kvm_ia64.c revision 169760 
1/* $FreeBSD: head/lib/libkvm/kvm_ia64.c 169760 2007-05-19 13:11:27Z marcel $ */
2/*	$NetBSD: kvm_alpha.c,v 1.7.2.1 1997/11/02 20:34:26 mellon Exp $	*/
3
4/*
5 * Copyright (c) 1994, 1995 Carnegie-Mellon University.
6 * All rights reserved.
7 *
8 * Author: Chris G. Demetriou
9 *
10 * Permission to use, copy, modify and distribute this software and
11 * its documentation is hereby granted, provided that both the copyright
12 * notice and this permission notice appear in all copies of the
13 * software, derivative works or modified versions, and any portions
14 * thereof, and that both notices appear in supporting documentation.
15 *
16 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
17 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
18 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
19 *
20 * Carnegie Mellon requests users of this software to return to
21 *
22 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
23 *  School of Computer Science
24 *  Carnegie Mellon University
25 *  Pittsburgh PA 15213-3890
26 *
27 * any improvements or extensions that they make and grant Carnegie the
28 * rights to redistribute these changes.
29 */
30
31#include <sys/types.h>
32#include <sys/elf64.h>
33#include <sys/mman.h>
34
35#include <machine/pte.h>
36
37#include <kvm.h>
38#include <limits.h>
39#include <stdlib.h>
40#include <unistd.h>
41
42#include "kvm_private.h"
43
44#define	REGION_BASE(n)		(((uint64_t)(n)) << 61)
45#define	REGION_ADDR(x)		((x) & ((1LL<<61)-1LL))
46
47#define	NKPTEPG(ps)		((ps) / sizeof(struct ia64_lpte))
48#define	NKPTEDIR(ps)		((ps) >> 3)
49#define	KPTE_PTE_INDEX(va,ps)	(((va)/(ps)) % NKPTEPG(ps))
50#define	KPTE_DIR0_INDEX(va,ps)	((((va)/(ps)) / NKPTEPG(ps)) / NKPTEDIR(ps))
51#define	KPTE_DIR1_INDEX(va,ps)	((((va)/(ps)) / NKPTEPG(ps)) % NKPTEDIR(ps))
52
53struct vmstate {
54	void	*mmapbase;
55	size_t	mmapsize;
56	size_t	pagesize;
57	u_long	kptdir;
58};
59
60/*
61 * Map the ELF headers into the process' address space. We do this in two
62 * steps: first the ELF header itself and using that information the whole
63 * set of headers.
64 */
65static int
66_kvm_maphdrs(kvm_t *kd, size_t sz)
67{
68	struct vmstate *vm = kd->vmst;
69
70	/* munmap() previous mmap(). */
71	if (vm->mmapbase != NULL) {
72		munmap(vm->mmapbase, vm->mmapsize);
73		vm->mmapbase = NULL;
74	}
75
76	vm->mmapsize = sz;
77	vm->mmapbase = mmap(NULL, sz, PROT_READ, MAP_PRIVATE, kd->pmfd, 0);
78	if (vm->mmapbase == MAP_FAILED) {
79		_kvm_err(kd, kd->program, "cannot mmap corefile");
80		return (-1);
81	}
82
83	return (0);
84}
85
86/*
87 * Translate a physical memory address to a file-offset in the crash-dump.
