qemu/dump/win_dump.c
Markus Armbruster 21c06f5780 dump/win_dump: Improve error messages on write error
create_win_dump() and write_run report qemu_write_full() failure to
their callers as

    An IO error has occurred

The errno set by qemu_write_full() is lost.

Improve this to

    win-dump: failed to write header: <description of errno>

and

    win-dump: failed to save memory: <description of errno>

This matches how dump.c reports similar errors.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20240513141703.549874-3-armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
2024-05-27 12:42:12 +02:00

497 lines
14 KiB
C

/*
* Windows crashdump (target specific implementations)
*
* Copyright (c) 2018 Virtuozzo International GmbH
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*
*/
#include "qemu/osdep.h"
#include "sysemu/dump.h"
#include "qapi/error.h"
#include "qemu/error-report.h"
#include "exec/cpu-defs.h"
#include "hw/core/cpu.h"
#include "qemu/win_dump_defs.h"
#include "win_dump.h"
#include "cpu.h"
#if defined(TARGET_X86_64)
bool win_dump_available(Error **errp)
{
return true;
}
static size_t win_dump_ptr_size(bool x64)
{
return x64 ? sizeof(uint64_t) : sizeof(uint32_t);
}
#define _WIN_DUMP_FIELD(f) (x64 ? h->x64.f : h->x32.f)
#define WIN_DUMP_FIELD(field) _WIN_DUMP_FIELD(field)
#define _WIN_DUMP_FIELD_PTR(f) (x64 ? (void *)&h->x64.f : (void *)&h->x32.f)
#define WIN_DUMP_FIELD_PTR(field) _WIN_DUMP_FIELD_PTR(field)
#define _WIN_DUMP_FIELD_SIZE(f) (x64 ? sizeof(h->x64.f) : sizeof(h->x32.f))
#define WIN_DUMP_FIELD_SIZE(field) _WIN_DUMP_FIELD_SIZE(field)
static size_t win_dump_ctx_size(bool x64)
{
return x64 ? sizeof(WinContext64) : sizeof(WinContext32);
}
static size_t write_run(uint64_t base_page, uint64_t page_count,
int fd, Error **errp)
{
void *buf;
uint64_t addr = base_page << TARGET_PAGE_BITS;
uint64_t size = page_count << TARGET_PAGE_BITS;
uint64_t len, l;
int eno;
size_t total = 0;
while (size) {
len = size;
buf = cpu_physical_memory_map(addr, &len, false);
if (!buf) {
error_setg(errp, "win-dump: failed to map physical range"
" 0x%016" PRIx64 "-0x%016" PRIx64, addr, addr + size - 1);
return 0;
}
l = qemu_write_full(fd, buf, len);
eno = errno;
cpu_physical_memory_unmap(buf, addr, false, len);
if (l != len) {
error_setg_errno(errp, eno, "win-dump: failed to save memory");
return 0;
}
addr += l;
size -= l;
total += l;
}
return total;
}
static void write_runs(DumpState *s, WinDumpHeader *h, bool x64, Error **errp)
{
uint64_t BasePage, PageCount;
Error *local_err = NULL;
int i;
for (i = 0; i < WIN_DUMP_FIELD(PhysicalMemoryBlock.NumberOfRuns); i++) {
BasePage = WIN_DUMP_FIELD(PhysicalMemoryBlock.Run[i].BasePage);
PageCount = WIN_DUMP_FIELD(PhysicalMemoryBlock.Run[i].PageCount);
s->written_size += write_run(BasePage, PageCount, s->fd, &local_err);
if (local_err) {
error_propagate(errp, local_err);
return;
}
}
}
static int cpu_read_ptr(bool x64, CPUState *cpu, uint64_t addr, uint64_t *ptr)
{
int ret;
