kitten/arch/x86_64/lib/extable.c

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