Pull bugzilla-8768 into release branch
[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 }