Merge pull request #477 from AFLplusplus/dev

Push to stable

20 files changed, 1066 insertions, 147 deletions

diff --git a/examples/afl_frida/GNUmakefile b/examples/afl_frida/GNUmakefile
new file mode 100644
index 00000000..c154f3a4
--- /dev/null
+++ b/examples/afl_frida/GNUmakefile
@@ -0,0 +1,23 @@
+ifdef DEBUG
+  OPT=-O0 -D_DEBUG=\"1\"
+else
+  OPT=-O3 -funroll-loops
+endif
+
+all:	afl-frida libtestinstr.so
+
+libfrida-gum.a:
+	@echo Download and extract frida-gum-devkit-VERSION-PLATFORM.tar.xz for your platform from https://github.com/frida/frida/releases/latest
+	@exit 1
+	
+afl-frida:	afl-frida.c libfrida-gum.a
+	$(CC) -g $(OPT) -o afl-frida -Wno-format -Wno-pointer-sign -I. -fpermissive -fPIC afl-frida.c ../../afl-llvm-rt.o libfrida-gum.a -ldl -lresolv -pthread
+
+libtestinstr.so:        libtestinstr.c
+	$(CC) -g -O0 -fPIC -o libtestinstr.so -shared libtestinstr.c
+
+clean:
+	rm -f afl-frida *~ core *.o libtestinstr.so
+
+deepclean: clean
+	rm -f libfrida-gum.a frida-gum*
diff --git a/examples/afl_frida/Makefile b/examples/afl_frida/Makefile
new file mode 100644
index 00000000..0b306dde
--- /dev/null
+++ b/examples/afl_frida/Makefile
@@ -0,0 +1,2 @@
+all:
+	@echo please use GNU make, thanks!
diff --git a/examples/afl_frida/README.md b/examples/afl_frida/README.md
new file mode 100644
index 00000000..7743479b
--- /dev/null
+++ b/examples/afl_frida/README.md
@@ -0,0 +1,34 @@
+# afl-frida - faster fuzzing of binary-only libraries
+
+## Introduction
+
+afl-frida is an example skeleton file which can easily be used to fuzz
+a closed source library.
+
+It requires less memory and is x5-10 faster than qemu_mode but does not
+provide interesting features like compcov or cmplog.
+
+## How-to
+
+### Modify afl-frida.c
+
+Read and modify afl-frida.c then `make`.
+To adapt afl-frida.c to your needs, read the header of the file and then
+search and edit the `STEP 1`, `STEP 2` and `STEP 3` locations.
+
+### Fuzzing
+
+Example (after modifying afl-frida.c to your needs and compile it):
+```
+LD_LIBRARY_PATH=/path/to/the/target/library afl-fuzz -i in -o out -- ./afl-frida
+```
+(or even remote via afl-network-proxy).
+
+# Speed and stability
+
+The speed is very good, about x12 of fork() qemu_mode.
+However the stability is low. Reason is currently unknown.
+
+# Background
+
+This code is copied for a larger part from https://github.com/meme/hotwax
diff --git a/examples/afl_frida/afl-frida.c b/examples/afl_frida/afl-frida.c
new file mode 100644
index 00000000..2ad5a72a
--- /dev/null
+++ b/examples/afl_frida/afl-frida.c
@@ -0,0 +1,541 @@
+/*
+   american fuzzy lop++ - afl-frida skeleton example
+   -------------------------------------------------
+
+   Copyright 2020 AFLplusplus Project. All rights reserved.
+
+   Written mostly by meme -> https://github.com/meme/hotwax
+
+   Modificationy by Marc Heuse <mh@mh-sec.de>
+
+   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
+
+   HOW-TO
+   ======
+
+   You only need to change the following:
+
+   1. set the defines and function call parameters.
+   2. dl load the library you want to fuzz, lookup the functions you need
+      and setup the calls to these.
+   3. in the while loop you call the functions in the necessary order -
+      incl the cleanup. the cleanup is important!
+
+   Just look these steps up in the code, look for "// STEP x:"
+
+*/
+
+#include <stdio.h>
+#include <stdint.h>
+#include <unistd.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <sys/shm.h>
+#include <dlfcn.h>
+
+#ifndef __APPLE__
+  #include <sys/wait.h>
+  #include <sys/personality.h>
+#endif
+
+int debug = 0;
+
+// STEP 1:
+
+// The presets are for the example libtestinstr.so:
+
+/* What is the name of the library to fuzz */
+#define TARGET_LIBRARY "libtestinstr.so"
+
+/* What is the name of the function to fuzz */
+#define TARGET_FUNCTION "testinstr"
+
+/* here you need to specify the parameter for the target function */
+static void *(*o_function)(uint8_t *, int);
+
+// END STEP 1
+
+#include "frida-gum.h"
+
+G_BEGIN_DECLS
+
+#define GUM_TYPE_FAKE_EVENT_SINK (gum_fake_event_sink_get_type())
+G_DECLARE_FINAL_TYPE(GumFakeEventSink, gum_fake_event_sink, GUM,
+                     FAKE_EVENT_SINK, GObject)
+
+struct _GumFakeEventSink {
+
+  GObject      parent;
+  GumEventType mask;
+
+};
+
+GumEventSink *gum_fake_event_sink_new(void);
+void          gum_fake_event_sink_reset(GumFakeEventSink *self);
+
+G_END_DECLS
+
+static void         gum_fake_event_sink_iface_init(gpointer g_iface,
+                                                   gpointer iface_data);
+static void         gum_fake_event_sink_finalize(GObject *obj);
+static GumEventType gum_fake_event_sink_query_mask(GumEventSink *sink);
+static void gum_fake_event_sink_process(GumEventSink *sink, const GumEvent *ev);
+void instr_basic_block(GumStalkerIterator *iterator, GumStalkerOutput *output,
+                       gpointer user_data);
+void afl_setup(void);
+void afl_start_forkserver(void);
+int  __afl_persistent_loop(unsigned int max_cnt);
+
+static void gum_fake_event_sink_class_init(GumFakeEventSinkClass *klass) {
+
+  GObjectClass *object_class = G_OBJECT_CLASS(klass);
+  object_class->finalize = gum_fake_event_sink_finalize;
+
+}
+
+static void gum_fake_event_sink_iface_init(gpointer g_iface,
+                                           gpointer iface_data) {
+
+  GumEventSinkInterface *iface = (GumEventSinkInterface *)g_iface;
+  iface->query_mask = gum_fake_event_sink_query_mask;
+  iface->process = gum_fake_event_sink_process;
+
+}
+
+G_DEFINE_TYPE_EXTENDED(GumFakeEventSink, gum_fake_event_sink, G_TYPE_OBJECT, 0,
+                       G_IMPLEMENT_INTERFACE(GUM_TYPE_EVENT_SINK,
+                                             gum_fake_event_sink_iface_init))
+
+#include "../../config.h"
+
+// Shared memory fuzzing.
+int                   __afl_sharedmem_fuzzing = 1;
+extern unsigned int * __afl_fuzz_len;
+extern unsigned char *__afl_fuzz_ptr;
+
+// Notify AFL about persistent mode.
+static volatile char AFL_PERSISTENT[] = "##SIG_AFL_PERSISTENT##";
+int                  __afl_persistent_loop(unsigned int);
+
+// Notify AFL about deferred forkserver.
+static volatile char AFL_DEFER_FORKSVR[] = "##SIG_AFL_DEFER_FORKSRV##";
+void                 __afl_manual_init();
+
+// Because we do our own logging.
