xref: /openbsd-src/lib/libkvm/kvm_amd64.c (revision 48950c12d106c85f315112191a0228d7b83b9510)
1 /*	$OpenBSD: kvm_amd64.c,v 1.9 2012/12/05 23:20:02 deraadt Exp $	*/
2 /*	$NetBSD: kvm_x86_64.c,v 1.3 2002/06/05 22:01:55 fvdl 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 /*
38  * x86-64 machine dependent routines for kvm.
39  */
40 
41 #include <sys/param.h>
42 #include <sys/user.h>
43 #include <sys/proc.h>
44 #include <sys/stat.h>
45 #include <sys/kcore.h>
46 #include <machine/kcore.h>
47 #include <stdlib.h>
48 #include <unistd.h>
49 #include <nlist.h>
50 #include <kvm.h>
51 
52 #include <uvm/uvm_extern.h>
53 
54 #include <limits.h>
55 #include <db.h>
56 
57 #include "kvm_private.h"
58 
59 #include <machine/pmap.h>
60 #include <machine/pte.h>
61 #include <machine/vmparam.h>
62 
63 void
64 _kvm_freevtop(kvm_t *kd)
65 {
66 
67 	/* Not actually used for anything right now, but safe. */
68 	if (kd->vmst != NULL) {
69 		free(kd->vmst);
70 		kd->vmst = NULL;
71 	}
72 }
73 
74 /*ARGSUSED*/
75 int
76 _kvm_initvtop(kvm_t *kd)
77 {
78 
79 	return (0);
80 }
81 
82 /*
83  * Translate a kernel virtual address to a physical address.
84  */
85 int
86 _kvm_kvatop(kvm_t *kd, u_long va, paddr_t *pa)
87 {
88 	cpu_kcore_hdr_t *cpu_kh;
89 	paddr_t pde_pa, pte_pa;
90 	u_long page_off;
91 	pd_entry_t pde;
92 	pt_entry_t pte;
93 
94 	if (ISALIVE(kd)) {
95 		_kvm_err(kd, 0, "vatop called in live kernel!");
96 		return (0);
97 	}
98 
99 	page_off = va & PAGE_MASK;
100 
101 	if (va >= PMAP_DIRECT_BASE && va <= PMAP_DIRECT_END) {
102 		*pa = va - PMAP_DIRECT_BASE;
103 		return (int)(PAGE_SIZE - page_off);
104 	}
105 
106 	cpu_kh = kd->cpu_data;
107 
108 	/*
109 	 * Find and read all entries to get to the pa.
110 	 */
111 
112 	/*
113 	 * Level 4.
114 	 */
115 	pde_pa = cpu_kh->ptdpaddr + (pl4_pi(va) * sizeof(pd_entry_t));
116 	if (pread(kd->pmfd, (void *)&pde, sizeof(pde),
117 	    _kvm_pa2off(kd, pde_pa)) != sizeof(pde)) {
118 		_kvm_syserr(kd, 0, "could not read PT level 4 entry");
119 		goto lose;
120 	}
121 	if ((pde & PG_V) == 0) {
122 		_kvm_err(kd, 0, "invalid translation (invalid level 4 PDE)");
123 		goto lose;
124 	}
125 
126 	/*
127 	 * Level 3.
128 	 */
129 	pde_pa = (pde & PG_FRAME) + (pl3_pi(va) * sizeof(pd_entry_t));
130 	if (pread(kd->pmfd, (void *)&pde, sizeof(pde),
131 	    _kvm_pa2off(kd, pde_pa)) != sizeof(pde)) {
132 		_kvm_syserr(kd, 0, "could not read PT level 3 entry");
133 		goto lose;
134 	}
135 	if ((pde & PG_V) == 0) {
136 		_kvm_err(kd, 0, "invalid translation (invalid level 3 PDE)");
137 		goto lose;
138 	}
139 
140 	/*
141 	 * Level 2.
142 	 */
143 	pde_pa = (pde & PG_FRAME) + (pl2_pi(va) * sizeof(pd_entry_t));
144 	if (pread(kd->pmfd, (void *)&pde, sizeof(pde),
145 	    _kvm_pa2off(kd, pde_pa)) != sizeof(pde)) {
146 		_kvm_syserr(kd, 0, "could not read PT level 2 entry");
147 		goto lose;
148 	}
149 	if ((pde & PG_V) == 0) {
150 		_kvm_err(kd, 0, "invalid translation (invalid level 2 PDE)");
151 		goto lose;
152 	}
153 
154 	/*
155 	 * Might be a large page.
156 	 */
157 	if ((pde & PG_PS) != 0) {
158 		page_off = va & (NBPD_L2 - 1);
159 		*pa = (pde & PG_LGFRAME) | page_off;
160 		return (int)(NBPD_L2 - page_off);
161 	}
162 
163 	/*
164 	 * Level 1.
165 	 */
166 	pte_pa = (pde & PG_FRAME) + (pl1_pi(va) * sizeof(pt_entry_t));
167 	if (pread(kd->pmfd, (void *) &pte, sizeof(pte),
168 	    _kvm_pa2off(kd, pte_pa)) != sizeof(pte)) {
169 		_kvm_syserr(kd, 0, "could not read PTE");
170 		goto lose;
171 	}
172 	/*
173 	 * Validate the PTE and return the physical address.
174 	 */
175 	if ((pte & PG_V) == 0) {
176 		_kvm_err(kd, 0, "invalid translation (invalid PTE)");
177 		goto lose;
178 	}
179 	*pa = (pte & PG_FRAME) + page_off;
180 	return (int)(PAGE_SIZE - page_off);
181 
182  lose:
183 	*pa = (u_long)~0L;
184 	return (0);
185 }
186 
187 /*
188  * Translate a physical address to a file-offset in the crash dump.
189  */
190 off_t
191 _kvm_pa2off(kvm_t *kd, paddr_t pa)
192 {
193 	cpu_kcore_hdr_t *cpu_kh;
194 	phys_ram_seg_t *ramsegs;
195 	off_t off;
196 	int i;
197 
198 	cpu_kh = kd->cpu_data;
199 	ramsegs = (void *)((char *)(void *)cpu_kh + ALIGN(sizeof *cpu_kh));
200 
201 	off = 0;
202 	for (i = 0; i < cpu_kh->nmemsegs; i++) {
203 		if (pa >= ramsegs[i].start &&
204 		    (pa - ramsegs[i].start) < ramsegs[i].size) {
205 			off += (pa - ramsegs[i].start);
206 			break;
207 		}
208 		off += ramsegs[i].size;
209 	}
210 
211 	if (i == cpu_kh->nmemsegs)
212 		_kvm_err(kd, 0, "pa %lx not in dump", pa);
213 
214 	return (kd->dump_off + off);
215 }
216