1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
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
37/*
38 * i386 machine dependent routines for kvm.  Hopefully, the forthcoming
39 * vm code will one day obsolete this module.
40 */
41
42#include <sys/param.h>
43#include <sys/endian.h>
44#include <stdint.h>
45#include <stdlib.h>
46#include <string.h>
47#include <unistd.h>
48#include <vm/vm.h>
49#include <kvm.h>
50
51#ifdef __i386__
52#include <machine/vmparam.h>		/* For KERNBASE. */
53#endif
54
55#include <limits.h>
56
57#include "kvm_private.h"
58#include "kvm_i386.h"
59
60struct vmstate {
61	void		*PTD;
62	int		pae;
63	size_t		phnum;
64	GElf_Phdr	*phdr;
65};
66
67/*
68 * Translate a physical memory address to a file-offset in the crash-dump.
69 */
70static size_t
71_kvm_pa2off(kvm_t *kd, uint64_t pa, off_t *ofs)
72{
73	struct vmstate *vm = kd->vmst;
74	GElf_Phdr *p;
75	size_t n;
76
77	if (kd->rawdump) {
78		*ofs = pa;
79		return (I386_PAGE_SIZE - (pa & I386_PAGE_MASK));
80	}
81
82	p = vm->phdr;
83	n = vm->phnum;
84	while (n && (pa < p->p_paddr || pa >= p->p_paddr + p->p_memsz))
85		p++, n--;
86	if (n == 0)
87		return (0);
88	*ofs = (pa - p->p_paddr) + p->p_offset;
89	return (I386_PAGE_SIZE - (pa & I386_PAGE_MASK));
90}
91
92static void
93_i386_freevtop(kvm_t *kd)
94{
95	struct vmstate *vm = kd->vmst;
96
97	if (vm->PTD)
98		free(vm->PTD);
99	free(vm->phdr);
100	free(vm);
101	kd->vmst = NULL;
102}
103
104static int
105_i386_probe(kvm_t *kd)
106{
107
108	return (_kvm_probe_elf_kernel(kd, ELFCLASS32, EM_386) &&
109	    !_kvm_is_minidump(kd));
110}
111
112static int
113_i386_initvtop(kvm_t *kd)
114{
115	struct kvm_nlist nl[2];
116	i386_physaddr_t pa;
117	kvaddr_t kernbase;
118	char		*PTD;
119	int		i;
120
121	kd->vmst = (struct vmstate *)_kvm_malloc(kd, sizeof(struct vmstate));
122	if (kd->vmst == NULL) {
123		_kvm_err(kd, kd->program, "cannot allocate vm");
124		return (-1);
125	}
126	kd->vmst->PTD = 0;
127
128	if (kd->rawdump == 0) {
129		if (_kvm_read_core_phdrs(kd, &kd->vmst->phnum,
130		    &kd->vmst->phdr) == -1)
131			return (-1);
132	}
133
134	nl[0].n_name = "kernbase";
135	nl[1].n_name = 0;
136
137	if (kvm_nlist2(kd, nl) != 0) {
138#ifdef __i386__
139		kernbase = KERNBASE;	/* for old kernels */
140#else
141		_kvm_err(kd, kd->program, "cannot resolve kernbase");
142		return (-1);
143#endif
144	} else
145		kernbase = nl[0].n_value;
146
147	nl[0].n_name = "IdlePDPT";
148	nl[1].n_name = 0;
149
150	if (kvm_nlist2(kd, nl) == 0) {
151		i386_physaddr_pae_t pa64;
152
153		if (kvm_read2(kd, (nl[0].n_value - kernbase), &pa,
154		    sizeof(pa)) != sizeof(pa)) {
155			_kvm_err(kd, kd->program, "cannot read IdlePDPT");
156			return (-1);
157		}
158		pa = le32toh(pa);
159		PTD = _kvm_malloc(kd, 4 * I386_PAGE_SIZE);
160		if (PTD == NULL) {
161			_kvm_err(kd, kd->program, "cannot allocate PTD");
162			return (-1);
163		}
164		for (i = 0; i < 4; i++) {
165			if (kvm_read2(kd, pa + (i * sizeof(pa64)), &pa64,
166			    sizeof(pa64)) != sizeof(pa64)) {
167				_kvm_err(kd, kd->program, "Cannot read PDPT");
168				free(PTD);
169				return (-1);
170			}
171			pa64 = le64toh(pa64);
172			if (kvm_read2(kd, pa64 & I386_PG_FRAME_PAE,
173			    PTD + (i * I386_PAGE_SIZE), I386_PAGE_SIZE) !=
174			    I386_PAGE_SIZE) {
175				_kvm_err(kd, kd->program, "cannot read PDPT");
176				free(PTD);
177				return (-1);
178			}
179		}
180		kd->vmst->PTD = PTD;
181		kd->vmst->pae = 1;
182	} else {
183		nl[0].n_name = "IdlePTD";
184		nl[1].n_name = 0;
185
186		if (kvm_nlist2(kd, nl) != 0) {
187			_kvm_err(kd, kd->program, "bad namelist");
188			return (-1);
189		}
