lib/libkvm/kvm_minidump_amd64.c

   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("$FreeBSD$");
  28
  29 /*
  30  * AMD64 machine dependent routines for kvm and minidumps.
  31  */
  32
  33 #include <sys/param.h>
  34 #include <sys/endian.h>
  35 #include <stdint.h>
  36 #include <stdlib.h>
  37 #include <string.h>
  38 #include <unistd.h>
  39 #include <kvm.h>
  40
  41 #include "../../sys/amd64/include/minidump.h"
  42
  43 #include <limits.h>
  44
  45 #include "kvm_private.h"
  46 #include "kvm_amd64.h"
  47
  48 #define amd64_round_page(x)     roundup2((kvaddr_t)(x), AMD64_PAGE_SIZE)
  49
  50 struct vmstate {
  51         struct minidumphdr hdr;
  52         amd64_pte_t *page_map;
  53 };
  54
  55 static int
  56 _amd64_minidump_probe(kvm_t *kd)
  57 {
  58
  59         return (_kvm_probe_elf_kernel(kd, ELFCLASS64, EM_X86_64) &&
  60             _kvm_is_minidump(kd));
  61 }
  62
  63 static void
  64 _amd64_minidump_freevtop(kvm_t *kd)
  65 {
  66         struct vmstate *vm = kd->vmst;
  67
  68         free(vm->page_map);
  69         free(vm);
  70         kd->vmst = NULL;
  71 }
  72
  73 static int
  74 _amd64_minidump_initvtop(kvm_t *kd)
  75 {
  76         struct vmstate *vmst;
  77         off_t off, sparse_off;
  78
  79         vmst = _kvm_malloc(kd, sizeof(*vmst));
  80         if (vmst == NULL) {
  81                 _kvm_err(kd, kd->program, "cannot allocate vm");
  82                 return (-1);
  83         }
  84         kd->vmst = vmst;
  85         if (pread(kd->pmfd, &vmst->hdr, sizeof(vmst->hdr), 0) !=
  86             sizeof(vmst->hdr)) {
  87                 _kvm_err(kd, kd->program, "cannot read dump header");
  88                 return (-1);
  89         }
  90         if (strncmp(MINIDUMP_MAGIC, vmst->hdr.magic, sizeof(vmst->hdr.magic)) != 0) {
  91                 _kvm_err(kd, kd->program, "not a minidump for this platform");
  92                 return (-1);
  93         }
  94
  95         /*
  96          * NB: amd64 minidump header is binary compatible between version 1
  97          * and version 2; this may not be the case for the future versions.
  98          */
  99         vmst->hdr.version = le32toh(vmst->hdr.version);
 100         if (vmst->hdr.version != MINIDUMP_VERSION && vmst->hdr.version != 1) {
 101                 _kvm_err(kd, kd->program, "wrong minidump version. expected %d got %d",
 102                     MINIDUMP_VERSION, vmst->hdr.version);
 103                 return (-1);
 104         }
 105         vmst->hdr.msgbufsize = le32toh(vmst->hdr.msgbufsize);
 106         vmst->hdr.bitmapsize = le32toh(vmst->hdr.bitmapsize);
 107         vmst->hdr.pmapsize = le32toh(vmst->hdr.pmapsize);
 108         vmst->hdr.kernbase = le64toh(vmst->hdr.kernbase);
 109         vmst->hdr.dmapbase = le64toh(vmst->hdr.dmapbase);
 110         vmst->hdr.dmapend = le64toh(vmst->hdr.dmapend);
 111
 112         /* Skip header and msgbuf */
 113         off = AMD64_PAGE_SIZE + amd64_round_page(vmst->hdr.msgbufsize);
 114
 115         sparse_off = off + amd64_round_page(vmst->hdr.bitmapsize) +
 116             amd64_round_page(vmst->hdr.pmapsize);
 117         if (_kvm_pt_init(kd, vmst->hdr.bitmapsize, off, sparse_off,
 118             AMD64_PAGE_SIZE, sizeof(uint64_t)) == -1) {
 119                 _kvm_err(kd, kd->program, "cannot load core bitmap");
 120                 return (-1);
 121         }
 122         off += amd64_round_page(vmst->hdr.bitmapsize);
 123
 124         vmst->page_map = _kvm_malloc(kd, vmst->hdr.pmapsize);
 125         if (vmst->page_map == NULL) {
 126                 _kvm_err(kd, kd->program, "cannot allocate %d bytes for page_map",
 127                     vmst->hdr.pmapsize);
 128                 return (-1);
 129         }
 130         if (pread(kd->pmfd, vmst->page_map, vmst->hdr.pmapsize, off) !=
