xref: /freebsd/sys/amd64/amd64/gdb_machdep.c (revision 4f4b548b1d21ae16955b09f9b717524167a7d97e)
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 0:	return (&kdb_frame->tf_rax);
64 		case 2:	return (&kdb_frame->tf_rcx);
65 		case 3:	return (&kdb_frame->tf_rdx);
66 		case 4:	return (&kdb_frame->tf_rsi);
67 		case 5:	return (&kdb_frame->tf_rdi);
68 		case 8: return (&kdb_frame->tf_r8);
69 		case 9: return (&kdb_frame->tf_r9);
70 		case 10: return (&kdb_frame->tf_r10);
71 		case 11: return (&kdb_frame->tf_r11);
72 		case 17: return (&kdb_frame->tf_rflags);
73 		case 18: return (&kdb_frame->tf_cs);
74 		case 19: return (&kdb_frame->tf_ss);
75 		}
76 	}
77 	switch (regnum) {
78 	case 1:  return (&kdb_thrctx->pcb_rbx);
79 	case 6:  return (&kdb_thrctx->pcb_rbp);
80 	case 7:  return (&kdb_thrctx->pcb_rsp);
81 	case 12: return (&kdb_thrctx->pcb_r12);
82 	case 13: return (&kdb_thrctx->pcb_r13);
83 	case 14: return (&kdb_thrctx->pcb_r14);
84 	case 15: return (&kdb_thrctx->pcb_r15);
85 	case 16: return (&kdb_thrctx->pcb_rip);
86 	case 18: return (&_kcodesel);
87 	case 19: return (&_kdatasel);
88 	}
89 	return (NULL);
90 }
91 
92 void
93 gdb_cpu_setreg(int regnum, void *val)
94 {
95 
96 	switch (regnum) {
97 	case GDB_REG_PC:
98 		kdb_thrctx->pcb_rip = *(register_t *)val;
99 		if (kdb_thread  == curthread)
100 			kdb_frame->tf_rip = *(register_t *)val;
101 	}
102 }
103 
104 int
105 gdb_cpu_signal(int type, int code)
106 {
107 
108 	switch (type & ~T_USER) {
109 	case 0: return (SIGFPE);	/* Divide by zero. */
110 	case 1: return (SIGTRAP);	/* Debug exception. */
111 	case 3: return (SIGTRAP);	/* Breakpoint. */
112 	case 4: return (SIGSEGV);	/* into instr. (overflow). */
113 	case 5: return (SIGURG);	/* bound instruction. */
114 	case 6: return (SIGILL);	/* Invalid opcode. */
115 	case 7: return (SIGFPE);	/* Coprocessor not present. */
116 	case 8: return (SIGEMT);	/* Double fault. */
117 	case 9: return (SIGSEGV);	/* Coprocessor segment overrun. */
118 	case 10: return (SIGTRAP);	/* Invalid TSS (also single-step). */
119 	case 11: return (SIGSEGV);	/* Segment not present. */
120 	case 12: return (SIGSEGV);	/* Stack exception. */
121 	case 13: return (SIGSEGV);	/* General protection. */
122 	case 14: return (SIGSEGV);	/* Page fault. */
123 	case 16: return (SIGEMT);	/* Coprocessor error. */
124 	}
125 	return (SIGEMT);
126 }
127 
128 void *
129 gdb_begin_write(void)
130 {
131 
132 	return (disable_wp() ? &gdb_begin_write : NULL);
133 }
134 
135 void
136 gdb_end_write(void *arg)
137 {
138 
139 	restore_wp(arg != NULL);
140 }
141 
142