unicorn/samples/sample_mmu.c

444 lines
12 KiB
C

#include <unicorn/unicorn.h>
#include <stdio.h>
/*
* mov rax, 57
* syscall
* test rax, rax
* jz child
* xor rax, rax
* mov rax, 60
* mov [0x4000], rax
* syscall
*
* child:
* xor rcx, rcx
* mov rcx, 42
* mov [0x4000], rcx
* mov rax, 60
* syscall
*/
char code[] = "\xB8\x39\x00\x00\x00\x0F\x05\x48\x85\xC0\x74\x0F\xB8\x3C\x00\x00"
"\x00\x48\x89\x04\x25\x00\x40\x00\x00\x0F\x05\xB9\x2A\x00\x00\x00"
"\x48\x89\x0C\x25\x00\x40\x00\x00\xB8\x3C\x00\x00\x00\x0F\x05";
static void mmu_write_callback(uc_engine *uc, uc_mem_type type,
uint64_t address, int size, int64_t value,
void *user_data)
{
printf("write at 0x%lx: 0x%lx\n", address, value);
}
static void x86_mmu_prepare_tlb(uc_engine *uc, uint64_t vaddr,
uint64_t tlb_base)
{
uc_err err;
uint64_t cr0;
uint64_t cr4;
uc_x86_msr msr = {.rid = 0xC0000080, .value = 0};
uint64_t pml4o = ((vaddr & 0x00ff8000000000) >> 39) * 8;
uint64_t pdpo = ((vaddr & 0x00007fc0000000) >> 30) * 8;
uint64_t pdo = ((vaddr & 0x0000003fe00000) >> 21) * 8;
uint64_t pml4e = (tlb_base + 0x1000) | 1 | (1 << 2);
uint64_t pdpe = (tlb_base + 0x2000) | 1 | (1 << 2);
uint64_t pde = (tlb_base + 0x3000) | 1 | (1 << 2);
err = uc_mem_write(uc, tlb_base + pml4o, &pml4e, sizeof(pml4o));
if (err) {
printf("failed to write pml4e\n");
exit(1);
}
err = uc_mem_write(uc, tlb_base + 0x1000 + pdpo, &pdpe, sizeof(pdpe));
if (err) {
printf("failed to write pml4e\n");
exit(1);
}
err = uc_mem_write(uc, tlb_base + 0x2000 + pdo, &pde, sizeof(pde));
if (err) {
printf("failed to write pde\n");
exit(1);
}
err = uc_reg_write(uc, UC_X86_REG_CR3, &tlb_base);
if (err) {
printf("failed to write CR3\n");
exit(1);
}
err = uc_reg_read(uc, UC_X86_REG_CR0, &cr0);
if (err) {
printf("failed to read CR0\n");
exit(1);
}
err = uc_reg_read(uc, UC_X86_REG_CR4, &cr4);
if (err) {
printf("failed to read CR4\n");
exit(1);
}
err = uc_reg_read(uc, UC_X86_REG_MSR, &msr);
if (err) {
printf("failed to read MSR\n");
exit(1);
}
cr0 |= 1; // enable protected mode
cr0 |= 1l << 31; // enable paging
cr4 |= 1l << 5; // enable physical address extension
msr.value |= 1l << 8; // enable long mode
err = uc_reg_write(uc, UC_X86_REG_CR0, &cr0);
if (err) {
printf("failed to write CR0\n");
exit(1);
}
err = uc_reg_write(uc, UC_X86_REG_CR4, &cr4);
if (err) {
printf("failed to write CR4\n");
exit(1);
}
err = uc_reg_write(uc, UC_X86_REG_MSR, &msr);
if (err) {
printf("failed to write MSR\n");
exit(1);
}
}
static void x86_mmu_pt_set(uc_engine *uc, uint64_t vaddr, uint64_t paddr,
uint64_t tlb_base)
{
uint64_t pto = ((vaddr & 0x000000001ff000) >> 12) * 8;
uint32_t pte = (paddr) | 1 | (1 << 2);
uc_mem_write(uc, tlb_base + 0x3000 + pto, &pte, sizeof(pte));
}
static void x86_mmu_syscall_callback(uc_engine *uc, void *userdata)
{
uc_err err;
bool *parrent_done = userdata;
uint64_t rax;
err = uc_reg_read(uc, UC_X86_REG_RAX, &rax);
if (err) {
printf("failed to read rax\n");
exit(1);
}
switch (rax) {
case 57:
/* fork */
break;
case 60:
/* exit */
*parrent_done = true;
uc_emu_stop(uc);
return;
default:
printf("unknown syscall");
exit(1);
}
if (!(*parrent_done)) {
rax = 27;
err = uc_reg_write(uc, UC_X86_REG_RAX, &rax);
if (err) {
printf("failed to write rax\n");
exit(1);
}
uc_emu_stop(uc);
}
}
void cpu_tlb(void)
{
uint64_t tlb_base = 0x3000;
uint64_t rax, rip;
bool parrent_done = false;
uint64_t parrent, child;