uint32_t ptr32;
uint64_t ptr64;
ret = cpu_memory_rw_debug(cpu, addr, x64 ? (void *)&ptr64 : (void *)&ptr32,
win_dump_ptr_size(x64), 0);
*ptr = x64 ? ptr64 : ptr32;
return ret;
}
static void patch_mm_pfn_database(WinDumpHeader *h, bool x64, Error **errp)
{
if (cpu_memory_rw_debug(first_cpu,
WIN_DUMP_FIELD(KdDebuggerDataBlock) + KDBG_MM_PFN_DATABASE_OFFSET,
WIN_DUMP_FIELD_PTR(PfnDatabase),
WIN_DUMP_FIELD_SIZE(PfnDatabase), 0)) {
error_setg(errp, "win-dump: failed to read MmPfnDatabase");
return;
}
}
static void patch_bugcheck_data(WinDumpHeader *h, bool x64, Error **errp)
{
uint64_t KiBugcheckData;
if (cpu_read_ptr(x64, first_cpu,
WIN_DUMP_FIELD(KdDebuggerDataBlock) + KDBG_KI_BUGCHECK_DATA_OFFSET,
&KiBugcheckData)) {
error_setg(errp, "win-dump: failed to read KiBugcheckData");
return;
}
if (cpu_memory_rw_debug(first_cpu, KiBugcheckData,
WIN_DUMP_FIELD(BugcheckData),
WIN_DUMP_FIELD_SIZE(BugcheckData), 0)) {
error_setg(errp, "win-dump: failed to read bugcheck data");
return;
}
/*
* If BugcheckCode wasn't saved, we consider guest OS as alive.
*/
if (!WIN_DUMP_FIELD(BugcheckCode)) {
*(uint32_t *)WIN_DUMP_FIELD_PTR(BugcheckCode) = LIVE_SYSTEM_DUMP;
}
}
/*
* This routine tries to correct mistakes in crashdump header.
*/
static void patch_header(WinDumpHeader *h, bool x64)
{
Error *local_err = NULL;
if (x64) {
h->x64.RequiredDumpSpace = sizeof(WinDumpHeader64) +
(h->x64.PhysicalMemoryBlock.NumberOfPages << TARGET_PAGE_BITS);
h->x64.PhysicalMemoryBlock.unused = 0;
h->x64.unused1 = 0;
} else {
h->x32.RequiredDumpSpace = sizeof(WinDumpHeader32) +
(h->x32.PhysicalMemoryBlock.NumberOfPages << TARGET_PAGE_BITS);
}
patch_mm_pfn_database(h, x64, &local_err);
if (local_err) {
warn_report_err(local_err);
local_err = NULL;
}
patch_bugcheck_data(h, x64, &local_err);
if (local_err) {
warn_report_err(local_err);
}
}
static bool check_header(WinDumpHeader *h, bool *x64, Error **errp)
{
const char Signature[] = "PAGE";
if (memcmp(h->Signature, Signature, sizeof(h->Signature))) {
error_setg(errp, "win-dump: invalid header, expected '%.4s',"
" got '%.4s'", Signature, h->Signature);
return false;
}
if (!memcmp(h->ValidDump, "DUMP", sizeof(h->ValidDump))) {
*x64 = false;
} else if (!memcmp(h->ValidDump, "DU64", sizeof(h->ValidDump))) {
*x64 = true;
} else {
error_setg(errp, "win-dump: invalid header, expected 'DUMP' or 'DU64',"
" got '%.4s'", h->ValidDump);
return false;
}
return true;
}
static void check_kdbg(WinDumpHeader *h, bool x64, Error **errp)
{
const char OwnerTag[] = "KDBG";
char read_OwnerTag[4];
uint64_t KdDebuggerDataBlock = WIN_DUMP_FIELD(KdDebuggerDataBlock);
bool try_fallback = true;
try_again:
if (cpu_memory_rw_debug(first_cpu,
KdDebuggerDataBlock + KDBG_OWNER_TAG_OFFSET,
(uint8_t *)&read_OwnerTag, sizeof(read_OwnerTag), 0)) {
error_setg(errp, "win-dump: failed to read OwnerTag");
return;
}
if (memcmp(read_OwnerTag, OwnerTag, sizeof(read_OwnerTag))) {
if (try_fallback) {
/*
* If attempt to use original KDBG failed
* (most likely because of its encryption),
