3 files changed, 76 insertions, 8 deletions
diff --git a/frida_mode/src/instrument/instrument.c b/frida_mode/src/instrument/instrument.c
index 971f80c0..67eadc3f 100644
--- a/frida_mode/src/instrument/instrument.c
+++ b/frida_mode/src/instrument/instrument.c
@@ -5,6 +5,7 @@
 #include "config.h"
 #include "debug.h"
 
+#include "asan.h"
 #include "entry.h"
 #include "frida_cmplog.h"
 #include "instrument.h"
@@ -33,7 +34,7 @@ __attribute__((hot)) static void on_basic_block(GumCpuContext *context,
    */
   static char buffer[200];
   int         len;
-  guint64     current_pc = (guint64)user_data;
+  GumAddress  current_pc = GUM_ADDRESS(user_data);
   uint8_t *   cursor;
   uint64_t    value;
   if (unlikely(tracing)) {
@@ -85,8 +86,8 @@ static void instr_basic_block(GumStalkerIterator *iterator,
 
     if (begin) {
 
-      prefetch_write((void *)instr->address);
-      if (!range_is_excluded((void *)instr->address)) {
+      prefetch_write(GSIZE_TO_POINTER(instr->address));
+      if (!range_is_excluded(GSIZE_TO_POINTER(instr->address))) {
 
         if (optimize) {
 
@@ -94,8 +95,8 @@ static void instr_basic_block(GumStalkerIterator *iterator,
 
         } else {
 
-          gum_stalker_iterator_put_callout(iterator, on_basic_block,
-                                           (gpointer)instr->address, NULL);
+          gum_stalker_iterator_put_callout(
+              iterator, on_basic_block, GSIZE_TO_POINTER(instr->address), NULL);
 
         }
 
@@ -105,8 +106,9 @@ static void instr_basic_block(GumStalkerIterator *iterator,
 
     }
 
-    if (!range_is_excluded((void *)instr->address)) {
+    if (!range_is_excluded(GSIZE_TO_POINTER(instr->address))) {
 
+      asan_instrument(instr, iterator);
       cmplog_instrument(instr, iterator);
 
     }
@@ -142,6 +144,7 @@ void instrument_init(void) {
   transformer =
       gum_stalker_transformer_make_from_callback(instr_basic_block, NULL, NULL);
 
+  asan_init();
   cmplog_init();
 
 }
diff --git a/frida_mode/src/instrument/instrument_arm32.c b/frida_mode/src/instrument/instrument_arm32.c
index c2d720a7..1a3c40bb 100644
--- a/frida_mode/src/instrument/instrument_arm32.c
+++ b/frida_mode/src/instrument/instrument_arm32.c
@@ -3,6 +3,7 @@
 #include "debug.h"
 
 #include "instrument.h"
+#include "util.h"
 
 #if defined(__arm__)
 
@@ -15,6 +16,8 @@ gboolean instrument_is_coverage_optimize_supported(void) {
 void instrument_coverage_optimize(const cs_insn *   instr,
                                   GumStalkerOutput *output) {
 
+  UNUSED_PARAMETER(instr);
+  UNUSED_PARAMETER(output);
   FATAL("Optimized coverage not supported on this architecture");
 
 }
diff --git a/frida_mode/src/instrument/instrument_x86.c b/frida_mode/src/instrument/instrument_x86.c
index 5b8cbbba..585bb5b8 100644
--- a/frida_mode/src/instrument/instrument_x86.c
+++ b/frida_mode/src/instrument/instrument_x86.c
@@ -3,19 +3,81 @@
 #include "debug.h"
 
 #include "instrument.h"
+#include "util.h"
 
 #if defined(__i386__)
 
+static GumAddress current_log_impl = GUM_ADDRESS(0);
+
+static void instrument_coverage_function(GumX86Writer *cw) {
+
+  gum_x86_writer_put_pushfx(cw);
+  gum_x86_writer_put_push_reg(cw, GUM_REG_ECX);
+  gum_x86_writer_put_push_reg(cw, GUM_REG_EDX);
+
+  gum_x86_writer_put_mov_reg_address(cw, GUM_REG_ECX,
+                                     GUM_ADDRESS(&previous_pc));
+  gum_x86_writer_put_mov_reg_reg_ptr(cw, GUM_REG_EDX, GUM_REG_ECX);
+  gum_x86_writer_put_xor_reg_reg(cw, GUM_REG_EDX, GUM_REG_EDI);
+
+  gum_x86_writer_put_add_reg_imm(cw, GUM_REG_EDX, GUM_ADDRESS(__afl_area_ptr));
+
+  /* add byte ptr [edx], 1 */
+  uint8_t add_byte_ptr_edx_1[] = {0x80, 0x02, 0x01};
+  gum_x86_writer_put_bytes(cw, add_byte_ptr_edx_1, sizeof(add_byte_ptr_edx_1));
+
+  /* adc byte ptr [edx], 0 */
+  uint8_t adc_byte_ptr_edx_0[] = {0x80, 0x12, 0x00};
+  gum_x86_writer_put_bytes(cw, adc_byte_ptr_edx_0, sizeof(adc_byte_ptr_edx_0));
+
+  gum_x86_writer_put_shr_reg_u8(cw, GUM_REG_EDI, 1);
+  gum_x86_writer_put_mov_reg_ptr_reg(cw, GUM_REG_ECX, GUM_REG_EDI);
+
+  gum_x86_writer_put_pop_reg(cw, GUM_REG_EDX);
+  gum_x86_writer_put_pop_reg(cw, GUM_REG_ECX);
+  gum_x86_writer_put_popfx(cw);
+  gum_x86_writer_put_ret(cw);
+
+}
+
 gboolean instrument_is_coverage_optimize_supported(void) {
 
-  return false;
+  return true;
 
 }
 
 void instrument_coverage_optimize(const cs_insn *   instr,
                                   GumStalkerOutput *output) {
 
-  FATAL("Optimized coverage not supported on this architecture");
+  UNUSED_PARAMETER(instr);
+  UNUSED_PARAMETER(output);
+
+  guint64 current_pc = instr->address;
+  guint64 area_offset = (current_pc >> 4) ^ (current_pc << 8);
+  area_offset &= MAP_SIZE - 1;
+  GumX86Writer *cw = output->writer.x86;
+
+  if (current_log_impl == 0 ||
+      !gum_x86_writer_can_branch_directly_between(cw->pc, current_log_impl) ||
+      !gum_x86_writer_can_branch_directly_between(cw->pc + 128,
+                                                  current_log_impl)) {
+
+    gconstpointer after_log_impl = cw->code + 1;
+
+    gum_x86_writer_put_jmp_near_label(cw, after_log_impl);
+
+    current_log_impl = cw->pc;
+    instrument_coverage_function(cw);
+
+    gum_x86_writer_put_label(cw, after_log_impl);
+
+  }
+
+  // gum_x86_writer_put_breakpoint(cw);
+  gum_x86_writer_put_push_reg(cw, GUM_REG_EDI);
+  gum_x86_writer_put_mov_reg_address(cw, GUM_REG_EDI, area_offset);
+  gum_x86_writer_put_call_address(cw, current_log_impl);
+  gum_x86_writer_put_pop_reg(cw, GUM_REG_EDI);
 
 }