release/src-rt-6.x/linux/linux-2.6/arch/x86_64/mm/extable.c

   1 /*
   2  * linux/arch/x86_64/mm/extable.c
   3  */
   4
   5 #include <linux/module.h>
   6 #include <linux/spinlock.h>
   7 #include <linux/init.h>
   8 #include <asm/uaccess.h>
   9
  10 /* Simple binary search */
  11 const struct exception_table_entry *
  12 search_extable(const struct exception_table_entry *first,
  13                const struct exception_table_entry *last,
  14                unsigned long value)
  15 {
  16         /* Work around a B stepping K8 bug */
  17         if ((value >> 32) == 0)
  18                 value |= 0xffffffffUL << 32;
  19
  20         while (first <= last) {
  21                 const struct exception_table_entry *mid;
  22                 long diff;
  23
  24                 mid = (last - first) / 2 + first;
  25                 diff = mid->insn - value;
  26                 if (diff == 0)
  27                         return mid;
  28                 else if (diff < 0)
  29                         first = mid+1;
  30                 else
  31                         last = mid-1;
  32         }
  33         return NULL;
  34 }