xref: /openbsd-src/lib/libkvm/kvm_amd64.c (revision daf88648c0e349d5c02e1504293082072c981640)
1 /*	$OpenBSD: kvm_amd64.c,v 1.5 2007/01/08 18:54:12 deraadt Exp $	*/
2 /*	$NetBSD: kvm_x86_64.c,v 1.3 2002/06/05 22:01:55 fvdl Exp $	*/
3 
4 /*-
5  * Copyright (c) 1989, 1992, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * This code is derived from software developed by the Computer Systems
9  * Engineering group at Lawrence Berkeley Laboratory under DARPA contract
10  * BG 91-66 and contributed to Berkeley.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  * 3. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  */
36 
37 #include <sys/cdefs.h>
38 
39 /*
40  * x86-64 machine dependent routines for kvm.
41  */
42 
43 #include <sys/param.h>
44 #include <sys/user.h>
45 #include <sys/proc.h>
46 #include <sys/stat.h>
47 #include <sys/kcore.h>
48 #include <machine/kcore.h>
49 #include <stdlib.h>
50 #include <unistd.h>
51 #include <nlist.h>
52 #include <kvm.h>
53 
54 #include <uvm/uvm_extern.h>
55 
56 #include <limits.h>
57 #include <db.h>
58 
59 #include "kvm_private.h"
60 
61 #include <machine/pmap.h>
62 #include <machine/pte.h>
63 #include <machine/vmparam.h>
64 
65 void
66 _kvm_freevtop(kvm_t *kd)
67 {
68 
69 	/* Not actually used for anything right now, but safe. */
70 	if (kd->vmst != NULL) {
71 		free(kd->vmst);
72 		kd->vmst = NULL;
73 	}
74 }
75 
76 /*ARGSUSED*/
77 int
78 _kvm_initvtop(kvm_t *kd)
79 {
80 
81 	return (0);
82 }
83 
84 /*
85  * Translate a kernel virtual address to a physical address.
86  */
87 int
88 _kvm_kvatop(kvm_t *kd, u_long va, paddr_t *pa)
89 {
90 	cpu_kcore_hdr_t *cpu_kh;
91 	paddr_t pde_pa, pte_pa;
92 	u_long page_off;
93 	pd_entry_t pde;
94 	pt_entry_t pte;
95 
96 	if (ISALIVE(kd)) {
97 		_kvm_err(kd, 0, "vatop called in live kernel!");
98 		return (0);
99 	}
100 
101 	cpu_kh = kd->cpu_data;
102 	page_off = va & PGOFSET;
103 
104 	/*
105 	 * Find and read all entries to get to the pa.
106 	 */
107 
108 	/*
109 	 * Level 4.
110 	 */
111 	pde_pa = cpu_kh->ptdpaddr + (pl4_pi(va) * sizeof(pd_entry_t));
112 	if (pread(kd->pmfd, (void *)&pde, sizeof(pde),
113 	    _kvm_pa2off(kd, pde_pa)) != sizeof(pde)) {
114 		_kvm_syserr(kd, 0, "could not read PT level 4 entry");
115 		goto lose;
116 	}
117 	if ((pde & PG_V) == 0) {
118 		_kvm_err(kd, 0, "invalid translation (invalid level 4 PDE)");
119 		goto lose;
120 	}
121 
122 	/*
123 	 * Level 3.
124 	 */
125 	pde_pa = (pde & PG_FRAME) + (pl3_pi(va) * sizeof(pd_entry_t));
126 	if (pread(kd->pmfd, (void *)&pde, sizeof(pde),
127 	    _kvm_pa2off(kd, pde_pa)) != sizeof(pde)) {
128 		_kvm_syserr(kd, 0, "could not read PT level 3 entry");
129 		goto lose;
130 	}
131 	if ((pde & PG_V) == 0) {
132 		_kvm_err(kd, 0, "invalid translation (invalid level 3 PDE)");
133 		goto lose;
134 	}
135 
136 	/*
137 	 * Level 2.
138 	 */
139 	pde_pa = (pde & PG_FRAME) + (pl2_pi(va) * sizeof(pd_entry_t));
140 	if (pread(kd->pmfd, (void *)&pde, sizeof(pde),
141 	    _kvm_pa2off(kd, pde_pa)) != sizeof(pde)) {
142 		_kvm_syserr(kd, 0, "could not read PT level 2 entry");
143 		goto lose;
144 	}
145 	if ((pde & PG_V) == 0) {
146 		_kvm_err(kd, 0, "invalid translation (invalid level 2 PDE)");
147 		goto lose;
148 	}
149 
150 
151 	/*
152 	 * Level 1.
153 	 */
154 	pte_pa = (pde & PG_FRAME) + (pl1_pi(va) * sizeof(pt_entry_t));
155 	if (pread(kd->pmfd, (void *) &pte, sizeof(pte),
156 	    _kvm_pa2off(kd, pte_pa)) != sizeof(pte)) {
157 		_kvm_syserr(kd, 0, "could not read PTE");
158 		goto lose;
159 	}
160 	/*
161 	 * Validate the PTE and return the physical address.
162 	 */
163 	if ((pte & PG_V) == 0) {
164 		_kvm_err(kd, 0, "invalid translation (invalid PTE)");
165 		goto lose;
166 	}
167 	*pa = (pte & PG_FRAME) + page_off;
168 	return (int)(NBPG - page_off);
169 
170  lose:
171 	*pa = (u_long)~0L;
172 	return (0);
173 }
174 
175 /*
176  * Translate a physical address to a file-offset in the crash dump.
177  */
178 off_t
179 _kvm_pa2off(kvm_t *kd, paddr_t pa)
180 {
181 	cpu_kcore_hdr_t *cpu_kh;
182 	phys_ram_seg_t *ramsegs;
183 	off_t off;
184 	int i;
185 
186 	cpu_kh = kd->cpu_data;
187 	ramsegs = (void *)((char *)(void *)cpu_kh + ALIGN(sizeof *cpu_kh));
188 
189 	off = 0;
190 	for (i = 0; i < cpu_kh->nmemsegs; i++) {
191 		if (pa >= ramsegs[i].start &&
192 		    (pa - ramsegs[i].start) < ramsegs[i].size) {
193 			off += (pa - ramsegs[i].start);
194 			break;
195 		}
196 		off += ramsegs[i].size;
197 	}
198 
199 	return (kd->dump_off + off);
200 }
201