arch/m32r/lib/usercopy.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * User address space access functions.
   4  * The non inlined parts of asm-m32r/uaccess.h are here.
   5  *
   6  * Copyright 1997 Andi Kleen <ak@muc.de>
   7  * Copyright 1997 Linus Torvalds
   8  * Copyright 2001, 2002, 2004 Hirokazu Takata
   9  */
  10 #include <linux/prefetch.h>
  11 #include <linux/string.h>
  12 #include <linux/thread_info.h>
  13 #include <linux/uaccess.h>
  14
  15 /*
  16  * Copy a null terminated string from userspace.
  17  */
  18
  19 #ifdef CONFIG_ISA_DUAL_ISSUE
  20
  21 #define __do_strncpy_from_user(dst,src,count,res)                       \
  22 do {                                                                    \
  23         int __d0, __d1, __d2;                                           \
  24         __asm__ __volatile__(                                           \
  25                 "       beqz    %1, 2f\n"                               \
  26                 "       .fillinsn\n"                                    \
  27                 "0:     ldb     r14, @%3    ||  addi    %3, #1\n"       \
  28                 "       stb     r14, @%4    ||  addi    %4, #1\n"       \
  29                 "       beqz    r14, 1f\n"                              \
  30                 "       addi    %1, #-1\n"                              \
  31                 "       bnez    %1, 0b\n"                               \
  32                 "       .fillinsn\n"                                    \
  33                 "1:     sub     %0, %1\n"                               \
  34                 "       .fillinsn\n"                                    \
  35                 "2:\n"                                                  \
  36                 ".section .fixup,\"ax\"\n"                              \
  37                 "       .balign 4\n"                                    \
  38                 "3:     seth    r14, #high(2b)\n"                       \
  39                 "       or3     r14, r14, #low(2b)\n"                   \
  40                 "       jmp     r14         ||  ldi     %0, #%5\n"      \
  41                 ".previous\n"                                           \
  42                 ".section __ex_table,\"a\"\n"                           \
  43                 "       .balign 4\n"                                    \
  44                 "       .long 0b,3b\n"                                  \
  45                 ".previous"                                             \
  46                 : "=&r"(res), "=&r"(count), "=&r" (__d0), "=&r" (__d1), \
  47                   "=&r" (__d2)                                          \
  48                 : "i"(-EFAULT), "0"(count), "1"(count), "3"(src),       \
  49                   "4"(dst)                                              \
  50                 : "r14", "cbit", "memory");                             \
  51 } while (0)
  52
  53 #else /* not CONFIG_ISA_DUAL_ISSUE */
  54
  55 #define __do_strncpy_from_user(dst,src,count,res)                       \
  56 do {                                                                    \
  57         int __d0, __d1, __d2;                                           \
  58         __asm__ __volatile__(                                           \
  59                 "       beqz    %1, 2f\n"                               \
  60                 "       .fillinsn\n"                                    \
  61                 "0:     ldb     r14, @%3\n"                             \
  62                 "       stb     r14, @%4\n"                             \
  63                 "       addi    %3, #1\n"                               \
  64                 "       addi    %4, #1\n"                               \
  65                 "       beqz    r14, 1f\n"                              \
  66                 "       addi    %1, #-1\n"                              \
  67                 "       bnez    %1, 0b\n"                               \
  68                 "       .fillinsn\n"                                    \
  69                 "1:     sub     %0, %1\n"                               \
  70                 "       .fillinsn\n"                                    \
  71                 "2:\n"                                                  \
  72                 ".section .fixup,\"ax\"\n"                              \
  73                 "       .balign 4\n"                                    \
  74                 "3:     ldi     %0, #%5\n"                              \
  75                 "       seth    r14, #high(2b)\n"                       \
  76                 "       or3     r14, r14, #low(2b)\n"                   \
  77                 "       jmp     r14\n"                                  \
  78                 ".previous\n"                                           \
  79                 ".section __ex_table,\"a\"\n"                           \
  80                 "       .balign 4\n"                                    \
  81                 "       .long 0b,3b\n"                                  \
  82                 ".previous"                                             \
