Merge pull request #1592 from AFLplusplus/dev

Dev

28 files changed, 347 insertions, 80 deletions

diff --git a/GNUmakefile b/GNUmakefile
index c8f7f35a..6b55635f 100644
--- a/GNUmakefile
+++ b/GNUmakefile
@@ -91,9 +91,8 @@ ifneq "$(SYS)" "Darwin"
   #ifeq "$(HAVE_MARCHNATIVE)" "1"
   #  SPECIAL_PERFORMANCE += -march=native
   #endif
- # OS X does not like _FORTIFY_SOURCE=2
  ifndef DEBUG
-   CFLAGS_OPT += -D_FORTIFY_SOURCE=2
+   CFLAGS_OPT += -D_FORTIFY_SOURCE=1
  endif
 else
   # On some odd MacOS system configurations, the Xcode sdk path is not set correctly
@@ -103,7 +102,7 @@ endif
 
 ifeq "$(SYS)" "SunOS"
   CFLAGS_OPT += -Wno-format-truncation
-  LDFLAGS = -lkstat -lrt
+  LDFLAGS = -lkstat -lrt -lsocket -lnsl
 endif
 
 ifdef STATIC
diff --git a/GNUmakefile.gcc_plugin b/GNUmakefile.gcc_plugin
index 17bd825d..28a1a828 100644
--- a/GNUmakefile.gcc_plugin
+++ b/GNUmakefile.gcc_plugin
@@ -28,14 +28,14 @@ MAN_PATH    ?= $(PREFIX)/share/man/man8
 
 VERSION     = $(shell grep '^$(HASH)define VERSION ' ./config.h | cut -d '"' -f2)
 
-CFLAGS          ?= -O3 -g -funroll-loops -D_FORTIFY_SOURCE=2
+CFLAGS          ?= -O3 -g -funroll-loops -D_FORTIFY_SOURCE=1
 CFLAGS_SAFE     := -Wall -Iinclude -Wno-pointer-sign \
                    -DAFL_PATH=\"$(HELPER_PATH)\" -DBIN_PATH=\"$(BIN_PATH)\" \
                    -DGCC_VERSION=\"$(GCCVER)\" -DGCC_BINDIR=\"$(GCCBINDIR)\" \
                    -Wno-unused-function
 override CFLAGS += $(CFLAGS_SAFE)
 
-CXXFLAGS    ?= -O3 -g -funroll-loops -D_FORTIFY_SOURCE=2
+CXXFLAGS    ?= -O3 -g -funroll-loops -D_FORTIFY_SOURCE=1
 CXXEFLAGS   := $(CXXFLAGS) -Wall -std=c++11
 
 CC          ?= gcc
diff --git a/GNUmakefile.llvm b/GNUmakefile.llvm
index 7e090f69..d6e45d29 100644
--- a/GNUmakefile.llvm
+++ b/GNUmakefile.llvm
@@ -254,7 +254,7 @@ else
         AFL_CLANG_DEBUG_PREFIX =
 endif
 
-CFLAGS          ?= -O3 -funroll-loops -fPIC -D_FORTIFY_SOURCE=2
+CFLAGS          ?= -O3 -funroll-loops -fPIC -D_FORTIFY_SOURCE=1
 CFLAGS_SAFE     := -Wall -g -Wno-cast-qual -Wno-variadic-macros -Wno-pointer-sign \
                    -I ./include/ -I ./instrumentation/ \
                    -DAFL_PATH=\"$(HELPER_PATH)\" -DBIN_PATH=\"$(BIN_PATH)\" \
@@ -274,9 +274,9 @@ ifdef AFL_TRACE_PC
   $(info Compile option AFL_TRACE_PC is deprecated, just set AFL_LLVM_INSTRUMENT=PCGUARD to activate when compiling targets )
 endif
 
-CXXFLAGS          ?= -O3 -funroll-loops -fPIC -D_FORTIFY_SOURCE=2
+CXXFLAGS          ?= -O3 -funroll-loops -fPIC -D_FORTIFY_SOURCE=1
 override CXXFLAGS += -Wall -g -I ./include/ \
-                     -DVERSION=\"$(VERSION)\" -Wno-variadic-macros \
+                     -DVERSION=\"$(VERSION)\" -Wno-variadic-macros -Wno-deprecated-copy-with-dtor \
                      -DLLVM_MINOR=$(LLVM_MINOR) -DLLVM_MAJOR=$(LLVM_MAJOR)
 
 ifneq "$(shell $(LLVM_CONFIG) --includedir) 2> /dev/null" ""
diff --git a/TODO.md b/TODO.md
index 99d2c419..862224f0 100644
--- a/TODO.md
+++ b/TODO.md
@@ -2,12 +2,14 @@
 
 ## Should
 
- - better documentation for custom mutators
+ - support afl_custom_{send,post_process}, persistent and deferred fork
+   server in afl-showmap
  - better autodetection of shifting runtime timeout values
  - Update afl->pending_not_fuzzed for MOpt
  - afl-plot to support multiple plot_data
  - parallel builds for source-only targets
  - get rid of check_binary, replace with more forkserver communication
+ - first fuzzer should be a main automatically
 
 ## Maybe
 
diff --git a/docs/Changelog.md b/docs/Changelog.md
index c5eb6be3..4df47645 100644
--- a/docs/Changelog.md
+++ b/docs/Changelog.md
@@ -9,6 +9,9 @@
       send fuzz data to the target as you need, e.g. via IPC.
     - cmplog mode now has -l R option for random colorization, thanks
       to guyf2010 for the PR!
+    - queue statistics are written every 30 minutes to
+      out/NAME/queue_data - likely this will be moved to a debug flag
+      in the future.
   - afl-showmap/afl-cmin
     - -t none now translates to -t 120000 (120 seconds)
   - unicorn_mode updated
diff --git a/docs/env_variables.md b/docs/env_variables.md
index d1c13e15..22a5c386 100644
--- a/docs/env_variables.md
+++ b/docs/env_variables.md
@@ -378,10 +378,10 @@ checks or alter some of the more exotic semantics of the tool:
     valid terminal was detected (for virtual consoles).
 