+extern uint8_t *        __afl_area_ptr;
+static __thread guint64 previous_pc;
+
+// Frida stuff below.
+typedef struct {
+
+  GumAddress base_address;
+  guint64    code_start, code_end;
+
+} range_t;
+
+inline static void afl_maybe_log(guint64 current_pc) {
+
+  // fprintf(stderr, "PC: %p ^ %p\n", current_pc, previous_pc);
+
+  current_pc = (current_pc >> 4) ^ (current_pc << 8);
+  current_pc &= MAP_SIZE - 1;
+
+  __afl_area_ptr[current_pc ^ previous_pc]++;
+  previous_pc = current_pc >> 1;
+
+}
+
+static void on_basic_block(GumCpuContext *context, gpointer user_data) {
+
+  afl_maybe_log((guint64)user_data);
+
+}
+
+void instr_basic_block(GumStalkerIterator *iterator, GumStalkerOutput *output,
+                       gpointer user_data) {
+
+  range_t *range = (range_t *)user_data;
+
+  const cs_insn *instr;
+  gboolean       begin = TRUE;
+  while (gum_stalker_iterator_next(iterator, &instr)) {
+
+    if (begin) {
+
+      if (instr->address >= range->code_start &&
+          instr->address <= range->code_end) {
+
+        gum_stalker_iterator_put_callout(iterator, on_basic_block,
+                                         (gpointer)instr->address, NULL);
+        begin = FALSE;
+
+      }
+
+    }
+
+    gum_stalker_iterator_keep(iterator);
+
+  }
+
+}
+
+static void gum_fake_event_sink_init(GumFakeEventSink *self) {
+
+}
+
+static void gum_fake_event_sink_finalize(GObject *obj) {
+
+  G_OBJECT_CLASS(gum_fake_event_sink_parent_class)->finalize(obj);
+
+}
+
+GumEventSink *gum_fake_event_sink_new(void) {
+
+  GumFakeEventSink *sink;
+  sink = (GumFakeEventSink *)g_object_new(GUM_TYPE_FAKE_EVENT_SINK, NULL);
+  return GUM_EVENT_SINK(sink);
+
+}
+
+void gum_fake_event_sink_reset(GumFakeEventSink *self) {
+
+}
+
+static GumEventType gum_fake_event_sink_query_mask(GumEventSink *sink) {
+
+  return 0;
+
+}
+
+typedef struct library_list {
+
+  uint8_t *name;
+  uint64_t addr_start, addr_end;
+
+} library_list_t;
+
+#define MAX_LIB_COUNT 256
+static library_list_t liblist[MAX_LIB_COUNT];
+static u32            liblist_cnt;
+
+void read_library_information() {
+
+#if defined(__linux__)
+  FILE *f;
+  u8    buf[1024], *b, *m, *e, *n;
+
+  if ((f = fopen("/proc/self/maps", "r")) == NULL) {
+
+    fprintf(stderr, "Error: cannot open /proc/self/maps\n");
+    exit(-1);
+
+  }
+
+  if (debug) fprintf(stderr, "Library list:\n");
+  while (fgets(buf, sizeof(buf), f)) {
+
+    if (strstr(buf, " r-x")) {
+
+      if (liblist_cnt >= MAX_LIB_COUNT) {
+
+        fprintf(
+            stderr,
+            "Warning: too many libraries to old, maximum count of %d reached\n",
+            liblist_cnt);
+        return;
+
+      }
+
+      b = buf;
+      m = index(buf, '-');
+      e = index(buf, ' ');
+      if ((n = rindex(buf, '/')) == NULL) n = rindex(buf, ' ');
+      if (n &&
+          ((*n >= '0' && *n <= '9') || *n == '[' || *n == '{' || *n == '('))
+        n = NULL;
+      else
+        n++;
+      if (b && m && e && n && *n) {
+
+        *m++ = 0;
+        *e = 0;
+        if (n[strlen(n) - 1] == '\n') n[strlen(n) - 1] = 0;
+
+        if (rindex(n, '/') != NULL) {
+
+          n = rindex(n, '/');
+          n++;
+
+        }
+
+        liblist[liblist_cnt].name = strdup(n);
+        liblist[liblist_cnt].addr_start = strtoull(b, NULL, 16);
+        liblist[liblist_cnt].addr_end = strtoull(m, NULL, 16);
+        if (debug)
+          fprintf(
+              stderr, "%s:%llx (%llx-%llx)\n", liblist[liblist_cnt].name,
+              liblist[liblist_cnt].addr_end - liblist[liblist_cnt].addr_start,
+              liblist[liblist_cnt].addr_start,
+              liblist[liblist_cnt].addr_end - 1);
+        liblist_cnt++;
+
+      }
+
+    }
+
+  }
+
+  if (debug) fprintf(stderr, "\n");
+
+#elif defined(__FreeBSD__)
+  int    mib[] = {CTL_KERN, KERN_PROC, KERN_PROC_VMMAP, getpid()};
+  char * buf, *start, *end;
+  size_t miblen = sizeof(mib) / sizeof(mib[0]);
+  size_t len;
+
+  if (debug) fprintf(stderr, "Library list:\n");
+  if (sysctl(mib, miblen, NULL, &len, NULL, 0) == -1) { return; }
+
+  len = len * 4 / 3;
+
+  buf = mmap(NULL, len, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANON, -1, 0);
+  if (buf == MAP_FAILED) { return; }
+  if (sysctl(mib, miblen, buf, &len, NULL, 0) == -1) {
+
+    munmap(buf, len);
+    return;
+
+  }
+
+  start = buf;
+  end = buf + len;
+
+  while (start < end) {
+
+    struct kinfo_vmentry *region = (struct kinfo_vmentry *)start;
+    size_t                size = region->kve_structsize;
+
+    if (size == 0) { break; }
+
+    if ((region->kve_protection & KVME_PROT_READ) &&
+        !(region->kve_protection & KVME_PROT_EXEC)) {
+
+      liblist[liblist_cnt].name =
+          region->kve_path[0] != '\0' ? strdup(region->kve_path) : 0;
+      liblist[liblist_cnt].addr_start = region->kve_start;
+      liblist[liblist_cnt].addr_end = region->kve_end;
+
+      if (debug) {
+
+        fprintf(stderr, "%s:%x (%lx-%lx)\n", liblist[liblist_cnt].name,
+                liblist[liblist_cnt].addr_end - liblist[liblist_cnt].addr_start,
+                liblist[liblist_cnt].addr_start,
+                liblist[liblist_cnt].addr_end - 1);
+
+      }
+
+      liblist_cnt++;
+
+    }
+
+    start += size;
+
+  }
+
+#endif
+
+}
+
+library_list_t *find_library(char *name) {
+
+  char *filename = rindex(name, '/');
+
+  if (filename)
+    filename++;
+  else
+    filename = name;
+
+#if defined(__linux__)
+  u32 i;
+  for (i = 0; i < liblist_cnt; i++)
+    if (strcmp(liblist[i].name, filename) == 0) return &liblist[i];
+#elif defined(__APPLE__) && defined(__LP64__)
+  kern_return_t         err;
+  static library_list_t lib;
+
+  // get the list of all loaded modules from dyld
+  // the task_info mach API will get the address of the dyld all_image_info
+  // struct for the given task from which we can get the names and load
+  // addresses of all modules
+  task_dyld_info_data_t  task_dyld_info;
+  mach_msg_type_number_t count = TASK_DYLD_INFO_COUNT;
+  err = task_info(mach_task_self(), TASK_DYLD_INFO,
+                  (task_info_t)&task_dyld_info, &count);
+
+  const struct dyld_all_image_infos *all_image_infos =
+      (const struct dyld_all_image_infos *)task_dyld_info.all_image_info_addr;
+  const struct dyld_image_info *image_infos = all_image_infos->infoArray;
+
+  for (size_t i = 0; i < all_image_infos->infoArrayCount; i++) {
+
+    const char *      image_name = image_infos[i].imageFilePath;
+    mach_vm_address_t image_load_address =
+        (mach_vm_address_t)image_infos[i].imageLoadAddress;
+    if (strstr(image_name, name)) {
+
+      lib.name = name;
+      lib.addr_start = (u64)image_load_address;
+      lib.addr_end = 0;
+      return &lib;
+
+    }
+
+  }
+
+#endif
+
+  return NULL;
+
+}
+
+static void gum_fake_event_sink_process(GumEventSink *  sink,
+                                        const GumEvent *ev) {
+
+}
+
+/* Because this CAN be called more than once, it will return the LAST range */
+static int enumerate_ranges(const GumRangeDetails *details,
+                            gpointer               user_data) {
+
+  GumMemoryRange *code_range = (GumMemoryRange *)user_data;
+  memcpy(code_range, details->range, sizeof(*code_range));
+  return 0;
+
+}
+
+int main() {
+
+#ifndef __APPLE__
+  (void)personality(ADDR_NO_RANDOMIZE);  // disable ASLR
+#endif
+
+  // STEP 2: load the library you want to fuzz and lookup the functions,
+  //         inclusive of the cleanup functions.
