arch/i386/lib/usercopy.c

   1 /*
   2  * User address space access functions.
   3  * The non inlined parts of asm-i386/uaccess.h are here.
   4  *
   5  * Copyright 1997 Andi Kleen <ak@muc.de>
   6  * Copyright 1997 Linus Torvalds
   7  */
   8 #include <linux/mm.h>
   9 #include <linux/highmem.h>
  10 #include <linux/blkdev.h>
  11 #include <linux/module.h>
  12 #include <asm/uaccess.h>
  13 #include <asm/mmx.h>
  14
  15 static inline int __movsl_is_ok(unsigned long a1, unsigned long a2, unsigned long n)
  16 {
  17 #ifdef CONFIG_X86_INTEL_USERCOPY
  18         if (n >= 64 && ((a1 ^ a2) & movsl_mask.mask))
  19                 return 0;
  20 #endif
  21         return 1;
  22 }
  23 #define movsl_is_ok(a1,a2,n) \
  24         __movsl_is_ok((unsigned long)(a1),(unsigned long)(a2),(n))
  25
  26 /*
  27  * Copy a null terminated string from userspace.
  28  */
  29
  30 #define __do_strncpy_from_user(dst,src,count,res)                          \
  31 do {                                                                       \
  32         int __d0, __d1, __d2;                                              \
  33         might_sleep();                                                     \
  34         __asm__ __volatile__(                                              \
  35                 "       testl %1,%1\n"                                     \
  36                 "       jz 2f\n"                                           \
  37                 "0:     lodsb\n"                                           \
  38                 "       stosb\n"                                           \
  39                 "       testb %%al,%%al\n"                                 \
  40                 "       jz 1f\n"                                           \
  41                 "       decl %1\n"                                         \
  42                 "       jnz 0b\n"                                          \
  43                 "1:     subl %1,%0\n"                                      \
  44                 "2:\n"                                                     \
  45                 ".section .fixup,\"ax\"\n"                                 \
  46                 "3:     movl %5,%0\n"                                      \
  47                 "       jmp 2b\n"                                          \
  48                 ".previous\n"                                              \
  49                 ".section __ex_table,\"a\"\n"                              \
  50                 "       .align 4\n"                                        \
  51                 "       .long 0b,3b\n"                                     \
  52                 ".previous"                                                \
  53                 : "=d"(res), "=c"(count), "=&a" (__d0), "=&S" (__d1),      \
  54                   "=&D" (__d2)                                             \
  55                 : "i"(-EFAULT), "0"(count), "1"(count), "3"(src), "4"(dst) \
  56                 : "memory");                                               \
  57 } while (0)
  58
  59 /**
  60  * __strncpy_from_user: - Copy a NUL terminated string from userspace, with less checking.
  61  * @dst:   Destination address, in kernel space.  This buffer must be at
  62  *         least @count bytes long.
  63  * @src:   Source address, in user space.
  64  * @count: Maximum number of bytes to copy, including the trailing NUL.
  65  *
  66  * Copies a NUL-terminated string from userspace to kernel space.
  67  * Caller must check the specified block with access_ok() before calling
  68  * this function.
  69  *
  70  * On success, returns the length of the string (not including the trailing
  71  * NUL).
  72  *
  73  * If access to userspace fails, returns -EFAULT (some data may have been
  74  * copied).
  75  *
  76  * If @count is smaller than the length of the string, copies @count bytes
  77  * and returns @count.
  78  */
  79 long
  80 __strncpy_from_user(char *dst, const char __user *src, long count)
  81 {
  82         long res;
  83         __do_strncpy_from_user(dst, src, count, res);
  84         return res;
  85 }
  86 EXPORT_SYMBOL(__strncpy_from_user);
  87
  88 /**
  89  * strncpy_from_user: - Copy a NUL terminated string from userspace.
  90  * @dst:   Destination address, in kernel space.  This buffer must be at
  91  *         least @count bytes long.
  92  * @src:   Source address, in user space.
  93  * @count: Maximum number of bytes to copy, including the trailing NUL.
  94  *
  95  * Copies a NUL-terminated string from userspace to kernel space.
  96  *
  97  * On success, returns the length of the string (not including the trailing
  98  * NUL).
  99  *
 100  * If access to userspace fails, returns -EFAULT (some data may have been
 101  * copied).
 102  *
 103  * If @count is smaller than the length of the string, copies @count bytes
 104  * and returns @count.
