dump/win_dump.c - qemu - Git at Google

 /*
  * Windows crashdump
  *
  * 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 "qemu-common.h"
 #include "qemu/cutils.h"
 #include "elf.h"
 #include "cpu.h"
 #include "exec/hwaddr.h"
 #include "monitor/monitor.h"
 #include "sysemu/kvm.h"
 #include "sysemu/dump.h"
 #include "sysemu/memory_mapping.h"
 #include "sysemu/cpus.h"
 #include "qapi/error.h"
 #include "qapi/qmp/qerror.h"
 #include "qemu/error-report.h"
 #include "hw/misc/vmcoreinfo.h"
 #include "win_dump.h"

 static size_t write_run(WinDumpPhyMemRun64 *run, int fd, Error **errp)
 {
     void *buf;
     uint64_t addr = run->BasePage << TARGET_PAGE_BITS;
     uint64_t size = run->PageCount << TARGET_PAGE_BITS;
     uint64_t len, l;
     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);
         cpu_physical_memory_unmap(buf, addr, false, len);
         if (l != len) {
             error_setg(errp, QERR_IO_ERROR);
             return 0;
         }

         addr += l;
         size -= l;
         total += l;
     }

     return total;
 }

 static void write_runs(DumpState *s, WinDumpHeader64 *h, Error **errp)
 {
     WinDumpPhyMemDesc64 *desc = &h->PhysicalMemoryBlock;
     WinDumpPhyMemRun64 *run = desc->Run;
     Error *local_err = NULL;
     int i;

     for (i = 0; i < desc->NumberOfRuns; i++) {
         s->written_size += write_run(run + i, s->fd, &local_err);
         if (local_err) {
             error_propagate(errp, local_err);
             return;
         }
     }
 }

 static void patch_mm_pfn_database(WinDumpHeader64 *h, Error **errp)
 {
     if (cpu_memory_rw_debug(first_cpu,
             h->KdDebuggerDataBlock + KDBG_MM_PFN_DATABASE_OFFSET64,
             (uint8_t *)&h->PfnDatabase, sizeof(h->PfnDatabase), 0)) {
         error_setg(errp, "win-dump: failed to read MmPfnDatabase");
         return;
     }
 }

 static void patch_bugcheck_data(WinDumpHeader64 *h, Error **errp)
 {
     uint64_t KiBugcheckData;

     if (cpu_memory_rw_debug(first_cpu,
             h->KdDebuggerDataBlock + KDBG_KI_BUGCHECK_DATA_OFFSET64,
             (uint8_t *)&KiBugcheckData, sizeof(KiBugcheckData), 0)) {
         error_setg(errp, "win-dump: failed to read KiBugcheckData");
         return;
     }

     if (cpu_memory_rw_debug(first_cpu,
             KiBugcheckData,
             h->BugcheckData, sizeof(h->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 (!h->BugcheckCode) {
         h->BugcheckCode = LIVE_SYSTEM_DUMP;
     }
 }

 /*
  * This routine tries to correct mistakes in crashdump header.
  */
 static void patch_header(WinDumpHeader64 *h)
 {
     Error *local_err = NULL;

     h->RequiredDumpSpace = sizeof(WinDumpHeader64) +
             (h->PhysicalMemoryBlock.NumberOfPages << TARGET_PAGE_BITS);
     h->PhysicalMemoryBlock.unused = 0;
     h->unused1 = 0;

     patch_mm_pfn_database(h, &local_err);
     if (local_err) {
         warn_report_err(local_err);
         local_err = NULL;
     }
     patch_bugcheck_data(h, &local_err);
     if (local_err) {
         warn_report_err(local_err);
     }
 }

 static void check_header(WinDumpHeader64 *h, Error **errp)
 {
     const char Signature[] = "PAGE";
     const char ValidDump[] = "DU64";

     if (memcmp(h->Signature, Signature, sizeof(h->Signature))) {
         error_setg(errp, "win-dump: invalid header, expected '%.4s',"
                          " got '%.4s'", Signature, h->Signature);
         return;
     }

     if (memcmp(h->ValidDump, ValidDump, sizeof(h->ValidDump))) {
         error_setg(errp, "win-dump: invalid header, expected '%.4s',"
                          " got '%.4s'", ValidDump, h->ValidDump);
         return;
     }
 }

 static void check_kdbg(WinDumpHeader64 *h, Error **errp)
 {
     const char OwnerTag[] = "KDBG";
     char read_OwnerTag[4];
     uint64_t KdDebuggerDataBlock = h->KdDebuggerDataBlock;
     bool try_fallback = true;

