Merge pull request #50 from vanhauser-thc/uc_compcov

Unicorn CompareCoverage + Neverzero counters

3 files changed, 71 insertions, 16 deletions

diff --git a/qemu_mode/patches/afl-qemu-common.h b/qemu_mode/patches/afl-qemu-common.h
new file mode 100644
index 00000000..8013800d
--- /dev/null
+++ b/qemu_mode/patches/afl-qemu-common.h
@@ -0,0 +1,52 @@
+/*
+   american fuzzy lop - high-performance binary-only instrumentation
+   -----------------------------------------------------------------
+
+   Written by Andrew Griffiths <agriffiths@google.com> and
+              Michal Zalewski <lcamtuf@google.com>
+
+   Idea & design very much by Andrew Griffiths.
+
+   TCG instrumentation and block chaining support by Andrea Biondo
+                                      <andrea.biondo965@gmail.com>
+
+   QEMU 3.1.0 port, TCG thread-safety and CompareCoverage by Andrea Fioraldi
+                                      <andreafioraldi@gmail.com>
+
+   Copyright 2015, 2016, 2017 Google Inc. All rights reserved.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at:
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+   This code is a shim patched into the separately-distributed source
+   code of QEMU 3.1.0. It leverages the built-in QEMU tracing functionality
+   to implement AFL-style instrumentation and to take care of the remaining
+   parts of the AFL fork server logic.
+
+   The resulting QEMU binary is essentially a standalone instrumentation
+   tool; for an example of how to leverage it for other purposes, you can
+   have a look at afl-showmap.c.
+
+ */
+
+#include "../../config.h"
+
+/* NeverZero */ 
+
+#if (defined(__x86_64__) || defined(__i386__)) && defined(AFL_QEMU_NOT_ZERO)
+#  define INC_AFL_AREA(loc) \
+    asm volatile ( \
+      "incb (%0, %1, 1)\n" \
+      "adcb $0, (%0, %1, 1)\n" \
+      : /* no out */ \
+      : "r" (afl_area_ptr), "r" (loc) \
+      : "memory", "eax" \
+    )
+#else
+#  define INC_AFL_AREA(loc) \
+  afl_area_ptr[loc]++
+#endif
+
diff --git a/qemu_mode/patches/afl-qemu-cpu-translate-inl.h b/qemu_mode/patches/afl-qemu-cpu-translate-inl.h
index 4716c2ac..fc78e652 100644
--- a/qemu_mode/patches/afl-qemu-cpu-translate-inl.h
+++ b/qemu_mode/patches/afl-qemu-cpu-translate-inl.h
@@ -32,7 +32,7 @@
 
  */
 
-#include "../../config.h"
+#include "afl-qemu-common.h"
 #include "tcg.h"
 #include "tcg-op.h"
 
@@ -49,7 +49,7 @@ static void afl_compcov_log_16(target_ulong cur_loc, target_ulong arg1,
                                target_ulong arg2) {
 
   if ((arg1 & 0xff) == (arg2 & 0xff)) {
-    afl_area_ptr[cur_loc]++;
+    INC_AFL_AREA(cur_loc);
   }
 }
 
@@ -57,11 +57,11 @@ static void afl_compcov_log_32(target_ulong cur_loc, target_ulong arg1,
                                target_ulong arg2) {
 
   if ((arg1 & 0xff) == (arg2 & 0xff)) {
-    afl_area_ptr[cur_loc]++;
+    INC_AFL_AREA(cur_loc);
     if ((arg1 & 0xffff) == (arg2 & 0xffff)) {
-      afl_area_ptr[cur_loc +1]++;
+      INC_AFL_AREA(cur_loc +1);
       if ((arg1 & 0xffffff) == (arg2 & 0xffffff)) {
-        afl_area_ptr[cur_loc +2]++;
+        INC_AFL_AREA(cur_loc +2);
       }
     }
   }
@@ -71,19 +71,19 @@ static void afl_compcov_log_64(target_ulong cur_loc, target_ulong arg1,
                                target_ulong arg2) {
 
   if ((arg1 & 0xff) == (arg2 & 0xff)) {
-    afl_area_ptr[cur_loc]++;
+    INC_AFL_AREA(cur_loc);
     if ((arg1 & 0xffff) == (arg2 & 0xffff)) {
-      afl_area_ptr[cur_loc +1]++;
+      INC_AFL_AREA(cur_loc +1);
       if ((arg1 & 0xffffff) == (arg2 & 0xffffff)) {
-        afl_area_ptr[cur_loc +2]++;
+        INC_AFL_AREA(cur_loc +2);
         if ((arg1 & 0xffffffff) == (arg2 & 0xffffffff)) {
-          afl_area_ptr[cur_loc +3]++;
+          INC_AFL_AREA(cur_loc +3);
           if ((arg1 & 0xffffffffff) == (arg2 & 0xffffffffff)) {
-            afl_area_ptr[cur_loc +4]++;
+            INC_AFL_AREA(cur_loc +4);
             if ((arg1 & 0xffffffffffff) == (arg2 & 0xffffffffffff)) {
-              afl_area_ptr[cur_loc +5]++;
+              INC_AFL_AREA(cur_loc +5);
               if ((arg1 & 0xffffffffffffff) == (arg2 & 0xffffffffffffff)) {
-                afl_area_ptr[cur_loc +6]++;
+                INC_AFL_AREA(cur_loc +6);
               }
             }
           }
@@ -120,7 +120,7 @@ static void afl_gen_compcov(target_ulong cur_loc, TCGv_i64 arg1, TCGv_i64 arg2,
   }
   
   cur_loc  = (cur_loc >> 4) ^ (cur_loc << 8);
-  cur_loc &= MAP_SIZE - 1;
+  cur_loc &= MAP_SIZE - 7;
   
   if (cur_loc >= afl_inst_rms) return;
   
diff --git a/qemu_mode/patches/afl-qemu-translate-inl.h b/qemu_mode/patches/afl-qemu-translate-inl.h
index bfb2897e..d63c5167 100644
--- a/qemu_mode/patches/afl-qemu-translate-inl.h
+++ b/qemu_mode/patches/afl-qemu-translate-inl.h
@@ -32,7 +32,7 @@
 
  */
 
-#include "../../config.h"
+#include "afl-qemu-common.h"
 #include "tcg-op.h"
 
 /* Declared in afl-qemu-cpu-inl.h */
@@ -42,11 +42,14 @@ extern abi_ulong afl_start_code, afl_end_code;
 
 void tcg_gen_afl_maybe_log_call(target_ulong cur_loc);
 
-void afl_maybe_log(target_ulong cur_loc) { 
+void afl_maybe_log(target_ulong cur_loc) {
 
   static __thread abi_ulong prev_loc;
 
-  afl_area_ptr[cur_loc ^ prev_loc]++;
+  register uintptr_t afl_idx = cur_loc ^ prev_loc;
+
+  INC_AFL_AREA(afl_idx);
+
   prev_loc = cur_loc >> 1;
 
 }