   - Setting `AFL_FORKSRV_INIT_TMOUT` allows you to specify a different timeout
-    to wait for the forkserver to spin up. The default is the `-t` value times
-    `FORK_WAIT_MULT` from `config.h` (usually 10), so for a `-t 100`, the
-    default would wait for `1000` milliseconds. Setting a different time here is
-    useful if the target has a very slow startup time, for example, when doing
+    to wait for the forkserver to spin up. The specified value is the new timeout, in milliseconds.
+    The default is the `-t` value times `FORK_WAIT_MULT` from `config.h` (usually 10), so for a `-t 100`, the default would wait for `1000` milliseconds.
+    The `AFL_FORKSRV_INIT_TMOUT` value does not get multiplied. It overwrites the initial timeout afl-fuzz waits for the target to come up with a constant time.
+    Setting a different time here is useful if the target has a very slow startup time, for example, when doing
     full-system fuzzing or emulation, but you don't want the actual runs to wait
     too long for timeouts.
 
diff --git a/docs/fuzzing_in_depth.md b/docs/fuzzing_in_depth.md
index a0bf1566..87f31a58 100644
--- a/docs/fuzzing_in_depth.md
+++ b/docs/fuzzing_in_depth.md
@@ -900,6 +900,13 @@ then color-codes the input based on which sections appear to be critical and
 which are not; while not bulletproof, it can often offer quick insights into
 complex file formats.
 
+`casr-afl` from [CASR](https://github.com/ispras/casr) tools provides
+comfortable triaging for crashes found by AFL++. Reports are clustered and
+contain severity and other information.
+```shell
+casr-afl -i /path/to/afl/out/dir -o /path/to/casr/out/dir
+```
+
 ## 5. CI fuzzing
 
 Some notes on continuous integration (CI) fuzzing - this fuzzing is different to
diff --git a/docs/third_party_tools.md b/docs/third_party_tools.md
index 1175d9e5..97f2c362 100644
--- a/docs/third_party_tools.md
+++ b/docs/third_party_tools.md
@@ -62,3 +62,5 @@
   generates builds of debian packages suitable for AFL.
 * [afl-fid](https://github.com/FoRTE-Research/afl-fid) - a set of tools for
   working with input data.
+* [CASR](https://github.com/ispras/casr) - a set of tools for crash triage and
+  analysis.
diff --git a/frida_mode/GNUmakefile b/frida_mode/GNUmakefile
index 9f2bcd42..d283c3d7 100644
--- a/frida_mode/GNUmakefile
+++ b/frida_mode/GNUmakefile
@@ -145,7 +145,7 @@ ifndef OS
  $(error "Operating system unsupported")
 endif
 
-GUM_DEVKIT_VERSION=16.0.1
+GUM_DEVKIT_VERSION=16.0.6
 GUM_DEVKIT_FILENAME=frida-gumjs-devkit-$(GUM_DEVKIT_VERSION)-$(OS)-$(ARCH).tar.xz
 GUM_DEVKIT_URL="https://github.com/frida/frida/releases/download/$(GUM_DEVKIT_VERSION)/$(GUM_DEVKIT_FILENAME)"
 
@@ -191,6 +191,9 @@ all: $(FRIDA_TRACE) $(FRIDA_TRACE_LIB) $(AFLPP_FRIDA_DRIVER_HOOK_OBJ) $(AFLPP_QE
 32:
 	CFLAGS="-m32" LDFLAGS="-m32" ARCH="x86" make all
 
+arm:
+	CFLAGS="-marm" LDFLAGS="-marm" ARCH="armhf" TARGET_CC=arm-linux-gnueabihf-gcc TARGET_CXX=arm-linux-gnueabihf-g++ make all
+
 $(BUILD_DIR):
 	mkdir -p $(BUILD_DIR)
 
diff --git a/frida_mode/src/cmplog/cmplog_arm64.c b/frida_mode/src/cmplog/cmplog_arm64.c
index 5792cbfa..095dc242 100644
--- a/frida_mode/src/cmplog/cmplog_arm64.c
+++ b/frida_mode/src/cmplog/cmplog_arm64.c
@@ -204,10 +204,7 @@ static void cmplog_handle_cmp_sub(GumCpuContext *context, gsize operand1,
 
   gsize address = context->pc;
 
-  register uintptr_t k = (uintptr_t)address;
-
-  k = (k >> 4) ^ (k << 8);
-  k &= CMP_MAP_W - 1;
+  register uintptr_t k = instrument_get_offset_hash(GUM_ADDRESS(address));
 
   if (__afl_cmp_map->headers[k].type != CMP_TYPE_INS)
     __afl_cmp_map->headers[k].hits = 0;
diff --git a/frida_mode/src/cmplog/cmplog_x64.c b/frida_mode/src/cmplog/cmplog_x64.c
index 17912648..ce6b8681 100644
--- a/frida_mode/src/cmplog/cmplog_x64.c
+++ b/frida_mode/src/cmplog/cmplog_x64.c
@@ -188,10 +188,7 @@ static void cmplog_handle_cmp_sub(GumCpuContext *context, gsize operand1,
 
   gsize address = ctx_read_reg(context, X86_REG_RIP);
 
-  register uintptr_t k = (uintptr_t)address;
-
-  k = (k >> 4) ^ (k << 8);
-  k &= CMP_MAP_W - 7;
+  register uintptr_t k = instrument_get_offset_hash(GUM_ADDRESS(address));
 
   if (__afl_cmp_map->headers[k].type != CMP_TYPE_INS)
     __afl_cmp_map->headers[k].hits = 0;
diff --git a/frida_mode/src/cmplog/cmplog_x86.c b/frida_mode/src/cmplog/cmplog_x86.c
index a3a02457..fa06d611 100644
--- a/frida_mode/src/cmplog/cmplog_x86.c
+++ b/frida_mode/src/cmplog/cmplog_x86.c
@@ -193,10 +193,7 @@ static void cmplog_handle_cmp_sub(GumCpuContext *context, gsize operand1,
 
   gsize address = ctx_read_reg(context, X86_REG_EIP);
 
-  register uintptr_t k = (uintptr_t)address;
-
-  k = (k >> 4) ^ (k << 8);
-  k &= CMP_MAP_W - 1;
+  register uintptr_t k = instrument_get_offset_hash(GUM_ADDRESS(address));
 
   if (__afl_cmp_map->headers[k].type != CMP_TYPE_INS)
     __afl_cmp_map->headers[k].hits = 0;
diff --git a/frida_mode/src/instrument/instrument_arm32.c b/frida_mode/src/instrument/instrument_arm32.c
index cb2a322b..51f78a35 100644
--- a/frida_mode/src/instrument/instrument_arm32.c
+++ b/frida_mode/src/instrument/instrument_arm32.c
@@ -273,7 +273,19 @@ void instrument_flush(GumStalkerOutput *output) {
 
 gpointer instrument_cur(GumStalkerOutput *output) {
 
-  return gum_arm_writer_cur(output->writer.arm);
+  gpointer curr = NULL;
+
+  if (output->encoding == GUM_INSTRUCTION_SPECIAL) {
+
+    curr = gum_thumb_writer_cur(output->writer.thumb);
+
+  } else {
+
+    curr = gum_arm_writer_cur(output->writer.arm);
+
+  }
+
+  return curr;
 
