xref: /netbsd-src/lib/libkvm/kvm_i386.c (revision 9573504567626934c7ee01c7dce0c4bb1dfe7403)
1 /*-
2  * Copyright (c) 1989, 1992, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * This code is derived from software developed by the Computer Systems
6  * Engineering group at Lawrence Berkeley Laboratory under DARPA contract
7  * BG 91-66 and contributed to Berkeley.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. All advertising materials mentioning features or use of this software
18  *    must display the following acknowledgement:
19  *	This product includes software developed by the University of
20  *	California, Berkeley and its contributors.
21  * 4. Neither the name of the University nor the names of its contributors
22  *    may be used to endorse or promote products derived from this software
23  *    without specific prior written permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
29  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35  * SUCH DAMAGE.
36  */
37 
38 #if defined(LIBC_SCCS) && !defined(lint)
39 /* from: static char sccsid[] = "@(#)kvm_hp300.c	8.1 (Berkeley) 6/4/93"; */
40 static char *rcsid = "$Id: kvm_i386.c,v 1.7 1995/06/29 11:41:45 cgd Exp $";
41 #endif /* LIBC_SCCS and not lint */
42 
43 /*
44  * i386 machine dependent routines for kvm.  Hopefully, the forthcoming
45  * vm code will one day obsolete this module.
46  */
47 
48 #include <sys/param.h>
49 #include <sys/user.h>
50 #include <sys/proc.h>
51 #include <sys/stat.h>
52 #include <stdlib.h>
53 #include <unistd.h>
54 #include <nlist.h>
55 #include <kvm.h>
56 
57 #include <vm/vm.h>
58 #include <vm/vm_param.h>
59 
60 #include <limits.h>
61 #include <db.h>
62 
63 #include "kvm_private.h"
64 
65 #include <machine/pte.h>
66 
67 #ifndef btop
68 #define	btop(x)		(((unsigned)(x)) >> PGSHIFT)	/* XXX */
69 #define	ptob(x)		((caddr_t)((x) << PGSHIFT))	/* XXX */
70 #endif
71 
72 struct vmstate {
73 	pd_entry_t **PTDpaddr;
74 	pd_entry_t *PTD;
75 };
76 
77 #define KREAD(kd, addr, p)\
78 	(kvm_read(kd, addr, (char *)(p), sizeof(*(p))) != sizeof(*(p)))
79 
80 void
81 _kvm_freevtop(kd)
82 	kvm_t *kd;
83 {
84 	if (kd->vmst != 0) {
85 		if (kd->vmst->PTD != 0)
86 			free(kd->vmst->PTD);
87 
88 		free(kd->vmst);
89 	}
90 }
91 
92 int
93 _kvm_initvtop(kd)
94 	kvm_t *kd;
95 {
96 	struct vmstate *vm;
97 	struct nlist nlist[2];
98 	pt_entry_t *tmpPTD;
99 
100 	vm = (struct vmstate *)_kvm_malloc(kd, sizeof(*vm));
101 	if (vm == 0)
102 		return (-1);
103 	kd->vmst = vm;
104 
105 	nlist[0].n_name = "_PTDpaddr";
106 	nlist[1].n_name = 0;
107 
108 	if (kvm_nlist(kd, nlist) != 0) {
109 		_kvm_err(kd, kd->program, "bad namelist");
110 		return (-1);
111 	}
112 
113 	vm->PTDpaddr = 0;
114 	vm->PTD = 0;
115 	if (KREAD(kd, (u_long)nlist[0].n_value - KERNBASE, &vm->PTDpaddr)) {
116 		_kvm_err(kd, kd->program, "cannot read PTDpaddr");
117 		return (-1);
118 	}
119 
120 	tmpPTD = (pd_entry_t *)_kvm_malloc(kd, NBPG);
121 	if ((kvm_read(kd, (u_long)vm->PTDpaddr, tmpPTD, NBPG)) != NBPG) {
122 		free(tmpPTD);
123 		_kvm_err(kd, kd->program, "cannot read PTD");
124 		return (-1);
125 	}
126 	vm->PTD = tmpPTD;
127 	return (0);
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 (lseek(kd->pmfd, (off_t)pte_pa, 0) == -1 && errno != 0) {
168 			_kvm_syserr(kd, 0, "kvm_lseek");
169 			goto invalid;
170 		}
171 		if (read(kd->pmfd, &pte, sizeof pte) != sizeof pte) {
172 			_kvm_syserr(kd, kd->program, "kvm_read");
173 			goto invalid;
174 		}
175 	}
176 
177 	*pa = (pte & PG_FRAME) + offset;
178 	return (NBPG - offset);
179 
180 invalid:
181 	_kvm_err(kd, 0, "invalid address (%x)", va);
182 	return (0);
183 }
184