1/*-
2 * Copyright (c) 1989, 1992, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * This code is derived from software developed by the Computer Systems
6 * Engineering group at Lawrence Berkeley Laboratory under DARPA contract
7 * BG 91-66 and contributed to Berkeley.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 *    notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 *    notice, this list of conditions and the following disclaimer in the
16 *    documentation and/or other materials provided with the distribution.
17 * 4. Neither the name of the University nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34#include <sys/cdefs.h>
35__FBSDID("$FreeBSD$");
36
37#if defined(LIBC_SCCS) && !defined(lint)
38#if 0
39static char sccsid[] = "@(#)kvm_hp300.c	8.1 (Berkeley) 6/4/93";
40#endif
41#endif /* LIBC_SCCS and not lint */
42
43/*
44 * i386 machine dependent routines for kvm.  Hopefully, the forthcoming
45 * vm code will one day obsolete this module.
46 */
47
48#include <sys/param.h>
49#include <sys/user.h>
50#include <sys/proc.h>
51#include <sys/stat.h>
52#include <sys/mman.h>
53#include <stdlib.h>
54#include <string.h>
55#include <unistd.h>
56#include <nlist.h>
57#include <kvm.h>
58
59#include <vm/vm.h>
60#include <vm/vm_param.h>
61
62#include <machine/elf.h>
63
64#include <limits.h>
65
66#include "kvm_private.h"
67
68#ifndef btop
69#define	btop(x)		(i386_btop(x))
70#define	ptob(x)		(i386_ptob(x))
71#endif
72
73#define	PG_FRAME_PAE	(~((uint64_t)PAGE_MASK))
74#define	PDRSHIFT_PAE	21
75#define	NPTEPG_PAE	(PAGE_SIZE/sizeof(uint64_t))
76#define	NBPDR_PAE	(1<<PDRSHIFT_PAE)
77
78/* minidump must be the first item! */
79struct vmstate {
80	int		minidump;	/* 1 = minidump mode */
81	void		*mmapbase;
82	size_t		mmapsize;
83	void		*PTD;
84	int		pae;
85};
86
87/*
88 * Map the ELF headers into the process' address space. We do this in two
89 * steps: first the ELF header itself and using that information the whole
90 * set of headers. (Taken from kvm_ia64.c)
91 */
92static int
93_kvm_maphdrs(kvm_t *kd, size_t sz)
94{
95	struct vmstate *vm = kd->vmst;
96
97	/* munmap() previous mmap(). */
98	if (vm->mmapbase != NULL) {
99		munmap(vm->mmapbase, vm->mmapsize);
100		vm->mmapbase = NULL;
101	}
102
103	vm->mmapsize = sz;
104	vm->mmapbase = mmap(NULL, sz, PROT_READ, MAP_PRIVATE, kd->pmfd, 0);
105	if (vm->mmapbase == MAP_FAILED) {
106		_kvm_err(kd, kd->program, "cannot mmap corefile");
107		return (-1);
108	}
109	return (0);
110}
111
112/*
113 * Translate a physical memory address to a file-offset in the crash-dump.