 131             (ssize_t)vmst->hdr.pmapsize) {
 132                 _kvm_err(kd, kd->program, "cannot read %d bytes for page_map",
 133                     vmst->hdr.pmapsize);
 134                 return (-1);
 135         }
 136         off += amd64_round_page(vmst->hdr.pmapsize);
 137
 138         return (0);
 139 }
 140
 141 static int
 142 _amd64_minidump_vatop_v1(kvm_t *kd, kvaddr_t va, off_t *pa)
 143 {
 144         struct vmstate *vm;
 145         amd64_physaddr_t offset;
 146         amd64_pte_t pte;
 147         kvaddr_t pteindex;
 148         amd64_physaddr_t a;
 149         off_t ofs;
 150
 151         vm = kd->vmst;
 152         offset = va & AMD64_PAGE_MASK;
 153
 154         if (va >= vm->hdr.kernbase) {
 155                 pteindex = (va - vm->hdr.kernbase) >> AMD64_PAGE_SHIFT;
 156                 if (pteindex >= vm->hdr.pmapsize / sizeof(*vm->page_map))
 157                         goto invalid;
 158                 pte = le64toh(vm->page_map[pteindex]);
 159                 if ((pte & AMD64_PG_V) == 0) {
 160                         _kvm_err(kd, kd->program,
 161                             "_amd64_minidump_vatop_v1: pte not valid");
 162                         goto invalid;
 163                 }
 164                 a = pte & AMD64_PG_FRAME;
 165                 ofs = _kvm_pt_find(kd, a);
 166                 if (ofs == -1) {
 167                         _kvm_err(kd, kd->program,
 168             "_amd64_minidump_vatop_v1: physical address 0x%jx not in minidump",
 169                             (uintmax_t)a);
 170                         goto invalid;
 171                 }
 172                 *pa = ofs + offset;
 173                 return (AMD64_PAGE_SIZE - offset);
 174         } else if (va >= vm->hdr.dmapbase && va < vm->hdr.dmapend) {
 175                 a = (va - vm->hdr.dmapbase) & ~AMD64_PAGE_MASK;
 176                 ofs = _kvm_pt_find(kd, a);
 177                 if (ofs == -1) {
 178                         _kvm_err(kd, kd->program,
 179     "_amd64_minidump_vatop_v1: direct map address 0x%jx not in minidump",
 180                             (uintmax_t)va);
 181                         goto invalid;
 182                 }
 183                 *pa = ofs + offset;
 184                 return (AMD64_PAGE_SIZE - offset);
 185         } else {
 186                 _kvm_err(kd, kd->program,
 187             "_amd64_minidump_vatop_v1: virtual address 0x%jx not minidumped",
 188                     (uintmax_t)va);
 189                 goto invalid;
 190         }
 191
 192 invalid:
 193         _kvm_err(kd, 0, "invalid address (0x%jx)", (uintmax_t)va);
 194         return (0);
 195 }
 196
 197 static int
 198 _amd64_minidump_vatop(kvm_t *kd, kvaddr_t va, off_t *pa)
 199 {
 200         amd64_pte_t pt[AMD64_NPTEPG];
 201         struct vmstate *vm;
 202         amd64_physaddr_t offset;
 203         amd64_pde_t pde;
 204         amd64_pte_t pte;
 205         kvaddr_t pteindex;
 206         kvaddr_t pdeindex;
 207         amd64_physaddr_t a;
 208         off_t ofs;
 209
 210         vm = kd->vmst;
 211         offset = va & AMD64_PAGE_MASK;
 212
 213         if (va >= vm->hdr.kernbase) {
 214                 pdeindex = (va - vm->hdr.kernbase) >> AMD64_PDRSHIFT;
 215                 if (pdeindex >= vm->hdr.pmapsize / sizeof(*vm->page_map))
 216                         goto invalid;
 217                 pde = le64toh(vm->page_map[pdeindex]);
 218                 if ((pde & AMD64_PG_V) == 0) {
 219                         _kvm_err(kd, kd->program,
 220                             "_amd64_minidump_vatop: pde not valid");
 221                         goto invalid;
 222                 }
 223                 if ((pde & AMD64_PG_PS) == 0) {
 224                         a = pde & AMD64_PG_FRAME;
