blob: 7e8db53528a7618820bd338ccaaf1039a14f241f [file] [log] [blame]
Harvey Harrison6d485832008-01-30 13:31:41 +01001#include <linux/module.h>
2#include <linux/spinlock.h>
3#include <asm/uaccess.h>
4
5
6int 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 */
38const struct exception_table_entry *
39search_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