git.oblomov.eu Git - linux-2.6/blob - arch/m32r/lib/usercopy.c

   1 /*
   2  * User address space access functions.
   3  * The non inlined parts of asm-m32r/uaccess.h are here.
   4  *
   5  * Copyright 1997 Andi Kleen <ak@muc.de>
   6  * Copyright 1997 Linus Torvalds
   7  * Copyright 2001, 2002, 2004 Hirokazu Takata
   8  */
   9 #include <linux/prefetch.h>
  10 #include <linux/string.h>
  11 #include <linux/thread_info.h>
  12 #include <asm/uaccess.h>
  13
  14 unsigned long
  15 __generic_copy_to_user(void __user *to, const void *from, unsigned long n)
  16 {
  17         prefetch(from);
  18         if (access_ok(VERIFY_WRITE, to, n))
  19                 __copy_user(to,from,n);
  20         return n;
  21 }
  22
  23 unsigned long
  24 __generic_copy_from_user(void *to, const void __user *from, unsigned long n)
  25 {
  26         prefetchw(to);
  27         if (access_ok(VERIFY_READ, from, n))
  28                 __copy_user_zeroing(to,from,n);
  29         else
  30                 memset(to, 0, n);
  31         return n;
  32 }
  33
  34
  35 /*
  36  * Copy a null terminated string from userspace.
  37  */
  38
  39 #ifdef CONFIG_ISA_DUAL_ISSUE
  40
  41 #define __do_strncpy_from_user(dst,src,count,res)                       \
  42 do {                                                                    \
  43         int __d0, __d1, __d2;                                           \
  44         __asm__ __volatile__(                                           \
  45                 "       beqz    %1, 2f\n"                               \
  46                 "       .fillinsn\n"                                    \
  47                 "0:     ldb     r14, @%3    ||  addi    %3, #1\n"       \
  48                 "       stb     r14, @%4    ||  addi    %4, #1\n"       \
  49                 "       beqz    r14, 1f\n"                              \
  50                 "       addi    %1, #-1\n"                              \
  51                 "       bnez    %1, 0b\n"                               \
  52                 "       .fillinsn\n"                                    \
  53                 "1:     sub     %0, %1\n"                               \
  54                 "       .fillinsn\n"                                    \
  55                 "2:\n"                                                  \
  56                 ".section .fixup,\"ax\"\n"                              \
  57                 "       .balign 4\n"                                    \
  58                 "3:     seth    r14, #high(2b)\n"                       \
  59                 "       or3     r14, r14, #low(2b)\n"                   \
  60                 "       jmp     r14         ||  ldi     %0, #%5\n"      \
  61                 ".previous\n"                                           \
  62                 ".section __ex_table,\"a\"\n"                           \
  63                 "       .balign 4\n"                                    \
  64                 "       .long 0b,3b\n"                                  \
  65                 ".previous"                                             \
  66                 : "=&r"(res), "=&r"(count), "=&r" (__d0), "=&r" (__d1), \
  67                   "=&r" (__d2)                                          \
  68                 : "i"(-EFAULT), "0"(count), "1"(count), "3"(src),       \
  69                   "4"(dst)                                              \
  70                 : "r14", "cbit", "memory");                             \
  71 } while (0)
  72
  73 #else /* not CONFIG_ISA_DUAL_ISSUE */
  74
  75 #define __do_strncpy_from_user(dst,src,count,res)                       \
  76 do {                                                                    \
  77         int __d0, __d1, __d2;                                           \
  78         __asm__ __volatile__(                                           \
  79                 "       beqz    %1, 2f\n"                               \
  80                 "       .fillinsn\n"                                    \
  81                 "0:     ldb     r14, @%3\n"                             \
  82                 "       stb     r14, @%4\n"                             \
  83                 "       addi    %3, #1\n"                               \
  84                 "       addi    %4, #1\n"                               \
  85                 "       beqz    r14, 1f\n"                              \
  86                 "       addi    %1, #-1\n"                              \
  87                 "       bnez    %1, 0b\n"                               \
  88                 "       .fillinsn\n"                                    \
  89                 "1:     sub     %0, %1\n"                               \
  90                 "       .fillinsn\n"                                    \
  91                 "2:\n"                                                  \
  92                 ".section .fixup,\"ax\"\n"                              \
  93                 "       .balign 4\n"                                    \
  94                 "3:     ldi     %0, #%5\n"                              \
  95                 "       seth    r14, #high(2b)\n"                       \
  96                 "       or3     r14, r14, #low(2b)\n"                   \
  97                 "       jmp     r14\n"                                  \
  98                 ".previous\n"                                           \
