freebsd-dev/lib/libkvm/kvm_minidump_i386.c
Mark Johnston b957b18594 Always use 64-bit physical addresses for dump_avail[] in minidumps
As of r365978, minidumps include a copy of dump_avail[].  This is an
array of vm_paddr_t ranges.  libkvm walks the array assuming that
sizeof(vm_paddr_t) is equal to the platform "word size", but that's not
correct on some platforms.  For instance, i386 uses a 64-bit vm_paddr_t.

Fix the problem by always dumping 64-bit addresses.  On platforms where
vm_paddr_t is 32 bits wide, namely arm and mips (sometimes), translate
dump_avail[] to an array of uint64_t ranges.  With this change, libkvm
no longer needs to maintain a notion of the target word size, so get rid
of it.

This is a no-op on platforms where sizeof(vm_paddr_t) == 8.

Reviewed by:	alc, kib
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D27082
2020-12-03 17:12:31 +00:00

347 lines
8.6 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2006 Peter Wemm
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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("$FreeBSD$");
/*
* i386 machine dependent routines for kvm and minidumps.
*/
#include <sys/param.h>
#include <sys/endian.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <vm/vm.h>
#include <kvm.h>
#include "../../sys/i386/include/minidump.h"
#include <limits.h>
#include "kvm_private.h"
#include "kvm_i386.h"
#define i386_round_page(x) roundup2((kvaddr_t)(x), I386_PAGE_SIZE)
struct vmstate {
struct minidumphdr hdr;
};
static i386_pte_pae_t
_i386_pte_pae_get(kvm_t *kd, u_long pteindex)
{
i386_pte_pae_t *pte = _kvm_pmap_get(kd, pteindex, sizeof(*pte));
return le64toh(*pte);
}
static i386_pte_t
_i386_pte_get(kvm_t *kd, u_long pteindex)
{
i386_pte_t *pte = _kvm_pmap_get(kd, pteindex, sizeof(*pte));
return le32toh(*pte);
}
static int
_i386_minidump_probe(kvm_t *kd)
{
return (_kvm_probe_elf_kernel(kd, ELFCLASS32, EM_386) &&
_kvm_is_minidump(kd));
}
static void
_i386_minidump_freevtop(kvm_t *kd)
{
struct vmstate *vm = kd->vmst;
free(vm);
kd->vmst = NULL;
}
static int
_i386_minidump_initvtop(kvm_t *kd)
{
struct vmstate *vmst;
off_t off, dump_avail_off, sparse_off;
vmst = _kvm_malloc(kd, sizeof(*vmst));
if (vmst == NULL) {
_kvm_err(kd, kd->program, "cannot allocate vm");
return (-1);
}
kd->vmst = vmst;
if (pread(kd->pmfd, &vmst->hdr, sizeof(vmst->hdr), 0) !=
sizeof(vmst->hdr)) {
_kvm_err(kd, kd->program, "cannot read dump header");
return (-1);
}
if (strncmp(MINIDUMP_MAGIC, vmst->hdr.magic, sizeof(vmst->hdr.magic)) != 0) {
_kvm_err(kd, kd->program, "not a minidump for this platform");
return (-1);
}
vmst->hdr.version = le32toh(vmst->hdr.version);
if (vmst->hdr.version != MINIDUMP_VERSION && vmst->hdr.version != 1) {
_kvm_err(kd, kd->program, "wrong minidump version. expected %d got %d",
MINIDUMP_VERSION, vmst->hdr.version);
return (-1);
}
vmst->hdr.msgbufsize = le32toh(vmst->hdr.msgbufsize);
vmst->hdr.bitmapsize = le32toh(vmst->hdr.bitmapsize);
vmst->hdr.ptesize = le32toh(vmst->hdr.ptesize);
vmst->hdr.kernbase = le32toh(vmst->hdr.kernbase);
vmst->hdr.paemode = le32toh(vmst->hdr.paemode);
vmst->hdr.dumpavailsize = vmst->hdr.version == MINIDUMP_VERSION ?
le32toh(vmst->hdr.dumpavailsize) : 0;
/* Skip header and msgbuf */
dump_avail_off = I386_PAGE_SIZE + i386_round_page(vmst->hdr.msgbufsize);
/* Skip dump_avail */
off = dump_avail_off + i386_round_page(vmst->hdr.dumpavailsize);
sparse_off = off + i386_round_page(vmst->hdr.bitmapsize) +
i386_round_page(vmst->hdr.ptesize);
if (_kvm_pt_init(kd, vmst->hdr.dumpavailsize, dump_avail_off,
vmst->hdr.bitmapsize, off, sparse_off, I386_PAGE_SIZE) == -1) {
return (-1);
}
off += i386_round_page(vmst->hdr.bitmapsize);
if (_kvm_pmap_init(kd, vmst->hdr.ptesize, off) == -1) {
return (-1);
}
off += i386_round_page(vmst->hdr.ptesize);
return (0);
}
static int
_i386_minidump_vatop_pae(kvm_t *kd, kvaddr_t va, off_t *pa)
{
struct vmstate *vm;
i386_physaddr_pae_t offset;
i386_pte_pae_t pte;
kvaddr_t pteindex;
i386_physaddr_pae_t a;
off_t ofs;
vm = kd->vmst;
offset = va & I386_PAGE_MASK;
