lib/libkvm/kvm_i386.c

   1 /*      $NetBSD: kvm_i386.c,v 1.30 2014/02/19 20:21:22 dsl Exp $        */
   2
   3 /*-
   4  * Copyright (c) 1989, 1992, 1993
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * This code is derived from software developed by the Computer Systems
   8  * Engineering group at Lawrence Berkeley Laboratory under DARPA contract
   9  * BG 91-66 and contributed to Berkeley.
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions and the following disclaimer.
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in the
  18  *    documentation and/or other materials provided with the distribution.
  19  * 3. Neither the name of the University nor the names of its contributors
  20  *    may be used to endorse or promote products derived from this software
  21  *    without specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  */
  35
  36 #include <sys/cdefs.h>
  37 #if defined(LIBC_SCCS) && !defined(lint)
  38 #if 0
  39 static char sccsid[] = "@(#)kvm_hp300.c 8.1 (Berkeley) 6/4/93";
  40 #else
  41 __RCSID("$NetBSD: kvm_i386.c,v 1.30 2014/02/19 20:21:22 dsl Exp $");
  42 #endif
  43 #endif /* LIBC_SCCS and not lint */
  44
  45 /*
  46  * i386 machine dependent routines for kvm.
  47  */
  48
  49 #include <sys/param.h>
  50 #include <sys/stat.h>
  51 #include <sys/kcore.h>
  52 #include <sys/types.h>
  53
  54 #include <stdlib.h>
  55 #include <unistd.h>
  56 #include <nlist.h>
  57 #include <kvm.h>
  58
  59 #include <uvm/uvm_extern.h>
  60
  61 #include <limits.h>
  62 #include <db.h>
  63
  64 #include "kvm_private.h"
  65
  66 #include <i386/kcore.h>
  67 #include <i386/pmap.h>
  68 #include <i386/pte.h>
  69 #include <i386/vmparam.h>
  70
  71 #ifndef btop
  72 #define btop(x)         (((unsigned)(x)) >> PGSHIFT)    /* XXX */
  73 #define ptob(x)         ((caddr_t)((x) << PGSHIFT))     /* XXX */
  74 #endif
  75
  76 /*
  77  * Indicates whether PAE is in use for the kernel image
  78  * 0: native i386 memory mappings
  79  * 1: i386 PAE mappings
  80  */
  81 static int i386_use_pae;
  82
  83 int _kvm_kvatop_i386(kvm_t *, vaddr_t, paddr_t *);
  84 int _kvm_kvatop_i386pae(kvm_t *, vaddr_t, paddr_t *);
  85
  86 void
  87 _kvm_freevtop(kvm_t *kd)
  88 {
  89
  90         /* Not actually used for anything right now, but safe. */
  91         if (kd->vmst != 0)
  92                 free(kd->vmst);
  93 }
  94
  95 /*ARGSUSED*/
  96 int
  97 _kvm_initvtop(kvm_t *kd)
  98 {
  99         cpu_kcore_hdr_t *cpu_kh = kd->cpu_data;
 100
 101         i386_use_pae = 0; /* default: non PAE mode */
 102         if ((cpu_kh->pdppaddr & I386_KCORE_PAE) == I386_KCORE_PAE)
 103                 i386_use_pae = 1;
 104
 105         return 0;
 106 }
 107
 108 /*
 109  * Translate a kernel virtual address to a physical address.
 110  */
 111 int
 112 _kvm_kvatop(kvm_t *kd, vaddr_t va, paddr_t *pa)
 113 {
 114
 115         if (ISALIVE(kd)) {
 116                 _kvm_err(kd, 0, "vatop called in live kernel!");
 117                 return 0;
 118         }
 119
 120         switch (i386_use_pae) {
 121         default:
 122         case 0:
 123                 return _kvm_kvatop_i386(kd, va, pa);
 124         case 1:
 125                 return _kvm_kvatop_i386pae(kd, va, pa);
 126         }
 127
 128 }
 129
 130 /*
 131  * Used to translate a virtual address to a physical address for systems
 132  * with PAE mode disabled. Only two levels of virtual memory pages are
 133  * dereferenced (L2 PDEs, then L1 PTEs).