114 * (Taken from kvm_ia64.c)
115 */
116static size_t
117_kvm_pa2off(kvm_t *kd, uint64_t pa, off_t *ofs)
118{
119	Elf_Ehdr *e = kd->vmst->mmapbase;
120	Elf_Phdr *p;
121	int n;
122
123	if (kd->rawdump) {
124		*ofs = pa;
125		return (PAGE_SIZE - ((size_t)pa & PAGE_MASK));
126	}
127
128	p = (Elf_Phdr*)((char*)e + e->e_phoff);
129	n = e->e_phnum;
130	while (n && (pa < p->p_paddr || pa >= p->p_paddr + p->p_memsz))
131		p++, n--;
132	if (n == 0)
133		return (0);
134	*ofs = (pa - p->p_paddr) + p->p_offset;
135	return (PAGE_SIZE - ((size_t)pa & PAGE_MASK));
136}
137
138void
139_kvm_freevtop(kvm_t *kd)
140{
141	struct vmstate *vm = kd->vmst;
142
143	if (kd->vmst->minidump)
144		return (_kvm_minidump_freevtop(kd));
145	if (vm->mmapbase != NULL)
146		munmap(vm->mmapbase, vm->mmapsize);
147	if (vm->PTD)
148		free(vm->PTD);
149	free(vm);
150	kd->vmst = NULL;
151}
152
153int
154_kvm_initvtop(kvm_t *kd)
155{
156	struct nlist nl[2];
157	u_long pa;
158	u_long kernbase;
159	char		*PTD;
160	Elf_Ehdr	*ehdr;
161	size_t		hdrsz;
162	int		i;
163	char		minihdr[8];
164
165	if (!kd->rawdump && pread(kd->pmfd, &minihdr, 8, 0) == 8)
166		if (memcmp(&minihdr, "minidump", 8) == 0)
167			return (_kvm_minidump_initvtop(kd));
168
169	kd->vmst = (struct vmstate *)_kvm_malloc(kd, sizeof(*kd->vmst));
170	if (kd->vmst == 0) {
171		_kvm_err(kd, kd->program, "cannot allocate vm");
172		return (-1);
173	}
174	kd->vmst->PTD = 0;
175
176	if (kd->rawdump == 0) {
177		if (_kvm_maphdrs(kd, sizeof(Elf_Ehdr)) == -1)
178			return (-1);
179
180		ehdr = kd->vmst->mmapbase;
181		hdrsz = ehdr->e_phoff + ehdr->e_phentsize * ehdr->e_phnum;
182		if (_kvm_maphdrs(kd, hdrsz) == -1)
183			return (-1);
184	}
185
186	nl[0].n_name = "kernbase";
187	nl[1].n_name = 0;
188
189	if (kvm_nlist(kd, nl) != 0)
190		kernbase = KERNBASE;	/* for old kernels */
191	else
192		kernbase = nl[0].n_value;
193
194	nl[0].n_name = "IdlePDPT";
195	nl[1].n_name = 0;
196
197	if (kvm_nlist(kd, nl) == 0) {
198		uint64_t pa64;
199
200		if (kvm_read(kd, (nl[0].n_value - kernbase), &pa,
201		    sizeof(pa)) != sizeof(pa)) {
202			_kvm_err(kd, kd->program, "cannot read IdlePDPT");
203			return (-1);
204		}
205		PTD = _kvm_malloc(kd, 4 * PAGE_SIZE);
206		for (i = 0; i < 4; i++) {
207			if (kvm_read(kd, pa + (i * sizeof(pa64)), &pa64,
208			    sizeof(pa64)) != sizeof(pa64)) {
209				_kvm_err(kd, kd->program, "Cannot read PDPT");
210				free(PTD);
211				return (-1);
212			}
213			if (kvm_read(kd, pa64 & PG_FRAME_PAE,
214			    PTD + (i * PAGE_SIZE), PAGE_SIZE) != (PAGE_SIZE)) {
215				_kvm_err(kd, kd->program, "cannot read PDPT");
216				free(PTD);
217				return (-1);
218			}
219		}
220		kd->vmst->PTD = PTD;
221		kd->vmst->pae = 1;
222	} else {
223		nl[0].n_name = "IdlePTD";
224		nl[1].n_name = 0;
225
226		if (kvm_nlist(kd, nl) != 0) {
227			_kvm_err(kd, kd->program, "bad namelist");
228			return (-1);
229		}
230		if (kvm_read(kd, (nl[0].n_value - kernbase), &pa,
231		    sizeof(pa)) != sizeof(pa)) {
232			_kvm_err(kd, kd->program, "cannot read IdlePTD");
233			return (-1);
234		}
235		PTD = _kvm_malloc(kd, PAGE_SIZE);
236		if (kvm_read(kd, pa, PTD, PAGE_SIZE) != PAGE_SIZE) {
237			_kvm_err(kd, kd->program, "cannot read PTD");
238			return (-1);
239		}
240		kd->vmst->PTD = PTD;
241		kd->vmst->pae = 0;
242	}
243	return (0);
244}
245
246static int
247_kvm_vatop(kvm_t *kd, u_long va, off_t *pa)
248{
249	struct vmstate *vm;
250	u_long offset;
251	u_long pte_pa;
252	u_long pde_pa;
253	pd_entry_t pde;
254	pt_entry_t pte;
255	u_long pdeindex;
256	u_long pteindex;
257	size_t s;
258	u_long a;
259	off_t ofs;
260	uint32_t *PTD;
261
262	vm = kd->vmst;
263	PTD = (uint32_t *)vm->PTD;
264	offset = va & (PAGE_SIZE - 1);
265
266	/*
267	 * If we are initializing (kernel page table descriptor pointer
268	 * not yet set) then return pa == va to avoid infinite recursion.
