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
31struct pt_regs;
32struct kprobe;
33
34typedef 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 */
51extern __visible kprobe_opcode_t optprobe_template_entry;
52extern __visible kprobe_opcode_t optprobe_template_val;
53extern __visible kprobe_opcode_t optprobe_template_call;
54extern __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
61extern const int kretprobe_blacklist_size;
62
63void arch_remove_kprobe(struct kprobe *p);
64asmlinkage void kretprobe_trampoline(void);
65
66/* Architecture specific copy of original instruction*/
67struct 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
82struct 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. */
92static inline int arch_prepared_optinsn(struct arch_optimized_insn *optinsn)
93{
94	return optinsn->size;
95}
96
97struct 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 */
105struct 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
115extern int kprobe_fault_handler(struct pt_regs *regs, int trapnr);
116extern int kprobe_exceptions_notify(struct notifier_block *self,
117				    unsigned long val, void *data);
118extern int kprobe_int3_handler(struct pt_regs *regs);
119extern int kprobe_debug_handler(struct pt_regs *regs);
120#endif /* _ASM_X86_KPROBES_H */
121