linux/arch/m68k/include/asm/uaccess_mm.h
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   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef __M68K_UACCESS_H
   3#define __M68K_UACCESS_H
   4
   5/*
   6 * User space memory access functions
   7 */
   8#include <linux/compiler.h>
   9#include <linux/types.h>
  10#include <asm/segment.h>
  11
  12/* We let the MMU do all checking */
  13static inline int access_ok(const void __user *addr,
  14                            unsigned long size)
  15{
  16        return 1;
  17}
  18
  19/*
  20 * Not all varients of the 68k family support the notion of address spaces.
  21 * The traditional 680x0 parts do, and they use the sfc/dfc registers and
  22 * the "moves" instruction to access user space from kernel space. Other
  23 * family members like ColdFire don't support this, and only have a single
  24 * address space, and use the usual "move" instruction for user space access.
  25 *
  26 * Outside of this difference the user space access functions are the same.
  27 * So lets keep the code simple and just define in what we need to use.
  28 */
  29#ifdef CONFIG_CPU_HAS_ADDRESS_SPACES
  30#define MOVES   "moves"
  31#else
  32#define MOVES   "move"
  33#endif
  34
  35extern int __put_user_bad(void);
  36extern int __get_user_bad(void);
  37
  38#define __put_user_asm(res, x, ptr, bwl, reg, err)      \
  39asm volatile ("\n"                                      \
  40        "1:     "MOVES"."#bwl"  %2,%1\n"                \
  41        "2:\n"                                          \
  42        "       .section .fixup,\"ax\"\n"               \
  43        "       .even\n"                                \
  44        "10:    moveq.l %3,%0\n"                        \
  45        "       jra 2b\n"                               \
  46        "       .previous\n"                            \
  47        "\n"                                            \
  48        "       .section __ex_table,\"a\"\n"            \
  49        "       .align  4\n"                            \
  50        "       .long   1b,10b\n"                       \
  51        "       .long   2b,10b\n"                       \
  52        "       .previous"                              \
  53        : "+d" (res), "=m" (*(ptr))                     \
  54        : #reg (x), "i" (err))
  55
  56/*
  57 * These are the main single-value transfer routines.  They automatically
  58 * use the right size if we just have the right pointer type.
  59 */
  60
  61#define __put_user(x, ptr)                                              \
  62({                                                                      \
  63        typeof(*(ptr)) __pu_val = (x);                                  \
  64        int __pu_err = 0;                                               \
  65        __chk_user_ptr(ptr);                                            \
  66        switch (sizeof (*(ptr))) {                                      \
  67        case 1:                                                         \
  68                __put_user_asm(__pu_err, __pu_val, ptr, b, d, -EFAULT); \
  69                break;                                                  \
  70        case 2:                                                         \
  71                __put_user_asm(__pu_err, __pu_val, ptr, w, r, -EFAULT); \
  72                break;                                                  \
  73        case 4:                                                         \
  74                __put_user_asm(__pu_err, __pu_val, ptr, l, r, -EFAULT); \
  75                break;                                                  \
  76        case 8:                                                         \
  77            {                                                           \
  78                const void __user *__pu_ptr = (ptr);                    \
  79                asm volatile ("\n"                                      \
  80                        "1:     "MOVES".l       %2,(%1)+\n"             \
  81                        "2:     "MOVES".l       %R2,(%1)\n"             \
  82                        "3:\n"                                          \
  83                        "       .section .fixup,\"ax\"\n"               \
  84                        "       .even\n"                                \
  85                        "10:    movel %3,%0\n"                          \
  86                        "       jra 3b\n"                               \
  87                        "       .previous\n"                            \
  88                        "\n"                                            \
  89                        "       .section __ex_table,\"a\"\n"            \
  90                        "       .align 4\n"                             \
  91                        "       .long 1b,10b\n"                         \
  92                        "       .long 2b,10b\n"                         \
  93                        "       .long 3b,10b\n"                         \
  94                        "       .previous"                              \
  95                        : "+d" (__pu_err), "+a" (__pu_ptr)              \
  96                        : "r" (__pu_val), "i" (-EFAULT)                 \
  97                        : "memory");                                    \
  98                break;                                                  \
  99            }                                                           \
