1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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__FBSDID("$FreeBSD$");
30
31/*
32 * i386 machine dependent routines for kvm and minidumps.
33 */
34
35#include <sys/param.h>
36#include <sys/endian.h>
37#include <stdint.h>
38#include <stdlib.h>
39#include <string.h>
40#include <unistd.h>
41#include <vm/vm.h>
42#include <kvm.h>
43
44#include "../../sys/i386/include/minidump.h"
45
46#include <limits.h>
47
48#include "kvm_private.h"
49#include "kvm_i386.h"
50
51#define	i386_round_page(x)	roundup2((kvaddr_t)(x), I386_PAGE_SIZE)
52
53struct vmstate {
54	struct minidumphdr hdr;
55};
56
57static i386_pte_pae_t
58_i386_pte_pae_get(kvm_t *kd, u_long pteindex)
59{
60	i386_pte_pae_t *pte = _kvm_pmap_get(kd, pteindex, sizeof(*pte));
61
62	return le64toh(*pte);
63}
64
65static i386_pte_t
66_i386_pte_get(kvm_t *kd, u_long pteindex)
67{
68	i386_pte_t *pte = _kvm_pmap_get(kd, pteindex, sizeof(*pte));
69
70	return le32toh(*pte);
71}
72
73static int
74_i386_minidump_probe(kvm_t *kd)
75{
76
77	return (_kvm_probe_elf_kernel(kd, ELFCLASS32, EM_386) &&
78	    _kvm_is_minidump(kd));
79}
80
81static void
82_i386_minidump_freevtop(kvm_t *kd)
83{
84	struct vmstate *vm = kd->vmst;
85
86	free(vm);
87	kd->vmst = NULL;
88}
89
90static int
91_i386_minidump_initvtop(kvm_t *kd)
92{
93	struct vmstate *vmst;
94	off_t off, dump_avail_off, sparse_off;
95
96	vmst = _kvm_malloc(kd, sizeof(*vmst));
97	if (vmst == NULL) {
98		_kvm_err(kd, kd->program, "cannot allocate vm");
99		return (-1);
100	}
101	kd->vmst = vmst;
102	if (pread(kd->pmfd, &vmst->hdr, sizeof(vmst->hdr), 0) !=
103	    sizeof(vmst->hdr)) {
104		_kvm_err(kd, kd->program, "cannot read dump header");
105		return (-1);
106	}
107	if (strncmp(MINIDUMP_MAGIC, vmst->hdr.magic, sizeof(vmst->hdr.magic)) != 0) {
108		_kvm_err(kd, kd->program, "not a minidump for this platform");
109		return (-1);
110	}
111	vmst->hdr.version = le32toh(vmst->hdr.version);
112	if (vmst->hdr.version != MINIDUMP_VERSION && vmst->hdr.version != 1) {
113		_kvm_err(kd, kd->program, "wrong minidump version. expected %d got %d",
114		    MINIDUMP_VERSION, vmst->hdr.version);
115		return (-1);
116	}
117	vmst->hdr.msgbufsize = le32toh(vmst->hdr.msgbufsize);
118	vmst->hdr.bitmapsize = le32toh(vmst->hdr.bitmapsize);
119	vmst->hdr.ptesize = le32toh(vmst->hdr.ptesize);
120	vmst->hdr.kernbase = le32toh(vmst->hdr.kernbase);
121	vmst->hdr.paemode = le32toh(vmst->hdr.paemode);
122	vmst->hdr.dumpavailsize = vmst->hdr.version == MINIDUMP_VERSION ?
