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-rw-r--r--src/README.md24
-rw-r--r--src/README.src22
-rw-r--r--src/afl-analyze.c27
-rw-r--r--src/afl-common.c435
-rw-r--r--src/afl-forkserver.c292
-rw-r--r--src/afl-fuzz-bitmap.c169
-rw-r--r--src/afl-fuzz-cmplog.c597
-rw-r--r--src/afl-fuzz-extras.c35
-rw-r--r--src/afl-fuzz-init.c88
-rw-r--r--src/afl-fuzz-misc.c186
-rw-r--r--src/afl-fuzz-mutators.c147
-rw-r--r--src/afl-fuzz-one.c490
-rw-r--r--src/afl-fuzz-python.c318
-rw-r--r--src/afl-fuzz-queue.c119
-rw-r--r--src/afl-fuzz-redqueen.c21
-rw-r--r--src/afl-fuzz-run.c202
-rw-r--r--src/afl-fuzz-state.c (renamed from src/afl-fuzz-globals.c)54
-rw-r--r--src/afl-fuzz-stats.c368
-rw-r--r--src/afl-fuzz.c153
-rw-r--r--src/afl-gcc.c10
-rw-r--r--src/afl-gotcpu.c2
-rw-r--r--src/afl-sharedmem.c2
-rw-r--r--src/afl-showmap.c59
-rw-r--r--src/afl-tmin.c197
-rw-r--r--src/third_party/libradamsa/GNUmakefile (renamed from src/third_party/libradamsa/Makefile)0
-rw-r--r--src/third_party/libradamsa/libradamsa.c8
-rw-r--r--src/third_party/libradamsa/radamsa.h14
27 files changed, 1918 insertions, 2121 deletions
diff --git a/src/README.md b/src/README.md
new file mode 100644
index 00000000..6da534c3
--- /dev/null
+++ b/src/README.md
@@ -0,0 +1,24 @@
+# Source Folder
+
+Quick explanation about the files here:
+
+- `afl-analyze.c`		- afl-analyze binary tool
+- `afl-as.c`		- afl-as binary tool
+- `afl-gotcpu.c`		- afl-gotcpu binary tool
+- `afl-showmap.c`		- afl-showmap binary tool
+- `afl-tmin.c`		- afl-tmin binary tool
+- `afl-fuzz.c`		- afl-fuzz binary tool (just main() and usage())
+- `afl-fuzz-bitmap.c`	- afl-fuzz bitmap handling
+- `afl-fuzz-extras.c`	- afl-fuzz the *extra* function calls
+- `afl-fuzz-state.c`	- afl-fuzz state and globals
+- `afl-fuzz-init.c`		- afl-fuzz initialization
+- `afl-fuzz-misc.c`		- afl-fuzz misc functions
+- `afl-fuzz-one.c`          - afl-fuzz fuzzer_one big loop, this is where the mutation is happening
+- `afl-fuzz-python.c`	- afl-fuzz the python mutator extension
+- `afl-fuzz-queue.c`	- afl-fuzz handling the queue
+- `afl-fuzz-run.c`		- afl-fuzz running the target
+- `afl-fuzz-stats.c`	- afl-fuzz writing the statistics file
+- `afl-gcc.c`		- afl-gcc binary tool (deprecated)
+- `afl-common.c`		- common functions, used by afl-analyze, afl-fuzz, afl-showmap and afl-tmin
+- `afl-forkserver.c`	- forkserver implementation, used by afl-fuzz and afl-tmin
+afl-sharedmem.c		- sharedmem implementation, used by afl-fuzz and afl-tmin
diff --git a/src/README.src b/src/README.src
deleted file mode 100644
index 244f5ddd..00000000
--- a/src/README.src
+++ /dev/null
@@ -1,22 +0,0 @@
-Quick explanation about the files here:
-
-afl-analyze.c		- afl-analyze binary tool
-afl-as.c		- afl-as binary tool
-afl-gotcpu.c		- afl-gotcpu binary tool
-afl-showmap.c		- afl-showmap binary tool
-afl-tmin.c		- afl-tmin binary tool
-afl-fuzz.c		- afl-fuzz binary tool (just main() and usage())
-afl-fuzz-bitmap.c	- afl-fuzz bitmap handling
-afl-fuzz-extras.c	- afl-fuzz the *extra* function calls
-afl-fuzz-globals.c	- afl-fuzz global variables
-afl-fuzz-init.c		- afl-fuzz initialization
-afl-fuzz-misc.c		- afl-fuzz misc functions
-afl-fuzz-one.c          - afl-fuzz fuzzer_one big loop, this is where the mutation is happening
-afl-fuzz-python.c	- afl-fuzz the python mutator extension
-afl-fuzz-queue.c	- afl-fuzz handling the queue
-afl-fuzz-run.c		- afl-fuzz running the target
-afl-fuzz-stats.c	- afl-fuzz writing the statistics file
-afl-gcc.c		- afl-gcc binary tool (deprecated)
-afl-common.c		- common functions, used by afl-analyze, afl-fuzz, afl-showmap and afl-tmin
-afl-forkserver.c	- forkserver implementation, used by afl-fuzz and afl-tmin
-afl-sharedmem.c		- sharedmem implementation, used by afl-fuzz and afl-tmin
diff --git a/src/afl-analyze.c b/src/afl-analyze.c
index 2148cdf0..510ec94a 100644
--- a/src/afl-analyze.c
+++ b/src/afl-analyze.c
@@ -36,6 +36,7 @@
 #include "hash.h"
 #include "sharedmem.h"
 #include "common.h"
+#include "forkserver.h"
 
