x86: unify arch/x86/mm/Makefile
[linux-2.6.git] / arch / x86 / mm / extable.c
1 #include <linux/module.h>
2 #include <linux/spinlock.h>
3 #include <asm/uaccess.h>
4
5
6 int fixup_exception(struct pt_regs *regs)
7 {
8         const struct exception_table_entry *fixup;
9
10 #ifdef CONFIG_PNPBIOS
11         if (unlikely(SEGMENT_IS_PNP_CODE(regs->cs))) {
12                 extern u32 pnp_bios_fault_eip, pnp_bios_fault_esp;
13                 extern u32 pnp_bios_is_utter_crap;
14                 pnp_bios_is_utter_crap = 1;
15                 printk(KERN_CRIT "PNPBIOS fault.. attempting recovery.\n");
16                 __asm__ volatile(
17                         "movl %0, %%esp\n\t"
18                         "jmp *%1\n\t"
19                         : : "g" (pnp_bios_fault_esp), "g" (pnp_bios_fault_eip));
20                 panic("do_trap: can't hit this");
21         }
22 #endif
23
24         fixup = search_exception_tables(regs->ip);
25         if (fixup) {
26                 regs->ip = fixup->fixup;
27                 return 1;
28         }
29
30         return 0;
31 }
32
33 #ifdef CONFIG_X86_64
34 /*
35  * Need to defined our own search_extable on X86_64 to work around
36  * a B stepping K8 bug.
37  */
38 const struct exception_table_entry *
39 search_extable(const struct exception_table_entry *first,
40                const struct exception_table_entry *last,
41                unsigned long value)
42 {
43         /* B stepping K8 bug */
44         if ((value >> 32) == 0)
45                 value |= 0xffffffffUL << 32;
46
47         while (first <= last) {
48                 const struct exception_table_entry *mid;
49                 long diff;
50
51                 mid = (last - first) / 2 + first;
52                 diff = mid->insn - value;
53                 if (diff == 0)
54                         return mid;
55                 else if (diff < 0)
56                         first = mid+1;
57                 else
58                         last = mid-1;
59         }
60         return NULL;
61 }
62 #endif