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