  99                 ".section __ex_table,\"a\"\n"                           \
 100                 "       .balign 4\n"                                    \
 101                 "       .long 0b,3b\n"                                  \
 102                 ".previous"                                             \
 103                 : "=&r"(res), "=&r"(count), "=&r" (__d0), "=&r" (__d1), \
 104                   "=&r" (__d2)                                          \
 105                 : "i"(-EFAULT), "0"(count), "1"(count), "3"(src),       \
 106                   "4"(dst)                                              \
 107                 : "r14", "cbit", "memory");                             \
 108 } while (0)
 109
 110 #endif /* CONFIG_ISA_DUAL_ISSUE */
 111
 112 long
 113 __strncpy_from_user(char *dst, const char __user *src, long count)
 114 {
 115         long res;
 116         __do_strncpy_from_user(dst, src, count, res);
 117         return res;
 118 }
 119
 120 long
 121 strncpy_from_user(char *dst, const char __user *src, long count)
 122 {
 123         long res = -EFAULT;
 124         if (access_ok(VERIFY_READ, src, 1))
 125                 __do_strncpy_from_user(dst, src, count, res);
 126         return res;
 127 }
 128
 129
 130 /*
 131  * Zero Userspace
 132  */
 133
 134 #ifdef CONFIG_ISA_DUAL_ISSUE
 135
 136 #define __do_clear_user(addr,size)                                      \
 137 do {                                                                    \
 138         int __dst, __c;                                                 \
 139         __asm__ __volatile__(                                           \
 140                 "       beqz    %1, 9f\n"                               \
 141                 "       and3    r14, %0, #3\n"                          \
 142                 "       bnez    r14, 2f\n"                              \
 143                 "       and3    r14, %1, #3\n"                          \
 144                 "       bnez    r14, 2f\n"                              \
 145                 "       and3    %1, %1, #3\n"                           \
 146                 "       beqz    %2, 2f\n"                               \
 147                 "       addi    %0, #-4\n"                              \
 148                 "       .fillinsn\n"                                    \
 149                 "0:     ; word clear \n"                                \
 150                 "       st      %6, @+%0    ||  addi    %2, #-1\n"      \
 151                 "       bnez    %2, 0b\n"                               \
 152                 "       beqz    %1, 9f\n"                               \
 153                 "       .fillinsn\n"                                    \
 154                 "2:     ; byte clear \n"                                \
 155                 "       stb     %6, @%0     ||  addi    %1, #-1\n"      \
 156                 "       addi    %0, #1\n"                               \
 157                 "       bnez    %1, 2b\n"                               \
 158                 "       .fillinsn\n"                                    \
 159                 "9:\n"                                                  \
 160                 ".section .fixup,\"ax\"\n"                              \
 161                 "       .balign 4\n"                                    \
 162                 "4:     slli    %2, #2\n"                               \
 163                 "       seth    r14, #high(9b)\n"                       \
 164                 "       or3     r14, r14, #low(9b)\n"                   \
 165                 "       jmp     r14         ||  add     %1, %2\n"       \
 166                 ".previous\n"                                           \
 167                 ".section __ex_table,\"a\"\n"                           \
 168                 "       .balign 4\n"                                    \
 169                 "       .long 0b,4b\n"                                  \
 170                 "       .long 2b,9b\n"                                  \
 171                 ".previous\n"                                           \
 172                 : "=&r"(__dst), "=&r"(size), "=&r"(__c)                 \
 173                 : "0"(addr), "1"(size), "2"(size / 4), "r"(0)           \
 174                 : "r14", "cbit", "memory");                             \
 175 } while (0)
 176
 177 #else /* not CONFIG_ISA_DUAL_ISSUE */
 178
 179 #define __do_clear_user(addr,size)                                      \
 180 do {                                                                    \
 181         int __dst, __c;                                                 \
 182         __asm__ __volatile__(                                           \
 183                 "       beqz    %1, 9f\n"                               \
 184                 "       and3    r14, %0, #3\n"                          \
 185                 "       bnez    r14, 2f\n"                              \
 186                 "       and3    r14, %1, #3\n"                          \
 187                 "       bnez    r14, 2f\n"                              \
 188                 "       and3    %1, %1, #3\n"                           \
 189                 "       beqz    %2, 2f\n"                               \
 190                 "       addi    %0, #-4\n"                              \