 #include <stdio.h>
 #include <unistd.h>
@@ -57,11 +58,10 @@
 
 static s32 child_pid;                  /* PID of the tested program         */
 
-u8 *trace_bits;                        /* SHM with instrumentation bitmap   */
+static u8 *trace_bits;                 /* SHM with instrumentation bitmap   */
 
 static u8 *in_file,                    /* Analyzer input test case          */
-    *prog_in,                          /* Targeted program input file       */
-    *doc_path;                         /* Path to docs                      */
+    *prog_in;                          /* Targeted program input file       */
 
 static u8 *in_data;                    /* Input data for analysis           */
 
@@ -75,16 +75,15 @@ static u64 mem_limit = MEM_LIMIT;      /* Memory limit (MB)                 */
 
 static s32 dev_null_fd = -1;           /* FD to /dev/null                   */
 
-u8 edges_only,                         /* Ignore hit counts?                */
+static u8 edges_only,                  /* Ignore hit counts?                */
     use_hex_offsets,                   /* Show hex offsets?                 */
-    be_quiet, use_stdin = 1;           /* Use stdin for program input?      */
+    use_stdin = 1;                     /* Use stdin for program input?      */
 
 static volatile u8 stop_soon,          /* Ctrl-C pressed?                   */
     child_timed_out;                   /* Child timed out?                  */
 
-static u8 qemu_mode;
-
 static u8 *target_path;
+static u8  qemu_mode;
 
 /* Constants used for describing byte behavior. */
 
@@ -207,15 +206,6 @@ static s32 write_to_file(u8 *path, u8 *mem, u32 len) {
 
 }
 
-/* Handle timeout signal. */
-
-static void handle_timeout(int sig) {
-
-  child_timed_out = 1;
-  if (child_pid > 0) kill(child_pid, SIGKILL);
-
-}
-
 /* Execute target application. Returns exec checksum, or 0 if program
    times out. */
 
@@ -770,11 +760,6 @@ static void setup_signal_handlers(void) {
   sigaction(SIGINT, &sa, NULL);
   sigaction(SIGTERM, &sa, NULL);
 
-  /* Exec timeout notifications. */
-
-  sa.sa_handler = handle_timeout;
-  sigaction(SIGALRM, &sa, NULL);
-
 }
 
 /* Display usage hints. */
diff --git a/src/afl-common.c b/src/afl-common.c
index 1aa15442..7eba6ae4 100644
--- a/src/afl-common.c
+++ b/src/afl-common.c
@@ -30,6 +30,7 @@
 #include "debug.h"
 #include "alloc-inl.h"
 #include "envs.h"
+#include "common.h"
 
