syzkaller/executor/test_kvm.cc
Dmitry Vyukov 1c190bb963 executor: fix KVM test
SMM is now supported for real code instead of prot16.
2017-01-27 20:46:09 +01:00

241 lines
8.0 KiB
C++

// Copyright 2017 syzkaller project authors. All rights reserved.
// Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file.
#include "syscalls.h"
#define SYZ_EXECUTOR
#include "common.h"
#include <sys/utsname.h>
extern "C" int test_copyin()
{
unsigned char x[4] = {};
STORE_BY_BITMASK(uint16_t, &x[1], 0x1234, 0, 0);
if (x[0] != 0 || x[1] != 0x34 || x[2] != 0x12 || x[3] != 0) {
printf("bad result of STORE_BY_BITMASK(0, 0): %x %x %x %x\n", x[0], x[1], x[2], x[3]);
return 1;
}
STORE_BY_BITMASK(uint16_t, &x[1], 0x555a, 5, 4);
if (x[0] != 0 || x[1] != 0x54 || x[2] != 0x13 || x[3] != 0) {
printf("bad result of STORE_BY_BITMASK(7, 3): %x %x %x %x\n", x[0], x[1], x[2], x[3]);
return 1;
}
return 0;
}
static unsigned host_kernel_version();
static void dump_cpu_state(int cpufd, char* vm_mem);
static int test_one(int text_type, const char* text, int text_size, int flags, int reason, bool check_rax)
{
printf("=== testing text %d, text size 0x%x, flags 0x%x\n", text_type, text_size, flags);
int kvmfd = open("/dev/kvm", O_RDWR);
if (kvmfd == -1) {
if (errno == ENOENT) {
printf("/dev/kvm is not present\n");
return -1;
}
if (errno == EPERM) {
printf("no permissions to open /dev/kvm\n");
return -1;
}
printf("failed to open /dev/kvm (%d)\n", errno);
return 1;
}
int vmfd = ioctl(kvmfd, KVM_CREATE_VM, 0);
if (vmfd == -1) {
printf("KVM_CREATE_VM failed (%d)\n", errno);
return 1;
}
int cpufd = ioctl(vmfd, KVM_CREATE_VCPU, 0);
if (cpufd == -1) {
printf("KVM_CREATE_VCPU failed (%d)\n", errno);
return 1;
}
int cpu_mem_size = ioctl(kvmfd, KVM_GET_VCPU_MMAP_SIZE, 0);
if (cpu_mem_size <= 0) {
printf("KVM_GET_VCPU_MMAP_SIZE failed (%d)\n", errno);
return 1;
}
struct kvm_run* cpu_mem = (struct kvm_run*)mmap(0, cpu_mem_size, PROT_READ | PROT_WRITE, MAP_SHARED, cpufd, 0);
if (cpu_mem == MAP_FAILED) {
printf("cpu mmap failed (%d)\n", errno);
return 1;
}
int vm_mem_size = 96 << 10;
void* vm_mem = mmap(0, vm_mem_size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
if (vm_mem == MAP_FAILED) {
printf("mmap failed (%d)\n", errno);
return 1;
}
struct kvm_text kvm_text;
kvm_text.typ = text_type;
kvm_text.text = text;
kvm_text.size = text_size;
if (syz_kvm_setup_cpu(vmfd, cpufd, (uintptr_t)vm_mem, (uintptr_t)&kvm_text, 1, flags, 0, 0)) {
printf("syz_kvm_setup_cpu failed (%d)\n", errno);
return 1;
}
if (ioctl(cpufd, KVM_RUN, 0)) {
printf("KVM_RUN failed (%d)\n", errno);
return 1;
}
struct kvm_regs regs;
if (ioctl(cpufd, KVM_GET_REGS, &regs)) {
printf("KVM_GET_REGS failed (%d)\n", errno);
dump_cpu_state(cpufd, (char*)vm_mem);
return 1;
}
if (cpu_mem->exit_reason != reason) {
printf("KVM_RUN exit reason %d, expect %d\n", cpu_mem->exit_reason, reason);
if (cpu_mem->exit_reason == KVM_EXIT_FAIL_ENTRY)
printf("hardware exit reason 0x%llx\n", cpu_mem->fail_entry.hardware_entry_failure_reason);
dump_cpu_state(cpufd, (char*)vm_mem);
return 1;
}
if (check_rax && regs.rax != 0xbadc0de) {
printf("wrong result: rax=0x%llx\n", (long long)regs.rax);
dump_cpu_state(cpufd, (char*)vm_mem);
return 1;
}
munmap(vm_mem, vm_mem_size);
munmap(cpu_mem, cpu_mem_size);
close(cpufd);
close(vmfd);
close(kvmfd);
return 0;
}
extern "C" int test_kvm()
{
int res;
unsigned ver = host_kernel_version();
printf("host kernel version %u\n", ver);
// TODO: test VM mode.
