xref: /linux/arch/x86/include/asm/kprobes.h (revision f3a8b6645dc2e60d11f20c1c23afd964ff4e55ae)
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 #include <linux/types.h>
25 #include <linux/ptrace.h>
26 #include <linux/percpu.h>
27 #include <asm/insn.h>
28 
29 #define  __ARCH_WANT_KPROBES_INSN_SLOT
30 
31 struct pt_regs;
32 struct kprobe;
33 
34 typedef u8 kprobe_opcode_t;
35 #define BREAKPOINT_INSTRUCTION	0xcc
36 #define RELATIVEJUMP_OPCODE 0xe9
37 #define RELATIVEJUMP_SIZE 5
38 #define RELATIVECALL_OPCODE 0xe8
39 #define RELATIVE_ADDR_SIZE 4
40 #define MAX_STACK_SIZE 64
41 #define CUR_STACK_SIZE(ADDR) \
42 	(current_top_of_stack() - (unsigned long)(ADDR))
43 #define MIN_STACK_SIZE(ADDR)				\
44 	(MAX_STACK_SIZE < CUR_STACK_SIZE(ADDR) ?	\
45 	 MAX_STACK_SIZE : CUR_STACK_SIZE(ADDR))
46 
47 #define flush_insn_slot(p)	do { } while (0)
48 
49 /* optinsn template addresses */
50 extern __visible kprobe_opcode_t optprobe_template_entry;
51 extern __visible kprobe_opcode_t optprobe_template_val;
52 extern __visible kprobe_opcode_t optprobe_template_call;
53 extern __visible kprobe_opcode_t optprobe_template_end;
54 #define MAX_OPTIMIZED_LENGTH (MAX_INSN_SIZE + RELATIVE_ADDR_SIZE)
55 #define MAX_OPTINSN_SIZE 				\
56 	(((unsigned long)&optprobe_template_end -	\
57 	  (unsigned long)&optprobe_template_entry) +	\
58 	 MAX_OPTIMIZED_LENGTH + RELATIVEJUMP_SIZE)
59 
60 extern const int kretprobe_blacklist_size;
61 
62 void arch_remove_kprobe(struct kprobe *p);
63 asmlinkage void kretprobe_trampoline(void);
64 
65 /* Architecture specific copy of original instruction*/
66 struct arch_specific_insn {
67 	/* copy of the original instruction */
68 	kprobe_opcode_t *insn;
69 	/*
70 	 * boostable = -1: This instruction type is not boostable.
71 	 * boostable = 0: This instruction type is boostable.
72 	 * boostable = 1: This instruction has been boosted: we have
73 	 * added a relative jump after the instruction copy in insn,
74 	 * so no single-step and fixup are needed (unless there's
75 	 * a post_handler or break_handler).
76 	 */
77 	int boostable;
78 	bool if_modifier;
79 };
80 
81 struct arch_optimized_insn {
82 	/* copy of the original instructions */
83 	kprobe_opcode_t copied_insn[RELATIVE_ADDR_SIZE];
84 	/* detour code buffer */
85 	kprobe_opcode_t *insn;
86 	/* the size of instructions copied to detour code buffer */
87 	size_t size;
88 };
89 
90 /* Return true (!0) if optinsn is prepared for optimization. */
91 static inline int arch_prepared_optinsn(struct arch_optimized_insn *optinsn)
92 {
93 	return optinsn->size;
94 }
95 
96 struct prev_kprobe {
97 	struct kprobe *kp;
98 	unsigned long status;
99 	unsigned long old_flags;
100 	unsigned long saved_flags;
101 };
102 
103 /* per-cpu kprobe control block */
104 struct kprobe_ctlblk {
105 	unsigned long kprobe_status;
106 	unsigned long kprobe_old_flags;
107 	unsigned long kprobe_saved_flags;
108 	unsigned long *jprobe_saved_sp;
109 	struct pt_regs jprobe_saved_regs;
110 	kprobe_opcode_t jprobes_stack[MAX_STACK_SIZE];
111 	struct prev_kprobe prev_kprobe;
112 };
113 
114 extern int kprobe_fault_handler(struct pt_regs *regs, int trapnr);
115 extern int kprobe_exceptions_notify(struct notifier_block *self,
116 				    unsigned long val, void *data);
117 extern int kprobe_int3_handler(struct pt_regs *regs);
118 extern int kprobe_debug_handler(struct pt_regs *regs);
119 #endif /* _ASM_X86_KPROBES_H */
120