 }
 
diff --git a/frida_mode/src/instrument/instrument_arm64.c b/frida_mode/src/instrument/instrument_arm64.c
index c7584a87..39e32b12 100644
--- a/frida_mode/src/instrument/instrument_arm64.c
+++ b/frida_mode/src/instrument/instrument_arm64.c
@@ -196,7 +196,7 @@ static void instrument_coverage_switch(GumStalkerObserver *self,
   insn = instrument_disassemble(from_insn);
   deterministic = instrument_is_deterministic(insn);
   cs_free(insn, 1);
-  if (deterministic) { return; }
+  if (!deterministic) { return; }
 
   /*
    * Since each block is prefixed with a restoration prologue, we need to be
diff --git a/frida_mode/test/png/GNUmakefile b/frida_mode/test/png/GNUmakefile
index 864265e0..86fd1483 100644
--- a/frida_mode/test/png/GNUmakefile
+++ b/frida_mode/test/png/GNUmakefile
@@ -7,10 +7,10 @@ LIBPNG_BUILD_DIR:=$(BUILD_DIR)libpng/
 HARNESS_BUILD_DIR:=$(BUILD_DIR)harness/
 PNGTEST_BUILD_DIR:=$(BUILD_DIR)pngtest/
 
-LIBZ_FILE:=$(LIBZ_BUILD_DIR)zlib-1.2.12.tar.gz
-LIBZ_URL:=http://www.zlib.net/zlib-1.2.12.tar.gz
-LIBZ_DIR:=$(LIBZ_BUILD_DIR)zlib-1.2.12/
-LIBZ_PC:=$(ZLIB_DIR)zlib.pc
+LIBZ_FILE:=$(LIBZ_BUILD_DIR)zlib-1.2.13.tar.gz
+LIBZ_URL:=http://www.zlib.net/zlib-1.2.13.tar.gz
+LIBZ_DIR:=$(LIBZ_BUILD_DIR)zlib-1.2.13/
+LIBZ_PC:=$(LIBZ_DIR)zlib.pc
 LIBZ_LIB:=$(LIBZ_DIR)libz.a
 
 LIBPNG_FILE:=$(LIBPNG_BUILD_DIR)libpng-1.2.56.tar.gz
@@ -48,7 +48,7 @@ all: $(TEST_BIN)
 	CFLAGS="-m32" LDFLAGS="-m32" make $(TEST_BIN)
 
 arm:
-	ARCH="arm" CC="arm-linux-gnueabihf-gcc" CXX="arm-linux-gnueabihf-g++" make $(TEST_BIN)
+	CFLAGS="-marm" LDFLAGS="-marm" CC="arm-linux-gnueabihf-gcc" CXX="arm-linux-gnueabihf-g++" make $(TEST_BIN)
 
 $(BUILD_DIR):
 	mkdir -p $@
@@ -96,7 +96,7 @@ $(LIBZ_PC): | $(LIBZ_DIR)
 			--static \
 			--archs="$(ARCH)"
 
-$(LIBZ_LIB): $(LIBZ_PC)
+$(LIBZ_LIB): | $(LIBZ_PC)
 	CFLAGS="$(CFLAGS) -fPIC" \
 		make \
 			-C $(LIBZ_DIR) \
@@ -133,7 +133,7 @@ png: $(LIBPNG_LIB)
 
 ######### TEST ########
 
-$(TEST_BIN): $(HARNESS_OBJ) $(PNGTEST_OBJ) $(LIBPNG_LIB)
+$(TEST_BIN): $(HARNESS_OBJ) $(PNGTEST_OBJ) $(LIBPNG_LIB) $(LIBZ_LIB)
 	$(CXX) \
 		$(CFLAGS) \
 		$(LDFLAGS) \
diff --git a/frida_mode/test/testinstr/GNUmakefile b/frida_mode/test/testinstr/GNUmakefile
index 79eee213..ebc0b2dc 100644
--- a/frida_mode/test/testinstr/GNUmakefile
+++ b/frida_mode/test/testinstr/GNUmakefile
@@ -18,6 +18,9 @@ all: $(TESTINSTBIN)
 32:
 	CFLAGS="-m32" LDFLAGS="-m32" ARCH="x86" make all
 
+arm:
+	CFLAGS="-marm" LDFLAGS="-marm" CC="arm-linux-gnueabihf-gcc" CXX="arm-linux-gnueabihf-g++" make $(TESTINSTBIN)
+
 $(BUILD_DIR):
 	mkdir -p $@
 
diff --git a/include/afl-fuzz.h b/include/afl-fuzz.h
index 88646db3..ea83aaca 100644
--- a/include/afl-fuzz.h
+++ b/include/afl-fuzz.h
@@ -169,12 +169,22 @@ struct queue_entry {
 
   u32 bitmap_size,                      /* Number of bits set in bitmap     */
       fuzz_level,                       /* Number of fuzzing iterations     */
-      n_fuzz_entry;                     /* offset in n_fuzz                 */
+      n_fuzz_entry                      /* offset in n_fuzz                 */
+#ifdef INTROSPECTION
+      ,
+      stats_selected,                   /* stats: how often selected        */
+      stats_skipped,                    /* stats: how often skipped         */
+      stats_finds,                      /* stats: # of saved finds          */
+      stats_crashes,                    /* stats: # of saved crashes        */
+      stats_tmouts                      /* stats: # of saved timeouts       */
+#endif
+      ;
 
   u64 exec_us,                          /* Execution time (us)              */
       handicap,                         /* Number of queue cycles behind    */
       depth,                            /* Path depth                       */
-      exec_cksum;                       /* Checksum of the execution trace  */
+      exec_cksum,                       /* Checksum of the execution trace  */
+      stats_mutated;                    /* stats: # of mutations performed  */
 
   u8 *trace_mini;                       /* Trace bytes, if kept             */
   u32 tc_ref;                           /* Trace bytes ref count            */
@@ -686,7 +696,8 @@ typedef struct afl_state {
   u32 plot_prev_qp, plot_prev_pf, plot_prev_pnf, plot_prev_ce, plot_prev_md;
   u64 plot_prev_qc, plot_prev_uc, plot_prev_uh, plot_prev_ed;
 
-  u64 stats_last_stats_ms, stats_last_plot_ms, stats_last_ms, stats_last_execs;
+  u64 stats_last_stats_ms, stats_last_plot_ms, stats_last_queue_ms,
+      stats_last_ms, stats_last_execs;
 