 105  */
 106 long
 107 strncpy_from_user(char *dst, const char __user *src, long count)
 108 {
 109         long res = -EFAULT;
 110         if (access_ok(VERIFY_READ, src, 1))
 111                 __do_strncpy_from_user(dst, src, count, res);
 112         return res;
 113 }
 114 EXPORT_SYMBOL(strncpy_from_user);
 115
 116 /*
 117  * Zero Userspace
 118  */
 119
 120 #define __do_clear_user(addr,size)                                      \
 121 do {                                                                    \
 122         int __d0;                                                       \
 123         might_sleep();                                                  \
 124         __asm__ __volatile__(                                           \
 125                 "0:     rep; stosl\n"                                   \
 126                 "       movl %2,%0\n"                                   \
 127                 "1:     rep; stosb\n"                                   \
 128                 "2:\n"                                                  \
 129                 ".section .fixup,\"ax\"\n"                              \
 130                 "3:     lea 0(%2,%0,4),%0\n"                            \
 131                 "       jmp 2b\n"                                       \
 132                 ".previous\n"                                           \
 133                 ".section __ex_table,\"a\"\n"                           \
 134                 "       .align 4\n"                                     \
 135                 "       .long 0b,3b\n"                                  \
 136                 "       .long 1b,2b\n"                                  \
 137                 ".previous"                                             \
 138                 : "=&c"(size), "=&D" (__d0)                             \
 139                 : "r"(size & 3), "0"(size / 4), "1"(addr), "a"(0));     \
 140 } while (0)
 141
 142 /**
 143  * clear_user: - Zero a block of memory in user space.
 144  * @to:   Destination address, in user space.
 145  * @n:    Number of bytes to zero.
 146  *
 147  * Zero a block of memory in user space.
 148  *
 149  * Returns number of bytes that could not be cleared.
 150  * On success, this will be zero.
 151  */
 152 unsigned long
 153 clear_user(void __user *to, unsigned long n)
 154 {
 155         might_sleep();
 156         if (access_ok(VERIFY_WRITE, to, n))
 157                 __do_clear_user(to, n);
 158         return n;
 159 }
 160 EXPORT_SYMBOL(clear_user);
 161
 162 /**
 163  * __clear_user: - Zero a block of memory in user space, with less checking.
 164  * @to:   Destination address, in user space.
 165  * @n:    Number of bytes to zero.
 166  *
 167  * Zero a block of memory in user space.  Caller must check
 168  * the specified block with access_ok() before calling this function.
 169  *
 170  * Returns number of bytes that could not be cleared.
 171  * On success, this will be zero.
 172  */
 173 unsigned long
 174 __clear_user(void __user *to, unsigned long n)
 175 {
 176         __do_clear_user(to, n);
 177         return n;
 178 }
 179 EXPORT_SYMBOL(__clear_user);
 180
 181 /**
 182  * strlen_user: - Get the size of a string in user space.
 183  * @s: The string to measure.
 184  * @n: The maximum valid length
 185  *
 186  * Get the size of a NUL-terminated string in user space.
 187  *
 188  * Returns the size of the string INCLUDING the terminating NUL.
 189  * On exception, returns 0.
 190  * If the string is too long, returns a value greater than @n.
 191  */
 192 long strnlen_user(const char __user *s, long n)
 193 {
 194         unsigned long mask = -__addr_ok(s);
 195         unsigned long res, tmp;
 196
 197         might_sleep();
 198
 199         __asm__ __volatile__(
 200                 "       testl %0, %0\n"
 201                 "       jz 3f\n"
 202                 "       andl %0,%%ecx\n"
 203                 "0:     repne; scasb\n"
 204                 "       setne %%al\n"
 205                 "       subl %%ecx,%0\n"
 206                 "       addl %0,%%eax\n"
 207                 "1:\n"
 208                 ".section .fixup,\"ax\"\n"
 209                 "2:     xorl %%eax,%%eax\n"
 210                 "       jmp 1b\n"
 211                 "3:     movb $1,%%al\n"
 212                 "       jmp 1b\n"
 213                 ".previous\n"
 214                 ".section __ex_table,\"a\"\n"
 215                 "       .align 4\n"
 216                 "       .long 0b,2b\n"
 217                 ".previous"
 218                 :"=r" (n), "=D" (s), "=a" (res), "=c" (tmp)
 219                 :"0" (n), "1" (s), "2" (0), "3" (mask)
 220                 :"cc");
 221         return res & mask;
 222 }
 223 EXPORT_SYMBOL(strnlen_user);
 224
 225 #ifdef CONFIG_X86_INTEL_USERCOPY
 226 static unsigned long
 227 __copy_user_intel(void __user *to, const void *from, unsigned long size)
 228 {
 229         int d0, d1;
 230         __asm__ __volatile__(
 231                        "       .align 2,0x90\n"
 232                        "1:     movl 32(%4), %%eax\n"
 233                        "       cmpl $67, %0\n"
