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. All advertising materials mentioning features or use of this software
  18  *    must display the following acknowledgement:
  19  *      This product includes software developed by the University of
  20  *      California, Berkeley and its contributors.
  21  * 4. Neither the name of the University nor the names of its contributors
  22  *    may be used to endorse or promote products derived from this software
  23  *    without specific prior written permission.
  24  *
  25  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  27  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  28  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  29  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  30  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  31  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  32  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  33  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  34  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  35  * SUCH DAMAGE.
  36  *
  37  * @(#)kvm_hp300.c      8.1 (Berkeley) 6/4/93
  38  * $FreeBSD: src/lib/libkvm/kvm_amd64.c,v 1.16 2003/04/30 21:05:33 peter Exp $
  39  */
  40
  41 /*
  42  * x86_64 machine dependent routines for kvm.  Hopefully, the forthcoming
  43  * vm code will one day obsolete this module.
  44  */
  45
  46 #include <sys/user.h>   /* MUST BE FIRST */
  47 #include <sys/param.h>
  48 #include <sys/proc.h>
  49 #include <sys/stat.h>
  50 #include <sys/mman.h>
  51 #include <sys/elf_common.h>
  52 #include <stdlib.h>
  53 #include <string.h>
  54 #include <unistd.h>
  55 #include <nlist.h>
  56 #include <kvm.h>
  57
  58 #include <vm/vm.h>
  59 #include <vm/vm_param.h>
  60
  61 #include <machine/elf.h>
  62
  63 #include <limits.h>
  64
  65 #include "kvm_private.h"
  66
  67 #ifndef btop
  68 #define btop(x)         (x86_64_btop(x))
  69 #define ptob(x)         (x86_64_ptob(x))
  70 #endif
  71
  72 struct vmstate {
  73         int             minidump;       /* 1 = minidump mode */
  74         void            *mmapbase;
  75         size_t          mmapsize;
  76         pml4_entry_t    *PML4;
  77 };
  78
  79 /*
  80  * Map the ELF headers into the process' address space. We do this in two
  81  * steps: first the ELF header itself and using that information the whole
  82  * set of headers. (Taken from kvm_ia64.c)
  83  */
  84 static int
  85 _kvm_maphdrs(kvm_t *kd, size_t sz)
  86 {
  87         struct vmstate *vm = kd->vmst;
  88
  89         if (kd->vmst->minidump) {
  90                 _kvm_minidump_freevtop(kd);
  91                 return (0);
  92         }
  93
  94         /* munmap() previous mmap(). */
  95         if (vm->mmapbase != NULL) {
  96                 munmap(vm->mmapbase, vm->mmapsize);
  97                 vm->mmapbase = NULL;
  98         }
  99
 100         vm->mmapsize = sz;
 101         vm->mmapbase = mmap(NULL, sz, PROT_READ, MAP_PRIVATE, kd->pmfd, 0);
 102         if (vm->mmapbase == MAP_FAILED) {
 103                 _kvm_err(kd, kd->program, "cannot mmap corefile");
 104                 return (-1);
 105         }
 106         return (0);
 107 }
 108
 109 /*
 110  * Translate a physical memory address to a file-offset in the crash-dump.
 111  * (Taken from kvm_ia64.c)
 112  */
 113 static size_t
 114 _kvm_pa2off(kvm_t *kd, uint64_t pa, off_t *ofs)
 115 {
 116         Elf_Ehdr *e = kd->vmst->mmapbase;
 117         Elf_Phdr *p;
 118         int n;
 119
 120         if (kd->rawdump) {
 121                 *ofs = pa;
 122                 return (PAGE_SIZE - ((size_t)pa & PAGE_MASK));
 123         }
 124
 125         p = (Elf_Phdr*)((char*)e + e->e_phoff);
 126         n = e->e_phnum;
 127
 128         while (n && (pa < p->p_paddr || pa >= p->p_paddr + p->p_memsz))
 129                 p++, n--;
 130         if (n == 0)
 131                 return (0);
 132         *ofs = (pa - p->p_paddr) + p->p_offset;
 133         return (PAGE_SIZE - ((size_t)pa & PAGE_MASK));
 134 }
 135
 136 void
 137 _kvm_freevtop(kvm_t *kd)
 138 {
 139         struct vmstate *vm = kd->vmst;
 140
 141         if (kd->vmst->minidump) {
 142                 _kvm_minidump_freevtop(kd);
 143                 return;
 144         }
 145
 146         if (vm->mmapbase != NULL)
 147                 munmap(vm->mmapbase, vm->mmapsize);
 148         if (vm->PML4)
 149                 free(vm->PML4);
 150         free(vm);
 151         kd->vmst = NULL;
 152 }
 153
 154 int
 155 _kvm_initvtop(kvm_t *kd)
 156 {
 157         struct nlist nlist[2];
 158         u_long pa;
 159         u_long kernbase;
 160         pml4_entry_t    *PML4;
 161         Elf_Ehdr *ehdr;
 162         size_t hdrsz;
 163         char    minihdr[8];
 164
 165         if (pread(kd->pmfd, &minihdr, 8, 0) == 8)
 166                 if (memcmp(&minihdr, "minidump", 8) == 0)
 167                         return (_kvm_minidump_initvtop(kd));
 168
 169         kd->vmst = (struct vmstate *)_kvm_malloc(kd, sizeof(*kd->vmst));
 170         if (kd->vmst == 0) {
 171                 _kvm_err(kd, kd->program, "cannot allocate vm");
 172                 return (-1);
 173         }
 174         kd->vmst->PML4 = 0;
 175
 176         if (_kvm_maphdrs(kd, sizeof(Elf_Ehdr)) == -1)
 177                 return (-1);
 178         /*
 179          * Check if this is indeed an ELF header. If not, assume old style dump or
 180          * memory layout.
