arch/x86/lib/usercopy_32.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 <linux/backing-dev.h>
  13 #include <linux/interrupt.h>
  14 #include <asm/uaccess.h>
  15 #include <asm/mmx.h>
  16
  17 static inline int __movsl_is_ok(unsigned long a1, unsigned long a2, unsigned long n)
  18 {
  19 #ifdef CONFIG_X86_INTEL_USERCOPY
  20         if (n >= 64 && ((a1 ^ a2) & movsl_mask.mask))
  21                 return 0;
  22 #endif
  23         return 1;
  24 }
  25 #define movsl_is_ok(a1, a2, n) \
  26         __movsl_is_ok((unsigned long)(a1), (unsigned long)(a2), (n))
  27
  28 /*
  29  * Copy a null terminated string from userspace.
  30  */
  31
  32 #define __do_strncpy_from_user(dst, src, count, res)                       \
  33 do {                                                                       \
  34         int __d0, __d1, __d2;                                              \
  35         might_fault();                                                     \
  36         __asm__ __volatile__(                                              \
  37                 "       testl %1,%1\n"                                     \
  38                 "       jz 2f\n"                                           \
  39                 "0:     lodsb\n"                                           \
  40                 "       stosb\n"                                           \
  41                 "       testb %%al,%%al\n"                                 \
  42                 "       jz 1f\n"                                           \
  43                 "       decl %1\n"                                         \
  44                 "       jnz 0b\n"                                          \
  45                 "1:     subl %1,%0\n"                                      \
  46                 "2:\n"                                                     \
  47                 ".section .fixup,\"ax\"\n"                                 \
  48                 "3:     movl %5,%0\n"                                      \
  49                 "       jmp 2b\n"                                          \
  50                 ".previous\n"                                              \
  51                 _ASM_EXTABLE(0b,3b)                                        \
  52                 : "=d"(res), "=c"(count), "=&a" (__d0), "=&S" (__d1),      \
  53                   "=&D" (__d2)                                             \
  54                 : "i"(-EFAULT), "0"(count), "1"(count), "3"(src), "4"(dst) \
  55                 : "memory");                                               \
  56 } while (0)
  57
  58 /**
  59  * __strncpy_from_user: - Copy a NUL terminated string from userspace, with less checking.
  60  * @dst:   Destination address, in kernel space.  This buffer must be at
  61  *         least @count bytes long.
  62  * @src:   Source address, in user space.
  63  * @count: Maximum number of bytes to copy, including the trailing NUL.
  64  *
  65  * Copies a NUL-terminated string from userspace to kernel space.
  66  * Caller must check the specified block with access_ok() before calling
  67  * this function.
  68  *
  69  * On success, returns the length of the string (not including the trailing
  70  * NUL).
  71  *
  72  * If access to userspace fails, returns -EFAULT (some data may have been
  73  * copied).
  74  *
  75  * If @count is smaller than the length of the string, copies @count bytes
  76  * and returns @count.
  77  */
  78 long
  79 __strncpy_from_user(char *dst, const char __user *src, long count)
  80 {
  81         long res;
  82         __do_strncpy_from_user(dst, src, count, res);
  83         return res;
  84 }
  85 EXPORT_SYMBOL(__strncpy_from_user);
  86
  87 /**
  88  * strncpy_from_user: - Copy a NUL terminated string from userspace.
  89  * @dst:   Destination address, in kernel space.  This buffer must be at
  90  *         least @count bytes long.
  91  * @src:   Source address, in user space.
  92  * @count: Maximum number of bytes to copy, including the trailing NUL.
  93  *
  94  * Copies a NUL-terminated string from userspace to kernel space.
  95  *
  96  * On success, returns the length of the string (not including the trailing
  97  * NUL).
  98  *
  99  * If access to userspace fails, returns -EFAULT (some data may have been
 100  * copied).
 101  *
 102  * If @count is smaller than the length of the string, copies @count bytes
 103  * and returns @count.
