kvm_i386.c revision 82263
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 * 3. All advertising materials mentioning features or use of this software 18 * must display the following acknowledgement: 19 * This product includes software developed by the University of 20 * California, Berkeley and its contributors. 21 * 4. Neither the name of the University nor the names of its contributors 22 * may be used to endorse or promote products derived from this software 23 * without specific prior written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 28 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 35 * SUCH DAMAGE. 36 */ 37 38#if defined(LIBC_SCCS) && !defined(lint) 39#if 0 40static char sccsid[] = "@(#)kvm_hp300.c 8.1 (Berkeley) 6/4/93"; 41#else 42static const char rcsid[] = 43 "$FreeBSD: head/lib/libkvm/kvm_i386.c 82263 2001-08-24 08:53:30Z peter $"; 44#endif 45#endif /* LIBC_SCCS and not lint */ 46 47/* 48 * i386 machine dependent routines for kvm. Hopefully, the forthcoming 49 * vm code will one day obsolete this module. 50 */ 51 52#include <sys/param.h> 53#include <sys/lock.h> 54#include <sys/mutex.h> 55#include <sys/user.h> 56#include <sys/proc.h> 57#include <sys/stat.h> 58#include <stdlib.h> 59#include <unistd.h> 60#include <nlist.h> 61#include <kvm.h> 62 63#include <vm/vm.h> 64#include <vm/vm_param.h> 65 66#include <limits.h> 67 68#include "kvm_private.h" 69 70#ifndef btop 71#define btop(x) (i386_btop(x)) 72#define ptob(x) (i386_ptob(x)) 73#endif 74 75struct vmstate { 76 pd_entry_t *PTD; 77}; 78 79void 80_kvm_freevtop(kvm_t *kd) 81{ 82 if (kd->vmst != 0) { 83 if (kd->vmst->PTD) { 84 free(kd->vmst->PTD); 85 } 86 free(kd->vmst); 87 } 88} 89 90int 91_kvm_initvtop(kvm_t *kd) 92{ 93 struct vmstate *vm; 94 struct nlist nlist[2]; 95 u_long pa; 96 u_long kernbase; 97 pd_entry_t *PTD; 98 99 vm = (struct vmstate *)_kvm_malloc(kd, sizeof(*vm)); 100 if (vm == 0) { 101 _kvm_err(kd, kd->program, "cannot allocate vm"); 102 return (-1); 103 } 104 kd->vmst = vm; 105 vm->PTD = 0; 106 107 nlist[0].n_name = "kernbase"; 108 nlist[1].n_name = 0; 109 110 if (kvm_nlist(kd, nlist) != 0) 111 kernbase = KERNBASE; /* for old kernels */ 112 else 113 kernbase = nlist[0].n_value; 114 115 nlist[0].n_name = "IdlePTD"; 116 nlist[1].n_name = 0; 117 118 if (kvm_nlist(kd, nlist) != 0) { 119 _kvm_err(kd, kd->program, "bad namelist"); 120 return (-1); 121 } 122 if (kvm_read(kd, (nlist[0].n_value - kernbase), &pa, sizeof(pa)) != 123 sizeof(pa)) { 124 _kvm_err(kd, kd->program, "cannot read IdlePTD"); 125 return (-1); 126 } 127 PTD = _kvm_malloc(kd, PAGE_SIZE); 128 if (kvm_read(kd, pa, PTD, PAGE_SIZE) != PAGE_SIZE) { 129 _kvm_err(kd, kd->program, "cannot read PTD"); 130 return (-1); 131 } 132 vm->PTD = PTD; 133 return (0); 134} 135 136static int 137_kvm_vatop(kvm_t *kd, u_long va, u_long *pa) 138{ 139 struct vmstate *vm; 140 u_long offset; 141 u_long pte_pa; 142 pd_entry_t pde; 143 pt_entry_t pte; 144 u_long pdeindex; 145 u_long pteindex; 146 int i; 147 148 if (ISALIVE(kd)) { 149 _kvm_err(kd, 0, "vatop called in live kernel!"); 150 return((off_t)0); 151 } 152 153 vm = kd->vmst; 154 offset = va & (PAGE_SIZE - 1); 155 156 /* 157 * If we are initializing (kernel page table descriptor pointer 158 * not yet set) then return pa == va to avoid infinite recursion. 159 */ 160 if (vm->PTD == 0) { 161 *pa = va; 162 return (PAGE_SIZE - offset); 163 } 164 165 pdeindex = va >> PDRSHIFT; 166 pde = vm->PTD[pdeindex]; 167 if (((u_long)pde & PG_V) == 0) 168 goto invalid; 169 170 if ((u_long)pde & PG_PS) { 171 /* 172 * No second-level page table; ptd describes one 4MB page. 173 * (We assume that the kernel wouldn't set PG_PS without enabling 174 * it cr0, and that the kernel doesn't support 36-bit physical 175 * addresses). 176 */ 177#define PAGE4M_MASK (NBPDR - 1) 178#define PG_FRAME4M (~PAGE4M_MASK) 179 *pa = ((u_long)pde & PG_FRAME4M) + (va & PAGE4M_MASK); 180 return (NBPDR - (va & PAGE4M_MASK)); 181 } 182 183 pteindex = (va >> PAGE_SHIFT) & (NPTEPG-1); 184 pte_pa = ((u_long)pde & PG_FRAME) + (pteindex * sizeof(pt_entry_t)); 185 186 /* XXX This has to be a physical address read, kvm_read is virtual */ 187 if (lseek(kd->pmfd, pte_pa, 0) == -1) { 188 _kvm_syserr(kd, kd->program, "_kvm_vatop: lseek"); 189 goto invalid; 190 } 191 if (read(kd->pmfd, &pte, sizeof pte) != sizeof pte) { 192 _kvm_syserr(kd, kd->program, "_kvm_vatop: read"); 193 goto invalid; 194 } 195 if (((u_long)pte & PG_V) == 0) 196 goto invalid; 197 198 *pa = ((u_long)pte & PG_FRAME) + offset; 199 return (PAGE_SIZE - offset); 200 201invalid: 202 _kvm_err(kd, 0, "invalid address (%x)", va); 203 return (0); 204} 205 206int 207_kvm_kvatop(kvm_t *kd, u_long va, u_long *pa) 208{ 209 return (_kvm_vatop(kd, va, pa)); 210} 211