 225                         /* TODO: Just read the single PTE */
 226                         ofs = _kvm_pt_find(kd, a);
 227                         if (ofs == -1) {
 228                                 _kvm_err(kd, kd->program,
 229                                     "cannot find page table entry for %ju",
 230                                     (uintmax_t)a);
 231                                 goto invalid;
 232                         }
 233                         if (pread(kd->pmfd, &pt, AMD64_PAGE_SIZE, ofs) !=
 234                             AMD64_PAGE_SIZE) {
 235                                 _kvm_err(kd, kd->program,
 236                                     "cannot read page table entry for %ju",
 237                                     (uintmax_t)a);
 238                                 goto invalid;
 239                         }
 240                         pteindex = (va >> AMD64_PAGE_SHIFT) &
 241                             (AMD64_NPTEPG - 1);
 242                         pte = le64toh(pt[pteindex]);
 243                         if ((pte & AMD64_PG_V) == 0) {
 244                                 _kvm_err(kd, kd->program,
 245                                     "_amd64_minidump_vatop: pte not valid");
 246                                 goto invalid;
 247                         }
 248                         a = pte & AMD64_PG_FRAME;
 249                 } else {
 250                         a = pde & AMD64_PG_PS_FRAME;
 251                         a += (va & AMD64_PDRMASK) ^ offset;
 252                 }
 253                 ofs = _kvm_pt_find(kd, a);
 254                 if (ofs == -1) {
 255                         _kvm_err(kd, kd->program,
 256             "_amd64_minidump_vatop: physical address 0x%jx not in minidump",
 257                             (uintmax_t)a);
 258                         goto invalid;
 259                 }
 260                 *pa = ofs + offset;
 261                 return (AMD64_PAGE_SIZE - offset);
 262         } else if (va >= vm->hdr.dmapbase && va < vm->hdr.dmapend) {
 263                 a = (va - vm->hdr.dmapbase) & ~AMD64_PAGE_MASK;
 264                 ofs = _kvm_pt_find(kd, a);
 265                 if (ofs == -1) {
 266                         _kvm_err(kd, kd->program,
 267             "_amd64_minidump_vatop: direct map address 0x%jx not in minidump",
 268                             (uintmax_t)va);
 269                         goto invalid;
 270                 }
 271                 *pa = ofs + offset;
 272                 return (AMD64_PAGE_SIZE - offset);
 273         } else {
 274                 _kvm_err(kd, kd->program,
 275             "_amd64_minidump_vatop: virtual address 0x%jx not minidumped",
 276                     (uintmax_t)va);
 277                 goto invalid;
 278         }
 279
 280 invalid:
 281         _kvm_err(kd, 0, "invalid address (0x%jx)", (uintmax_t)va);
 282         return (0);
 283 }
 284
 285 static int
 286 _amd64_minidump_kvatop(kvm_t *kd, kvaddr_t va, off_t *pa)
 287 {
 288
 289         if (ISALIVE(kd)) {
 290                 _kvm_err(kd, 0,
 291                     "_amd64_minidump_kvatop called in live kernel!");
 292                 return (0);
 293         }
 294         if (((struct vmstate *)kd->vmst)->hdr.version == 1)
 295                 return (_amd64_minidump_vatop_v1(kd, va, pa));
 296         else
 297                 return (_amd64_minidump_vatop(kd, va, pa));
 298 }
 299
 300 static struct kvm_arch kvm_amd64_minidump = {
 301         .ka_probe = _amd64_minidump_probe,
 302         .ka_initvtop = _amd64_minidump_initvtop,
 303         .ka_freevtop = _amd64_minidump_freevtop,
 304         .ka_kvatop = _amd64_minidump_kvatop,
 305         .ka_native = _amd64_native,
 306 };
 307
 308 KVM_ARCH(kvm_amd64_minidump);