1 /* $OpenBSD: kvm_sh.c,v 1.9 2021/12/01 21:45:19 deraadt Exp $ */
2
3 /*
4 * Copyright (c) 2007 Miodrag Vallat.
5 *
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice, this permission notice, and the disclaimer below
9 * appear in all copies.
10 *
11 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
12 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
13 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
14 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
15 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
16 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
17 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18 */
19
20 #include <sys/types.h>
21 #include <sys/kcore.h>
22
23 #include <unistd.h>
24 #include <stdlib.h>
25 #include <nlist.h>
26 #include <kvm.h>
27
28 #include <db.h>
29
30 #include "kvm_private.h"
31
32 #include <machine/cpu.h>
33 #include <machine/kcore.h>
34 #include <machine/pte.h>
35 #include <machine/vmparam.h>
36
37 void
_kvm_freevtop(kvm_t * kd)38 _kvm_freevtop(kvm_t *kd)
39 {
40 }
41
42 int
_kvm_initvtop(kvm_t * kd)43 _kvm_initvtop(kvm_t *kd)
44 {
45 return (0);
46 }
47
48 /*
49 * Translate a kernel virtual address to a physical address by walking
50 * the kernel page tables.
51 */
52
53 /* Stolen from sys/arch/sh/include/pmap.h we can't really include */
54 #define __PMAP_PTP_N 512 /* # of page table page maps 2GB. */
55 /* Stolen from sys/arch/sh/sh/pmap.c */
56 #define __PMAP_PTP_SHIFT 22
57 #define __PMAP_PTP_PG_N (kd->nbpg / sizeof(pt_entry_t))
58 #define __PMAP_PTP_INDEX(va) (((va) >> __PMAP_PTP_SHIFT) & (__PMAP_PTP_N - 1))
59 #define __PMAP_PTP_OFSET(va) ((va / kd->nbpg) & (__PMAP_PTP_PG_N - 1))
60
61 int
_kvm_kvatop(kvm_t * kd,u_long va,paddr_t * pa)62 _kvm_kvatop(kvm_t *kd, u_long va, paddr_t *pa)
63 {
64 cpu_kcore_hdr_t *h = kd->cpu_data;
65 u_int l1idx, l2idx;
66 vaddr_t l2va;
67 pt_entry_t l1pte, l2pte;
68 off_t pteoffset;
69
70 if (ISALIVE(kd)) {
71 _kvm_err(kd, 0, "vatop called in live kernel!");
72 return (0);
73 }
74
75 /*
76 * P1 and P2 segments addresses are trivial.
77 */
78 if (va >= SH3_P1SEG_BASE && va <= SH3_P1SEG_END) {
79 *pa = SH3_P1SEG_TO_PHYS(va);
80 return (int)((vaddr_t)SH3_P1SEG_END + 1 - va);
81 }
82 if (va >= SH3_P2SEG_BASE && va <= SH3_P2SEG_END) {
83 *pa = SH3_P2SEG_TO_PHYS(va);
84 return (int)((vaddr_t)SH3_P2SEG_END + 1 - va);
85 }
86
87 /*
88 * P3 segment addresses need kernel page table walk.
89 */
90 if (va >= SH3_P3SEG_BASE && va < SH3_P3SEG_END) {
91 l1idx = __PMAP_PTP_INDEX(va - VM_MIN_KERNEL_ADDRESS);
92 l2idx = __PMAP_PTP_OFSET(va);
93
94 /* read level 1 pte */
95 pteoffset = h->kcore_kptp + sizeof(pt_entry_t) * l1idx;
96 if (_kvm_pread(kd, kd->pmfd, (char *)&l1pte, sizeof(l1pte),
97 _kvm_pa2off(kd, pteoffset)) != sizeof(l1pte)) {
98 _kvm_syserr(kd, 0, "could not read level 1 pte");
99 goto bad;
100 }
101
102 /* check pte for validity */
103 if ((l1pte & PG_V) == 0) {
104 _kvm_err(kd, 0, "invalid level 1 pte: no valid bit");
105 goto bad;
106 }
107
108 l2va = l1pte & PG_PPN;
109 if (l2va < SH3_P1SEG_BASE || l2va > SH3_P1SEG_END) {
110 _kvm_err(kd, 0, "invalid level 1 pte: out of P1");
111 goto bad;
112 }
113
114 /* read level 2 pte */
115 pteoffset = SH3_P1SEG_TO_PHYS(l2va) +
116 sizeof(pt_entry_t) * l2idx;
117 if (_kvm_pread(kd, kd->pmfd, (char *)&l2pte, sizeof(l2pte),
118 _kvm_pa2off(kd, pteoffset)) != sizeof(l2pte)) {
119 _kvm_syserr(kd, 0, "could not read level 2 pte");
120 goto bad;
121 }
122
123 /* check pte for validity */
124 if ((l2pte & PG_V) == 0) {
125 _kvm_err(kd, 0, "invalid level 2 pte: no valid bit");
126 goto bad;
127 }
128
129 *pa = (l2pte & PG_PPN) | (va & (kd->nbpg - 1));
130 return (kd->nbpg - (va & (kd->nbpg - 1)));
131 }
132
133 /*
134 * All other addresses are incorrect.
135 */
136 _kvm_err(kd, 0, "not a kernel virtual address");
137 bad:
138 *pa = (paddr_t)-1;
139 return (0);
140 }
141
142 /*
143 * Translate a physical address to a file offset in the crash dump.
144 */
145 off_t
_kvm_pa2off(kvm_t * kd,paddr_t pa)146 _kvm_pa2off(kvm_t *kd, paddr_t pa)
147 {
148 cpu_kcore_hdr_t *h = kd->cpu_data;
149 phys_ram_seg_t *seg = h->kcore_segs;
150 off_t off = kd->dump_off;
151 u_int i;
152
153 for (i = h->kcore_nsegs; i != 0; i--) {
154 if (pa >= seg->start && pa < seg->start + seg->size)
155 return (off + (pa - seg->start));
156 off += seg->size;
157 }
158
159 _kvm_err(kd, 0, "physical address out of the image (%lx)", pa);
160 return (0);
161 }
162