arch/x86_64/mm/extable.c

   1 /*
   2  * linux/arch/x86_64/mm/extable.c
   3  */
   4
   5 #include <linux/config.h>
   6 #include <linux/module.h>
   7 #include <linux/spinlock.h>
   8 #include <linux/init.h>
   9 #include <asm/uaccess.h>
  10
  11 /* Simple binary search */
  12 const struct exception_table_entry *
  13 search_extable(const struct exception_table_entry *first,
  14                const struct exception_table_entry *last,
  15                unsigned long value)
  16 {
  17         /* Work around a B stepping K8 bug */
  18         if ((value >> 32) == 0)
  19                 value |= 0xffffffffUL << 32;
  20
  21         while (first <= last) {
  22                 const struct exception_table_entry *mid;
  23                 long diff;
  24
  25                 mid = (last - first) / 2 + first;
  26                 diff = mid->insn - value;
  27                 if (diff == 0)
  28                         return mid;
  29                 else if (diff < 0)
  30                         first = mid+1;
  31                 else
  32                         last = mid-1;
  33         }
  34         return NULL;
  35 }