lib/libkvm/kvm_x86_64.c

   1 /*-
   2  * Copyright (c) 1989, 1992, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * This code is derived from software developed by the Computer Systems
   6  * Engineering group at Lawrence Berkeley Laboratory under DARPA contract
   7  * BG 91-66 and contributed to Berkeley.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  * 3. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  *
  33  * @(#)kvm_hp300.c      8.1 (Berkeley) 6/4/93
  34  * $FreeBSD: src/lib/libkvm/kvm_amd64.c,v 1.16 2003/04/30 21:05:33 peter Exp $
  35  */
  36
  37 /*
  38  * x86_64 machine dependent routines for kvm.  Hopefully, the forthcoming
  39  * vm code will one day obsolete this module.
  40  */
  41
  42 #include <sys/user.h>   /* MUST BE FIRST */
  43 #include <sys/param.h>
  44 #include <sys/proc.h>
  45 #include <sys/stat.h>
  46 #include <sys/mman.h>
  47 #include <sys/elf_common.h>
  48 #include <stdlib.h>
  49 #include <string.h>
  50 #include <unistd.h>
  51 #include <nlist.h>
  52 #include <kvm.h>
  53
  54 #include <vm/vm.h>
  55 #include <vm/vm_param.h>
  56
  57 #include <machine/elf.h>
  58
  59 #include <limits.h>
  60
  61 #include "kvm_private.h"
  62
  63 #ifndef btop
  64 #define btop(x)         (x86_64_btop(x))
  65 #define ptob(x)         (x86_64_ptob(x))
  66 #endif
  67
  68 struct vmstate {
  69         int             minidump;       /* 1 = minidump mode */
  70         void            *mmapbase;
  71         size_t          mmapsize;
  72         pml4_entry_t    *PML4;
  73 };
  74
  75 /*
  76  * Map the ELF headers into the process' address space. We do this in two
  77  * steps: first the ELF header itself and using that information the whole
  78  * set of headers. (Taken from kvm_ia64.c)
  79  */
  80 static int
  81 _kvm_maphdrs(kvm_t *kd, size_t sz)
  82 {
  83         struct vmstate *vm = kd->vmst;
  84
  85         if (kd->vmst->minidump) {
  86                 _kvm_minidump_freevtop(kd);
  87                 return (0);
  88         }
  89
  90         /* munmap() previous mmap(). */
  91         if (vm->mmapbase != NULL) {
  92                 munmap(vm->mmapbase, vm->mmapsize);
  93                 vm->mmapbase = NULL;
  94         }
  95
  96         vm->mmapsize = sz;
  97         vm->mmapbase = mmap(NULL, sz, PROT_READ, MAP_PRIVATE, kd->pmfd, 0);
  98         if (vm->mmapbase == MAP_FAILED) {
  99                 _kvm_err(kd, kd->program, "cannot mmap corefile");
 100                 return (-1);
 101         }
 102         return (0);
 103 }
 104
 105 /*
 106  * Translate a physical memory address to a file-offset in the crash-dump.
 107  * (Taken from kvm_ia64.c)
 108  */
 109 static size_t
 110 _kvm_pa2off(kvm_t *kd, uint64_t pa, off_t *ofs)
 111 {
 112         Elf_Ehdr *e = kd->vmst->mmapbase;
 113         Elf_Phdr *p;
 114         int n;
 115
 116         if (kd->rawdump) {
 117                 *ofs = pa;
 118                 return (PAGE_SIZE - ((size_t)pa & PAGE_MASK));
 119         }
 120
 121         p = (Elf_Phdr*)((char*)e + e->e_phoff);
 122         n = e->e_phnum;
 123
 124         while (n && (pa < p->p_paddr || pa >= p->p_paddr + p->p_memsz))
 125                 p++, n--;
 126         if (n == 0)
 127                 return (0);
 128         *ofs = (pa - p->p_paddr) + p->p_offset;
 129         return (PAGE_SIZE - ((size_t)pa & PAGE_MASK));
 130 }
 131
 132 void
 133 _kvm_freevtop(kvm_t *kd)
 134 {
 135         struct vmstate *vm = kd->vmst;
 136
 137         if (kd->vmst->minidump) {
 138                 _kvm_minidump_freevtop(kd);
 139                 return;
 140         }
 141
 142         if (vm->mmapbase != NULL)
 143                 munmap(vm->mmapbase, vm->mmapsize);
 144         if (vm->PML4)
 145                 free(vm->PML4);
 146         free(vm);
 147         kd->vmst = NULL;
 148 }
 149
 150 int
 151 _kvm_initvtop(kvm_t *kd)
 152 {
 153         struct nlist nlist[2];
 154         u_long pa;
 155         u_long kernbase;
 156         pml4_entry_t    *PML4;
 157         Elf_Ehdr *ehdr;
 158         size_t hdrsz;
 159         char    minihdr[8];
 160         struct pcb dumppcb;
 161
 162         if (pread(kd->pmfd, &minihdr, 8, 0) == 8)
 163                 if (memcmp(&minihdr, "minidump", 8) == 0)
 164                         return (_kvm_minidump_initvtop(kd));
 165
 166         kd->vmst = (struct vmstate *)_kvm_malloc(kd, sizeof(*kd->vmst));
 167         if (kd->vmst == 0) {
 168                 _kvm_err(kd, kd->program, "cannot allocate vm");
 169                 return (-1);
 170         }
 171         kd->vmst->PML4 = 0;
 172
 173         if (_kvm_maphdrs(kd, sizeof(Elf_Ehdr)) == -1)
 174                 return (-1);
 175         /*
 176          * Check if this is indeed an ELF header. If not, assume old style
 177           *dump or memory layout.
