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#include "frida-gumjs.h"
#include "instrument.h"
#include "stalker.h"
#include "util.h"
#if defined(__i386__)
gboolean instrument_cache_enabled = FALSE;
gsize instrument_cache_size = 0;
static GHashTable *coverage_blocks = NULL;
#pragma pack(push, 1)
typedef struct {
// cur_location = (block_address >> 4) ^ (block_address << 8);
// shared_mem[cur_location ^ prev_location]++;
// prev_location = cur_location >> 1;
uint8_t mov_eax_esp_4[4];
uint8_t lahf;
uint8_t mov_eax_esp_8[4];
uint8_t mov_ebx_esp_c[4];
uint8_t mov_eax_prev_loc[5];
uint8_t mov_prev_loc_curr_loc_shr1[10];
uint8_t xor_eax_curr_loc[5];
uint8_t add_eax_area_ptr[5];
uint8_t mov_ebx_ptr_eax[2];
uint8_t add_bl_1[3];
uint8_t adc_bl_0[3];
uint8_t mov_ptr_eax_ebx[2];
uint8_t mov_esp_c_ebx[4];
uint8_t mov_esp_8_eax[4];
uint8_t sahf;
uint8_t mov_esp_4_eax[4];
} afl_log_code_asm_t;
#pragma pack(pop)
typedef union {
afl_log_code_asm_t code;
uint8_t bytes[0];
} afl_log_code;
static const afl_log_code_asm_t template =
{
.mov_eax_esp_4 = {0x89, 0x44, 0x24, 0xFC},
.lahf = 0x9f,
.mov_eax_esp_8 = {0x89, 0x44, 0x24, 0xF8},
.mov_ebx_esp_c = {0x89, 0x5C, 0x24, 0xF4},
.mov_eax_prev_loc = {0xA1},
.mov_prev_loc_curr_loc_shr1 = {0xc7, 0x05},
.xor_eax_curr_loc = {0x35},
.add_eax_area_ptr = {0x05},
.mov_ebx_ptr_eax = {0x8a, 0x18},
.add_bl_1 = {0x80, 0xc3, 0x01},
.adc_bl_0 = {0x80, 0xd3, 0x00},
.mov_ptr_eax_ebx = {0x88, 0x18},
.mov_esp_c_ebx = {0x8B, 0x5C, 0x24, 0xF4},
.mov_esp_8_eax = {0x8B, 0x44, 0x24, 0xF8},
.sahf = 0x9e,
.mov_esp_4_eax = {0x8B, 0x44, 0x24, 0xFC},
}
;
gboolean instrument_is_coverage_optimize_supported(void) {
return true;
}
static void instrument_coverage_switch(GumStalkerObserver *self,
gpointer from_address,
gpointer start_address,
const cs_insn *from_insn,
gpointer *target) {
UNUSED_PARAMETER(self);
UNUSED_PARAMETER(from_address);
UNUSED_PARAMETER(start_address);
cs_x86 *x86;
cs_x86_op *op;
if (from_insn == NULL) { return; }
x86 = &from_insn->detail->x86;
op = x86->operands;
if (!g_hash_table_contains(coverage_blocks, GSIZE_TO_POINTER(*target))) {
return;
}
switch (from_insn->id) {
case X86_INS_CALL:
case X86_INS_JMP:
if (x86->op_count != 1) {
FATAL("Unexpected operand count: %d", x86->op_count);
}
if (op[0].type != X86_OP_IMM) { return; }
break;
case X86_INS_RET:
break;
default:
return;
}
*target = (guint8 *)*target + sizeof(afl_log_code);
}
static void instrument_coverage_suppress_init(void) {
static gboolean initialized = false;
if (initialized) { return; }
initialized = true;
GumStalkerObserver *observer = stalker_get_observer();
GumStalkerObserverInterface *iface = GUM_STALKER_OBSERVER_GET_IFACE(observer);
iface->switch_callback = instrument_coverage_switch;
coverage_blocks = g_hash_table_new(g_direct_hash, g_direct_equal);
if (coverage_blocks == NULL) {
FATAL("Failed to g_hash_table_new, errno: %d", errno);
}
}
void instrument_coverage_optimize(const cs_insn *instr,
GumStalkerOutput *output) {
afl_log_code code = {0};
GumX86Writer *cw = output->writer.x86;
guint64 area_offset = instrument_get_offset_hash(GUM_ADDRESS(instr->address));
gsize map_size_pow2;
gsize area_offset_ror;
if (instrument_previous_pc_addr == NULL) {