 234                        "       jbe 3f\n"
 235                        "2:     movl 64(%4), %%eax\n"
 236                        "       .align 2,0x90\n"
 237                        "3:     movl 0(%4), %%eax\n"
 238                        "4:     movl 4(%4), %%edx\n"
 239                        "5:     movl %%eax, 0(%3)\n"
 240                        "6:     movl %%edx, 4(%3)\n"
 241                        "7:     movl 8(%4), %%eax\n"
 242                        "8:     movl 12(%4),%%edx\n"
 243                        "9:     movl %%eax, 8(%3)\n"
 244                        "10:    movl %%edx, 12(%3)\n"
 245                        "11:    movl 16(%4), %%eax\n"
 246                        "12:    movl 20(%4), %%edx\n"
 247                        "13:    movl %%eax, 16(%3)\n"
 248                        "14:    movl %%edx, 20(%3)\n"
 249                        "15:    movl 24(%4), %%eax\n"
 250                        "16:    movl 28(%4), %%edx\n"
 251                        "17:    movl %%eax, 24(%3)\n"
 252                        "18:    movl %%edx, 28(%3)\n"
 253                        "19:    movl 32(%4), %%eax\n"
 254                        "20:    movl 36(%4), %%edx\n"
 255                        "21:    movl %%eax, 32(%3)\n"
 256                        "22:    movl %%edx, 36(%3)\n"
 257                        "23:    movl 40(%4), %%eax\n"
 258                        "24:    movl 44(%4), %%edx\n"
 259                        "25:    movl %%eax, 40(%3)\n"
 260                        "26:    movl %%edx, 44(%3)\n"
 261                        "27:    movl 48(%4), %%eax\n"
 262                        "28:    movl 52(%4), %%edx\n"
 263                        "29:    movl %%eax, 48(%3)\n"
 264                        "30:    movl %%edx, 52(%3)\n"
 265                        "31:    movl 56(%4), %%eax\n"
 266                        "32:    movl 60(%4), %%edx\n"
 267                        "33:    movl %%eax, 56(%3)\n"
 268                        "34:    movl %%edx, 60(%3)\n"
 269                        "       addl $-64, %0\n"
 270                        "       addl $64, %4\n"
 271                        "       addl $64, %3\n"
 272                        "       cmpl $63, %0\n"
 273                        "       ja  1b\n"
 274                        "35:    movl  %0, %%eax\n"
 275                        "       shrl  $2, %0\n"
 276                        "       andl  $3, %%eax\n"
 277                        "       cld\n"
 278                        "99:    rep; movsl\n"
 279                        "36:    movl %%eax, %0\n"
 280                        "37:    rep; movsb\n"
 281                        "100:\n"
 282                        ".section .fixup,\"ax\"\n"
 283                        "101:   lea 0(%%eax,%0,4),%0\n"
 284                        "       jmp 100b\n"
 285                        ".previous\n"
 286                        ".section __ex_table,\"a\"\n"
 287                        "       .align 4\n"
 288                        "       .long 1b,100b\n"
 289                        "       .long 2b,100b\n"
 290                        "       .long 3b,100b\n"
 291                        "       .long 4b,100b\n"
 292                        "       .long 5b,100b\n"
 293                        "       .long 6b,100b\n"
 294                        "       .long 7b,100b\n"
 295                        "       .long 8b,100b\n"
 296                        "       .long 9b,100b\n"
 297                        "       .long 10b,100b\n"
 298                        "       .long 11b,100b\n"
 299                        "       .long 12b,100b\n"
 300                        "       .long 13b,100b\n"
 301                        "       .long 14b,100b\n"
 302                        "       .long 15b,100b\n"
 303                        "       .long 16b,100b\n"
 304                        "       .long 17b,100b\n"
 305                        "       .long 18b,100b\n"
 306                        "       .long 19b,100b\n"
 307                        "       .long 20b,100b\n"
 308                        "       .long 21b,100b\n"
 309                        "       .long 22b,100b\n"
 310                        "       .long 23b,100b\n"
 311                        "       .long 24b,100b\n"
 312                        "       .long 25b,100b\n"
 313                        "       .long 26b,100b\n"
 314                        "       .long 27b,100b\n"
 315                        "       .long 28b,100b\n"
 316                        "       .long 29b,100b\n"
 317                        "       .long 30b,100b\n"
 318                        "       .long 31b,100b\n"
 319                        "       .long 32b,100b\n"
 320                        "       .long 33b,100b\n"
 321                        "       .long 34b,100b\n"
 322                        "       .long 35b,100b\n"
 323                        "       .long 36b,100b\n"
 324                        "       .long 37b,100b\n"
 325                        "       .long 99b,101b\n"
 326                        ".previous"
 327                        : "=&c"(size), "=&D" (d0), "=&S" (d1)
 328                        :  "1"(to), "2"(from), "0"(size)