 178          */
 179         ehdr = kd->vmst->mmapbase;
 180         if (!IS_ELF(*ehdr)) {
 181                 kd->rawdump = 1;
 182                 munmap(kd->vmst->mmapbase, kd->vmst->mmapsize);
 183                 kd->vmst->mmapbase = NULL;
 184         } else {
 185                 hdrsz = ehdr->e_phoff + ehdr->e_phentsize * ehdr->e_phnum;
 186                 if (_kvm_maphdrs(kd, hdrsz) == -1)
 187                         return (-1);
 188         }
 189
 190         nlist[0].n_name = "kernbase";
 191         nlist[1].n_name = 0;
 192
 193         if (kvm_nlist(kd, nlist) != 0) {
 194                 _kvm_err(kd, kd->program, "bad namelist - no kernbase");
 195                 return (-1);
 196         }
 197         kernbase = nlist[0].n_value;
 198
 199         nlist[0].n_name = "dumppcb";
 200         nlist[1].n_name = 0;
 201
 202         if (kvm_nlist(kd, nlist) != 0) {
 203                 _kvm_err(kd, kd->program, "bad namelist - no dumppcb");
 204                 return (-1);
 205         }
 206         if (kvm_read(kd, (nlist[0].n_value - kernbase), &dumppcb,
 207                      sizeof(dumppcb)) != sizeof(dumppcb)) {
 208                 _kvm_err(kd, kd->program, "cannot read dumppcb");
 209                 return (-1);
 210         }
 211         pa = dumppcb.pcb_cr3 & PG_FRAME;
 212
 213         PML4 = _kvm_malloc(kd, PAGE_SIZE);
 214         if (kvm_read(kd, pa, PML4, PAGE_SIZE) != PAGE_SIZE) {
 215                 _kvm_err(kd, kd->program, "cannot read dumppcb");
 216                 return (-1);
 217         }
 218         kd->vmst->PML4 = PML4;
 219         return (0);
 220 }
 221
 222 static int
 223 _kvm_vatop(kvm_t *kd, u_long va, off_t *pa)
 224 {
 225         struct vmstate *vm;
 226         u_long offset;
 227         u_long pdpe_pa;
 228         u_long pde_pa;
 229         u_long pte_pa;
 230         pml4_entry_t pml4e;
 231         pdp_entry_t pdpe;
 232         pd_entry_t pde;
 233         pt_entry_t pte;
 234         u_long pml4eindex;
 235         u_long pdpeindex;
 236         u_long pdeindex;
 237         u_long pteindex;
 238         u_long a;
 239         off_t ofs;
 240         size_t s;
 241
 242         vm = kd->vmst;
 243         offset = va & (PAGE_SIZE - 1);
 244
 245         /*
 246          * If we are initializing (kernel page table descriptor pointer
 247          * not yet set) then return pa == va to avoid infinite recursion.