GumAddressSpec spec = {.near_address = cw->code,
.max_distance = 1ULL << 30};
guint page_size = gum_query_page_size();
instrument_previous_pc_addr = gum_memory_allocate_near(
&spec, sizeof(guint64), page_size, GUM_PAGE_READ | GUM_PAGE_WRITE);
*instrument_previous_pc_addr = instrument_hash_zero;
FVERBOSE("instrument_previous_pc_addr: %p", instrument_previous_pc_addr);
FVERBOSE("code_addr: %p", cw->code);
}
code.code = template;
instrument_coverage_suppress_init();
// gum_x86_writer_put_breakpoint(cw);
if (!g_hash_table_add(coverage_blocks, GSIZE_TO_POINTER(cw->code))) {
FATAL("Failed - g_hash_table_add");
}
gssize prev_loc_value_offset2 =
offsetof(afl_log_code, code.mov_eax_prev_loc) +
sizeof(code.code.mov_eax_prev_loc) - sizeof(gint);
*((gint *)&code.bytes[prev_loc_value_offset2]) =
(gint)GPOINTER_TO_SIZE(instrument_previous_pc_addr);
gssize curr_loc_shr_1_offset =
offsetof(afl_log_code, code.mov_prev_loc_curr_loc_shr1) +
sizeof(code.code.mov_prev_loc_curr_loc_shr1) - sizeof(guint32);
map_size_pow2 = util_log2(__afl_map_size);
area_offset_ror = util_rotate(area_offset, 1, map_size_pow2);
*((guint32 *)&code.bytes[curr_loc_shr_1_offset]) = (guint32)(area_offset_ror);
gssize prev_loc_value_offset =
offsetof(afl_log_code, code.mov_prev_loc_curr_loc_shr1) +
sizeof(code.code.mov_prev_loc_curr_loc_shr1) - sizeof(gint) -
sizeof(guint32);
*((gint *)&code.bytes[prev_loc_value_offset]) =
(gint)GPOINTER_TO_SIZE(instrument_previous_pc_addr);
gssize xor_curr_loc_offset = offsetof(afl_log_code, code.xor_eax_curr_loc) +
sizeof(code.code.xor_eax_curr_loc) -
sizeof(guint32);
*((guint32 *)&code.bytes[xor_curr_loc_offset]) = (guint32)area_offset;
gssize add_area_ptr_offset = offsetof(afl_log_code, code.add_eax_area_ptr) +
sizeof(code.code.add_eax_area_ptr) -
sizeof(guint32);
*((guint32 *)&code.bytes[add_area_ptr_offset]) = (guint32)__afl_area_ptr;
gum_x86_writer_put_bytes(cw, code.bytes, sizeof(afl_log_code));
}
void instrument_coverage_optimize_insn(const cs_insn *instr,
GumStalkerOutput *output) {
UNUSED_PARAMETER(instr);
UNUSED_PARAMETER(output);
}
void instrument_coverage_optimize_init(void) {
}
void instrument_flush(GumStalkerOutput *output) {
gum_x86_writer_flush(output->writer.x86);
}
gpointer instrument_cur(GumStalkerOutput *output) {
return gum_x86_writer_cur(output->writer.x86);
}
void instrument_cache_config(void) {
}
void instrument_cache_init(void) {
}
void instrument_cache_insert(gpointer real_address, gpointer code_address) {
UNUSED_PARAMETER(real_address);
UNUSED_PARAMETER(code_address);
}
void instrument_cache(const cs_insn *instr, GumStalkerOutput *output) {
UNUSED_PARAMETER(instr);
UNUSED_PARAMETER(output);
}
void instrument_write_regs(GumCpuContext *cpu_context, gpointer user_data) {
int fd = (int)(size_t)user_data;
instrument_regs_format(
fd, "eax: 0x%08x, ebx: 0x%08x, ecx: 0x%08x, edx: 0x%08x\n",
cpu_context->eax, cpu_context->ebx, cpu_context->ecx, cpu_context->edx);
instrument_regs_format(
fd, "esi: 0x%08x, edi: 0x%08x, ebp: 0x%08x, esp: 0x%08x\n",
cpu_context->esi, cpu_context->edi, cpu_context->ebp, cpu_context->esp);
instrument_regs_format(fd, "eip: 0x%08x\n\n", cpu_context->eip);
}
#endif
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