 191                 "       .fillinsn\n"                                    \
 192                 "0:     st      %6, @+%0        ; word clear \n"        \
 193                 "       addi    %2, #-1\n"                              \
 194                 "       bnez    %2, 0b\n"                               \
 195                 "       beqz    %1, 9f\n"                               \
 196                 "       .fillinsn\n"                                    \
 197                 "2:     stb     %6, @%0         ; byte clear \n"        \
 198                 "       addi    %1, #-1\n"                              \
 199                 "       addi    %0, #1\n"                               \
 200                 "       bnez    %1, 2b\n"                               \
 201                 "       .fillinsn\n"                                    \
 202                 "9:\n"                                                  \
 203                 ".section .fixup,\"ax\"\n"                              \
 204                 "       .balign 4\n"                                    \
 205                 "4:     slli    %2, #2\n"                               \
 206                 "       add     %1, %2\n"                               \
 207                 "       seth    r14, #high(9b)\n"                       \
 208                 "       or3     r14, r14, #low(9b)\n"                   \
 209                 "       jmp     r14\n"                                  \
 210                 ".previous\n"                                           \
 211                 ".section __ex_table,\"a\"\n"                           \
 212                 "       .balign 4\n"                                    \
 213                 "       .long 0b,4b\n"                                  \
 214                 "       .long 2b,9b\n"                                  \
 215                 ".previous\n"                                           \
 216                 : "=&r"(__dst), "=&r"(size), "=&r"(__c)                 \
 217                 : "0"(addr), "1"(size), "2"(size / 4), "r"(0)           \
 218                 : "r14", "cbit", "memory");                             \
 219 } while (0)
 220
 221 #endif /* not CONFIG_ISA_DUAL_ISSUE */
 222
 223 unsigned long
 224 clear_user(void __user *to, unsigned long n)
 225 {
 226         if (access_ok(VERIFY_WRITE, to, n))
 227                 __do_clear_user(to, n);
 228         return n;
 229 }
 230
 231 unsigned long
 232 __clear_user(void __user *to, unsigned long n)
 233 {
 234         __do_clear_user(to, n);
 235         return n;
 236 }
 237
 238 /*
 239  * Return the size of a string (including the ending 0)
 240  *
 241  * Return 0 on exception, a value greater than N if too long
 242  */
 243
 244 #ifdef CONFIG_ISA_DUAL_ISSUE
 245
 246 long strnlen_user(const char __user *s, long n)
 247 {
 248         unsigned long mask = -__addr_ok(s);
 249         unsigned long res;
 250
 251         __asm__ __volatile__(
 252                 "       and     %0, %5      ||  mv      r1, %1\n"
 253                 "       beqz    %0, strnlen_exit\n"
 254                 "       and3    r0, %1, #3\n"
 255                 "       bnez    r0, strnlen_byte_loop\n"
 256                 "       cmpui   %0, #4\n"
 257                 "       bc      strnlen_byte_loop\n"
 258                 "strnlen_word_loop:\n"
 259                 "0:     ld      r0, @%1+\n"
 260                 "       pcmpbz  r0\n"
 261                 "       bc      strnlen_last_bytes_fixup\n"
 262                 "       addi    %0, #-4\n"
 263                 "       beqz    %0, strnlen_exit\n"
 264                 "       bgtz    %0, strnlen_word_loop\n"
 265                 "strnlen_last_bytes:\n"
 266                 "       mv      %0, %4\n"
 267                 "strnlen_last_bytes_fixup:\n"
 268                 "       addi    %1, #-4\n"
 269                 "strnlen_byte_loop:\n"
 270                 "1:     ldb     r0, @%1     ||  addi    %0, #-1\n"
 271                 "       beqz    r0, strnlen_exit\n"
 272                 "       addi    %1, #1\n"
 273                 "       bnez    %0, strnlen_byte_loop\n"
 274                 "strnlen_exit:\n"
 275                 "       sub     %1, r1\n"
 276                 "       add3    %0, %1, #1\n"
 277                 "       .fillinsn\n"
 278                 "9:\n"
 279                 ".section .fixup,\"ax\"\n"
 280                 "       .balign 4\n"
 281                 "4:     addi    %1, #-4\n"
 282                 "       .fillinsn\n"
 283                 "5:     seth    r1, #high(9b)\n"
 284                 "       or3     r1, r1, #low(9b)\n"
 285                 "       jmp     r1          ||  ldi     %0, #0\n"
 286                 ".previous\n"
 287                 ".section __ex_table,\"a\"\n"
 288                 "       .balign 4\n"
 289                 "       .long 0b,4b\n"
 290                 "       .long 1b,5b\n"
 291                 ".previous"
 292                 : "=&r" (res), "=r" (s)
 293                 : "0" (n), "1" (s), "r" (n & 3), "r" (mask), "r"(0x01010101)
 294                 : "r0", "r1", "cbit");
 295
 296         /* NOTE: strnlen_user() algorithm:
 297          * {
 298          *   char *p;
 299          *   for (p = s; n-- && *p != '\0'; ++p)
 300          *     ;
 301          *   return p - s + 1;
 302          * }
 303          */
 304
 305         /* NOTE: If a null char. exists, return 0.
