xref: /linux/arch/loongarch/include/asm/extable.h (revision dd093fb0)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_LOONGARCH_EXTABLE_H
3 #define _ASM_LOONGARCH_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 	int insn, fixup;
20 	short type, data;
21 };
22 
23 #define ARCH_HAS_RELATIVE_EXTABLE
24 
25 #define swap_ex_entry_fixup(a, b, tmp, delta)		\
26 do {							\
27 	(a)->fixup = (b)->fixup + (delta);		\
28 	(b)->fixup = (tmp).fixup - (delta);		\
29 	(a)->type = (b)->type;				\
30 	(b)->type = (tmp).type;				\
31 	(a)->data = (b)->data;				\
32 	(b)->data = (tmp).data;				\
33 } while (0)
34 
35 #ifdef CONFIG_BPF_JIT
36 bool ex_handler_bpf(const struct exception_table_entry *ex, struct pt_regs *regs);
37 #else
38 static inline
39 bool ex_handler_bpf(const struct exception_table_entry *ex, struct pt_regs *regs)
40 {
41 	return false;
42 }
43 #endif /* !CONFIG_BPF_JIT */
44 
45 bool fixup_exception(struct pt_regs *regs);
46 
47 #endif
48