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
46 void *
gdb_cpu_getreg(int regnum,size_t * regsz)47 gdb_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
84 void
gdb_cpu_setreg(int regnum,void * val)85 gdb_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
96 int
gdb_cpu_signal(int type,int code)97 gdb_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
117 void
gdb_cpu_stop_reason(int type,int code)118 gdb_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