 104  */
 105 long
 106 strncpy_from_user(char *dst, const char __user *src, long count)
 107 {
 108         long res = -EFAULT;
 109         if (access_ok(VERIFY_READ, src, 1))
 110                 __do_strncpy_from_user(dst, src, count, res);
 111         return res;
 112 }
 113 EXPORT_SYMBOL(strncpy_from_user);
 114
 115 /*
 116  * Zero Userspace
 117  */
 118
 119 #define __do_clear_user(addr,size)                                      \
 120 do {                                                                    \
 121         int __d0;                                                       \
 122         might_fault();                                                  \
 123         __asm__ __volatile__(                                           \
 124                 "0:     rep; stosl\n"                                   \
 125                 "       movl %2,%0\n"                                   \
 126                 "1:     rep; stosb\n"                                   \
 127                 "2:\n"                                                  \
 128                 ".section .fixup,\"ax\"\n"                              \
 129                 "3:     lea 0(%2,%0,4),%0\n"                            \
 130                 "       jmp 2b\n"                                       \
 131                 ".previous\n"                                           \
 132                 _ASM_EXTABLE(0b,3b)                                     \
 133                 _ASM_EXTABLE(1b,2b)                                     \
 134                 : "=&c"(size), "=&D" (__d0)                             \
 135                 : "r"(size & 3), "0"(size / 4), "1"(addr), "a"(0));     \
 136 } while (0)
 137
 138 /**
 139  * clear_user: - Zero a block of memory in user space.
 140  * @to:   Destination address, in user space.
 141  * @n:    Number of bytes to zero.
 142  *
 143  * Zero a block of memory in user space.
 144  *
 145  * Returns number of bytes that could not be cleared.
 146  * On success, this will be zero.
 147  */
 148 unsigned long
 149 clear_user(void __user *to, unsigned long n)
 150 {
 151         if (access_ok(VERIFY_WRITE, to, n))
 152                 __do_clear_user(to, n);
 153         return n;
 154 }
 155 EXPORT_SYMBOL(clear_user);
 156
 157 /**
 158  * __clear_user: - Zero a block of memory in user space, with less checking.
 159  * @to:   Destination address, in user space.
 160  * @n:    Number of bytes to zero.
 161  *
 162  * Zero a block of memory in user space.  Caller must check
 163  * the specified block with access_ok() before calling this function.
 164  *
 165  * Returns number of bytes that could not be cleared.
 166  * On success, this will be zero.
 167  */
 168 unsigned long
 169 __clear_user(void __user *to, unsigned long n)
 170 {
 171         __do_clear_user(to, n);
 172         return n;
 173 }
 174 EXPORT_SYMBOL(__clear_user);
 175
 176 /**
 177  * strnlen_user: - Get the size of a string in user space.
 178  * @s: The string to measure.
 179  * @n: The maximum valid length
 180  *
 181  * Get the size of a NUL-terminated string in user space.
 182  *
 183  * Returns the size of the string INCLUDING the terminating NUL.
 184  * On exception, returns 0.
 185  * If the string is too long, returns a value greater than @n.
 186  */
 187 long strnlen_user(const char __user *s, long n)
 188 {
 189         unsigned long mask = -__addr_ok(s);
 190         unsigned long res, tmp;
 191
 192         might_fault();
 193
 194         __asm__ __volatile__(
 195                 "       testl %0, %0\n"
 196                 "       jz 3f\n"
 197                 "       andl %0,%%ecx\n"
 198                 "0:     repne; scasb\n"
 199                 "       setne %%al\n"
 200                 "       subl %%ecx,%0\n"
 201                 "       addl %0,%%eax\n"
 202                 "1:\n"
 203                 ".section .fixup,\"ax\"\n"
 204                 "2:     xorl %%eax,%%eax\n"
 205                 "       jmp 1b\n"
 206                 "3:     movb $1,%%al\n"
 207                 "       jmp 1b\n"
 208                 ".previous\n"
 209                 ".section __ex_table,\"a\"\n"
 210                 "       .align 4\n"
 211                 "       .long 0b,2b\n"
 212                 ".previous"
 213                 :"=r" (n), "=D" (s), "=a" (res), "=c" (tmp)
 214                 :"0" (n), "1" (s), "2" (0), "3" (mask)
 215                 :"cc");
 216         return res & mask;
 217 }
 218 EXPORT_SYMBOL(strnlen_user);
 219
 220 #ifdef CONFIG_X86_INTEL_USERCOPY
 221 static unsigned long
 222 __copy_user_intel(void __user *to, const void *from, unsigned long size)
 223 {
 224         int d0, d1;
 225         __asm__ __volatile__(
 226                        "       .align 2,0x90\n"
 227                        "1:     movl 32(%4), %%eax\n"
 228                        "       cmpl $67, %0\n"
 229                        "       jbe 3f\n"
 230                        "2:     movl 64(%4), %%eax\n"
 231                        "       .align 2,0x90\n"