 100        default:                                                        \
 101                __pu_err = __put_user_bad();                            \
 102                break;                                                  \
 103        }                                                               \
 104        __pu_err;                                                       \
 105})
 106#define put_user(x, ptr)        __put_user(x, ptr)
 107
 108
 109#define __get_user_asm(res, x, ptr, type, bwl, reg, err) ({             \
 110        type __gu_val;                                                  \
 111        asm volatile ("\n"                                              \
 112                "1:     "MOVES"."#bwl"  %2,%1\n"                        \
 113                "2:\n"                                                  \
 114                "       .section .fixup,\"ax\"\n"                       \
 115                "       .even\n"                                        \
 116                "10:    move.l  %3,%0\n"                                \
 117                "       sub.l   %1,%1\n"                                \
 118                "       jra     2b\n"                                   \
 119                "       .previous\n"                                    \
 120                "\n"                                                    \
 121                "       .section __ex_table,\"a\"\n"                    \
 122                "       .align  4\n"                                    \
 123                "       .long   1b,10b\n"                               \
 124                "       .previous"                                      \
 125                : "+d" (res), "=&" #reg (__gu_val)                      \
 126                : "m" (*(ptr)), "i" (err));                             \
 127        (x) = (__force typeof(*(ptr)))(__force unsigned long)__gu_val;  \
 128})
 129
 130#define __get_user(x, ptr)                                              \
 131({                                                                      \
 132        int __gu_err = 0;                                               \
 133        __chk_user_ptr(ptr);                                            \
 134        switch (sizeof(*(ptr))) {                                       \
 135        case 1:                                                         \
 136                __get_user_asm(__gu_err, x, ptr, u8, b, d, -EFAULT);    \
 137                break;                                                  \
 138        case 2:                                                         \
 139                __get_user_asm(__gu_err, x, ptr, u16, w, r, -EFAULT);   \
 140                break;                                                  \
 141        case 4:                                                         \
 142                __get_user_asm(__gu_err, x, ptr, u32, l, r, -EFAULT);   \
 143                break;                                                  \
 144        case 8: {                                                       \
 145                const void *__gu_ptr = (ptr);                           \
 146                union {                                                 \
 147                        u64 l;                                          \
 148                        __typeof__(*(ptr)) t;                           \
 149                } __gu_val;                                             \
 150                asm volatile ("\n"                                      \
 151                        "1:     "MOVES".l       (%2)+,%1\n"             \
 152                        "2:     "MOVES".l       (%2),%R1\n"             \
 153                        "3:\n"                                          \
 154                        "       .section .fixup,\"ax\"\n"               \
 155                        "       .even\n"                                \
 156                        "10:    move.l  %3,%0\n"                        \
 157                        "       sub.l   %1,%1\n"                        \
 158                        "       sub.l   %R1,%R1\n"                      \
 159                        "       jra     3b\n"                           \
 160                        "       .previous\n"                            \
 161                        "\n"                                            \
 162                        "       .section __ex_table,\"a\"\n"            \
 163                        "       .align  4\n"                            \
 164                        "       .long   1b,10b\n"                       \
 165                        "       .long   2b,10b\n"                       \
 166                        "       .previous"                              \
 167                        : "+d" (__gu_err), "=&r" (__gu_val.l),          \
 168                          "+a" (__gu_ptr)                               \
 169                        : "i" (-EFAULT)                                 \
 170                        : "memory");                                    \
 171                (x) = __gu_val.t;                                       \
 172                break;                                                  \
 173        }                                                               \
 174        default:                                                        \
 175                __gu_err = __get_user_bad();                            \
