1/*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2004 Marcel Moolenaar
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 *
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29#include <sys/param.h>
30#include <sys/systm.h>
31#include <sys/kdb.h>
32#include <sys/kernel.h>
33#include <sys/proc.h>
34#include <sys/reg.h>
35#include <sys/signal.h>
36
37#include <machine/endian.h>
38#include <machine/frame.h>
39#include <machine/gdb_machdep.h>
40#include <machine/pcb.h>
41#include <machine/trap.h>
42
43#include <gdb/gdb.h>
44#include <gdb/gdb_int.h>
45
46void *
47gdb_cpu_getreg(int regnum, size_t *regsz)
48{
49	static uint32_t _kcodesel = GSEL(GCODE_SEL, SEL_KPL);
50	static uint32_t _kdatasel = GSEL(GDATA_SEL, SEL_KPL);
51	static uint32_t _kprivsel = GSEL(GPRIV_SEL, SEL_KPL);
52
53	*regsz = gdb_cpu_regsz(regnum);
54
55	if (kdb_thread == curthread) {
56		switch (regnum) {
57		case 0:	return (&kdb_frame->tf_eax);
58		case 1:	return (&kdb_frame->tf_ecx);
59		case 2:	return (&kdb_frame->tf_edx);
60		case 9: return (&kdb_frame->tf_eflags);
61		case 10: return (&kdb_frame->tf_cs);
62		case 12: return (&kdb_frame->tf_ds);
63		case 13: return (&kdb_frame->tf_es);
64		case 14: return (&kdb_frame->tf_fs);
65		}
66	}
67	switch (regnum) {
68	case 3:  return (&kdb_thrctx->pcb_ebx);
69	case 4:  return (&kdb_thrctx->pcb_esp);
70	case 5:  return (&kdb_thrctx->pcb_ebp);
71	case 6:  return (&kdb_thrctx->pcb_esi);
72	case 7:  return (&kdb_thrctx->pcb_edi);
73	case 8:  return (&kdb_thrctx->pcb_eip);
74	case 10: return (&_kcodesel);
75	case 11: return (&_kdatasel);
76	case 12: return (&_kdatasel);
77	case 13: return (&_kdatasel);
78	case 14: return (&_kprivsel);
79	case 15: return (&kdb_thrctx->pcb_gs);
80	}
81	return (NULL);
82}
83
84void
85gdb_cpu_setreg(int regnum, void *val)
86{
87
88	switch (regnum) {
89	case GDB_REG_PC:
90		kdb_thrctx->pcb_eip = *(register_t *)val;
91		if (kdb_thread  == curthread)
92			kdb_frame->tf_eip = *(register_t *)val;
93	}
94}
95
96int
97gdb_cpu_signal(int type, int code)
98{
99
100	switch (type) {
101	case T_BPTFLT: return (SIGTRAP);
102	case T_ARITHTRAP: return (SIGFPE);
103	case T_PROTFLT: return (SIGSEGV);
104	case T_TRCTRAP: return (SIGTRAP);
105	case T_PAGEFLT: return (SIGSEGV);
106	case T_DIVIDE: return (SIGFPE);
107	case T_NMI: return (SIGTRAP);
108	case T_FPOPFLT: return (SIGILL);
109	case T_TSSFLT: return (SIGSEGV);
110	case T_SEGNPFLT: return (SIGSEGV);
111	case T_STKFLT: return (SIGSEGV);
112	case T_XMMFLT: return (SIGFPE);
113	}
114	return (SIGEMT);
115}
116
117void
118gdb_cpu_stop_reason(int type, int code)
119{
120	uintmax_t val;
121
122	val = 0;
123	if (type == T_TRCTRAP) {
124		/* NB: 'code' contains the value of dr6 at the trap. */
125		if ((code & DBREG_DR6_B(0)) != 0) {
126			val = rdr0();
127		}
128		if ((code & DBREG_DR6_B(1)) != 0) {
129			val = rdr1();
130		}
131		if ((code & DBREG_DR6_B(2)) != 0) {
132			val = rdr2();
133		}
134		if ((code & DBREG_DR6_B(3)) != 0) {
135			val = rdr3();
136		}
137
138		/*
139		 * TODO: validate the bits in DR7 to differentiate between a
140		 * watchpoint trap and a hardware breakpoint trap (currently
141		 * unsupported).
142		 */
143		if (val != 0) {
144			gdb_tx_str("watch:");
145			gdb_tx_varhex(val);
146			gdb_tx_char(';');
147		}
148	}
149}
150