 232                        "3:     movl 0(%4), %%eax\n"
 233                        "4:     movl 4(%4), %%edx\n"
 234                        "5:     movl %%eax, 0(%3)\n"
 235                        "6:     movl %%edx, 4(%3)\n"
 236                        "7:     movl 8(%4), %%eax\n"
 237                        "8:     movl 12(%4),%%edx\n"
 238                        "9:     movl %%eax, 8(%3)\n"
 239                        "10:    movl %%edx, 12(%3)\n"
 240                        "11:    movl 16(%4), %%eax\n"
 241                        "12:    movl 20(%4), %%edx\n"
 242                        "13:    movl %%eax, 16(%3)\n"
 243                        "14:    movl %%edx, 20(%3)\n"
 244                        "15:    movl 24(%4), %%eax\n"
 245                        "16:    movl 28(%4), %%edx\n"
 246                        "17:    movl %%eax, 24(%3)\n"
 247                        "18:    movl %%edx, 28(%3)\n"
 248                        "19:    movl 32(%4), %%eax\n"
 249                        "20:    movl 36(%4), %%edx\n"
 250                        "21:    movl %%eax, 32(%3)\n"
 251                        "22:    movl %%edx, 36(%3)\n"
 252                        "23:    movl 40(%4), %%eax\n"
 253                        "24:    movl 44(%4), %%edx\n"
 254                        "25:    movl %%eax, 40(%3)\n"
 255                        "26:    movl %%edx, 44(%3)\n"
 256                        "27:    movl 48(%4), %%eax\n"
 257                        "28:    movl 52(%4), %%edx\n"
 258                        "29:    movl %%eax, 48(%3)\n"
 259                        "30:    movl %%edx, 52(%3)\n"
 260                        "31:    movl 56(%4), %%eax\n"
 261                        "32:    movl 60(%4), %%edx\n"
 262                        "33:    movl %%eax, 56(%3)\n"
 263                        "34:    movl %%edx, 60(%3)\n"
 264                        "       addl $-64, %0\n"
 265                        "       addl $64, %4\n"
 266                        "       addl $64, %3\n"
 267                        "       cmpl $63, %0\n"
 268                        "       ja  1b\n"
 269                        "35:    movl  %0, %%eax\n"
 270                        "       shrl  $2, %0\n"
 271                        "       andl  $3, %%eax\n"
 272                        "       cld\n"
 273                        "99:    rep; movsl\n"
 274                        "36:    movl %%eax, %0\n"
 275                        "37:    rep; movsb\n"
 276                        "100:\n"
 277                        ".section .fixup,\"ax\"\n"
 278                        "101:   lea 0(%%eax,%0,4),%0\n"
 279                        "       jmp 100b\n"
 280                        ".previous\n"
 281                        ".section __ex_table,\"a\"\n"
 282                        "       .align 4\n"
 283                        "       .long 1b,100b\n"
 284                        "       .long 2b,100b\n"
 285                        "       .long 3b,100b\n"
 286                        "       .long 4b,100b\n"
 287                        "       .long 5b,100b\n"
 288                        "       .long 6b,100b\n"
 289                        "       .long 7b,100b\n"
 290                        "       .long 8b,100b\n"
 291                        "       .long 9b,100b\n"
 292                        "       .long 10b,100b\n"
 293                        "       .long 11b,100b\n"
 294                        "       .long 12b,100b\n"
 295                        "       .long 13b,100b\n"
 296                        "       .long 14b,100b\n"
 297                        "       .long 15b,100b\n"
 298                        "       .long 16b,100b\n"
 299                        "       .long 17b,100b\n"
 300                        "       .long 18b,100b\n"
 301                        "       .long 19b,100b\n"
 302                        "       .long 20b,100b\n"
 303                        "       .long 21b,100b\n"
 304                        "       .long 22b,100b\n"
 305                        "       .long 23b,100b\n"
 306                        "       .long 24b,100b\n"
 307                        "       .long 25b,100b\n"
 308                        "       .long 26b,100b\n"
 309                        "       .long 27b,100b\n"
 310                        "       .long 28b,100b\n"
 311                        "       .long 29b,100b\n"
 312                        "       .long 30b,100b\n"
 313                        "       .long 31b,100b\n"
 314                        "       .long 32b,100b\n"
 315                        "       .long 33b,100b\n"
 316                        "       .long 34b,100b\n"
 317                        "       .long 35b,100b\n"
 318                        "       .long 36b,100b\n"
 319                        "       .long 37b,100b\n"
 320                        "       .long 99b,101b\n"
 321                        ".previous"
 322                        : "=&c"(size), "=&D" (d0), "=&S" (d1)
 323                        :  "1"(to), "2"(from), "0"(size)
 324                        : "eax", "edx", "memory");
 325         return size;
 326 }
 327