uc_context *context;
uc_engine *uc;
uc_err err;
uc_hook h1, h2;
printf("Emulate x86 amd64 code with mmu enabled and switch mappings\n");
err = uc_open(UC_ARCH_X86, UC_MODE_64, &uc);
if (err) {
printf("Failed on uc_open() with error returned: %u\n", err);
exit(1);
}
uc_ctl_tlb_mode(uc, UC_TLB_CPU);
err = uc_context_alloc(uc, &context);
if (err) {
printf("Failed on uc_context_alloc() with error returned: %u\n", err);
exit(1);
}
err = uc_hook_add(uc, &h1, UC_HOOK_INSN, &x86_mmu_syscall_callback,
&parrent_done, 1, 0, UC_X86_INS_SYSCALL);
if (err) {
printf("Failed on uc_hook_add() with error returned: %u\n", err);
exit(1);
}
// Memory hooks are called after the mmu translation, so hook the physicall
// addresses
err = uc_hook_add(uc, &h2, UC_HOOK_MEM_WRITE, &mmu_write_callback, NULL,
0x1000, 0x3000);
if (err) {
printf("Faled on uc_hook_add() with error returned: %u\n", err);
}
printf("map code\n");
err = uc_mem_map(uc, 0x0, 0x1000, UC_PROT_ALL); // Code
if (err) {
printf("Failed on uc_mem_map() with error return: %u\n", err);
exit(1);
}
err = uc_mem_write(uc, 0x0, code, sizeof(code) - 1);
if (err) {
printf("Failed on uc_mem_wirte() with error return: %u\n", err);
exit(1);
}
printf("map parrent memory\n");
err = uc_mem_map(uc, 0x1000, 0x1000, UC_PROT_ALL); // Parrent
if (err) {
printf("Failed on uc_mem_map() with error return: %u\n", err);
exit(1);
}
printf("map child memory\n");
err = uc_mem_map(uc, 0x2000, 0x1000, UC_PROT_ALL); // Child
if (err) {
printf("failed to map child memory\n");
exit(1);
}
printf("map tlb memory\n");
err = uc_mem_map(uc, tlb_base, 0x4000, UC_PROT_ALL); // TLB
if (err) {
printf("failed to map memory for tlb\n");
exit(1);
}
printf("set up the tlb\n");
x86_mmu_prepare_tlb(uc, 0x0, tlb_base);
x86_mmu_pt_set(uc, 0x2000, 0x0, tlb_base);
x86_mmu_pt_set(uc, 0x4000, 0x1000, tlb_base);
err = uc_ctl_flush_tlb(uc);
if (err) {
printf("failed to flush tlb\n");
exit(1);
}
printf("run the parrent\n");
err = uc_emu_start(uc, 0x2000, 0x0, 0, 0);
if (err) {
printf("failed to run parrent\n");
exit(1);
}
printf("save the context for the child\n");
err = uc_context_save(uc, context);
printf("finish the parrent\n");
err = uc_reg_read(uc, UC_X86_REG_RIP, &rip);
if (err) {
printf("failed to read rip\n");
exit(1);
}
err = uc_emu_start(uc, rip, 0x0, 0, 0);
if (err) {
printf("failed to flush tlb\n");
exit(1);
}
printf("restore the context for the child\n");
err = uc_context_restore(uc, context);
if (err) {
printf("failed to restore context\n");
exit(1);
}
x86_mmu_prepare_tlb(uc, 0x0, tlb_base);
x86_mmu_pt_set(uc, 0x4000, 0x2000, tlb_base);
rax = 0;
err = uc_reg_write(uc, UC_X86_REG_RAX, &rax);
if (err) {
printf("failed to write rax\n");
exit(1);
}
err = uc_ctl_flush_tlb(uc);
if (err) {
printf("failed to flush tlb\n");
exit(1);
}
err = uc_emu_start(uc, rip, 0x0, 0, 0);
if (err) {
printf("failed to run child\n");
exit(1);
}
err = uc_mem_read(uc, 0x1000, &parrent, sizeof(parrent));
if (err) {
printf("failed to read from parrent memory\n");
exit(1);
}
err = uc_mem_read(uc, 0x2000, &child, sizeof(child));
if (err) {
printf("failed to read from child memory\n");
exit(1);
}
printf("parrent result == %lu\n", parrent);
printf("child result == %lu\n", child);
uc_close(uc);
}
static bool virtual_tlb_callback(uc_engine *uc, uint64_t addr, uc_mem_type type,
uc_tlb_entry *result, void *user_data)
{
