xref: /linux/arch/x86/include/asm/kprobes.h (revision 6ebe6dbd6886af07b102aca42e44edbee94a22d9)
1 #ifndef _ASM_X86_KPROBES_H
2 #define _ASM_X86_KPROBES_H
3 /*
4  *  Kernel Probes (KProbes)
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software
18  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
19  *
20  * Copyright (C) IBM Corporation, 2002, 2004
21  *
22  * See arch/x86/kernel/kprobes.c for x86 kprobes history.
23  */
24 
25 #include <asm-generic/kprobes.h>
26 
27 #define BREAKPOINT_INSTRUCTION	0xcc
28 
29 #ifdef CONFIG_KPROBES
30 #include <linux/types.h>
31 #include <linux/ptrace.h>
32 #include <linux/percpu.h>
33 #include <asm/insn.h>
34 
35 #define  __ARCH_WANT_KPROBES_INSN_SLOT
36 
37 struct pt_regs;
38 struct kprobe;
39 
40 typedef u8 kprobe_opcode_t;
41 #define RELATIVEJUMP_OPCODE 0xe9
42 #define RELATIVEJUMP_SIZE 5
43 #define RELATIVECALL_OPCODE 0xe8
44 #define RELATIVE_ADDR_SIZE 4
45 #define MAX_STACK_SIZE 64
46 #define CUR_STACK_SIZE(ADDR) \
47 	(current_top_of_stack() - (unsigned long)(ADDR))
48 #define MIN_STACK_SIZE(ADDR)				\
49 	(MAX_STACK_SIZE < CUR_STACK_SIZE(ADDR) ?	\
50 	 MAX_STACK_SIZE : CUR_STACK_SIZE(ADDR))
51 
52 #define flush_insn_slot(p)	do { } while (0)
53 
54 /* optinsn template addresses */
55 extern __visible kprobe_opcode_t optprobe_template_entry[];
56 extern __visible kprobe_opcode_t optprobe_template_val[];
57 extern __visible kprobe_opcode_t optprobe_template_call[];
58 extern __visible kprobe_opcode_t optprobe_template_end[];
59 #define MAX_OPTIMIZED_LENGTH (MAX_INSN_SIZE + RELATIVE_ADDR_SIZE)
60 #define MAX_OPTINSN_SIZE 				\
61 	(((unsigned long)optprobe_template_end -	\
62 	  (unsigned long)optprobe_template_entry) +	\
63 	 MAX_OPTIMIZED_LENGTH + RELATIVEJUMP_SIZE)
64 
65 extern const int kretprobe_blacklist_size;
66 
67 void arch_remove_kprobe(struct kprobe *p);
68 asmlinkage void kretprobe_trampoline(void);
69 
70 #ifdef CONFIG_KPROBES_ON_FTRACE
71 extern void arch_ftrace_kprobe_override_function(struct pt_regs *regs);
72 #endif
73 
74 /* Architecture specific copy of original instruction*/
75 struct arch_specific_insn {
76 	/* copy of the original instruction */
77 	kprobe_opcode_t *insn;
78 	/*
79 	 * boostable = false: This instruction type is not boostable.
80 	 * boostable = true: This instruction has been boosted: we have
81 	 * added a relative jump after the instruction copy in insn,
82 	 * so no single-step and fixup are needed (unless there's
83 	 * a post_handler or break_handler).
84 	 */
85 	bool boostable;
86 	bool if_modifier;
87 };
88 
89 struct arch_optimized_insn {
90 	/* copy of the original instructions */
91 	kprobe_opcode_t copied_insn[RELATIVE_ADDR_SIZE];
92 	/* detour code buffer */
93 	kprobe_opcode_t *insn;
94 	/* the size of instructions copied to detour code buffer */
95 	size_t size;
96 };
97 
98 /* Return true (!0) if optinsn is prepared for optimization. */
99 static inline int arch_prepared_optinsn(struct arch_optimized_insn *optinsn)
100 {
101 	return optinsn->size;
102 }
103 
104 struct prev_kprobe {
105 	struct kprobe *kp;
106 	unsigned long status;
107 	unsigned long old_flags;
108 	unsigned long saved_flags;
109 };
110 
111 /* per-cpu kprobe control block */
112 struct kprobe_ctlblk {
113 	unsigned long kprobe_status;
114 	unsigned long kprobe_old_flags;
115 	unsigned long kprobe_saved_flags;
116 	unsigned long *jprobe_saved_sp;
117 	struct pt_regs jprobe_saved_regs;
118 	kprobe_opcode_t jprobes_stack[MAX_STACK_SIZE];
119 	struct prev_kprobe prev_kprobe;
120 };
121 
122 extern int kprobe_fault_handler(struct pt_regs *regs, int trapnr);
123 extern int kprobe_exceptions_notify(struct notifier_block *self,
124 				    unsigned long val, void *data);
125 extern int kprobe_int3_handler(struct pt_regs *regs);
126 extern int kprobe_debug_handler(struct pt_regs *regs);
127 
128 #endif /* CONFIG_KPROBES */
129 #endif /* _ASM_X86_KPROBES_H */
130