127 lines
3.1 KiB
C
127 lines
3.1 KiB
C
#include <stdlib.h>
|
|
#include <stdio.h>
|
|
#include <assert.h>
|
|
|
|
#include <unicorn/unicorn.h>
|
|
|
|
#define X86_CODE32 "\x9C\x68\xFF\xFE\xFF\xFF\x9D\x9C\x58\x9D" // pushf; push ffffffeff; popf; pushf; pop eax; popf
|
|
#define ADDRESS 0x1000000
|
|
#define PAGE_8K (1 << 13)
|
|
#define PAGE_4K (1 << 12)
|
|
#define TARGET_PAGE_MASK ~(PAGE_4K - 1)
|
|
#define TARGET_PAGE_PREPARE(addr) (((addr) + PAGE_4K - 1) & TARGET_PAGE_MASK)
|
|
#define TARGET_PAGE_ALIGN(addr) (addr - (TARGET_PAGE_PREPARE(addr) - addr) & TARGET_PAGE_MASK)
|
|
|
|
#if defined(__i386__)
|
|
typedef uint32_t puint;
|
|
#define PRIX3264 PRIX32
|
|
#else
|
|
typedef uint64_t puint;
|
|
#define PRIX3264 PRIX64
|
|
#endif
|
|
|
|
uint32_t realEflags()
|
|
{
|
|
puint val = 0;
|
|
|
|
#if defined(__i386__)
|
|
puint i = 0xFFFFFEFF; //attempt to set ALL bits except trap flag.
|
|
|
|
__asm__("pushf\n\t"
|
|
"push %0\n\t"
|
|
"popf\n\t"
|
|
"pushf\n\t"
|
|
"pop %0\n\t"
|
|
"popf"
|
|
: "=r"(val)
|
|
: "r"(i)
|
|
: "%0");
|
|
#elif defined(__x86_64__)
|
|
puint i = 0xFFFFFEFF; //attempt to set ALL bits except trap flag.
|
|
|
|
__asm__("pushfq\n\t"
|
|
"pushq %0\n\t"
|
|
"popfq\n\t"
|
|
"pushfq\n\t"
|
|
"popq %0\n\t"
|
|
"popfq"
|
|
: "=r"(val)
|
|
: "r"(i)
|
|
: "%0");
|
|
#endif
|
|
|
|
printf("Real system eflags: 0x%08"PRIX3264"\n", val);
|
|
|
|
return (uint32_t)val & 0xFFFFFFFF;
|
|
}
|
|
|
|
static void VM_exec()
|
|
{
|
|
#if defined(__i386__) || defined(__x86_64__)
|
|
uc_engine *uc;
|
|
uc_err err;
|
|
unsigned int r_eax, eflags, r_esp, realflags = 0;
|
|
|
|
r_eax = 0;
|
|
r_esp = ADDRESS+0x100; //some safe distance from main code.
|
|
eflags = 0x00000206;
|
|
|
|
// Initialize emulator in X86-32bit mode
|
|
err = uc_open(UC_ARCH_X86, UC_MODE_32, &uc);
|
|
if(err)
|
|
{
|
|
printf("Failed on uc_open() with error returned: %s\n", uc_strerror(err));
|
|
return;
|
|
}
|
|
|
|
err = uc_mem_map(uc, ADDRESS, (2 * 1024 * 1024), UC_PROT_ALL);
|
|
if(err != UC_ERR_OK)
|
|
{
|
|
printf("Failed to map memory %s\n", uc_strerror(err));
|
|
return;
|
|
}
|
|
|
|
// write machine code to be emulated to memory
|
|
err = uc_mem_write(uc, ADDRESS, X86_CODE32, sizeof(X86_CODE32) - 1);
|
|
if(err != UC_ERR_OK)
|
|
{
|
|
printf("Failed to write emulation code to memory, quit!: %s(len %lu)\n", uc_strerror(err), (unsigned long)sizeof(X86_CODE32) - 1);
|
|
return;
|
|
}
|
|
|
|
// initialize machine registers
|
|
uc_reg_write(uc, UC_X86_REG_EAX, &r_eax);
|
|
uc_reg_write(uc, UC_X86_REG_ESP, &r_esp); //make stack pointer point to already mapped memory so we don't need to hook.
|
|
uc_reg_write(uc, UC_X86_REG_EFLAGS, &eflags);
|
|
|
|
// emulate machine code in infinite time
|
|
err = uc_emu_start(uc, ADDRESS, ADDRESS + (sizeof(X86_CODE32) - 1), 0, 0);
|
|
if(err)
|
|
{
|
|
printf("Failed on uc_emu_start() with error returned %u: %s\n", err, uc_strerror(err));
|
|
|
|
uc_close(uc);
|
|
return;
|
|
}
|
|
|
|
uc_reg_read(uc, UC_X86_REG_EAX, &r_eax);
|
|
uc_reg_read(uc, UC_X86_REG_EFLAGS, &eflags);
|
|
|
|
uc_close(uc);
|
|
|
|
printf(">>> Emulation done. Below is the CPU context\n");
|
|
printf(">>> EAX = 0x%08X\n", r_eax);
|
|
printf(">>> EFLAGS = 0x%08X\n", eflags);
|
|
|
|
realflags = realEflags();
|
|
|
|
assert(r_eax == realflags);
|
|
#endif
|
|
}
|
|
|
|
int main(int argc, char *argv[])
|
|
{
|
|
VM_exec();
|
|
return 0;
|
|
}
|