arch/sparc/include/asm/uaccess_64.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _ASM_UACCESS_H
   3 #define _ASM_UACCESS_H
   4
   5 /*
   6  * User space memory access functions
   7  */
   8
   9 #include <linux/compiler.h>
  10 #include <linux/string.h>
  11 #include <asm/asi.h>
  12 #include <asm/spitfire.h>
  13 #include <asm/extable_64.h>
  14
  15 #include <asm/processor.h>
  16
  17 /*
  18  * Sparc64 is segmented, though more like the M68K than the I386.
  19  * We use the secondary ASI to address user memory, which references a
  20  * completely different VM map, thus there is zero chance of the user
  21  * doing something queer and tricking us into poking kernel memory.
  22  *
  23  * What is left here is basically what is needed for the other parts of
  24  * the kernel that expect to be able to manipulate, erum, "segments".
  25  * Or perhaps more properly, permissions.
  26  *
  27  * "For historical reasons, these macros are grossly misnamed." -Linus
  28  */
  29
  30 #define KERNEL_DS   ((mm_segment_t) { ASI_P })
  31 #define USER_DS     ((mm_segment_t) { ASI_AIUS })       /* har har har */
  32
  33 #define get_fs() ((mm_segment_t){(current_thread_info()->current_ds)})
  34
  35 #define segment_eq(a, b)  ((a).seg == (b).seg)
  36
  37 #define set_fs(val)                                                             \
  38 do {                                                                            \
  39         current_thread_info()->current_ds = (val).seg;                          \
  40         __asm__ __volatile__ ("wr %%g0, %0, %%asi" : : "r" ((val).seg));        \
  41 } while(0)
  42
  43 /*
  44  * Test whether a block of memory is a valid user space address.
  45  * Returns 0 if the range is valid, nonzero otherwise.
  46  */
  47 static inline bool __chk_range_not_ok(unsigned long addr, unsigned long size, unsigned long limit)
  48 {
  49         if (__builtin_constant_p(size))
  50                 return addr > limit - size;
  51
  52         addr += size;
  53         if (addr < size)
  54                 return true;
  55
  56         return addr > limit;
  57 }
  58
  59 #define __range_not_ok(addr, size, limit)                               \
  60 ({                                                                      \
  61         __chk_user_ptr(addr);                                           \
  62         __chk_range_not_ok((unsigned long __force)(addr), size, limit); \
  63 })
  64
  65 static inline int __access_ok(const void __user * addr, unsigned long size)
  66 {
  67         return 1;
  68 }
  69
  70 static inline int access_ok(const void __user * addr, unsigned long size)
  71 {
  72         return 1;
  73 }
  74
  75 void __retl_efault(void);
  76
  77 /* Uh, these should become the main single-value transfer routines..
  78  * They automatically use the right size if we just have the right
  79  * pointer type..
  80  *
  81  * This gets kind of ugly. We want to return _two_ values in "get_user()"
  82  * and yet we don't want to do any pointers, because that is too much
  83  * of a performance impact. Thus we have a few rather ugly macros here,
  84  * and hide all the ugliness from the user.
  85  */
  86 #define put_user(x, ptr) ({ \
  87         unsigned long __pu_addr = (unsigned long)(ptr); \
  88         __chk_user_ptr(ptr); \
  89         __put_user_nocheck((__typeof__(*(ptr)))(x), __pu_addr, sizeof(*(ptr)));\
  90 })
  91
  92 #define get_user(x, ptr) ({ \
  93         unsigned long __gu_addr = (unsigned long)(ptr); \
  94         __chk_user_ptr(ptr); \
  95         __get_user_nocheck((x), __gu_addr, sizeof(*(ptr)), __typeof__(*(ptr)));\
  96 })
  97
  98 #define __put_user(x, ptr) put_user(x, ptr)
  99 #define __get_user(x, ptr) get_user(x, ptr)
 100
 101 struct __large_struct { unsigned long buf[100]; };
 102 #define __m(x) ((struct __large_struct *)(x))
 103
 104 #define __put_user_nocheck(data, addr, size) ({                 \
 105         register int __pu_ret;                                  \
 106         switch (size) {                                         \
 107         case 1: __put_user_asm(data, b, addr, __pu_ret); break; \
 108         case 2: __put_user_asm(data, h, addr, __pu_ret); break; \
 109         case 4: __put_user_asm(data, w, addr, __pu_ret); break; \
 110         case 8: __put_user_asm(data, x, addr, __pu_ret); break; \
 111         default: __pu_ret = __put_user_bad(); break;            \
 112         }                                                       \
 113         __pu_ret;                                               \
 114 })
 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 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:                                                     \
 147                         __gu_val = 0;                                        \
 148                         __gu_ret = __get_user_bad();                         \
 149                         break;                                               \
 150         }                                                                    \
 151         data = (__force type) __gu_val;                                      \
 152          __gu_ret;                                                           \
 153 })
 154
 155 #define __get_user_asm(x, size, addr, ret)                              \
 156 __asm__ __volatile__(                                                   \
 157                 "/* Get user asm, inline. */\n"                         \
 158         "1:\t"  "ld"#size "a [%2] %%asi, %1\n\t"                        \
 159                 "clr    %0\n"                                           \
 160         "2:\n\n\t"                                                      \
 161                 ".section .fixup,#alloc,#execinstr\n\t"                 \
 162                 ".align 4\n"                                            \
 163         "3:\n\t"                                                        \
 164                 "sethi  %%hi(2b), %0\n\t"                               \
 165                 "clr    %1\n\t"                                         \
 166                 "jmpl   %0 + %%lo(2b), %%g0\n\t"                        \
 167                 " mov   %3, %0\n\n\t"                                   \
 168                 ".previous\n\t"                                         \
 169                 ".section __ex_table,\"a\"\n\t"                         \
 170                 ".align 4\n\t"                                          \
 171                 ".word  1b, 3b\n\n\t"                                   \
 172                 ".previous\n\t"                                         \
 173                : "=r" (ret), "=r" (x) : "r" (__m(addr)),                \
 174                  "i" (-EFAULT))
 175
 176 int __get_user_bad(void);
 177
 178 unsigned long __must_check raw_copy_from_user(void *to,
 179                                              const void __user *from,
 180                                              unsigned long size);
 181
 182 unsigned long __must_check raw_copy_to_user(void __user *to,
 183                                            const void *from,
 184                                            unsigned long size);
 185 #define INLINE_COPY_FROM_USER
 186 #define INLINE_COPY_TO_USER
 187
 188 unsigned long __must_check raw_copy_in_user(void __user *to,
 189                                            const void __user *from,
 190                                            unsigned long size);
 191
 192 unsigned long __must_check __clear_user(void __user *, unsigned long);
 193
 194 #define clear_user __clear_user
 195
 196 __must_check long strnlen_user(const char __user *str, long n);
 197
 198 struct pt_regs;
 199 unsigned long compute_effective_address(struct pt_regs *,
 200                                         unsigned int insn,
 201                                         unsigned int rd);
 202
 203 #endif /* _ASM_UACCESS_H */