  83                 : "=&r"(res), "=&r"(count), "=&r" (__d0), "=&r" (__d1), \
  84                   "=&r" (__d2)                                          \
  85                 : "i"(-EFAULT), "0"(count), "1"(count), "3"(src),       \
  86                   "4"(dst)                                              \
  87                 : "r14", "cbit", "memory");                             \
  88 } while (0)
  89
  90 #endif /* CONFIG_ISA_DUAL_ISSUE */
  91
  92 long
  93 strncpy_from_user(char *dst, const char __user *src, long count)
  94 {
  95         long res = -EFAULT;
  96         if (access_ok(VERIFY_READ, src, 1))
  97                 __do_strncpy_from_user(dst, src, count, res);
  98         return res;
  99 }
 100
 101
 102 /*
 103  * Zero Userspace
 104  */
 105
 106 #ifdef CONFIG_ISA_DUAL_ISSUE
 107
 108 #define __do_clear_user(addr,size)                                      \
 109 do {                                                                    \
 110         int __dst, __c;                                                 \
 111         __asm__ __volatile__(                                           \
 112                 "       beqz    %1, 9f\n"                               \
 113                 "       and3    r14, %0, #3\n"                          \
 114                 "       bnez    r14, 2f\n"                              \
 115                 "       and3    r14, %1, #3\n"                          \
 116                 "       bnez    r14, 2f\n"                              \
 117                 "       and3    %1, %1, #3\n"                           \
 118                 "       beqz    %2, 2f\n"                               \
 119                 "       addi    %0, #-4\n"                              \
 120                 "       .fillinsn\n"                                    \
 121                 "0:     ; word clear \n"                                \
 122                 "       st      %6, @+%0    ||  addi    %2, #-1\n"      \
 123                 "       bnez    %2, 0b\n"                               \
 124                 "       beqz    %1, 9f\n"                               \
 125                 "       .fillinsn\n"                                    \
 126                 "2:     ; byte clear \n"                                \
 127                 "       stb     %6, @%0     ||  addi    %1, #-1\n"      \
 128                 "       addi    %0, #1\n"                               \
 129                 "       bnez    %1, 2b\n"                               \
 130                 "       .fillinsn\n"                                    \
 131                 "9:\n"                                                  \
 132                 ".section .fixup,\"ax\"\n"                              \
 133                 "       .balign 4\n"                                    \
 134                 "4:     slli    %2, #2\n"                               \
 135                 "       seth    r14, #high(9b)\n"                       \
 136                 "       or3     r14, r14, #low(9b)\n"                   \
 137                 "       jmp     r14         ||  add     %1, %2\n"       \
 138                 ".previous\n"                                           \
 139                 ".section __ex_table,\"a\"\n"                           \
 140                 "       .balign 4\n"                                    \
 141                 "       .long 0b,4b\n"                                  \
 142                 "       .long 2b,9b\n"                                  \
 143                 ".previous\n"                                           \
 144                 : "=&r"(__dst), "=&r"(size), "=&r"(__c)                 \
 145                 : "0"(addr), "1"(size), "2"(size / 4), "r"(0)           \
 146                 : "r14", "cbit", "memory");                             \
 147 } while (0)
 148
 149 #else /* not CONFIG_ISA_DUAL_ISSUE */
 150
 151 #define __do_clear_user(addr,size)                                      \
 152 do {                                                                    \
 153         int __dst, __c;                                                 \
 154         __asm__ __volatile__(                                           \
 155                 "       beqz    %1, 9f\n"                               \
 156                 "       and3    r14, %0, #3\n"                          \
 157                 "       bnez    r14, 2f\n"                              \
 158                 "       and3    r14, %1, #3\n"                          \
 159                 "       bnez    r14, 2f\n"                              \
 160                 "       and3    %1, %1, #3\n"                           \
 161                 "       beqz    %2, 2f\n"                               \
 162                 "       addi    %0, #-4\n"                              \
 163                 "       .fillinsn\n"                                    \
 164                 "0:     st      %6, @+%0        ; word clear \n"        \
 165                 "       addi    %2, #-1\n"                              \
 166                 "       bnez    %2, 0b\n"                               \