   /* StatsD */
   u64                statsd_last_send_ms;
@@ -1101,6 +1112,7 @@ void load_stats_file(afl_state_t *);
 void write_setup_file(afl_state_t *, u32, char **);
 void write_stats_file(afl_state_t *, u32, double, double, double);
 void maybe_update_plot_file(afl_state_t *, u32, double, double);
+void write_queue_stats(afl_state_t *);
 void show_stats(afl_state_t *);
 void show_stats_normal(afl_state_t *);
 void show_stats_pizza(afl_state_t *);
diff --git a/include/config.h b/include/config.h
index 22c1a162..b82ead47 100644
--- a/include/config.h
+++ b/include/config.h
@@ -290,10 +290,11 @@
 
 #define UI_TARGET_HZ 5
 
-/* Fuzzer stats file and plot update intervals (sec): */
+/* Fuzzer stats file, queue stats and plot update intervals (sec): */
 
 #define STATS_UPDATE_SEC 60
 #define PLOT_UPDATE_SEC 5
+#define QUEUE_UPDATE_SEC 1800
 
 /* Smoothing divisor for CPU load and exec speed stats (1 - no smoothing). */
 
diff --git a/include/envs.h b/include/envs.h
index 68d83f8c..f4cdf390 100644
--- a/include/envs.h
+++ b/include/envs.h
@@ -124,7 +124,9 @@ static char *afl_environment_variables[] = {
     "AFL_LLVM_ALLOWLIST",
     "AFL_LLVM_DENYLIST",
     "AFL_LLVM_BLOCKLIST",
+    "AFL_CMPLOG",
     "AFL_LLVM_CMPLOG",
+    "AFL_GCC_CMPLOG",
     "AFL_LLVM_INSTRIM",
     "AFL_LLVM_CALLER",
     "AFL_LLVM_CTX",
diff --git a/qemu_mode/QEMUAFL_VERSION b/qemu_mode/QEMUAFL_VERSION
index 8d384d31..9c68f02c 100644
--- a/qemu_mode/QEMUAFL_VERSION
+++ b/qemu_mode/QEMUAFL_VERSION
@@ -1 +1 @@
-fa07ebfff5
+a8af9cbde7
diff --git a/qemu_mode/qemuafl b/qemu_mode/qemuafl
-Subproject fa07ebfff5de3d7a531caf2f9e0306960953a5e
+Subproject a8af9cbde71e333ce72a46f15e655d0b82ed093
diff --git a/src/afl-fuzz-init.c b/src/afl-fuzz-init.c
index e41d29fd..ed52ca00 100644
--- a/src/afl-fuzz-init.c
+++ b/src/afl-fuzz-init.c
@@ -1848,6 +1848,10 @@ static void handle_existing_out_dir(afl_state_t *afl) {
 
   }
 
+  fn = alloc_printf("%s/queue_data", afl->out_dir);
+  if (unlink(fn) && errno != ENOENT) { goto dir_cleanup_failed; }
+  ck_free(fn);
+
   fn = alloc_printf("%s/cmdline", afl->out_dir);
   if (unlink(fn) && errno != ENOENT) { goto dir_cleanup_failed; }
   ck_free(fn);
diff --git a/src/afl-fuzz-one.c b/src/afl-fuzz-one.c
index ed9e7a81..9931820a 100644
--- a/src/afl-fuzz-one.c
+++ b/src/afl-fuzz-one.c
@@ -743,6 +743,9 @@ u8 fuzz_one_original(afl_state_t *afl) {
 
   afl->stage_finds[STAGE_FLIP1] += new_hit_cnt - orig_hit_cnt;
   afl->stage_cycles[STAGE_FLIP1] += afl->stage_max;
+#ifdef INTROSPECTION
+  afl->queue_cur->stats_mutated += afl->stage_max;
+#endif
 
   /* Two walking bits. */
 
@@ -775,6 +778,9 @@ u8 fuzz_one_original(afl_state_t *afl) {
 
   afl->stage_finds[STAGE_FLIP2] += new_hit_cnt - orig_hit_cnt;
   afl->stage_cycles[STAGE_FLIP2] += afl->stage_max;
+#ifdef INTROSPECTION
+  afl->queue_cur->stats_mutated += afl->stage_max;
+#endif
 
   /* Four walking bits. */
 
@@ -811,6 +817,9 @@ u8 fuzz_one_original(afl_state_t *afl) {
 
   afl->stage_finds[STAGE_FLIP4] += new_hit_cnt - orig_hit_cnt;
   afl->stage_cycles[STAGE_FLIP4] += afl->stage_max;
+#ifdef INTROSPECTION
+  afl->queue_cur->stats_mutated += afl->stage_max;
+#endif
 
   /* Effector map setup. These macros calculate:
 
@@ -919,6 +928,9 @@ u8 fuzz_one_original(afl_state_t *afl) {
 
   afl->stage_finds[STAGE_FLIP8] += new_hit_cnt - orig_hit_cnt;
   afl->stage_cycles[STAGE_FLIP8] += afl->stage_max;
+#ifdef INTROSPECTION
+  afl->queue_cur->stats_mutated += afl->stage_max;
+#endif
 
   /* Two walking bytes. */
 
@@ -962,6 +974,9 @@ u8 fuzz_one_original(afl_state_t *afl) {
 
   afl->stage_finds[STAGE_FLIP16] += new_hit_cnt - orig_hit_cnt;
   afl->stage_cycles[STAGE_FLIP16] += afl->stage_max;
+#ifdef INTROSPECTION
+  afl->queue_cur->stats_mutated += afl->stage_max;
+#endif
 
   if (len < 4) { goto skip_bitflip; }
 
@@ -1005,6 +1020,9 @@ u8 fuzz_one_original(afl_state_t *afl) {
 
   afl->stage_finds[STAGE_FLIP32] += new_hit_cnt - orig_hit_cnt;
   afl->stage_cycles[STAGE_FLIP32] += afl->stage_max;
+#ifdef INTROSPECTION
+  afl->queue_cur->stats_mutated += afl->stage_max;
+#endif
 
 skip_bitflip:
 
@@ -1097,6 +1115,9 @@ skip_bitflip:
 
   afl->stage_finds[STAGE_ARITH8] += new_hit_cnt - orig_hit_cnt;
   afl->stage_cycles[STAGE_ARITH8] += afl->stage_max;
+#ifdef INTROSPECTION
+  afl->queue_cur->stats_mutated += afl->stage_max;
+#endif
 