 328 static unsigned long
 329 __copy_user_zeroing_intel(void *to, const void __user *from, unsigned long size)
 330 {
 331         int d0, d1;
 332         __asm__ __volatile__(
 333                        "        .align 2,0x90\n"
 334                        "0:      movl 32(%4), %%eax\n"
 335                        "        cmpl $67, %0\n"
 336                        "        jbe 2f\n"
 337                        "1:      movl 64(%4), %%eax\n"
 338                        "        .align 2,0x90\n"
 339                        "2:      movl 0(%4), %%eax\n"
 340                        "21:     movl 4(%4), %%edx\n"
 341                        "        movl %%eax, 0(%3)\n"
 342                        "        movl %%edx, 4(%3)\n"
 343                        "3:      movl 8(%4), %%eax\n"
 344                        "31:     movl 12(%4),%%edx\n"
 345                        "        movl %%eax, 8(%3)\n"
 346                        "        movl %%edx, 12(%3)\n"
 347                        "4:      movl 16(%4), %%eax\n"
 348                        "41:     movl 20(%4), %%edx\n"
 349                        "        movl %%eax, 16(%3)\n"
 350                        "        movl %%edx, 20(%3)\n"
 351                        "10:     movl 24(%4), %%eax\n"
 352                        "51:     movl 28(%4), %%edx\n"
 353                        "        movl %%eax, 24(%3)\n"
 354                        "        movl %%edx, 28(%3)\n"
 355                        "11:     movl 32(%4), %%eax\n"
 356                        "61:     movl 36(%4), %%edx\n"
 357                        "        movl %%eax, 32(%3)\n"
 358                        "        movl %%edx, 36(%3)\n"
 359                        "12:     movl 40(%4), %%eax\n"
 360                        "71:     movl 44(%4), %%edx\n"
 361                        "        movl %%eax, 40(%3)\n"
 362                        "        movl %%edx, 44(%3)\n"
 363                        "13:     movl 48(%4), %%eax\n"
 364                        "81:     movl 52(%4), %%edx\n"
 365                        "        movl %%eax, 48(%3)\n"
 366                        "        movl %%edx, 52(%3)\n"
 367                        "14:     movl 56(%4), %%eax\n"
 368                        "91:     movl 60(%4), %%edx\n"
 369                        "        movl %%eax, 56(%3)\n"
 370                        "        movl %%edx, 60(%3)\n"
 371                        "        addl $-64, %0\n"
 372                        "        addl $64, %4\n"
 373                        "        addl $64, %3\n"
 374                        "        cmpl $63, %0\n"
 375                        "        ja  0b\n"
 376                        "5:      movl  %0, %%eax\n"
 377                        "        shrl  $2, %0\n"
 378                        "        andl $3, %%eax\n"
 379                        "        cld\n"
 380                        "6:      rep; movsl\n"
 381                        "        movl %%eax,%0\n"
 382                        "7:      rep; movsb\n"
 383                        "8:\n"
 384                        ".section .fixup,\"ax\"\n"
 385                        "9:      lea 0(%%eax,%0,4),%0\n"
 386                        "16:     pushl %0\n"
 387                        "        pushl %%eax\n"
 388                        "        xorl %%eax,%%eax\n"
 389                        "        rep; stosb\n"
 390                        "        popl %%eax\n"
 391                        "        popl %0\n"
 392                        "        jmp 8b\n"
 393                        ".previous\n"
 394                        ".section __ex_table,\"a\"\n"
 395                        "        .align 4\n"
 396                        "        .long 0b,16b\n"
 397                        "        .long 1b,16b\n"
 398                        "        .long 2b,16b\n"
 399                        "        .long 21b,16b\n"
 400                        "        .long 3b,16b\n"
 401                        "        .long 31b,16b\n"
 402                        "        .long 4b,16b\n"
 403                        "        .long 41b,16b\n"
 404                        "        .long 10b,16b\n"
 405                        "        .long 51b,16b\n"
 406                        "        .long 11b,16b\n"
 407                        "        .long 61b,16b\n"
 408                        "        .long 12b,16b\n"
 409                        "        .long 71b,16b\n"
 410                        "        .long 13b,16b\n"
 411                        "        .long 81b,16b\n"
 412                        "        .long 14b,16b\n"
 413                        "        .long 91b,16b\n"
 414                        "        .long 6b,9b\n"
 415                        "        .long 7b,16b\n"
 416                        ".previous"
 417                        : "=&c"(size), "=&D" (d0), "=&S" (d1)
 418                        :  "1"(to), "2"(from), "0"(size)
 419                        : "eax", "edx", "memory");
 420         return size;
 421 }
 422
 423 /*
 424  * Non Temporal Hint version of __copy_user_zeroing_intel.  It is cache aware.
