xref: /freebsd/sys/amd64/include/db_machdep.h (revision 273c26a3c3bea87a241d6879abd4f991db180bf0)
1 /*-
2  * Mach Operating System
3  * Copyright (c) 1991,1990 Carnegie Mellon University
4  * All Rights Reserved.
5  *
6  * Permission to use, copy, modify and distribute this software and its
7  * documentation is hereby granted, provided that both the copyright
8  * notice and this permission notice appear in all copies of the
9  * software, derivative works or modified versions, and any portions
10  * thereof, and that both notices appear in supporting documentation.
11  *
12  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
13  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
14  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
15  *
16  * Carnegie Mellon requests users of this software to return to
17  *
18  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
19  *  School of Computer Science
20  *  Carnegie Mellon University
21  *  Pittsburgh PA 15213-3890
22  *
23  * any improvements or extensions that they make and grant Carnegie Mellon
24  * the rights to redistribute these changes.
25  *
26  * $FreeBSD$
27  */
28 
29 #ifndef _MACHINE_DB_MACHDEP_H_
30 #define	_MACHINE_DB_MACHDEP_H_
31 
32 #include <machine/frame.h>
33 #include <machine/trap.h>
34 
35 typedef	vm_offset_t	db_addr_t;	/* address - unsigned */
36 typedef	long		db_expr_t;	/* expression - signed */
37 
38 #define	PC_REGS()	((db_addr_t)kdb_thrctx->pcb_rip)
39 
40 #define	BKPT_INST	0xcc		/* breakpoint instruction */
41 #define	BKPT_SIZE	(1)		/* size of breakpoint inst */
42 #define	BKPT_SET(inst)	(BKPT_INST)
43 
44 #define BKPT_SKIP				\
45 do {						\
46 	kdb_frame->tf_rip += 1;			\
47 	kdb_thrctx->pcb_rip += 1;		\
48 } while(0)
49 
50 #define	FIXUP_PC_AFTER_BREAK			\
51 do {						\
52 	kdb_frame->tf_rip -= 1;			\
53 	kdb_thrctx->pcb_rip -= 1;		\
54 } while(0);
55 
56 #define	db_clear_single_step	kdb_cpu_clear_singlestep
57 #define	db_set_single_step	kdb_cpu_set_singlestep
58 
59 /*
60  * The debug exception type is copied from %dr6 to 'code' and used to
61  * disambiguate single step traps.  Watchpoints have no special support.
62  * Our hardware breakpoints are not well integrated with ddb and are too
63  * different from watchpoints.  ddb treats them as unknown traps with
64  * unknown addresses and doesn't turn them off while it is running.
65  */
66 #define	IS_BREAKPOINT_TRAP(type, code)	((type) == T_BPTFLT)
67 #define	IS_SSTEP_TRAP(type, code)	((type) == T_TRCTRAP && (code) & 0x4000)
68 #define	IS_WATCHPOINT_TRAP(type, code)	0
69 
70 #define	I_CALL		0xe8
71 #define	I_CALLI		0xff
72 #define	i_calli(ins)	(((ins)&0xff) == I_CALLI && ((ins)&0x3800) == 0x1000)
73 #define	I_RET		0xc3
74 #define	I_IRET		0xcf
75 #define	i_rex(ins)	(((ins) & 0xff) == 0x41 || ((ins) & 0xff) == 0x43)
76 
77 #define	inst_trap_return(ins)	(((ins)&0xff) == I_IRET)
78 #define	inst_return(ins)	(((ins)&0xff) == I_RET)
79 #define	inst_call(ins)		(((ins)&0xff) == I_CALL || i_calli(ins) || \
80 				 (i_calli((ins) >> 8) && i_rex(ins)))
81 #define inst_load(ins)		0
82 #define inst_store(ins)		0
83 
84 /*
85  * There no interesting addresses below _kstack = 0xefbfe000.  There
86  * are small absolute values for GUPROF, but we don't want to see them.
87  * Treat "negative" addresses below _kstack as non-small to allow for
88  * future reductions of _kstack and to avoid sign extension problems.
89  *
90  * There is one interesting symbol above -db_maxoff = 0xffff0000,
91  * namely _APTD = 0xfffff000.  Accepting this would mess up the
92  * printing of small negative offsets.  The next largest symbol is
93  * _APTmap = 0xffc00000.  Accepting this is OK (unless db_maxoff is
94  * set to >= 0x400000 - (max stack offset)).
95  */
96 #define	DB_SMALL_VALUE_MAX	0x7fffffff
97 #define	DB_SMALL_VALUE_MIN	(-0x400001)
98 
99 #endif /* !_MACHINE_DB_MACHDEP_H_ */
100