1/*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2006 Peter Wemm
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 */
27
28#include <sys/cdefs.h>
29/*
30 * i386 machine dependent routines for kvm and minidumps.
31 */
32
33#include <sys/param.h>
34#include <sys/endian.h>
35#include <stdint.h>
36#include <stdlib.h>
37#include <string.h>
38#include <unistd.h>
39#include <vm/vm.h>
40#include <kvm.h>
41
42#include "../../sys/i386/include/minidump.h"
43
44#include <limits.h>
45
46#include "kvm_private.h"
47#include "kvm_i386.h"
48
49#define	i386_round_page(x)	roundup2((kvaddr_t)(x), I386_PAGE_SIZE)
50
51struct vmstate {
52	struct minidumphdr hdr;
53};
54
55static i386_pte_pae_t
56_i386_pte_pae_get(kvm_t *kd, u_long pteindex)
57{
58	i386_pte_pae_t *pte = _kvm_pmap_get(kd, pteindex, sizeof(*pte));
59
60	return le64toh(*pte);
61}
62
63static i386_pte_t
64_i386_pte_get(kvm_t *kd, u_long pteindex)
65{
66	i386_pte_t *pte = _kvm_pmap_get(kd, pteindex, sizeof(*pte));
67
68	return le32toh(*pte);
69}
70
71static int
72_i386_minidump_probe(kvm_t *kd)
73{
74
75	return (_kvm_probe_elf_kernel(kd, ELFCLASS32, EM_386) &&
76	    _kvm_is_minidump(kd));
77}
78
79static void
80_i386_minidump_freevtop(kvm_t *kd)
81{
82	struct vmstate *vm = kd->vmst;
83
84	free(vm);
85	kd->vmst = NULL;
86}
87
88static int
89_i386_minidump_initvtop(kvm_t *kd)
90{
91	struct vmstate *vmst;
92	off_t off, dump_avail_off, sparse_off;
93
94	vmst = _kvm_malloc(kd, sizeof(*vmst));
95	if (vmst == NULL) {
96		_kvm_err(kd, kd->program, "cannot allocate vm");
97		return (-1);
98	}
99	kd->vmst = vmst;
100	if (pread(kd->pmfd, &vmst->hdr, sizeof(vmst->hdr), 0) !=
101	    sizeof(vmst->hdr)) {
102		_kvm_err(kd, kd->program, "cannot read dump header");
103		return (-1);
104	}
105	if (strncmp(MINIDUMP_MAGIC, vmst->hdr.magic, sizeof(vmst->hdr.magic)) != 0) {
106		_kvm_err(kd, kd->program, "not a minidump for this platform");
107		return (-1);
108	}
109	vmst->hdr.version = le32toh(vmst->hdr.version);
110	if (vmst->hdr.version != MINIDUMP_VERSION && vmst->hdr.version != 1) {
111		_kvm_err(kd, kd->program, "wrong minidump version. expected %d got %d",
112		    MINIDUMP_VERSION, vmst->hdr.version);
113		return (-1);
114	}
115	vmst->hdr.msgbufsize = le32toh(vmst->hdr.msgbufsize);
116	vmst->hdr.bitmapsize = le32toh(vmst->hdr.bitmapsize);
117	vmst->hdr.ptesize = le32toh(vmst->hdr.ptesize);
118	vmst->hdr.kernbase = le32toh(vmst->hdr.kernbase);
119	vmst->hdr.paemode = le32toh(vmst->hdr.paemode);
120	vmst->hdr.dumpavailsize = vmst->hdr.version == MINIDUMP_VERSION ?