 248          */
 249         if (vm->PML4 == NULL) {
 250                 s = _kvm_pa2off(kd, va, pa);
 251                 if (s == 0) {
 252                         _kvm_err(kd, kd->program,
 253                             "_kvm_vatop: bootstrap data not in dump");
 254                         goto invalid;
 255                 } else
 256                         return (PAGE_SIZE - offset);
 257         }
 258
 259         pml4eindex = (va >> PML4SHIFT) & (NPML4EPG - 1);
 260         pml4e = vm->PML4[pml4eindex];
 261         if (((u_long)pml4e & X86_PG_V) == 0) {
 262                 _kvm_err(kd, kd->program, "_kvm_vatop: pml4e not valid");
 263                 goto invalid;
 264         }
 265
 266         pdpeindex = (va >> PDPSHIFT) & (NPDPEPG-1);
 267         pdpe_pa = ((u_long)pml4e & PG_FRAME) +
 268             (pdpeindex * sizeof(pdp_entry_t));
 269
 270         s = _kvm_pa2off(kd, pdpe_pa, &ofs);
 271         if (s < sizeof pdpe) {
 272                 _kvm_err(kd, kd->program, "_kvm_vatop: pdpe_pa not found");
 273                 goto invalid;
 274         }
 275         if (lseek(kd->pmfd, ofs, 0) == -1) {
 276                 _kvm_syserr(kd, kd->program, "_kvm_vatop: lseek pdpe_pa");
 277                 goto invalid;
 278         }
 279         if (read(kd->pmfd, &pdpe, sizeof pdpe) != sizeof pdpe) {
 280                 _kvm_syserr(kd, kd->program, "_kvm_vatop: read pdpe");
 281                 goto invalid;
 282         }
 283         if (((u_long)pdpe & X86_PG_V) == 0) {
 284                 _kvm_err(kd, kd->program, "_kvm_vatop: pdpe not valid");
 285                 goto invalid;
 286         }
 287
 288         pdeindex = (va >> PDRSHIFT) & (NPDEPG-1);
 289         pde_pa = ((u_long)pdpe & PG_FRAME) + (pdeindex * sizeof(pd_entry_t));
 290
 291         s = _kvm_pa2off(kd, pde_pa, &ofs);
 292         if (s < sizeof pde) {
 293                 _kvm_syserr(kd, kd->program, "_kvm_vatop: pde_pa not found");
 294                 goto invalid;
 295         }
 296         if (lseek(kd->pmfd, ofs, 0) == -1) {
 297                 _kvm_err(kd, kd->program, "_kvm_vatop: lseek pde_pa");
 298                 goto invalid;
 299         }
 300         if (read(kd->pmfd, &pde, sizeof pde) != sizeof pde) {
 301                 _kvm_syserr(kd, kd->program, "_kvm_vatop: read pde");
 302                 goto invalid;
 303         }
 304         if (((u_long)pde & X86_PG_V) == 0) {
 305                 _kvm_err(kd, kd->program, "_kvm_vatop: pde not valid");
 306                 goto invalid;
 307         }
 308
 309         if ((u_long)pde & X86_PG_PS) {
 310               /*
 311                * No final-level page table; ptd describes one 2MB page.
 312                */
 313 #define PAGE2M_MASK     (NBPDR - 1)
 314 #define PG_FRAME2M      (~PAGE2M_MASK)
 315                 a = ((u_long)pde & PG_FRAME2M) + (va & PAGE2M_MASK);
 316                 s = _kvm_pa2off(kd, a, pa);
 317                 if (s == 0) {
 318                         _kvm_err(kd, kd->program,
 319                             "_kvm_vatop: 2MB page address not in dump");
 320                         goto invalid;
 321                 } else {
 322                         return (NBPDR - (va & PAGE2M_MASK));
 323                 }
 324         }
 325
 326         pteindex = (va >> PAGE_SHIFT) & (NPTEPG-1);
 327         pte_pa = ((u_long)pde & PG_FRAME) + (pteindex * sizeof(pt_entry_t));
 328
 329         s = _kvm_pa2off(kd, pte_pa, &ofs);
 330         if (s < sizeof pte) {
 331                 _kvm_err(kd, kd->program, "_kvm_vatop: pte_pa not found");
 332                 goto invalid;
 333         }
 334         if (lseek(kd->pmfd, ofs, 0) == -1) {
 335                 _kvm_syserr(kd, kd->program, "_kvm_vatop: lseek");
 336                 goto invalid;
 337         }
 338         if (read(kd->pmfd, &pte, sizeof pte) != sizeof pte) {
 339                 _kvm_syserr(kd, kd->program, "_kvm_vatop: read");
 340                 goto invalid;
 341         }
 342         if (((u_long)pte & X86_PG_V) == 0) {
 343                 _kvm_err(kd, kd->program, "_kvm_vatop: pte not valid");
 344                 goto invalid;
 345         }
 346
 347         a = ((u_long)pte & PG_FRAME) + offset;
 348         s = _kvm_pa2off(kd, a, pa);
 349         if (s == 0) {
 350                 _kvm_err(kd, kd->program, "_kvm_vatop: address not in dump");
 351                 goto invalid;
 352         } else
 353                 return (PAGE_SIZE - offset);
 354
 355 invalid:
 356         _kvm_err(kd, 0, "invalid address (0x%lx)", va);
 357         return (0);
 358 }
 359
 360 int
 361 _kvm_kvatop(kvm_t *kd, u_long va, off_t *pa)
 362 {
 363         if (kd->vmst->minidump)
 364                 return (_kvm_minidump_kvatop(kd, va, pa));
 365
 366         if (kvm_ishost(kd)) {
 367                 _kvm_err(kd, 0, "kvm_vatop called in live kernel!");
 368                 return((off_t)0);
 369         }
 370
 371         return (_kvm_vatop(kd, va, pa));
 372 }