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
  14 #include <asm/processor.h>
  15
  16 /*
  17  * Sparc64 is segmented, though more like the M68K than the I386.
  18  * We use the secondary ASI to address user memory, which references a
  19  * completely different VM map, thus there is zero chance of the user
  20  * doing something queer and tricking us into poking kernel memory.
  21  *
  22  * What is left here is basically what is needed for the other parts of
  23  * the kernel that expect to be able to manipulate, erum, "segments".
  24  * Or perhaps more properly, permissions.
  25  *
  26  * "For historical reasons, these macros are grossly misnamed." -Linus
  27  */
  28
  29 #define KERNEL_DS   ((mm_segment_t) { ASI_P })
  30 #define USER_DS     ((mm_segment_t) { ASI_AIUS })       /* har har har */
  31
  32 #define get_fs() ((mm_segment_t){(current_thread_info()->current_ds)})
  33
  34 #define uaccess_kernel() (get_fs().seg == KERNEL_DS.seg)
  35
  36 #define set_fs(val)                                                             \
  37 do {                                                                            \
  38         current_thread_info()->current_ds = (val).seg;                          \
  39         __asm__ __volatile__ ("wr %%g0, %0, %%asi" : : "r" ((val).seg));        \
  40 } while(0)
  41
  42 /*
  43  * Test whether a block of memory is a valid user space address.
  44  * Returns 0 if the range is valid, nonzero otherwise.
  45  */
  46 static inline bool __chk_range_not_ok(unsigned long addr, unsigned long size, unsigned long limit)
  47 {
  48         if (__builtin_constant_p(size))
  49                 return addr > limit - size;
  50
  51         addr += size;
  52         if (addr < size)
  53                 return true;
  54
  55         return addr > limit;
  56 }
  57
  58 #define __range_not_ok(addr, size, limit)                               \
  59 ({                                                                      \
  60         __chk_user_ptr(addr);                                           \
  61         __chk_range_not_ok((unsigned long __force)(addr), size, limit); \
  62 })
  63
  64 static inline int __access_ok(const void __user * addr, unsigned long size)
  65 {
  66         return 1;
  67 }
  68
  69 static inline int access_ok(const void __user * addr, unsigned long size)
  70 {
  71         return 1;
  72 }
  73
  74 void __retl_efault(void);
  75
  76 /* Uh, these should become the main single-value transfer routines..
  77  * They automatically use the right size if we just have the right
  78  * pointer type..
  79  *
  80  * This gets kind of ugly. We want to return _two_ values in "get_user()"
  81  * and yet we don't want to do any pointers, because that is too much
  82  * of a performance impact. Thus we have a few rather ugly macros here,
  83  * and hide all the ugliness from the user.
  84  */
  85 #define put_user(x, ptr) ({ \
  86         unsigned long __pu_addr = (unsigned long)(ptr); \
  87         __chk_user_ptr(ptr); \
  88         __put_user_nocheck((__typeof__(*(ptr)))(x), __pu_addr, sizeof(*(ptr)));\
  89 })
  90
  91 #define get_user(x, ptr) ({ \
  92         unsigned long __gu_addr = (unsigned long)(ptr); \
  93         __chk_user_ptr(ptr); \
  94         __get_user_nocheck((x), __gu_addr, sizeof(*(ptr)), __typeof__(*(ptr)));\
  95 })
  96
  97 #define __put_user(x, ptr) put_user(x, ptr)
  98 #define __get_user(x, ptr) get_user(x, ptr)
  99
 100 struct __large_struct { unsigned long buf[100]; };
 101 #define __m(x) ((struct __large_struct *)(x))
 102
 103 #define __put_user_nocheck(data, addr, size) ({                 \
 104         register int __pu_ret;                                  \
 105         switch (size) {                                         \
 106         case 1: __put_user_asm(data, b, addr, __pu_ret); break; \
 107         case 2: __put_user_asm(data, h, addr, __pu_ret); break; \
 108         case 4: __put_user_asm(data, w, addr, __pu_ret); break; \
 109         case 8: __put_user_asm(data, x, addr, __pu_ret); break; \
 110         default: __pu_ret = __put_user_bad(); break;            \
 111         }                                                       \
 112         __pu_ret;                                               \
 113 })
 114
 115 #define __put_user_asm(x, size, addr, ret)                              \
 116 __asm__ __volatile__(                                                   \
 117                 "/* Put user asm, inline. */\n"                         \
 118         "1:\t"  "st"#size "a %1, [%2] %%asi\n\t"                        \
 119                 "clr    %0\n"                                           \
 120         "2:\n\n\t"                                                      \
 121                 ".section .fixup,#alloc,#execinstr\n\t"                 \