   /* 16-bit arithmetics, both endians. */
 
@@ -1227,6 +1248,9 @@ skip_bitflip:
 
   afl->stage_finds[STAGE_ARITH16] += new_hit_cnt - orig_hit_cnt;
   afl->stage_cycles[STAGE_ARITH16] += afl->stage_max;
+#ifdef INTROSPECTION
+  afl->queue_cur->stats_mutated += afl->stage_max;
+#endif
 
   /* 32-bit arithmetics, both endians. */
 
@@ -1356,6 +1380,9 @@ skip_bitflip:
 
   afl->stage_finds[STAGE_ARITH32] += new_hit_cnt - orig_hit_cnt;
   afl->stage_cycles[STAGE_ARITH32] += afl->stage_max;
+#ifdef INTROSPECTION
+  afl->queue_cur->stats_mutated += afl->stage_max;
+#endif
 
 skip_arith:
 
@@ -1422,6 +1449,9 @@ skip_arith:
 
   afl->stage_finds[STAGE_INTEREST8] += new_hit_cnt - orig_hit_cnt;
   afl->stage_cycles[STAGE_INTEREST8] += afl->stage_max;
+#ifdef INTROSPECTION
+  afl->queue_cur->stats_mutated += afl->stage_max;
+#endif
 
   /* Setting 16-bit integers, both endians. */
 
@@ -1510,6 +1540,9 @@ skip_arith:
 
   afl->stage_finds[STAGE_INTEREST16] += new_hit_cnt - orig_hit_cnt;
   afl->stage_cycles[STAGE_INTEREST16] += afl->stage_max;
+#ifdef INTROSPECTION
+  afl->queue_cur->stats_mutated += afl->stage_max;
+#endif
 
   if (len < 4) { goto skip_interest; }
 
@@ -1599,6 +1632,9 @@ skip_arith:
 
   afl->stage_finds[STAGE_INTEREST32] += new_hit_cnt - orig_hit_cnt;
   afl->stage_cycles[STAGE_INTEREST32] += afl->stage_max;
+#ifdef INTROSPECTION
+  afl->queue_cur->stats_mutated += afl->stage_max;
+#endif
 
 skip_interest:
 
@@ -1672,6 +1708,9 @@ skip_interest:
 
   afl->stage_finds[STAGE_EXTRAS_UO] += new_hit_cnt - orig_hit_cnt;
   afl->stage_cycles[STAGE_EXTRAS_UO] += afl->stage_max;
+#ifdef INTROSPECTION
+  afl->queue_cur->stats_mutated += afl->stage_max;
+#endif
 
   /* Insertion of user-supplied extras. */
 
@@ -1728,6 +1767,9 @@ skip_interest:
 
   afl->stage_finds[STAGE_EXTRAS_UI] += new_hit_cnt - orig_hit_cnt;
   afl->stage_cycles[STAGE_EXTRAS_UI] += afl->stage_max;
+#ifdef INTROSPECTION
+  afl->queue_cur->stats_mutated += afl->stage_max;
+#endif
 
 skip_user_extras:
 
@@ -1786,6 +1828,9 @@ skip_user_extras:
 
   afl->stage_finds[STAGE_EXTRAS_AO] += new_hit_cnt - orig_hit_cnt;
   afl->stage_cycles[STAGE_EXTRAS_AO] += afl->stage_max;
+#ifdef INTROSPECTION
+  afl->queue_cur->stats_mutated += afl->stage_max;
+#endif
 
   /* Insertion of auto extras. */
 
@@ -1842,6 +1887,9 @@ skip_user_extras:
 
   afl->stage_finds[STAGE_EXTRAS_AI] += new_hit_cnt - orig_hit_cnt;
   afl->stage_cycles[STAGE_EXTRAS_AI] += afl->stage_max;
+#ifdef INTROSPECTION
+  afl->queue_cur->stats_mutated += afl->stage_max;
+#endif
 
 skip_extras:
 
@@ -1988,6 +2036,9 @@ custom_mutator_stage:
 
   afl->stage_finds[STAGE_CUSTOM_MUTATOR] += new_hit_cnt - orig_hit_cnt;
   afl->stage_cycles[STAGE_CUSTOM_MUTATOR] += afl->stage_max;
+#ifdef INTROSPECTION
+  afl->queue_cur->stats_mutated += afl->stage_max;
+#endif
 
   if (likely(afl->custom_only)) {
 
@@ -2925,11 +2976,17 @@ havoc_stage:
 
     afl->stage_finds[STAGE_HAVOC] += new_hit_cnt - orig_hit_cnt;
     afl->stage_cycles[STAGE_HAVOC] += afl->stage_max;
+#ifdef INTROSPECTION
+    afl->queue_cur->stats_mutated += afl->stage_max;
+#endif
 
   } else {
 
     afl->stage_finds[STAGE_SPLICE] += new_hit_cnt - orig_hit_cnt;
     afl->stage_cycles[STAGE_SPLICE] += afl->stage_max;
+#ifdef INTROSPECTION
+    afl->queue_cur->stats_mutated += afl->stage_max;
+#endif
 
   }
 
@@ -3411,6 +3468,9 @@ static u8 mopt_common_fuzzing(afl_state_t *afl, MOpt_globals_t MOpt_globals) {
 
   afl->stage_finds[STAGE_FLIP1] += new_hit_cnt - orig_hit_cnt;
   afl->stage_cycles[STAGE_FLIP1] += afl->stage_max;
+#ifdef INTROSPECTION
+  afl->queue_cur->stats_mutated += afl->stage_max;
+#endif
 
   /* Two walking bits. */
 
@@ -3442,6 +3502,9 @@ static u8 mopt_common_fuzzing(afl_state_t *afl, MOpt_globals_t MOpt_globals) {
 
   afl->stage_finds[STAGE_FLIP2] += new_hit_cnt - orig_hit_cnt;
   afl->stage_cycles[STAGE_FLIP2] += afl->stage_max;
+#ifdef INTROSPECTION
+  afl->queue_cur->stats_mutated += afl->stage_max;
+#endif
 
   /* Four walking bits. */
 
@@ -3477,6 +3540,9 @@ static u8 mopt_common_fuzzing(afl_state_t *afl, MOpt_globals_t MOpt_globals) {
 
   afl->stage_finds[STAGE_FLIP4] += new_hit_cnt - orig_hit_cnt;
   afl->stage_cycles[STAGE_FLIP4] += afl->stage_max;
+#ifdef INTROSPECTION
+  afl->queue_cur->stats_mutated += afl->stage_max;
+#endif
 
   /* Effector map setup. These macros calculate:
 