* we try to use KDBG obtained by guest driver.
*/
KdDebuggerDataBlock = WIN_DUMP_FIELD(BugcheckParameter1);
try_fallback = false;
goto try_again;
} else {
error_setg(errp, "win-dump: invalid KDBG OwnerTag,"
" expected '%.4s', got '%.4s'",
OwnerTag, read_OwnerTag);
return;
}
}
if (x64) {
h->x64.KdDebuggerDataBlock = KdDebuggerDataBlock;
} else {
h->x32.KdDebuggerDataBlock = KdDebuggerDataBlock;
}
}
struct saved_context {
WinContext ctx;
uint64_t addr;
};
static void patch_and_save_context(WinDumpHeader *h, bool x64,
struct saved_context *saved_ctx,
Error **errp)
{
uint64_t KdDebuggerDataBlock = WIN_DUMP_FIELD(KdDebuggerDataBlock);
uint64_t KiProcessorBlock;
uint16_t OffsetPrcbContext;
CPUState *cpu;
int i = 0;
if (cpu_read_ptr(x64, first_cpu,
KdDebuggerDataBlock + KDBG_KI_PROCESSOR_BLOCK_OFFSET,
&KiProcessorBlock)) {
error_setg(errp, "win-dump: failed to read KiProcessorBlock");
return;
}
if (cpu_memory_rw_debug(first_cpu,
KdDebuggerDataBlock + KDBG_OFFSET_PRCB_CONTEXT_OFFSET,
(uint8_t *)&OffsetPrcbContext, sizeof(OffsetPrcbContext), 0)) {
error_setg(errp, "win-dump: failed to read OffsetPrcbContext");
return;
}
CPU_FOREACH(cpu) {
X86CPU *x86_cpu = X86_CPU(cpu);
CPUX86State *env = &x86_cpu->env;
uint64_t Prcb;
uint64_t Context;
WinContext ctx;
if (i >= WIN_DUMP_FIELD(NumberProcessors)) {
warn_report("win-dump: number of QEMU CPUs is bigger than"
" NumberProcessors (%u) in guest Windows",
WIN_DUMP_FIELD(NumberProcessors));
return;
}
if (cpu_read_ptr(x64, first_cpu,
KiProcessorBlock + i * win_dump_ptr_size(x64),
&Prcb)) {
error_setg(errp, "win-dump: failed to read"
" CPU #%d PRCB location", i);
return;
}
if (cpu_read_ptr(x64, first_cpu,
Prcb + OffsetPrcbContext,
&Context)) {
error_setg(errp, "win-dump: failed to read"
" CPU #%d ContextFrame location", i);
return;
}
saved_ctx[i].addr = Context;
if (x64) {
ctx.x64 = (WinContext64){
.ContextFlags = WIN_CTX64_ALL,
.MxCsr = env->mxcsr,
.SegEs = env->segs[0].selector,
.SegCs = env->segs[1].selector,
.SegSs = env->segs[2].selector,
.SegDs = env->segs[3].selector,
.SegFs = env->segs[4].selector,
.SegGs = env->segs[5].selector,
.EFlags = cpu_compute_eflags(env),
.Dr0 = env->dr[0],
.Dr1 = env->dr[1],
.Dr2 = env->dr[2],
.Dr3 = env->dr[3],
.Dr6 = env->dr[6],
.Dr7 = env->dr[7],
.Rax = env->regs[R_EAX],
.Rbx = env->regs[R_EBX],
.Rcx = env->regs[R_ECX],
.Rdx = env->regs[R_EDX],
.Rsp = env->regs[R_ESP],
.Rbp = env->regs[R_EBP],
.Rsi = env->regs[R_ESI],
.Rdi = env->regs[R_EDI],
.R8 = env->regs[8],
.R9 = env->regs[9],
.R10 = env->regs[10],
.R11 = env->regs[11],
.R12 = env->regs[12],
.R13 = env->regs[13],
.R14 = env->regs[14],
.R15 = env->regs[15],
.Rip = env->eip,
.FltSave = {
.MxCsr = env->mxcsr,
},
};
} else {
ctx.x32 = (WinContext32){
.ContextFlags = WIN_CTX32_FULL | WIN_CTX_DBG,
.SegEs = env->segs[0].selector,
.SegCs = env->segs[1].selector,
.SegSs = env->segs[2].selector,
.SegDs = env->segs[3].selector,
.SegFs = env->segs[4].selector,
.SegGs = env->segs[5].selector,