88 */
89static size_t
90_kvm_pa2off(kvm_t *kd, uint64_t pa, off_t *ofs, size_t pgsz)
91{
92	Elf64_Ehdr *e = kd->vmst->mmapbase;
93	Elf64_Phdr *p = (Elf64_Phdr*)((char*)e + e->e_phoff);
94	int n = e->e_phnum;
95
96	if (pa != REGION_ADDR(pa)) {
97		_kvm_err(kd, kd->program, "internal error");
98		return (0);
99	}
100
101	while (n && (pa < p->p_paddr || pa >= p->p_paddr + p->p_memsz))
102		p++, n--;
103	if (n == 0)
104		return (0);
105
106	*ofs = (pa - p->p_paddr) + p->p_offset;
107	if (pgsz == 0)
108		return (p->p_memsz - (pa - p->p_paddr));
109	return (pgsz - ((size_t)pa & (pgsz - 1)));
110}
111
112void
113_kvm_freevtop(kvm_t *kd)
114{
115	struct vmstate *vm = kd->vmst;
116
117	if (vm->mmapbase != NULL)
118		munmap(vm->mmapbase, vm->mmapsize);
119	free(vm);
120	kd->vmst = NULL;
121}
122
123int
124_kvm_initvtop(kvm_t *kd)
125{
126	struct nlist nlist[2];
127	uint64_t va;
128	Elf64_Ehdr *ehdr;
129	size_t hdrsz;
130
131	kd->vmst = (struct vmstate *)_kvm_malloc(kd, sizeof(*kd->vmst));
132	if (kd->vmst == NULL) {
133		_kvm_err(kd, kd->program, "cannot allocate vm");
134		return (-1);
135	}
136
137	kd->vmst->pagesize = getpagesize();
138
139	if (_kvm_maphdrs(kd, sizeof(Elf64_Ehdr)) == -1)
140		return (-1);
141
142	ehdr = kd->vmst->mmapbase;
143	hdrsz = ehdr->e_phoff + ehdr->e_phentsize * ehdr->e_phnum;
144	if (_kvm_maphdrs(kd, hdrsz) == -1)
145		return (-1);
146
147	/*
148	 * At this point we've got enough information to use kvm_read() for
149	 * direct mapped (ie region 6 and region 7) address, such as symbol
150	 * addresses/values.
151	 */
152
153	nlist[0].n_name = "ia64_kptdir";
154	nlist[1].n_name = 0;
155
156	if (kvm_nlist(kd, nlist) != 0) {
157		_kvm_err(kd, kd->program, "bad namelist");
158		return (-1);
159	}
160
161	if (kvm_read(kd, (nlist[0].n_value), &va, sizeof(va)) != sizeof(va)) {
162		_kvm_err(kd, kd->program, "cannot read kptdir");
163		return (-1);
164	}
165
166	if (va < REGION_BASE(6)) {
167		_kvm_err(kd, kd->program, "kptdir is itself virtual");
168		return (-1);
169	}
170
171	kd->vmst->kptdir = va;
172	return (0);
173}
174
175int
176_kvm_kvatop(kvm_t *kd, u_long va, off_t *pa)
177{
178	struct ia64_lpte pte;
179	uint64_t pgaddr, pt0addr, pt1addr;
180	size_t pgno, pgsz, pt0no, pt1no;
181
182	if (va >= REGION_BASE(6)) {
183		/* Regions 6 and 7: direct mapped. */
184		return (_kvm_pa2off(kd, REGION_ADDR(va), pa, 0));
185	} else if (va >= REGION_BASE(5)) {
186		/* Region 5: virtual. */
187		va = REGION_ADDR(va);
188		pgsz = kd->vmst->pagesize;
189		pt0no = KPTE_DIR0_INDEX(va, pgsz);
190		pt1no = KPTE_DIR1_INDEX(va, pgsz);
191		pgno = KPTE_PTE_INDEX(va, pgsz);
192		if (pt0no >= NKPTEDIR(pgsz))
193			goto fail;
194		pt0addr = kd->vmst->kptdir + (pt0no << 3);
195		if (kvm_read(kd, pt0addr, &pt1addr, 8) != 8)
196			goto fail;
197		if (pt1addr == 0)
198			goto fail;
199		pt1addr += pt1no << 3;
200		if (kvm_read(kd, pt1addr, &pgaddr, 8) != 8)
201			goto fail;
202		if (pgaddr == 0)
203			goto fail;
204		pgaddr += pgno * sizeof(pte);
205		if (kvm_read(kd, pgaddr, &pte, sizeof(pte)) != sizeof(pte))
206			goto fail;
207		if (!(pte.pte & PTE_PRESENT))
208			goto fail;
209		va = (pte.pte & PTE_PPN_MASK) + (va & (pgsz - 1));
210		return (_kvm_pa2off(kd, va, pa, pgsz));
211	}
212
213 fail:
214	_kvm_err(kd, kd->program, "invalid kernel virtual address");
215	*pa = ~0UL;
216	return (0);
217}
218