 425  * hyoshiok@miraclelinux.com
 426  */
 427
 428 static unsigned long __copy_user_zeroing_intel_nocache(void *to,
 429                                 const void __user *from, unsigned long size)
 430 {
 431         int d0, d1;
 432
 433         __asm__ __volatile__(
 434                "        .align 2,0x90\n"
 435                "0:      movl 32(%4), %%eax\n"
 436                "        cmpl $67, %0\n"
 437                "        jbe 2f\n"
 438                "1:      movl 64(%4), %%eax\n"
 439                "        .align 2,0x90\n"
 440                "2:      movl 0(%4), %%eax\n"
 441                "21:     movl 4(%4), %%edx\n"
 442                "        movnti %%eax, 0(%3)\n"
 443                "        movnti %%edx, 4(%3)\n"
 444                "3:      movl 8(%4), %%eax\n"
 445                "31:     movl 12(%4),%%edx\n"
 446                "        movnti %%eax, 8(%3)\n"
 447                "        movnti %%edx, 12(%3)\n"
 448                "4:      movl 16(%4), %%eax\n"
 449                "41:     movl 20(%4), %%edx\n"
 450                "        movnti %%eax, 16(%3)\n"
 451                "        movnti %%edx, 20(%3)\n"
 452                "10:     movl 24(%4), %%eax\n"
 453                "51:     movl 28(%4), %%edx\n"
 454                "        movnti %%eax, 24(%3)\n"
 455                "        movnti %%edx, 28(%3)\n"
 456                "11:     movl 32(%4), %%eax\n"
 457                "61:     movl 36(%4), %%edx\n"
 458                "        movnti %%eax, 32(%3)\n"
 459                "        movnti %%edx, 36(%3)\n"
 460                "12:     movl 40(%4), %%eax\n"
 461                "71:     movl 44(%4), %%edx\n"
 462                "        movnti %%eax, 40(%3)\n"
 463                "        movnti %%edx, 44(%3)\n"
 464                "13:     movl 48(%4), %%eax\n"
 465                "81:     movl 52(%4), %%edx\n"
 466                "        movnti %%eax, 48(%3)\n"
 467                "        movnti %%edx, 52(%3)\n"
 468                "14:     movl 56(%4), %%eax\n"
 469                "91:     movl 60(%4), %%edx\n"
 470                "        movnti %%eax, 56(%3)\n"
 471                "        movnti %%edx, 60(%3)\n"
 472                "        addl $-64, %0\n"
 473                "        addl $64, %4\n"
 474                "        addl $64, %3\n"
 475                "        cmpl $63, %0\n"
 476                "        ja  0b\n"
 477                "        sfence \n"
 478                "5:      movl  %0, %%eax\n"
 479                "        shrl  $2, %0\n"
 480                "        andl $3, %%eax\n"
 481                "        cld\n"
 482                "6:      rep; movsl\n"
 483                "        movl %%eax,%0\n"
 484                "7:      rep; movsb\n"
 485                "8:\n"
 486                ".section .fixup,\"ax\"\n"
 487                "9:      lea 0(%%eax,%0,4),%0\n"
 488                "16:     pushl %0\n"
 489                "        pushl %%eax\n"
 490                "        xorl %%eax,%%eax\n"
 491                "        rep; stosb\n"
 492                "        popl %%eax\n"
 493                "        popl %0\n"
 494                "        jmp 8b\n"
 495                ".previous\n"
 496                ".section __ex_table,\"a\"\n"
 497                "        .align 4\n"
 498                "        .long 0b,16b\n"
 499                "        .long 1b,16b\n"
 500                "        .long 2b,16b\n"
 501                "        .long 21b,16b\n"
 502                "        .long 3b,16b\n"
 503                "        .long 31b,16b\n"
 504                "        .long 4b,16b\n"
 505                "        .long 41b,16b\n"
 506                "        .long 10b,16b\n"
 507                "        .long 51b,16b\n"
 508                "        .long 11b,16b\n"
 509                "        .long 61b,16b\n"
 510                "        .long 12b,16b\n"
 511                "        .long 71b,16b\n"
 512                "        .long 13b,16b\n"
 513                "        .long 81b,16b\n"
 514                "        .long 14b,16b\n"
 515                "        .long 91b,16b\n"
 516                "        .long 6b,9b\n"
 517                "        .long 7b,16b\n"
 518                ".previous"
 519                : "=&c"(size), "=&D" (d0), "=&S" (d1)
 520                :  "1"(to), "2"(from), "0"(size)
 521                : "eax", "edx", "memory");
 522         return size;
 523 }
 524
 525 static unsigned long __copy_user_intel_nocache(void *to,
 526                                 const void __user *from, unsigned long size)
 527 {
 528         int d0, d1;
 529
 530         __asm__ __volatile__(
 531                "        .align 2,0x90\n"
 532                "0:      movl 32(%4), %%eax\n"
 533                "        cmpl $67, %0\n"
 534                "        jbe 2f\n"
 535                "1:      movl 64(%4), %%eax\n"
 536                "        .align 2,0x90\n"
 537                "2:      movl 0(%4), %%eax\n"
 538                "21:     movl 4(%4), %%edx\n"
 539                "        movnti %%eax, 0(%3)\n"
 540                "        movnti %%edx, 4(%3)\n"
 541                "3:      movl 8(%4), %%eax\n"
