1/* SPDX-License-Identifier: GPL-2.0-or-later */
2#ifndef _ASM_X86_KPROBES_H
3#define _ASM_X86_KPROBES_H
4/*
5 *  Kernel Probes (KProbes)
6 *
7 * Copyright (C) IBM Corporation, 2002, 2004
8 *
9 * See arch/x86/kernel/kprobes.c for x86 kprobes history.
10 */
11
12#include <asm-generic/kprobes.h>
13
14#ifdef CONFIG_KPROBES
15#include <linux/types.h>
16#include <linux/ptrace.h>
17#include <linux/percpu.h>
18#include <asm/text-patching.h>
19#include <asm/insn.h>
20
21#define  __ARCH_WANT_KPROBES_INSN_SLOT
22
23struct pt_regs;
24struct kprobe;
25
26typedef u8 kprobe_opcode_t;
27
28#define MAX_STACK_SIZE 64
29#define CUR_STACK_SIZE(ADDR) \
30	(current_top_of_stack() - (unsigned long)(ADDR))
31#define MIN_STACK_SIZE(ADDR)				\
32	(MAX_STACK_SIZE < CUR_STACK_SIZE(ADDR) ?	\
33	 MAX_STACK_SIZE : CUR_STACK_SIZE(ADDR))
34
35#define flush_insn_slot(p)	do { } while (0)
36
37/* optinsn template addresses */
38extern __visible kprobe_opcode_t optprobe_template_entry[];
39extern __visible kprobe_opcode_t optprobe_template_clac[];
40extern __visible kprobe_opcode_t optprobe_template_val[];
41extern __visible kprobe_opcode_t optprobe_template_call[];
42extern __visible kprobe_opcode_t optprobe_template_end[];
43#define MAX_OPTIMIZED_LENGTH (MAX_INSN_SIZE + DISP32_SIZE)
44#define MAX_OPTINSN_SIZE 				\
45	(((unsigned long)optprobe_template_end -	\
46	  (unsigned long)optprobe_template_entry) +	\
47	 MAX_OPTIMIZED_LENGTH + JMP32_INSN_SIZE)
48
49extern const int kretprobe_blacklist_size;
50
51void arch_remove_kprobe(struct kprobe *p);
52asmlinkage void kretprobe_trampoline(void);
53
54extern void arch_kprobe_override_function(struct pt_regs *regs);
55
56/* Architecture specific copy of original instruction*/
57struct arch_specific_insn {
58	/* copy of the original instruction */
59	kprobe_opcode_t *insn;
60	/*
61	 * boostable = 0: This instruction type is not boostable.
62	 * boostable = 1: This instruction has been boosted: we have
63	 * added a relative jump after the instruction copy in insn,
64	 * so no single-step and fixup are needed (unless there's
65	 * a post_handler).
66	 */
67	unsigned boostable:1;
68	unsigned char size;	/* The size of insn */
69	union {
70		unsigned char opcode;
71		struct {
72			unsigned char type;
73		} jcc;
74		struct {
75			unsigned char type;
76			unsigned char asize;
77		} loop;
78		struct {
79			unsigned char reg;
80		} indirect;
81	};
82	s32 rel32;	/* relative offset must be s32, s16, or s8 */
83	void (*emulate_op)(struct kprobe *p, struct pt_regs *regs);
84	/* Number of bytes of text poked */
85	int tp_len;
86};
87
88struct arch_optimized_insn {
89	/* copy of the original instructions */
90	kprobe_opcode_t copied_insn[DISP32_SIZE];
91	/* detour code buffer */
92	kprobe_opcode_t *insn;
93	/* the size of instructions copied to detour code buffer */
94	size_t size;
95};
96
97/* Return true (!0) if optinsn is prepared for optimization. */
98static inline int arch_prepared_optinsn(struct arch_optimized_insn *optinsn)
99{
100	return optinsn->size;
101}
102
103struct prev_kprobe {
104	struct kprobe *kp;
105	unsigned long status;
106	unsigned long old_flags;
107	unsigned long saved_flags;
108};
109
110/* per-cpu kprobe control block */
111struct kprobe_ctlblk {
112	unsigned long kprobe_status;
113	unsigned long kprobe_old_flags;
114	unsigned long kprobe_saved_flags;
115	struct prev_kprobe prev_kprobe;
116};
117
118extern int kprobe_fault_handler(struct pt_regs *regs, int trapnr);
119extern int kprobe_exceptions_notify(struct notifier_block *self,
120				    unsigned long val, void *data);
121extern int kprobe_int3_handler(struct pt_regs *regs);
122
123#else
124
125static inline int kprobe_debug_handler(struct pt_regs *regs) { return 0; }
126
127#endif /* CONFIG_KPROBES */
128#endif /* _ASM_X86_KPROBES_H */
129