 167                 "       beqz    %1, 9f\n"                               \
 168                 "       .fillinsn\n"                                    \
 169                 "2:     stb     %6, @%0         ; byte clear \n"        \
 170                 "       addi    %1, #-1\n"                              \
 171                 "       addi    %0, #1\n"                               \
 172                 "       bnez    %1, 2b\n"                               \
 173                 "       .fillinsn\n"                                    \
 174                 "9:\n"                                                  \
 175                 ".section .fixup,\"ax\"\n"                              \
 176                 "       .balign 4\n"                                    \
 177                 "4:     slli    %2, #2\n"                               \
 178                 "       add     %1, %2\n"                               \
 179                 "       seth    r14, #high(9b)\n"                       \
 180                 "       or3     r14, r14, #low(9b)\n"                   \
 181                 "       jmp     r14\n"                                  \
 182                 ".previous\n"                                           \
 183                 ".section __ex_table,\"a\"\n"                           \
 184                 "       .balign 4\n"                                    \
 185                 "       .long 0b,4b\n"                                  \
 186                 "       .long 2b,9b\n"                                  \
 187                 ".previous\n"                                           \
 188                 : "=&r"(__dst), "=&r"(size), "=&r"(__c)                 \
 189                 : "0"(addr), "1"(size), "2"(size / 4), "r"(0)           \
 190                 : "r14", "cbit", "memory");                             \
 191 } while (0)
 192
 193 #endif /* not CONFIG_ISA_DUAL_ISSUE */
 194
 195 unsigned long
 196 clear_user(void __user *to, unsigned long n)
 197 {
 198         if (access_ok(VERIFY_WRITE, to, n))
 199                 __do_clear_user(to, n);
 200         return n;
 201 }
 202
 203 unsigned long
 204 __clear_user(void __user *to, unsigned long n)
 205 {
 206         __do_clear_user(to, n);
 207         return n;
 208 }
 209
 210 /*
 211  * Return the size of a string (including the ending 0)
 212  *
 213  * Return 0 on exception, a value greater than N if too long
 214  */
 215
 216 #ifdef CONFIG_ISA_DUAL_ISSUE
 217
 218 long strnlen_user(const char __user *s, long n)
 219 {
 220         unsigned long mask = -__addr_ok(s);
 221         unsigned long res;
 222
 223         __asm__ __volatile__(
 224                 "       and     %0, %5      ||  mv      r1, %1\n"
 225                 "       beqz    %0, strnlen_exit\n"
 226                 "       and3    r0, %1, #3\n"
 227                 "       bnez    r0, strnlen_byte_loop\n"
 228                 "       cmpui   %0, #4\n"
 229                 "       bc      strnlen_byte_loop\n"
 230                 "strnlen_word_loop:\n"
 231                 "0:     ld      r0, @%1+\n"
 232                 "       pcmpbz  r0\n"
 233                 "       bc      strnlen_last_bytes_fixup\n"
 234                 "       addi    %0, #-4\n"
 235                 "       beqz    %0, strnlen_exit\n"
 236                 "       bgtz    %0, strnlen_word_loop\n"
 237                 "strnlen_last_bytes:\n"
 238                 "       mv      %0, %4\n"
 239                 "strnlen_last_bytes_fixup:\n"
 240                 "       addi    %1, #-4\n"
 241                 "strnlen_byte_loop:\n"
 242                 "1:     ldb     r0, @%1     ||  addi    %0, #-1\n"
 243                 "       beqz    r0, strnlen_exit\n"
 244                 "       addi    %1, #1\n"
 245                 "       bnez    %0, strnlen_byte_loop\n"
 246                 "strnlen_exit:\n"
 247                 "       sub     %1, r1\n"
 248                 "       add3    %0, %1, #1\n"
 249                 "       .fillinsn\n"
 250                 "9:\n"
 251                 ".section .fixup,\"ax\"\n"
 252                 "       .balign 4\n"
 253                 "4:     addi    %1, #-4\n"
 254                 "       .fillinsn\n"
 255                 "5:     seth    r1, #high(9b)\n"
 256                 "       or3     r1, r1, #low(9b)\n"
 257                 "       jmp     r1          ||  ldi     %0, #0\n"
 258                 ".previous\n"
 259                 ".section __ex_table,\"a\"\n"
 260                 "       .balign 4\n"
 261                 "       .long 0b,4b\n"
 262                 "       .long 1b,5b\n"
 263                 ".previous"
 264                 : "=&r" (res), "=r" (s)
 265                 : "0" (n), "1" (s), "r" (n & 3), "r" (mask), "r"(0x01010101)
 266                 : "r0", "r1", "cbit");
 267
 268         /* NOTE: strnlen_user() algorithm:
 269          * {
 270          *   char *p;
 271          *   for (p = s; n-- && *p != '\0'; ++p)
 272          *     ;
 273          *   return p - s + 1;
 274          * }
 275          */
 276
 277         /* NOTE: If a null char. exists, return 0.