121	    le32toh(vmst->hdr.dumpavailsize) : 0;
122
123	/* Skip header and msgbuf */
124	dump_avail_off = I386_PAGE_SIZE + i386_round_page(vmst->hdr.msgbufsize);
125
126	/* Skip dump_avail */
127	off = dump_avail_off + i386_round_page(vmst->hdr.dumpavailsize);
128
129	sparse_off = off + i386_round_page(vmst->hdr.bitmapsize) +
130	    i386_round_page(vmst->hdr.ptesize);
131	if (_kvm_pt_init(kd, vmst->hdr.dumpavailsize, dump_avail_off,
132	    vmst->hdr.bitmapsize, off, sparse_off, I386_PAGE_SIZE) == -1) {
133		return (-1);
134	}
135	off += i386_round_page(vmst->hdr.bitmapsize);
136
137	if (_kvm_pmap_init(kd, vmst->hdr.ptesize, off) == -1) {
138		return (-1);
139	}
140	off += i386_round_page(vmst->hdr.ptesize);
141
142	return (0);
143}
144
145static int
146_i386_minidump_vatop_pae(kvm_t *kd, kvaddr_t va, off_t *pa)
147{
148	struct vmstate *vm;
149	i386_physaddr_pae_t offset;
150	i386_pte_pae_t pte;
151	kvaddr_t pteindex;
152	i386_physaddr_pae_t a;
153	off_t ofs;
154
155	vm = kd->vmst;
156	offset = va & I386_PAGE_MASK;
157
158	if (va >= vm->hdr.kernbase) {
159		pteindex = (va - vm->hdr.kernbase) >> I386_PAGE_SHIFT;
160		if (pteindex >= vm->hdr.ptesize / sizeof(pte))
161			goto invalid;
162		pte = _i386_pte_pae_get(kd, pteindex);
163		if ((pte & I386_PG_V) == 0) {
164			_kvm_err(kd, kd->program,
165			    "_i386_minidump_vatop_pae: pte not valid");
166			goto invalid;
167		}
168		a = pte & I386_PG_FRAME_PAE;
169		ofs = _kvm_pt_find(kd, a, I386_PAGE_SIZE);
170		if (ofs == -1) {
171			_kvm_err(kd, kd->program,
172	    "_i386_minidump_vatop_pae: physical address 0x%jx not in minidump",
173			    (uintmax_t)a);
174			goto invalid;
175		}
176		*pa = ofs + offset;
177		return (I386_PAGE_SIZE - offset);
178	} else {
179		_kvm_err(kd, kd->program,
180	    "_i386_minidump_vatop_pae: virtual address 0x%jx not minidumped",
181		    (uintmax_t)va);
182		goto invalid;
183	}
184
185invalid:
186	_kvm_err(kd, 0, "invalid address (0x%jx)", (uintmax_t)va);
187	return (0);
188}
189
190static int
191_i386_minidump_vatop(kvm_t *kd, kvaddr_t va, off_t *pa)
192{
193	struct vmstate *vm;
194	i386_physaddr_t offset;
195	i386_pte_t pte;
196	kvaddr_t pteindex;
197	i386_physaddr_t a;
198	off_t ofs;
199
200	vm = kd->vmst;
201	offset = va & I386_PAGE_MASK;
202
203	if (va >= vm->hdr.kernbase) {
204		pteindex = (va - vm->hdr.kernbase) >> I386_PAGE_SHIFT;
205		if (pteindex >= vm->hdr.ptesize / sizeof(pte))
206			goto invalid;
207		pte = _i386_pte_get(kd, pteindex);
208		if ((pte & I386_PG_V) == 0) {
209			_kvm_err(kd, kd->program,
210			    "_i386_minidump_vatop: pte not valid");
211			goto invalid;
212		}
213		a = pte & I386_PG_FRAME;
214		ofs = _kvm_pt_find(kd, a, I386_PAGE_SIZE);
215		if (ofs == -1) {
216			_kvm_err(kd, kd->program,
217	    "_i386_minidump_vatop: physical address 0x%jx not in minidump",
218			    (uintmax_t)a);
219			goto invalid;
220		}
221		*pa = ofs + offset;
222		return (I386_PAGE_SIZE - offset);
223	} else {