269	 */
270	if (PTD == 0) {
271		s = _kvm_pa2off(kd, va, pa);
272		if (s == 0) {
273			_kvm_err(kd, kd->program,
274			    "_kvm_vatop: bootstrap data not in dump");
275			goto invalid;
276		} else
277			return (PAGE_SIZE - offset);
278	}
279
280	pdeindex = va >> PDRSHIFT;
281	pde = PTD[pdeindex];
282	if (((u_long)pde & PG_V) == 0) {
283		_kvm_err(kd, kd->program, "_kvm_vatop: pde not valid");
284		goto invalid;
285	}
286
287	if ((u_long)pde & PG_PS) {
288	      /*
289	       * No second-level page table; ptd describes one 4MB page.
290	       * (We assume that the kernel wouldn't set PG_PS without enabling
291	       * it cr0).
292	       */
293#define	PAGE4M_MASK	(NBPDR - 1)
294#define	PG_FRAME4M	(~PAGE4M_MASK)
295		pde_pa = ((u_long)pde & PG_FRAME4M) + (va & PAGE4M_MASK);
296		s = _kvm_pa2off(kd, pde_pa, &ofs);
297		if (s == 0) {
298			_kvm_err(kd, kd->program,
299			    "_kvm_vatop: 4MB page address not in dump");
300			goto invalid;
301		}
302		*pa = ofs;
303		return (NBPDR - (va & PAGE4M_MASK));
304	}
305
306	pteindex = (va >> PAGE_SHIFT) & (NPTEPG-1);
307	pte_pa = ((u_long)pde & PG_FRAME) + (pteindex * sizeof(pde));
308
309	s = _kvm_pa2off(kd, pte_pa, &ofs);
310	if (s < sizeof pte) {
311		_kvm_err(kd, kd->program, "_kvm_vatop: pdpe_pa not found");
312		goto invalid;
313	}
314
315	/* XXX This has to be a physical address read, kvm_read is virtual */
316	if (lseek(kd->pmfd, ofs, 0) == -1) {
317		_kvm_syserr(kd, kd->program, "_kvm_vatop: lseek");
318		goto invalid;
319	}
320	if (read(kd->pmfd, &pte, sizeof pte) != sizeof pte) {
321		_kvm_syserr(kd, kd->program, "_kvm_vatop: read");
322		goto invalid;
323	}
324	if (((u_long)pte & PG_V) == 0) {
325		_kvm_err(kd, kd->program, "_kvm_kvatop: pte not valid");
326		goto invalid;
327	}
328
329	a = ((u_long)pte & PG_FRAME) + offset;
330	s =_kvm_pa2off(kd, a, pa);
331	if (s == 0) {
332		_kvm_err(kd, kd->program, "_kvm_vatop: address not in dump");
333		goto invalid;
334	} else
335		return (PAGE_SIZE - offset);
336
337invalid:
338	_kvm_err(kd, 0, "invalid address (0x%lx)", va);
339	return (0);
340}
341
342static int
343_kvm_vatop_pae(kvm_t *kd, u_long va, off_t *pa)
344{
345	struct vmstate *vm;
346	uint64_t offset;
347	uint64_t pte_pa;
348	uint64_t pde_pa;
349	uint64_t pde;
350	uint64_t pte;
351	u_long pdeindex;
352	u_long pteindex;
353	size_t s;
354	uint64_t a;
355	off_t ofs;
356	uint64_t *PTD;
357
358	vm = kd->vmst;
359	PTD = (uint64_t *)vm->PTD;
360	offset = va & (PAGE_SIZE - 1);
361
362	/*
363	 * If we are initializing (kernel page table descriptor pointer
364	 * not yet set) then return pa == va to avoid infinite recursion.
