xref: /openbmc/linux/arch/x86/include/asm/kprobes.h (revision 8dde5715)
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 #define BREAKPOINT_INSTRUCTION	0xcc
15 
16 #ifdef CONFIG_KPROBES
17 #include <linux/types.h>
18 #include <linux/ptrace.h>
19 #include <linux/percpu.h>
20 #include <asm/insn.h>
21 
22 #define  __ARCH_WANT_KPROBES_INSN_SLOT
23 
24 struct pt_regs;
25 struct kprobe;
26 
27 typedef u8 kprobe_opcode_t;
28 #define RELATIVEJUMP_OPCODE 0xe9
29 #define RELATIVEJUMP_SIZE 5
30 #define RELATIVECALL_OPCODE 0xe8
31 #define RELATIVE_ADDR_SIZE 4
32 #define MAX_STACK_SIZE 64
33 #define CUR_STACK_SIZE(ADDR) \
34 	(current_top_of_stack() - (unsigned long)(ADDR))
35 #define MIN_STACK_SIZE(ADDR)				\
36 	(MAX_STACK_SIZE < CUR_STACK_SIZE(ADDR) ?	\
37 	 MAX_STACK_SIZE : CUR_STACK_SIZE(ADDR))
38 
39 #define flush_insn_slot(p)	do { } while (0)
40 
41 /* optinsn template addresses */
42 extern __visible kprobe_opcode_t optprobe_template_entry[];
43 extern __visible kprobe_opcode_t optprobe_template_val[];
44 extern __visible kprobe_opcode_t optprobe_template_call[];
45 extern __visible kprobe_opcode_t optprobe_template_end[];
46 #define MAX_OPTIMIZED_LENGTH (MAX_INSN_SIZE + RELATIVE_ADDR_SIZE)
47 #define MAX_OPTINSN_SIZE 				\
48 	(((unsigned long)optprobe_template_end -	\
49 	  (unsigned long)optprobe_template_entry) +	\
50 	 MAX_OPTIMIZED_LENGTH + RELATIVEJUMP_SIZE)
51 
52 extern const int kretprobe_blacklist_size;
53 
54 void arch_remove_kprobe(struct kprobe *p);
55 asmlinkage void kretprobe_trampoline(void);
56 
57 extern void arch_kprobe_override_function(struct pt_regs *regs);
58 
59 /* Architecture specific copy of original instruction*/
60 struct arch_specific_insn {
61 	/* copy of the original instruction */
62 	kprobe_opcode_t *insn;
63 	/*
64 	 * boostable = false: This instruction type is not boostable.
65 	 * boostable = true: This instruction has been boosted: we have
66 	 * added a relative jump after the instruction copy in insn,
67 	 * so no single-step and fixup are needed (unless there's
68 	 * a post_handler).
69 	 */
70 	bool boostable;
71 	bool if_modifier;
72 };
73 
74 struct arch_optimized_insn {
75 	/* copy of the original instructions */
76 	kprobe_opcode_t copied_insn[RELATIVE_ADDR_SIZE];
77 	/* detour code buffer */
78 	kprobe_opcode_t *insn;
79 	/* the size of instructions copied to detour code buffer */
80 	size_t size;
81 };
82 
83 /* Return true (!0) if optinsn is prepared for optimization. */
84 static inline int arch_prepared_optinsn(struct arch_optimized_insn *optinsn)
85 {
86 	return optinsn->size;
87 }
88 
89 struct prev_kprobe {
90 	struct kprobe *kp;
91 	unsigned long status;
92 	unsigned long old_flags;
93 	unsigned long saved_flags;
94 };
95 
96 /* per-cpu kprobe control block */
97 struct kprobe_ctlblk {
98 	unsigned long kprobe_status;
99 	unsigned long kprobe_old_flags;
100 	unsigned long kprobe_saved_flags;
101 	struct prev_kprobe prev_kprobe;
102 };
103 
104 extern int kprobe_fault_handler(struct pt_regs *regs, int trapnr);
105 extern int kprobe_exceptions_notify(struct notifier_block *self,
106 				    unsigned long val, void *data);
107 extern int kprobe_int3_handler(struct pt_regs *regs);
108 extern int kprobe_debug_handler(struct pt_regs *regs);
109 
110 #endif /* CONFIG_KPROBES */
111 #endif /* _ASM_X86_KPROBES_H */
112