xref: /openbmc/linux/arch/x86/include/asm/extable.h (revision dd21bfa4)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_X86_EXTABLE_H
3 #define _ASM_X86_EXTABLE_H
4 
5 #include <asm/extable_fixup_types.h>
6 
7 /*
8  * The exception table consists of two addresses relative to the
9  * exception table entry itself and a type selector field.
10  *
11  * The first address is of an instruction that is allowed to fault, the
12  * second is the target at which the program should continue.
13  *
14  * The type entry is used by fixup_exception() to select the handler to
15  * deal with the fault caused by the instruction in the first field.
16  *
17  * All the routines below use bits of fixup code that are out of line
18  * with the main instruction path.  This means when everything is well,
19  * we don't even have to jump over them.  Further, they do not intrude
20  * on our cache or tlb entries.
21  */
22 
23 struct exception_table_entry {
24 	int insn, fixup, data;
25 };
26 struct pt_regs;
27 
28 #define ARCH_HAS_RELATIVE_EXTABLE
29 
30 #define swap_ex_entry_fixup(a, b, tmp, delta)			\
31 	do {							\
32 		(a)->fixup = (b)->fixup + (delta);		\
33 		(b)->fixup = (tmp).fixup - (delta);		\
34 		(a)->data = (b)->data;				\
35 		(b)->data = (tmp).data;				\
36 	} while (0)
37 
38 extern int fixup_exception(struct pt_regs *regs, int trapnr,
39 			   unsigned long error_code, unsigned long fault_addr);
40 extern int fixup_bug(struct pt_regs *regs, int trapnr);
41 extern int ex_get_fixup_type(unsigned long ip);
42 extern void early_fixup_exception(struct pt_regs *regs, int trapnr);
43 
44 #ifdef CONFIG_X86_MCE
45 extern void ex_handler_msr_mce(struct pt_regs *regs, bool wrmsr);
46 #else
47 static inline void ex_handler_msr_mce(struct pt_regs *regs, bool wrmsr) { }
48 #endif
49 
50 #if defined(CONFIG_BPF_JIT) && defined(CONFIG_X86_64)
51 bool ex_handler_bpf(const struct exception_table_entry *x, struct pt_regs *regs);
52 #else
53 static inline bool ex_handler_bpf(const struct exception_table_entry *x,
54 				  struct pt_regs *regs) { return false; }
55 #endif
56 
57 #endif
58