 try_again:
     if (cpu_memory_rw_debug(first_cpu,
             KdDebuggerDataBlock + KDBG_OWNER_TAG_OFFSET64,
             (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 = h->BugcheckParameter1;
             try_fallback = false;
             goto try_again;
         } else {
             error_setg(errp, "win-dump: invalid KDBG OwnerTag,"
                              " expected '%.4s', got '%.4s'",
                              OwnerTag, read_OwnerTag);
             return;
         }
     }

     h->KdDebuggerDataBlock = KdDebuggerDataBlock;
 }

 struct saved_context {
     WinContext ctx;
     uint64_t addr;
 };

 static void patch_and_save_context(WinDumpHeader64 *h,
                                    struct saved_context *saved_ctx,
                                    Error **errp)
 {
     uint64_t KiProcessorBlock;
     uint16_t OffsetPrcbContext;
     CPUState *cpu;
     int i = 0;

     if (cpu_memory_rw_debug(first_cpu,
             h->KdDebuggerDataBlock + KDBG_KI_PROCESSOR_BLOCK_OFFSET64,
             (uint8_t *)&KiProcessorBlock, sizeof(KiProcessorBlock), 0)) {
         error_setg(errp, "win-dump: failed to read KiProcessorBlock");
         return;
     }

     if (cpu_memory_rw_debug(first_cpu,
             h->KdDebuggerDataBlock + KDBG_OFFSET_PRCB_CONTEXT_OFFSET64,
             (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 (cpu_memory_rw_debug(first_cpu,
                 KiProcessorBlock + i * sizeof(uint64_t),
                 (uint8_t *)&Prcb, sizeof(Prcb), 0)) {
             error_setg(errp, "win-dump: failed to read"
                              " CPU #%d PRCB location", i);
             return;
         }

         if (cpu_memory_rw_debug(first_cpu,
                 Prcb + OffsetPrcbContext,
                 (uint8_t *)&Context, sizeof(Context), 0)) {
             error_setg(errp, "win-dump: failed to read"
                              " CPU #%d ContextFrame location", i);
             return;
         }

         saved_ctx[i].addr = Context;

         ctx = (WinContext){
             .ContextFlags = WIN_CTX_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,
             },
         };

         if (cpu_memory_rw_debug(first_cpu, Context,
                 (uint8_t *)&saved_ctx[i].ctx, sizeof(WinContext), 0)) {
             error_setg(errp, "win-dump: failed to save CPU #%d context", i);
             return;
         }

         if (cpu_memory_rw_debug(first_cpu, Context,
                 (uint8_t *)&ctx, sizeof(WinContext), 1)) {
             error_setg(errp, "win-dump: failed to write CPU #%d context", i);
             return;
         }

         i++;
     }
 }

 static void restore_context(WinDumpHeader64 *h,
                             struct saved_context *saved_ctx)
 {
     int i;

     for (i = 0; i < h->NumberProcessors; i++) {
         if (cpu_memory_rw_debug(first_cpu, saved_ctx[i].addr,
                 (uint8_t *)&saved_ctx[i].ctx, sizeof(WinContext), 1)) {
             warn_report("win-dump: failed to restore CPU #%d context", i);
         }
     }
 }

 void create_win_dump(DumpState *s, Error **errp)
 {
     WinDumpHeader64 *h = (WinDumpHeader64 *)(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;

     if (s->guest_note_size != sizeof(WinDumpHeader64) +
             VMCOREINFO_ELF_NOTE_HDR_SIZE) {
         error_setg(errp, "win-dump: invalid vmcoreinfo note size");
         return;
     }

     check_header(h, &local_err);
     if (local_err) {
         error_propagate(errp, local_err);
         return;
     }

     /*
      * Further access to kernel structures by virtual addresses
      * should be made from system context.
      */

     first_x86_cpu->env.cr[3] = h->DirectoryTableBase;

     check_kdbg(h, &local_err);
     if (local_err) {
         error_propagate(errp, local_err);
         goto out_cr3;
     }

     patch_header(h);

     saved_ctx = g_new(struct saved_context, h->NumberProcessors);

     /*
      * Always patch context because there is no way
      * to determine if the system-saved context is valid
      */

     patch_and_save_context(h, saved_ctx, &local_err);
     if (local_err) {
         error_propagate(errp, local_err);
         goto out_free;
     }

     s->total_size = h->RequiredDumpSpace;

     s->written_size = qemu_write_full(s->fd, h, sizeof(*h));
     if (s->written_size != sizeof(*h)) {
         error_setg(errp, QERR_IO_ERROR);
         goto out_restore;
     }

     write_runs(s, h, &local_err);
     if (local_err) {
         error_propagate(errp, local_err);
         goto out_restore;
     }

 out_restore:
     restore_context(h, saved_ctx);
 out_free:
     g_free(saved_ctx);
 out_cr3:
     first_x86_cpu->env.cr[3] = saved_cr3;