//const char text16_vm[] = "\x48\xc7\xc3\xde\xc0\xad\x0b\x90\x90\x48\xc7\xc0\xef\xcd\xab\x00\xf4";
//if (res = test_one(64, text16_vm, sizeof(text16_vm) - 1, KVM_SETUP_VM, KVM_EXIT_HLT, true))
// return res;
/// TODO: test code executed in interrupt handlers.
//const char text32_div0[] = "\x31\xc0\xf7\xf0";
//if (res = test_one(32, text32_div0, sizeof(text32_div0)-1, 0, KVM_EXIT_HLT, true))
// return res;
const char text8[] = "\x66\xb8\xde\xc0\xad\x0b";
if (res = test_one(8, text8, sizeof(text8) - 1, 0, KVM_EXIT_HLT, true))
return res;
if (res = test_one(8, text8, sizeof(text8) - 1, KVM_SETUP_VIRT86, KVM_EXIT_SHUTDOWN, true))
return res;
if (res = test_one(8, text8, sizeof(text8) - 1, KVM_SETUP_VIRT86 | KVM_SETUP_PAGING, KVM_EXIT_SHUTDOWN, true))
return res;
const char text16[] = "\x66\xb8\xde\xc0\xad\x0b";
if (res = test_one(16, text16, sizeof(text16) - 1, 0, KVM_EXIT_HLT, true))
return res;
if (res = test_one(16, text16, sizeof(text16) - 1, KVM_SETUP_CPL3, KVM_EXIT_SHUTDOWN, true))
return res;
const char text32[] = "\xb8\xde\xc0\xad\x0b";
if (res = test_one(32, text32, sizeof(text32) - 1, 0, KVM_EXIT_HLT, true))
return res;
if (res = test_one(32, text32, sizeof(text32) - 1, KVM_SETUP_PAGING, KVM_EXIT_HLT, true))
return res;
if (res = test_one(32, text32, sizeof(text32) - 1, KVM_SETUP_CPL3, KVM_EXIT_SHUTDOWN, true))
return res;
const char text64[] = "\x90\xb8\xde\xc0\xad\x0b";
if (res = test_one(64, text64, sizeof(text64) - 1, 0, KVM_EXIT_HLT, true))
return res;
if (res = test_one(64, text64, sizeof(text64) - 1, KVM_SETUP_PAGING, KVM_EXIT_HLT, true))
return res;
if (res = test_one(64, text64, sizeof(text64) - 1, KVM_SETUP_CPL3, KVM_EXIT_SHUTDOWN, true))
return res;
const char text64_sysenter[] = "\xb8\xde\xc0\xad\x0b\x0f\x34";
if (res = test_one(64, text64_sysenter, sizeof(text64_sysenter) - 1, KVM_SETUP_CPL3, KVM_EXIT_SHUTDOWN, true))
return res;
// Note: SMM does not work on 3.13 kernels.
