dbregs.h revision 1.3
1/*	$NetBSD: dbregs.h,v 1.3 2017/01/18 05:12:00 kamil Exp $	*/
2
3/*-
4 * Copyright (c) 2016 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
17 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
18 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
19 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
20 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26 * POSSIBILITY OF SUCH DAMAGE.
27 */
28
29
30#ifndef	_X86_DBREGS_H_
31#define	_X86_DBREGS_H_
32
33#if defined(_KERNEL)
34
35#include <sys/param.h>
36#include <sys/types.h>
37
38/*
39 * CPU Debug Status Register (DR6)
40 *
41 * Reserved bits: 4-12 and on x86_64 32-64
42 */
43#define X86_HW_WATCHPOINT_DR6_DR0_BREAKPOINT_CONDITION_DETECTED	__BIT(0)
44#define X86_HW_WATCHPOINT_DR6_DR1_BREAKPOINT_CONDITION_DETECTED	__BIT(1)
45#define X86_HW_WATCHPOINT_DR6_DR2_BREAKPOINT_CONDITION_DETECTED	__BIT(2)
46#define X86_HW_WATCHPOINT_DR6_DR3_BREAKPOINT_CONDITION_DETECTED	__BIT(3)
47#define X86_HW_WATCHPOINT_DR6_DEBUG_REGISTER_ACCESS_DETECTED	__BIT(13)
48#define X86_HW_WATCHPOINT_DR6_SINGLE_STEP			__BIT(14)
49#define X86_HW_WATCHPOINT_DR6_TASK_SWITCH			__BIT(15)
50
51/*
52 * CPU Debug Control Register (DR7)
53 *
54 * LOCAL_EXACT_BREAKPOINT and GLOBAL_EXACT_BREAKPOINT are no longer used since
55 * the P6 processor family - portable code should set these bits
56 * unconditionally in oder to get exact breakpoints
57 *
58 * Reserved bits: 10, 12, 14-15 and on x86_64 32-64
59 */
60#define X86_HW_WATCHPOINT_DR7_LOCAL_DR0_BREAKPOINT		__BIT(0)
61#define X86_HW_WATCHPOINT_DR7_GLOBAL_DR0_BREAKPOINT		__BIT(1)
62#define X86_HW_WATCHPOINT_DR7_LOCAL_DR1_BREAKPOINT		__BIT(2)
63#define X86_HW_WATCHPOINT_DR7_GLOBAL_DR1_BREAKPOINT		__BIT(3)
64#define X86_HW_WATCHPOINT_DR7_LOCAL_DR2_BREAKPOINT		__BIT(4)
65#define X86_HW_WATCHPOINT_DR7_GLOBAL_DR2_BREAKPOINT		__BIT(5)
66#define X86_HW_WATCHPOINT_DR7_LOCAL_DR3_BREAKPOINT		__BIT(6)
67#define X86_HW_WATCHPOINT_DR7_GLOBAL_DR3_BREAKPOINT		__BIT(7)
68#define X86_HW_WATCHPOINT_DR7_LOCAL_EXACT_BREAKPOINT		__BIT(8)
69#define X86_HW_WATCHPOINT_DR7_GLOBAL_EXACT_BREAKPOINT		__BIT(9)
70#define X86_HW_WATCHPOINT_DR7_RESTRICTED_TRANSACTIONAL_MEMORY	__BIT(11)
71#define X86_HW_WATCHPOINT_DR7_GENERAL_DETECT_ENABLE		__BIT(13)
72
73#define X86_HW_WATCHPOINT_DR7_DR0_CONDITION_MASK		__BITS(16, 17)
74#define X86_HW_WATCHPOINT_DR7_DR0_LENGTH_MASK			__BITS(18, 19)
75#define X86_HW_WATCHPOINT_DR7_DR1_CONDITION_MASK		__BITS(20, 21)
76#define X86_HW_WATCHPOINT_DR7_DR1_LENGTH_MASK			__BITS(22, 23)
77#define X86_HW_WATCHPOINT_DR7_DR2_CONDITION_MASK		__BITS(24, 25)
78#define X86_HW_WATCHPOINT_DR7_DR2_LENGTH_MASK			__BITS(26, 27)
79#define X86_HW_WATCHPOINT_DR7_DR3_CONDITION_MASK		__BITS(28, 29)
80#define X86_HW_WATCHPOINT_DR7_DR3_LENGTH_MASK			__BITS(30, 31)
81
82#endif /* !defined(_KERNEL) */
83
84/*
85 * X86_HW_WATCHPOINT_DR7_CONDITION_IO_READWRITE is currently unused
86 * it requires DE (debug extension) flag in control register CR4 set
87 * not all CPUs support it
88 */
89enum x86_hw_watchpoint_condition {
90	X86_HW_WATCHPOINT_DR7_CONDITION_EXECUTION	= 0x0,
91	X86_HW_WATCHPOINT_DR7_CONDITION_DATA_WRITE	= 0x1,
92	X86_HW_WATCHPOINT_DR7_CONDITION_IO_READWRITE	= 0x2,
93	X86_HW_WATCHPOINT_DR7_CONDITION_DATA_READWRITE	= 0x3
94};
95
96/*
97 * 0x2 is currently unimplemented - it reflects 8 bytes on modern CPUs
98 */
99enum x86_hw_watchpoint_length {
100	X86_HW_WATCHPOINT_DR7_LENGTH_BYTE	= 0x0,
101	X86_HW_WATCHPOINT_DR7_LENGTH_TWOBYTES	= 0x1,
102	/* 0x2 undefined */
103	X86_HW_WATCHPOINT_DR7_LENGTH_FOURBYTES	= 0x3
104};
105
106/*
107 * 0x2 is currently unimplemented - it reflects 8 bytes on modern CPUs
108 */
109enum x86_hw_watchpoint_event {
110	X86_HW_WATCHPOINT_EVENT_NONE		= 0x0,
111	X86_HW_WATCHPOINT_EVENT_FIRED		= 0x1,
112	X86_HW_WATCHPOINT_EVENT_FIRED_AND_SSTEP	= 0x2,
113};
114
115#if defined(_KMEMUSER) || defined(_KERNEL)
116
117/*
118 * The number of available watchpoint registers available since Intel 80386
119 * New CPUs ship with up to 16 Debug Registers but they still offer four
120 * watchpoints, while there other registers are reserved
121 */
122#define X86_HW_WATCHPOINTS	4
123
124/*
125 * lwpid - 0 means all LWPs in the process
126 * address - 0 means that watchpoint is disabled
127 */
128struct x86_hw_watchpoint {
129	vaddr_t	address;
130	enum x86_hw_watchpoint_condition condition;
131	enum x86_hw_watchpoint_length length;
132};
133
134#endif /* !defined(_KMEMUSER) && !defined(_KERNEL) */
135
136#if defined(_KERNEL)
137/*
138 * Set CPU Debug Registers - to be used before entering user-land context
139 */
140void set_x86_hw_watchpoints(struct lwp *l);
141
142/*
143 * Reset CPU Debug Registers - to be used after entering kernel context
144 */
145void clear_x86_hw_watchpoints(void);
146
147/*
148 * Check if trap is triggered from user-land if so return nonzero value
149 */
150int user_trap_x86_hw_watchpoint(void);
151
152/*
153 * Check if trap is triggered from user-land if so return nonzero value
154 */
155int x86_hw_watchpoint_type(int);
156
157/*
158 * Return register that fired
159 */
160int x86_hw_watchpoint_reg(int);
161
162#endif /* !defined(_KERNEL) */
163
164#endif /* !_X86_DBREGS_H_ */
165