+  //         If there is just one function, then there is nothing to change
+  //         or add here.
+
+  void *dl = dlopen(TARGET_LIBRARY, RTLD_LAZY);
+  if (!dl) {
+
+    fprintf(stderr, "Could not load %s\n", TARGET_LIBRARY);
+    exit(-1);
+
+  }
+
+  if (!(o_function = dlsym(dl, TARGET_FUNCTION))) {
+
+    fprintf(stderr, "Could not find function %s\n", TARGET_FUNCTION);
+    exit(-1);
+
+  }
+
+  // END STEP 2
+
+  read_library_information();
+  library_list_t *lib = find_library(TARGET_LIBRARY);
+
+  if (lib == NULL) {
+
+    fprintf(stderr, "Could not find target library\n");
+    exit(-1);
+
+  }
+
+  gum_init_embedded();
+  if (!gum_stalker_is_supported()) {
+
+    gum_deinit_embedded();
+    return 1;
+
+  }
+
+  GumStalker *stalker = gum_stalker_new();
+
+  /*
+  This does not work here as we load a shared library. pretty sure this
+  would also be easily solvable with frida gum, but I already have all the
+  code I need from afl-untracer
+
+  GumAddress base_address = gum_module_find_base_address(TARGET_LIBRARY);
+  GumMemoryRange code_range;
+  gum_module_enumerate_ranges(TARGET_LIBRARY, GUM_PAGE_RX, enumerate_ranges,
+                              &code_range);
+  guint64 code_start = code_range.base_address - base_address;
+  guint64 code_end = (code_range.base_address + code_range.size) - base_address;
+  range_t instr_range = {base_address, code_start, code_end};
+  */
+  range_t instr_range = {0, lib->addr_start, lib->addr_end};
+
+  GumStalkerTransformer *transformer =
+      gum_stalker_transformer_make_from_callback(instr_basic_block,
+                                                 &instr_range, NULL);
+
+  GumEventSink *event_sink = gum_fake_event_sink_new();
+
+  // to ensure that the signatures are not optimized out
+  memcpy(__afl_area_ptr, (void *)AFL_PERSISTENT, sizeof(AFL_PERSISTENT) + 1);
+  memcpy(__afl_area_ptr + 32, (void *)AFL_DEFER_FORKSVR,
+         sizeof(AFL_DEFER_FORKSVR) + 1);
+  __afl_manual_init();
+
+  //
+  // any expensive target library initialization that has to be done just once
+  // - put that here
+  //
+
+  gum_stalker_follow_me(stalker, transformer, event_sink);
+
+  while (__afl_persistent_loop(UINT32_MAX) != 0) {
+
+    previous_pc = 0;  // Required!
+
+#ifdef _DEBUG
+    fprintf(stderr, "CLIENT crc: %016llx len: %u\n", hash64(__afl_fuzz_ptr, *__a
+    fprintf(stderr, "RECV:");
+    for (int i = 0; i < *__afl_fuzz_len; i++)
+      fprintf(stderr, "%02x", __afl_fuzz_ptr[i]);
+    fprintf(stderr,"\n");
+#endif
+
+    // STEP 3: ensure the minimum length is present and setup the target
+    //         function to fuzz.
+
+    if (*__afl_fuzz_len > 0) {
+
+      __afl_fuzz_ptr[*__afl_fuzz_len] = 0;  // if you need to null terminate
+      (*o_function)(__afl_fuzz_ptr, *__afl_fuzz_len);
+
+    }
+
+    // END STEP 3
+
+  }
+
+  gum_stalker_unfollow_me(stalker);
+
+  while (gum_stalker_garbage_collect(stalker))
+    g_usleep(10000);
+
+  g_object_unref(stalker);
+  g_object_unref(transformer);
+  g_object_unref(event_sink);
+  gum_deinit_embedded();
+
+  return 0;
+
+}
+
diff --git a/examples/afl_frida/afl-frida.h b/examples/afl_frida/afl-frida.h
new file mode 100644
index 00000000..efa3440f
--- /dev/null
+++ b/examples/afl_frida/afl-frida.h
@@ -0,0 +1,53 @@
+extern int is_persistent;
+
+G_BEGIN_DECLS
+
+#define GUM_TYPE_FAKE_EVENT_SINK (gum_fake_event_sink_get_type())
+
+G_DECLARE_FINAL_TYPE(GumFakeEventSink, gum_fake_event_sink, GUM,
+                     FAKE_EVENT_SINK, GObject)
+
+struct _GumFakeEventSink {
+
+  GObject      parent;
+  GumEventType mask;
+
+};
+
+GumEventSink *gum_fake_event_sink_new(void);
+void          gum_fake_event_sink_reset(GumFakeEventSink *self);
+
+G_END_DECLS
+
+typedef struct {
+
+  GumAddress base_address;
+  guint64    code_start, code_end;
+
+} range_t;
+
+void instr_basic_block(GumStalkerIterator *iterator, GumStalkerOutput *output,
+                       gpointer user_data);
+#pragma once
+
+void afl_setup(void);
+void afl_start_forkserver(void);
+int  __afl_persistent_loop(unsigned int max_cnt);
+
+inline static inline void afl_maybe_log(guint64 current_pc) {
+
+  extern unsigned int afl_instr_rms;
+  extern uint8_t *    afl_area_ptr;
+
+  static __thread guint64 previous_pc;
+
+  current_pc = (current_pc >> 4) ^ (current_pc << 8);
+  current_pc &= MAP_SIZE - 1;
+
+  if (current_pc >= afl_instr_rms) return;
+
+  afl_area_ptr[current_pc ^ previous_pc]++;
+  previous_pc = current_pc >> 1;
+
+}
+
diff --git a/examples/afl_frida/libtestinstr.c b/examples/afl_frida/libtestinstr.c
new file mode 100644
index 00000000..96b1cf21
--- /dev/null
+++ b/examples/afl_frida/libtestinstr.c
@@ -0,0 +1,35 @@
+/*
+   american fuzzy lop++ - a trivial program to test the build
+   --------------------------------------------------------
+   Originally written by Michal Zalewski
+   Copyright 2014 Google Inc. All rights reserved.