 122                 ".align 4\n"                                            \
 123         "3:\n\t"                                                        \
 124                 "sethi  %%hi(2b), %0\n\t"                               \
 125                 "jmpl   %0 + %%lo(2b), %%g0\n\t"                        \
 126                 " mov   %3, %0\n\n\t"                                   \
 127                 ".previous\n\t"                                         \
 128                 ".section __ex_table,\"a\"\n\t"                         \
 129                 ".align 4\n\t"                                          \
 130                 ".word  1b, 3b\n\t"                                     \
 131                 ".previous\n\n\t"                                       \
 132                : "=r" (ret) : "r" (x), "r" (__m(addr)),                 \
 133                  "i" (-EFAULT))
 134
 135 int __put_user_bad(void);
 136
 137 #define __get_user_nocheck(data, addr, size, type) ({                        \
 138         register int __gu_ret;                                               \
 139         register unsigned long __gu_val;                                     \
 140         switch (size) {                                                      \
 141                 case 1: __get_user_asm(__gu_val, ub, addr, __gu_ret); break; \
 142                 case 2: __get_user_asm(__gu_val, uh, addr, __gu_ret); break; \
 143                 case 4: __get_user_asm(__gu_val, uw, addr, __gu_ret); break; \
 144                 case 8: __get_user_asm(__gu_val, x, addr, __gu_ret); break;  \
 145                 default:                                                     \
 146                         __gu_val = 0;                                        \
 147                         __gu_ret = __get_user_bad();                         \
 148                         break;                                               \
 149         }                                                                    \
 150         data = (__force type) __gu_val;                                      \
 151          __gu_ret;                                                           \
 152 })
 153
 154 #define __get_user_asm(x, size, addr, ret)                              \
 155 __asm__ __volatile__(                                                   \
 156                 "/* Get user asm, inline. */\n"                         \
 157         "1:\t"  "ld"#size "a [%2] %%asi, %1\n\t"                        \
 158                 "clr    %0\n"                                           \
 159         "2:\n\n\t"                                                      \
 160                 ".section .fixup,#alloc,#execinstr\n\t"                 \
 161                 ".align 4\n"                                            \
 162         "3:\n\t"                                                        \
 163                 "sethi  %%hi(2b), %0\n\t"                               \
 164                 "clr    %1\n\t"                                         \
 165                 "jmpl   %0 + %%lo(2b), %%g0\n\t"                        \
 166                 " mov   %3, %0\n\n\t"                                   \
 167                 ".previous\n\t"                                         \
 168                 ".section __ex_table,\"a\"\n\t"                         \
 169                 ".align 4\n\t"                                          \
 170                 ".word  1b, 3b\n\n\t"                                   \
 171                 ".previous\n\t"                                         \
 172                : "=r" (ret), "=r" (x) : "r" (__m(addr)),                \
 173                  "i" (-EFAULT))
 174
 175 int __get_user_bad(void);
 176
 177 unsigned long __must_check raw_copy_from_user(void *to,
 178                                              const void __user *from,
 179                                              unsigned long size);
 180
 181 unsigned long __must_check raw_copy_to_user(void __user *to,
 182                                            const void *from,
 183                                            unsigned long size);
 184 #define INLINE_COPY_FROM_USER
 185 #define INLINE_COPY_TO_USER
 186
 187 unsigned long __must_check raw_copy_in_user(void __user *to,
 188                                            const void __user *from,
 189                                            unsigned long size);
 190
 191 unsigned long __must_check __clear_user(void __user *, unsigned long);
 192
 193 #define clear_user __clear_user
 194
 195 __must_check long strnlen_user(const char __user *str, long n);
 196
 197 struct pt_regs;
 198 unsigned long compute_effective_address(struct pt_regs *,
 199                                         unsigned int insn,
 200                                         unsigned int rd);
 201
 202 #endif /* _ASM_UACCESS_H */