xref: /netbsd-src/lib/libkvm/kvm_i386.c (revision 466a16a118933bd295a8a104f095714fadf9cf68)
1 /*	$NetBSD: kvm_i386.c,v 1.26 2008/10/25 23:59:06 mrg Exp $	*/
2 
3 /*-
4  * Copyright (c) 1989, 1992, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * This code is derived from software developed by the Computer Systems
8  * Engineering group at Lawrence Berkeley Laboratory under DARPA contract
9  * BG 91-66 and contributed to Berkeley.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #include <sys/cdefs.h>
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 __RCSID("$NetBSD: kvm_i386.c,v 1.26 2008/10/25 23:59:06 mrg Exp $");
42 #endif
43 #endif /* LIBC_SCCS and not lint */
44 
45 /*
46  * i386 machine dependent routines for kvm.
47  */
48 
49 #include <sys/param.h>
50 #include <sys/user.h>
51 #include <sys/stat.h>
52 #include <sys/kcore.h>
53 #include <i386/kcore.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 
61 #include <limits.h>
62 #include <db.h>
63 
64 #include "kvm_private.h"
65 
66 #include <i386/pmap.h>
67 #include <i386/pte.h>
68 #include <i386/vmparam.h>
69 
70 #ifndef btop
71 #define	btop(x)		(((unsigned)(x)) >> PGSHIFT)	/* XXX */
72 #define	ptob(x)		((caddr_t)((x) << PGSHIFT))	/* XXX */
73 #endif
74 
75 void
76 _kvm_freevtop(kd)
77 	kvm_t *kd;
78 {
79 
80 	/* Not actually used for anything right now, but safe. */
81 	if (kd->vmst != 0)
82 		free(kd->vmst);
83 }
84 
85 /*ARGSUSED*/
86 int
87 _kvm_initvtop(kd)
88 	kvm_t *kd;
89 {
90 
91 	return (0);
92 }
93 
94 /*
95  * Translate a kernel virtual address to a physical address.
96  */
97 int
98 _kvm_kvatop(kd, va, pa)
99 	kvm_t *kd;
100 	u_long va;
101 	u_long *pa;
102 {
103 	cpu_kcore_hdr_t *cpu_kh;
104 	u_long page_off;
105 	pd_entry_t pde;
106 	pt_entry_t pte;
107 	u_long pde_pa, pte_pa;
108 
109 	if (ISALIVE(kd)) {
110 		_kvm_err(kd, 0, "vatop called in live kernel!");
111 		return (0);
112 	}
113 
114 	cpu_kh = kd->cpu_data;
115 	page_off = va & PGOFSET;
116 
117 	/*
118 	 * Find and read the page directory entry.
119 	 */
120 	pde_pa = cpu_kh->pdppaddr + (pl2_pi(va) * sizeof(pd_entry_t));
121 	if (_kvm_pread(kd, kd->pmfd, (void *)&pde, sizeof(pde),
122 	    _kvm_pa2off(kd, pde_pa)) != sizeof(pde)) {
123 		_kvm_syserr(kd, 0, "could not read PDE");
124 		goto lose;
125 	}
126 
127 	/*
128 	 * Find and read the page table entry.
129 	 */
130 	if ((pde & PG_V) == 0) {
131 		_kvm_err(kd, 0, "invalid translation (invalid PDE)");
132 		goto lose;
133 	}
134 	if ((pde & PG_PS) != 0) {
135 		/*
136 		 * This is a 4MB page.
137 		 */
138 		page_off = va & ~PG_LGFRAME;
139 		*pa = (pde & PG_LGFRAME) + page_off;
140 		return (int)(NBPD_L2 - page_off);
141 	}
142 	pte_pa = (pde & PG_FRAME) + (pl1_pi(va) * sizeof(pt_entry_t));
143 	if (_kvm_pread(kd, kd->pmfd, (void *) &pte, sizeof(pte),
144 	    _kvm_pa2off(kd, pte_pa)) != sizeof(pte)) {
145 		_kvm_syserr(kd, 0, "could not read PTE");
146 		goto lose;
147 	}
148 
149 	/*
150 	 * Validate the PTE and return the physical address.
151 	 */
152 	if ((pte & PG_V) == 0) {
153 		_kvm_err(kd, 0, "invalid translation (invalid PTE)");
154 		goto lose;
155 	}
156 	*pa = (pte & PG_FRAME) + page_off;
157 	return (int)(NBPG - page_off);
158 
159  lose:
160 	*pa = (u_long)~0L;
161 	return (0);
162 }
163 
164 /*
165  * Translate a physical address to a file-offset in the crash dump.
166  */
167 off_t
168 _kvm_pa2off(kd, pa)
169 	kvm_t *kd;
170 	u_long pa;
171 {
172 	cpu_kcore_hdr_t *cpu_kh;
173 	phys_ram_seg_t *ramsegs;
174 	off_t off;
175 	int i;
176 
177 	cpu_kh = kd->cpu_data;
178 	ramsegs = (void *)((char *)(void *)cpu_kh + ALIGN(sizeof *cpu_kh));
179 
180 	off = 0;
181 	for (i = 0; i < cpu_kh->nmemsegs; i++) {
182 		if (pa >= ramsegs[i].start &&
183 		    (pa - ramsegs[i].start) < ramsegs[i].size) {
184 			off += (pa - ramsegs[i].start);
185 			break;
186 		}
187 		off += ramsegs[i].size;
188 	}
189 
190 	return (kd->dump_off + off);
191 }
192 
193 /*
194  * Machine-dependent initialization for ALL open kvm descriptors,
195  * not just those for a kernel crash dump.  Some architectures
196  * have to deal with these NOT being constants!  (i.e. m68k)
197  */
198 int
199 _kvm_mdopen(kd)
200 	kvm_t	*kd;
201 {
202 
203 	kd->usrstack = USRSTACK;
204 	kd->min_uva = VM_MIN_ADDRESS;
205 	kd->max_uva = VM_MAXUSER_ADDRESS;
206 
207 	return (0);
208 }
209