 306          * if ((x - 0x01010101) & ~x & 0x80808080)\n"
 307          *   return 0;\n"
 308          */
 309
 310         return res & mask;
 311 }
 312
 313 #else /* not CONFIG_ISA_DUAL_ISSUE */
 314
 315 long strnlen_user(const char __user *s, long n)
 316 {
 317         unsigned long mask = -__addr_ok(s);
 318         unsigned long res;
 319
 320         __asm__ __volatile__(
 321                 "       and     %0, %5\n"
 322                 "       mv      r1, %1\n"
 323                 "       beqz    %0, strnlen_exit\n"
 324                 "       and3    r0, %1, #3\n"
 325                 "       bnez    r0, strnlen_byte_loop\n"
 326                 "       cmpui   %0, #4\n"
 327                 "       bc      strnlen_byte_loop\n"
 328                 "       sll3    r3, %6, #7\n"
 329                 "strnlen_word_loop:\n"
 330                 "0:     ld      r0, @%1+\n"
 331                 "       not     r2, r0\n"
 332                 "       sub     r0, %6\n"
 333                 "       and     r2, r3\n"
 334                 "       and     r2, r0\n"
 335                 "       bnez    r2, strnlen_last_bytes_fixup\n"
 336                 "       addi    %0, #-4\n"
 337                 "       beqz    %0, strnlen_exit\n"
 338                 "       bgtz    %0, strnlen_word_loop\n"
 339                 "strnlen_last_bytes:\n"
 340                 "       mv      %0, %4\n"
 341                 "strnlen_last_bytes_fixup:\n"
 342                 "       addi    %1, #-4\n"
 343                 "strnlen_byte_loop:\n"
 344                 "1:     ldb     r0, @%1\n"
 345                 "       addi    %0, #-1\n"
 346                 "       beqz    r0, strnlen_exit\n"
 347                 "       addi    %1, #1\n"
 348                 "       bnez    %0, strnlen_byte_loop\n"
 349                 "strnlen_exit:\n"
 350                 "       sub     %1, r1\n"
 351                 "       add3    %0, %1, #1\n"
 352                 "       .fillinsn\n"
 353                 "9:\n"
 354                 ".section .fixup,\"ax\"\n"
 355                 "       .balign 4\n"
 356                 "4:     addi    %1, #-4\n"
 357                 "       .fillinsn\n"
 358                 "5:     ldi     %0, #0\n"
 359                 "       seth    r1, #high(9b)\n"
 360                 "       or3     r1, r1, #low(9b)\n"
 361                 "       jmp     r1\n"
 362                 ".previous\n"
 363                 ".section __ex_table,\"a\"\n"
 364                 "       .balign 4\n"
 365                 "       .long 0b,4b\n"
 366                 "       .long 1b,5b\n"
 367                 ".previous"
 368                 : "=&r" (res), "=r" (s)
 369                 : "0" (n), "1" (s), "r" (n & 3), "r" (mask), "r"(0x01010101)
 370                 : "r0", "r1", "r2", "r3", "cbit");
 371
 372         /* NOTE: strnlen_user() algorithm:
 373          * {
 374          *   char *p;
 375          *   for (p = s; n-- && *p != '\0'; ++p)
 376          *     ;
 377          *   return p - s + 1;
 378          * }
 379          */
 380
 381         /* NOTE: If a null char. exists, return 0.
 382          * if ((x - 0x01010101) & ~x & 0x80808080)\n"
 383          *   return 0;\n"
 384          */
 385
 386         return res & mask;
 387 }
 388
 389 #endif /* CONFIG_ISA_DUAL_ISSUE */
 390