 542                "31:     movl 12(%4),%%edx\n"
 543                "        movnti %%eax, 8(%3)\n"
 544                "        movnti %%edx, 12(%3)\n"
 545                "4:      movl 16(%4), %%eax\n"
 546                "41:     movl 20(%4), %%edx\n"
 547                "        movnti %%eax, 16(%3)\n"
 548                "        movnti %%edx, 20(%3)\n"
 549                "10:     movl 24(%4), %%eax\n"
 550                "51:     movl 28(%4), %%edx\n"
 551                "        movnti %%eax, 24(%3)\n"
 552                "        movnti %%edx, 28(%3)\n"
 553                "11:     movl 32(%4), %%eax\n"
 554                "61:     movl 36(%4), %%edx\n"
 555                "        movnti %%eax, 32(%3)\n"
 556                "        movnti %%edx, 36(%3)\n"
 557                "12:     movl 40(%4), %%eax\n"
 558                "71:     movl 44(%4), %%edx\n"
 559                "        movnti %%eax, 40(%3)\n"
 560                "        movnti %%edx, 44(%3)\n"
 561                "13:     movl 48(%4), %%eax\n"
 562                "81:     movl 52(%4), %%edx\n"
 563                "        movnti %%eax, 48(%3)\n"
 564                "        movnti %%edx, 52(%3)\n"
 565                "14:     movl 56(%4), %%eax\n"
 566                "91:     movl 60(%4), %%edx\n"
 567                "        movnti %%eax, 56(%3)\n"
 568                "        movnti %%edx, 60(%3)\n"
 569                "        addl $-64, %0\n"
 570                "        addl $64, %4\n"
 571                "        addl $64, %3\n"
 572                "        cmpl $63, %0\n"
 573                "        ja  0b\n"
 574                "        sfence \n"
 575                "5:      movl  %0, %%eax\n"
 576                "        shrl  $2, %0\n"
 577                "        andl $3, %%eax\n"
 578                "        cld\n"
 579                "6:      rep; movsl\n"
 580                "        movl %%eax,%0\n"
 581                "7:      rep; movsb\n"
 582                "8:\n"
 583                ".section .fixup,\"ax\"\n"
 584                "9:      lea 0(%%eax,%0,4),%0\n"
 585                "16:     jmp 8b\n"
 586                ".previous\n"
 587                ".section __ex_table,\"a\"\n"
 588                "        .align 4\n"
 589                "        .long 0b,16b\n"
 590                "        .long 1b,16b\n"
 591                "        .long 2b,16b\n"
 592                "        .long 21b,16b\n"
 593                "        .long 3b,16b\n"
 594                "        .long 31b,16b\n"
 595                "        .long 4b,16b\n"
 596                "        .long 41b,16b\n"
 597                "        .long 10b,16b\n"
 598                "        .long 51b,16b\n"
 599                "        .long 11b,16b\n"
 600                "        .long 61b,16b\n"
 601                "        .long 12b,16b\n"
 602                "        .long 71b,16b\n"
 603                "        .long 13b,16b\n"
 604                "        .long 81b,16b\n"
 605                "        .long 14b,16b\n"
 606                "        .long 91b,16b\n"
 607                "        .long 6b,9b\n"
 608                "        .long 7b,16b\n"
 609                ".previous"
 610                : "=&c"(size), "=&D" (d0), "=&S" (d1)
 611                :  "1"(to), "2"(from), "0"(size)
 612                : "eax", "edx", "memory");
 613         return size;
 614 }
 615
 616 #else
 617
 618 /*
 619  * Leave these declared but undefined.  They should not be any references to
 620  * them
 621  */
 622 unsigned long __copy_user_zeroing_intel(void *to, const void __user *from,
 623                                         unsigned long size);
 624 unsigned long __copy_user_intel(void __user *to, const void *from,
 625                                         unsigned long size);
 626 unsigned long __copy_user_zeroing_intel_nocache(void *to,
 627                                 const void __user *from, unsigned long size);
 628 #endif /* CONFIG_X86_INTEL_USERCOPY */
 629
 630 /* Generic arbitrary sized copy.  */
 631 #define __copy_user(to, from, size)                                     \
 632 do {                                                                    \
 633         int __d0, __d1, __d2;                                           \
 634         __asm__ __volatile__(                                           \
 635                 "       cmp  $7,%0\n"                                   \
 636                 "       jbe  1f\n"                                      \
 637                 "       movl %1,%0\n"                                   \
 638                 "       negl %0\n"                                      \
 639                 "       andl $7,%0\n"                                   \
 640                 "       subl %0,%3\n"                                   \
 641                 "4:     rep; movsb\n"                                   \
 642                 "       movl %3,%0\n"                                   \
 643                 "       shrl $2,%0\n"                                   \
 644                 "       andl $3,%3\n"                                   \
 645                 "       .align 2,0x90\n"                                \