 /* Detect @@ in args. */
 #ifndef __glibc__
@@ -37,8 +38,11 @@
 #endif
 #include <limits.h>
 
-extern u8 be_quiet;
-char *    afl_environment_variables[] = {
+u8  be_quiet = 0;
+u8 *doc_path = "";
+u8  last_intr = 0;
+
+char *afl_environment_variables[] = {
 
     "AFL_ALIGNED_ALLOC", "AFL_ALLOW_TMP", "AFL_ANALYZE_HEX", "AFL_AS",
     "AFL_AUTORESUME", "AFL_AS_FORCE_INSTRUMENT", "AFL_BENCH_JUST_ONE",
@@ -54,10 +58,12 @@ char *    afl_environment_variables[] = {
     "AFL_INST_LIBS", "AFL_INST_RATIO", "AFL_KEEP_TRACES", "AFL_KEEP_ASSEMBLY",
     "AFL_LD_HARD_FAIL", "AFL_LD_LIMIT_MB", "AFL_LD_NO_CALLOC_OVER",
     "AFL_LD_PRELOAD", "AFL_LD_VERBOSE", "AFL_LLVM_CMPLOG", "AFL_LLVM_INSTRIM",
-    "AFL_LLVM_INSTRIM_LOOPHEAD", "AFL_LLVM_INSTRIM_SKIPSINGLEBLOCK",
-    "AFL_LLVM_LAF_SPLIT_COMPARES", "AFL_LLVM_LAF_SPLIT_COMPARES_BITW",
-    "AFL_LLVM_LAF_SPLIT_FLOATS", "AFL_LLVM_LAF_SPLIT_SWITCHES",
-    "AFL_LLVM_LAF_TRANSFORM_COMPARES", "AFL_LLVM_NOT_ZERO",
+    "AFL_LLVM_CTX", "AFL_LLVM_INSTRUMENT", "AFL_LLVM_INSTRIM_LOOPHEAD",
+    "AFL_LLVM_LTO_AUTODICTIONARY", "AFL_LLVM_AUTODICTIONARY",
+    "AFL_LLVM_INSTRIM_SKIPSINGLEBLOCK", "AFL_LLVM_LAF_SPLIT_COMPARES",
+    "AFL_LLVM_LAF_SPLIT_COMPARES_BITW", "AFL_LLVM_LAF_SPLIT_FLOATS",
+    "AFL_LLVM_LAF_SPLIT_SWITCHES", "AFL_LLVM_LAF_TRANSFORM_COMPARES",
+    "AFL_LLVM_NGRAM_SIZE", "AFL_NGRAM_SIZE", "AFL_LLVM_NOT_ZERO",
     "AFL_LLVM_WHITELIST", "AFL_NO_AFFINITY", "AFL_LLVM_LTO_STARTID",
     "AFL_LLVM_LTO_DONTWRITEID", "AFL_NO_ARITH", "AFL_NO_BUILTIN",
     "AFL_NO_CPU_RED", "AFL_NO_FORKSRV", "AFL_NO_UI",
@@ -73,7 +79,8 @@ char *    afl_environment_variables[] = {
     "AFL_SHUFFLE_QUEUE", "AFL_SKIP_BIN_CHECK", "AFL_SKIP_CPUFREQ",
     "AFL_SKIP_CRASHES", "AFL_TMIN_EXACT", "AFL_TMPDIR", "AFL_TOKEN_FILE",
     "AFL_TRACE_PC", "AFL_USE_ASAN", "AFL_USE_MSAN", "AFL_USE_TRACE_PC",
-    "AFL_USE_UBSAN", "AFL_WINE_PATH", NULL};
+    "AFL_USE_UBSAN", "AFL_USE_CFISAN", "AFL_WINE_PATH", "AFL_NO_SNAPSHOT",
+    NULL};
 
 void detect_file_args(char **argv, u8 *prog_in, u8 *use_stdin) {
 
@@ -134,7 +141,7 @@ void detect_file_args(char **argv, u8 *prog_in, u8 *use_stdin) {
 
 char **argv_cpy_dup(int argc, char **argv) {
 
-  u32 i = 0;
+  int i = 0;
 
   char **ret = ck_alloc((argc + 1) * sizeof(char *));
 