if (ver >= 404) {
const char text8_smm[] = "\x66\xb8\xde\xc0\xad\x0b";
if (res = test_one(8, text8_smm, sizeof(text8_smm) - 1, KVM_SETUP_SMM, KVM_EXIT_HLT, true))
return res;
if (res = test_one(8, text8_smm, sizeof(text8_smm) - 1, KVM_SETUP_SMM | KVM_SETUP_PROTECTED, KVM_EXIT_HLT, true))
return res;
//const char text32_smm[] = "\xb8\xde\xc0\xad\x0b";
if (res = test_one(32, text8_smm, sizeof(text8_smm) - 1, KVM_SETUP_SMM, KVM_EXIT_HLT, true))
return res;
// Also ensure that we are actually in SMM.
// If we do MOV to RAX and then RSM, RAX will be restored to host value so RAX check will fail.
// So instead we execute just RSM, if we are in SMM we will get KVM_EXIT_HLT, otherwise KVM_EXIT_INTERNAL_ERROR.
const char text_rsm[] = "\x0f\xaa";
if (res = test_one(8, text_rsm, sizeof(text_rsm) - 1, KVM_SETUP_SMM, KVM_EXIT_HLT, false))
return res;
if (res = test_one(32, text_rsm, sizeof(text_rsm) - 1, KVM_SETUP_SMM, KVM_EXIT_HLT, false))
return res;
}
return 0;
}
static unsigned host_kernel_version()
{
struct utsname name;
if (uname(&name)) {
printf("uname failed (%d)\n", errno);
doexit(1);
}
unsigned major = atoi(name.release);
unsigned minor = 0;
if (strchr(name.release, '.'))
minor = atoi(strchr(name.release, '.') + 1);
return major * 100 + minor;
}
static void dump_seg(const char* name, struct kvm_segment* seg)
{
printf("%s: base=0x%llx limit=0x%x sel=0x%x type=%d p=%d dpl=%d, db=%d s=%d l=%d g=%d\n",
name, seg->base, seg->limit, seg->selector, seg->type, seg->present, seg->dpl, seg->db, seg->s, seg->l, seg->g);
}
static void dump_cpu_state(int cpufd, char* vm_mem)
{
struct kvm_sregs sregs;
if (ioctl(cpufd, KVM_GET_SREGS, &sregs)) {
printf("KVM_GET_SREGS failed (%d)\n", errno);
return;
}
struct kvm_regs regs;
if (ioctl(cpufd, KVM_GET_REGS, &regs)) {
printf("KVM_GET_REGS failed (%d)\n", errno);
return;
}
printf("RIP=0x%llx RAX=0x%llx RDX=0x%llx RCX=0x%llx RBX=0x%llx CF=%d ZF=%d\n",
regs.rip, regs.rax, regs.rdx, regs.rcx, regs.rbx, !!(regs.rflags & (1 << 0)), !!(regs.rflags & (1 << 6)));
printf("CR0=0x%llx CR2=0x%llx CR4=0x%llx EFER=0x%llx\n",
sregs.cr0, sregs.cr2, sregs.cr4, sregs.efer);
dump_seg("CS", &sregs.cs);
dump_seg("SS", &sregs.ss);
dump_seg("DS", &sregs.ds);
if (false) {
printf("memory:\n");
for (int i = 0; i < 0x80; i++)
printf("0x%02x: 0x%02x\n", i, ((unsigned char*)vm_mem)[i]);
}
if (false) {
printf("vmcs:\n");
const int vmcs_size = 0x1000;
for (int i = 0; i < vmcs_size / 8; i += 4) {
printf("0x%04x: 0x%016llx 0x%016llx 0x%016llx 0x%016llx\n", i,
((long long*)vm_mem)[i], ((long long*)vm_mem)[i + 1], ((long long*)vm_mem)[i + 2], ((long long*)vm_mem)[i + 3]);
}
}
}