1 /*-
2 * Mach Operating System
3 * Copyright (c) 1991,1990 Carnegie Mellon University
4 * All Rights Reserved.
5 *
6 * Permission to use, copy, modify and distribute this software and its
7 * documentation is hereby granted, provided that both the copyright
8 * notice and this permission notice appear in all copies of the
9 * software, derivative works or modified versions, and any portions
10 * thereof, and that both notices appear in supporting documentation.
11 *
12 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS
13 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
14 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
15 *
16 * Carnegie Mellon requests users of this software to return to
17 *
18 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
19 * School of Computer Science
20 * Carnegie Mellon University
21 * Pittsburgh PA 15213-3890
22 *
23 * any improvements or extensions that they make and grant Carnegie the
24 * rights to redistribute these changes.
25 */
26
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD: releng/11.2/sys/i386/i386/db_interface.c 308418 2016-11-07 12:10:17Z kib $");
29
30 /*
31 * Interface to new debugger.
32 */
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/cons.h>
36 #include <sys/kdb.h>
37 #include <sys/pcpu.h>
38 #include <sys/proc.h>
39
40 #include <machine/cpu.h>
41
42 #include <vm/vm.h>
43 #include <vm/pmap.h>
44
45 #include <ddb/ddb.h>
46
47 /*
48 * Read bytes from kernel address space for debugger.
49 */
50 int
51 db_read_bytes(vm_offset_t addr, size_t size, char *data)
52 {
53 jmp_buf jb;
54 void *prev_jb;
55 char *src;
56 int ret;
57
58 prev_jb = kdb_jmpbuf(jb);
59 ret = setjmp(jb);
60 if (ret == 0) {
61 src = (char *)addr;
62 while (size-- > 0)
63 *data++ = *src++;
64 }
65 (void)kdb_jmpbuf(prev_jb);
66 return (ret);
67 }
68
69 /*
70 * Write bytes to kernel address space for debugger.
71 */
72 int
73 db_write_bytes(vm_offset_t addr, size_t size, char *data)
74 {
75 jmp_buf jb;
76 void *prev_jb;
77 char *dst;
78 pt_entry_t *ptep0 = NULL;
79 pt_entry_t oldmap0 = 0;
80 vm_offset_t addr1;
81 pt_entry_t *ptep1 = NULL;
82 pt_entry_t oldmap1 = 0;
83 int ret;
84
85 prev_jb = kdb_jmpbuf(jb);
86 ret = setjmp(jb);
87 if (ret == 0) {
88 if (addr > trunc_page((vm_offset_t)btext) - size &&
89 addr < round_page((vm_offset_t)etext)) {
90
91 ptep0 = pmap_pte(kernel_pmap, addr);
92 oldmap0 = *ptep0;
93 *ptep0 |= PG_RW;
94
95 /*
96 * Map another page if the data crosses a page
97 * boundary.
98 */
99 if ((*ptep0 & PG_PS) == 0) {
100 addr1 = trunc_page(addr + size - 1);
101 if (trunc_page(addr) != addr1) {
102 ptep1 = pmap_pte(kernel_pmap, addr1);
103 oldmap1 = *ptep1;
104 *ptep1 |= PG_RW;
105 }
106 } else {
107 addr1 = trunc_4mpage(addr + size - 1);
108 if (trunc_4mpage(addr) != addr1) {
109 ptep1 = pmap_pte(kernel_pmap, addr1);
110 oldmap1 = *ptep1;
111 *ptep1 |= PG_RW;
112 }
113 }
114
115 invltlb();
116 }
117
118 dst = (char *)addr;
119
120 while (size-- > 0)
121 *dst++ = *data++;
122 }
123
124 (void)kdb_jmpbuf(prev_jb);
125
126 if (ptep0) {
127 *ptep0 = oldmap0;
128
129 if (ptep1)
130 *ptep1 = oldmap1;
131
132 invltlb();
133 }
134
135 return (ret);
136 }
137
138 int
139 db_segsize(struct trapframe *tfp)
140 {
141 struct proc_ldt *plp;
142 struct segment_descriptor *sdp;
143 int sel;
144
145 if (tfp == NULL)
146 return (32);
147 if (tfp->tf_eflags & PSL_VM)
148 return (16);
149 sel = tfp->tf_cs & 0xffff;
150 if (sel == GSEL(GCODE_SEL, SEL_KPL))
151 return (32);
152 /* Rare cases follow. User mode cases are currently unreachable. */
153 if (ISLDT(sel)) {
154 plp = curthread->td_proc->p_md.md_ldt;
155 sdp = (plp != NULL) ? &plp->ldt_sd : &ldt[0].sd;
156 } else {
157 sdp = &gdt[PCPU_GET(cpuid) * NGDT].sd;
158 }
159 return (sdp[IDXSEL(sel)].sd_def32 == 0 ? 16 : 32);
160 }
161
162 void
163 db_show_mdpcpu(struct pcpu *pc)
164 {
165
166 db_printf("APIC ID = %d\n", pc->pc_apic_id);
167 db_printf("currentldt = 0x%x\n", pc->pc_currentldt);
168 }
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