.EFlags = cpu_compute_eflags(env),
.Dr0 = env->dr[0],
.Dr1 = env->dr[1],
.Dr2 = env->dr[2],
.Dr3 = env->dr[3],
.Dr6 = env->dr[6],
.Dr7 = env->dr[7],
.Eax = env->regs[R_EAX],
.Ebx = env->regs[R_EBX],
.Ecx = env->regs[R_ECX],
.Edx = env->regs[R_EDX],
.Esp = env->regs[R_ESP],
.Ebp = env->regs[R_EBP],
.Esi = env->regs[R_ESI],
.Edi = env->regs[R_EDI],
.Eip = env->eip,
};
}
if (cpu_memory_rw_debug(first_cpu, Context,
&saved_ctx[i].ctx, win_dump_ctx_size(x64), 0)) {
error_setg(errp, "win-dump: failed to save CPU #%d context", i);
return;
}
if (cpu_memory_rw_debug(first_cpu, Context,
&ctx, win_dump_ctx_size(x64), 1)) {
error_setg(errp, "win-dump: failed to write CPU #%d context", i);
return;
}
i++;
}
}
static void restore_context(WinDumpHeader *h, bool x64,
struct saved_context *saved_ctx)
{
int i;
for (i = 0; i < WIN_DUMP_FIELD(NumberProcessors); i++) {
if (cpu_memory_rw_debug(first_cpu, saved_ctx[i].addr,
&saved_ctx[i].ctx, win_dump_ctx_size(x64), 1)) {
warn_report("win-dump: failed to restore CPU #%d context", i);
}
}
}
void create_win_dump(DumpState *s, Error **errp)
{
WinDumpHeader *h = (void *)(s->guest_note + VMCOREINFO_ELF_NOTE_HDR_SIZE);
X86CPU *first_x86_cpu = X86_CPU(first_cpu);
uint64_t saved_cr3 = first_x86_cpu->env.cr[3];
struct saved_context *saved_ctx = NULL;
Error *local_err = NULL;
bool x64 = true;
size_t hdr_size;
if (s->guest_note_size != VMCOREINFO_WIN_DUMP_NOTE_SIZE32 &&
s->guest_note_size != VMCOREINFO_WIN_DUMP_NOTE_SIZE64) {
error_setg(errp, "win-dump: invalid vmcoreinfo note size");
return;
}
if (!check_header(h, &x64, &local_err)) {
error_propagate(errp, local_err);
return;
}
hdr_size = x64 ? sizeof(WinDumpHeader64) : sizeof(WinDumpHeader32);
/*
* Further access to kernel structures by virtual addresses
* should be made from system context.
*/
first_x86_cpu->env.cr[3] = WIN_DUMP_FIELD(DirectoryTableBase);
check_kdbg(h, x64, &local_err);
if (local_err) {
error_propagate(errp, local_err);
goto out_cr3;
}
patch_header(h, x64);
saved_ctx = g_new(struct saved_context, WIN_DUMP_FIELD(NumberProcessors));
/*
* Always patch context because there is no way
* to determine if the system-saved context is valid
*/
patch_and_save_context(h, x64, saved_ctx, &local_err);
if (local_err) {
error_propagate(errp, local_err);
goto out_free;
}
s->total_size = WIN_DUMP_FIELD(RequiredDumpSpace);
s->written_size = qemu_write_full(s->fd, h, hdr_size);
if (s->written_size != hdr_size) {
error_setg_errno(errp, errno, "win-dump: failed to write header");
goto out_restore;
}
write_runs(s, h, x64, &local_err);
if (local_err) {
error_propagate(errp, local_err);
goto out_restore;
}
out_restore:
restore_context(h, x64, saved_ctx);
out_free:
g_free(saved_ctx);
out_cr3:
first_x86_cpu->env.cr[3] = saved_cr3;
return;
}
#else /* !TARGET_X86_64 */
bool win_dump_available(Error **errp)
{
error_setg(errp, "Windows dump is only available for x86-64");
return false;
}
void create_win_dump(DumpState *s, Error **errp)
{
win_dump_available(errp);
}
#endif