xref: /linux/arch/x86/include/asm/kprobes.h (revision 93d90ad708b8da6efc0e487b66111aa9db7f70c7)
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 MIN_STACK_SIZE(ADDR)					       \
42 	(((MAX_STACK_SIZE) < (((unsigned long)current_thread_info()) + \
43 			      THREAD_SIZE - (unsigned long)(ADDR)))    \
44 	 ? (MAX_STACK_SIZE)					       \
45 	 : (((unsigned long)current_thread_info()) +		       \
46 	    THREAD_SIZE - (unsigned long)(ADDR)))
47 
48 #define flush_insn_slot(p)	do { } while (0)
49 
50 /* optinsn template addresses */
51 extern __visible kprobe_opcode_t optprobe_template_entry;
52 extern __visible kprobe_opcode_t optprobe_template_val;
53 extern __visible kprobe_opcode_t optprobe_template_call;
54 extern __visible kprobe_opcode_t optprobe_template_end;
55 #define MAX_OPTIMIZED_LENGTH (MAX_INSN_SIZE + RELATIVE_ADDR_SIZE)
56 #define MAX_OPTINSN_SIZE 				\
57 	(((unsigned long)&optprobe_template_end -	\
58 	  (unsigned long)&optprobe_template_entry) +	\
59 	 MAX_OPTIMIZED_LENGTH + RELATIVEJUMP_SIZE)
60 
61 extern const int kretprobe_blacklist_size;
62 
63 void arch_remove_kprobe(struct kprobe *p);
64 asmlinkage void kretprobe_trampoline(void);
65 
66 /* Architecture specific copy of original instruction*/
67 struct arch_specific_insn {
68 	/* copy of the original instruction */
69 	kprobe_opcode_t *insn;
70 	/*
71 	 * boostable = -1: This instruction type is not boostable.
72 	 * boostable = 0: This instruction type is boostable.
73 	 * boostable = 1: This instruction has been boosted: we have
74 	 * added a relative jump after the instruction copy in insn,
75 	 * so no single-step and fixup are needed (unless there's
76 	 * a post_handler or break_handler).
77 	 */
78 	int boostable;
79 	bool if_modifier;
80 };
81 
82 struct arch_optimized_insn {
83 	/* copy of the original instructions */
84 	kprobe_opcode_t copied_insn[RELATIVE_ADDR_SIZE];
85 	/* detour code buffer */
86 	kprobe_opcode_t *insn;
87 	/* the size of instructions copied to detour code buffer */
88 	size_t size;
89 };
90 
91 /* Return true (!0) if optinsn is prepared for optimization. */
92 static inline int arch_prepared_optinsn(struct arch_optimized_insn *optinsn)
93 {
94 	return optinsn->size;
95 }
96 
97 struct prev_kprobe {
98 	struct kprobe *kp;
99 	unsigned long status;
100 	unsigned long old_flags;
101 	unsigned long saved_flags;
102 };
103 
104 /* per-cpu kprobe control block */
105 struct kprobe_ctlblk {
106 	unsigned long kprobe_status;
107 	unsigned long kprobe_old_flags;
108 	unsigned long kprobe_saved_flags;
109 	unsigned long *jprobe_saved_sp;
110 	struct pt_regs jprobe_saved_regs;
111 	kprobe_opcode_t jprobes_stack[MAX_STACK_SIZE];
112 	struct prev_kprobe prev_kprobe;
113 };
114 
115 extern int kprobe_fault_handler(struct pt_regs *regs, int trapnr);
116 extern int kprobe_exceptions_notify(struct notifier_block *self,
117 				    unsigned long val, void *data);
118 extern int kprobe_int3_handler(struct pt_regs *regs);
119 extern int kprobe_debug_handler(struct pt_regs *regs);
120 #endif /* _ASM_X86_KPROBES_H */
121