kernel/arch/sparc/include/asm/uaccess_64.h

   1 #ifndef _ASM_UACCESS_H
   2 #define _ASM_UACCESS_H
   3
   4 /*
   5  * User space memory access functions
   6  */
   7
   8 #ifdef __KERNEL__
   9 #include <linux/errno.h>
  10 #include <linux/compiler.h>
  11 #include <linux/string.h>
  12 #include <linux/thread_info.h>
  13 #include <asm/asi.h>
  14 #include <asm/spitfire.h>
  15 #include <asm-generic/uaccess-unaligned.h>
  16 #endif
  17
  18 #ifndef __ASSEMBLY__
  19
  20 #include <asm/processor.h>
  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){(current_thread_info()->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         current_thread_info()->current_ds = (val).seg;                          \
  49         __asm__ __volatile__ ("wr %%g0, %0, %%asi" : : "r" ((val).seg));        \
  50 } while(0)
  51
  52 /*
  53  * Test whether a block of memory is a valid user space address.
  54  * Returns 0 if the range is valid, nonzero otherwise.
  55  */
  56 static inline bool __chk_range_not_ok(unsigned long addr, unsigned long size, unsigned long limit)
  57 {
  58         if (__builtin_constant_p(size))
  59                 return addr > limit - size;
  60
  61         addr += size;
  62         if (addr < size)
  63                 return true;
  64
  65         return addr > limit;
  66 }
  67
  68 #define __range_not_ok(addr, size, limit)                               \
  69 ({                                                                      \
  70         __chk_user_ptr(addr);                                           \
  71         __chk_range_not_ok((unsigned long __force)(addr), size, limit); \
  72 })
  73
  74 static inline int __access_ok(const void __user * addr, unsigned long size)
  75 {
  76         return 1;
  77 }
  78
  79 static inline int access_ok(int type, const void __user * addr, unsigned long size)
  80 {
  81         return 1;
  82 }
  83
  84 /*
  85  * The exception table consists of pairs of addresses: the first is the
  86  * address of an instruction that is allowed to fault, and the second is
  87  * the address at which the program should continue.  No registers are
  88  * modified, so it is entirely up to the continuation code to figure out
  89  * what to do.
  90  *
  91  * All the routines below use bits of fixup code that are out of line
  92  * with the main instruction path.  This means when everything is well,
  93  * we don't even have to jump over them.  Further, they do not intrude
  94  * on our cache or tlb entries.
  95  */
  96
  97 struct exception_table_entry {
  98         unsigned int insn, fixup;
  99 };
 100
 101 void __retl_efault(void);
 102
 103 /* Uh, these should become the main single-value transfer routines..
 104  * They automatically use the right size if we just have the right
 105  * pointer type..
 106  *
 107  * This gets kind of ugly. We want to return _two_ values in "get_user()"
 108  * and yet we don't want to do any pointers, because that is too much
 109  * of a performance impact. Thus we have a few rather ugly macros here,
 110  * and hide all the ugliness from the user.
 111  */
 112 #define put_user(x, ptr) ({ \
 113         unsigned long __pu_addr = (unsigned long)(ptr); \
 114         __chk_user_ptr(ptr); \
 115         __put_user_nocheck((__typeof__(*(ptr)))(x), __pu_addr, sizeof(*(ptr)));\
 116 })
 117
 118 #define get_user(x, ptr) ({ \
 119         unsigned long __gu_addr = (unsigned long)(ptr); \
 120         __chk_user_ptr(ptr); \
 121         __get_user_nocheck((x), __gu_addr, sizeof(*(ptr)), __typeof__(*(ptr)));\
 122 })
 123
 124 #define __put_user(x, ptr) put_user(x, ptr)
 125 #define __get_user(x, ptr) get_user(x, ptr)
 126
 127 struct __large_struct { unsigned long buf[100]; };
 128 #define __m(x) ((struct __large_struct *)(x))
 129
 130 #define __put_user_nocheck(data, addr, size) ({                 \
 131         register int __pu_ret;                                  \
 132         switch (size) {                                         \
 133         case 1: __put_user_asm(data, b, addr, __pu_ret); break; \
 134         case 2: __put_user_asm(data, h, addr, __pu_ret); break; \
 135         case 4: __put_user_asm(data, w, addr, __pu_ret); break; \
 136         case 8: __put_user_asm(data, x, addr, __pu_ret); break; \
 137         default: __pu_ret = __put_user_bad(); break;            \
 138         }                                                       \
 139         __pu_ret;                                               \
 140 })
 141
 142 #define __put_user_asm(x, size, addr, ret)                              \
 143 __asm__ __volatile__(                                                   \
 144                 "/* Put user asm, inline. */\n"                         \
 145         "1:\t"  "st"#size "a %1, [%2] %%asi\n\t"                        \
 146                 "clr    %0\n"                                           \
 147         "2:\n\n\t"                                                      \
 148                 ".section .fixup,#alloc,#execinstr\n\t"                 \
 149                 ".align 4\n"                                            \
 150         "3:\n\t"                                                        \
 151                 "sethi  %%hi(2b), %0\n\t"                               \
 152                 "jmpl   %0 + %%lo(2b), %%g0\n\t"                        \