+   Copyright 2019-2020 AFLplusplus Project. 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
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+void testinstr(char *buf, int len) {
+
+  if (len < 1) return;
+  buf[len] = 0;
+
+  // we support three input cases
+  if (buf[0] == '0')
+    printf("Looks like a zero to me!\n");
+  else if (buf[0] == '1')
+    printf("Pretty sure that is a one!\n");
+  else
+    printf("Neither one or zero? How quaint!\n");
+
+}
+
diff --git a/examples/afl_network_proxy/afl-network-client.c b/examples/afl_network_proxy/afl-network-client.c
index 5af41055..a2451fdc 100644
--- a/examples/afl_network_proxy/afl-network-client.c
+++ b/examples/afl_network_proxy/afl-network-client.c
@@ -34,7 +34,9 @@
 #include <netinet/ip6.h>
 #include <arpa/inet.h>
 #include <sys/mman.h>
-#include <sys/shm.h>
+#ifndef USEMMAP
+  #include <sys/shm.h>
+#endif
 #include <sys/wait.h>
 #include <sys/types.h>
 #include <sys/socket.h>
diff --git a/examples/afl_untracer/README.md b/examples/afl_untracer/README.md
index e59792cb..ada0c916 100644
--- a/examples/afl_untracer/README.md
+++ b/examples/afl_untracer/README.md
@@ -32,13 +32,14 @@ To easily run the scripts without needing to run the GUI with Ghidra:
 /opt/ghidra/support/analyzeHeadless /tmp/ tmp$$ -import libtestinstr.so -postscript ./ghidra_get_patchpoints.java
 rm -rf /tmp/tmp$$
 ```
+The file is created at `~/Desktop/patches.txt`
 
 ### Fuzzing
 
 Example (after modifying afl-untracer.c to your needs, compiling and creating
 patches.txt):
 ```
-AFL_UNTRACER_FILE=./patches.txt afl-fuzz -i in -o out -- ./afl-untracer
+LD_LIBRARY_PATH=/path/to/target/library AFL_UNTRACER_FILE=./patches.txt afl-fuzz -i in -o out -- ./afl-untracer
 ```
 (or even remote via afl-network-proxy).
 
diff --git a/examples/afl_untracer/TODO b/examples/afl_untracer/TODO
new file mode 100644
index 00000000..fffffacf
--- /dev/null
+++ b/examples/afl_untracer/TODO
@@ -0,0 +1,2 @@
+ * add shmem fuzzing
+ * add snapshot feature?
diff --git a/examples/afl_untracer/afl-untracer.c b/examples/afl_untracer/afl-untracer.c
index 664e691c..77b15eb8 100644
--- a/examples/afl_untracer/afl-untracer.c
+++ b/examples/afl_untracer/afl-untracer.c
@@ -56,6 +56,7 @@
 #include <sys/shm.h>
 #include <sys/wait.h>
 #include <sys/types.h>
+#include <sys/personality.h>
 
 #if defined(__linux__)
   #include <sys/ucontext.h>
@@ -73,6 +74,9 @@
 
 // STEP 1:
 
+/* here you need to specify the parameter for the target function */
+static void *(*o_function)(u8 *buf, int len);
+
 /* use stdin (1) or a file on the commandline (0) */
 static u32 use_stdin = 1;
 
@@ -111,10 +115,10 @@ static library_list_t liblist[MAX_LIB_COUNT];
 static u32            liblist_cnt;
 
 static void sigtrap_handler(int signum, siginfo_t *si, void *context);
-static void fuzz();
+static void fuzz(void);
 
 /* read the library information */
-void read_library_information() {
+void read_library_information(void) {
 
 #if defined(__linux__)
   FILE *f;
@@ -280,7 +284,7 @@ library_list_t *find_library(char *name) {
 // this seems to work for clang too. nice :) requires gcc 4.4+
 #pragma GCC push_options
 #pragma GCC optimize("O0")
-void        breakpoint() {
+void        breakpoint(void) {
 
   if (debug) fprintf(stderr, "Breakpoint function \"breakpoint\" reached.\n");
 
@@ -395,7 +399,7 @@ static void __afl_map_shm(void) {
 }
 
 /* Fork server logic. */
-static void __afl_start_forkserver(void) {
+inline static void __afl_start_forkserver(void) {
 
   u8  tmp[4] = {0, 0, 0, 0};
   u32 status = 0;
@@ -411,7 +415,7 @@ static void __afl_start_forkserver(void) {
 
 }
 
-static u32 __afl_next_testcase(u8 *buf, u32 max_len) {
+inline static u32 __afl_next_testcase(u8 *buf, u32 max_len) {
 
   s32 status;
 
@@ -437,7 +441,7 @@ static u32 __afl_next_testcase(u8 *buf, u32 max_len) {
 
 }
 
-static void __afl_end_testcase(int status) {
+inline static void __afl_end_testcase(int status) {
 
   if (write(FORKSRV_FD + 1, &status, 4) != 4) do_exit = 1;
   // fprintf(stderr, "write2 %d\n", do_exit);
@@ -457,7 +461,7 @@ static void __afl_end_testcase(int status) {
                   ((uintptr_t)addr & 0x3) * 0x10000000000))
 #endif
 
-void setup_trap_instrumentation() {
+void setup_trap_instrumentation(void) {
 
   library_list_t *lib_base = NULL;
   size_t          lib_size = 0;
@@ -667,12 +671,11 @@ static void sigtrap_handler(int signum, siginfo_t *si, void *context) {
 
 }
 
-/* here you need to specify the parameter for the target function */
-static void *(*o_function)(u8 *buf, int len);
-
 /* the MAIN function */
 int main(int argc, char *argv[]) {
 
+  (void)personality(ADDR_NO_RANDOMIZE);  // disable ASLR
+
   pid = getpid();
   if (getenv("AFL_DEBUG")) debug = 1;
 
@@ -706,6 +709,9 @@ int main(int argc, char *argv[]) {
 
   while (1) {
 
+    // instead of fork() we could also use the snapshot lkm or do our own mini
+    // snapshot feature like in https://github.com/marcinguy/fuzzer
+    // -> snapshot.c
     if ((pid = fork()) == -1) PFATAL("fork failed");
 
     if (pid) {
@@ -738,7 +744,11 @@ int main(int argc, char *argv[]) {
 
 }
 
-static void fuzz() {
+#ifndef _DEBUG
+inline
+#endif
+    static void
+    fuzz(void) {
 
   // STEP 3: call the function to fuzz, also the functions you might
   //         need to call to prepare the function and - important! -
diff --git a/examples/aflpp_driver/GNUmakefile b/examples/aflpp_driver/GNUmakefile
index a993c8a9..b118a8b5 100644
--- a/examples/aflpp_driver/GNUmakefile
+++ b/examples/aflpp_driver/GNUmakefile
@@ -7,25 +7,25 @@ ifneq "" "$(LLVM_BINDIR)"
   LLVM_BINDIR := $(LLVM_BINDIR)/
 endif
 
-FLAGS=-O3 -funroll-loops -g
+CFLAGS := -O3 -funroll-loops -g
 
 all:	libAFLDriver.a libAFLQemuDriver.a aflpp_qemu_driver_hook.so
 
-aflpp_driver.o:	aflpp_driver.cpp