224		_kvm_err(kd, kd->program,
225	    "_i386_minidump_vatop: virtual address 0x%jx not minidumped",
226		    (uintmax_t)va);
227		goto invalid;
228	}
229
230invalid:
231	_kvm_err(kd, 0, "invalid address (0x%jx)", (uintmax_t)va);
232	return (0);
233}
234
235static int
236_i386_minidump_kvatop(kvm_t *kd, kvaddr_t va, off_t *pa)
237{
238
239	if (ISALIVE(kd)) {
240		_kvm_err(kd, 0, "_i386_minidump_kvatop called in live kernel!");
241		return (0);
242	}
243	if (kd->vmst->hdr.paemode)
244		return (_i386_minidump_vatop_pae(kd, va, pa));
245	else
246		return (_i386_minidump_vatop(kd, va, pa));
247}
248
249static vm_prot_t
250_i386_entry_to_prot(uint64_t pte)
251{
252	vm_prot_t prot = VM_PROT_READ;
253
254	/* Source: i386/pmap.c:pmap_protect() */
255	if (pte & I386_PG_RW)
256		prot |= VM_PROT_WRITE;
257	if ((pte & I386_PG_NX) == 0)
258		prot |= VM_PROT_EXECUTE;
259
260	return prot;
261}
262
263struct i386_iter {
264	kvm_t *kd;
265	u_long nptes;
266	u_long pteindex;
267};
268
269static void
270_i386_iterator_init(struct i386_iter *it, kvm_t *kd)
271{
272	struct vmstate *vm = kd->vmst;
273
274	it->kd = kd;
275	it->pteindex = 0;
276	if (vm->hdr.paemode) {
277		it->nptes = vm->hdr.ptesize / sizeof(i386_pte_pae_t);
278	} else {
279		it->nptes = vm->hdr.ptesize / sizeof(i386_pte_t);
280	}
281	return;
282}
283
284static int
285_i386_iterator_next(struct i386_iter *it, u_long *pa, u_long *va, u_long *dva,
286    vm_prot_t *prot)
287{
288	struct vmstate *vm = it->kd->vmst;
289	i386_pte_t pte32;
290	i386_pte_pae_t pte64;
291	int found = 0;
292
293	*dva = 0;
294	*pa = 0;
295	*va = 0;
296	*dva = 0;
297	*prot = 0;
298	for (; it->pteindex < it->nptes && found == 0; it->pteindex++) {
299		if (vm->hdr.paemode) {
300			pte64 = _i386_pte_pae_get(it->kd, it->pteindex);
301			if ((pte64 & I386_PG_V) == 0)
302				continue;
303			*prot = _i386_entry_to_prot(pte64);
304			*pa = pte64 & I386_PG_FRAME_PAE;
305		} else {
306			pte32 = _i386_pte_get(it->kd, it->pteindex);
307			if ((pte32 & I386_PG_V) == 0)
308				continue;
309			*prot = _i386_entry_to_prot(pte32);
310			*pa = pte32 & I386_PG_FRAME;
311		}
312		*va = vm->hdr.kernbase + (it->pteindex << I386_PAGE_SHIFT);
313		found = 1;
314	}
315	return found;
316}
317
318static int
319_i386_minidump_walk_pages(kvm_t *kd, kvm_walk_pages_cb_t *cb, void *arg)
320{
321	struct i386_iter it;
322	u_long dva, pa, va;
323	vm_prot_t prot;
324
325	_i386_iterator_init(&it, kd);
326	while (_i386_iterator_next(&it, &pa, &va, &dva, &prot)) {
327		if (!_kvm_visit_cb(kd, cb, arg, pa, va, dva,
328		    prot, I386_PAGE_SIZE, 0)) {
329			return (0);
330		}
331	}
332	return (1);
333}
334
335static struct kvm_arch kvm_i386_minidump = {
336	.ka_probe = _i386_minidump_probe,
337	.ka_initvtop = _i386_minidump_initvtop,
338	.ka_freevtop = _i386_minidump_freevtop,
339	.ka_kvatop = _i386_minidump_kvatop,
340	.ka_native = _i386_native,
341	.ka_walk_pages = _i386_minidump_walk_pages,
342};
343
344KVM_ARCH(kvm_i386_minidump);
345