190		if (kvm_read2(kd, (nl[0].n_value - kernbase), &pa,
191		    sizeof(pa)) != sizeof(pa)) {
192			_kvm_err(kd, kd->program, "cannot read IdlePTD");
193			return (-1);
194		}
195		pa = le32toh(pa);
196		PTD = _kvm_malloc(kd, I386_PAGE_SIZE);
197		if (PTD == NULL) {
198			_kvm_err(kd, kd->program, "cannot allocate PTD");
199			return (-1);
200		}
201		if (kvm_read2(kd, pa, PTD, I386_PAGE_SIZE) != I386_PAGE_SIZE) {
202			_kvm_err(kd, kd->program, "cannot read PTD");
203			return (-1);
204		}
205		kd->vmst->PTD = PTD;
206		kd->vmst->pae = 0;
207	}
208	return (0);
209}
210
211static int
212_i386_vatop(kvm_t *kd, kvaddr_t va, off_t *pa)
213{
214	struct vmstate *vm;
215	i386_physaddr_t offset;
216	i386_physaddr_t pte_pa;
217	i386_pde_t pde;
218	i386_pte_t pte;
219	kvaddr_t pdeindex;
220	kvaddr_t pteindex;
221	size_t s;
222	i386_physaddr_t a;
223	off_t ofs;
224	i386_pde_t *PTD;
225
226	vm = kd->vmst;
227	PTD = (i386_pde_t *)vm->PTD;
228	offset = va & I386_PAGE_MASK;
229
230	/*
231	 * If we are initializing (kernel page table descriptor pointer
232	 * not yet set) then return pa == va to avoid infinite recursion.
233	 */
234	if (PTD == NULL) {
235		s = _kvm_pa2off(kd, va, pa);
236		if (s == 0) {
237			_kvm_err(kd, kd->program,
238			    "_i386_vatop: bootstrap data not in dump");
239			goto invalid;
240		} else
241			return (I386_PAGE_SIZE - offset);
242	}
243
244	pdeindex = va >> I386_PDRSHIFT;
245	pde = le32toh(PTD[pdeindex]);
246	if ((pde & I386_PG_V) == 0) {
247		_kvm_err(kd, kd->program, "_i386_vatop: pde not valid");
248		goto invalid;
249	}
250
251	if (pde & I386_PG_PS) {
252		/*
253		 * No second-level page table; ptd describes one 4MB
254		 * page.  (We assume that the kernel wouldn't set
255		 * PG_PS without enabling it cr0).
256		 */
257		offset = va & I386_PAGE_PS_MASK;
258		a = (pde & I386_PG_PS_FRAME) + offset;
259		s = _kvm_pa2off(kd, a, pa);
260		if (s == 0) {
261			_kvm_err(kd, kd->program,
262			    "_i386_vatop: 4MB page address not in dump");
263			goto invalid;
264		}
265		return (I386_NBPDR - offset);
266	}
267
268	pteindex = (va >> I386_PAGE_SHIFT) & (I386_NPTEPG - 1);
269	pte_pa = (pde & I386_PG_FRAME) + (pteindex * sizeof(pte));
270
271	s = _kvm_pa2off(kd, pte_pa, &ofs);
272	if (s < sizeof(pte)) {
273		_kvm_err(kd, kd->program, "_i386_vatop: pte_pa not found");
274		goto invalid;
275	}
276
277	/* XXX This has to be a physical address read, kvm_read is virtual */
278	if (pread(kd->pmfd, &pte, sizeof(pte), ofs) != sizeof(pte)) {
279		_kvm_syserr(kd, kd->program, "_i386_vatop: pread");
280		goto invalid;
281	}
282	pte = le32toh(pte);
283	if ((pte & I386_PG_V) == 0) {
284		_kvm_err(kd, kd->program, "_kvm_kvatop: pte not valid");
285		goto invalid;
286	}
287
288	a = (pte & I386_PG_FRAME) + offset;
289	s = _kvm_pa2off(kd, a, pa);
290	if (s == 0) {
291		_kvm_err(kd, kd->program, "_i386_vatop: address not in dump");
292		goto invalid;
293	} else
294		return (I386_PAGE_SIZE - offset);
295
296invalid:
297	_kvm_err(kd, 0, "invalid address (0x%jx)", (uintmax_t)va);
298	return (0);
299}
300
301static int
302_i386_vatop_pae(kvm_t *kd, kvaddr_t va, off_t *pa)
303{
304	struct vmstate *vm;
305	i386_physaddr_pae_t offset;
306	i386_physaddr_pae_t pte_pa;
307	i386_pde_pae_t pde;
308	i386_pte_pae_t pte;
309	kvaddr_t pdeindex;
310	kvaddr_t pteindex;
311	size_t s;
312	i386_physaddr_pae_t a;
313	off_t ofs;
314	i386_pde_pae_t *PTD;
315
316	vm = kd->vmst;
317	PTD = (i386_pde_pae_t *)vm->PTD;
318	offset = va & I386_PAGE_MASK;
319
320	/*
321	 * If we are initializing (kernel page table descriptor pointer
322	 * not yet set) then return pa == va to avoid infinite recursion.