 646                 "0:     rep; movsl\n"                                   \
 647                 "       movl %3,%0\n"                                   \
 648                 "1:     rep; movsb\n"                                   \
 649                 "2:\n"                                                  \
 650                 ".section .fixup,\"ax\"\n"                              \
 651                 "5:     addl %3,%0\n"                                   \
 652                 "       jmp 2b\n"                                       \
 653                 "3:     lea 0(%3,%0,4),%0\n"                            \
 654                 "       jmp 2b\n"                                       \
 655                 ".previous\n"                                           \
 656                 ".section __ex_table,\"a\"\n"                           \
 657                 "       .align 4\n"                                     \
 658                 "       .long 4b,5b\n"                                  \
 659                 "       .long 0b,3b\n"                                  \
 660                 "       .long 1b,2b\n"                                  \
 661                 ".previous"                                             \
 662                 : "=&c"(size), "=&D" (__d0), "=&S" (__d1), "=r"(__d2)   \
 663                 : "3"(size), "0"(size), "1"(to), "2"(from)              \
 664                 : "memory");                                            \
 665 } while (0)
 666
 667 #define __copy_user_zeroing(to, from, size)                             \
 668 do {                                                                    \
 669         int __d0, __d1, __d2;                                           \
 670         __asm__ __volatile__(                                           \
 671                 "       cmp  $7,%0\n"                                   \
 672                 "       jbe  1f\n"                                      \
 673                 "       movl %1,%0\n"                                   \
 674                 "       negl %0\n"                                      \
 675                 "       andl $7,%0\n"                                   \
 676                 "       subl %0,%3\n"                                   \
 677                 "4:     rep; movsb\n"                                   \
 678                 "       movl %3,%0\n"                                   \
 679                 "       shrl $2,%0\n"                                   \
 680                 "       andl $3,%3\n"                                   \
 681                 "       .align 2,0x90\n"                                \
 682                 "0:     rep; movsl\n"                                   \
 683                 "       movl %3,%0\n"                                   \
 684                 "1:     rep; movsb\n"                                   \
 685                 "2:\n"                                                  \
 686                 ".section .fixup,\"ax\"\n"                              \
 687                 "5:     addl %3,%0\n"                                   \
 688                 "       jmp 6f\n"                                       \
 689                 "3:     lea 0(%3,%0,4),%0\n"                            \
 690                 "6:     pushl %0\n"                                     \
 691                 "       pushl %%eax\n"                                  \
 692                 "       xorl %%eax,%%eax\n"                             \
 693                 "       rep; stosb\n"                                   \
 694                 "       popl %%eax\n"                                   \
 695                 "       popl %0\n"                                      \
 696                 "       jmp 2b\n"                                       \
 697                 ".previous\n"                                           \
 698                 ".section __ex_table,\"a\"\n"                           \
 699                 "       .align 4\n"                                     \
 700                 "       .long 4b,5b\n"                                  \
 701                 "       .long 0b,3b\n"                                  \
 702                 "       .long 1b,6b\n"                                  \
 703                 ".previous"                                             \
 704                 : "=&c"(size), "=&D" (__d0), "=&S" (__d1), "=r"(__d2)   \
 705                 : "3"(size), "0"(size), "1"(to), "2"(from)              \
 706                 : "memory");                                            \
 707 } while (0)
 708
 709 unsigned long __copy_to_user_ll(void __user *to, const void *from,
 710                                 unsigned long n)
 711 {
 712 #ifndef CONFIG_X86_WP_WORKS_OK
 713         if (unlikely(boot_cpu_data.wp_works_ok == 0) &&
 714                         ((unsigned long)to) < TASK_SIZE) {
 715                 /*
 716                  * When we are in an atomic section (see
 717                  * mm/filemap.c:file_read_actor), return the full
 718                  * length to take the slow path.