 329                        : "eax", "edx", "memory");
 330         return size;
 331 }
 332
 333 static unsigned long
 334 __copy_user_zeroing_intel(void *to, const void __user *from, unsigned long size)
 335 {
 336         int d0, d1;
 337         __asm__ __volatile__(
 338                        "        .align 2,0x90\n"
 339                        "0:      movl 32(%4), %%eax\n"
 340                        "        cmpl $67, %0\n"
 341                        "        jbe 2f\n"
 342                        "1:      movl 64(%4), %%eax\n"
 343                        "        .align 2,0x90\n"
 344                        "2:      movl 0(%4), %%eax\n"
 345                        "21:     movl 4(%4), %%edx\n"
 346                        "        movl %%eax, 0(%3)\n"
 347                        "        movl %%edx, 4(%3)\n"
 348                        "3:      movl 8(%4), %%eax\n"
 349                        "31:     movl 12(%4),%%edx\n"
 350                        "        movl %%eax, 8(%3)\n"
 351                        "        movl %%edx, 12(%3)\n"
 352                        "4:      movl 16(%4), %%eax\n"
 353                        "41:     movl 20(%4), %%edx\n"
 354                        "        movl %%eax, 16(%3)\n"
 355                        "        movl %%edx, 20(%3)\n"
 356                        "10:     movl 24(%4), %%eax\n"
 357                        "51:     movl 28(%4), %%edx\n"
 358                        "        movl %%eax, 24(%3)\n"
 359                        "        movl %%edx, 28(%3)\n"
 360                        "11:     movl 32(%4), %%eax\n"
 361                        "61:     movl 36(%4), %%edx\n"
 362                        "        movl %%eax, 32(%3)\n"
 363                        "        movl %%edx, 36(%3)\n"
 364                        "12:     movl 40(%4), %%eax\n"
 365                        "71:     movl 44(%4), %%edx\n"
 366                        "        movl %%eax, 40(%3)\n"
 367                        "        movl %%edx, 44(%3)\n"
 368                        "13:     movl 48(%4), %%eax\n"
 369                        "81:     movl 52(%4), %%edx\n"
 370                        "        movl %%eax, 48(%3)\n"
 371                        "        movl %%edx, 52(%3)\n"
 372                        "14:     movl 56(%4), %%eax\n"
 373                        "91:     movl 60(%4), %%edx\n"
 374                        "        movl %%eax, 56(%3)\n"
 375                        "        movl %%edx, 60(%3)\n"
 376                        "        addl $-64, %0\n"
 377                        "        addl $64, %4\n"
 378                        "        addl $64, %3\n"
 379                        "        cmpl $63, %0\n"
 380                        "        ja  0b\n"
 381                        "5:      movl  %0, %%eax\n"
 382                        "        shrl  $2, %0\n"
 383                        "        andl $3, %%eax\n"
 384                        "        cld\n"
 385                        "6:      rep; movsl\n"
 386                        "        movl %%eax,%0\n"
 387                        "7:      rep; movsb\n"
 388                        "8:\n"
 389                        ".section .fixup,\"ax\"\n"
 390                        "9:      lea 0(%%eax,%0,4),%0\n"
 391                        "16:     pushl %0\n"
 392                        "        pushl %%eax\n"
 393                        "        xorl %%eax,%%eax\n"
 394                        "        rep; stosb\n"
 395                        "        popl %%eax\n"
 396                        "        popl %0\n"
 397                        "        jmp 8b\n"
 398                        ".previous\n"
 399                        ".section __ex_table,\"a\"\n"
 400                        "        .align 4\n"
 401                        "        .long 0b,16b\n"
 402                        "        .long 1b,16b\n"
 403                        "        .long 2b,16b\n"
 404                        "        .long 21b,16b\n"
 405                        "        .long 3b,16b\n"
 406                        "        .long 31b,16b\n"
 407                        "        .long 4b,16b\n"
 408                        "        .long 41b,16b\n"
 409                        "        .long 10b,16b\n"
 410                        "        .long 51b,16b\n"
 411                        "        .long 11b,16b\n"
 412                        "        .long 61b,16b\n"
 413                        "        .long 12b,16b\n"
 414                        "        .long 71b,16b\n"
 415                        "        .long 13b,16b\n"
 416                        "        .long 81b,16b\n"
 417                        "        .long 14b,16b\n"
 418                        "        .long 91b,16b\n"
 419                        "        .long 6b,9b\n"
 420                        "        .long 7b,16b\n"
 421                        ".previous"
 422                        : "=&c"(size), "=&D" (d0), "=&S" (d1)
 423                        :  "1"(to), "2"(from), "0"(size)
 424                        : "eax", "edx", "memory");
 425         return size;
 426 }
 427
 428 /*
 429  * Non Temporal Hint version of __copy_user_zeroing_intel.  It is cache aware.
