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