123	    le32toh(vmst->hdr.dumpavailsize) : 0;
124
125	/* Skip header and msgbuf */
126	dump_avail_off = I386_PAGE_SIZE + i386_round_page(vmst->hdr.msgbufsize);
127
128	/* Skip dump_avail */
129	off = dump_avail_off + i386_round_page(vmst->hdr.dumpavailsize);
130
131	sparse_off = off + i386_round_page(vmst->hdr.bitmapsize) +
132	    i386_round_page(vmst->hdr.ptesize);
133	if (_kvm_pt_init(kd, vmst->hdr.dumpavailsize, dump_avail_off,
134	    vmst->hdr.bitmapsize, off, sparse_off, I386_PAGE_SIZE) == -1) {
135		return (-1);
136	}
137	off += i386_round_page(vmst->hdr.bitmapsize);
138
139	if (_kvm_pmap_init(kd, vmst->hdr.ptesize, off) == -1) {
140		return (-1);
141	}
142	off += i386_round_page(vmst->hdr.ptesize);
143
144	return (0);
145}
146
147static int
148_i386_minidump_vatop_pae(kvm_t *kd, kvaddr_t va, off_t *pa)
149{
150	struct vmstate *vm;
151	i386_physaddr_pae_t offset;
152	i386_pte_pae_t pte;
153	kvaddr_t pteindex;
154	i386_physaddr_pae_t a;
155	off_t ofs;
156
157	vm = kd->vmst;
158	offset = va & I386_PAGE_MASK;
159
160	if (va >= vm->hdr.kernbase) {
161		pteindex = (va - vm->hdr.kernbase) >> I386_PAGE_SHIFT;
162		if (pteindex >= vm->hdr.ptesize / sizeof(pte))
163			goto invalid;
164		pte = _i386_pte_pae_get(kd, pteindex);
165		if ((pte & I386_PG_V) == 0) {
166			_kvm_err(kd, kd->program,
167			    "_i386_minidump_vatop_pae: pte not valid");
168			goto invalid;
169		}
170		a = pte & I386_PG_FRAME_PAE;
171		ofs = _kvm_pt_find(kd, a, I386_PAGE_SIZE);
172		if (ofs == -1) {
173			_kvm_err(kd, kd->program,
174	    "_i386_minidump_vatop_pae: physical address 0x%jx not in minidump",
175			    (uintmax_t)a);
176			goto invalid;
177		}
178		*pa = ofs + offset;
179		return (I386_PAGE_SIZE - offset);
180	} else {
181		_kvm_err(kd, kd->program,
182	    "_i386_minidump_vatop_pae: virtual address 0x%jx not minidumped",
183		    (uintmax_t)va);
184		goto invalid;
185	}
186
187invalid:
188	_kvm_err(kd, 0, "invalid address (0x%jx)", (uintmax_t)va);
189	return (0);
190}
191
192static int
193_i386_minidump_vatop(kvm_t *kd, kvaddr_t va, off_t *pa)
194{
195	struct vmstate *vm;
196	i386_physaddr_t offset;
197	i386_pte_t pte;
198	kvaddr_t pteindex;
199	i386_physaddr_t a;
200	off_t ofs;
201
202	vm = kd->vmst;
203	offset = va & I386_PAGE_MASK;
204
205	if (va >= vm->hdr.kernbase) {
206		pteindex = (va - vm->hdr.kernbase) >> I386_PAGE_SHIFT;
207		if (pteindex >= vm->hdr.ptesize / sizeof(pte))
208			goto invalid;
209		pte = _i386_pte_get(kd, pteindex);
210		if ((pte & I386_PG_V) == 0) {
211			_kvm_err(kd, kd->program,
212			    "_i386_minidump_vatop: pte not valid");
213			goto invalid;
214		}
215		a = pte & I386_PG_FRAME;
216		ofs = _kvm_pt_find(kd, a, I386_PAGE_SIZE);
217		if (ofs == -1) {
218			_kvm_err(kd, kd->program,
219	    "_i386_minidump_vatop: physical address 0x%jx not in minidump",
220			    (uintmax_t)a);
221			goto invalid;
222		}
223		*pa = ofs + offset;
224		return (I386_PAGE_SIZE - offset);
225	} else {
