kvm_ia64.c revision 217744 
1137587Snik/* $FreeBSD: head/lib/libkvm/kvm_ia64.c 217744 2011-01-23 11:08:28Z uqs $ */
2137587Snik/*	$NetBSD: kvm_alpha.c,v 1.7.2.1 1997/11/02 20:34:26 mellon Exp $	*/
3137587Snik
4137587Snik/*
5137587Snik * Copyright (c) 1994, 1995 Carnegie-Mellon University.
6137587Snik * All rights reserved.
7137587Snik *
8137587Snik * Author: Chris G. Demetriou
9137587Snik *
10137587Snik * 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/atomic.h>
36#include <machine/pte.h>
37
38#include <kvm.h>
39#include <limits.h>
40#include <stdlib.h>
41#include <unistd.h>
42
43#include "kvm_private.h"
44
45#define	REGION_BASE(n)		(((uint64_t)(n)) << 61)
46#define	REGION_ADDR(x)		((x) & ((1LL<<61)-1LL))
47
48#define	NKPTEPG(ps)		((ps) / sizeof(struct ia64_lpte))
49#define	NKPTEDIR(ps)		((ps) >> 3)
50#define	KPTE_PTE_INDEX(va,ps)	(((va)/(ps)) % NKPTEPG(ps))
51#define	KPTE_DIR0_INDEX(va,ps)	((((va)/(ps)) / NKPTEPG(ps)) / NKPTEDIR(ps))
52#define	KPTE_DIR1_INDEX(va,ps)	((((va)/(ps)) / NKPTEPG(ps)) % NKPTEDIR(ps))
53
54struct vmstate {
55	void	*mmapbase;
56	size_t	mmapsize;
57	size_t	pagesize;
58	u_long	kptdir;
59};
60
61/*
62 * Map the ELF headers into the process' address space. We do this in two
63 * steps: first the ELF header itself and using that information the whole
64 * set of headers.
65 */
66static int
67_kvm_maphdrs(kvm_t *kd, size_t sz)
68{
69	struct vmstate *vm = kd->vmst;
70
71	/* munmap() previous mmap(). */
72	if (vm->mmapbase != NULL) {
73		munmap(vm->mmapbase, vm->mmapsize);
74		vm->mmapbase = NULL;
75	}
76
77	vm->mmapsize = sz;
78	vm->mmapbase = mmap(NULL, sz, PROT_READ, MAP_PRIVATE, kd->pmfd, 0);
79	if (vm->mmapbase == MAP_FAILED) {
80		_kvm_err(kd, kd->program, "cannot mmap corefile");
81		return (-1);
82	}
83
84	return (0);
85}
86
87/*
88 * Translate a physical memory address to a file-offset in the crash-dump.
