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 
23 struct pt_regs;
24 struct kprobe;
25 
26 typedef 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 */
38 extern __visible kprobe_opcode_t optprobe_template_entry[];
39 extern __visible kprobe_opcode_t optprobe_template_clac[];
40 extern __visible kprobe_opcode_t optprobe_template_val[];
41 extern __visible kprobe_opcode_t optprobe_template_call[];
42 extern __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 
49 extern const int kretprobe_blacklist_size;
50 
51 void arch_remove_kprobe(struct kprobe *p);
52 
53 extern void arch_kprobe_override_function(struct pt_regs *regs);
54 
55 /* Architecture specific copy of original instruction*/
56 struct arch_specific_insn {
57 	/* copy of the original instruction */
58 	kprobe_opcode_t *insn;
59 	/*
60 	 * boostable = 0: This instruction type is not boostable.
61 	 * boostable = 1: This instruction has been boosted: we have
62 	 * added a relative jump after the instruction copy in insn,
63 	 * so no single-step and fixup are needed (unless there's
64 	 * a post_handler).
65 	 */
66 	unsigned boostable:1;
67 	unsigned char size;	/* The size of insn */
68 	union {
69 		unsigned char opcode;
70 		struct {
71 			unsigned char type;
72 		} jcc;
73 		struct {
74 			unsigned char type;
75 			unsigned char asize;
76 		} loop;
77 		struct {
78 			unsigned char reg;
79 		} indirect;
80 	};
81 	s32 rel32;	/* relative offset must be s32, s16, or s8 */
82 	void (*emulate_op)(struct kprobe *p, struct pt_regs *regs);
83 	/* Number of bytes of text poked */
84 	int tp_len;
85 };
86 
87 struct arch_optimized_insn {
88 	/* copy of the original instructions */
89 	kprobe_opcode_t copied_insn[DISP32_SIZE];
90 	/* detour code buffer */
91 	kprobe_opcode_t *insn;
92 	/* the size of instructions copied to detour code buffer */
93 	size_t size;
94 };
95 
96 /* Return true (!0) if optinsn is prepared for optimization. */
arch_prepared_optinsn(struct arch_optimized_insn * optinsn)97 static inline int arch_prepared_optinsn(struct arch_optimized_insn *optinsn)
98 {
99 	return optinsn->size;
100 }
101 
102 struct prev_kprobe {
103 	struct kprobe *kp;
104 	unsigned long status;
105 	unsigned long old_flags;
106 	unsigned long saved_flags;
107 };
108 
109 /* per-cpu kprobe control block */
110 struct kprobe_ctlblk {
111 	unsigned long kprobe_status;
112 	unsigned long kprobe_old_flags;
113 	unsigned long kprobe_saved_flags;
114 	struct prev_kprobe prev_kprobe;
115 };
116 
117 extern int kprobe_fault_handler(struct pt_regs *regs, int trapnr);
118 extern int kprobe_exceptions_notify(struct notifier_block *self,
119 				    unsigned long val, void *data);
120 extern int kprobe_int3_handler(struct pt_regs *regs);
121 
122 #else
123 
kprobe_debug_handler(struct pt_regs * regs)124 static inline int kprobe_debug_handler(struct pt_regs *regs) { return 0; }
125 
126 #endif /* CONFIG_KPROBES */
127 #endif /* _ASM_X86_KPROBES_H */
128