1 /* $OpenBSD: kvm_amd64.c,v 1.14 2021/09/10 00:02:43 deraadt Exp $ */ 2 /* $NetBSD: kvm_x86_64.c,v 1.3 2002/06/05 22:01:55 fvdl 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 * x86-64 machine dependent routines for kvm. 39 */ 40 41 #include <sys/param.h> /* MAXCOMLEN ALIGN */ 42 #include <sys/types.h> 43 #include <sys/signal.h> 44 #include <sys/proc.h> 45 #include <sys/stat.h> 46 #include <sys/kcore.h> 47 #include <machine/kcore.h> 48 #include <stdlib.h> 49 #include <unistd.h> 50 #include <nlist.h> 51 #include <kvm.h> 52 53 #include <uvm/uvm_extern.h> 54 55 #include <limits.h> 56 #include <db.h> 57 58 #include "kvm_private.h" 59 60 #include <machine/pmap.h> 61 #include <machine/pte.h> 62 #include <machine/vmparam.h> 63 64 void 65 _kvm_freevtop(kvm_t *kd) 66 { 67 /* Not actually used for anything right now, but safe. */ 68 free(kd->vmst); 69 kd->vmst = NULL; 70 } 71 72 /*ARGSUSED*/ 73 int 74 _kvm_initvtop(kvm_t *kd) 75 { 76 77 return (0); 78 } 79 80 /* 81 * Translate a kernel virtual address to a physical address. 82 */ 83 int 84 _kvm_kvatop(kvm_t *kd, u_long va, paddr_t *pa) 85 { 86 cpu_kcore_hdr_t *cpu_kh; 87 paddr_t pde_pa, pte_pa; 88 u_long page_off; 89 pd_entry_t pde; 90 pt_entry_t pte; 91 92 if (ISALIVE(kd)) { 93 _kvm_err(kd, 0, "vatop called in live kernel!"); 94 return (0); 95 } 96 97 page_off = va & (kd->nbpg - 1); 98 99 if (va >= PMAP_DIRECT_BASE && va <= PMAP_DIRECT_END) { 100 *pa = va - PMAP_DIRECT_BASE; 101 return (int)(kd->nbpg - page_off); 102 } 103 104 cpu_kh = kd->cpu_data; 105 106 /* 107 * Find and read all entries to get to the pa. 108 */ 109 110 /* 111 * Level 4. 112 */ 113 pde_pa = cpu_kh->ptdpaddr + (pl4_pi(va) * sizeof(pd_entry_t)); 114 if (pread(kd->pmfd, (void *)&pde, sizeof(pde), 115 _kvm_pa2off(kd, pde_pa)) != sizeof(pde)) { 116 _kvm_syserr(kd, 0, "could not read PT level 4 entry"); 117 goto lose; 118 } 119 if ((pde & PG_V) == 0) { 120 _kvm_err(kd, 0, "invalid translation (invalid level 4 PDE)"); 121 goto lose; 122 } 123 124 /* 125 * Level 3. 126 */ 127 pde_pa = (pde & PG_FRAME) + (pl3_pi(va) * sizeof(pd_entry_t)); 128 if (pread(kd->pmfd, (void *)&pde, sizeof(pde), 129 _kvm_pa2off(kd, pde_pa)) != sizeof(pde)) { 130 _kvm_syserr(kd, 0, "could not read PT level 3 entry"); 131 goto lose; 132 } 133 if ((pde & PG_V) == 0) { 134 _kvm_err(kd, 0, "invalid translation (invalid level 3 PDE)"); 135 goto lose; 136 } 137 138 /* 139 * Level 2. 140 */ 141 pde_pa = (pde & PG_FRAME) + (pl2_pi(va) * sizeof(pd_entry_t)); 142 if (pread(kd->pmfd, (void *)&pde, sizeof(pde), 143 _kvm_pa2off(kd, pde_pa)) != sizeof(pde)) { 144 _kvm_syserr(kd, 0, "could not read PT level 2 entry"); 145 goto lose; 146 } 147 if ((pde & PG_V) == 0) { 148 _kvm_err(kd, 0, "invalid translation (invalid level 2 PDE)"); 149 goto lose; 150 } 151 152 /* 153 * Might be a large page. 154 */ 155 if ((pde & PG_PS) != 0) { 156 page_off = va & (NBPD_L2 - 1); 157 *pa = (pde & PG_LGFRAME) | page_off; 158 return (int)(NBPD_L2 - page_off); 159 } 160 161 /* 162 * Level 1. 163 */ 164 pte_pa = (pde & PG_FRAME) + (pl1_pi(va) * sizeof(pt_entry_t)); 165 if (pread(kd->pmfd, (void *) &pte, sizeof(pte), 166 _kvm_pa2off(kd, pte_pa)) != sizeof(pte)) { 167 _kvm_syserr(kd, 0, "could not read PTE"); 168 goto lose; 169 } 170 /* 171 * Validate the PTE and return the physical address. 172 */ 173 if ((pte & PG_V) == 0) { 174 _kvm_err(kd, 0, "invalid translation (invalid PTE)"); 175 goto lose; 176 } 177 *pa = (pte & PG_FRAME) + page_off; 178 return (int)(kd->nbpg - page_off); 179 180 lose: 181 *pa = (u_long)~0L; 182 return (0); 183 } 184 185 /* 186 * Translate a physical address to a file-offset in the crash dump. 187 */ 188 off_t 189 _kvm_pa2off(kvm_t *kd, paddr_t pa) 190 { 191 cpu_kcore_hdr_t *cpu_kh; 192 phys_ram_seg_t *ramsegs; 193 off_t off; 194 int i; 195 196 cpu_kh = kd->cpu_data; 197 ramsegs = (void *)((char *)(void *)cpu_kh + ALIGN(sizeof *cpu_kh)); 198 199 off = 0; 200 for (i = 0; i < cpu_kh->nmemsegs; i++) { 201 if (pa >= ramsegs[i].start && 202 (pa - ramsegs[i].start) < ramsegs[i].size) { 203 off += (pa - ramsegs[i].start); 204 break; 205 } 206 off += ramsegs[i].size; 207 } 208 209 if (i == cpu_kh->nmemsegs) 210 _kvm_err(kd, 0, "pa %lx not in dump", pa); 211 212 return (kd->dump_off + off); 213 } 214