xref: /openbsd-src/lib/libkvm/kvm_i386.c (revision b725ae7711052a2233e31a66fefb8a752c388d7a)
1 /*	$OpenBSD: kvm_i386.c,v 1.11 2003/06/02 20:18:40 millert Exp $ */
2 /*	$NetBSD: kvm_i386.c,v 1.9 1996/03/18 22:33:38 thorpej 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 #if defined(LIBC_SCCS) && !defined(lint)
38 #if 0
39 static char sccsid[] = "@(#)kvm_hp300.c	8.1 (Berkeley) 6/4/93";
40 #else
41 static char *rcsid = "$OpenBSD: kvm_i386.c,v 1.11 2003/06/02 20:18:40 millert Exp $";
42 #endif
43 #endif /* LIBC_SCCS and not lint */
44 
45 /*
46  * i386 machine dependent routines for kvm.  Hopefully, the forthcoming
47  * vm code will one day obsolete this module.
48  */
49 
50 #include <sys/param.h>
51 #include <sys/user.h>
52 #include <sys/proc.h>
53 #include <sys/stat.h>
54 #include <stdlib.h>
55 #include <unistd.h>
56 #include <nlist.h>
57 #include <kvm.h>
58 
59 #include <uvm/uvm_extern.h>
60 #include <machine/vmparam.h>
61 #include <machine/pmap.h>
62 
63 #include <limits.h>
64 #include <db.h>
65 
66 #include "kvm_private.h"
67 
68 #include <machine/pte.h>
69 
70 struct vmstate {
71 	pd_entry_t *PTD;
72 };
73 
74 void
75 _kvm_freevtop(kd)
76 	kvm_t *kd;
77 {
78 	if (kd->vmst != 0) {
79 		if (kd->vmst->PTD != 0)
80 			free(kd->vmst->PTD);
81 
82 		free(kd->vmst);
83 	}
84 }
85 
86 int
87 _kvm_initvtop(kd)
88 	kvm_t *kd;
89 {
90 	struct vmstate *vm;
91 	struct nlist nlist[2];
92 	u_long pa;
93 
94 	vm = (struct vmstate *)_kvm_malloc(kd, sizeof(*vm));
95 	if (vm == 0)
96 		return (-1);
97 	kd->vmst = vm;
98 
99 	nlist[0].n_name = "_PTDpaddr";
100 	nlist[1].n_name = 0;
101 
102 	if (kvm_nlist(kd, nlist) != 0) {
103 		_kvm_err(kd, kd->program, "bad namelist");
104 		return (-1);
105 	}
106 
107 	vm->PTD = 0;
108 
109 	if (_kvm_pread(kd, kd->pmfd, &pa, sizeof pa, (off_t)_kvm_pa2off(kd, nlist[0].n_value - KERNBASE)) != sizeof pa) {
110 		goto invalid;
111 	}
112 
113 	vm->PTD = (pd_entry_t *)_kvm_malloc(kd, NBPG);
114 
115 	if (_kvm_pread(kd, kd->pmfd, vm->PTD, NBPG, (off_t)_kvm_pa2off(kd, pa)) != NBPG) {
116 		goto invalid;
117 	}
118 
119 	return (0);
120 
121 invalid:
122 	if (vm->PTD != 0)
123 		free(vm->PTD);
124 	return (-1);
125 }
126 
127 /*
128  * Translate a kernel virtual address to a physical address.
129  */
130 int
131 _kvm_kvatop(kd, va, pa)
132 	kvm_t *kd;
133 	u_long va;
134 	u_long *pa;
135 {
136 	struct vmstate *vm;
137 	u_long offset;
138 	u_long pte_pa;
139 	pt_entry_t pte;
140 
141 	if (ISALIVE(kd)) {
142 		_kvm_err(kd, 0, "vatop called in live kernel!");
143 		return(0);
144 	}
145 
146 	vm = kd->vmst;
147 	offset = va & PGOFSET;
148 
149         /*
150          * If we are initializing (kernel page table descriptor pointer
151 	 * not yet set) * then return pa == va to avoid infinite recursion.
152          */
153         if (vm->PTD == 0) {
154                 *pa = va;
155                 return (NBPG - offset);
156         }
157 	if ((vm->PTD[pdei(va)] & PG_V) == 0)
158 		goto invalid;
159 
160 	pte_pa = (vm->PTD[pdei(va)] & PG_FRAME) +
161 	    (ptei(va) * sizeof(pt_entry_t));
162 	/* XXX READ PHYSICAL XXX */
163 	{
164 		if (_kvm_pread(kd, kd->pmfd, &pte, sizeof pte, (off_t)_kvm_pa2off(kd, pte_pa)) != sizeof pte) {
165 			goto invalid;
166 		}
167 	}
168 
169 	*pa = (pte & PG_FRAME) + offset;
170 	return (NBPG - offset);
171 
172 invalid:
173 	_kvm_err(kd, 0, "invalid address (%lx)", va);
174 	return (0);
175 }
176 
177 /*
178  * Translate a physical address to a file-offset in the crash-dump.
179  */
180 off_t
181 _kvm_pa2off(kd, pa)
182 	kvm_t *kd;
183 	u_long pa;
184 {
185 	return((off_t)(kd->dump_off + pa));
186 }
187