-	$(LLVM_BINDIR)clang++ $(FLAGS) -stdlib=libc++ -std=c++11 -c aflpp_driver.cpp
+aflpp_driver.o:	aflpp_driver.c
+	$(LLVM_BINDIR)clang -I. -I../../include $(CFLAGS) -c aflpp_driver.c
 
 libAFLDriver.a:	aflpp_driver.o
 	ar ru libAFLDriver.a aflpp_driver.o
 
 debug:
-	$(LLVM_BINDIR)clang++ -Wno-deprecated -I../../include $(FLAGS) -D_DEBUG=\"1\" -c -o afl-performance.o ../../src/afl-performance.c
-	$(LLVM_BINDIR)clang++ -I../../include -D_DEBUG=\"1\" -g -stdlib=libc++ -funroll-loops -std=c++11 -c aflpp_driver.cpp
-	#$(LLVM_BINDIR)clang++ -S -emit-llvm -Wno-deprecated -I../../include $(FLAGS) -D_DEBUG=\"1\" -c -o afl-performance.ll ../../src/afl-performance.c
-	#$(LLVM_BINDIR)clang++ -S -emit-llvm -I../../include -D_DEBUG=\"1\" -g -stdlib=libc++ -funroll-loops -std=c++11 -c aflpp_driver.cpp
+	$(LLVM_BINDIR)clang -Wno-deprecated -I../../include $(CFLAGS) -D_DEBUG=\"1\" -c -o afl-performance.o ../../src/afl-performance.c
+	$(LLVM_BINDIR)clang -I../../include -D_DEBUG=\"1\" -g -funroll-loops -c aflpp_driver.c
+	#$(LLVM_BINDIR)clang -S -emit-llvm -Wno-deprecated -I../../include $(CFLAGS) -D_DEBUG=\"1\" -c -o afl-performance.ll ../../src/afl-performance.c
+	#$(LLVM_BINDIR)clang -S -emit-llvm -I../../include -D_DEBUG=\"1\" -g -funroll-loops -c aflpp_driver.c
 	ar ru libAFLDriver.a afl-performance.o aflpp_driver.o
 
 aflpp_qemu_driver.o:	aflpp_qemu_driver.c
-	$(LLVM_BINDIR)clang $(FLAGS) -O0 -funroll-loops -c aflpp_qemu_driver.c
+	$(LLVM_BINDIR)clang $(CFLAGS) -O0 -funroll-loops -c aflpp_qemu_driver.c
 
 libAFLQemuDriver.a:	aflpp_qemu_driver.o
 	ar ru libAFLQemuDriver.a aflpp_qemu_driver.o
@@ -34,11 +34,11 @@ aflpp_qemu_driver_hook.so:	aflpp_qemu_driver_hook.o
 	$(LLVM_BINDIR)clang -shared aflpp_qemu_driver_hook.o -o aflpp_qemu_driver_hook.so
 
 aflpp_qemu_driver_hook.o:	aflpp_qemu_driver_hook.c
-	$(LLVM_BINDIR)clang -fPIC $(FLAGS) -funroll-loops -c aflpp_qemu_driver_hook.c
+	$(LLVM_BINDIR)clang -fPIC $(CFLAGS) -funroll-loops -c aflpp_qemu_driver_hook.c
 
 test:	debug
-	#clang++ -S -emit-llvm -D_DEBUG=\"1\" -I../../include -Wl,--allow-multiple-definition -stdlib=libc++ -funroll-loops -std=c++11 -o aflpp_driver_test.ll aflpp_driver_test.cpp
-	afl-clang-fast++ -D_DEBUG=\"1\" -I../../include -Wl,--allow-multiple-definition -stdlib=libc++ -funroll-loops -std=c++11 -o aflpp_driver_test aflpp_driver_test.cpp libAFLDriver.a
+	#clang -S -emit-llvm -D_DEBUG=\"1\" -I../../include -Wl,--allow-multiple-definition -funroll-loops -o aflpp_driver_test.ll aflpp_driver_test.c
+	afl-clang-fast -D_DEBUG=\"1\" -I../../include -Wl,--allow-multiple-definition -funroll-loops -o aflpp_driver_test aflpp_driver_test.c libAFLDriver.a afl-performance.o
 
 clean:
 	rm -f *.o libAFLDriver*.a libAFLQemuDriver.a aflpp_qemu_driver_hook.so *~ core aflpp_driver_test
diff --git a/examples/aflpp_driver/aflpp_driver.cpp b/examples/aflpp_driver/aflpp_driver.c
index d6163bdf..86c7a69f 100644
--- a/examples/aflpp_driver/aflpp_driver.cpp
+++ b/examples/aflpp_driver/aflpp_driver.c
@@ -14,12 +14,15 @@ cat << EOF > test_fuzzer.cc
 #include <stddef.h>
 #include <stdint.h>
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
+
   if (size > 0 && data[0] == 'H')
     if (size > 1 && data[1] == 'I')
        if (size > 2 && data[2] == '!')
        __builtin_trap();
   return 0;
+
 }
+
 EOF
 # Build your target with -fsanitize-coverage=trace-pc-guard using fresh clang.
 clang -g -fsanitize-coverage=trace-pc-guard test_fuzzer.cc -c
@@ -49,188 +52,195 @@ If 1, close stdout at startup. If 2 close stderr; if 3 close both.
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
+#include <limits.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
 
-#include <fstream>
-#include <iostream>
-#include <vector>
+#include "config.h"
 
 #ifdef _DEBUG
-#include "hash.h"
+  #include "hash.h"
 #endif
 
 // Platform detection. Copied from FuzzerInternal.h
 #ifdef __linux__
-#define LIBFUZZER_LINUX 1
-#define LIBFUZZER_APPLE 0
-#define LIBFUZZER_NETBSD 0
-#define LIBFUZZER_FREEBSD 0
-#define LIBFUZZER_OPENBSD 0
+  #define LIBFUZZER_LINUX 1
+  #define LIBFUZZER_APPLE 0
+  #define LIBFUZZER_NETBSD 0
+  #define LIBFUZZER_FREEBSD 0
+  #define LIBFUZZER_OPENBSD 0
 #elif __APPLE__
-#define LIBFUZZER_LINUX 0
-#define LIBFUZZER_APPLE 1
-#define LIBFUZZER_NETBSD 0
-#define LIBFUZZER_FREEBSD 0
-#define LIBFUZZER_OPENBSD 0
+  #define LIBFUZZER_LINUX 0
+  #define LIBFUZZER_APPLE 1
+  #define LIBFUZZER_NETBSD 0
+  #define LIBFUZZER_FREEBSD 0
+  #define LIBFUZZER_OPENBSD 0
 #elif __NetBSD__
-#define LIBFUZZER_LINUX 0
-#define LIBFUZZER_APPLE 0
-#define LIBFUZZER_NETBSD 1
-#define LIBFUZZER_FREEBSD 0
-#define LIBFUZZER_OPENBSD 0
+  #define LIBFUZZER_LINUX 0
+  #define LIBFUZZER_APPLE 0
+  #define LIBFUZZER_NETBSD 1
+  #define LIBFUZZER_FREEBSD 0
+  #define LIBFUZZER_OPENBSD 0
 #elif __FreeBSD__
-#define LIBFUZZER_LINUX 0
-#define LIBFUZZER_APPLE 0
-#define LIBFUZZER_NETBSD 0
-#define LIBFUZZER_FREEBSD 1
-#define LIBFUZZER_OPENBSD 0
+  #define LIBFUZZER_LINUX 0
+  #define LIBFUZZER_APPLE 0
+  #define LIBFUZZER_NETBSD 0
+  #define LIBFUZZER_FREEBSD 1
+  #define LIBFUZZER_OPENBSD 0
 #elif __OpenBSD__
-#define LIBFUZZER_LINUX 0
-#define LIBFUZZER_APPLE 0
-#define LIBFUZZER_NETBSD 0
-#define LIBFUZZER_FREEBSD 0
-#define LIBFUZZER_OPENBSD 1
+  #define LIBFUZZER_LINUX 0
+  #define LIBFUZZER_APPLE 0
+  #define LIBFUZZER_NETBSD 0
+  #define LIBFUZZER_FREEBSD 0
+  #define LIBFUZZER_OPENBSD 1
 #else
-#error "Support for your platform has not been implemented"
+  #error "Support for your platform has not been implemented"
 #endif
 
-int __afl_sharedmem_fuzzing = 1;
-extern unsigned int *__afl_fuzz_len;
+int                   __afl_sharedmem_fuzzing = 1;
+extern unsigned int * __afl_fuzz_len;
 extern unsigned char *__afl_fuzz_ptr;
 
 // libFuzzer interface is thin, so we don't include any libFuzzer headers.