@@ -228,7 +235,7 @@ char **get_qemu_argv(u8 *own_loc, u8 **target_path_p, int argc, char **argv) {
        "Oops, unable to find the 'afl-qemu-trace' binary. The binary must be "
        "built\n"
        "    separately by following the instructions in "
-       "afl->qemu_mode/README.md. "
+       "qemu_mode/README.md. "
        "If you\n"
        "    already have the binary installed, you may need to specify "
        "AFL_PATH in the\n"
@@ -325,7 +332,7 @@ char **get_wine_argv(u8 *own_loc, u8 **target_path_p, int argc, char **argv) {
        "Oops, unable to find the '%s' binary. The binary must be "
        "built\n"
        "    separately by following the instructions in "
-       "afl->qemu_mode/README.md. "
+       "qemu_mode/README.md. "
        "If you\n"
        "    already have the binary installed, you may need to specify "
        "AFL_PATH in the\n"
@@ -348,7 +355,7 @@ void check_environment_vars(char **envp) {
   if (be_quiet) return;
 
   int   index = 0, found = 0;
-  char *env;
+  char *env, *val;
   while ((env = envp[index++]) != NULL) {
 
     if (strncmp(env, "ALF_", 4) == 0) {
@@ -362,10 +369,21 @@ void check_environment_vars(char **envp) {
       while (match == 0 && afl_environment_variables[i] != NULL)
         if (strncmp(env, afl_environment_variables[i],
                     strlen(afl_environment_variables[i])) == 0 &&
-            env[strlen(afl_environment_variables[i])] == '=')
+            env[strlen(afl_environment_variables[i])] == '=') {
+
           match = 1;
-        else
+          if ((val = getenv(afl_environment_variables[i])) && !*val)
+            WARNF(
+                "AFL environment variable %s defined but is empty, this can "
+                "lead to unexpected consequences",
+                afl_environment_variables[i]);
+
+        } else {
+
           i++;
+
+        }
+
       if (match == 0) {
 
         WARNF("Mistyped AFL environment variable: %s", env);
@@ -393,3 +411,394 @@ char *get_afl_env(char *env) {
 