     return;
 }
	/*
	* Windows crashdump
	*
	* 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 "qemu-common.h"
	#include "qemu/cutils.h"
	#include "elf.h"
	#include "cpu.h"
	#include "exec/hwaddr.h"
	#include "monitor/monitor.h"
	#include "sysemu/kvm.h"
	#include "sysemu/dump.h"
	#include "sysemu/memory_mapping.h"
	#include "sysemu/cpus.h"
	#include "qapi/error.h"
	#include "qapi/qmp/qerror.h"
	#include "qemu/error-report.h"
	#include "hw/misc/vmcoreinfo.h"
	#include "win_dump.h"

	static size_t write_run(WinDumpPhyMemRun64 run, int fd, Error *errp)
	{
	void *buf;
	uint64_t addr = run->BasePage << TARGET_PAGE_BITS;
	uint64_t size = run->PageCount << TARGET_PAGE_BITS;
	uint64_t len, l;
	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);
	cpu_physical_memory_unmap(buf, addr, false, len);
	if (l != len) {
	error_setg(errp, QERR_IO_ERROR);
	return 0;
	}

	addr += l;
	size -= l;
	total += l;
	}

	return total;
	}

	static void write_runs(DumpState s, WinDumpHeader64 h, Error **errp)
	{
	WinDumpPhyMemDesc64 *desc = &h->PhysicalMemoryBlock;
	WinDumpPhyMemRun64 *run = desc->Run;
	Error *local_err = NULL;
	int i;

	for (i = 0; i < desc->NumberOfRuns; i++) {
	s->written_size += write_run(run + i, s->fd, &local_err);
	if (local_err) {
	error_propagate(errp, local_err);
	return;
	}
	}
	}

	static void patch_mm_pfn_database(WinDumpHeader64 h, Error *errp)
	{
	if (cpu_memory_rw_debug(first_cpu,
	h->KdDebuggerDataBlock + KDBG_MM_PFN_DATABASE_OFFSET64,
	(uint8_t *)&h->PfnDatabase, sizeof(h->PfnDatabase), 0)) {
	error_setg(errp, "win-dump: failed to read MmPfnDatabase");
	return;
	}
	}

	static void patch_bugcheck_data(WinDumpHeader64 h, Error *errp)
	{
	uint64_t KiBugcheckData;

	if (cpu_memory_rw_debug(first_cpu,
	h->KdDebuggerDataBlock + KDBG_KI_BUGCHECK_DATA_OFFSET64,
	(uint8_t *)&KiBugcheckData, sizeof(KiBugcheckData), 0)) {
	error_setg(errp, "win-dump: failed to read KiBugcheckData");
	return;
	}

	if (cpu_memory_rw_debug(first_cpu,
	KiBugcheckData,
	h->BugcheckData, sizeof(h->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 (!h->BugcheckCode) {
	h->BugcheckCode = LIVE_SYSTEM_DUMP;
	}
	}

	/*
	* This routine tries to correct mistakes in crashdump header.
	*/
	static void patch_header(WinDumpHeader64 *h)
	{
	Error *local_err = NULL;

	h->RequiredDumpSpace = sizeof(WinDumpHeader64) +
	(h->PhysicalMemoryBlock.NumberOfPages << TARGET_PAGE_BITS);
	h->PhysicalMemoryBlock.unused = 0;
	h->unused1 = 0;

	patch_mm_pfn_database(h, &local_err);
	if (local_err) {
	warn_report_err(local_err);
	local_err = NULL;
	}
	patch_bugcheck_data(h, &local_err);
	if (local_err) {
	warn_report_err(local_err);
	}
	}

	static void check_header(WinDumpHeader64 h, Error *errp)
	{
	const char Signature[] = "PAGE";
	const char ValidDump[] = "DU64";

	if (memcmp(h->Signature, Signature, sizeof(h->Signature))) {
	error_setg(errp, "win-dump: invalid header, expected '%.4s',"
	" got '%.4s'", Signature, h->Signature);
	return;
	}

	if (memcmp(h->ValidDump, ValidDump, sizeof(h->ValidDump))) {
	error_setg(errp, "win-dump: invalid header, expected '%.4s',"
	" got '%.4s'", ValidDump, h->ValidDump);
	return;
	}
	}

	static void check_kdbg(WinDumpHeader64 h, Error *errp)
	{
	const char OwnerTag[] = "KDBG";
	char read_OwnerTag[4];
	uint64_t KdDebuggerDataBlock = h->KdDebuggerDataBlock;
	bool try_fallback = true;

