dbregs.h revision 1.4 1 /* $NetBSD: dbregs.h,v 1.4 2017/02/23 03:34:22 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 #include <sys/param.h>
34 #include <sys/types.h>
35 #include <machine/reg.h>
36
37 /*
38 * CPU Debug Status Register (DR6)
39 *
40 * Reserved bits: 4-12 and on x86_64 32-64
41 */
42 #define X86_DR6_DR0_BREAKPOINT_CONDITION_DETECTED __BIT(0)
43 #define X86_DR6_DR1_BREAKPOINT_CONDITION_DETECTED __BIT(1)
44 #define X86_DR6_DR2_BREAKPOINT_CONDITION_DETECTED __BIT(2)
45 #define X86_DR6_DR3_BREAKPOINT_CONDITION_DETECTED __BIT(3)
46 #define X86_DR6_DEBUG_REGISTER_ACCESS_DETECTED __BIT(13)
47 #define X86_DR6_SINGLE_STEP __BIT(14)
48 #define X86_DR6_TASK_SWITCH __BIT(15)
49
50 /*
51 * CPU Debug Control Register (DR7)
52 *
53 * LOCAL_EXACT_BREAKPOINT and GLOBAL_EXACT_BREAKPOINT are no longer used since
54 * the P6 processor family - portable code should set these bits
55 * unconditionally in oder to get exact breakpoints
56 *
57 * Reserved bits: 10, 12, 14-15 and on x86_64 32-64
58 */
59 #define X86_DR7_LOCAL_DR0_BREAKPOINT __BIT(0)
60 #define X86_DR7_GLOBAL_DR0_BREAKPOINT __BIT(1)
61 #define X86_DR7_LOCAL_DR1_BREAKPOINT __BIT(2)
62 #define X86_DR7_GLOBAL_DR1_BREAKPOINT __BIT(3)
63 #define X86_DR7_LOCAL_DR2_BREAKPOINT __BIT(4)
64 #define X86_DR7_GLOBAL_DR2_BREAKPOINT __BIT(5)
65 #define X86_DR7_LOCAL_DR3_BREAKPOINT __BIT(6)
66 #define X86_DR7_GLOBAL_DR3_BREAKPOINT __BIT(7)
67 #define X86_DR7_LOCAL_EXACT_BREAKPOINT __BIT(8)
68 #define X86_DR7_GLOBAL_EXACT_BREAKPOINT __BIT(9)
69 #define X86_DR7_RESTRICTED_TRANSACTIONAL_MEMORY __BIT(11)
70 #define X86_DR7_GENERAL_DETECT_ENABLE __BIT(13)
71
72 #define X86_DR7_DR0_CONDITION_MASK __BITS(16, 17)
73 #define X86_DR7_DR0_LENGTH_MASK __BITS(18, 19)
74 #define X86_DR7_DR1_CONDITION_MASK __BITS(20, 21)
75 #define X86_DR7_DR1_LENGTH_MASK __BITS(22, 23)
76 #define X86_DR7_DR2_CONDITION_MASK __BITS(24, 25)
77 #define X86_DR7_DR2_LENGTH_MASK __BITS(26, 27)
78 #define X86_DR7_DR3_CONDITION_MASK __BITS(28, 29)
79 #define X86_DR7_DR3_LENGTH_MASK __BITS(30, 31)
80
81 /*
82 * X86_DR7_CONDITION_IO_READWRITE is currently unused
83 * it requires DE (debug extension) flag in control register CR4 set
84 * not all CPUs support it
85 */
86 enum x86_dr7_condition {
87 X86_DR7_CONDITION_EXECUTION = 0x0,
88 X86_DR7_CONDITION_DATA_WRITE = 0x1,
89 X86_DR7_CONDITION_IO_READWRITE = 0x2,
90 X86_DR7_CONDITION_DATA_READWRITE = 0x3
91 };
92
93 /*
94 * 0x2 is currently unimplemented - it reflects 8 bytes on modern CPUs
95 */
96 enum x86_dr7_length {
97 X86_DR7_LENGTH_BYTE = 0x0,
98 X86_DR7_LENGTH_TWOBYTES = 0x1,
99 /* 0x2 undefined */
100 X86_DR7_LENGTH_FOURBYTES = 0x3
101 };
102
103 /*
104 * The number of available watchpoint/breakpoint registers available since
105 * Intel 80386. New CPUs (x86_64) ship with up to 16 Debug Registers but they
106 * still offer the same number of watchpoints/breakpoints.
107 */
108 #define X86_DBREGS 4
109
110 /*
111 * Store the initial Debug Register state of CPU
112 * This copy will be used to initialize new debug register state
113 */
114 void x86_dbregs_setup_initdbstate(void);
115
116 /*
117 * Reset CPU Debug Registers - to be used after returning to user context
118 */
119 void x86_dbregs_clear(struct lwp *l);
120
121 /*
122 * Retrieve Debug Registers from LWP's PCB and save in regs
123 * In case of empty register set, initialize it
124 */
125 void x86_dbregs_read(struct lwp *l, struct dbreg *regs);
126
127 /*
128 * Set CPU Debug Registers - to be used before entering user-land context
129 */
130 void x86_dbregs_set(struct lwp *l);
131
132 /*
133 * Store DR6 in LWP - to be used in trap function
134 */
135 void x86_dbregs_store_dr6(struct lwp *l);
136
137 /*
138 * Check if trap is triggered from user-land if so return nonzero value
139 */
140 int x86_dbregs_user_trap(void);
141
142 /*
143 * Check if trap is triggered from user-land if so return nonzero value
144 */
145 int x86_dbregs_validate(const struct dbreg *regs);
146
147 /*
148 * Write new Debug Registers from regs into LWP's PCB
149 */
150 void x86_dbregs_write(struct lwp *l, const struct dbreg *regs);
151
152 #endif /* !_X86_DBREGS_H_ */
153