kvm_minidump_i386.c revision 217744
1/*- 2 * Copyright (c) 2006 Peter Wemm 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23 * SUCH DAMAGE. 24 */ 25 26#include <sys/cdefs.h> 27__FBSDID("$FreeBSD: head/lib/libkvm/kvm_minidump_i386.c 217744 2011-01-23 11:08:28Z uqs $"); 28 29/* 30 * AMD64 machine dependent routines for kvm and minidumps. 31 */ 32 33#include <sys/param.h> 34#include <sys/user.h> 35#include <sys/proc.h> 36#include <sys/stat.h> 37#include <sys/mman.h> 38#include <sys/fnv_hash.h> 39#include <stdlib.h> 40#include <string.h> 41#include <unistd.h> 42#include <nlist.h> 43#include <kvm.h> 44 45#include <vm/vm.h> 46#include <vm/vm_param.h> 47 48#include <machine/elf.h> 49#include <machine/cpufunc.h> 50#include <machine/minidump.h> 51 52#include <limits.h> 53 54#include "kvm_private.h" 55 56#define PG_FRAME_PAE (~((uint64_t)PAGE_MASK)) 57 58struct hpte { 59 struct hpte *next; 60 uint64_t pa; 61 int64_t off; 62}; 63 64#define HPT_SIZE 1024 65 66/* minidump must be the first item! */ 67struct vmstate { 68 int minidump; /* 1 = minidump mode */ 69 struct minidumphdr hdr; 70 void *hpt_head[HPT_SIZE]; 71 uint32_t *bitmap; 72 void *ptemap; 73}; 74 75static void 76hpt_insert(kvm_t *kd, uint64_t pa, int64_t off) 77{ 78 struct hpte *hpte; 79 uint32_t fnv = FNV1_32_INIT; 80 81 fnv = fnv_32_buf(&pa, sizeof(pa), fnv); 82 fnv &= (HPT_SIZE - 1); 83 hpte = malloc(sizeof(*hpte)); 84 hpte->pa = pa; 85 hpte->off = off; 86 hpte->next = kd->vmst->hpt_head[fnv]; 87 kd->vmst->hpt_head[fnv] = hpte; 88} 89 90static int64_t 91hpt_find(kvm_t *kd, uint64_t pa) 92{ 93 struct hpte *hpte; 94 uint32_t fnv = FNV1_32_INIT; 95 96 fnv = fnv_32_buf(&pa, sizeof(pa), fnv); 97 fnv &= (HPT_SIZE - 1); 98 for (hpte = kd->vmst->hpt_head[fnv]; hpte != NULL; hpte = hpte->next) { 99 if (pa == hpte->pa) 100 return (hpte->off); 101 } 102 return (-1); 103} 104 105static int 106inithash(kvm_t *kd, uint32_t *base, int len, off_t off) 107{ 108 uint64_t idx; 109 uint32_t bit, bits; 110 uint64_t pa; 111 112 for (idx = 0; idx < len / sizeof(*base); idx++) { 113 bits = base[idx]; 114 while (bits) { 115 bit = bsfl(bits); 116 bits &= ~(1ul << bit); 117 pa = (idx * sizeof(*base) * NBBY + bit) * PAGE_SIZE; 118 hpt_insert(kd, pa, off); 119 off += PAGE_SIZE; 120 } 121 } 122 return (off); 123} 124 125void 126_kvm_minidump_freevtop(kvm_t *kd) 127{ 128 struct vmstate *vm = kd->vmst; 129 130 if (vm->bitmap) 131 free(vm->bitmap); 132 if (vm->ptemap) 133 free(vm->ptemap); 134 free(vm); 135 kd->vmst = NULL; 136} 137 138int 139_kvm_minidump_initvtop(kvm_t *kd) 140{ 141 struct vmstate *vmst; 142 off_t off; 143 144 vmst = _kvm_malloc(kd, sizeof(*vmst)); 145 if (vmst == 0) { 146 _kvm_err(kd, kd->program, "cannot allocate vm"); 147 return (-1); 148 } 149 kd->vmst = vmst; 150 vmst->minidump = 1; 151 if (pread(kd->pmfd, &vmst->hdr, sizeof(vmst->hdr), 0) != 152 sizeof(vmst->hdr)) { 153 _kvm_err(kd, kd->program, "cannot read dump header"); 154 return (-1); 155 } 156 if (strncmp(MINIDUMP_MAGIC, vmst->hdr.magic, sizeof(vmst->hdr.magic)) != 0) { 157 _kvm_err(kd, kd->program, "not a minidump for this platform"); 158 return (-1); 159 } 160 if (vmst->hdr.version != MINIDUMP_VERSION) { 161 _kvm_err(kd, kd->program, "wrong minidump version. expected %d got %d", 162 MINIDUMP_VERSION, vmst->hdr.version); 163 return (-1); 164 } 165 166 /* Skip header and msgbuf */ 167 off = PAGE_SIZE + round_page(vmst->hdr.msgbufsize); 168 169 vmst->bitmap = _kvm_malloc(kd, vmst->hdr.bitmapsize); 170 if (vmst->bitmap == NULL) { 171 _kvm_err(kd, kd->program, "cannot allocate %d bytes for bitmap", vmst->hdr.bitmapsize); 172 return (-1); 173 } 174 if (pread(kd->pmfd, vmst->bitmap, vmst->hdr.bitmapsize, off) != 175 (ssize_t)vmst->hdr.bitmapsize) { 176 _kvm_err(kd, kd->program, "cannot read %d bytes for page bitmap", vmst->hdr.bitmapsize); 177 return (-1); 178 } 179 off += round_page(vmst->hdr.bitmapsize); 180 181 vmst->ptemap = _kvm_malloc(kd, vmst->hdr.ptesize); 182 if (vmst->ptemap == NULL) { 183 _kvm_err(kd, kd->program, "cannot allocate %d bytes for ptemap", vmst->hdr.ptesize); 184 return (-1); 185 } 186 if (pread(kd->pmfd, vmst->ptemap, vmst->hdr.ptesize, off) != 187 (ssize_t)vmst->hdr.ptesize) { 188 _kvm_err(kd, kd->program, "cannot read %d bytes for ptemap", vmst->hdr.ptesize); 189 return (-1); 190 } 191 off += vmst->hdr.ptesize; 192 193 /* build physical address hash table for sparse pages */ 194 inithash(kd, vmst->bitmap, vmst->hdr.bitmapsize, off); 195 196 return (0); 197} 198 199static int 200_kvm_minidump_vatop_pae(kvm_t *kd, u_long va, off_t *pa) 201{ 202 struct vmstate *vm; 203 uint64_t offset; 204 uint64_t pte; 205 u_long pteindex; 206 uint64_t a; 207 off_t ofs; 208 uint64_t *ptemap; 209 210 vm = kd->vmst; 211 ptemap = vm->ptemap; 212 offset = va & (PAGE_SIZE - 1); 213 214 if (va >= vm->hdr.kernbase) { 215 pteindex = (va - vm->hdr.kernbase) >> PAGE_SHIFT; 216 pte = ptemap[pteindex]; 217 if ((pte & PG_V) == 0) { 218 _kvm_err(kd, kd->program, "_kvm_vatop: pte not valid"); 219 goto invalid; 220 } 221 a = pte & PG_FRAME_PAE; 222 ofs = hpt_find(kd, a); 223 if (ofs == -1) { 224 _kvm_err(kd, kd->program, "_kvm_vatop: physical address 0x%llx not in minidump", a); 225 goto invalid; 226 } 227 *pa = ofs + offset; 228 return (PAGE_SIZE - offset); 229 } else { 230 _kvm_err(kd, kd->program, "_kvm_vatop: virtual address 0x%lx not minidumped", va); 231 goto invalid; 232 } 233 234invalid: 235 _kvm_err(kd, 0, "invalid address (0x%lx)", va); 236 return (0); 237} 238 239static int 240_kvm_minidump_vatop(kvm_t *kd, u_long va, off_t *pa) 241{ 242 struct vmstate *vm; 243 u_long offset; 244 pt_entry_t pte; 245 u_long pteindex; 246 u_long a; 247 off_t ofs; 248 uint32_t *ptemap; 249 250 vm = kd->vmst; 251 ptemap = vm->ptemap; 252 offset = va & (PAGE_SIZE - 1); 253 254 if (va >= vm->hdr.kernbase) { 255 pteindex = (va - vm->hdr.kernbase) >> PAGE_SHIFT; 256 pte = ptemap[pteindex]; 257 if ((pte & PG_V) == 0) { 258 _kvm_err(kd, kd->program, "_kvm_vatop: pte not valid"); 259 goto invalid; 260 } 261 a = pte & PG_FRAME; 262 ofs = hpt_find(kd, a); 263 if (ofs == -1) { 264 _kvm_err(kd, kd->program, "_kvm_vatop: physical address 0x%lx not in minidump", a); 265 goto invalid; 266 } 267 *pa = ofs + offset; 268 return (PAGE_SIZE - offset); 269 } else { 270 _kvm_err(kd, kd->program, "_kvm_vatop: virtual address 0x%lx not minidumped", va); 271 goto invalid; 272 } 273 274invalid: 275 _kvm_err(kd, 0, "invalid address (0x%lx)", va); 276 return (0); 277} 278 279int 280_kvm_minidump_kvatop(kvm_t *kd, u_long va, off_t *pa) 281{ 282 283 if (ISALIVE(kd)) { 284 _kvm_err(kd, 0, "kvm_kvatop called in live kernel!"); 285 return (0); 286 } 287 if (kd->vmst->hdr.paemode) 288 return (_kvm_minidump_vatop_pae(kd, va, pa)); 289 else 290 return (_kvm_minidump_vatop(kd, va, pa)); 291} 292