 430  * hyoshiok@miraclelinux.com
 431  */
 432
 433 static unsigned long __copy_user_zeroing_intel_nocache(void *to,
 434                                 const void __user *from, unsigned long size)
 435 {
 436         int d0, d1;
 437
 438         __asm__ __volatile__(
 439                "        .align 2,0x90\n"
 440                "0:      movl 32(%4), %%eax\n"
 441                "        cmpl $67, %0\n"
 442                "        jbe 2f\n"
 443                "1:      movl 64(%4), %%eax\n"
 444                "        .align 2,0x90\n"
 445                "2:      movl 0(%4), %%eax\n"
 446                "21:     movl 4(%4), %%edx\n"
 447                "        movnti %%eax, 0(%3)\n"
 448                "        movnti %%edx, 4(%3)\n"
 449                "3:      movl 8(%4), %%eax\n"
 450                "31:     movl 12(%4),%%edx\n"
 451                "        movnti %%eax, 8(%3)\n"
 452                "        movnti %%edx, 12(%3)\n"
 453                "4:      movl 16(%4), %%eax\n"
 454                "41:     movl 20(%4), %%edx\n"
 455                "        movnti %%eax, 16(%3)\n"
 456                "        movnti %%edx, 20(%3)\n"
 457                "10:     movl 24(%4), %%eax\n"
 458                "51:     movl 28(%4), %%edx\n"
 459                "        movnti %%eax, 24(%3)\n"
 460                "        movnti %%edx, 28(%3)\n"
 461                "11:     movl 32(%4), %%eax\n"
 462                "61:     movl 36(%4), %%edx\n"
 463                "        movnti %%eax, 32(%3)\n"
 464                "        movnti %%edx, 36(%3)\n"
 465                "12:     movl 40(%4), %%eax\n"
 466                "71:     movl 44(%4), %%edx\n"
 467                "        movnti %%eax, 40(%3)\n"
 468                "        movnti %%edx, 44(%3)\n"
 469                "13:     movl 48(%4), %%eax\n"
 470                "81:     movl 52(%4), %%edx\n"
 471                "        movnti %%eax, 48(%3)\n"
 472                "        movnti %%edx, 52(%3)\n"
 473                "14:     movl 56(%4), %%eax\n"
 474                "91:     movl 60(%4), %%edx\n"
 475                "        movnti %%eax, 56(%3)\n"
 476                "        movnti %%edx, 60(%3)\n"
 477                "        addl $-64, %0\n"
 478                "        addl $64, %4\n"
 479                "        addl $64, %3\n"
 480                "        cmpl $63, %0\n"
 481                "        ja  0b\n"
 482                "        sfence \n"
 483                "5:      movl  %0, %%eax\n"
 484                "        shrl  $2, %0\n"
 485                "        andl $3, %%eax\n"
 486                "        cld\n"
 487                "6:      rep; movsl\n"
 488                "        movl %%eax,%0\n"
 489                "7:      rep; movsb\n"
 490                "8:\n"
 491                ".section .fixup,\"ax\"\n"
 492                "9:      lea 0(%%eax,%0,4),%0\n"
 493                "16:     pushl %0\n"
 494                "        pushl %%eax\n"
 495                "        xorl %%eax,%%eax\n"
 496                "        rep; stosb\n"
 497                "        popl %%eax\n"
 498                "        popl %0\n"
 499                "        jmp 8b\n"
 500                ".previous\n"
 501                ".section __ex_table,\"a\"\n"
 502                "        .align 4\n"
 503                "        .long 0b,16b\n"
 504                "        .long 1b,16b\n"
 505                "        .long 2b,16b\n"
 506                "        .long 21b,16b\n"
 507                "        .long 3b,16b\n"
 508                "        .long 31b,16b\n"
 509                "        .long 4b,16b\n"
 510                "        .long 41b,16b\n"
 511                "        .long 10b,16b\n"
 512                "        .long 51b,16b\n"
 513                "        .long 11b,16b\n"
 514                "        .long 61b,16b\n"
 515                "        .long 12b,16b\n"
 516                "        .long 71b,16b\n"
 517                "        .long 13b,16b\n"
 518                "        .long 81b,16b\n"
 519                "        .long 14b,16b\n"
 520                "        .long 91b,16b\n"
 521                "        .long 6b,9b\n"
 522                "        .long 7b,16b\n"
 523                ".previous"
 524                : "=&c"(size), "=&D" (d0), "=&S" (d1)
 525                :  "1"(to), "2"(from), "0"(size)
 526                : "eax", "edx", "memory");
 527         return size;
 528 }
 529
 530 static unsigned long __copy_user_intel_nocache(void *to,
 531                                 const void __user *from, unsigned long size)
 532 {
 533         int d0, d1;
 534
 535         __asm__ __volatile__(
 536                "        .align 2,0x90\n"
 537                "0:      movl 32(%4), %%eax\n"
 538                "        cmpl $67, %0\n"
 539                "        jbe 2f\n"
 540                "1:      movl 64(%4), %%eax\n"
 541                "        .align 2,0x90\n"
 542                "2:      movl 0(%4), %%eax\n"
 543                "21:     movl 4(%4), %%edx\n"
 544                "        movnti %%eax, 0(%3)\n"
 545                "        movnti %%edx, 4(%3)\n"
 546                "3:      movl 8(%4), %%eax\n"