	try_again:
	if (cpu_memory_rw_debug(first_cpu,
	KdDebuggerDataBlock + KDBG_OWNER_TAG_OFFSET64,
	(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 = h->BugcheckParameter1;
	try_fallback = false;
	goto try_again;
	} else {
	error_setg(errp, "win-dump: invalid KDBG OwnerTag,"
	" expected '%.4s', got '%.4s'",
	OwnerTag, read_OwnerTag);
	return;
	}
	}

	h->KdDebuggerDataBlock = KdDebuggerDataBlock;
	}

	struct saved_context {
	WinContext ctx;
	uint64_t addr;
	};

	static void patch_and_save_context(WinDumpHeader64 *h,
	struct saved_context *saved_ctx,
	Error **errp)
	{
	uint64_t KiProcessorBlock;
	uint16_t OffsetPrcbContext;
	CPUState *cpu;
	int i = 0;

	if (cpu_memory_rw_debug(first_cpu,
	h->KdDebuggerDataBlock + KDBG_KI_PROCESSOR_BLOCK_OFFSET64,
	(uint8_t *)&KiProcessorBlock, sizeof(KiProcessorBlock), 0)) {
	error_setg(errp, "win-dump: failed to read KiProcessorBlock");
	return;
	}

	if (cpu_memory_rw_debug(first_cpu,
	h->KdDebuggerDataBlock + KDBG_OFFSET_PRCB_CONTEXT_OFFSET64,
	(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 (cpu_memory_rw_debug(first_cpu,
	KiProcessorBlock + i * sizeof(uint64_t),
	(uint8_t *)&Prcb, sizeof(Prcb), 0)) {
	error_setg(errp, "win-dump: failed to read"
	" CPU #%d PRCB location", i);
	return;
	}

	if (cpu_memory_rw_debug(first_cpu,
	Prcb + OffsetPrcbContext,
	(uint8_t *)&Context, sizeof(Context), 0)) {
	error_setg(errp, "win-dump: failed to read"
	" CPU #%d ContextFrame location", i);
	return;
	}

	saved_ctx[i].addr = Context;

	ctx = (WinContext){
	.ContextFlags = WIN_CTX_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,
	},
	};

	if (cpu_memory_rw_debug(first_cpu, Context,
	(uint8_t *)&saved_ctx[i].ctx, sizeof(WinContext), 0)) {
	error_setg(errp, "win-dump: failed to save CPU #%d context", i);
	return;
	}

	if (cpu_memory_rw_debug(first_cpu, Context,
	(uint8_t *)&ctx, sizeof(WinContext), 1)) {
	error_setg(errp, "win-dump: failed to write CPU #%d context", i);
	return;
	}

	i++;
	}
	}

	static void restore_context(WinDumpHeader64 *h,
	struct saved_context *saved_ctx)
	{
	int i;

	for (i = 0; i < h->NumberProcessors; i++) {
	if (cpu_memory_rw_debug(first_cpu, saved_ctx[i].addr,
	(uint8_t *)&saved_ctx[i].ctx, sizeof(WinContext), 1)) {
	warn_report("win-dump: failed to restore CPU #%d context", i);
	}
	}
	}

	void create_win_dump(DumpState s, Error *errp)
	{
	WinDumpHeader64 h = (WinDumpHeader64 )(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;

	if (s->guest_note_size != sizeof(WinDumpHeader64) +
	VMCOREINFO_ELF_NOTE_HDR_SIZE) {
	error_setg(errp, "win-dump: invalid vmcoreinfo note size");
	return;
	}

	check_header(h, &local_err);
	if (local_err) {
	error_propagate(errp, local_err);
	return;
	}

	/*
	* Further access to kernel structures by virtual addresses
	* should be made from system context.
	*/

	first_x86_cpu->env.cr[3] = h->DirectoryTableBase;

	check_kdbg(h, &local_err);
	if (local_err) {
	error_propagate(errp, local_err);
	goto out_cr3;
	}

	patch_header(h);

	saved_ctx = g_new(struct saved_context, h->NumberProcessors);

	/*
	* Always patch context because there is no way
	* to determine if the system-saved context is valid
	*/

	patch_and_save_context(h, saved_ctx, &local_err);
	if (local_err) {
	error_propagate(errp, local_err);
	goto out_free;
	}

	s->total_size = h->RequiredDumpSpace;

	s->written_size = qemu_write_full(s->fd, h, sizeof(*h));
	if (s->written_size != sizeof(*h)) {
	error_setg(errp, QERR_IO_ERROR);
	goto out_restore;
	}

	write_runs(s, h, &local_err);
	if (local_err) {
	error_propagate(errp, local_err);
	goto out_restore;
	}

	out_restore:
	restore_context(h, saved_ctx);
	out_free:
	g_free(saved_ctx);
	out_cr3:
	first_x86_cpu->env.cr[3] = saved_cr3;

	return;
	}