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 /*
  27  * AMD64 machine dependent routines for kvm and minidumps.
  28  */
  29 #include <sys/user.h>
  30 #include <sys/param.h>
  31 #include <sys/proc.h>
  32 #include <sys/stat.h>
  33 #include <sys/mman.h>
  34 #include <sys/fnv_hash.h>
  35 #include <stdlib.h>
  36 #include <string.h>
  37 #include <strings.h>
  38 #include <unistd.h>
  39 #include <nlist.h>
  40 #include <kvm.h>
  41
  42 #include <vm/vm.h>
  43 #include <vm/vm_param.h>
  44
  45 #include <machine/elf.h>
  46 #include <machine/cpufunc.h>
  47 #include <machine/minidump.h>
  48
  49 #include <limits.h>
  50
  51 #include "kvm_private.h"
  52
  53 #define PG_FRAME_PAE    (~((uint64_t)PAGE_MASK))
  54
  55 struct hpte {
  56         struct hpte *next;
  57         uint64_t pa;
  58         int64_t off;
  59 };
  60
  61 #define HPT_SIZE 1024
  62
  63 /* minidump must be the first item! */
  64 struct vmstate {
  65         int minidump;           /* 1 = minidump mode */
  66         struct minidumphdr hdr;
  67         void *hpt_head[HPT_SIZE];
  68         uint32_t *bitmap;
  69         void *ptemap;
  70 };
  71
  72 static void
  73 hpt_insert(kvm_t *kd, uint64_t pa, int64_t off)
  74 {
  75         struct hpte *hpte;
  76         uint32_t fnv = FNV1_32_INIT;
  77
  78         fnv = fnv_32_buf(&pa, sizeof(pa), fnv);
  79         fnv &= (HPT_SIZE - 1);
  80         hpte = malloc(sizeof(*hpte));
  81         hpte->pa = pa;
  82         hpte->off = off;
  83         hpte->next = kd->vmst->hpt_head[fnv];
  84         kd->vmst->hpt_head[fnv] = hpte;
  85 }
  86
  87 static int64_t
  88 hpt_find(kvm_t *kd, uint64_t pa)
  89 {
  90         struct hpte *hpte;
  91         uint32_t fnv = FNV1_32_INIT;
  92
  93         fnv = fnv_32_buf(&pa, sizeof(pa), fnv);
  94         fnv &= (HPT_SIZE - 1);
  95         for (hpte = kd->vmst->hpt_head[fnv]; hpte != NULL; hpte = hpte->next) {
  96                 if (pa == hpte->pa)
  97                         return (hpte->off);
  98         }
  99         return (-1);
 100 }
 101
 102 static int
 103 inithash(kvm_t *kd, uint32_t *base, int len, off_t off)
 104 {
 105         uint64_t idx;
 106         uint32_t bit, bits;
 107         uint64_t pa;
 108
 109         for (idx = 0; idx < len / sizeof(*base); idx++) {
 110                 bits = base[idx];
 111                 while (bits) {
 112                         bit = bsfl(bits);
 113                         bits &= ~(1ul << bit);
 114                         pa = (idx * sizeof(*base) * NBBY + bit) * PAGE_SIZE;
 115                         hpt_insert(kd, pa, off);
 116                         off += PAGE_SIZE;
 117                 }
 118         }
 119         return (off);
 120 }
 121
 122 void
 123 _kvm_minidump_freevtop(kvm_t *kd)
 124 {
 125         struct vmstate *vm = kd->vmst;
 126
 127         if (vm->bitmap)
 128                 free(vm->bitmap);
 129         if (vm->ptemap)
 130                 free(vm->ptemap);
 131         free(vm);
 132         kd->vmst = NULL;
 133 }
 134
 135 int
 136 _kvm_minidump_initvtop(kvm_t *kd)
 137 {
 138         struct vmstate *vmst;
 139         off_t off;
 140
 141         vmst = _kvm_malloc(kd, sizeof(*vmst));
 142         if (vmst == NULL) {
 143                 _kvm_err(kd, kd->program, "cannot allocate vm");
 144                 return (-1);
 145         }
 146         kd->vmst = vmst;
 147         bzero(vmst, sizeof(*vmst));
 148         vmst->minidump = 1;
 149         if (pread(kd->pmfd, &vmst->hdr, sizeof(vmst->hdr), 0) !=
 150             sizeof(vmst->hdr)) {
 151                 _kvm_err(kd, kd->program, "cannot read dump header");
 152                 return (-1);
