xref: /freebsd/sys/amd64/amd64/gdb_machdep.c (revision a0409676120c1e558d0ade943019934e0f15118d)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/kdb.h>
35 #include <sys/kernel.h>
36 #include <sys/proc.h>
37 #include <sys/signal.h>
38 
39 #include <machine/cpufunc.h>
40 #include <machine/frame.h>
41 #include <machine/gdb_machdep.h>
42 #include <machine/md_var.h>
43 #include <machine/pcb.h>
44 #include <machine/psl.h>
45 #include <machine/reg.h>
46 #include <machine/specialreg.h>
47 #include <machine/trap.h>
48 #include <machine/frame.h>
49 #include <machine/endian.h>
50 
51 #include <gdb/gdb.h>
52 
53 void *
54 gdb_cpu_getreg(int regnum, size_t *regsz)
55 {
56 	static uint32_t _kcodesel = GSEL(GCODE_SEL, SEL_KPL);
57 	static uint32_t _kdatasel = GSEL(GDATA_SEL, SEL_KPL);
58 
59 	*regsz = gdb_cpu_regsz(regnum);
60 
61 	if (kdb_thread  == curthread) {
62 		switch (regnum) {
63 		case GDB_REG_RAX: return (&kdb_frame->tf_rax);
64 		case GDB_REG_RCX: return (&kdb_frame->tf_rcx);
65 		case GDB_REG_RDX: return (&kdb_frame->tf_rdx);
66 		case GDB_REG_RSI: return (&kdb_frame->tf_rsi);
67 		case GDB_REG_RDI: return (&kdb_frame->tf_rdi);
68 		case GDB_REG_R8:  return (&kdb_frame->tf_r8);
69 		case GDB_REG_R9:  return (&kdb_frame->tf_r9);
70 		case GDB_REG_R10: return (&kdb_frame->tf_r10);
71 		case GDB_REG_R11: return (&kdb_frame->tf_r11);
72 		case GDB_REG_RFLAGS: return (&kdb_frame->tf_rflags);
73 		case GDB_REG_CS:  return (&kdb_frame->tf_cs);
74 		case GDB_REG_SS:  return (&kdb_frame->tf_ss);
75 		}
76 	}
77 	switch (regnum) {
78 	case GDB_REG_RBX: return (&kdb_thrctx->pcb_rbx);
79 	case GDB_REG_RBP: return (&kdb_thrctx->pcb_rbp);
80 	case GDB_REG_RSP: return (&kdb_thrctx->pcb_rsp);
81 	case GDB_REG_R12: return (&kdb_thrctx->pcb_r12);
82 	case GDB_REG_R13: return (&kdb_thrctx->pcb_r13);
83 	case GDB_REG_R14: return (&kdb_thrctx->pcb_r14);
84 	case GDB_REG_R15: return (&kdb_thrctx->pcb_r15);
85 	case GDB_REG_PC:  return (&kdb_thrctx->pcb_rip);
86 	case GDB_REG_CS:  return (&_kcodesel);
87 	case GDB_REG_SS:  return (&_kdatasel);
88 	}
89 	return (NULL);
90 }
91 
92 void
93 gdb_cpu_setreg(int regnum, void *val)
94 {
95 	register_t regval = *(register_t *)val;
96 
97 	/*
98 	 * Write registers to the trapframe and pcb, if applicable.
99 	 * Some scratch registers are not tracked by the pcb.
100 	 */
101 	if (kdb_thread == curthread) {
102 		switch (regnum) {
103 		case GDB_REG_RAX: kdb_frame->tf_rax = regval; break;
104 		case GDB_REG_RBX: kdb_frame->tf_rbx = regval; break;
105 		case GDB_REG_RCX: kdb_frame->tf_rcx = regval; break;
106 		case GDB_REG_RDX: kdb_frame->tf_rdx = regval; break;
107 		case GDB_REG_RSI: kdb_frame->tf_rsi = regval; break;
108 		case GDB_REG_RDI: kdb_frame->tf_rdi = regval; break;
109 		case GDB_REG_RBP: kdb_frame->tf_rbp = regval; break;
110 		case GDB_REG_RSP: kdb_frame->tf_rsp = regval; break;
111 		case GDB_REG_R8:  kdb_frame->tf_r8  = regval; break;
112 		case GDB_REG_R9:  kdb_frame->tf_r9  = regval; break;
113 		case GDB_REG_R10: kdb_frame->tf_r10 = regval; break;
114 		case GDB_REG_R11: kdb_frame->tf_r11 = regval; break;
115 		case GDB_REG_R12: kdb_frame->tf_r12 = regval; break;
116 		case GDB_REG_R13: kdb_frame->tf_r13 = regval; break;
117 		case GDB_REG_R14: kdb_frame->tf_r14 = regval; break;
118 		case GDB_REG_R15: kdb_frame->tf_r15 = regval; break;
119 		case GDB_REG_PC:  kdb_frame->tf_rip = regval; break;
120 		}
121 	}
122 	switch (regnum) {
123 	case GDB_REG_RBX: kdb_thrctx->pcb_rbx = regval; break;
124 	case GDB_REG_RBP: kdb_thrctx->pcb_rbp = regval; break;
125 	case GDB_REG_RSP: kdb_thrctx->pcb_rsp = regval; break;
126 	case GDB_REG_R12: kdb_thrctx->pcb_r12 = regval; break;
127 	case GDB_REG_R13: kdb_thrctx->pcb_r13 = regval; break;
128 	case GDB_REG_R14: kdb_thrctx->pcb_r14 = regval; break;
129 	case GDB_REG_R15: kdb_thrctx->pcb_r15 = regval; break;
130 	case GDB_REG_PC:  kdb_thrctx->pcb_rip = regval; break;
131 	}
132 }
133 
134 int
135 gdb_cpu_signal(int type, int code)
136 {
137 
138 	switch (type & ~T_USER) {
139 	case T_BPTFLT: return (SIGTRAP);
140 	case T_ARITHTRAP: return (SIGFPE);
141 	case T_PROTFLT: return (SIGSEGV);
142 	case T_TRCTRAP: return (SIGTRAP);
143 	case T_PAGEFLT: return (SIGSEGV);
144 	case T_DIVIDE: return (SIGFPE);
145 	case T_NMI: return (SIGTRAP);
146 	case T_FPOPFLT: return (SIGILL);
147 	case T_TSSFLT: return (SIGSEGV);
148 	case T_SEGNPFLT: return (SIGSEGV);
149 	case T_STKFLT: return (SIGSEGV);
150 	case T_XMMFLT: return (SIGFPE);
151 	}
152 	return (SIGEMT);
153 }
154 
155 void *
156 gdb_begin_write(void)
157 {
158 
159 	return (disable_wp() ? &gdb_begin_write : NULL);
160 }
161 
162 void
163 gdb_end_write(void *arg)
164 {
165 
166 	restore_wp(arg != NULL);
167 }
168