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#include <linux/module.h>
#include <asm/uaccess.h>
#include <asm/traps.h>
typedef bool (*ex_handler_t)(const struct exception_table_entry *,
struct pt_regs *, int);
static inline unsigned long
ex_fixup_addr(const struct exception_table_entry *x)
{
return (unsigned long)&x->fixup + x->fixup;
}
static inline ex_handler_t
ex_fixup_handler(const struct exception_table_entry *x)
{
return (ex_handler_t)((unsigned long)&x->handler + x->handler);
}
bool ex_handler_default(const struct exception_table_entry *fixup,
struct pt_regs *regs, int trapnr)
{
regs->ip = ex_fixup_addr(fixup);
return true;
}
EXPORT_SYMBOL(ex_handler_default);
bool ex_handler_fault(const struct exception_table_entry *fixup,
struct pt_regs *regs, int trapnr)
{
regs->ip = ex_fixup_addr(fixup);
regs->ax = trapnr;
return true;
}
EXPORT_SYMBOL_GPL(ex_handler_fault);
bool ex_handler_ext(const struct exception_table_entry *fixup,
struct pt_regs *regs, int trapnr)
{
/* Special hack for uaccess_err */
current_thread_info()->uaccess_err = 1;
regs->ip = ex_fixup_addr(fixup);
return true;
}
EXPORT_SYMBOL(ex_handler_ext);
bool ex_has_fault_handler(unsigned long ip)
{
const struct exception_table_entry *e;
ex_handler_t handler;
e = search_exception_tables(ip);
if (!e)
return false;
handler = ex_fixup_handler(e);
return handler == ex_handler_fault;
}
int fixup_exception(struct pt_regs *regs, int trapnr)
{
const struct exception_table_entry *e;
ex_handler_t handler;
#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
e = search_exception_tables(regs->ip);
if (!e)
return 0;
handler = ex_fixup_handler(e);
return handler(e, regs, trapnr);
}
extern unsigned int early_recursion_flag;
/* Restricted version used during very early boot */
void __init early_fixup_exception(struct pt_regs *regs, int trapnr)
{
/* Ignore early NMIs. */
if (trapnr == X86_TRAP_NMI)
return;
if (early_recursion_flag > 2)
goto halt_loop;
if (regs->cs != __KERNEL_CS)
goto fail;
if (fixup_exception(regs, trapnr))
return;
fail:
early_printk("PANIC: early exception 0x%02x IP %lx:%lx error %lx cr2 0x%lx\n",
(unsigned)trapnr, (unsigned long)regs->cs, regs->ip,
regs->orig_ax, read_cr2());
show_regs(regs);
halt_loop:
while (true)
halt();
}
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