 176                break;                                                  \
 177        }                                                               \
 178        __gu_err;                                                       \
 179})
 180#define get_user(x, ptr) __get_user(x, ptr)
 181
 182unsigned long __generic_copy_from_user(void *to, const void __user *from, unsigned long n);
 183unsigned long __generic_copy_to_user(void __user *to, const void *from, unsigned long n);
 184
 185#define __suffix0
 186#define __suffix1 b
 187#define __suffix2 w
 188#define __suffix4 l
 189
 190#define ____constant_copy_from_user_asm(res, to, from, tmp, n1, n2, n3, s1, s2, s3)\
 191        asm volatile ("\n"                                              \
 192                "1:     "MOVES"."#s1"   (%2)+,%3\n"                     \
 193                "       move."#s1"      %3,(%1)+\n"                     \
 194                "       .ifnc   \""#s2"\",\"\"\n"                       \
 195                "2:     "MOVES"."#s2"   (%2)+,%3\n"                     \
 196                "       move."#s2"      %3,(%1)+\n"                     \
 197                "       .ifnc   \""#s3"\",\"\"\n"                       \
 198                "3:     "MOVES"."#s3"   (%2)+,%3\n"                     \
 199                "       move."#s3"      %3,(%1)+\n"                     \
 200                "       .endif\n"                                       \
 201                "       .endif\n"                                       \
 202                "4:\n"                                                  \
 203                "       .section __ex_table,\"a\"\n"                    \
 204                "       .align  4\n"                                    \
 205                "       .long   1b,10f\n"                               \
 206                "       .ifnc   \""#s2"\",\"\"\n"                       \
 207                "       .long   2b,20f\n"                               \
 208                "       .ifnc   \""#s3"\",\"\"\n"                       \
 209                "       .long   3b,30f\n"                               \
 210                "       .endif\n"                                       \
 211                "       .endif\n"                                       \
 212                "       .previous\n"                                    \
 213                "\n"                                                    \
 214                "       .section .fixup,\"ax\"\n"                       \
 215                "       .even\n"                                        \
 216                "10:    addq.l #"#n1",%0\n"                             \
 217                "       .ifnc   \""#s2"\",\"\"\n"                       \
 218                "20:    addq.l #"#n2",%0\n"                             \
 219                "       .ifnc   \""#s3"\",\"\"\n"                       \
 220                "30:    addq.l #"#n3",%0\n"                             \
 221                "       .endif\n"                                       \
 222                "       .endif\n"                                       \
 223                "       jra     4b\n"                                   \
 224                "       .previous\n"                                    \
 225                : "+d" (res), "+&a" (to), "+a" (from), "=&d" (tmp)      \
 226                : : "memory")
 227
 228#define ___constant_copy_from_user_asm(res, to, from, tmp, n1, n2, n3, s1, s2, s3)\
 229        ____constant_copy_from_user_asm(res, to, from, tmp, n1, n2, n3, s1, s2, s3)
 230#define __constant_copy_from_user_asm(res, to, from, tmp, n1, n2, n3)   \
 231        ___constant_copy_from_user_asm(res, to, from, tmp, n1, n2, n3,  \
 232                                        __suffix##n1, __suffix##n2, __suffix##n3)
 233
 234static __always_inline unsigned long
 235__constant_copy_from_user(void *to, const void __user *from, unsigned long n)
 236{
 237        unsigned long res = 0, tmp;
 238
 239        switch (n) {
 240        case 1:
 241                __constant_copy_from_user_asm(res, to, from, tmp, 1, 0, 0);
 242                break;
 243        case 2:
 244                __constant_copy_from_user_asm(res, to, from, tmp, 2, 0, 0);
 245                break;
 246        case 3:
 247                __constant_copy_from_user_asm(res, to, from, tmp, 2, 1, 0);
 248                break;
 249        case 4:
 250                __constant_copy_from_user_asm(res, to, from, tmp, 4, 0, 0);
 251                break;
 252        case 5:
 253                __constant_copy_from_user_asm(res, to, from, tmp, 4, 1, 0);
 254                break;
 255        case 6:
 256                __constant_copy_from_user_asm(res, to, from, tmp, 4, 2, 0);
 257                break;
 258        case 7:
 259                __constant_copy_from_user_asm(res, to, from, tmp, 4, 2, 1);
 260                break;
 261        case 8:
 262                __constant_copy_from_user_asm(res, to, from, tmp, 4, 4, 0);
 263                break;
 264        case 9:
 265                __constant_copy_from_user_asm(res, to, from, tmp, 4, 4, 1);
 266                break;
 267        case 10:
 268                __constant_copy_from_user_asm(res, to, from, tmp, 4, 4, 2);
 269                break;
 270        case 12:
 271                __constant_copy_from_user_asm(res, to, from, tmp, 4, 4, 4);
 272                break;
 273        default:
