1
0
mirror of https://git.FreeBSD.org/src.git synced 2024-12-24 11:29:10 +00:00
freebsd/lib/libkvm/kvm_amd64.c
Peter Wemm add112ff65 Fix a well duplicated fencepost error that stopped crashdumps being
readable on certain random memory configurations.  If the libkvm consumer
tried to read something that was in the very last pdpe, pde or pte slot,
it would bogusly fail.

This is broken in RELENG_6 too.
2005-10-20 05:41:38 +00:00

342 lines
8.8 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#if defined(LIBC_SCCS) && !defined(lint)
#if 0
static char sccsid[] = "@(#)kvm_hp300.c 8.1 (Berkeley) 6/4/93";
#endif
#endif /* LIBC_SCCS and not lint */
/*
* AMD64 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 <sys/mman.h>
#include <stdlib.h>
#include <unistd.h>
#include <nlist.h>
#include <kvm.h>
#include <vm/vm.h>
#include <vm/vm_param.h>
#include <machine/elf.h>
#include <limits.h>
#include "kvm_private.h"
#ifndef btop
#define btop(x) (amd64_btop(x))
#define ptob(x) (amd64_ptob(x))
#endif
struct vmstate {
void *mmapbase;
size_t mmapsize;
pml4_entry_t *PML4;
};
/*
* Map the ELF headers into the process' address space. We do this in two
* steps: first the ELF header itself and using that information the whole
* set of headers. (Taken from kvm_ia64.c)
*/
static int
_kvm_maphdrs(kvm_t *kd, size_t sz)
{
struct vmstate *vm = kd->vmst;
/* munmap() previous mmap(). */
if (vm->mmapbase != NULL) {
munmap(vm->mmapbase, vm->mmapsize);
vm->mmapbase = NULL;
}
vm->mmapsize = sz;
vm->mmapbase = mmap(NULL, sz, PROT_READ, MAP_PRIVATE, kd->pmfd, 0);
if (vm->mmapbase == MAP_FAILED) {
_kvm_err(kd, kd->program, "cannot mmap corefile");
return (-1);
}
return (0);
}
/*
* Translate a physical memory address to a file-offset in the crash-dump.
* (Taken from kvm_ia64.c)
*/
static size_t
_kvm_pa2off(kvm_t *kd, uint64_t pa, off_t *ofs)
{
Elf_Ehdr *e = kd->vmst->mmapbase;
Elf_Phdr *p = (Elf_Phdr*)((char*)e + e->e_phoff);
int n = e->e_phnum;
while (n && (pa < p->p_paddr || pa >= p->p_paddr + p->p_memsz))
p++, n--;
if (n == 0)
return (0);
*ofs = (pa - p->p_paddr) + p->p_offset;
return (PAGE_SIZE - ((size_t)pa & PAGE_MASK));
}
void
_kvm_freevtop(kvm_t *kd)
{
struct vmstate *vm = kd->vmst;
if (vm->mmapbase != NULL)
munmap(vm->mmapbase, vm->mmapsize);
if (vm->PML4)
free(vm->PML4);
free(vm);
kd->vmst = NULL;
}
int
_kvm_initvtop(kvm_t *kd)
{
struct nlist nlist[2];
u_long pa;
u_long kernbase;
pml4_entry_t *PML4;
Elf_Ehdr *ehdr;
size_t hdrsz;
kd->vmst = (struct vmstate *)_kvm_malloc(kd, sizeof(*kd->vmst));
if (kd->vmst == 0) {
_kvm_err(kd, kd->program, "cannot allocate vm");
return (-1);
}
kd->vmst->PML4 = 0;
if (_kvm_maphdrs(kd, sizeof(Elf_Ehdr)) == -1)
return (-1);
ehdr = kd->vmst->mmapbase;
hdrsz = ehdr->e_phoff + ehdr->e_phentsize * ehdr->e_phnum;
if (_kvm_maphdrs(kd, hdrsz) == -1)
return (-1);
nlist[0].n_name = "kernbase";
nlist[1].n_name = 0;
if (kvm_nlist(kd, nlist) != 0) {
_kvm_err(kd, kd->program, "bad namelist - no kernbase");
return (-1);
}
kernbase = nlist[0].n_value;
nlist[0].n_name = "KPML4phys";
nlist[1].n_name = 0;
if (kvm_nlist(kd, nlist) != 0) {
_kvm_err(kd, kd->program, "bad namelist - no KPML4phys");
return (-1);
}
if (kvm_read(kd, (nlist[0].n_value - kernbase), &pa, sizeof(pa)) !=
sizeof(pa)) {
_kvm_err(kd, kd->program, "cannot read KPML4phys");
return (-1);
}
