xref: /openbsd-src/lib/libkvm/kvm_i386.c (revision 799f675f6700f14e59124f9825c723e9f2ce19dc)
1 /*	$OpenBSD: kvm_i386.c,v 1.19 2006/06/09 09:46:04 mickey 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 1.19 2006/06/09 09:46:04 mickey 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 	void *PTD;
72 	paddr_t pg_frame;
73 	paddr_t pt_mask;
74 	int size;
75 	int pte_size;
76 };
77 
78 #define	pdei(vm,v)	((v) >> ((vm)->size == NBPG ? 22 : 21))
79 #define	ptei(vm,v)	(((v) & (vm)->pt_mask) >> PGSHIFT)
80 #define	PDE(vm,v)	\
81     ((vm)->size == NBPG ? ((u_int32_t *)(vm)->PTD)[pdei(vm,v)] : \
82     ((u_int64_t *)(vm)->PTD)[pdei(vm,v)])
83 #define	PG_FRAME(vm)	((vm)->pg_frame)
84 #define	pte_size(vm)	((vm)->pte_size)
85 
86 void
87 _kvm_freevtop(kvm_t *kd)
88 {
89 	if (kd->vmst != NULL) {
90 		if (kd->vmst->PTD != NULL)
91 			free(kd->vmst->PTD);
92 
93 		free(kd->vmst);
94 		kd->vmst = NULL;
95 	}
96 }
97 
98 int
99 _kvm_initvtop(kvm_t *kd)
100 {
101 	struct nlist nl[3];
102 	struct vmstate *vm;
103 	paddr_t pa;
104 	int ps;
105 
106 	vm = (struct vmstate *)_kvm_malloc(kd, sizeof(*vm));
107 	if (vm == NULL)
108 		return (-1);
109 	kd->vmst = vm;
110 
111 	vm->PTD = NULL;
112 
113 	nl[0].n_name = "_PTDpaddr";
114 	nl[1].n_name = "_PTDsize";
115 	nl[2].n_name = NULL;
116 
117 	if (kvm_nlist(kd, nl) != 0) {
118 		_kvm_err(kd, kd->program, "bad namelist");
119 		return (-1);
120 	}
121 
122 	if (_kvm_pread(kd, kd->pmfd, &ps, sizeof ps,
123 	    _kvm_pa2off(kd, nl[1].n_value - KERNBASE)) != sizeof ps)
124 		return (-1);
125 
126 	pa = 0;
127 	if (ps == NBPG) {
128 		vm->pg_frame = 0xfffff000;
129 		vm->pt_mask = 0x003ff000;
130 		vm->pte_size = 4;
131 	} else if (ps == NBPG * 4) {
132 		vm->pg_frame = 0xffffff000ULL;
133 		vm->pt_mask = 0x001ff000;
134 		vm->pte_size = 8;
135 	} else {
136 		_kvm_err(kd, 0, "PTDsize is invalid");
137 		return (-1);
138 	}
139 
140 	if (_kvm_pread(kd, kd->pmfd, &pa, vm->pte_size,
141 	    _kvm_pa2off(kd, nl[0].n_value - KERNBASE)) != vm->pte_size)
142 		return (-1);
143 
144 	vm->PTD = _kvm_malloc(kd, ps);
145 	if (vm->PTD == NULL)
146 		return (-1);
147 
148 	if (_kvm_pread(kd, kd->pmfd, vm->PTD, ps, _kvm_pa2off(kd, pa)) != ps) {
149 		free(vm->PTD);
150 		vm->PTD = NULL;
151 		return (-1);
152 	}
153 
154 	vm->size = ps;
155 	return (0);
156 }
157 
158 /*
159  * Translate a kernel virtual address to a physical address.
160  */
161 int
162 _kvm_kvatop(kvm_t *kd, u_long va, paddr_t *pa)
163 {
164 	u_long offset;
165 	struct vmstate *vm;
166 	paddr_t pte, pte_pa;
167 
168 	if (!kd->vmst) {
169 		_kvm_err(kd, 0, "vatop called before initvtop");
170 		return (0);
171 	}
172 
173 	if (ISALIVE(kd)) {
174 		_kvm_err(kd, 0, "vatop called in live kernel!");
175 		return (0);
176 	}
177 
178 	vm = kd->vmst;
179 	offset = va & PGOFSET;
180 
181 	/*
182 	 * If we are initializing (kernel page table descriptor pointer
183 	 * not yet set) * then return pa == va to avoid infinite recursion.
184 	 */
185 	if (vm->PTD == NULL) {
186 		*pa = va;
187 		return (NBPG - (int)offset);
188 	}
189 	if ((PDE(vm, va) & PG_V) == 0)
190 		goto invalid;
191 
192 	pte_pa = (PDE(vm, va) & PG_FRAME(vm)) +
193 	    (ptei(vm, va) * pte_size(vm));
194 
195 	/* XXX READ PHYSICAL XXX */
196 	pte = 0;
197 	if (_kvm_pread(kd, kd->pmfd, &pte, pte_size(vm),
198 	    _kvm_pa2off(kd, pte_pa)) != pte_size(vm))
199 		goto invalid;
200 
201 	*pa = (pte & PG_FRAME(vm)) + offset;
202 	return (NBPG - (int)offset);
203 
204 invalid:
205 	_kvm_err(kd, 0, "invalid address (%lx)", va);
206 	return (0);
207 }
208 
209 /*
210  * Translate a physical address to a file-offset in the crash-dump.
211  */
212 off_t
213 _kvm_pa2off(kvm_t *kd, paddr_t pa)
214 {
215 	return ((off_t)(kd->dump_off + pa));
216 }
217