1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _ASM_X86_EXTABLE_H
3#define _ASM_X86_EXTABLE_H
4/*
5 * The exception table consists of triples of addresses relative to the
6 * exception table entry itself. The first address is of an instruction
7 * that is allowed to fault, the second is the target at which the program
8 * should continue. The third is a handler function to deal with the fault
9 * caused by the instruction in the first field.
10 *
11 * All the routines below use bits of fixup code that are out of line
12 * with the main instruction path.  This means when everything is well,
13 * we don't even have to jump over them.  Further, they do not intrude
14 * on our cache or tlb entries.
15 */
16
17struct exception_table_entry {
18	int insn, fixup, handler;
19};
20struct pt_regs;
21
22#define ARCH_HAS_RELATIVE_EXTABLE
23
24#define swap_ex_entry_fixup(a, b, tmp, delta)			\
25	do {							\
26		(a)->fixup = (b)->fixup + (delta);		\
27		(b)->fixup = (tmp).fixup - (delta);		\
28		(a)->handler = (b)->handler + (delta);		\
29		(b)->handler = (tmp).handler - (delta);		\
30	} while (0)
31
32enum handler_type {
33	EX_HANDLER_NONE,
34	EX_HANDLER_FAULT,
35	EX_HANDLER_UACCESS,
36	EX_HANDLER_OTHER
37};
38
39extern int fixup_exception(struct pt_regs *regs, int trapnr,
40			   unsigned long error_code, unsigned long fault_addr);
41extern int fixup_bug(struct pt_regs *regs, int trapnr);
42extern enum handler_type ex_get_fault_handler_type(unsigned long ip);
43extern void early_fixup_exception(struct pt_regs *regs, int trapnr);
44
45#endif
46