 153                 " mov   %3, %0\n\n\t"                                   \
 154                 ".previous\n\t"                                         \
 155                 ".section __ex_table,\"a\"\n\t"                         \
 156                 ".align 4\n\t"                                          \
 157                 ".word  1b, 3b\n\t"                                     \
 158                 ".previous\n\n\t"                                       \
 159                : "=r" (ret) : "r" (x), "r" (__m(addr)),                 \
 160                  "i" (-EFAULT))
 161
 162 int __put_user_bad(void);
 163
 164 #define __get_user_nocheck(data, addr, size, type) ({                        \
 165         register int __gu_ret;                                               \
 166         register unsigned long __gu_val;                                     \
 167         switch (size) {                                                      \
 168                 case 1: __get_user_asm(__gu_val, ub, addr, __gu_ret); break; \
 169                 case 2: __get_user_asm(__gu_val, uh, addr, __gu_ret); break; \
 170                 case 4: __get_user_asm(__gu_val, uw, addr, __gu_ret); break; \
 171                 case 8: __get_user_asm(__gu_val, x, addr, __gu_ret); break;  \
 172                 default:                                                     \
 173                         __gu_val = 0;                                        \
 174                         __gu_ret = __get_user_bad();                         \
 175                         break;                                               \
 176         }                                                                    \
 177         data = (__force type) __gu_val;                                      \
 178          __gu_ret;                                                           \
 179 })
 180
 181 #define __get_user_asm(x, size, addr, ret)                              \
 182 __asm__ __volatile__(                                                   \
 183                 "/* Get user asm, inline. */\n"                         \
 184         "1:\t"  "ld"#size "a [%2] %%asi, %1\n\t"                        \
 185                 "clr    %0\n"                                           \
 186         "2:\n\n\t"                                                      \
 187                 ".section .fixup,#alloc,#execinstr\n\t"                 \
 188                 ".align 4\n"                                            \
 189         "3:\n\t"                                                        \
 190                 "sethi  %%hi(2b), %0\n\t"                               \
 191                 "clr    %1\n\t"                                         \
 192                 "jmpl   %0 + %%lo(2b), %%g0\n\t"                        \
 193                 " mov   %3, %0\n\n\t"                                   \
 194                 ".previous\n\t"                                         \
 195                 ".section __ex_table,\"a\"\n\t"                         \
 196                 ".align 4\n\t"                                          \
 197                 ".word  1b, 3b\n\n\t"                                   \
 198                 ".previous\n\t"                                         \
 199                : "=r" (ret), "=r" (x) : "r" (__m(addr)),                \
 200                  "i" (-EFAULT))
 201
 202 int __get_user_bad(void);
 203
 204 unsigned long __must_check ___copy_from_user(void *to,
 205                                              const void __user *from,
 206                                              unsigned long size);
 207 static inline unsigned long __must_check
 208 copy_from_user(void *to, const void __user *from, unsigned long size)
 209 {
 210         return ___copy_from_user(to, from, size);
 211 }
 212 #define __copy_from_user copy_from_user
 213
 214 unsigned long __must_check ___copy_to_user(void __user *to,
 215                                            const void *from,
 216                                            unsigned long size);
 217 static inline unsigned long __must_check
 218 copy_to_user(void __user *to, const void *from, unsigned long size)
 219 {
 220         return ___copy_to_user(to, from, size);
 221 }
 222 #define __copy_to_user copy_to_user
 223
 224 unsigned long __must_check ___copy_in_user(void __user *to,
 225                                            const void __user *from,
 226                                            unsigned long size);
 227 static inline unsigned long __must_check
 228 copy_in_user(void __user *to, void __user *from, unsigned long size)
 229 {
 230         return ___copy_in_user(to, from, size);
 231 }
 232 #define __copy_in_user copy_in_user
 233
 234 unsigned long __must_check __clear_user(void __user *, unsigned long);
 235
 236 #define clear_user __clear_user
 237
 238 __must_check long strlen_user(const char __user *str);
 239 __must_check long strnlen_user(const char __user *str, long n);
 240
 241 #define __copy_to_user_inatomic __copy_to_user
 242 #define __copy_from_user_inatomic __copy_from_user
 243
 244 struct pt_regs;
 245 unsigned long compute_effective_address(struct pt_regs *,
 246                                         unsigned int insn,
 247                                         unsigned int rd);
 248
 249 #endif  /* __ASSEMBLY__ */
 250
 251 #endif /* _ASM_UACCESS_H */