bool *parrent_done = user_data;
printf("tlb lookup for address: 0x%lX\n", addr);
switch (addr & ~(0xfff)) {
case 0x2000:
result->paddr = 0x0;
result->perms = UC_PROT_EXEC;
return true;
case 0x4000:
if (*parrent_done) {
result->paddr = 0x2000;
} else {
result->paddr = 0x1000;
}
result->perms = UC_PROT_READ | UC_PROT_WRITE;
return true;
default:
break;
}
return false;
}
void virtual_tlb(void)
{
uint64_t rax, rip;
bool parrent_done = false;
uint64_t parrent, child;
uc_context *context;
uc_engine *uc;
uc_err err;
uc_hook h1, h2, h3;
printf("Emulate x86 amd64 code with virtual mmu\n");
err = uc_open(UC_ARCH_X86, UC_MODE_64, &uc);
if (err) {
printf("Failed on uc_open() with error returned: %u\n", err);
exit(1);
}
uc_ctl_tlb_mode(uc, UC_TLB_VIRTUAL);
err = uc_context_alloc(uc, &context);
if (err) {
printf("Failed on uc_context_alloc() with error returned: %u\n", err);
exit(1);
}
err = uc_hook_add(uc, &h1, UC_HOOK_INSN, &x86_mmu_syscall_callback,
&parrent_done, 1, 0, UC_X86_INS_SYSCALL);
if (err) {
printf("Failed on uc_hook_add() with error returned: %u\n", err);
exit(1);
}
// Memory hooks are called after the mmu translation, so hook the physicall
// addresses
err = uc_hook_add(uc, &h2, UC_HOOK_MEM_WRITE, &mmu_write_callback, NULL,
0x1000, 0x3000);
if (err) {
printf("Faled on uc_hook_add() with error returned: %u\n", err);
}
printf("map code\n");
err = uc_mem_map(uc, 0x0, 0x1000, UC_PROT_ALL); // Code
if (err) {
printf("Failed on uc_mem_map() with error return: %u\n", err);
exit(1);
}
err = uc_mem_write(uc, 0x0, code, sizeof(code) - 1);
if (err) {
printf("Failed on uc_mem_wirte() with error return: %u\n", err);
exit(1);
}
printf("map parrent memory\n");
err = uc_mem_map(uc, 0x1000, 0x1000, UC_PROT_ALL); // Parrent
if (err) {
printf("Failed on uc_mem_map() with error return: %u\n", err);
exit(1);
}
printf("map child memory\n");
err = uc_mem_map(uc, 0x2000, 0x1000, UC_PROT_ALL); // Child
if (err) {
printf("failed to map child memory\n");
exit(1);
}
err = uc_hook_add(uc, &h3, UC_HOOK_TLB_FILL, virtual_tlb_callback,
&parrent_done, 1, 0);
printf("run the parrent\n");
err = uc_emu_start(uc, 0x2000, 0x0, 0, 0);
if (err) {
printf("failed to run parrent\n");
exit(1);
}
printf("save the context for the child\n");
err = uc_context_save(uc, context);
printf("finish the parrent\n");
err = uc_reg_read(uc, UC_X86_REG_RIP, &rip);
if (err) {
printf("failed to read rip\n");
exit(1);
}
err = uc_emu_start(uc, rip, 0x0, 0, 0);
if (err) {
printf("failed to flush tlb\n");
exit(1);
}
printf("restore the context for the child\n");
err = uc_context_restore(uc, context);
if (err) {
printf("failed to restore context\n");
exit(1);
}
rax = 0;
parrent_done = true;
err = uc_reg_write(uc, UC_X86_REG_RAX, &rax);
if (err) {
printf("failed to write rax\n");
exit(1);
}
err = uc_ctl_flush_tlb(uc);
if (err) {
printf("failed to flush tlb\n");
exit(1);
}
err = uc_emu_start(uc, rip, 0x0, 0, 0);
if (err) {
printf("failed to run child\n");
exit(1);
}
err = uc_mem_read(uc, 0x1000, &parrent, sizeof(parrent));
if (err) {
printf("failed to read from parrent memory\n");
exit(1);
}
err = uc_mem_read(uc, 0x2000, &child, sizeof(child));
if (err) {
printf("failed to read from child memory\n");
exit(1);
}
printf("parrent result == %lu\n", parrent);
printf("child result == %lu\n", child);
uc_close(uc);
}
int main(void)
{
cpu_tlb();
virtual_tlb();
}