1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __ASM_EXTABLE_H
3 #define __ASM_EXTABLE_H
4
5 /*
6 * The exception table consists of pairs of relative offsets: the first
7 * is the relative offset to an instruction that is allowed to fault,
8 * and the second is the relative offset at which the program should
9 * continue. No registers are modified, so it is entirely up to the
10 * continuation code to figure out what to do.
11 *
12 * All the routines below use bits of fixup code that are out of line
13 * with the main instruction path. This means when everything is well,
14 * we don't even have to jump over them. Further, they do not intrude
15 * on our cache or tlb entries.
16 */
17
18 struct exception_table_entry
19 {
20 int insn, fixup;
21 short type, data;
22 };
23
24 #define ARCH_HAS_RELATIVE_EXTABLE
25
26 #define swap_ex_entry_fixup(a, b, tmp, delta) \
27 do { \
28 (a)->fixup = (b)->fixup + (delta); \
29 (b)->fixup = (tmp).fixup - (delta); \
30 (a)->type = (b)->type; \
31 (b)->type = (tmp).type; \
32 (a)->data = (b)->data; \
33 (b)->data = (tmp).data; \
34 } while (0)
35
36 #ifdef CONFIG_BPF_JIT
37 bool ex_handler_bpf(const struct exception_table_entry *ex,
38 struct pt_regs *regs);
39 #else /* !CONFIG_BPF_JIT */
40 static inline
41 bool ex_handler_bpf(const struct exception_table_entry *ex,
42 struct pt_regs *regs)
43 {
44 return false;
45 }
46 #endif /* !CONFIG_BPF_JIT */
47
48 bool fixup_exception(struct pt_regs *regs);
49 #endif
50
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