 }
 
+u64 get_cur_time(void) {
+
+  struct timeval  tv;
+  struct timezone tz;
+
+  gettimeofday(&tv, &tz);
+
+  return (tv.tv_sec * 1000ULL) + (tv.tv_usec / 1000);
+
+}
+
+/* Get unix time in microseconds */
+
+u64 get_cur_time_us(void) {
+
+  struct timeval  tv;
+  struct timezone tz;
+
+  gettimeofday(&tv, &tz);
+
+  return (tv.tv_sec * 1000000ULL) + tv.tv_usec;
+
+}
+
+/* Describe integer. The buf should be
+   at least 6 bytes to fit all ints we randomly see.
+   Will return buf for convenience. */
+
+u8 *stringify_int(u8 *buf, size_t len, u64 val) {
+\
+#define CHK_FORMAT(_divisor, _limit_mult, _fmt, _cast)     \
+  do {                                                     \
+                                                           \
+    if (val < (_divisor) * (_limit_mult)) {                \
+                                                           \
+      snprintf(buf, len, _fmt, ((_cast)val) / (_divisor)); \
+      return buf;                                          \
+                                                           \
+    }                                                      \
+                                                           \
+  } while (0)
+
+  /* 0-9999 */
+  CHK_FORMAT(1, 10000, "%llu", u64);
+
+  /* 10.0k - 99.9k */
+  CHK_FORMAT(1000, 99.95, "%0.01fk", double);
+
+  /* 100k - 999k */
+  CHK_FORMAT(1000, 1000, "%lluk", u64);
+
+  /* 1.00M - 9.99M */
+  CHK_FORMAT(1000 * 1000, 9.995, "%0.02fM", double);
+
+  /* 10.0M - 99.9M */
+  CHK_FORMAT(1000 * 1000, 99.95, "%0.01fM", double);
+
+  /* 100M - 999M */
+  CHK_FORMAT(1000 * 1000, 1000, "%lluM", u64);
+
+  /* 1.00G - 9.99G */
+  CHK_FORMAT(1000LL * 1000 * 1000, 9.995, "%0.02fG", double);
+
+  /* 10.0G - 99.9G */
+  CHK_FORMAT(1000LL * 1000 * 1000, 99.95, "%0.01fG", double);
+
+  /* 100G - 999G */
+  CHK_FORMAT(1000LL * 1000 * 1000, 1000, "%lluG", u64);
+
+  /* 1.00T - 9.99G */
+  CHK_FORMAT(1000LL * 1000 * 1000 * 1000, 9.995, "%0.02fT", double);
+
+  /* 10.0T - 99.9T */
+  CHK_FORMAT(1000LL * 1000 * 1000 * 1000, 99.95, "%0.01fT", double);
+
+  /* 100T+ */
+  strncpy(buf, "infty", len);
+  buf[len - 1] = '\0';
+
+  return buf;
+
+}
+
+/* Describe float. Similar as int. */
+
+u8 *stringify_float(u8 *buf, size_t len, double val) {
+
+  if (val < 99.995) {
+
+    snprintf(buf, len, "%0.02f", val);
+
+  } else if (val < 999.95) {
+
+    snprintf(buf, len, "%0.01f", val);
+
+  } else {
+
+    stringify_int(buf, len, (u64)val);
+
+  }
+
+  return buf;
+
+}
+
+/* Describe integer as memory size. */
+
+u8 *stringify_mem_size(u8 *buf, size_t len, u64 val) {
+
+  /* 0-9999 */
+  CHK_FORMAT(1, 10000, "%llu B", u64);
+
+  /* 10.0k - 99.9k */
+  CHK_FORMAT(1024, 99.95, "%0.01f kB", double);
+
+  /* 100k - 999k */
+  CHK_FORMAT(1024, 1000, "%llu kB", u64);
+
+  /* 1.00M - 9.99M */
+  CHK_FORMAT(1024 * 1024, 9.995, "%0.02f MB", double);
+
+  /* 10.0M - 99.9M */
+  CHK_FORMAT(1024 * 1024, 99.95, "%0.01f MB", double);
+
+  /* 100M - 999M */
+  CHK_FORMAT(1024 * 1024, 1000, "%llu MB", u64);
+
+  /* 1.00G - 9.99G */
+  CHK_FORMAT(1024LL * 1024 * 1024, 9.995, "%0.02f GB", double);
+
+  /* 10.0G - 99.9G */
+  CHK_FORMAT(1024LL * 1024 * 1024, 99.95, "%0.01f GB", double);
+
+  /* 100G - 999G */
+  CHK_FORMAT(1024LL * 1024 * 1024, 1000, "%llu GB", u64);
