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/cpufunc.h>
38 #include <machine/frame.h>
39 #include <machine/gdb_machdep.h>
40 #include <machine/md_var.h>
41 #include <machine/pcb.h>
42 #include <machine/psl.h>
43 #include <machine/specialreg.h>
44 #include <machine/trap.h>
45 #include <machine/frame.h>
46 #include <machine/endian.h>
47
48 #include <gdb/gdb.h>
49 #include <gdb/gdb_int.h>
50
51 void *
gdb_cpu_getreg(int regnum,size_t * regsz)52 gdb_cpu_getreg(int regnum, size_t *regsz)
53 {
54 static uint32_t _kcodesel = GSEL(GCODE_SEL, SEL_KPL);
55 static uint32_t _kdatasel = GSEL(GDATA_SEL, SEL_KPL);
56
57 *regsz = gdb_cpu_regsz(regnum);
58
59 if (kdb_thread == curthread) {
60 switch (regnum) {
61 case GDB_REG_RAX: return (&kdb_frame->tf_rax);
62 case GDB_REG_RCX: return (&kdb_frame->tf_rcx);
63 case GDB_REG_RDX: return (&kdb_frame->tf_rdx);
64 case GDB_REG_RSI: return (&kdb_frame->tf_rsi);
65 case GDB_REG_RDI: return (&kdb_frame->tf_rdi);
66 case GDB_REG_R8: return (&kdb_frame->tf_r8);
67 case GDB_REG_R9: return (&kdb_frame->tf_r9);
68 case GDB_REG_R10: return (&kdb_frame->tf_r10);
69 case GDB_REG_R11: return (&kdb_frame->tf_r11);
70 case GDB_REG_RFLAGS: return (&kdb_frame->tf_rflags);
71 case GDB_REG_CS: return (&kdb_frame->tf_cs);
72 case GDB_REG_SS: return (&kdb_frame->tf_ss);
73 }
74 }
75 switch (regnum) {
76 case GDB_REG_RBX: return (&kdb_thrctx->pcb_rbx);
77 case GDB_REG_RBP: return (&kdb_thrctx->pcb_rbp);
78 case GDB_REG_RSP: return (&kdb_thrctx->pcb_rsp);
79 case GDB_REG_R12: return (&kdb_thrctx->pcb_r12);
80 case GDB_REG_R13: return (&kdb_thrctx->pcb_r13);
81 case GDB_REG_R14: return (&kdb_thrctx->pcb_r14);
82 case GDB_REG_R15: return (&kdb_thrctx->pcb_r15);
83 case GDB_REG_PC: return (&kdb_thrctx->pcb_rip);
84 case GDB_REG_CS: return (&_kcodesel);
85 case GDB_REG_SS: return (&_kdatasel);
86 }
87 return (NULL);
88 }
89
90 void
gdb_cpu_setreg(int regnum,void * val)91 gdb_cpu_setreg(int regnum, void *val)
92 {
93 register_t regval = *(register_t *)val;
94
95 /*
96 * Write registers to the trapframe and pcb, if applicable.
97 * Some scratch registers are not tracked by the pcb.
98 */
99 if (kdb_thread == curthread) {
100 switch (regnum) {
101 case GDB_REG_RAX: kdb_frame->tf_rax = regval; break;
102 case GDB_REG_RBX: kdb_frame->tf_rbx = regval; break;
103 case GDB_REG_RCX: kdb_frame->tf_rcx = regval; break;
104 case GDB_REG_RDX: kdb_frame->tf_rdx = regval; break;
105 case GDB_REG_RSI: kdb_frame->tf_rsi = regval; break;
106 case GDB_REG_RDI: kdb_frame->tf_rdi = regval; break;
107 case GDB_REG_RBP: kdb_frame->tf_rbp = regval; break;
108 case GDB_REG_RSP: kdb_frame->tf_rsp = regval; break;
109 case GDB_REG_R8: kdb_frame->tf_r8 = regval; break;
110 case GDB_REG_R9: kdb_frame->tf_r9 = regval; break;
111 case GDB_REG_R10: kdb_frame->tf_r10 = regval; break;
112 case GDB_REG_R11: kdb_frame->tf_r11 = regval; break;
113 case GDB_REG_R12: kdb_frame->tf_r12 = regval; break;
114 case GDB_REG_R13: kdb_frame->tf_r13 = regval; break;
115 case GDB_REG_R14: kdb_frame->tf_r14 = regval; break;
116 case GDB_REG_R15: kdb_frame->tf_r15 = regval; break;
117 case GDB_REG_PC: kdb_frame->tf_rip = regval; break;
118 }
119 }
120 switch (regnum) {
121 case GDB_REG_RBX: kdb_thrctx->pcb_rbx = regval; break;
122 case GDB_REG_RBP: kdb_thrctx->pcb_rbp = regval; break;
123 case GDB_REG_RSP: kdb_thrctx->pcb_rsp = regval; break;
124 case GDB_REG_R12: kdb_thrctx->pcb_r12 = regval; break;
125 case GDB_REG_R13: kdb_thrctx->pcb_r13 = regval; break;
126 case GDB_REG_R14: kdb_thrctx->pcb_r14 = regval; break;
127 case GDB_REG_R15: kdb_thrctx->pcb_r15 = regval; break;
128 case GDB_REG_PC: kdb_thrctx->pcb_rip = regval; break;
129 }
130 }
131
132 int
gdb_cpu_signal(int type,int code)133 gdb_cpu_signal(int type, int code)
134 {
135
136 switch (type) {
137 case T_BPTFLT: return (SIGTRAP);
138 case T_ARITHTRAP: return (SIGFPE);
139 case T_PROTFLT: return (SIGSEGV);
140 case T_TRCTRAP: return (SIGTRAP);
141 case T_PAGEFLT: return (SIGSEGV);
142 case T_DIVIDE: return (SIGFPE);
143 case T_NMI: return (SIGTRAP);
144 case T_FPOPFLT: return (SIGILL);
145 case T_TSSFLT: return (SIGSEGV);
146 case T_SEGNPFLT: return (SIGSEGV);
147 case T_STKFLT: return (SIGSEGV);
148 case T_XMMFLT: return (SIGFPE);
149 }
150 return (SIGEMT);
151 }
152
153 void
gdb_cpu_stop_reason(int type,int code)154 gdb_cpu_stop_reason(int type, int code)
155 {
156 uintmax_t val;
157
158 val = 0;
159 if (type == T_TRCTRAP) {
160 /* NB: 'code' contains the value of dr6 at the trap. */
161 if ((code & DBREG_DR6_B(0)) != 0) {
162 val = rdr0();
163 }
164 if ((code & DBREG_DR6_B(1)) != 0) {
165 val = rdr1();
166 }
167 if ((code & DBREG_DR6_B(2)) != 0) {
168 val = rdr2();
169 }
170 if ((code & DBREG_DR6_B(3)) != 0) {
171 val = rdr3();
172 }
173
174 /*
175 * TODO: validate the bits in DR7 to differentiate between a
176 * watchpoint trap and a hardware breakpoint trap (currently
177 * unsupported).
178 */
179 if (val != 0) {
180 gdb_tx_str("watch:");
181 gdb_tx_varhex(val);
182 gdb_tx_char(';');
183 }
184 }
185 }
186
187 void *
gdb_begin_write(void)188 gdb_begin_write(void)
189 {
190
191 return (disable_wp() ? &gdb_begin_write : NULL);
192 }
193
194 void
gdb_end_write(void * arg)195 gdb_end_write(void *arg)
196 {
197
198 restore_wp(arg != NULL);
199 }
200