freebsd-skq/lib/libkvm/kvm_minidump_amd64.c
Andriy Gapon 290e14f881 amd64: introduce minidump version 2
After KVA space was increased to 512GB on amd64 it became impractical
to use PTEs as entries in the minidump map of dumped pages, because size
of that map alone would already be 1GB.
Instead, we now use PDEs as page map entries and employ two stage lookup
in libkvm: virtual address -> PDE -> PTE -> physical address.  PTEs are
now dumped as regular pages.  Fixed page map size now is 2MB.

libkvm keeps support for accessing amd64 minidumps of version 1.
Support for 1GB pages is added.

Many thanks to Alan Cox for his guidance, numerous reviews, suggestions,
enhancments and corrections.

Reviewed by:	alc [kernel part]
MFC after:	15 days
2010-11-11 18:35:28 +00:00

336 lines
8.5 KiB
C

/*-
* 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("$FreeBSD$");
/*
* AMD64 machine dependent routines for kvm and minidumps.
*/
#include <sys/param.h>
#include <sys/user.h>
#include <sys/proc.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <sys/fnv_hash.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <nlist.h>
#include <kvm.h>
#include <vm/vm.h>
#include <vm/vm_param.h>
#include <machine/elf.h>
#include <machine/cpufunc.h>
#include <machine/minidump.h>
#include <limits.h>
#include "kvm_private.h"
struct hpte {
struct hpte *next;
vm_paddr_t pa;
int64_t off;
};
#define HPT_SIZE 1024
/* minidump must be the first item! */
struct vmstate {
int minidump; /* 1 = minidump mode */
struct minidumphdr hdr;
void *hpt_head[HPT_SIZE];
uint64_t *bitmap;
uint64_t *page_map;
};
static void
hpt_insert(kvm_t *kd, vm_paddr_t pa, int64_t off)
{
struct hpte *hpte;
uint32_t fnv = FNV1_32_INIT;
fnv = fnv_32_buf(&pa, sizeof(pa), fnv);
fnv &= (HPT_SIZE - 1);
hpte = malloc(sizeof(*hpte));
hpte->pa = pa;
hpte->off = off;
hpte->next = kd->vmst->hpt_head[fnv];
kd->vmst->hpt_head[fnv] = hpte;
}
static int64_t
hpt_find(kvm_t *kd, vm_paddr_t pa)
{
struct hpte *hpte;
uint32_t fnv = FNV1_32_INIT;
fnv = fnv_32_buf(&pa, sizeof(pa), fnv);
fnv &= (HPT_SIZE - 1);
for (hpte = kd->vmst->hpt_head[fnv]; hpte != NULL; hpte = hpte->next) {
if (pa == hpte->pa)
return (hpte->off);
}
return (-1);
}
static int
inithash(kvm_t *kd, uint64_t *base, int len, off_t off)
{
uint64_t idx;
uint64_t bit, bits;
vm_paddr_t pa;
for (idx = 0; idx < len / sizeof(*base); idx++) {
bits = base[idx];
while (bits) {
bit = bsfq(bits);
bits &= ~(1ul << bit);
pa = (idx * sizeof(*base) * NBBY + bit) * PAGE_SIZE;
hpt_insert(kd, pa, off);
off += PAGE_SIZE;
}
}
return (off);
}
void
_kvm_minidump_freevtop(kvm_t *kd)
{
struct vmstate *vm = kd->vmst;
if (vm->bitmap)
free(vm->bitmap);
if (vm->page_map)
free(vm->page_map);
free(vm);
kd->vmst = NULL;
}
int
_kvm_minidump_initvtop(kvm_t *kd)
{
u_long pa;
struct vmstate *vmst;
off_t off;
vmst = _kvm_malloc(kd, sizeof(*vmst));
if (vmst == 0) {
_kvm_err(kd, kd->program, "cannot allocate vm");
return (-1);
}
kd->vmst = vmst;
vmst->minidump = 1;
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);
}
/*
* NB: amd64 minidump header is binary compatible between version 1
* and version 2; this may not be the case for the future versions.
*/
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);
}
/* Skip header and msgbuf */
off = PAGE_SIZE + round_page(vmst->hdr.msgbufsize);
vmst->bitmap = _kvm_malloc(kd, vmst->hdr.bitmapsize);
if (vmst->bitmap == NULL) {
_kvm_err(kd, kd->program, "cannot allocate %d bytes for bitmap", vmst->hdr.bitmapsize);
return (-1);
}
if (pread(kd->pmfd, vmst->bitmap, vmst->hdr.bitmapsize, off) !=
vmst->hdr.bitmapsize) {
_kvm_err(kd, kd->program, "cannot read %d bytes for page bitmap", vmst->hdr.bitmapsize);