 547                "31:     movl 12(%4),%%edx\n"
 548                "        movnti %%eax, 8(%3)\n"
 549                "        movnti %%edx, 12(%3)\n"
 550                "4:      movl 16(%4), %%eax\n"
 551                "41:     movl 20(%4), %%edx\n"
 552                "        movnti %%eax, 16(%3)\n"
 553                "        movnti %%edx, 20(%3)\n"
 554                "10:     movl 24(%4), %%eax\n"
 555                "51:     movl 28(%4), %%edx\n"
 556                "        movnti %%eax, 24(%3)\n"
 557                "        movnti %%edx, 28(%3)\n"
 558                "11:     movl 32(%4), %%eax\n"
 559                "61:     movl 36(%4), %%edx\n"
 560                "        movnti %%eax, 32(%3)\n"
 561                "        movnti %%edx, 36(%3)\n"
 562                "12:     movl 40(%4), %%eax\n"
 563                "71:     movl 44(%4), %%edx\n"
 564                "        movnti %%eax, 40(%3)\n"
 565                "        movnti %%edx, 44(%3)\n"
 566                "13:     movl 48(%4), %%eax\n"
 567                "81:     movl 52(%4), %%edx\n"
 568                "        movnti %%eax, 48(%3)\n"
 569                "        movnti %%edx, 52(%3)\n"
 570                "14:     movl 56(%4), %%eax\n"
 571                "91:     movl 60(%4), %%edx\n"
 572                "        movnti %%eax, 56(%3)\n"
 573                "        movnti %%edx, 60(%3)\n"
 574                "        addl $-64, %0\n"
 575                "        addl $64, %4\n"
 576                "        addl $64, %3\n"
 577                "        cmpl $63, %0\n"
 578                "        ja  0b\n"
 579                "        sfence \n"
 580                "5:      movl  %0, %%eax\n"
 581                "        shrl  $2, %0\n"
 582                "        andl $3, %%eax\n"
 583                "        cld\n"
 584                "6:      rep; movsl\n"
 585                "        movl %%eax,%0\n"
 586                "7:      rep; movsb\n"
 587                "8:\n"
 588                ".section .fixup,\"ax\"\n"
 589                "9:      lea 0(%%eax,%0,4),%0\n"
 590                "16:     jmp 8b\n"
 591                ".previous\n"
 592                ".section __ex_table,\"a\"\n"
 593                "        .align 4\n"
 594                "        .long 0b,16b\n"
 595                "        .long 1b,16b\n"
 596                "        .long 2b,16b\n"
 597                "        .long 21b,16b\n"
 598                "        .long 3b,16b\n"
 599                "        .long 31b,16b\n"
 600                "        .long 4b,16b\n"
 601                "        .long 41b,16b\n"
 602                "        .long 10b,16b\n"
 603                "        .long 51b,16b\n"
 604                "        .long 11b,16b\n"
 605                "        .long 61b,16b\n"
 606                "        .long 12b,16b\n"
 607                "        .long 71b,16b\n"
 608                "        .long 13b,16b\n"
 609                "        .long 81b,16b\n"
 610                "        .long 14b,16b\n"
 611                "        .long 91b,16b\n"
 612                "        .long 6b,9b\n"
 613                "        .long 7b,16b\n"
 614                ".previous"
 615                : "=&c"(size), "=&D" (d0), "=&S" (d1)
 616                :  "1"(to), "2"(from), "0"(size)
 617                : "eax", "edx", "memory");
 618         return size;
 619 }
 620
 621 #else
 622
 623 /*
 624  * Leave these declared but undefined.  They should not be any references to
 625  * them
 626  */
 627 unsigned long __copy_user_zeroing_intel(void *to, const void __user *from,
 628                                         unsigned long size);
 629 unsigned long __copy_user_intel(void __user *to, const void *from,
 630                                         unsigned long size);
 631 unsigned long __copy_user_zeroing_intel_nocache(void *to,
 632                                 const void __user *from, unsigned long size);
 633 #endif /* CONFIG_X86_INTEL_USERCOPY */
 634
 635 /* Generic arbitrary sized copy.  */
 636 #define __copy_user(to,from,size)                                       \
 637 do {                                                                    \
 638         int __d0, __d1, __d2;                                           \
 639         __asm__ __volatile__(                                           \
 640                 "       cmp  $7,%0\n"                                   \
 641                 "       jbe  1f\n"                                      \
 642                 "       movl %1,%0\n"                                   \
 643                 "       negl %0\n"                                      \
 644                 "       andl $7,%0\n"                                   \
 645                 "       subl %0,%3\n"                                   \
 646                 "4:     rep; movsb\n"                                   \
 647                 "       movl %3,%0\n"                                   \
 648                 "       shrl $2,%0\n"                                   \
 649                 "       andl $3,%3\n"                                   \
 650                 "       .align 2,0x90\n"                                \
