freebsd-skq/lib/libkvm/kvm_amd64.c
peter 2ed8e17b91 Implement virtual-to-physical address mapping for the kvm library on
dead kernel debugging.  The previous code was a "do nothing".

The most obvious side effect of this is that you can now do things like
this and reasonably expect them to work:
  dmesg -M /var/crash/vmcore.3 -N /var/crash/kernel.3
  ps -axl -M /var/crash/vmcore.3 -N /var/crash/kernel.3

A good deal of this was lifted from the gdb code to do this, as well as
from NetBSD's libkvm (which has completely different VM macros)
1996-10-07 20:17:50 +00:00

182 lines
4.8 KiB
C

/*-
* Copyright (c) 1989, 1992, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software developed by the Computer Systems
* Engineering group at Lawrence Berkeley Laboratory under DARPA contract
* BG 91-66 and contributed to Berkeley.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)kvm_hp300.c 8.1 (Berkeley) 6/4/93";
#endif /* LIBC_SCCS and not lint */
/*
* i386 machine dependent routines for kvm. Hopefully, the forthcoming
* vm code will one day obsolete this module.
*/
#include <sys/param.h>
#include <sys/user.h>
#include <sys/proc.h>
#include <sys/stat.h>
#include <stdlib.h>
#include <unistd.h>
#include <nlist.h>
#include <kvm.h>
#include <vm/vm.h>
#include <vm/vm_param.h>
#include <limits.h>
#include <db.h>
#include "kvm_private.h"
#ifndef btop
#define btop(x) (i386_btop(x))
#define ptob(x) (i386_ptob(x))
#endif
struct vmstate {
pd_entry_t *PTD;
};
void
_kvm_freevtop(kvm_t *kd)
{
if (kd->vmst != 0) {
if (kd->vmst->PTD) {
free(kd->vmst->PTD);
}
free(kd->vmst);
}
}
int
_kvm_initvtop(kvm_t *kd)
{
struct vmstate *vm;
struct nlist nlist[2];
u_long pa;
pd_entry_t *PTD;
vm = (struct vmstate *)_kvm_malloc(kd, sizeof(*vm));
if (vm == 0) {
_kvm_err(kd, kd->program, "cannot allocate vm");
return (-1);
}
kd->vmst = vm;
vm->PTD = 0;
nlist[0].n_name = "_IdlePTD";
nlist[1].n_name = 0;
if (kvm_nlist(kd, nlist) != 0) {
_kvm_err(kd, kd->program, "bad namelist");
return (-1);
}
if (kvm_read(kd, (nlist[0].n_value - KERNBASE), &pa, sizeof(pa)) != sizeof(pa)) {
_kvm_err(kd, kd->program, "cannot read IdlePTD");
return (-1);
}
PTD = _kvm_malloc(kd, PAGE_SIZE);
if (kvm_read(kd, pa, PTD, PAGE_SIZE) != PAGE_SIZE) {
_kvm_err(kd, kd->program, "cannot read PTD");
return (-1);
}
vm->PTD = PTD;
return (0);
}
static int
_kvm_vatop(kvm_t *kd, u_long va, u_long *pa)
{
struct vmstate *vm;
u_long offset;
u_long pte_pa;
pd_entry_t pde;
pt_entry_t pte;
u_long pdeindex;
u_long pteindex;
int i;
if (ISALIVE(kd)) {
_kvm_err(kd, 0, "vatop called in live kernel!");
return((off_t)0);
}
vm = kd->vmst;
offset = va & (PAGE_SIZE - 1);
/*
* If we are initializing (kernel page table descriptor pointer
* not yet set) then return pa == va to avoid infinite recursion.
*/
if (vm->PTD == 0) {
*pa = va;
return (PAGE_SIZE - offset);
}
pdeindex = va >> PDRSHIFT;
pde = vm->PTD[pdeindex];
if (((u_long)pde & PG_V) == 0)
goto invalid;
pteindex = (va >> PAGE_SHIFT) & (NPTEPG-1);
pte_pa = ((u_long)pde & PG_FRAME) + (pteindex * sizeof(pt_entry_t));
/* XXX This has to be a physical address read, kvm_read is virtual */
if (lseek(kd->pmfd, pte_pa, 0) == -1) {
_kvm_syserr(kd, kd->program, "_kvm_vatop: lseek");
goto invalid;
}
if (read(kd->pmfd, &pte, sizeof pte) != sizeof pte) {
_kvm_syserr(kd, kd->program, "_kvm_vatop: read");
goto invalid;
}
if (((u_long)pte & PG_V) == 0)
goto invalid;
*pa = ((u_long)pte & PG_FRAME) + offset;
return (PAGE_SIZE - offset);
invalid:
_kvm_err(kd, 0, "invalid address (%x)", va);
return (0);
}
int
_kvm_kvatop(kvm_t *kd, u_long va, u_long *pa)
{
return (_kvm_vatop(kd, va, pa));
}