1 /* $OpenBSD: kvm_i386.c,v 1.28 2021/12/01 16:53:28 deraadt Exp $ */ 2 /* $NetBSD: kvm_i386.c,v 1.9 1996/03/18 22:33:38 thorpej Exp $ */ 3 4 /*- 5 * Copyright (c) 1989, 1992, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * This code is derived from software developed by the Computer Systems 9 * Engineering group at Lawrence Berkeley Laboratory under DARPA contract 10 * BG 91-66 and contributed to Berkeley. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 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/types.h> 43 #include <sys/signal.h> 44 #include <sys/proc.h> 45 #include <sys/stat.h> 46 #include <stdlib.h> 47 #include <unistd.h> 48 #include <nlist.h> 49 #include <kvm.h> 50 51 #include <uvm/uvm_extern.h> 52 #include <machine/param.h> 53 #include <machine/vmparam.h> 54 #include <machine/pmap.h> 55 56 #include <limits.h> 57 #include <db.h> 58 59 #include "kvm_private.h" 60 61 #include <machine/pte.h> 62 63 /* 64 * We access both normal and PAE entries in 32bit chunks. 65 * Use a local name to avoid conflicting with the kernel's maybe-public, 66 * maybe-not p[td]_entry_t typedefs. 67 */ 68 typedef u_long ptd_entry_t; 69 70 /* 71 * These must match the values in pmap.c/pmapae.c 72 * First the non-PAE versions 73 */ 74 #define PD_MASK 0xffc00000 /* page directory address bits */ 75 #define PT_MASK 0x003ff000 /* page table address bits */ 76 77 /* 78 * PAE versions 79 * 80 * paddr_t is still 32bits, so the top 32bits of PDEs and PTEs only 81 * matters for the NX bit...which libkvm doesn't care about 82 */ 83 #define PAE_PDSHIFT 21 84 #define PAE_PD_MASK 0xffe00000 /* page directory address bits */ 85 #define PAE_PT_MASK 0x001ff000 /* page table address bits */ 86 87 #define PG_FRAME 0xfffff000 88 89 static int cpu_pae; 90 91 struct vmstate { 92 ptd_entry_t *PTD; 93 ptd_entry_t PD_mask; 94 ptd_entry_t PT_mask; 95 int PD_shift; 96 int PG_shift; 97 }; 98 99 #define pdei(vm,VA) (((VA) & (vm)->PD_mask) >> (vm)->PD_shift) 100 #define ptei(vm,VA) (((VA) & (vm)->PT_mask) >> PAGE_SHIFT) 101 102 void 103 _kvm_freevtop(kvm_t *kd) 104 { 105 if (kd->vmst != NULL) { 106 free(kd->vmst->PTD); 107 108 free(kd->vmst); 109 kd->vmst = NULL; 110 } 111 } 112 113 int 114 _kvm_initvtop(kvm_t *kd) 115 { 116 struct nlist nl[4]; 117 struct vmstate *vm; 118 u_long pa, PTDsize; 119 120 vm = _kvm_malloc(kd, sizeof(*vm)); 121 if (vm == NULL) 122 return (-1); 123 kd->vmst = vm; 124 125 vm->PTD = NULL; 126 127 nl[0].n_name = "_PTDpaddr"; 128 nl[1].n_name = "_PTDsize"; 129 nl[2].n_name = "_cpu_pae"; 130 nl[3].n_name = NULL; 131 132 if (kvm_nlist(kd, nl) != 0) { 133 _kvm_err(kd, kd->program, "bad namelist"); 134 return (-1); 135 } 136 137 if (_kvm_pread(kd, kd->pmfd, &cpu_pae, sizeof cpu_pae, 138 _kvm_pa2off(kd, nl[2].n_value - KERNBASE)) != sizeof cpu_pae) 139 goto invalid; 140 141 if (_kvm_pread(kd, kd->pmfd, &PTDsize, sizeof PTDsize, 142 _kvm_pa2off(kd, nl[1].n_value - KERNBASE)) != sizeof PTDsize) 143 goto invalid; 144 145 if (_kvm_pread(kd, kd->pmfd, &pa, sizeof pa, 146 _kvm_pa2off(kd, nl[0].n_value - KERNBASE)) != sizeof pa) 147 goto invalid; 148 149 vm->PTD = _kvm_malloc(kd, PTDsize); 150 151 if (_kvm_pread(kd, kd->pmfd, vm->PTD, PTDsize, 152 _kvm_pa2off(kd, pa)) != PTDsize) 153 goto invalid; 154 155 if (cpu_pae) { 156 vm->PD_mask = PAE_PD_MASK; 157 vm->PT_mask = PAE_PT_MASK; 158 /* -1 here because entries are twice as large */ 159 vm->PD_shift = PAE_PDSHIFT - 1; 160 vm->PG_shift = PAGE_SHIFT - 1; 161 } else { 162 vm->PD_mask = PD_MASK; 163 vm->PT_mask = PT_MASK; 164 vm->PD_shift = PDSHIFT; 165 vm->PG_shift = PAGE_SHIFT; 166 } 167 168 return (0); 169 170 invalid: 171 free(vm->PTD); 172 vm->PTD = NULL; 173 return (-1); 174 } 175 176 /* 177 * Translate a kernel virtual address to a physical address. 178 */ 179 int 180 _kvm_kvatop(kvm_t *kd, u_long va, paddr_t *pa) 181 { 182 u_long offset, pte_pa; 183 struct vmstate *vm; 184 ptd_entry_t pte; 185 186 if (!kd->vmst) { 187 _kvm_err(kd, 0, "vatop called before initvtop"); 188 return (0); 189 } 190 191 if (ISALIVE(kd)) { 192 _kvm_err(kd, 0, "vatop called in live kernel!"); 193 return (0); 194 } 195 196 vm = kd->vmst; 197 offset = va & (kd->nbpg - 1); 198 199 /* 200 * If we are initializing (kernel page table descriptor pointer 201 * not yet set) * then return pa == va to avoid infinite recursion. 202 */ 203 if (vm->PTD == NULL) { 204 *pa = va; 205 return (kd->nbpg - (int)offset); 206 } 207 if ((vm->PTD[pdei(vm,va)] & PG_V) == 0) 208 goto invalid; 209 210 pte_pa = (vm->PTD[pdei(vm,va)] & PG_FRAME) + 211 (ptei(vm,va) * sizeof(ptd_entry_t)); 212 213 /* XXX READ PHYSICAL XXX */ 214 if (_kvm_pread(kd, kd->pmfd, &pte, sizeof pte, 215 _kvm_pa2off(kd, pte_pa)) != sizeof pte) 216 goto invalid; 217 218 if ((pte & PG_V) == 0) 219 goto invalid; 220 *pa = (pte & PG_FRAME) + offset; 221 return (kd->nbpg - (int)offset); 222 223 invalid: 224 _kvm_err(kd, 0, "invalid address (%lx)", va); 225 return (0); 226 } 227 228 /* 229 * Translate a physical address to a file-offset in the crash-dump. 230 */ 231 off_t 232 _kvm_pa2off(kvm_t *kd, paddr_t pa) 233 { 234 return ((off_t)(kd->dump_off + pa)); 235 } 236