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/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 <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 struct hpte {
  57         struct hpte *next;
  58         vm_paddr_t pa;
  59         int64_t off;
  60 };
  61
  62 #define HPT_SIZE 1024
  63
  64 /* minidump must be the first item! */
  65 struct vmstate {
  66         int minidump;           /* 1 = minidump mode */
  67         struct minidumphdr hdr;
  68         void *hpt_head[HPT_SIZE];
  69         uint64_t *bitmap;
  70         uint64_t *ptemap;
  71 };
  72
  73 static void
  74 hpt_insert(kvm_t *kd, vm_paddr_t pa, int64_t off)
  75 {
  76         struct hpte *hpte;
  77         uint32_t fnv = FNV1_32_INIT;
  78
  79         fnv = fnv_32_buf(&pa, sizeof(pa), fnv);
  80         fnv &= (HPT_SIZE - 1);
  81         hpte = malloc(sizeof(*hpte));
  82         hpte->pa = pa;
  83         hpte->off = off;
  84         hpte->next = kd->vmst->hpt_head[fnv];
  85         kd->vmst->hpt_head[fnv] = hpte;
  86 }
  87
  88 static int64_t
  89 hpt_find(kvm_t *kd, vm_paddr_t pa)
  90 {
  91         struct hpte *hpte;
  92         uint32_t fnv = FNV1_32_INIT;
  93
  94         fnv = fnv_32_buf(&pa, sizeof(pa), fnv);
  95         fnv &= (HPT_SIZE - 1);
  96         for (hpte = kd->vmst->hpt_head[fnv]; hpte != NULL; hpte = hpte->next) {
  97                 if (pa == hpte->pa)
  98                         return (hpte->off);
  99         }
 100         return (-1);
 101 }
 102
 103 static int
 104 inithash(kvm_t *kd, uint64_t *base, int len, off_t off)
 105 {
 106         uint64_t idx;
 107         uint64_t bit, bits;
 108         vm_paddr_t pa;
 109
 110         for (idx = 0; idx < len / sizeof(*base); idx++) {
 111                 bits = base[idx];
 112                 while (bits) {
 113                         bit = bsfq(bits);
 114                         bits &= ~(1ul << bit);
 115                         pa = (idx * sizeof(*base) * NBBY + bit) * PAGE_SIZE;
 116                         hpt_insert(kd, pa, off);
 117                         off += PAGE_SIZE;
 118                 }
 119         }
 120         return (off);
 121 }
 122
 123 void
 124 _kvm_minidump_freevtop(kvm_t *kd)
 125 {
 126         struct vmstate *vm = kd->vmst;
 127
 128         if (vm->bitmap)
 129                 free(vm->bitmap);
 130         if (vm->ptemap)
 131                 free(vm->ptemap);
 132         free(vm);
 133         kd->vmst = NULL;
 134 }
 135
 136 int
 137 _kvm_minidump_initvtop(kvm_t *kd)
 138 {
 139         u_long pa;
 140         struct vmstate *vmst;
 141         off_t off;
 142
 143         vmst = _kvm_malloc(kd, sizeof(*vmst));
 144         if (vmst == 0) {
 145                 _kvm_err(kd, kd->program, "cannot allocate vm");
 146                 return (-1);
 147         }
 148         kd->vmst = vmst;
 149         bzero(vmst, sizeof(*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             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             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
 199 static int
 200 _kvm_minidump_vatop(kvm_t *kd, u_long va, off_t *pa)
 201 {
 202         struct vmstate *vm;
 203         u_long offset;
 204         pt_entry_t pte;
 205         u_long pteindex;
 206         int i;
 207         u_long a;
 208         off_t ofs;
 209
 210         vm = kd->vmst;
 211         offset = va & (PAGE_SIZE - 1);
 212
 213         if (va >= vm->hdr.kernbase) {
 214                 pteindex = (va - vm->hdr.kernbase) >> PAGE_SHIFT;
 215                 pte = vm->ptemap[pteindex];
 216                 if (((u_long)pte & PG_V) == 0) {
 217                         _kvm_err(kd, kd->program, "_kvm_vatop: pte not valid");
 218                         goto invalid;
 219                 }
 220                 a = pte & PG_FRAME;
 221                 ofs = hpt_find(kd, a);
 222                 if (ofs == -1) {
 223                         _kvm_err(kd, kd->program, "_kvm_vatop: physical address 0x%lx not in minidump", a);
 224                         goto invalid;
 225                 }
 226                 *pa = ofs + offset;
 227                 return (PAGE_SIZE - offset);
 228         } else if (va >= vm->hdr.dmapbase && va < vm->hdr.dmapend) {
 229                 a = (va - vm->hdr.dmapbase) & ~PAGE_MASK;
 230                 ofs = hpt_find(kd, a);
 231                 if (ofs == -1) {
 232                         _kvm_err(kd, kd->program, "_kvm_vatop: direct map address 0x%lx not in minidump", va);
 233                         goto invalid;
 234                 }
 235                 *pa = ofs + offset;
 236                 return (PAGE_SIZE - offset);
 237         } else {
 238                 _kvm_err(kd, kd->program, "_kvm_vatop: virtual address 0x%lx not minidumped", va);
 239                 goto invalid;
 240         }
 241
 242 invalid:
 243         _kvm_err(kd, 0, "invalid address (0x%lx)", va);
 244         return (0);
 245 }
 246
 247 int
 248 _kvm_minidump_kvatop(kvm_t *kd, u_long va, off_t *pa)
 249 {
 250
 251         if (ISALIVE(kd)) {
 252                 _kvm_err(kd, 0, "kvm_kvatop called in live kernel!");
 253                 return (0);
 254         }
 255         return (_kvm_minidump_vatop(kd, va, pa));
 256 }