89 */
90static size_t
91_kvm_pa2off(kvm_t *kd, uint64_t pa, off_t *ofs, size_t pgsz)
92{
93	Elf64_Ehdr *e = kd->vmst->mmapbase;
94	Elf64_Phdr *p = (Elf64_Phdr*)((char*)e + e->e_phoff);
95	int n = e->e_phnum;
96
97	if (pa != REGION_ADDR(pa)) {
98		_kvm_err(kd, kd->program, "internal error");
99		return (0);
100	}
101
102	while (n && (pa < p->p_paddr || pa >= p->p_paddr + p->p_memsz))
103		p++, n--;
104	if (n == 0)
105		return (0);
106
107	*ofs = (pa - p->p_paddr) + p->p_offset;
108	if (pgsz == 0)
109		return (p->p_memsz - (pa - p->p_paddr));
110	return (pgsz - ((size_t)pa & (pgsz - 1)));
111}
112
113void
114_kvm_freevtop(kvm_t *kd)
115{
116	struct vmstate *vm = kd->vmst;
117
118	if (vm->mmapbase != NULL)
119		munmap(vm->mmapbase, vm->mmapsize);
120	free(vm);
121	kd->vmst = NULL;
122}
123
124int
125_kvm_initvtop(kvm_t *kd)
126{
127	struct nlist nl[2];
128	uint64_t va;
129	Elf64_Ehdr *ehdr;
130	size_t hdrsz;
131
132	kd->vmst = (struct vmstate *)_kvm_malloc(kd, sizeof(*kd->vmst));
133	if (kd->vmst == NULL) {
134		_kvm_err(kd, kd->program, "cannot allocate vm");
135		return (-1);
136	}
137
138	kd->vmst->pagesize = getpagesize();
139
140	if (_kvm_maphdrs(kd, sizeof(Elf64_Ehdr)) == -1)
141		return (-1);
142
143	ehdr = kd->vmst->mmapbase;
144	hdrsz = ehdr->e_phoff + ehdr->e_phentsize * ehdr->e_phnum;
145	if (_kvm_maphdrs(kd, hdrsz) == -1)
146		return (-1);
147
148	/*
149	 * At this point we've got enough information to use kvm_read() for
150	 * direct mapped (ie region 6 and region 7) address, such as symbol
151	 * addresses/values.
152	 */
153
154	nl[0].n_name = "ia64_kptdir";
155	nl[1].n_name = 0;
156
157	if (kvm_nlist(kd, nl) != 0) {
158		_kvm_err(kd, kd->program, "bad namelist");
159		return (-1);
160	}
161
162	if (kvm_read(kd, (nl[0].n_value), &va, sizeof(va)) != sizeof(va)) {
163		_kvm_err(kd, kd->program, "cannot read kptdir");
164		return (-1);
165	}
166
167	if (va < REGION_BASE(6)) {
168		_kvm_err(kd, kd->program, "kptdir is itself virtual");
169		return (-1);
170	}
171
172	kd->vmst->kptdir = va;
173	return (0);
174}
175
176int
177_kvm_kvatop(kvm_t *kd, u_long va, off_t *pa)
178{
179	struct ia64_lpte pte;
180	uint64_t pgaddr, pt0addr, pt1addr;
181	size_t pgno, pgsz, pt0no, pt1no;
182
183	if (va >= REGION_BASE(6)) {
184		/* Regions 6 and 7: direct mapped. */
185		return (_kvm_pa2off(kd, REGION_ADDR(va), pa, 0));
186	} else if (va >= REGION_BASE(5)) {
187		/* Region 5: virtual. */
188		va = REGION_ADDR(va);
189		pgsz = kd->vmst->pagesize;
190		pt0no = KPTE_DIR0_INDEX(va, pgsz);
191		pt1no = KPTE_DIR1_INDEX(va, pgsz);
192		pgno = KPTE_PTE_INDEX(va, pgsz);
193		if (pt0no >= NKPTEDIR(pgsz))
194			goto fail;
195		pt0addr = kd->vmst->kptdir + (pt0no << 3);
196		if (kvm_read(kd, pt0addr, &pt1addr, 8) != 8)
197			goto fail;
198		if (pt1addr == 0)
199			goto fail;
200		pt1addr += pt1no << 3;
201		if (kvm_read(kd, pt1addr, &pgaddr, 8) != 8)
202			goto fail;
203		if (pgaddr == 0)
204			goto fail;
205		pgaddr += pgno * sizeof(pte);
206		if (kvm_read(kd, pgaddr, &pte, sizeof(pte)) != sizeof(pte))
207			goto fail;
208		if (!(pte.pte & PTE_PRESENT))
209			goto fail;
210		va = (pte.pte & PTE_PPN_MASK) + (va & (pgsz - 1));
211		return (_kvm_pa2off(kd, va, pa, pgsz));
212	}
213
214 fail:
215	_kvm_err(kd, kd->program, "invalid kernel virtual address");
216	*pa = ~0UL;
217	return (0);
218}
219