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 63