323	 */
324	if (PTD == NULL) {
325		s = _kvm_pa2off(kd, va, pa);
326		if (s == 0) {
327			_kvm_err(kd, kd->program,
328			    "_i386_vatop_pae: bootstrap data not in dump");
329			goto invalid;
330		} else
331			return (I386_PAGE_SIZE - offset);
332	}
333
334	pdeindex = va >> I386_PDRSHIFT_PAE;
335	pde = le64toh(PTD[pdeindex]);
336	if ((pde & I386_PG_V) == 0) {
337		_kvm_err(kd, kd->program, "_kvm_kvatop_pae: pde not valid");
338		goto invalid;
339	}
340
341	if (pde & I386_PG_PS) {
342		/*
343		 * No second-level page table; ptd describes one 2MB
344		 * page.  (We assume that the kernel wouldn't set
345		 * PG_PS without enabling it cr0).
346		 */
347		offset = va & I386_PAGE_PS_MASK_PAE;
348		a = (pde & I386_PG_PS_FRAME_PAE) + offset;
349		s = _kvm_pa2off(kd, a, pa);
350		if (s == 0) {
351			_kvm_err(kd, kd->program,
352			    "_i386_vatop: 2MB page address not in dump");
353			goto invalid;
354		}
355		return (I386_NBPDR_PAE - offset);
356	}
357
358	pteindex = (va >> I386_PAGE_SHIFT) & (I386_NPTEPG_PAE - 1);
359	pte_pa = (pde & I386_PG_FRAME_PAE) + (pteindex * sizeof(pde));
360
361	s = _kvm_pa2off(kd, pte_pa, &ofs);
362	if (s < sizeof(pte)) {
363		_kvm_err(kd, kd->program, "_i386_vatop_pae: pdpe_pa not found");
364		goto invalid;
365	}
366
367	/* XXX This has to be a physical address read, kvm_read is virtual */
368	if (pread(kd->pmfd, &pte, sizeof(pte), ofs) != sizeof(pte)) {
369		_kvm_syserr(kd, kd->program, "_i386_vatop_pae: read");
370		goto invalid;
371	}
372	pte = le64toh(pte);
373	if ((pte & I386_PG_V) == 0) {
374		_kvm_err(kd, kd->program, "_i386_vatop_pae: pte not valid");
375		goto invalid;
376	}
377
378	a = (pte & I386_PG_FRAME_PAE) + offset;
379	s = _kvm_pa2off(kd, a, pa);
380	if (s == 0) {
381		_kvm_err(kd, kd->program,
382		    "_i386_vatop_pae: address not in dump");
383		goto invalid;
384	} else
385		return (I386_PAGE_SIZE - offset);
386
387invalid:
388	_kvm_err(kd, 0, "invalid address (0x%jx)", (uintmax_t)va);
389	return (0);
390}
391
392static int
393_i386_kvatop(kvm_t *kd, kvaddr_t va, off_t *pa)
394{
395
396	if (ISALIVE(kd)) {
397		_kvm_err(kd, 0, "vatop called in live kernel!");
398		return (0);
399	}
400	if (kd->vmst->pae)
401		return (_i386_vatop_pae(kd, va, pa));
402	else
403		return (_i386_vatop(kd, va, pa));
404}
405
406int
407_i386_native(kvm_t *kd __unused)
408{
409
410#ifdef __i386__
411	return (1);
412#else
413	return (0);
414#endif
415}
416
417static struct kvm_arch kvm_i386 = {
418	.ka_probe = _i386_probe,
419	.ka_initvtop = _i386_initvtop,
420	.ka_freevtop = _i386_freevtop,
421	.ka_kvatop = _i386_kvatop,
422	.ka_native = _i386_native,
423};
424
425KVM_ARCH(kvm_i386);
426