 274                /* we limit the inlined version to 3 moves */
 275                return __generic_copy_from_user(to, from, n);
 276        }
 277
 278        return res;
 279}
 280
 281#define __constant_copy_to_user_asm(res, to, from, tmp, n, s1, s2, s3)  \
 282        asm volatile ("\n"                                              \
 283                "       move."#s1"      (%2)+,%3\n"                     \
 284                "11:    "MOVES"."#s1"   %3,(%1)+\n"                     \
 285                "12:    move."#s2"      (%2)+,%3\n"                     \
 286                "21:    "MOVES"."#s2"   %3,(%1)+\n"                     \
 287                "22:\n"                                                 \
 288                "       .ifnc   \""#s3"\",\"\"\n"                       \
 289                "       move."#s3"      (%2)+,%3\n"                     \
 290                "31:    "MOVES"."#s3"   %3,(%1)+\n"                     \
 291                "32:\n"                                                 \
 292                "       .endif\n"                                       \
 293                "4:\n"                                                  \
 294                "\n"                                                    \
 295                "       .section __ex_table,\"a\"\n"                    \
 296                "       .align  4\n"                                    \
 297                "       .long   11b,5f\n"                               \
 298                "       .long   12b,5f\n"                               \
 299                "       .long   21b,5f\n"                               \
 300                "       .long   22b,5f\n"                               \
 301                "       .ifnc   \""#s3"\",\"\"\n"                       \
 302                "       .long   31b,5f\n"                               \
 303                "       .long   32b,5f\n"                               \
 304                "       .endif\n"                                       \
 305                "       .previous\n"                                    \
 306                "\n"                                                    \
 307                "       .section .fixup,\"ax\"\n"                       \
 308                "       .even\n"                                        \
 309                "5:     moveq.l #"#n",%0\n"                             \
 310                "       jra     4b\n"                                   \
 311                "       .previous\n"                                    \
 312                : "+d" (res), "+a" (to), "+a" (from), "=&d" (tmp)       \
 313                : : "memory")
 314
 315static __always_inline unsigned long
 316__constant_copy_to_user(void __user *to, const void *from, unsigned long n)
 317{
 318        unsigned long res = 0, tmp;
 319
 320        switch (n) {
 321        case 1:
 322                __put_user_asm(res, *(u8 *)from, (u8 __user *)to, b, d, 1);
 323                break;
 324        case 2:
 325                __put_user_asm(res, *(u16 *)from, (u16 __user *)to, w, r, 2);
 326                break;
 327        case 3:
 328                __constant_copy_to_user_asm(res, to, from, tmp, 3, w, b,);
 329                break;
 330        case 4:
 331                __put_user_asm(res, *(u32 *)from, (u32 __user *)to, l, r, 4);
 332                break;
 333        case 5:
 334                __constant_copy_to_user_asm(res, to, from, tmp, 5, l, b,);
 335                break;
 336        case 6:
 337                __constant_copy_to_user_asm(res, to, from, tmp, 6, l, w,);
 338                break;
 339        case 7:
 340                __constant_copy_to_user_asm(res, to, from, tmp, 7, l, w, b);
 341                break;
 342        case 8:
 343                __constant_copy_to_user_asm(res, to, from, tmp, 8, l, l,);
 344                break;
 345        case 9:
 346                __constant_copy_to_user_asm(res, to, from, tmp, 9, l, l, b);
 347                break;
 348        case 10:
 349                __constant_copy_to_user_asm(res, to, from, tmp, 10, l, l, w);
 350                break;
 351        case 12:
 352                __constant_copy_to_user_asm(res, to, from, tmp, 12, l, l, l);
 353                break;
 354        default:
 355                /* limit the inlined version to 3 moves */
 356                return __generic_copy_to_user(to, from, n);
 357        }
 358
 359        return res;
 360}
 361
 362static inline unsigned long
 363raw_copy_from_user(void *to, const void __user *from, unsigned long n)
 364{
 365        if (__builtin_constant_p(n))
 366                return __constant_copy_from_user(to, from, n);
 367        return __generic_copy_from_user(to, from, n);
 368}
 369
 370static inline unsigned long
 371raw_copy_to_user(void __user *to, const void *from, unsigned long n)
 372{
 373        if (__builtin_constant_p(n))
 374                return __constant_copy_to_user(to, from, n);
 375        return __generic_copy_to_user(to, from, n);
 376}
 377#define INLINE_COPY_FROM_USER
 378#define INLINE_COPY_TO_USER
 379
 380#define user_addr_max() \
 381        (uaccess_kernel() ? ~0UL : TASK_SIZE)
 382
 383extern long strncpy_from_user(char *dst, const char __user *src, long count);
 384extern __must_check long strnlen_user(const char __user *str, long n);
 385
 386unsigned long __clear_user(void __user *to, unsigned long n);
 387
 388#define clear_user      __clear_user
 389
 390#endif /* _M68K_UACCESS_H */
 391