satip-axe/kernel/arch/x86/mm/extable.c

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#include <linux/module.h>
#include <linux/spinlock.h>
#include <asm/uaccess.h>
int fixup_exception(struct pt_regs *regs)
{
const struct exception_table_entry *fixup;
#ifdef CONFIG_PNPBIOS
if (unlikely(SEGMENT_IS_PNP_CODE(regs->cs))) {
extern u32 pnp_bios_fault_eip, pnp_bios_fault_esp;
extern u32 pnp_bios_is_utter_crap;
pnp_bios_is_utter_crap = 1;
printk(KERN_CRIT "PNPBIOS fault.. attempting recovery.\n");
__asm__ volatile(
"movl %0, %%esp\n\t"
"jmp *%1\n\t"
: : "g" (pnp_bios_fault_esp), "g" (pnp_bios_fault_eip));
panic("do_trap: can't hit this");
}
#endif
fixup = search_exception_tables(regs->ip);
if (fixup) {
/* If fixup is less than 16, it means uaccess error */
if (fixup->fixup < 16) {
current_thread_info()->uaccess_err = -EFAULT;
regs->ip += fixup->fixup;
return 1;
}
regs->ip = fixup->fixup;
return 1;
}
return 0;
}
#ifdef CONFIG_X86_64
/*
* Need to defined our own search_extable on X86_64 to work around
* a B stepping K8 bug.
*/
const struct exception_table_entry *
search_extable(const struct exception_table_entry *first,
const struct exception_table_entry *last,
unsigned long value)
{
/* B stepping K8 bug */
if ((value >> 32) == 0)
value |= 0xffffffffUL << 32;
while (first <= last) {
const struct exception_table_entry *mid;
long diff;
mid = (last - first) / 2 + first;
diff = mid->insn - value;
if (diff == 0)
return mid;
else if (diff < 0)
first = mid+1;
else
last = mid-1;
}
return NULL;
}
#endif