-extern "C" {
 int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size);
 __attribute__((weak)) int LLVMFuzzerInitialize(int *argc, char ***argv);
-}
 
 // Notify AFL about persistent mode.
 static volatile char AFL_PERSISTENT[] = "##SIG_AFL_PERSISTENT##";
-extern "C" int __afl_persistent_loop(unsigned int);
-static volatile char suppress_warning2 = AFL_PERSISTENT[0];
+int                  __afl_persistent_loop(unsigned int);
 
 // Notify AFL about deferred forkserver.
 static volatile char AFL_DEFER_FORKSVR[] = "##SIG_AFL_DEFER_FORKSRV##";
-extern "C" void __afl_manual_init();
-static volatile char suppress_warning1 = AFL_DEFER_FORKSVR[0];
-
-// Input buffer.
-static const size_t kMaxAflInputSize = 1 << 20;
-static uint8_t AflInputBuf[kMaxAflInputSize];
+void                 __afl_manual_init();
 
 // Use this optionally defined function to output sanitizer messages even if
 // user asks to close stderr.
-__attribute__((weak)) extern "C" void __sanitizer_set_report_fd(void *);
+__attribute__((weak)) void __sanitizer_set_report_fd(void *);
 
 // Keep track of where stderr content is being written to, so that
 // dup_and_close_stderr can use the correct one.
-static FILE *output_file = stderr;
+static FILE *output_file;
 
 // Experimental feature to use afl_driver without AFL's deferred mode.
 // Needs to run before __afl_auto_init.
 __attribute__((constructor(0))) static void __decide_deferred_forkserver(void) {
+
   if (getenv("AFL_DRIVER_DONT_DEFER")) {
+
     if (unsetenv("__AFL_DEFER_FORKSRV")) {
+
       perror("Failed to unset __AFL_DEFER_FORKSRV");
       abort();
+
     }
+
   }
+
 }
 
 // If the user asks us to duplicate stderr, then do it.
 static void maybe_duplicate_stderr() {
+
   char *stderr_duplicate_filename =
       getenv("AFL_DRIVER_STDERR_DUPLICATE_FILENAME");
 
-  if (!stderr_duplicate_filename)
-    return;
+  if (!stderr_duplicate_filename) return;
 
   FILE *stderr_duplicate_stream =
       freopen(stderr_duplicate_filename, "a+", stderr);
 
   if (!stderr_duplicate_stream) {
+
     fprintf(
         stderr,
         "Failed to duplicate stderr to AFL_DRIVER_STDERR_DUPLICATE_FILENAME");
     abort();
+
   }
+
   output_file = stderr_duplicate_stream;
+
 }
 
 // Most of these I/O functions were inspired by/copied from libFuzzer's code.
 static void discard_output(int fd) {
+
   FILE *temp = fopen("/dev/null", "w");
-  if (!temp)
-    abort();
+  if (!temp) abort();
   dup2(fileno(temp), fd);
   fclose(temp);
+
 }
 
-static void close_stdout() { discard_output(STDOUT_FILENO); }
+static void close_stdout() {
+
+  discard_output(STDOUT_FILENO);
+
+}
 
 // Prevent the targeted code from writing to "stderr" but allow sanitizers and
 // this driver to do so.
 static void dup_and_close_stderr() {
+
   int output_fileno = fileno(output_file);
   int output_fd = dup(output_fileno);
-  if (output_fd <= 0)
-    abort();
+  if (output_fd <= 0) abort();
   FILE *new_output_file = fdopen(output_fd, "w");
-  if (!new_output_file)
-    abort();
-  if (!__sanitizer_set_report_fd)
-    return;
-  __sanitizer_set_report_fd(reinterpret_cast<void *>(output_fd));
+  if (!new_output_file) abort();
+  if (!__sanitizer_set_report_fd) return;
+  __sanitizer_set_report_fd((void *)output_fd);
   discard_output(output_fileno);
-}
 
-static void Printf(const char *Fmt, ...) {
-  va_list ap;
-  va_start(ap, Fmt);
-  vfprintf(output_file, Fmt, ap);
-  va_end(ap);
-  fflush(output_file);
 }
 
 // Close stdout and/or stderr if user asks for it.
 static void maybe_close_fd_mask() {
+
   char *fd_mask_str = getenv("AFL_DRIVER_CLOSE_FD_MASK");
-  if (!fd_mask_str)
-    return;
+  if (!fd_mask_str) return;
   int fd_mask = atoi(fd_mask_str);
-  if (fd_mask & 2)
-    dup_and_close_stderr();
-  if (fd_mask & 1)
-    close_stdout();
+  if (fd_mask & 2) dup_and_close_stderr();
+  if (fd_mask & 1) close_stdout();
+
 }
 
 // Define LLVMFuzzerMutate to avoid link failures for targets that use it
 // with libFuzzer's LLVMFuzzerCustomMutator.
-extern "C" size_t LLVMFuzzerMutate(uint8_t *Data, size_t Size, size_t MaxSize) {
-  assert(false && "LLVMFuzzerMutate should not be called from afl_driver");
+size_t LLVMFuzzerMutate(uint8_t *Data, size_t Size, size_t MaxSize) {
+
+  // assert(false && "LLVMFuzzerMutate should not be called from afl_driver");
   return 0;
+
 }
 
 // Execute any files provided as parameters.
 static int ExecuteFilesOnyByOne(int argc, char **argv) {
+
+  unsigned char *buf = malloc(MAX_FILE);
   for (int i = 1; i < argc; i++) {
-    std::ifstream in(argv[i], std::ios::binary);
-    in.seekg(0, in.end);
-    size_t length = in.tellg();
-    in.seekg (0, in.beg);
-    std::cout << "Reading " << length << " bytes from " << argv[i] << std::endl;
-    // Allocate exactly length bytes so that we reliably catch buffer overflows.