 278          * if ((x - 0x01010101) & ~x & 0x80808080)\n"
 279          *   return 0;\n"
 280          */
 281
 282         return res & mask;
 283 }
 284
 285 #else /* not CONFIG_ISA_DUAL_ISSUE */
 286
 287 long strnlen_user(const char __user *s, long n)
 288 {
 289         unsigned long mask = -__addr_ok(s);
 290         unsigned long res;
 291
 292         __asm__ __volatile__(
 293                 "       and     %0, %5\n"
 294                 "       mv      r1, %1\n"
 295                 "       beqz    %0, strnlen_exit\n"
 296                 "       and3    r0, %1, #3\n"
 297                 "       bnez    r0, strnlen_byte_loop\n"
 298                 "       cmpui   %0, #4\n"
 299                 "       bc      strnlen_byte_loop\n"
 300                 "       sll3    r3, %6, #7\n"
 301                 "strnlen_word_loop:\n"
 302                 "0:     ld      r0, @%1+\n"
 303                 "       not     r2, r0\n"
 304                 "       sub     r0, %6\n"
 305                 "       and     r2, r3\n"
 306                 "       and     r2, r0\n"
 307                 "       bnez    r2, strnlen_last_bytes_fixup\n"
 308                 "       addi    %0, #-4\n"
 309                 "       beqz    %0, strnlen_exit\n"
 310                 "       bgtz    %0, strnlen_word_loop\n"
 311                 "strnlen_last_bytes:\n"
 312                 "       mv      %0, %4\n"
 313                 "strnlen_last_bytes_fixup:\n"
 314                 "       addi    %1, #-4\n"
 315                 "strnlen_byte_loop:\n"
 316                 "1:     ldb     r0, @%1\n"
 317                 "       addi    %0, #-1\n"
 318                 "       beqz    r0, strnlen_exit\n"
 319                 "       addi    %1, #1\n"
 320                 "       bnez    %0, strnlen_byte_loop\n"
 321                 "strnlen_exit:\n"
 322                 "       sub     %1, r1\n"
 323                 "       add3    %0, %1, #1\n"
 324                 "       .fillinsn\n"
 325                 "9:\n"
 326                 ".section .fixup,\"ax\"\n"
 327                 "       .balign 4\n"
 328                 "4:     addi    %1, #-4\n"
 329                 "       .fillinsn\n"
 330                 "5:     ldi     %0, #0\n"
 331                 "       seth    r1, #high(9b)\n"
 332                 "       or3     r1, r1, #low(9b)\n"
 333                 "       jmp     r1\n"
 334                 ".previous\n"
 335                 ".section __ex_table,\"a\"\n"
 336                 "       .balign 4\n"
 337                 "       .long 0b,4b\n"
 338                 "       .long 1b,5b\n"
 339                 ".previous"
 340                 : "=&r" (res), "=r" (s)
 341                 : "0" (n), "1" (s), "r" (n & 3), "r" (mask), "r"(0x01010101)
 342                 : "r0", "r1", "r2", "r3", "cbit");
 343
 344         /* NOTE: strnlen_user() algorithm:
 345          * {
 346          *   char *p;
 347          *   for (p = s; n-- && *p != '\0'; ++p)
 348          *     ;
 349          *   return p - s + 1;
 350          * }
 351          */
 352
 353         /* NOTE: If a null char. exists, return 0.
 354          * if ((x - 0x01010101) & ~x & 0x80808080)\n"
 355          *   return 0;\n"
 356          */
 357
 358         return res & mask;
 359 }
 360
 361 #endif /* CONFIG_ISA_DUAL_ISSUE */
 362