lib/libkvm/kvm_minidump_i386.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
  28 /*
  29  * AMD64 machine dependent routines for kvm and minidumps.
  30  */
  31
  32 #include <sys/param.h>
  33 #include <sys/user.h>
  34 #include <sys/proc.h>
  35 #include <sys/stat.h>
  36 #include <sys/mman.h>
  37 #include <sys/fnv_hash.h>
  38 #include <stdlib.h>
  39 #include <string.h>
  40 #include <strings.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
  58 struct 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! */
  67 struct 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
  75 static void
  76 hpt_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
  90 static int64_t
  91 hpt_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
 105 static int
 106 inithash(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
 125 void
 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
 138 int
 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         bzero(vmst, sizeof(*vmst));
 151         vmst->minidump = 1;
 152         if (pread(kd->pmfd, &vmst->hdr, sizeof(vmst->hdr), 0) !=
 153             sizeof(vmst->hdr)) {
 154                 _kvm_err(kd, kd->program, "cannot read dump header");
 155                 return (-1);
 156         }
 157         if (strncmp(MINIDUMP_MAGIC, vmst->hdr.magic, sizeof(vmst->hdr.magic)) != 0) {
 158                 _kvm_err(kd, kd->program, "not a minidump for this platform");
 159                 return (-1);
 160         }
 161         if (vmst->hdr.version != MINIDUMP_VERSION) {
 162                 _kvm_err(kd, kd->program, "wrong minidump version. expected %d got %d",
 163                     MINIDUMP_VERSION, vmst->hdr.version);
 164                 return (-1);
 165         }
 166
 167         /* Skip header and msgbuf */
 168         off = PAGE_SIZE + round_page(vmst->hdr.msgbufsize);
 169
 170         vmst->bitmap = _kvm_malloc(kd, vmst->hdr.bitmapsize);
 171         if (vmst->bitmap == NULL) {
 172                 _kvm_err(kd, kd->program, "cannot allocate %d bytes for bitmap", vmst->hdr.bitmapsize);
 173                 return (-1);
 174         }
 175         if (pread(kd->pmfd, vmst->bitmap, vmst->hdr.bitmapsize, off) !=
 176             vmst->hdr.bitmapsize) {
 177                 _kvm_err(kd, kd->program, "cannot read %d bytes for page bitmap", vmst->hdr.bitmapsize);
 178                 return (-1);
 179         }
 180         off += round_page(vmst->hdr.bitmapsize);
 181
 182         vmst->ptemap = _kvm_malloc(kd, vmst->hdr.ptesize);
 183         if (vmst->ptemap == NULL) {
 184                 _kvm_err(kd, kd->program, "cannot allocate %d bytes for ptemap", vmst->hdr.ptesize);
 185                 return (-1);
 186         }
 187         if (pread(kd->pmfd, vmst->ptemap, vmst->hdr.ptesize, off) !=
 188             vmst->hdr.ptesize) {
 189                 _kvm_err(kd, kd->program, "cannot read %d bytes for ptemap", vmst->hdr.ptesize);
 190                 return (-1);
 191         }
 192         off += vmst->hdr.ptesize;
 193
 194         /* build physical address hash table for sparse pages */
 195         inithash(kd, vmst->bitmap, vmst->hdr.bitmapsize, off);
 196
 197         return (0);
 198 }
 199
 200 static int
 201 _kvm_minidump_vatop(kvm_t *kd, u_long va, off_t *pa)
 202 {
 203         struct vmstate *vm;
 204         u_long offset;
 205         pt_entry_t pte;
 206         u_long pteindex;
 207         u_long a;
 208         off_t ofs;
 209         uint32_t *ptemap;
 210
 211         vm = kd->vmst;
 212         ptemap = vm->ptemap;
 213         offset = va & (PAGE_SIZE - 1);
 214
 215         if (va >= vm->hdr.kernbase) {
 216                 pteindex = (va - vm->hdr.kernbase) >> PAGE_SHIFT;
 217                 pte = ptemap[pteindex];
 218                 if ((pte & PG_V) == 0) {
 219                         _kvm_err(kd, kd->program, "_kvm_vatop: pte not valid");
 220                         goto invalid;
 221                 }
 222                 a = pte & PG_FRAME;
 223                 ofs = hpt_find(kd, a);
 224                 if (ofs == -1) {
 225                         _kvm_err(kd, kd->program, "_kvm_vatop: physical address 0x%lx not in minidump", a);
 226                         goto invalid;
 227                 }
 228                 *pa = ofs + offset;
 229                 return (PAGE_SIZE - offset);
 230         } else {
 231                 _kvm_err(kd, kd->program, "_kvm_vatop: virtual address 0x%lx not minidumped", va);
 232                 goto invalid;
 233         }
 234
 235 invalid:
 236         _kvm_err(kd, 0, "invalid address (0x%lx)", va);
 237         return (0);
 238 }
 239
 240 int
 241 _kvm_minidump_kvatop(kvm_t *kd, u_long va, off_t *pa)
 242 {
 243
 244         if (kvm_ishost(kd)) {
 245                 _kvm_err(kd, 0, "vatop called in live kernel!");
 246                 return (0);
 247         }
 248
 249         return (_kvm_minidump_vatop(kd, va, pa));
 250 }