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
17 struct exception_table_entry {
18 int insn, fixup, handler;
19 };
20 struct 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
32 extern int fixup_exception(struct pt_regs *regs, int trapnr,
33 unsigned long error_code, unsigned long fault_addr);
34 extern int fixup_bug(struct pt_regs *regs, int trapnr);
35 extern bool ex_has_fault_handler(unsigned long ip);
36 extern void early_fixup_exception(struct pt_regs *regs, int trapnr);
37
38 #endif