 153         }
 154         if (strncmp(MINIDUMP_MAGIC, vmst->hdr.magic, sizeof(vmst->hdr.magic)) != 0) {
 155                 _kvm_err(kd, kd->program, "not a minidump for this platform");
 156                 return (-1);
 157         }
 158         if (vmst->hdr.version != MINIDUMP_VERSION) {
 159                 _kvm_err(kd, kd->program, "wrong minidump version. expected %d got %d",
 160                     MINIDUMP_VERSION, vmst->hdr.version);
 161                 return (-1);
 162         }
 163
 164         /* Skip header and msgbuf */
 165         off = PAGE_SIZE + round_page(vmst->hdr.msgbufsize);
 166
 167         vmst->bitmap = _kvm_malloc(kd, vmst->hdr.bitmapsize);
 168         if (vmst->bitmap == NULL) {
 169                 _kvm_err(kd, kd->program, "cannot allocate %d bytes for bitmap", vmst->hdr.bitmapsize);
 170                 return (-1);
 171         }
 172         if (pread(kd->pmfd, vmst->bitmap, vmst->hdr.bitmapsize, off) !=
 173             vmst->hdr.bitmapsize) {
 174                 _kvm_err(kd, kd->program, "cannot read %d bytes for page bitmap", vmst->hdr.bitmapsize);
 175                 return (-1);
 176         }
 177         off += round_page(vmst->hdr.bitmapsize);
 178
 179         vmst->ptemap = _kvm_malloc(kd, vmst->hdr.ptesize);
 180         if (vmst->ptemap == NULL) {
 181                 _kvm_err(kd, kd->program, "cannot allocate %d bytes for ptemap", vmst->hdr.ptesize);
 182                 return (-1);
 183         }
 184         if (pread(kd->pmfd, vmst->ptemap, vmst->hdr.ptesize, off) !=
 185             vmst->hdr.ptesize) {
 186                 _kvm_err(kd, kd->program, "cannot read %d bytes for ptemap", vmst->hdr.ptesize);
 187                 return (-1);
 188         }
 189         off += vmst->hdr.ptesize;
 190
 191         /* build physical address hash table for sparse pages */
 192         inithash(kd, vmst->bitmap, vmst->hdr.bitmapsize, off);
 193
 194         return (0);
 195 }
 196
 197 static int
 198 _kvm_minidump_vatop(kvm_t *kd, u_long va, off_t *pa)
 199 {
 200         struct vmstate *vm;
 201         u_long offset;
 202         pt_entry_t pte;
 203         u_long pteindex;
 204         u_long a;
 205         off_t ofs;
 206         uint32_t *ptemap;
 207
 208         vm = kd->vmst;
 209         ptemap = vm->ptemap;
 210         offset = va & (PAGE_SIZE - 1);
 211
 212         if (va >= vm->hdr.kernbase) {
 213                 pteindex = (va - vm->hdr.kernbase) >> PAGE_SHIFT;
 214                 pte = ptemap[pteindex];
 215                 if ((pte & PG_V) == 0) {
 216                         _kvm_err(kd, kd->program, "_kvm_vatop: pte not valid");
 217                         goto invalid;
 218                 }
 219                 a = pte & PG_FRAME;
 220                 ofs = hpt_find(kd, a);
 221                 if (ofs == -1) {
 222                         _kvm_err(kd, kd->program, "_kvm_vatop: physical address 0x%lx not in minidump", a);
 223                         goto invalid;
 224                 }
 225                 *pa = ofs + offset;
 226                 return (PAGE_SIZE - offset);
 227         } else {
 228                 _kvm_err(kd, kd->program, "_kvm_vatop: virtual address 0x%lx not minidumped", va);
 229                 goto invalid;
 230         }
 231
 232 invalid:
 233         _kvm_err(kd, 0, "invalid address (0x%lx)", va);
 234         return (0);
 235 }
 236
 237 int
 238 _kvm_minidump_kvatop(kvm_t *kd, u_long va, off_t *pa)
 239 {
 240
 241         if (kvm_ishost(kd)) {
 242                 _kvm_err(kd, 0, "vatop called in live kernel!");
 243                 return (0);
 244         }
 245
 246         return (_kvm_minidump_vatop(kd, va, pa));
 247 }