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