xref: /openbmc/linux/arch/x86/include/asm/extable.h (revision 6c33a6f4)
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
39