 651                 "0:     rep; movsl\n"                                   \
 652                 "       movl %3,%0\n"                                   \
 653                 "1:     rep; movsb\n"                                   \
 654                 "2:\n"                                                  \
 655                 ".section .fixup,\"ax\"\n"                              \
 656                 "5:     addl %3,%0\n"                                   \
 657                 "       jmp 2b\n"                                       \
 658                 "3:     lea 0(%3,%0,4),%0\n"                            \
 659                 "       jmp 2b\n"                                       \
 660                 ".previous\n"                                           \
 661                 ".section __ex_table,\"a\"\n"                           \
 662                 "       .align 4\n"                                     \
 663                 "       .long 4b,5b\n"                                  \
 664                 "       .long 0b,3b\n"                                  \
 665                 "       .long 1b,2b\n"                                  \
 666                 ".previous"                                             \
 667                 : "=&c"(size), "=&D" (__d0), "=&S" (__d1), "=r"(__d2)   \
 668                 : "3"(size), "0"(size), "1"(to), "2"(from)              \
 669                 : "memory");                                            \
 670 } while (0)
 671
 672 #define __copy_user_zeroing(to,from,size)                               \
 673 do {                                                                    \
 674         int __d0, __d1, __d2;                                           \
 675         __asm__ __volatile__(                                           \
 676                 "       cmp  $7,%0\n"                                   \
 677                 "       jbe  1f\n"                                      \
 678                 "       movl %1,%0\n"                                   \
 679                 "       negl %0\n"                                      \
 680                 "       andl $7,%0\n"                                   \
 681                 "       subl %0,%3\n"                                   \
 682                 "4:     rep; movsb\n"                                   \
 683                 "       movl %3,%0\n"                                   \
 684                 "       shrl $2,%0\n"                                   \
 685                 "       andl $3,%3\n"                                   \
 686                 "       .align 2,0x90\n"                                \
 687                 "0:     rep; movsl\n"                                   \
 688                 "       movl %3,%0\n"                                   \
 689                 "1:     rep; movsb\n"                                   \
 690                 "2:\n"                                                  \
 691                 ".section .fixup,\"ax\"\n"                              \
 692                 "5:     addl %3,%0\n"                                   \
 693                 "       jmp 6f\n"                                       \
 694                 "3:     lea 0(%3,%0,4),%0\n"                            \
 695                 "6:     pushl %0\n"                                     \
 696                 "       pushl %%eax\n"                                  \
 697                 "       xorl %%eax,%%eax\n"                             \
 698                 "       rep; stosb\n"                                   \
 699                 "       popl %%eax\n"                                   \
 700                 "       popl %0\n"                                      \
 701                 "       jmp 2b\n"                                       \
 702                 ".previous\n"                                           \
 703                 ".section __ex_table,\"a\"\n"                           \
 704                 "       .align 4\n"                                     \
 705                 "       .long 4b,5b\n"                                  \
 706                 "       .long 0b,3b\n"                                  \
 707                 "       .long 1b,6b\n"                                  \
 708                 ".previous"                                             \
 709                 : "=&c"(size), "=&D" (__d0), "=&S" (__d1), "=r"(__d2)   \
 710                 : "3"(size), "0"(size), "1"(to), "2"(from)              \
 711                 : "memory");                                            \
 712 } while (0)
 713
 714 unsigned long __copy_to_user_ll(void __user *to, const void *from,
 715                                 unsigned long n)
 716 {
 717         BUG_ON((long) n < 0);
 718 #ifndef CONFIG_X86_WP_WORKS_OK
 719         if (unlikely(boot_cpu_data.wp_works_ok == 0) &&
 720                         ((unsigned long )to) < TASK_SIZE) {
 721                 /*
 722                  * CPU does not honor the WP bit when writing
 723                  * from supervisory mode, and due to preemption or SMP,
 724                  * the page tables can change at any time.