 134  */
 135 int
 136 _kvm_kvatop_i386(kvm_t *kd, vaddr_t va, paddr_t *pa)
 137 {
 138         cpu_kcore_hdr_t *cpu_kh;
 139         u_long page_off;
 140         pd_entry_t pde;
 141         pt_entry_t pte;
 142         paddr_t pde_pa, pte_pa;
 143
 144         cpu_kh = kd->cpu_data;
 145         page_off = va & PGOFSET;
 146
 147         /*
 148          * Find and read the page directory entry.
 149          * pdppaddr being PAGE_SIZE aligned, we mask the option bits.
 150          */
 151         pde_pa = (cpu_kh->pdppaddr & PG_FRAME) + (pl2_pi(va) * sizeof(pde));
 152         if (_kvm_pread(kd, kd->pmfd, (void *)&pde, sizeof(pde),
 153             _kvm_pa2off(kd, pde_pa)) != sizeof(pde)) {
 154                 _kvm_syserr(kd, 0, "could not read PDE");
 155                 goto lose;
 156         }
 157
 158         /*
 159          * Find and read the page table entry.
 160          */
 161         if ((pde & PG_V) == 0) {
 162                 _kvm_err(kd, 0, "invalid translation (invalid PDE)");
 163                 goto lose;
 164         }
 165         if ((pde & PG_PS) != 0) {
 166                 /*
 167                  * This is a 4MB page.
 168                  */
 169                 page_off = va & ~PG_LGFRAME;
 170                 *pa = (pde & PG_LGFRAME) + page_off;
 171                 return (int)(NBPD_L2 - page_off);
 172         }
 173         pte_pa = (pde & PG_FRAME) + (pl1_pi(va) * sizeof(pt_entry_t));
 174         if (_kvm_pread(kd, kd->pmfd, (void *) &pte, sizeof(pte),
 175             _kvm_pa2off(kd, pte_pa)) != sizeof(pte)) {
 176                 _kvm_syserr(kd, 0, "could not read PTE");
 177                 goto lose;
 178         }
 179
 180         /*
 181          * Validate the PTE and return the physical address.
 182          */
 183         if ((pte & PG_V) == 0) {
 184                 _kvm_err(kd, 0, "invalid translation (invalid PTE)");
 185                 goto lose;
 186         }
 187         *pa = (pte & PG_FRAME) + page_off;
 188         return (int)(NBPG - page_off);
 189
 190  lose:
 191         *pa = (paddr_t)~0L;
 192         return 0;
 193 }
 194
 195 /*
 196  * Translate a physical address to a file-offset in the crash dump.
 197  */
 198 off_t
 199 _kvm_pa2off(kvm_t *kd, paddr_t pa)
 200 {
 201         cpu_kcore_hdr_t *cpu_kh;
 202         phys_ram_seg_t *ramsegs;
 203         off_t off;
 204         int i;
 205
 206         cpu_kh = kd->cpu_data;
 207         ramsegs = (void *)((char *)(void *)cpu_kh + ALIGN(sizeof *cpu_kh));
 208
 209         off = 0;
 210         for (i = 0; i < cpu_kh->nmemsegs; i++) {
 211                 if (pa >= ramsegs[i].start &&
 212                     (pa - ramsegs[i].start) < ramsegs[i].size) {
 213                         off += (pa - ramsegs[i].start);
 214                         break;
 215                 }
 216                 off += ramsegs[i].size;
 217         }
 218
 219         return (kd->dump_off + off);
 220 }
 221
 222 /*
 223  * Machine-dependent initialization for ALL open kvm descriptors,
 224  * not just those for a kernel crash dump.  Some architectures
 225  * have to deal with these NOT being constants!  (i.e. m68k)
 226  */
 227 int
 228 _kvm_mdopen(kvm_t *kd)
 229 {
 230
 231         kd->usrstack = USRSTACK;
 232         kd->min_uva = VM_MIN_ADDRESS;
 233         kd->max_uva = VM_MAXUSER_ADDRESS;
 234
 235         return 0;
 236 }