 181          */
 182         ehdr = kd->vmst->mmapbase;
 183         if (!IS_ELF(*ehdr)) {
 184                 kd->rawdump = 1;
 185                 munmap(kd->vmst->mmapbase, kd->vmst->mmapsize);
 186                 kd->vmst->mmapbase = NULL;
 187         } else {
 188                 hdrsz = ehdr->e_phoff + ehdr->e_phentsize * ehdr->e_phnum;
 189                 if (_kvm_maphdrs(kd, hdrsz) == -1)
 190                         return (-1);
 191         }
 192
 193         nlist[0].n_name = "kernbase";
 194         nlist[1].n_name = 0;
 195
 196         if (kvm_nlist(kd, nlist) != 0) {
 197                 _kvm_err(kd, kd->program, "bad namelist - no kernbase");
 198                 return (-1);
 199         }
 200         kernbase = nlist[0].n_value;
 201
 202         nlist[0].n_name = "KPML4phys";
 203         nlist[1].n_name = 0;
 204
 205         if (kvm_nlist(kd, nlist) != 0) {
 206                 _kvm_err(kd, kd->program, "bad namelist - no KPML4phys");
 207                 return (-1);
 208         }
 209         if (kvm_read(kd, (nlist[0].n_value - kernbase), &pa, sizeof(pa)) !=
 210             sizeof(pa)) {
 211                 _kvm_err(kd, kd->program, "cannot read KPML4phys");
 212                 return (-1);
 213         }
 214         PML4 = _kvm_malloc(kd, PAGE_SIZE);
 215         if (kvm_read(kd, pa, PML4, PAGE_SIZE) != PAGE_SIZE) {
 216                 _kvm_err(kd, kd->program, "cannot read KPML4phys");
 217                 return (-1);
 218         }
 219         kd->vmst->PML4 = PML4;
 220         return (0);
 221 }
 222
 223 static int
 224 _kvm_vatop(kvm_t *kd, u_long va, off_t *pa)
 225 {
 226         struct vmstate *vm;
 227         u_long offset;
 228         u_long pdpe_pa;
 229         u_long pde_pa;
 230         u_long pte_pa;
 231         pml4_entry_t pml4e;
 232         pdp_entry_t pdpe;
 233         pd_entry_t pde;
 234         pt_entry_t pte;
 235         u_long pml4eindex;
 236         u_long pdpeindex;
 237         u_long pdeindex;
 238         u_long pteindex;
 239         u_long a;
 240         off_t ofs;
 241         size_t s;
 242
 243         vm = kd->vmst;
 244         offset = va & (PAGE_SIZE - 1);
 245
 246         /*
 247          * If we are initializing (kernel page table descriptor pointer
 248          * not yet set) then return pa == va to avoid infinite recursion.