PML4 = _kvm_malloc(kd, PAGE_SIZE);
if (kvm_read(kd, pa, PML4, PAGE_SIZE) != PAGE_SIZE) {
_kvm_err(kd, kd->program, "cannot read KPML4phys");
return (-1);
}
kd->vmst->PML4 = PML4;
return (0);
}
static int
_kvm_vatop(kvm_t *kd, u_long va, off_t *pa)
{
struct vmstate *vm;
u_long offset;
u_long pdpe_pa;
u_long pde_pa;
u_long pte_pa;
pml4_entry_t pml4e;
pdp_entry_t pdpe;
pd_entry_t pde;
pt_entry_t pte;
u_long pml4eindex;
u_long pdpeindex;
u_long pdeindex;
u_long pteindex;
int i;
u_long a;
off_t ofs;
size_t s;
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->PML4 == 0) {
s = _kvm_pa2off(kd, va, pa);
if (s == 0) {
_kvm_err(kd, kd->program,
"_kvm_vatop: bootstrap data not in dump");
goto invalid;
} else
return (PAGE_SIZE - offset);
}
pml4eindex = (va >> PML4SHIFT) & (NPML4EPG - 1);
pml4e = vm->PML4[pml4eindex];
if (((u_long)pml4e & PG_V) == 0) {
_kvm_err(kd, kd->program, "_kvm_vatop: pml4e not valid");
goto invalid;
}
pdpeindex = (va >> PDPSHIFT) & (NPDPEPG-1);
pdpe_pa = ((u_long)pml4e & PG_FRAME) +
(pdpeindex * sizeof(pdp_entry_t));
s = _kvm_pa2off(kd, pdpe_pa, &ofs);
if (s < sizeof pdpe) {
_kvm_err(kd, kd->program, "_kvm_vatop: pdpe_pa not found");
goto invalid;
}
if (lseek(kd->pmfd, ofs, 0) == -1) {
_kvm_syserr(kd, kd->program, "_kvm_vatop: lseek pdpe_pa");
goto invalid;
}
if (read(kd->pmfd, &pdpe, sizeof pdpe) != sizeof pdpe) {
_kvm_syserr(kd, kd->program, "_kvm_vatop: read pdpe");
goto invalid;
}
if (((u_long)pdpe & PG_V) == 0) {
_kvm_err(kd, kd->program, "_kvm_vatop: pdpe not valid");
goto invalid;
}
pdeindex = (va >> PDRSHIFT) & (NPDEPG-1);
pde_pa = ((u_long)pdpe & PG_FRAME) + (pdeindex * sizeof(pd_entry_t));
s = _kvm_pa2off(kd, pde_pa, &ofs);
if (s < sizeof pde) {
_kvm_syserr(kd, kd->program, "_kvm_vatop: pde_pa not found");
goto invalid;
}
if (lseek(kd->pmfd, ofs, 0) == -1) {
_kvm_err(kd, kd->program, "_kvm_vatop: lseek pde_pa");
goto invalid;
}
if (read(kd->pmfd, &pde, sizeof pde) != sizeof pde) {
_kvm_syserr(kd, kd->program, "_kvm_vatop: read pde");
goto invalid;
}
if (((u_long)pde & PG_V) == 0) {
_kvm_err(kd, kd->program, "_kvm_vatop: pde not valid");
goto invalid;
}
if ((u_long)pde & PG_PS) {
/*
* No final-level page table; ptd describes one 2MB page.
*/
#define PAGE2M_MASK (NBPDR - 1)
#define PG_FRAME2M (~PAGE2M_MASK)
a = ((u_long)pde & PG_FRAME2M) + (va & PAGE2M_MASK);
s = _kvm_pa2off(kd, a, pa);
if (s == 0) {
_kvm_err(kd, kd->program,
"_kvm_vatop: 2MB page address not in dump");
goto invalid;
} else
return (NBPDR - (va & PAGE2M_MASK));
}
pteindex = (va >> PAGE_SHIFT) & (NPTEPG-1);
pte_pa = ((u_long)pde & PG_FRAME) + (pteindex * sizeof(pt_entry_t));
s = _kvm_pa2off(kd, pte_pa, &ofs);
if (s < sizeof pte) {
_kvm_err(kd, kd->program, "_kvm_vatop: pte_pa not found");
goto invalid;
}
if (lseek(kd->pmfd, ofs, 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) {
_kvm_err(kd, kd->program, "_kvm_vatop: pte not valid");
goto invalid;
}
a = ((u_long)pte & PG_FRAME) + offset;
s = _kvm_pa2off(kd, a, pa);
if (s == 0) {
_kvm_err(kd, kd->program, "_kvm_vatop: address not in dump");
goto invalid;
} else
return (PAGE_SIZE - offset);
invalid:
_kvm_err(kd, 0, "invalid address (0x%lx)", va);
return (0);
}
int
_kvm_kvatop(kvm_t *kd, u_long va, off_t *pa)
{
if (ISALIVE(kd)) {
_kvm_err(kd, 0, "kvm_kvatop called in live kernel!");
return (0);
}
return (_kvm_vatop(kd, va, pa));
}