n\t"                                       \
 127         "jmpl   %0 + %%lo(2b), %%g0\n\t"                                \
 128         " mov   %3, %0\n\n\t"                                           \
 129         ".previous\n\t"                                                 \
 130         ".section __ex_table,\"a\"\n\t"                                 \
 131         ".align 4\n\t"                                                  \
 132         ".word  1b, 3b\n\t"                                             \
 133         ".previous\n\n\t"                                               \
 134        : "=r" (ret) : "r" (x), "r" (__m(addr)),                         \
 135          "i" (-EFAULT))
 136
 137 extern int __put_user_bad(void);
 138
 139 #define __get_user_nocheck(data,addr,size,type) ({ \
 140 register int __gu_ret; \
 141 register unsigned long __gu_val; \
 142 switch (size) { \
 143 case 1: __get_user_asm(__gu_val,ub,addr,__gu_ret); break; \
 144 case 2: __get_user_asm(__gu_val,uh,addr,__gu_ret); break; \
 145 case 4: __get_user_asm(__gu_val,uw,addr,__gu_ret); break; \
 146 case 8: __get_user_asm(__gu_val,x,addr,__gu_ret); break; \
 147 default: __gu_val = 0; __gu_ret = __get_user_bad(); break; \
 148 } data = (type) __gu_val; __gu_ret; })
 149
 150 #define __get_user_nocheck_ret(data,addr,size,type,retval) ({ \
 151 register unsigned long __gu_val __asm__ ("l1"); \
 152 switch (size) { \
 153 case 1: __get_user_asm_ret(__gu_val,ub,addr,retval); break; \
 154 case 2: __get_user_asm_ret(__gu_val,uh,addr,retval); break; \
 155 case 4: __get_user_asm_ret(__gu_val,uw,addr,retval); break; \
 156 case 8: __get_user_asm_ret(__gu_val,x,addr,retval); break; \
 157 default: if (__get_user_bad()) return retval; \
 158 } data = (type) __gu_val; })
 159
 160 #define __get_user_asm(x,size,addr,ret)                                 \
 161 __asm__ __volatile__(                                                   \
 162         "/* Get user asm, inline. */\n"                                 \
 163 "1:\t"  "ld"#size "a [%2] %%asi, %1\n\t"                                \
 164         "clr    %0\n"                                                   \
 165 "2:\n\n\t"                                                              \
 166         ".section .fixup,#alloc,#execinstr\n\t"                         \
 167         ".align 4\n"                                                    \
 168 "3:\n\t"                                                                \
 169         "sethi  %%hi(2b), %0\n\t"                                       \
 170         "clr    %1\n\t"                                                 \
 171         "jmpl   %0 + %%lo(2b), %%g0\n\t"                                \
 172         " mov   %3, %0\n\n\t"                                           \
 173         ".previous\n\t"                                                 \
 174         ".section __ex_table,\"a\"\n\t"                                 \
 175         ".align 4\n\t"                                                  \
 176         ".word  1b, 3b\n\n\t"                                           \
 177         ".previous\n\t"                                                 \
 178        : "=r" (ret), "=r" (x) : "r" (__m(addr)),                        \
 179          "i" (-EFAULT))
 180
 181 #define __get_user_asm_ret(x,size,addr,retval)                          \
 182 if (__builtin_constant_p(retval) && retval == -EFAULT)                  \
 183 __asm__ __volatile__(                                                   \
 184         "/* Get user asm ret, inline. */\n"                             \
 185 "1:\t"  "ld"#size "a [%1] %%asi, %0\n\n\t"                              \
 186         ".section __ex_table,\"a\"\n\t"                                 \
 187         ".align 4\n\t"                                                  \
 188         ".word  1b,__ret_efault\n\n\t"                                  \
 189         ".previous\n\t"                                                 \
 190        : "=r" (x) : "r" (__m(addr)));                                   \
 191 else                                                                    \
 192 __asm__ __volatile__(                                                   \
 193         "/* Get user asm ret, inline. */\n"                             \
 194 "1:\t"  "ld"#size "a [%1] %%asi, %0\n\n\t"                              \
 195         ".section .fixup,#alloc,#execinstr\n\t"                         \
 196         ".align 4\n"                                                    \
 197 "3:\n\t"                                                                \
 198         "ret\n\t"                                                       \
 199         " restore %%g0, %2, %%o0\n\n\t"                                 \
 200         ".previous\n\t"                                                 \
 201         ".section __ex_table,\"a\"\n\t"                                 \
 202         ".align 4\n\t"                                                  \
 203         ".word  1b, 3b\n\n\t"                                           \
 204         ".previous\n\t"                                                 \
 205        : "=r" (x) : "r" (__m(addr)), "i" (retval))
 206
 207 extern int __get_user_bad(void);
 208
 209 extern unsigned long __must_check ___copy_from_user(void *to,
 210                                                     const void __user *from,
 211                                                     unsigned long size);
 212 extern unsigned long copy_from_user_fixup(void *to, const void __user *from,
 213                                           unsigned long size);
 214 static inline unsigned long __must_check
 215 copy_from_user(void *to, const void __user *from, unsigned long size)
 216 {
 217         unsigned long ret = ___copy_from_user(to, from, size);
 218
 219         if (unlikely(ret))
 220                 ret = copy_from_user_fixup(to, from, size);
 221         return ret;
 222 }
 223 #define __copy_from_user copy_from_user
 224
 225 extern unsigned long __must_check ___copy_to_user(void __user *to,
 226                                                   const void *from,
 227                                                   unsigned long size);
 228 extern unsigned long copy_to_user_fixup(void __user *to, const void *from,
 229                                         unsigned long size);
 230 static inline unsigned long __must_check
 231 copy_to_user(void __user *to, const void *from, unsigned long size)
 232 {
 233         unsigned long ret = ___copy_to_user(to, from, size);
 234
 235         if (unlikely(ret))
 236                 ret = copy_to_user_fixup(to, from, size);
 237         return ret;
 238 }
 239 #define __copy_to_user copy_to_user
 240
 241 extern unsigned long __must_check ___copy_in_user(void __user *to,
 242                                                   const void __user *from,
 243                                                   unsigned long size);
 244 extern unsigned long copy_in_user_fixup(void __user *to, void __user *from,
 245                                         unsigned long size);
 246 static inline unsigned long __must_check
 247 copy_in_user(void __user *to, void __user *from, unsigned long size)
 248 {
 249         unsigned long ret = ___copy_in_user(to, from, size);
 250
 251         if (unlikely(ret))
 252                 ret = copy_in_user_fixup(to, from, size);
 253         return ret;
 254 }
 255 #define __copy_in_user copy_in_user
 256
 257 extern unsigned long __must_check __clear_user(void __user *, unsigned long);
 258
 259 #define clear_user __clear_user
 260
 261 extern long __must_check __strncpy_from_user(char *dest, const char __user *src, long count);
 262
 263 #define strncpy_from_user __strncpy_from_user
 264
 265 extern long __strlen_user(const char __user *);
 266 extern long __strnlen_user(const char __user *, long len);
 267
 268 #define strlen_user __strlen_user
 269 #define strnlen_user __strnlen_user
 270 #define __copy_to_user_inatomic __copy_to_user
 271 #define __copy_from_user_inatomic __copy_from_user
 272
 273 #endif  /* __ASSEMBLY__ */
 274
 275 #endif /* _ASM_UACCESS_H */