 249          */
 250         if (vm->PML4 == 0) {
 251                 s = _kvm_pa2off(kd, va, pa);
 252                 if (s == 0) {
 253                         _kvm_err(kd, kd->program,
 254                             "_kvm_vatop: bootstrap data not in dump");
 255                         goto invalid;
 256                 } else
 257                         return (PAGE_SIZE - offset);
 258         }
 259
 260         pml4eindex = (va >> PML4SHIFT) & (NPML4EPG - 1);
 261         pml4e = vm->PML4[pml4eindex];
 262         if (((u_long)pml4e & PG_V) == 0) {
 263                 _kvm_err(kd, kd->program, "_kvm_vatop: pml4e not valid");
 264                 goto invalid;
 265         }
 266
 267         pdpeindex = (va >> PDPSHIFT) & (NPDPEPG-1);
 268         pdpe_pa = ((u_long)pml4e & PG_FRAME) +
 269             (pdpeindex * sizeof(pdp_entry_t));
 270
 271         s = _kvm_pa2off(kd, pdpe_pa, &ofs);
 272         if (s <= sizeof pdpe) {
 273                 _kvm_err(kd, kd->program, "_kvm_vatop: pdpe_pa not found");
 274                 goto invalid;
 275         }
 276         if (lseek(kd->pmfd, ofs, 0) == -1) {
 277                 _kvm_syserr(kd, kd->program, "_kvm_vatop: lseek pdpe_pa");
 278                 goto invalid;
 279         }
 280         if (read(kd->pmfd, &pdpe, sizeof pdpe) != sizeof pdpe) {
 281                 _kvm_syserr(kd, kd->program, "_kvm_vatop: read pdpe");
 282                 goto invalid;
 283         }
 284         if (((u_long)pdpe & PG_V) == 0) {
 285                 _kvm_err(kd, kd->program, "_kvm_vatop: pdpe not valid");
 286                 goto invalid;
 287         }
 288
 289
 290         pdeindex = (va >> PDRSHIFT) & (NPDEPG-1);
 291         pde_pa = ((u_long)pdpe & PG_FRAME) + (pdeindex * sizeof(pd_entry_t));
 292
 293         s = _kvm_pa2off(kd, pde_pa, &ofs);
 294         if (s <= sizeof pde) {
 295                 _kvm_syserr(kd, kd->program, "_kvm_vatop: pde_pa not found");
 296                 goto invalid;
 297         }
 298         if (lseek(kd->pmfd, ofs, 0) == -1) {
 299                 _kvm_err(kd, kd->program, "_kvm_vatop: lseek pde_pa");
 300                 goto invalid;
 301         }
 302         if (read(kd->pmfd, &pde, sizeof pde) != sizeof pde) {
 303                 _kvm_syserr(kd, kd->program, "_kvm_vatop: read pde");
 304                 goto invalid;
 305         }
 306         if (((u_long)pde & PG_V) == 0) {
 307                 _kvm_err(kd, kd->program, "_kvm_vatop: pde not valid");
 308                 goto invalid;
 309         }
 310
 311         if ((u_long)pde & PG_PS) {
 312               /*
 313                * No final-level page table; ptd describes one 2MB page.
 314                */
 315 #define PAGE2M_MASK     (NBPDR - 1)
 316 #define PG_FRAME2M      (~PAGE2M_MASK)
 317                 a = ((u_long)pde & PG_FRAME2M) + (va & PAGE2M_MASK);
 318                 s = _kvm_pa2off(kd, a, pa);
 319                 if (s == 0) {
 320                         _kvm_err(kd, kd->program,
 321                             "_kvm_vatop: 2MB page address not in dump");
 322                         goto invalid;
 323                 } else {
 324                         return (NBPDR - (va & PAGE2M_MASK));
 325                 }
 326         }
 327
 328         pteindex = (va >> PAGE_SHIFT) & (NPTEPG-1);
 329         pte_pa = ((u_long)pde & PG_FRAME) + (pteindex * sizeof(pt_entry_t));
 330
 331         s = _kvm_pa2off(kd, pte_pa, &ofs);
 332         if (s <= sizeof pte) {
 333                 _kvm_err(kd, kd->program, "_kvm_vatop: pte_pa not found");
 334                 goto invalid;
 335         }
 336         if (lseek(kd->pmfd, ofs, 0) == -1) {
 337                 _kvm_syserr(kd, kd->program, "_kvm_vatop: lseek");
 338                 goto invalid;
 339         }
 340         if (read(kd->pmfd, &pte, sizeof pte) != sizeof pte) {
 341                 _kvm_syserr(kd, kd->program, "_kvm_vatop: read");
 342                 goto invalid;
 343         }
 344         if (((u_long)pte & PG_V) == 0) {
 345                 _kvm_err(kd, kd->program, "_kvm_vatop: pte not valid");
 346                 goto invalid;
 347         }
 348
 349         a = ((u_long)pte & PG_FRAME) + offset;
 350         s = _kvm_pa2off(kd, a, pa);
 351         if (s == 0) {
 352                 _kvm_err(kd, kd->program, "_kvm_vatop: address not in dump");
 353                 goto invalid;
 354         } else
 355                 return (PAGE_SIZE - offset);
 356
 357 invalid:
 358         _kvm_err(kd, 0, "invalid address (0x%lx)", va);
 359         return (0);
 360 }
 361
 362 int
 363 _kvm_kvatop(kvm_t *kd, u_long va, off_t *pa)
 364 {
 365         if (kd->vmst->minidump)
 366                 return (_kvm_minidump_kvatop(kd, va, pa));
 367
 368         if (kvm_ishost(kd)) {
 369                 _kvm_err(kd, 0, "kvm_vatop called in live kernel!");
 370                 return((off_t)0);
 371         }
 372
 373         return (_kvm_vatop(kd, va, pa));
 374 }