return (-1);
}
off += round_page(vmst->hdr.bitmapsize);
vmst->page_map = _kvm_malloc(kd, vmst->hdr.pmapsize);
if (vmst->page_map == NULL) {
_kvm_err(kd, kd->program, "cannot allocate %d bytes for page_map", vmst->hdr.pmapsize);
return (-1);
}
if (pread(kd->pmfd, vmst->page_map, vmst->hdr.pmapsize, off) !=
vmst->hdr.pmapsize) {
_kvm_err(kd, kd->program, "cannot read %d bytes for page_map", vmst->hdr.pmapsize);
return (-1);
}
off += vmst->hdr.pmapsize;
/* build physical address hash table for sparse pages */
inithash(kd, vmst->bitmap, vmst->hdr.bitmapsize, off);
return (0);
}
static int
_kvm_minidump_vatop_v1(kvm_t *kd, u_long va, off_t *pa)
{
struct vmstate *vm;
u_long offset;
pt_entry_t pte;
u_long pteindex;
int i;
u_long a;
off_t ofs;
vm = kd->vmst;
offset = va & (PAGE_SIZE - 1);
if (va >= vm->hdr.kernbase) {
pteindex = (va - vm->hdr.kernbase) >> PAGE_SHIFT;
pte = vm->page_map[pteindex];
if (((u_long)pte & PG_V) == 0) {
_kvm_err(kd, kd->program, "_kvm_vatop: pte not valid");
goto invalid;
}
a = pte & PG_FRAME;
ofs = hpt_find(kd, a);
if (ofs == -1) {
_kvm_err(kd, kd->program, "_kvm_vatop: physical address 0x%lx not in minidump", a);
goto invalid;
}
*pa = ofs + offset;
return (PAGE_SIZE - offset);
} else if (va >= vm->hdr.dmapbase && va < vm->hdr.dmapend) {
a = (va - vm->hdr.dmapbase) & ~PAGE_MASK;
ofs = hpt_find(kd, a);
if (ofs == -1) {
_kvm_err(kd, kd->program, "_kvm_vatop: direct map address 0x%lx not in minidump", va);
goto invalid;
}
*pa = ofs + offset;
return (PAGE_SIZE - offset);
} else {
_kvm_err(kd, kd->program, "_kvm_vatop: virtual address 0x%lx not minidumped", va);
goto invalid;
}
invalid:
_kvm_err(kd, 0, "invalid address (0x%lx)", va);
return (0);
}
static int
_kvm_minidump_vatop(kvm_t *kd, u_long va, off_t *pa)
{
pt_entry_t pt[NPTEPG];
struct vmstate *vm;
u_long offset;
pd_entry_t pde;
pd_entry_t pte;
u_long pteindex;
u_long pdeindex;
int i;
u_long a;
off_t ofs;
vm = kd->vmst;
offset = va & PAGE_MASK;
if (va >= vm->hdr.kernbase) {
pdeindex = (va - vm->hdr.kernbase) >> PDRSHIFT;
pde = vm->page_map[pdeindex];
if (((u_long)pde & PG_V) == 0) {
_kvm_err(kd, kd->program, "_kvm_vatop: pde not valid");
goto invalid;
}
if ((pde & PG_PS) == 0) {
a = pde & PG_FRAME;
ofs = hpt_find(kd, a);
if (ofs == -1) {
_kvm_err(kd, kd->program, "_kvm_vatop: pt physical address 0x%lx not in minidump", a);
goto invalid;
}
if (pread(kd->pmfd, &pt, PAGE_SIZE, ofs) != PAGE_SIZE) {
_kvm_err(kd, kd->program, "cannot read %d bytes for pt", PAGE_SIZE);
return (-1);
}
pteindex = (va >> PAGE_SHIFT) & ((1ul << NPTEPGSHIFT) - 1);
pte = pt[pteindex];
if (((u_long)pte & PG_V) == 0) {
_kvm_err(kd, kd->program, "_kvm_vatop: pte not valid");
goto invalid;
}
a = pte & PG_FRAME;
} else {
a = pde & PG_PS_FRAME;
a += (va & PDRMASK) ^ offset;
}
ofs = hpt_find(kd, a);
if (ofs == -1) {
_kvm_err(kd, kd->program, "_kvm_vatop: physical address 0x%lx not in minidump", a);
goto invalid;
}
*pa = ofs + offset;
return (PAGE_SIZE - offset);
} else if (va >= vm->hdr.dmapbase && va < vm->hdr.dmapend) {
a = (va - vm->hdr.dmapbase) & ~PAGE_MASK;
ofs = hpt_find(kd, a);
if (ofs == -1) {
_kvm_err(kd, kd->program, "_kvm_vatop: direct map address 0x%lx not in minidump", va);
goto invalid;
}
*pa = ofs + offset;
return (PAGE_SIZE - offset);
} else {
_kvm_err(kd, kd->program, "_kvm_vatop: virtual address 0x%lx not minidumped", va);
goto invalid;
}
invalid:
_kvm_err(kd, 0, "invalid address (0x%lx)", va);
return (0);
}
int
_kvm_minidump_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);
}
if (((struct vmstate *)kd->vmst)->hdr.version == 1)
return (_kvm_minidump_vatop_v1(kd, va, pa));
else
return (_kvm_minidump_vatop(kd, va, pa));
}