365	 */
366	if (PTD == 0) {
367		s = _kvm_pa2off(kd, va, pa);
368		if (s == 0) {
369			_kvm_err(kd, kd->program,
370			    "_kvm_vatop_pae: bootstrap data not in dump");
371			goto invalid;
372		} else
373			return (PAGE_SIZE - offset);
374	}
375
376	pdeindex = va >> PDRSHIFT_PAE;
377	pde = PTD[pdeindex];
378	if (((u_long)pde & PG_V) == 0) {
379		_kvm_err(kd, kd->program, "_kvm_kvatop_pae: pde not valid");
380		goto invalid;
381	}
382
383	if ((u_long)pde & PG_PS) {
384	      /*
385	       * No second-level page table; ptd describes one 2MB page.
386	       * (We assume that the kernel wouldn't set PG_PS without enabling
387	       * it cr0).
388	       */
389#define	PAGE2M_MASK	(NBPDR_PAE - 1)
390#define	PG_FRAME2M	(~PAGE2M_MASK)
391		pde_pa = ((u_long)pde & PG_FRAME2M) + (va & PAGE2M_MASK);
392		s = _kvm_pa2off(kd, pde_pa, &ofs);
393		if (s == 0) {
394			_kvm_err(kd, kd->program,
395			    "_kvm_vatop: 2MB page address not in dump");
396			goto invalid;
397		}
398		*pa = ofs;
399		return (NBPDR_PAE - (va & PAGE2M_MASK));
400	}
401
402	pteindex = (va >> PAGE_SHIFT) & (NPTEPG_PAE-1);
403	pte_pa = ((uint64_t)pde & PG_FRAME_PAE) + (pteindex * sizeof(pde));
404
405	s = _kvm_pa2off(kd, pte_pa, &ofs);
406	if (s < sizeof pte) {
407		_kvm_err(kd, kd->program, "_kvm_vatop_pae: pdpe_pa not found");
408		goto invalid;
409	}
410
411	/* XXX This has to be a physical address read, kvm_read is virtual */
412	if (lseek(kd->pmfd, ofs, 0) == -1) {
413		_kvm_syserr(kd, kd->program, "_kvm_vatop_pae: lseek");
414		goto invalid;
415	}
416	if (read(kd->pmfd, &pte, sizeof pte) != sizeof pte) {
417		_kvm_syserr(kd, kd->program, "_kvm_vatop_pae: read");
418		goto invalid;
419	}
420	if (((uint64_t)pte & PG_V) == 0) {
421		_kvm_err(kd, kd->program, "_kvm_vatop_pae: pte not valid");
422		goto invalid;
423	}
424
425	a = ((uint64_t)pte & PG_FRAME_PAE) + offset;
426	s =_kvm_pa2off(kd, a, pa);
427	if (s == 0) {
428		_kvm_err(kd, kd->program,
429		    "_kvm_vatop_pae: address not in dump");
430		goto invalid;
431	} else
432		return (PAGE_SIZE - offset);
433
434invalid:
435	_kvm_err(kd, 0, "invalid address (0x%lx)", va);
436	return (0);
437}
438
439int
440_kvm_kvatop(kvm_t *kd, u_long va, off_t *pa)
441{
442
443	if (kd->vmst->minidump)
444		return (_kvm_minidump_kvatop(kd, va, pa));
445	if (ISALIVE(kd)) {
446		_kvm_err(kd, 0, "vatop called in live kernel!");
447		return (0);
448	}
449	if (kd->vmst->pae)
450		return (_kvm_vatop_pae(kd, va, pa));
451	else
452		return (_kvm_vatop(kd, va, pa));
453}
454