arch/m68k/lib/uaccess.c

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file COPYING in the main directory of this archive
   4  * for more details.
   5  */
   6
   7 #include <linux/module.h>
   8 #include <asm/uaccess.h>
   9
  10 unsigned long __generic_copy_from_user(void *to, const void __user *from,
  11                                        unsigned long n)
  12 {
  13         unsigned long tmp, res;
  14
  15         asm volatile ("\n"
  16                 "       tst.l   %0\n"
  17                 "       jeq     2f\n"
  18                 "1:     "MOVES".l       (%1)+,%3\n"
  19                 "       move.l  %3,(%2)+\n"
  20                 "       subq.l  #1,%0\n"
  21                 "       jne     1b\n"
  22                 "2:     btst    #1,%5\n"
  23                 "       jeq     4f\n"
  24                 "3:     "MOVES".w       (%1)+,%3\n"
  25                 "       move.w  %3,(%2)+\n"
  26                 "4:     btst    #0,%5\n"
  27                 "       jeq     6f\n"
  28                 "5:     "MOVES".b       (%1)+,%3\n"
  29                 "       move.b  %3,(%2)+\n"
  30                 "6:\n"
  31                 "       .section .fixup,\"ax\"\n"
  32                 "       .even\n"
  33                 "10:    move.l  %0,%3\n"
  34                 "7:     clr.l   (%2)+\n"
  35                 "       subq.l  #1,%3\n"
  36                 "       jne     7b\n"
  37                 "       lsl.l   #2,%0\n"
  38                 "       btst    #1,%5\n"
  39                 "       jeq     8f\n"
  40                 "30:    clr.w   (%2)+\n"
  41                 "       addq.l  #2,%0\n"
  42                 "8:     btst    #0,%5\n"
  43                 "       jeq     6b\n"
  44                 "50:    clr.b   (%2)+\n"
  45                 "       addq.l  #1,%0\n"
  46                 "       jra     6b\n"
  47                 "       .previous\n"
  48                 "\n"
  49                 "       .section __ex_table,\"a\"\n"
  50                 "       .align  4\n"
  51                 "       .long   1b,10b\n"
  52                 "       .long   3b,30b\n"
  53                 "       .long   5b,50b\n"
  54                 "       .previous"
  55                 : "=d" (res), "+a" (from), "+a" (to), "=&r" (tmp)
  56                 : "0" (n / 4), "d" (n & 3));
  57
  58         return res;
  59 }
  60 EXPORT_SYMBOL(__generic_copy_from_user);
  61
  62 unsigned long __generic_copy_to_user(void __user *to, const void *from,
  63                                      unsigned long n)
  64 {
  65         unsigned long tmp, res;
  66
  67         asm volatile ("\n"
  68                 "       tst.l   %0\n"
  69                 "       jeq     4f\n"
  70                 "1:     move.l  (%1)+,%3\n"
  71                 "2:     "MOVES".l       %3,(%2)+\n"
  72                 "3:     subq.l  #1,%0\n"
  73                 "       jne     1b\n"
  74                 "4:     btst    #1,%5\n"
  75                 "       jeq     6f\n"
  76                 "       move.w  (%1)+,%3\n"
  77                 "5:     "MOVES".w       %3,(%2)+\n"
  78                 "6:     btst    #0,%5\n"
  79                 "       jeq     8f\n"
  80                 "       move.b  (%1)+,%3\n"
  81                 "7:     "MOVES".b  %3,(%2)+\n"
  82                 "8:\n"
  83                 "       .section .fixup,\"ax\"\n"
  84                 "       .even\n"
  85                 "20:    lsl.l   #2,%0\n"
  86                 "50:    add.l   %5,%0\n"
  87                 "       jra     8b\n"
  88                 "       .previous\n"
  89                 "\n"
  90                 "       .section __ex_table,\"a\"\n"
  91                 "       .align  4\n"
  92                 "       .long   2b,20b\n"
  93                 "       .long   3b,20b\n"
  94                 "       .long   5b,50b\n"
  95                 "       .long   6b,50b\n"
  96                 "       .long   7b,50b\n"
  97                 "       .long   8b,50b\n"
  98                 "       .previous"
  99                 : "=d" (res), "+a" (from), "+a" (to), "=&r" (tmp)
 100                 : "0" (n / 4), "d" (n & 3));
 101
 102         return res;
 103 }
 104 EXPORT_SYMBOL(__generic_copy_to_user);
 105
 106 /*
 107  * Copy a null terminated string from userspace.