226		_kvm_err(kd, kd->program,
227	    "_i386_minidump_vatop: virtual address 0x%jx not minidumped",
228		    (uintmax_t)va);
229		goto invalid;
230	}
231
232invalid:
233	_kvm_err(kd, 0, "invalid address (0x%jx)", (uintmax_t)va);
234	return (0);
235}
236
237static int
238_i386_minidump_kvatop(kvm_t *kd, kvaddr_t va, off_t *pa)
239{
240
241	if (ISALIVE(kd)) {
242		_kvm_err(kd, 0, "_i386_minidump_kvatop called in live kernel!");
243		return (0);
244	}
245	if (kd->vmst->hdr.paemode)
246		return (_i386_minidump_vatop_pae(kd, va, pa));
247	else
248		return (_i386_minidump_vatop(kd, va, pa));
249}
250
251static vm_prot_t
252_i386_entry_to_prot(uint64_t pte)
253{
254	vm_prot_t prot = VM_PROT_READ;
255
256	/* Source: i386/pmap.c:pmap_protect() */
257	if (pte & I386_PG_RW)
258		prot |= VM_PROT_WRITE;
259	if ((pte & I386_PG_NX) == 0)
260		prot |= VM_PROT_EXECUTE;
261
262	return prot;
263}
264
265struct i386_iter {
266	kvm_t *kd;
267	u_long nptes;
268	u_long pteindex;
269};
270
271static void
272_i386_iterator_init(struct i386_iter *it, kvm_t *kd)
273{
274	struct vmstate *vm = kd->vmst;
275
276	it->kd = kd;
277	it->pteindex = 0;
278	if (vm->hdr.paemode) {
279		it->nptes = vm->hdr.ptesize / sizeof(i386_pte_pae_t);
280	} else {
281		it->nptes = vm->hdr.ptesize / sizeof(i386_pte_t);
282	}
283	return;
284}
285
286static int
287_i386_iterator_next(struct i386_iter *it, u_long *pa, u_long *va, u_long *dva,
288    vm_prot_t *prot)
289{
290	struct vmstate *vm = it->kd->vmst;
291	i386_pte_t pte32;
292	i386_pte_pae_t pte64;
293	int found = 0;
294
295	*dva = 0;
296	*pa = 0;
297	*va = 0;
298	*dva = 0;
299	*prot = 0;
300	for (; it->pteindex < it->nptes && found == 0; it->pteindex++) {
301		if (vm->hdr.paemode) {
302			pte64 = _i386_pte_pae_get(it->kd, it->pteindex);
303			if ((pte64 & I386_PG_V) == 0)
304				continue;
305			*prot = _i386_entry_to_prot(pte64);
306			*pa = pte64 & I386_PG_FRAME_PAE;
307		} else {
308			pte32 = _i386_pte_get(it->kd, it->pteindex);
309			if ((pte32 & I386_PG_V) == 0)
310				continue;
311			*prot = _i386_entry_to_prot(pte32);
312			*pa = pte32 & I386_PG_FRAME;
313		}
314		*va = vm->hdr.kernbase + (it->pteindex << I386_PAGE_SHIFT);
315		found = 1;
316	}
317	return found;
318}
319
320static int
321_i386_minidump_walk_pages(kvm_t *kd, kvm_walk_pages_cb_t *cb, void *arg)
322{
323	struct i386_iter it;
324	u_long dva, pa, va;
325	vm_prot_t prot;
326
327	_i386_iterator_init(&it, kd);
328	while (_i386_iterator_next(&it, &pa, &va, &dva, &prot)) {
329		if (!_kvm_visit_cb(kd, cb, arg, pa, va, dva,
330		    prot, I386_PAGE_SIZE, 0)) {
331			return (0);
332		}
333	}
334	return (1);
335}
336
337static struct kvm_arch kvm_i386_minidump = {
338	.ka_probe = _i386_minidump_probe,
339	.ka_initvtop = _i386_minidump_initvtop,
340	.ka_freevtop = _i386_minidump_freevtop,
341	.ka_kvatop = _i386_minidump_kvatop,
342	.ka_native = _i386_native,
343	.ka_walk_pages = _i386_minidump_walk_pages,
344};
345
346KVM_ARCH(kvm_i386_minidump);
347