unicorn/regress/ro_mem_test.c

142 lines
4.0 KiB
C
Executable File

#include <inttypes.h>
#include <string.h>
#include <unistd.h>
#include <unicorn/unicorn.h>
const uint8_t PROGRAM[] = "\xeb\x08\x58\xc7\x00\x78\x56\x34\x12\x90\xe8\xf3\xff\xff\xff";
/*
bits 32
jmp short bottom
top:
pop eax
mov dword [eax], 0x12345678
nop
bottom:
call top
*/
// callback for tracing instruction
static void hook_code(uch handle, uint64_t address, uint32_t size, void *user_data)
{
uint32_t esp;
printf(">>> Tracing instruction at 0x%"PRIx64 ", instruction size = 0x%x\n", address, size);
uc_reg_read(handle, UC_X86_REG_ESP, &esp);
printf(">>> --- ESP is 0x%x\n", esp);
}
// callback for tracing memory access (READ or WRITE)
static bool hook_mem_invalid(uch handle, uc_mem_type type,
uint64_t address, int size, int64_t value, void *user_data)
{
uint32_t esp;
uc_reg_read(handle, UC_X86_REG_ESP, &esp);
switch(type) {
default:
// return false to indicate we want to stop emulation
return false;
case UC_MEM_WRITE:
//if this is a push, esp has not been adjusted yet
if (esp == (address + size)) {
uint32_t upper;
upper = (esp + 0xfff) & ~0xfff;
printf(">>> Stack appears to be missing at 0x%"PRIx64 ", allocating now\n", address);
// map this memory in with 2MB in size
uc_mem_map(handle, upper - 0x8000, 0x8000);
// return true to indicate we want to continue
return true;
}
printf(">>> Missing memory is being WRITE at 0x%"PRIx64 ", data size = %u, data value = 0x%"PRIx64 "\n",
address, size, value);
return false;
}
}
#define STACK 0x500000
#define STACK_SIZE 0x5000
int main(int argc, char **argv, char **envp) {
uch handle, trace1, trace2;
uc_err err;
uint8_t bytes[8];
uint32_t esp;
int result;
int map_stack = 0;
if (argc == 2 && strcmp(argv[1], "--map-stack") == 0) {
map_stack = 1;
}
printf("Memory mapping test\n");
if (map_stack) {
printf("Pre-mapping stack\n");
}
else {
printf("Mapping stack on first invalid memory access\n");
}
// Initialize emulator in X86-32bit mode
err = uc_open(UC_ARCH_X86, UC_MODE_32, &handle);
if (err) {
printf("Failed on uc_open() with error returned: %u\n", err);
return 1;
}
uc_mem_map(handle, 0x100000, 0x1000);
uc_mem_map(handle, 0x200000, 0x2000);
uc_mem_map(handle, 0x300000, 0x3000);
uc_mem_map_ex(handle, 0x400000, 0x4000, UC_PROT_READ | UC_PROT_EXEC);
if (map_stack) {
uc_mem_map_ex(handle, STACK, STACK_SIZE, UC_PROT_READ | UC_PROT_WRITE);
}
esp = STACK + STACK_SIZE;
uc_reg_write(handle, UC_X86_REG_ESP, &esp);
// write machine code to be emulated to memory
if (uc_mem_write(handle, 0x400000, PROGRAM, sizeof(PROGRAM))) {
printf("Failed to write emulation code to memory, quit!\n");
return 2;
}
else {
printf("Allowed to write to read only memory via uc_mem_write\n");
}
//uc_hook_add(handle, &trace2, UC_HOOK_CODE, hook_code, NULL, (uint64_t)0x400000, (uint64_t)0x400fff);
// intercept invalid memory events
uc_hook_add(handle, &trace1, UC_HOOK_MEM_INVALID, hook_mem_invalid, NULL);
// emulate machine code in infinite time
printf("BEGIN execution\n");
err = uc_emu_start(handle, 0x400000, 0x400000 + sizeof(PROGRAM), 0, 5);
if (err) {
printf("Failed on uc_emu_start() with error returned %u: %s\n",
err, uc_strerror(err));
return 3;
}
printf("END execution\n");
printf("Verifying content at bottom of stack is readable and correct\n");
if (!uc_mem_read(handle, esp - 4, bytes, 4)) {
printf(">>> Read 4 bytes from [0x%x] = 0x%x\n", (uint32_t)(esp - 4), *(uint32_t*) bytes);
}
else {
printf(">>> Failed to read 4 bytes from [0x%x]\n", (uint32_t)(esp - 4));
return 4;
}
uc_close(&handle);
return 0;
}