@@ -3584,6 +3650,9 @@ static u8 mopt_common_fuzzing(afl_state_t *afl, MOpt_globals_t MOpt_globals) {
 
   afl->stage_finds[STAGE_FLIP8] += new_hit_cnt - orig_hit_cnt;
   afl->stage_cycles[STAGE_FLIP8] += afl->stage_max;
+#ifdef INTROSPECTION
+  afl->queue_cur->stats_mutated += afl->stage_max;
+#endif
 
   /* Two walking bytes. */
 
@@ -3626,6 +3695,9 @@ static u8 mopt_common_fuzzing(afl_state_t *afl, MOpt_globals_t MOpt_globals) {
 
   afl->stage_finds[STAGE_FLIP16] += new_hit_cnt - orig_hit_cnt;
   afl->stage_cycles[STAGE_FLIP16] += afl->stage_max;
+#ifdef INTROSPECTION
+  afl->queue_cur->stats_mutated += afl->stage_max;
+#endif
 
   if (len < 4) { goto skip_bitflip; }
 
@@ -3668,6 +3740,9 @@ static u8 mopt_common_fuzzing(afl_state_t *afl, MOpt_globals_t MOpt_globals) {
 
   afl->stage_finds[STAGE_FLIP32] += new_hit_cnt - orig_hit_cnt;
   afl->stage_cycles[STAGE_FLIP32] += afl->stage_max;
+#ifdef INTROSPECTION
+  afl->queue_cur->stats_mutated += afl->stage_max;
+#endif
 
 skip_bitflip:
 
@@ -3758,6 +3833,9 @@ skip_bitflip:
 
   afl->stage_finds[STAGE_ARITH8] += new_hit_cnt - orig_hit_cnt;
   afl->stage_cycles[STAGE_ARITH8] += afl->stage_max;
+#ifdef INTROSPECTION
+  afl->queue_cur->stats_mutated += afl->stage_max;
+#endif
 
   /* 16-bit arithmetics, both endians. */
 
@@ -3884,6 +3962,9 @@ skip_bitflip:
 
   afl->stage_finds[STAGE_ARITH16] += new_hit_cnt - orig_hit_cnt;
   afl->stage_cycles[STAGE_ARITH16] += afl->stage_max;
+#ifdef INTROSPECTION
+  afl->queue_cur->stats_mutated += afl->stage_max;
+#endif
 
   /* 32-bit arithmetics, both endians. */
 
@@ -4009,6 +4090,9 @@ skip_bitflip:
 
   afl->stage_finds[STAGE_ARITH32] += new_hit_cnt - orig_hit_cnt;
   afl->stage_cycles[STAGE_ARITH32] += afl->stage_max;
+#ifdef INTROSPECTION
+  afl->queue_cur->stats_mutated += afl->stage_max;
+#endif
 
 skip_arith:
 
@@ -4074,6 +4158,9 @@ skip_arith:
 
   afl->stage_finds[STAGE_INTEREST8] += new_hit_cnt - orig_hit_cnt;
   afl->stage_cycles[STAGE_INTEREST8] += afl->stage_max;
+#ifdef INTROSPECTION
+  afl->queue_cur->stats_mutated += afl->stage_max;
+#endif
 
   /* Setting 16-bit integers, both endians. */
 
@@ -4160,6 +4247,9 @@ skip_arith:
 
   afl->stage_finds[STAGE_INTEREST16] += new_hit_cnt - orig_hit_cnt;
   afl->stage_cycles[STAGE_INTEREST16] += afl->stage_max;
+#ifdef INTROSPECTION
+  afl->queue_cur->stats_mutated += afl->stage_max;
+#endif
 
   if (len < 4) { goto skip_interest; }
 
@@ -4247,6 +4337,9 @@ skip_arith:
 
   afl->stage_finds[STAGE_INTEREST32] += new_hit_cnt - orig_hit_cnt;
   afl->stage_cycles[STAGE_INTEREST32] += afl->stage_max;
+#ifdef INTROSPECTION
+  afl->queue_cur->stats_mutated += afl->stage_max;
+#endif
 
 skip_interest:
 
@@ -4320,6 +4413,9 @@ skip_interest:
 
   afl->stage_finds[STAGE_EXTRAS_UO] += new_hit_cnt - orig_hit_cnt;
   afl->stage_cycles[STAGE_EXTRAS_UO] += afl->stage_max;
+#ifdef INTROSPECTION
+  afl->queue_cur->stats_mutated += afl->stage_max;
+#endif
 
   /* Insertion of user-supplied extras. */
 
@@ -4376,6 +4472,9 @@ skip_interest:
 
   afl->stage_finds[STAGE_EXTRAS_UI] += new_hit_cnt - orig_hit_cnt;
   afl->stage_cycles[STAGE_EXTRAS_UI] += afl->stage_max;
+#ifdef INTROSPECTION
+  afl->queue_cur->stats_mutated += afl->stage_max;
+#endif
 
 skip_user_extras:
 
@@ -4435,6 +4534,9 @@ skip_user_extras:
 
   afl->stage_finds[STAGE_EXTRAS_AO] += new_hit_cnt - orig_hit_cnt;
   afl->stage_cycles[STAGE_EXTRAS_AO] += afl->stage_max;
+#ifdef INTROSPECTION
+  afl->queue_cur->stats_mutated += afl->stage_max;
+#endif
 
   /* Insertion of auto extras. */
 
@@ -4491,6 +4593,9 @@ skip_user_extras:
 
   afl->stage_finds[STAGE_EXTRAS_AI] += new_hit_cnt - orig_hit_cnt;
   afl->stage_cycles[STAGE_EXTRAS_AI] += afl->stage_max;
+#ifdef INTROSPECTION
+  afl->queue_cur->stats_mutated += afl->stage_max;
+#endif
 
 skip_extras:
 
@@ -5316,11 +5421,17 @@ pacemaker_fuzzing:
 
           afl->stage_finds[STAGE_HAVOC] += new_hit_cnt - orig_hit_cnt;
           afl->stage_cycles[STAGE_HAVOC] += afl->stage_max;
+#ifdef INTROSPECTION
+          afl->queue_cur->stats_mutated += afl->stage_max;
+#endif
 
         } else {
 
           afl->stage_finds[STAGE_SPLICE] += new_hit_cnt - orig_hit_cnt;
           afl->stage_cycles[STAGE_SPLICE] += afl->stage_max;
+#ifdef INTROSPECTION
+          afl->queue_cur->stats_mutated += afl->stage_max;
+#endif
 