 725                  * Do it manually.      Manfred <manfred@colorfullife.com>
 726                  */
 727                 while (n) {
 728                         unsigned long offset = ((unsigned long)to)%PAGE_SIZE;
 729                         unsigned long len = PAGE_SIZE - offset;
 730                         int retval;
 731                         struct page *pg;
 732                         void *maddr;
 733
 734                         if (len > n)
 735                                 len = n;
 736
 737 survive:
 738                         down_read(&current->mm->mmap_sem);
 739                         retval = get_user_pages(current, current->mm,
 740                                         (unsigned long )to, 1, 1, 0, &pg, NULL);
 741
 742                         if (retval == -ENOMEM && current->pid == 1) {
 743                                 up_read(&current->mm->mmap_sem);
 744                                 blk_congestion_wait(WRITE, HZ/50);
 745                                 goto survive;
 746                         }
 747
 748                         if (retval != 1) {
 749                                 up_read(&current->mm->mmap_sem);
 750                                 break;
 751                         }
 752
 753                         maddr = kmap_atomic(pg, KM_USER0);
 754                         memcpy(maddr + offset, from, len);
 755                         kunmap_atomic(maddr, KM_USER0);
 756                         set_page_dirty_lock(pg);
 757                         put_page(pg);
 758                         up_read(&current->mm->mmap_sem);
 759
 760                         from += len;
 761                         to += len;
 762                         n -= len;
 763                 }
 764                 return n;
 765         }
 766 #endif
 767         if (movsl_is_ok(to, from, n))
 768                 __copy_user(to, from, n);
 769         else
 770                 n = __copy_user_intel(to, from, n);
 771         return n;
 772 }
 773 EXPORT_SYMBOL(__copy_to_user_ll);
 774
 775 unsigned long __copy_from_user_ll(void *to, const void __user *from,
 776                                         unsigned long n)
 777 {
 778         BUG_ON((long)n < 0);
 779         if (movsl_is_ok(to, from, n))
 780                 __copy_user_zeroing(to, from, n);
 781         else
 782                 n = __copy_user_zeroing_intel(to, from, n);
 783         return n;
 784 }
 785 EXPORT_SYMBOL(__copy_from_user_ll);
 786
 787 unsigned long __copy_from_user_ll_nozero(void *to, const void __user *from,
 788                                          unsigned long n)
 789 {
 790         BUG_ON((long)n < 0);
 791         if (movsl_is_ok(to, from, n))
 792                 __copy_user(to, from, n);
 793         else
 794                 n = __copy_user_intel((void __user *)to,
 795                                       (const void *)from, n);
 796         return n;
 797 }
 798 EXPORT_SYMBOL(__copy_from_user_ll_nozero);
 799
 800 unsigned long __copy_from_user_ll_nocache(void *to, const void __user *from,
 801                                         unsigned long n)
 802 {
 803         BUG_ON((long)n < 0);
 804 #ifdef CONFIG_X86_INTEL_USERCOPY
 805         if ( n > 64 && cpu_has_xmm2)
 806                 n = __copy_user_zeroing_intel_nocache(to, from, n);
 807         else
 808                 __copy_user_zeroing(to, from, n);
 809 #else
 810         __copy_user_zeroing(to, from, n);
 811 #endif
 812         return n;
 813 }
 814
 815 unsigned long __copy_from_user_ll_nocache_nozero(void *to, const void __user *from,
 816                                         unsigned long n)
 817 {
 818         BUG_ON((long)n < 0);
 819 #ifdef CONFIG_X86_INTEL_USERCOPY
 820         if ( n > 64 && cpu_has_xmm2)
 821                 n = __copy_user_intel_nocache(to, from, n);
 822         else
 823                 __copy_user(to, from, n);
 824 #else
 825         __copy_user(to, from, n);
 826 #endif
 827         return n;
 828 }
 829
 830 /**
 831  * copy_to_user: - Copy a block of data into user space.
 832  * @to:   Destination address, in user space.
 833  * @from: Source address, in kernel space.
 834  * @n:    Number of bytes to copy.
 835  *
 836  * Context: User context only.  This function may sleep.
 837  *
 838  * Copy data from kernel space to user space.
 839  *
 840  * Returns number of bytes that could not be copied.
 841  * On success, this will be zero.
 842  */
 843 unsigned long
 844 copy_to_user(void __user *to, const void *from, unsigned long n)
 845 {
 846         might_sleep();
 847         BUG_ON((long) n < 0);
 848         if (access_ok(VERIFY_WRITE, to, n))
 849                 n = __copy_to_user(to, from, n);
 850         return n;
 851 }
 852 EXPORT_SYMBOL(copy_to_user);
 853
 854 /**
 855  * copy_from_user: - Copy a block of data from user space.
 856  * @to:   Destination address, in kernel space.
 857  * @from: Source address, in user space.
 858  * @n:    Number of bytes to copy.
 859  *
 860  * Context: User context only.  This function may sleep.
 861  *
 862  * Copy data from user space to kernel space.
 863  *
 864  * Returns number of bytes that could not be copied.
 865  * On success, this will be zero.
 866  *
 867  * If some data could not be copied, this function will pad the copied
 868  * data to the requested size using zero bytes.
 869  */
 870 unsigned long
 871 copy_from_user(void *to, const void __user *from, unsigned long n)
 872 {
 873         might_sleep();
 874         BUG_ON((long) n < 0);
 875         if (access_ok(VERIFY_READ, from, n))
 876                 n = __copy_from_user(to, from, n);
 877         else
 878                 memset(to, 0, n);
 879         return n;
 880 }
 881 EXPORT_SYMBOL(copy_from_user);