xref: /freebsd/sys/cddl/dev/kinst/amd64/kinst_isa.h (revision 4e8d558c)
1 /*
2  * SPDX-License-Identifier: CDDL 1.0
3  *
4  * Copyright 2022 Christos Margiolis <christos@FreeBSD.org>
5  * Copyright 2022 Mark Johnston <markj@FreeBSD.org>
6  */
7 
8 #ifndef _KINST_ISA_H_
9 #define _KINST_ISA_H_
10 
11 #include <sys/types.h>
12 
13 #define KINST_PATCHVAL		0xcc
14 
15 /*
16  * Each trampoline is 32 bytes long and contains [instruction, jmp]. Since we
17  * have 2 instructions stored in the trampoline, and each of them can take up
18  * to 16 bytes, 32 bytes is enough to cover even the worst case scenario.
19  */
20 #define	KINST_TRAMP_SIZE	32
21 #define	KINST_TRAMPCHUNK_SIZE	PAGE_SIZE
22 
23 typedef uint8_t kinst_patchval_t;
24 
25 struct kinst_probe_md {
26 	int	flags;
27 	int	instlen;	/* original instr len */
28 	int	tinstlen;	/* trampoline instr len */
29 	uint8_t	template[16];	/* copied into thread tramps */
30 	int	dispoff;	/* offset of rip displacement */
31 
32 	/* operands to "call" instruction branch target */
33 	int	reg1;
34 	int	reg2;
35 	int	scale;
36 	int64_t	disp;
37 };
38 
39 #endif /* _KINST_ISA_H_ */
40