         }
 
diff --git a/src/afl-fuzz-stats.c b/src/afl-fuzz-stats.c
index 61956dc3..87e149de 100644
--- a/src/afl-fuzz-stats.c
+++ b/src/afl-fuzz-stats.c
@@ -365,6 +365,39 @@ void write_stats_file(afl_state_t *afl, u32 t_bytes, double bitmap_cvg,
 
 }
 
+#ifdef INTROSPECTION
+void write_queue_stats(afl_state_t *afl) {
+
+  FILE *f;
+  u8   *fn = alloc_printf("%s/queue_data", afl->out_dir);
+  if ((f = fopen(fn, "w")) != NULL) {
+
+    u32 id;
+    fprintf(f,
+            "# filename, length, exec_us, selected, skipped, mutations, finds, "
+            "crashes, timeouts, bitmap_size, perf_score, weight, colorized, "
+            "favored, disabled\n");
+    for (id = 0; id < afl->queued_items; ++id) {
+
+      struct queue_entry *q = afl->queue_buf[id];
+      fprintf(f, "\"%s\",%u,%llu,%u,%u,%llu,%u,%u,%u,%u,%.3f,%.3f,%u,%u,%u\n",
+              q->fname, q->len, q->exec_us, q->stats_selected, q->stats_skipped,
+              q->stats_mutated, q->stats_finds, q->stats_crashes,
+              q->stats_tmouts, q->bitmap_size, q->perf_score, q->weight,
+              q->colorized, q->favored, q->disabled);
+
+    }
+
+    fclose(f);
+
+  }
+
+  ck_free(fn);
+
+}
+
+#endif
+
 /* Update the plot file if there is a reason to. */
 
 void maybe_update_plot_file(afl_state_t *afl, u32 t_bytes, double bitmap_cvg,
@@ -613,6 +646,18 @@ void show_stats_normal(afl_state_t *afl) {
 
   }
 
+  /* Every now and then, write queue data. */
+
+  if (unlikely(afl->force_ui_update ||
+               cur_ms - afl->stats_last_queue_ms > QUEUE_UPDATE_SEC * 1000)) {
+
+    afl->stats_last_queue_ms = cur_ms;
+#ifdef INTROSPECTION
+    write_queue_stats(afl);
+#endif
+
+  }
+
   /* Honor AFL_EXIT_WHEN_DONE and AFL_BENCH_UNTIL_CRASH. */
 
   if (unlikely(!afl->non_instrumented_mode && afl->cycles_wo_finds > 100 &&
@@ -1399,6 +1444,18 @@ void show_stats_pizza(afl_state_t *afl) {
 
   }
 
+  /* Every now and then, write queue data. */
+
+  if (unlikely(afl->force_ui_update ||
+               cur_ms - afl->stats_last_queue_ms > QUEUE_UPDATE_SEC * 1000)) {
+
+    afl->stats_last_queue_ms = cur_ms;
+#ifdef INTROSPECTION
+    write_queue_stats(afl);
+#endif
+
+  }
+
   /* Honor AFL_EXIT_WHEN_DONE and AFL_BENCH_UNTIL_CRASH. */
 
   if (unlikely(!afl->non_instrumented_mode && afl->cycles_wo_finds > 100 &&
diff --git a/src/afl-fuzz.c b/src/afl-fuzz.c
index a81cab7d..efef5523 100644
--- a/src/afl-fuzz.c
+++ b/src/afl-fuzz.c
@@ -501,7 +501,7 @@ int main(int argc, char **argv_orig, char **envp) {
 
   s32 opt, auto_sync = 0 /*, user_set_cache = 0*/;
   u64 prev_queued = 0;
-  u32 sync_interval_cnt = 0, seek_to = 0, show_help = 0,
+  u32 sync_interval_cnt = 0, seek_to = 0, show_help = 0, default_output = 1,
       map_size = get_map_size();
   u8 *extras_dir[4];
   u8  mem_limit_given = 0, exit_1 = 0, debug = 0,
@@ -802,6 +802,7 @@ int main(int argc, char **argv_orig, char **envp) {
 
         afl->fsrv.out_file = ck_strdup(optarg);
         afl->fsrv.use_stdin = 0;
+        default_output = 0;
         break;
 
       case 'x':                                               /* dictionary */
@@ -1911,6 +1912,7 @@ int main(int argc, char **argv_orig, char **envp) {
       if (aa_loc && !afl->fsrv.out_file) {
 
         afl->fsrv.use_stdin = 0;
+        default_output = 0;
 
         if (afl->file_extension) {
 
@@ -2154,7 +2156,7 @@ int main(int argc, char **argv_orig, char **envp) {
 
     afl->fsrv.out_file = NULL;
     afl->fsrv.use_stdin = 0;
-    if (!afl->unicorn_mode && !afl->fsrv.use_stdin) {
+    if (!afl->unicorn_mode && !afl->fsrv.use_stdin && !default_output) {
 
       WARNF(
           "You specified -f or @@ on the command line but the target harness "
@@ -2277,8 +2279,10 @@ int main(int argc, char **argv_orig, char **envp) {
   // real start time, we reset, so this works correctly with -V
   afl->start_time = get_cur_time();
 
-  u32 runs_in_current_cycle = (u32)-1;
-  u32 prev_queued_items = 0;
+  #ifdef INTROSPECTION
+  u32 prev_saved_crashes = 0, prev_saved_tmouts = 0;
+  #endif
+  u32 prev_queued_items = 0, runs_in_current_cycle = (u32)-1;
   u8  skipped_fuzz;
 
   #ifdef INTROSPECTION
@@ -2306,6 +2310,12 @@ int main(int argc, char **argv_orig, char **envp) {
                     (!afl->queue_cycle && afl->afl_env.afl_import_first)) &&
                    afl->sync_id)) {
 
+        if (!afl->queue_cycle && afl->afl_env.afl_import_first) {
+
+          OKF("Syncing queues from other fuzzer instances first ...");
+
+        }
+
         sync_fuzzers(afl);
 
       }
@@ -2523,27 +2533,69 @@ int main(int argc, char **argv_orig, char **envp) {
 
         }
 
-        afl->current_entry = select_next_queue_entry(afl);
+        do {
+
+          afl->current_entry = select_next_queue_entry(afl);
+
+        } while (unlikely(afl->current_entry >= afl->queued_items));
+
         afl->queue_cur = afl->queue_buf[afl->current_entry];
 