 719                  */
 720                 if (in_atomic())
 721                         return n;
 722
 723                 /*
 724                  * CPU does not honor the WP bit when writing
 725                  * from supervisory mode, and due to preemption or SMP,
 726                  * the page tables can change at any time.
 727                  * Do it manually.      Manfred <manfred@colorfullife.com>
 728                  */
 729                 while (n) {
 730                         unsigned long offset = ((unsigned long)to)%PAGE_SIZE;
 731                         unsigned long len = PAGE_SIZE - offset;
 732                         int retval;
 733                         struct page *pg;
 734                         void *maddr;
 735
 736                         if (len > n)
 737                                 len = n;
 738
 739 survive:
 740                         down_read(&current->mm->mmap_sem);
 741                         retval = get_user_pages(current, current->mm,
 742                                         (unsigned long)to, 1, 1, 0, &pg, NULL);
 743
 744                         if (retval == -ENOMEM && is_global_init(current)) {
 745                                 up_read(&current->mm->mmap_sem);
 746                                 congestion_wait(WRITE, HZ/50);
 747                                 goto survive;
 748                         }
 749
 750                         if (retval != 1) {
 751                                 up_read(&current->mm->mmap_sem);
 752                                 break;
 753                         }
 754
 755                         maddr = kmap_atomic(pg, KM_USER0);
 756                         memcpy(maddr + offset, from, len);
 757                         kunmap_atomic(maddr, KM_USER0);
 758                         set_page_dirty_lock(pg);
 759                         put_page(pg);
 760                         up_read(&current->mm->mmap_sem);
 761
 762                         from += len;
 763                         to += len;
 764                         n -= len;
 765                 }
 766                 return n;
 767         }
 768 #endif
 769         if (movsl_is_ok(to, from, n))
 770                 __copy_user(to, from, n);
 771         else
 772                 n = __copy_user_intel(to, from, n);
 773         return n;
 774 }
 775 EXPORT_SYMBOL(__copy_to_user_ll);
 776
 777 unsigned long __copy_from_user_ll(void *to, const void __user *from,
 778                                         unsigned long n)
 779 {
 780         if (movsl_is_ok(to, from, n))
 781                 __copy_user_zeroing(to, from, n);
 782         else
 783                 n = __copy_user_zeroing_intel(to, from, n);
 784         return n;
 785 }
 786 EXPORT_SYMBOL(__copy_from_user_ll);
 787
 788 unsigned long __copy_from_user_ll_nozero(void *to, const void __user *from,
 789                                          unsigned long n)
 790 {
 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 #ifdef CONFIG_X86_INTEL_USERCOPY
 804         if (n > 64 && cpu_has_xmm2)
 805                 n = __copy_user_zeroing_intel_nocache(to, from, n);
 806         else
 807                 __copy_user_zeroing(to, from, n);
 808 #else
 809         __copy_user_zeroing(to, from, n);
 810 #endif
 811         return n;
 812 }
 813 EXPORT_SYMBOL(__copy_from_user_ll_nocache);
 814
 815 unsigned long __copy_from_user_ll_nocache_nozero(void *to, const void __user *from,
 816                                         unsigned long n)
 817 {
 818 #ifdef CONFIG_X86_INTEL_USERCOPY
 819         if (n > 64 && cpu_has_xmm2)
 820                 n = __copy_user_intel_nocache(to, from, n);
 821         else
 822                 __copy_user(to, from, n);
 823 #else
 824         __copy_user(to, from, n);
 825 #endif
 826         return n;
 827 }
 828 EXPORT_SYMBOL(__copy_from_user_ll_nocache_nozero);
 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         if (access_ok(VERIFY_WRITE, to, n))
 847                 n = __copy_to_user(to, from, n);
 848         return n;
 849 }
 850 EXPORT_SYMBOL(copy_to_user);
 851
 852 /**
 853  * copy_from_user: - Copy a block of data from user space.
 854  * @to:   Destination address, in kernel space.
 855  * @from: Source address, in user space.
 856  * @n:    Number of bytes to copy.
 857  *
 858  * Context: User context only.  This function may sleep.
 859  *
 860  * Copy data from user space to kernel space.
 861  *
 862  * Returns number of bytes that could not be copied.
 863  * On success, this will be zero.
 864  *
 865  * If some data could not be copied, this function will pad the copied
 866  * data to the requested size using zero bytes.
 867  */
 868 unsigned long
 869 copy_from_user(void *to, const void __user *from, unsigned long n)
 870 {
 871         if (access_ok(VERIFY_READ, from, n))
 872                 n = __copy_from_user(to, from, n);
 873         else
 874                 memset(to, 0, n);
 875         return n;
 876 }
 877 EXPORT_SYMBOL(copy_from_user);