+
+  /* 1.00T - 9.99G */
+  CHK_FORMAT(1024LL * 1024 * 1024 * 1024, 9.995, "%0.02f TB", double);
+
+  /* 10.0T - 99.9T */
+  CHK_FORMAT(1024LL * 1024 * 1024 * 1024, 99.95, "%0.01f TB", double);
+
+#undef CHK_FORMAT
+
+  /* 100T+ */
+  strncpy(buf, "infty", len - 1);
+  buf[len - 1] = '\0';
+
+  return buf;
+
+}
+
+/* Describe time delta as string.
+   Returns a pointer to buf for convenience. */
+
+u8 *stringify_time_diff(u8 *buf, size_t len, u64 cur_ms, u64 event_ms) {
+
+  u64 delta;
+  s32 t_d, t_h, t_m, t_s;
+  u8  val_buf[STRINGIFY_VAL_SIZE_MAX];
+
+  if (!event_ms) {
+
+    snprintf(buf, len, "none seen yet");
+
+  } else {
+
+    delta = cur_ms - event_ms;
+
+    t_d = delta / 1000 / 60 / 60 / 24;
+    t_h = (delta / 1000 / 60 / 60) % 24;
+    t_m = (delta / 1000 / 60) % 60;
+    t_s = (delta / 1000) % 60;
+
+    stringify_int(val_buf, sizeof(val_buf), t_d);
+    snprintf(buf, len, "%s days, %d hrs, %d min, %d sec", val_buf, t_h, t_m,
+             t_s);
+
+  }
+
+  return buf;
+
+}
+
+/* Unsafe Describe integer. The buf sizes are not checked.
+   This is unsafe but fast.
+   Will return buf for convenience. */
+
+u8 *u_stringify_int(u8 *buf, u64 val) {
+\
+#define CHK_FORMAT(_divisor, _limit_mult, _fmt, _cast) \
+  do {                                                 \
+                                                       \
+    if (val < (_divisor) * (_limit_mult)) {            \
+                                                       \
+      sprintf(buf, _fmt, ((_cast)val) / (_divisor));   \
+      return buf;                                      \
+                                                       \
+    }                                                  \
+                                                       \
+  } while (0)
+
+  /* 0-9999 */
+  CHK_FORMAT(1, 10000, "%llu", u64);
+
+  /* 10.0k - 99.9k */
+  CHK_FORMAT(1000, 99.95, "%0.01fk", double);
+
+  /* 100k - 999k */
+  CHK_FORMAT(1000, 1000, "%lluk", u64);
+
+  /* 1.00M - 9.99M */
+  CHK_FORMAT(1000 * 1000, 9.995, "%0.02fM", double);
+
+  /* 10.0M - 99.9M */
+  CHK_FORMAT(1000 * 1000, 99.95, "%0.01fM", double);
+
+  /* 100M - 999M */
+  CHK_FORMAT(1000 * 1000, 1000, "%lluM", u64);
+
+  /* 1.00G - 9.99G */
+  CHK_FORMAT(1000LL * 1000 * 1000, 9.995, "%0.02fG", double);
+
+  /* 10.0G - 99.9G */
+  CHK_FORMAT(1000LL * 1000 * 1000, 99.95, "%0.01fG", double);
+
+  /* 100G - 999G */
+  CHK_FORMAT(1000LL * 1000 * 1000, 1000, "%lluG", u64);
+
+  /* 1.00T - 9.99G */
+  CHK_FORMAT(1000LL * 1000 * 1000 * 1000, 9.995, "%0.02fT", double);
+
+  /* 10.0T - 99.9T */
+  CHK_FORMAT(1000LL * 1000 * 1000 * 1000, 99.95, "%0.01fT", double);
+
+  /* 100T+ */
+  strcpy(buf, "infty");
+
+  return buf;
+
+}
+
+/* Unsafe describe float. Similar as unsafe int. */
+
+u8 *u_stringify_float(u8 *buf, double val) {
+
+  if (val < 99.995) {
+
+    sprintf(buf, "%0.02f", val);
+
+  } else if (val < 999.95) {
+
+    sprintf(buf, "%0.01f", val);
+
+  } else {
+
+    return u_stringify_int(buf, (u64)val);
+
+  }
+
+  return buf;
+
+}
+
+/* Unsafe describe integer as memory size. */
+
+u8 *u_stringify_mem_size(u8 *buf, u64 val) {
+
+  /* 0-9999 */
+  CHK_FORMAT(1, 10000, "%llu B", u64);
+
+  /* 10.0k - 99.9k */
+  CHK_FORMAT(1024, 99.95, "%0.01f kB", double);