       }
 
       skipped_fuzz = fuzz_one(afl);
+  #ifdef INTROSPECTION
+      ++afl->queue_cur->stats_selected;
+      if (unlikely(skipped_fuzz)) {
+
+        ++afl->queue_cur->stats_skipped;
+
+      } else {
+
+        if (unlikely(afl->queued_items > prev_queued_items)) {
+
+          afl->queue_cur->stats_finds += afl->queued_items - prev_queued_items;
+          prev_queued_items = afl->queued_items;
+
+        }
+
+        if (unlikely(afl->saved_crashes > prev_saved_crashes)) {
+
+          afl->queue_cur->stats_crashes +=
+              afl->saved_crashes - prev_saved_crashes;
+          prev_saved_crashes = afl->saved_crashes;
+
+        }
+
+        if (unlikely(afl->saved_tmouts > prev_saved_tmouts)) {
+
+          afl->queue_cur->stats_tmouts += afl->saved_tmouts - prev_saved_tmouts;
+          prev_saved_tmouts = afl->saved_tmouts;
+
+        }
+
+      }
+
+  #endif
 
       if (unlikely(!afl->stop_soon && exit_1)) { afl->stop_soon = 2; }
 
       if (unlikely(afl->old_seed_selection)) {
 
         while (++afl->current_entry < afl->queued_items &&
-               afl->queue_buf[afl->current_entry]->disabled)
-          ;
+               afl->queue_buf[afl->current_entry]->disabled) {};
         if (unlikely(afl->current_entry >= afl->queued_items ||
                      afl->queue_buf[afl->current_entry] == NULL ||
-                     afl->queue_buf[afl->current_entry]->disabled))
+                     afl->queue_buf[afl->current_entry]->disabled)) {
+
           afl->queue_cur = NULL;
-        else
+
+        } else {
+
           afl->queue_cur = afl->queue_buf[afl->current_entry];
 
+        }
+
       }
 
     } while (skipped_fuzz && afl->queue_cur && !afl->stop_soon);
diff --git a/src/afl-showmap.c b/src/afl-showmap.c
index 93339a8f..d85c28d9 100644
--- a/src/afl-showmap.c
+++ b/src/afl-showmap.c
@@ -1233,6 +1233,36 @@ int main(int argc, char **argv_orig, char **envp) {
 
   }
 
+  if (getenv("AFL_FORKSRV_INIT_TMOUT")) {
+
+    s32 forksrv_init_tmout = atoi(getenv("AFL_FORKSRV_INIT_TMOUT"));
+    if (forksrv_init_tmout < 1) {
+
+      FATAL("Bad value specified for AFL_FORKSRV_INIT_TMOUT");
+
+    }
+
+    fsrv->init_tmout = (u32)forksrv_init_tmout;
+
+  }
+
+  if (getenv("AFL_CRASH_EXITCODE")) {
+
+    long exitcode = strtol(getenv("AFL_CRASH_EXITCODE"), NULL, 10);
+    if ((!exitcode && (errno == EINVAL || errno == ERANGE)) ||
+        exitcode < -127 || exitcode > 128) {
+
+      FATAL("Invalid crash exitcode, expected -127 to 128, but got %s",
+            getenv("AFL_CRASH_EXITCODE"));
+
+    }
+
+    fsrv->uses_crash_exitcode = true;
+    // WEXITSTATUS is 8 bit unsigned
+    fsrv->crash_exitcode = (u8)exitcode;
+
+  }
+
   if (in_dir) { (void)check_binary_signatures(fsrv->target_path); }
 
   shm_fuzz = ck_alloc(sizeof(sharedmem_t));
@@ -1365,36 +1395,6 @@ int main(int argc, char **argv_orig, char **envp) {
 
     }
 
-    if (getenv("AFL_FORKSRV_INIT_TMOUT")) {
-
-      s32 forksrv_init_tmout = atoi(getenv("AFL_FORKSRV_INIT_TMOUT"));
-      if (forksrv_init_tmout < 1) {
-
-        FATAL("Bad value specified for AFL_FORKSRV_INIT_TMOUT");
-
-      }
-
-      fsrv->init_tmout = (u32)forksrv_init_tmout;
-
-    }
-
-    if (getenv("AFL_CRASH_EXITCODE")) {
-
-      long exitcode = strtol(getenv("AFL_CRASH_EXITCODE"), NULL, 10);
-      if ((!exitcode && (errno == EINVAL || errno == ERANGE)) ||
-          exitcode < -127 || exitcode > 128) {
-
-        FATAL("Invalid crash exitcode, expected -127 to 128, but got %s",
-              getenv("AFL_CRASH_EXITCODE"));
-
-      }
-
-      fsrv->uses_crash_exitcode = true;
-      // WEXITSTATUS is 8 bit unsigned
-      fsrv->crash_exitcode = (u8)exitcode;
-
-    }
-
     afl_fsrv_start(fsrv, use_argv, &stop_soon,
                    (get_afl_env("AFL_DEBUG_CHILD") ||
                     get_afl_env("AFL_DEBUG_CHILD_OUTPUT"))
diff --git a/utils/argv_fuzzing/argv-fuzz-inl.h b/utils/argv_fuzzing/argv-fuzz-inl.h
index c15c0271..ec22c53b 100644
--- a/utils/argv_fuzzing/argv-fuzz-inl.h
+++ b/utils/argv_fuzzing/argv-fuzz-inl.h
@@ -34,6 +34,7 @@
 #ifndef _HAVE_ARGV_FUZZ_INL
 #define _HAVE_ARGV_FUZZ_INL
 
+#include <stdlib.h>
 #include <unistd.h>
 
 #define AFL_INIT_ARGV()          \
@@ -63,7 +64,10 @@ static char **afl_init_argv(int *argc) {
   char *ptr = in_buf;
   int   rc = 0;
 
-  if (read(0, in_buf, MAX_CMDLINE_LEN - 2) < 0) {}
+  ssize_t num = read(0, in_buf, MAX_CMDLINE_LEN - 2);
+  if (num < 1) { _exit(1); }
+  in_buf[num] = '\0';
+  in_buf[num + 1] = '\0';
 
   while (*ptr && rc < MAX_CMDLINE_PAR) {
 
diff --git a/utils/libtokencap/README.md b/utils/libtokencap/README.md
index 50104291..8705452c 100644
--- a/utils/libtokencap/README.md
+++ b/utils/libtokencap/README.md
@@ -47,9 +47,11 @@ by AFL++ in that earlier run. This demonstrates the basic principle:
 
 ```
   export AFL_TOKEN_FILE=$PWD/temp_output.txt
+  timeout_sec="5"
 
   for i in <out_dir>/queue/id*; do
     LD_PRELOAD=/path/to/libtokencap.so \
+    timeout -s SIGKILL ${timeout_sec} \
       /path/to/target/program [...params, including $i...]
   done