 108  */
 109 long strncpy_from_user(char *dst, const char __user *src, long count)
 110 {
 111         long res;
 112         char c;
 113
 114         if (count <= 0)
 115                 return count;
 116
 117         asm volatile ("\n"
 118                 "1:     "MOVES".b       (%2)+,%4\n"
 119                 "       move.b  %4,(%1)+\n"
 120                 "       jeq     2f\n"
 121                 "       subq.l  #1,%3\n"
 122                 "       jne     1b\n"
 123                 "2:     sub.l   %3,%0\n"
 124                 "3:\n"
 125                 "       .section .fixup,\"ax\"\n"
 126                 "       .even\n"
 127                 "10:    move.l  %5,%0\n"
 128                 "       jra     3b\n"
 129                 "       .previous\n"
 130                 "\n"
 131                 "       .section __ex_table,\"a\"\n"
 132                 "       .align  4\n"
 133                 "       .long   1b,10b\n"
 134                 "       .previous"
 135                 : "=d" (res), "+a" (dst), "+a" (src), "+r" (count), "=&d" (c)
 136                 : "i" (-EFAULT), "0" (count));
 137
 138         return res;
 139 }
 140 EXPORT_SYMBOL(strncpy_from_user);
 141
 142 /*
 143  * Return the size of a string (including the ending 0)
 144  *
 145  * Return 0 on exception, a value greater than N if too long
 146  */
 147 long strnlen_user(const char __user *src, long n)
 148 {
 149         char c;
 150         long res;
 151
 152         asm volatile ("\n"
 153                 "1:     subq.l  #1,%1\n"
 154                 "       jmi     3f\n"
 155                 "2:     "MOVES".b       (%0)+,%2\n"
 156                 "       tst.b   %2\n"
 157                 "       jne     1b\n"
 158                 "       jra     4f\n"
 159                 "\n"
 160                 "3:     addq.l  #1,%0\n"
 161                 "4:     sub.l   %4,%0\n"
 162                 "5:\n"
 163                 "       .section .fixup,\"ax\"\n"
 164                 "       .even\n"
 165                 "20:    sub.l   %0,%0\n"
 166                 "       jra     5b\n"
 167                 "       .previous\n"
 168                 "\n"
 169                 "       .section __ex_table,\"a\"\n"
 170                 "       .align  4\n"
 171                 "       .long   2b,20b\n"
 172                 "       .previous\n"
 173                 : "=&a" (res), "+d" (n), "=&d" (c)
 174                 : "0" (src), "r" (src));
 175
 176         return res;
 177 }
 178 EXPORT_SYMBOL(strnlen_user);
 179
 180 /*
 181  * Zero Userspace
 182  */
 183
 184 unsigned long __clear_user(void __user *to, unsigned long n)
 185 {
 186         unsigned long res;
 187
 188         asm volatile ("\n"
 189                 "       tst.l   %0\n"
 190                 "       jeq     3f\n"
 191                 "1:     "MOVES".l       %2,(%1)+\n"
 192                 "2:     subq.l  #1,%0\n"
 193                 "       jne     1b\n"
 194                 "3:     btst    #1,%4\n"
 195                 "       jeq     5f\n"
 196                 "4:     "MOVES".w       %2,(%1)+\n"
 197                 "5:     btst    #0,%4\n"
 198                 "       jeq     7f\n"
 199                 "6:     "MOVES".b       %2,(%1)\n"
 200                 "7:\n"
 201                 "       .section .fixup,\"ax\"\n"
 202                 "       .even\n"
 203                 "10:    lsl.l   #2,%0\n"
 204                 "40:    add.l   %4,%0\n"
 205                 "       jra     7b\n"
 206                 "       .previous\n"
 207                 "\n"
 208                 "       .section __ex_table,\"a\"\n"
 209                 "       .align  4\n"
 210                 "       .long   1b,10b\n"
 211                 "       .long   2b,10b\n"
 212                 "       .long   4b,40b\n"
 213                 "       .long   5b,40b\n"
 214                 "       .long   6b,40b\n"
 215                 "       .long   7b,40b\n"
 216                 "       .previous"
 217                 : "=d" (res), "+a" (to)
 218                 : "r" (0), "0" (n / 4), "d" (n & 3));
 219
 220     return res;
 221 }
 222 EXPORT_SYMBOL(__clear_user);