-    std::vector<char> bytes(length);
-    in.read(bytes.data(), bytes.size());
-    assert(in);
-    LLVMFuzzerTestOneInput(reinterpret_cast<const uint8_t *>(bytes.data()),
-                           bytes.size());
-    std::cout << "Execution successful" << std::endl;
+
+    int fd = open(argv[i], O_RDONLY);
+    if (fd == -1) continue;
+    ssize_t length = read(fd, buf, MAX_FILE);
+    if (length > 0) {
+
+      printf("Reading %zu bytes from %s\n", length, argv[i]);
+      LLVMFuzzerTestOneInput(buf, length);
+      printf("Execution successful.\n");
+
+    }
+
   }
+
+  free(buf);
   return 0;
+
 }
 
 int main(int argc, char **argv) {
-  Printf(
+
+  printf(
       "======================= INFO =========================\n"
       "This binary is built for AFL-fuzz.\n"
       "To run the target function on individual input(s) execute this:\n"
@@ -242,32 +252,39 @@ int main(int argc, char **argv) {
       "afl-fuzz will run N iterations before "
       "re-spawning the process (default: 1000)\n"
       "======================================================\n",
-          argv[0], argv[0], argv[0]);
+      argv[0], argv[0], argv[0]);
 
+  output_file = stderr;
   maybe_duplicate_stderr();
   maybe_close_fd_mask();
-  if (LLVMFuzzerInitialize)
-    LLVMFuzzerInitialize(&argc, &argv);
+  if (LLVMFuzzerInitialize) LLVMFuzzerInitialize(&argc, &argv);
+
   // Do any other expensive one-time initialization here.
 
-  uint8_t dummy_input[1] = {0};
-  int N = 100000;
+  uint8_t dummy_input[64] = {0};
+  memcpy(dummy_input, (void *)AFL_PERSISTENT, sizeof(AFL_PERSISTENT));
+  memcpy(dummy_input + 32, (void *)AFL_DEFER_FORKSVR,
+         sizeof(AFL_DEFER_FORKSVR));
+  int N = INT_MAX;
   if (argc == 2 && argv[1][0] == '-')
-      N = atoi(argv[1] + 1);
-  else if(argc == 2 && (N = atoi(argv[1])) > 0)
-      Printf("WARNING: using the deprecated call style `%s %d`\n", argv[0], N);
+    N = atoi(argv[1] + 1);
+  else if (argc == 2 && (N = atoi(argv[1])) > 0)
+    printf("WARNING: using the deprecated call style `%s %d`\n", argv[0], N);
   else if (argc > 1) {
-//    if (!getenv("AFL_DRIVER_DONT_DEFER")) {
-      __afl_sharedmem_fuzzing = 0;
-      __afl_manual_init();
-//    }
+
+    //    if (!getenv("AFL_DRIVER_DONT_DEFER")) {
+
+    __afl_sharedmem_fuzzing = 0;
+    __afl_manual_init();
+    //    }
     return ExecuteFilesOnyByOne(argc, argv);
     exit(0);
+
   }
 
   assert(N > 0);
 
-//  if (!getenv("AFL_DRIVER_DONT_DEFER"))
+  //  if (!getenv("AFL_DRIVER_DONT_DEFER"))
   __afl_manual_init();
 
   // Call LLVMFuzzerTestOneInput here so that coverage caused by initialization
@@ -276,17 +293,26 @@ int main(int argc, char **argv) {
 
   int num_runs = 0;
   while (__afl_persistent_loop(N)) {
+
 #ifdef _DEBUG
-    fprintf(stderr, "CLIENT crc: %016llx len: %u\n", hash64(__afl_fuzz_ptr, *__afl_fuzz_len, 0xa5b35705), *__afl_fuzz_len);
+    fprintf(stderr, "CLIENT crc: %016llx len: %u\n",
+            hash64(__afl_fuzz_ptr, *__afl_fuzz_len, 0xa5b35705),
+            *__afl_fuzz_len);
     fprintf(stderr, "RECV:");
     for (int i = 0; i < *__afl_fuzz_len; i++)
       fprintf(stderr, "%02x", __afl_fuzz_ptr[i]);
-    fprintf(stderr,"\n");
+    fprintf(stderr, "\n");
 #endif
     if (*__afl_fuzz_len) {
+
       num_runs++;
       LLVMFuzzerTestOneInput(__afl_fuzz_ptr, *__afl_fuzz_len);
+
     }
+
   }
-  Printf("%s: successfully executed %d input(s)\n", argv[0], num_runs);
+
+  printf("%s: successfully executed %d input(s)\n", argv[0], num_runs);
+
 }
+
diff --git a/examples/aflpp_driver/aflpp_driver_test.c b/examples/aflpp_driver/aflpp_driver_test.c
new file mode 100644
index 00000000..e4567bbf
--- /dev/null
+++ b/examples/aflpp_driver/aflpp_driver_test.c
@@ -0,0 +1,25 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+
+#include "hash.h"
+
+int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {
+
+  fprintf(stderr, "FUNC crc: %016llx len: %lu\n",
+          hash64((u8 *)Data, (unsigned int)Size,
+                 (unsigned long long int)0xa5b35705),
+          Size);
+
+  if (Size < 5) return 0;
+
+  if (Data[0] == 'F')
+    if (Data[1] == 'A')
+      if (Data[2] == '$')
+        if (Data[3] == '$')
+          if (Data[4] == '$') abort();
+
+  return 0;
+
+}
+
diff --git a/examples/aflpp_driver/aflpp_driver_test.cpp b/examples/aflpp_driver/aflpp_driver_test.cpp
deleted file mode 100644
index 13dc09b9..00000000
--- a/examples/aflpp_driver/aflpp_driver_test.cpp
+++ /dev/null
@@ -1,22 +0,0 @@
-#include <stdio.h>
-#include <stdlib.h>
-#include <stdint.h>
-#include "hash.h"
-
-extern "C" int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {
-
-  fprintf(stderr, "FUNC crc: %016llx len: %lu\n", hash64((u8*)Data, (unsigned int) Size, (unsigned long long int) 0xa5b35705), Size);
-  
-  if (Size < 5)
-    return 0;
-
-  if (Data[0] == 'F')
-    if (Data[1] == 'A')
-      if (Data[2] == '$')
-        if (Data[3] == '$')
-          if (Data[4] == '$')
-            abort();
-          
-  return 0;
-
-}
diff --git a/examples/custom_mutators/post_library_gif.so.c b/examples/custom_mutators/post_library_gif.so.c
index 9b76ead5..2d72400c 100644
--- a/examples/custom_mutators/post_library_gif.so.c
+++ b/examples/custom_mutators/post_library_gif.so.c
@@ -83,7 +83,7 @@ typedef struct post_state {
 
 } post_state_t;
 
-void *afl afl_custom_init(void *afl) {
+void *afl_custom_init(void *afl) {
 
   post_state_t *state = malloc(sizeof(post_state_t));
   if (!state) {
diff --git a/examples/defork/Makefile b/examples/defork/Makefile
new file mode 100644
index 00000000..e8240dba
--- /dev/null
+++ b/examples/defork/Makefile
@@ -0,0 +1,64 @@
+#
+# american fuzzy lop++ - defork
+# ----------------------------------
+#
+# 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
+#
+
+.PHONY: all install clean
+
+PREFIX     ?= /usr/local
+BIN_PATH    = $(PREFIX)/bin
+HELPER_PATH = $(PREFIX)/lib/afl
+
+CFLAGS = -fPIC -Wall -Wextra
+LDFLAGS = -shared
+
+UNAME_SAYS_LINUX=$(shell uname | grep -E '^Linux|^GNU' >/dev/null; echo $$?)
