测试代码
/* Unicorn Emulator Engine */
/* By Nguyen Anh Quynh, 2015 */
/* Sample code to demonstrate how to emulate ARM code */
#include <unicorn/unicorn.h>
#include <string.h>
// code to be emulated
#define THUMB_CODE "\x10\xb5\x4f\xf6\x00\x74\xe8\xbf\x10\xbd"
// memory address where emulation starts
int STACK_MEMORY_BASE = 0x00000000;
int STACK_MEMORY_SIZE = 0x00800000;
int HOOK_MEMORY_BASE = 0x1000000;
int HOOK_MEMORY_SIZE = 0x0800000;
static void hook_code(uc_engine *uc, uint64_t address, uint32_t size, void *user_data)
{
unsigned char bytes[8];
char instruction[32] = {0};
int i = 0;
uc_mem_read(uc,address,bytes,size);
for(i = 0; i < size; i++){
sprintf(instruction + i * 3,"%02x ", bytes[i]);
}
printf(">>> Tracing instruction at 0x%"PRIx64 ", instruction size = 0x%x, instruction = %s\n", address, size, instruction);
}
unsigned char bytes[32];
char instruction[64] = {0};
static void test_thumb(void)
{
uc_engine *uc;
uc_err err;
uc_hook trace2;
int sp = 1024; // R0 register
int code_length;
printf("Emulate THUMB code\n");
// Initialize emulator in ARM mode
err = uc_open(UC_ARCH_ARM, UC_MODE_THUMB, &uc);
if (err) {
printf("Failed on uc_open() with error returned: %u (%s)\n",
err, uc_strerror(err));
return;
}
// map 2MB memory for this emulation
uc_mem_map(uc, HOOK_MEMORY_BASE, HOOK_MEMORY_SIZE, UC_PROT_ALL);
uc_mem_map(uc, STACK_MEMORY_BASE, STACK_MEMORY_SIZE, UC_PROT_ALL);
// write machine code to be emulated to memory
code_length = sizeof(THUMB_CODE) - 1;
uc_mem_write(uc, HOOK_MEMORY_BASE, THUMB_CODE, code_length);
// initialize machine registers
int lr = HOOK_MEMORY_BASE + 0x80;
sp = STACK_MEMORY_BASE + STACK_MEMORY_SIZE;
uc_reg_write(uc, UC_ARM_REG_SP, &sp);
printf(">>> SP = 0x%x\n", sp);
uc_reg_write(uc, UC_ARM_REG_LR, &lr);
// tracing all basic blocks with customized callback
//uc_hook_add(uc, &trace1, UC_HOOK_BLOCK, hook_block, NULL, 1, 0);
// tracing one instruction at ADDRESS with customized callback
uc_hook_add(uc, &trace2, UC_HOOK_CODE, hook_code, NULL, HOOK_MEMORY_BASE, HOOK_MEMORY_BASE + HOOK_MEMORY_SIZE);
// emulate machine code in infinite time (last param = 0), or when
// finishing all the code.
// Note we start at ADDRESS | 1 to indicate THUMB mode.
err = uc_emu_start(uc, (HOOK_MEMORY_BASE) | 1, lr, 0, 0);
if (err) {
printf("Failed on uc_emu_start() with error returned: %u\n", err);
}
// now print out some registers
printf(">>> Emulation done. Below is the CPU context\n");
uc_reg_read(uc, UC_ARM_REG_SP, &sp);
printf(">>> SP = 0x%x\n", sp);
uc_close(uc);
}
int main(int argc, char **argv, char **envp)
{
// dynamically load shared library
#ifdef DYNLOAD
if (!uc_dyn_load(NULL, 0)) {
printf("Error dynamically loading shared library.\n");
printf("Please check that unicorn.dll/unicorn.so is available as well as\n");
printf("any other dependent dll/so files.\n");
printf("The easiest way is to place them in the same directory as this app.\n");
return 1;
}
#endif
// test_arm();
printf("==========================\n");
test_thumb();
// dynamically free shared library
#ifdef DYNLOAD
uc_dyn_free();
#endif
return 0;
}
V1.0.2 输出
==========================
Emulate THUMB code
>>> SP = 0x800000
>>> Tracing instruction at 0x1000000, instruction size = 0x2, instruction = 10 b5
>>> Tracing instruction at 0x1000002, instruction size = 0x4, instruction = 4f f6 00 74
>>> Tracing instruction at 0x1000006, instruction size = 0x2, instruction = e8 bf
>>> Tracing instruction at 0x1000008, instruction size = 0x2, instruction = 10 bd
>>> Emulation done. Below is the CPU context
>>> SP = 0x800000
V1.0.3 输出
==========================
Emulate THUMB code
>>> SP = 0x800000
thumb insn: 0xb510
thumb insn: 0xb510 gen_uc_tracecode
thumb2:insn: 0xf64f
thumb insn: 0xbfe8
>>> Tracing instruction at 0x1000000, instruction size = 0x2, instruction = 10 b5
>>> Tracing instruction at 0x1000002, instruction size = 0x4, instruction = 4f f6 00 74
>>> Emulation done. Below is the CPU context
>>> SP = 0x800000
尝试修复
修复的具体进展:issues #1412
笔者通过自己阅读源代码发现,可能是修复 issues #853引入的BUG,代码差异:
qemu/target-arm/translate.c
- Version 1.0.2
default:
gen_uc_tracecode(tcg_ctx, 2, UC_HOOK_CODE_IDX, s->uc, s->pc);
- Version 1.0.3
default:
if (!((insn & 0xff00) == 0xbf00)){
gen_uc_tracecode(tcg_ctx, 2, UC_HOOK_CODE_IDX, s->uc, s->pc);
}
但是简单还原为1.0.2的代码,也不能正常运行。期待issues #1412的解决。
Comments