if (va >= vm->hdr.kernbase) {
pteindex = (va - vm->hdr.kernbase) >> I386_PAGE_SHIFT;
if (pteindex >= vm->hdr.ptesize / sizeof(pte))
goto invalid;
pte = _i386_pte_pae_get(kd, pteindex);
if ((pte & I386_PG_V) == 0) {
_kvm_err(kd, kd->program,
"_i386_minidump_vatop_pae: pte not valid");
goto invalid;
}
a = pte & I386_PG_FRAME_PAE;
ofs = _kvm_pt_find(kd, a, I386_PAGE_SIZE);
if (ofs == -1) {
_kvm_err(kd, kd->program,
"_i386_minidump_vatop_pae: physical address 0x%jx not in minidump",
(uintmax_t)a);
goto invalid;
}
*pa = ofs + offset;
return (I386_PAGE_SIZE - offset);
} else {
_kvm_err(kd, kd->program,
"_i386_minidump_vatop_pae: virtual address 0x%jx not minidumped",
(uintmax_t)va);
goto invalid;
}
invalid:
_kvm_err(kd, 0, "invalid address (0x%jx)", (uintmax_t)va);
return (0);
}
static int
_i386_minidump_vatop(kvm_t *kd, kvaddr_t va, off_t *pa)
{
struct vmstate *vm;
i386_physaddr_t offset;
i386_pte_t pte;
kvaddr_t pteindex;
i386_physaddr_t a;
off_t ofs;
vm = kd->vmst;
offset = va & I386_PAGE_MASK;
if (va >= vm->hdr.kernbase) {
pteindex = (va - vm->hdr.kernbase) >> I386_PAGE_SHIFT;
if (pteindex >= vm->hdr.ptesize / sizeof(pte))
goto invalid;
pte = _i386_pte_get(kd, pteindex);
if ((pte & I386_PG_V) == 0) {
_kvm_err(kd, kd->program,
"_i386_minidump_vatop: pte not valid");
goto invalid;
}
a = pte & I386_PG_FRAME;
ofs = _kvm_pt_find(kd, a, I386_PAGE_SIZE);
if (ofs == -1) {
_kvm_err(kd, kd->program,
"_i386_minidump_vatop: physical address 0x%jx not in minidump",
(uintmax_t)a);
goto invalid;
}
*pa = ofs + offset;
return (I386_PAGE_SIZE - offset);
} else {
_kvm_err(kd, kd->program,
"_i386_minidump_vatop: virtual address 0x%jx not minidumped",
(uintmax_t)va);
goto invalid;
}
invalid:
_kvm_err(kd, 0, "invalid address (0x%jx)", (uintmax_t)va);
return (0);
}
static int
_i386_minidump_kvatop(kvm_t *kd, kvaddr_t va, off_t *pa)
{
if (ISALIVE(kd)) {
_kvm_err(kd, 0, "_i386_minidump_kvatop called in live kernel!");
return (0);
}
if (kd->vmst->hdr.paemode)
return (_i386_minidump_vatop_pae(kd, va, pa));
else
return (_i386_minidump_vatop(kd, va, pa));
}
static vm_prot_t
_i386_entry_to_prot(uint64_t pte)
{
vm_prot_t prot = VM_PROT_READ;
/* Source: i386/pmap.c:pmap_protect() */
if (pte & I386_PG_RW)
prot |= VM_PROT_WRITE;
if ((pte & I386_PG_NX) == 0)
prot |= VM_PROT_EXECUTE;
return prot;
}
struct i386_iter {
kvm_t *kd;
u_long nptes;
u_long pteindex;
};
static void
_i386_iterator_init(struct i386_iter *it, kvm_t *kd)
{
struct vmstate *vm = kd->vmst;
it->kd = kd;
it->pteindex = 0;
if (vm->hdr.paemode) {
it->nptes = vm->hdr.ptesize / sizeof(i386_pte_pae_t);
} else {
it->nptes = vm->hdr.ptesize / sizeof(i386_pte_t);
}
return;
}
static int
_i386_iterator_next(struct i386_iter *it, u_long *pa, u_long *va, u_long *dva,
vm_prot_t *prot)
{
struct vmstate *vm = it->kd->vmst;
i386_pte_t pte32;
i386_pte_pae_t pte64;
int found = 0;
*dva = 0;
*pa = 0;
*va = 0;
*dva = 0;
*prot = 0;
for (; it->pteindex < it->nptes && found == 0; it->pteindex++) {
if (vm->hdr.paemode) {
pte64 = _i386_pte_pae_get(it->kd, it->pteindex);
if ((pte64 & I386_PG_V) == 0)
continue;
*prot = _i386_entry_to_prot(pte64);
*pa = pte64 & I386_PG_FRAME_PAE;
} else {
pte32 = _i386_pte_get(it->kd, it->pteindex);
if ((pte32 & I386_PG_V) == 0)
continue;
*prot = _i386_entry_to_prot(pte32);
*pa = pte32 & I386_PG_FRAME;
}
*va = vm->hdr.kernbase + (it->pteindex << I386_PAGE_SHIFT);
found = 1;
}
return found;
}
static int
_i386_minidump_walk_pages(kvm_t *kd, kvm_walk_pages_cb_t *cb, void *arg)
{
struct i386_iter it;
u_long dva, pa, va;
vm_prot_t prot;
_i386_iterator_init(&it, kd);
while (_i386_iterator_next(&it, &pa, &va, &dva, &prot)) {
if (!_kvm_visit_cb(kd, cb, arg, pa, va, dva,
prot, I386_PAGE_SIZE, 0)) {
return (0);
}
}
return (1);
}
static struct kvm_arch kvm_i386_minidump = {
.ka_probe = _i386_minidump_probe,
.ka_initvtop = _i386_minidump_initvtop,
.ka_freevtop = _i386_minidump_freevtop,
.ka_kvatop = _i386_minidump_kvatop,
.ka_native = _i386_native,
.ka_walk_pages = _i386_minidump_walk_pages,
};
KVM_ARCH(kvm_i386_minidump);