+UNAME_SAYS_LINUX:sh=uname | grep -E '^Linux|^GNU' >/dev/null; echo $$?
+
+_LDFLAGS_ADD=$(UNAME_SAYS_LINUX:1=)
+LDFLAGS_ADD=$(_LDFLAGS_ADD:0=-ldl)
+LDFLAGS  += $(LDFLAGS_ADD)
+
+# on gcc for arm there is no -m32, but -mbe32
+M32FLAG = -m32
+M64FLAG = -m64
+
+CC_IS_GCC=$(shell $(CC) --version 2>/dev/null | grep -q gcc; echo $$?)
+CC_IS_GCC:sh=$(CC) --version 2>/dev/null | grep -q gcc; echo $$?
+CC_IS_ARMCOMPILER=$(shell $(CC) -v 2>&1 >/dev/null | grep -q arm; echo $$?)
+CC_IS_ARMCOMPILER:sh=$(CC) -v 2>&1 >/dev/null | grep -q arm; echo $$?
+
+_M32FLAG=$(CC_IS_GCC)$(CC_IS_ARMCOMPILER)
+__M32FLAG=$(_M32FLAG:00=-mbe32)
+___M32FLAG=$(__M32FLAG:$(CC_IS_GCC)$(CC_IS_ARMCOMPILER)=-m32)
+M32FLAG=$(___M32FLAG)
+#ifeq "$(findstring clang, $(shell $(CC) --version 2>/dev/null))" ""
+# ifneq (,$(findstring arm, "$(shell $(CC) -v 2>&1 >/dev/null)"))
+#  M32FLAG = -mbe32
+# endif
+#endif
+
+all: defork32.so defork64.so
+
+defork32.so: defork.c
+	-@$(CC) $(M32FLAG) $(CFLAGS) $^ $(LDFLAGS) -o $@ 2>/dev/null || echo "defork32 build failure (that's fine)"
+
+defork64.so: defork.c
+	-@$(CC) $(M64FLAG) $(CFLAGS) $^ $(LDFLAGS) -o $@ 2>/dev/null || echo "defork64 build failure (that's fine)"
+
+install: defork32.so defork64.so
+	install -d -m 755 $(DESTDIR)$(HELPER_PATH)/
+	if [ -f defork32.so ]; then set -e; install -m 755 defork32.so $(DESTDIR)$(HELPER_PATH)/; fi
+	if [ -f defork64.so ]; then set -e; install -m 755 defork64.so $(DESTDIR)$(HELPER_PATH)/; fi
+
+target:
+	../../afl-clang forking_target.c -o forking_target -Wall -Wextra -Werror
+
+clean:
+	rm -f defork32.so defork64.so forking_target
diff --git a/examples/defork/README.md b/examples/defork/README.md
new file mode 100644
index 00000000..7e950323
--- /dev/null
+++ b/examples/defork/README.md
@@ -0,0 +1,11 @@
+# defork
+
+when the target forks, this breaks all normal fuzzing runs.
+Sometimes, though, it is enough to just run the child process.
+If this is the case, then this LD_PRELOAD library will always return 0 on fork,
+the target will belive it is running as the child, post-fork.
+
+This is defork.c from the amazing preeny project
+https://github.com/zardus/preeny
+
+It is altered for afl++ to work with its fork-server: the initial fork will go through, the second fork will be blocked.
diff --git a/examples/defork/defork.c b/examples/defork/defork.c
new file mode 100644
index 00000000..f71d1124
--- /dev/null
+++ b/examples/defork/defork.c
@@ -0,0 +1,50 @@
+#define __GNU_SOURCE
+#include <dlfcn.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <stdbool.h>
+
+#include "../../include/config.h"
+
+/* we want to fork once (for the afl++ forkserver),
+   then immediately return as child on subsequent forks. */
+static bool forked = 0;
+
+pid_t (*original_fork)(void);
+
+/* In case we are not running in afl, we use a dummy original_fork */
+static pid_t nop(void) {
+
+  return 0;
+
+}
+
+__attribute__((constructor)) void preeny_fork_orig() {
+
+  if (getenv(SHM_ENV_VAR)) {
+
+    printf("defork: running in AFL++. Allowing forkserver.\n");
+    original_fork = dlsym(RTLD_NEXT, "socket");
+
+  } else {
+
+    printf("defork: no AFL++ detected. Disabling fork from the start.\n");
+    original_fork = &nop;
+
+  }
+
+}
+
+pid_t fork(void) {
+
+  /* If we forked before, or if we're in the child (pid==0),
+    we don't want to fork anymore, else, we are still in the forkserver.
+    The forkserver parent needs to fork infinite times, each child should never
+    fork again. This can be written without branches and I hate myself for it.
+  */
+  pid_t ret = !forked && original_fork();
+  forked = !ret;
+  return ret;
+
+}
+
diff --git a/examples/defork/forking_target.c b/examples/defork/forking_target.c
new file mode 100644
index 00000000..98f6365a
--- /dev/null
+++ b/examples/defork/forking_target.c
@@ -0,0 +1,48 @@
+#include <stdio.h>
+#include <unistd.h>
+#include <stdint.h>
+#include <sys/types.h>
+
+/* This is an example target for defork.c - fuzz using
+```
+mkdir in; echo a > ./in/a
+AFL_PRELOAD=./defork64.so ../../afl-fuzz -i in -o out -- ./forking_target @@
+```
+*/
+
+int main(int argc, char **argv) {
+
+  if (argc < 2) {
+
+    printf("Example tool to test defork.\nUsage ./forking_target <input>\n");
+    return -1;
+
+  }
+
+  pid_t pid = fork();
+  if (pid == 0) {
+
+    printf("We're in the child.\n");
+    FILE *f = fopen(argv[1], "r");
+    char  buf[4096];
+    fread(buf, 1, 4096, f);
+    uint32_t offset = buf[100] + (buf[101] << 8);
+    char     test_val = buf[offset];
+    return test_val < 100;
+
+  } else if (pid < 0) {
+
+    perror("fork");
+    return -1;
+
+  } else {
+
+    printf("We are in the parent - defork didn't work! :( (pid=%d)\n",
+           (int)pid);
+
+  }
+
+  return 0;
+
+}
+
diff --git a/examples/persistent_demo/persistent_demo_new.c b/examples/persistent_demo/persistent_demo_new.c
index e4e328b0..7f878c0c 100644
--- a/examples/persistent_demo/persistent_demo_new.c
+++ b/examples/persistent_demo/persistent_demo_new.c
@@ -28,6 +28,20 @@
 #include <signal.h>
 #include <string.h>
 
+/* this lets the source compile without afl-clang-fast/lto */
+#ifndef __AFL_FUZZ_TESTCASE_LEN
+
+ssize_t       fuzz_len;
+unsigned char fuzz_buf[1024000];
+
+  #define __AFL_FUZZ_TESTCASE_LEN fuzz_len
+  #define __AFL_FUZZ_TESTCASE_BUF fuzz_buf
+  #define __AFL_FUZZ_INIT() void sync(void);
+  #define __AFL_LOOP(x) ((fuzz_len = read(0, fuzz_buf, sizeof(fuzz_buf))) > 0 ?
+  #define __AFL_INIT() sync()
+
+#endif
+
 __AFL_FUZZ_INIT();
 
 /* Main entry point. */