Home | History | Annotate | Line # | Download | only in include
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