xref: /openbsd-src/lib/libkvm/kvm_i386.c (revision b2ea75c1b17e1a9a339660e7ed45cd24946b230e)
1 /*	$OpenBSD: kvm_i386.c,v 1.7 2001/05/18 09:08:37 art 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. All advertising materials mentioning features or use of this software
21  *    must display the following acknowledgement:
22  *	This product includes software developed by the University of
23  *	California, Berkeley and its contributors.
24  * 4. Neither the name of the University nor the names of its contributors
25  *    may be used to endorse or promote products derived from this software
26  *    without specific prior written permission.
27  *
28  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
29  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
30  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
31  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
32  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
33  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
34  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
35  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
36  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
37  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
38  * SUCH DAMAGE.
39  */
40 
41 #if defined(LIBC_SCCS) && !defined(lint)
42 #if 0
43 static char sccsid[] = "@(#)kvm_hp300.c	8.1 (Berkeley) 6/4/93";
44 #else
45 static char *rcsid = "$OpenBSD: kvm_i386.c,v 1.7 2001/05/18 09:08:37 art Exp $";
46 #endif
47 #endif /* LIBC_SCCS and not lint */
48 
49 /*
50  * i386 machine dependent routines for kvm.  Hopefully, the forthcoming
51  * vm code will one day obsolete this module.
52  */
53 
54 #include <sys/param.h>
55 #include <sys/user.h>
56 #include <sys/proc.h>
57 #include <sys/stat.h>
58 #include <stdlib.h>
59 #include <unistd.h>
60 #include <nlist.h>
61 #include <kvm.h>
62 
63 #include <vm/vm.h>
64 #include <vm/vm_param.h>
65 
66 #include <limits.h>
67 #include <db.h>
68 
69 #include "kvm_private.h"
70 
71 #include <machine/pte.h>
72 
73 struct vmstate {
74 	pd_entry_t *PTD;
75 };
76 
77 void
78 _kvm_freevtop(kd)
79 	kvm_t *kd;
80 {
81 	if (kd->vmst != 0) {
82 		if (kd->vmst->PTD != 0)
83 			free(kd->vmst->PTD);
84 
85 		free(kd->vmst);
86 	}
87 }
88 
89 int
90 _kvm_initvtop(kd)
91 	kvm_t *kd;
92 {
93 	struct vmstate *vm;
94 	struct nlist nlist[2];
95 	u_long pa;
96 
97 	vm = (struct vmstate *)_kvm_malloc(kd, sizeof(*vm));
98 	if (vm == 0)
99 		return (-1);
100 	kd->vmst = vm;
101 
102 	nlist[0].n_name = "_PTDpaddr";
103 	nlist[1].n_name = 0;
104 
105 	if (kvm_nlist(kd, nlist) != 0) {
106 		_kvm_err(kd, kd->program, "bad namelist");
107 		return (-1);
108 	}
109 
110 	vm->PTD = 0;
111 
112 	if (_kvm_pread(kd, kd->pmfd, &pa, sizeof pa, (off_t)_kvm_pa2off(kd, nlist[0].n_value - KERNBASE)) != sizeof pa) {
113 		goto invalid;
114 	}
115 
116 	vm->PTD = (pd_entry_t *)_kvm_malloc(kd, NBPG);
117 
118 	if (_kvm_pread(kd, kd->pmfd, vm->PTD, NBPG, (off_t)_kvm_pa2off(kd, pa)) != NBPG) {
119 		goto invalid;
120 	}
121 
122 	return (0);
123 
124 invalid:
125 	if (vm->PTD != 0)
126 		free(vm->PTD);
127 	return (-1);
128 }
129 
130 /*
131  * Translate a kernel virtual address to a physical address.
132  */
133 int
134 _kvm_kvatop(kd, va, pa)
135 	kvm_t *kd;
136 	u_long va;
137 	u_long *pa;
138 {
139 	struct vmstate *vm;
140 	u_long offset;
141 	u_long pte_pa;
142 	pt_entry_t pte;
143 
144 	if (ISALIVE(kd)) {
145 		_kvm_err(kd, 0, "vatop called in live kernel!");
146 		return(0);
147 	}
148 
149 	vm = kd->vmst;
150 	offset = va & PGOFSET;
151 
152         /*
153          * If we are initializing (kernel page table descriptor pointer
154 	 * not yet set) * then return pa == va to avoid infinite recursion.
155          */
156         if (vm->PTD == 0) {
157                 *pa = va;
158                 return (NBPG - offset);
159         }
160 	if ((vm->PTD[pdei(va)] & PG_V) == 0)
161 		goto invalid;
162 
163 	pte_pa = (vm->PTD[pdei(va)] & PG_FRAME) +
164 	    (ptei(va) * sizeof(pt_entry_t));
165 	/* XXX READ PHYSICAL XXX */
166 	{
167 		if (_kvm_pread(kd, kd->pmfd, &pte, sizeof pte, (off_t)_kvm_pa2off(kd, pte_pa)) != sizeof pte) {
168 			goto invalid;
169 		}
170 	}
171 
172 	*pa = (pte & PG_FRAME) + offset;
173 	return (NBPG - offset);
174 
175 invalid:
176 	_kvm_err(kd, 0, "invalid address (%lx)", va);
177 	return (0);
178 }
179 
180 /*
181  * Translate a physical address to a file-offset in the crash-dump.
182  */
183 off_t
184 _kvm_pa2off(kd, pa)
185 	kvm_t *kd;
186 	u_long pa;
187 {
188 	return((off_t)(kd->dump_off + pa));
189 }
190