+
+  /* 100k - 999k */
+  CHK_FORMAT(1024, 1000, "%llu kB", u64);
+
+  /* 1.00M - 9.99M */
+  CHK_FORMAT(1024 * 1024, 9.995, "%0.02f MB", double);
+
+  /* 10.0M - 99.9M */
+  CHK_FORMAT(1024 * 1024, 99.95, "%0.01f MB", double);
+
+  /* 100M - 999M */
+  CHK_FORMAT(1024 * 1024, 1000, "%llu MB", u64);
+
+  /* 1.00G - 9.99G */
+  CHK_FORMAT(1024LL * 1024 * 1024, 9.995, "%0.02f GB", double);
+
+  /* 10.0G - 99.9G */
+  CHK_FORMAT(1024LL * 1024 * 1024, 99.95, "%0.01f GB", double);
+
+  /* 100G - 999G */
+  CHK_FORMAT(1024LL * 1024 * 1024, 1000, "%llu GB", u64);
+
+  /* 1.00T - 9.99G */
+  CHK_FORMAT(1024LL * 1024 * 1024 * 1024, 9.995, "%0.02f TB", double);
+
+  /* 10.0T - 99.9T */
+  CHK_FORMAT(1024LL * 1024 * 1024 * 1024, 99.95, "%0.01f TB", double);
+
+#undef CHK_FORMAT
+
+  /* 100T+ */
+  strcpy(buf, "infty");
+
+  return buf;
+
+}
+
+/* Unsafe describe time delta as string.
+   Returns a pointer to buf for convenience. */
+
+u8 *u_stringify_time_diff(u8 *buf, u64 cur_ms, u64 event_ms) {
+
+  u64 delta;
+  s32 t_d, t_h, t_m, t_s;
+  u8  val_buf[STRINGIFY_VAL_SIZE_MAX];
+
+  if (!event_ms) {
+
+    sprintf(buf, "none seen yet");
+
+  } else {
+
+    delta = cur_ms - event_ms;
+
+    t_d = delta / 1000 / 60 / 60 / 24;
+    t_h = (delta / 1000 / 60 / 60) % 24;
+    t_m = (delta / 1000 / 60) % 60;
+    t_s = (delta / 1000) % 60;
+
+    u_stringify_int(val_buf, t_d);
+    sprintf(buf, "%s days, %d hrs, %d min, %d sec", val_buf, t_h, t_m, t_s);
+
+  }
+
+  return buf;
+
+}
+
+/* Wrapper for select() and read(), reading exactly len bytes.
+  Returns the time passed to read.
+  If the wait times out, returns timeout_ms + 1;
+  Returns 0 if an error occurred (fd closed, signal, ...); */
+u32 read_timed(s32 fd, void *buf, size_t len, u32 timeout_ms,
+               volatile u8 *stop_soon_p) {
+
+  struct timeval timeout;
+  fd_set         readfds;
+  FD_ZERO(&readfds);
+  FD_SET(fd, &readfds);
+
+  timeout.tv_sec = (timeout_ms / 1000);
+  timeout.tv_usec = (timeout_ms % 1000) * 1000;
+
+  size_t read_total = 0;
+  size_t len_read = 0;
+
+  while (len_read < len) {
+
+    /* set exceptfds as well to return when a child exited/closed the pipe. */
+    int sret = select(fd + 1, &readfds, NULL, NULL, &timeout);
+
+    if (!sret) {
+
+      // printf("Timeout in sret.");
+      return timeout_ms + 1;
+
+    } else if (sret < 0) {
+
+      /* Retry select for all signals other than than ctrl+c */
+      if (errno == EINTR && !*stop_soon_p) { continue; }
+      return 0;
+
+    }
+
+    len_read = read(fd, ((u8 *)buf) + len_read, len - len_read);
+    if (!len_read) { return 0; }
+    read_total += len_read;
+
+  }
+
+  s32 exec_ms =
+      MIN(timeout_ms,
+          ((u64)timeout_ms - (timeout.tv_sec * 1000 + timeout.tv_usec / 1000)));
+  return exec_ms > 0 ? exec_ms
+                     : 1;  // at least 1 milli must have passed (0 is an error)
+
+}
+
diff --git a/src/afl-forkserver.c b/src/afl-forkserver.c
index c7a3475f..28f664fa 100644
--- a/src/afl-forkserver.c
+++ b/src/afl-forkserver.c
@@ -49,90 +49,11 @@
 
 /* Describe integer as memory size. */
 
-extern u8 *doc_path;
-
-u8 *forkserver_DMS(u64 val) {
-
-  static u8 tmp[12][16];
-  static u8 cur;
-
-#define CHK_FORMAT(_divisor, _limit_mult, _fmt, _cast)    \
-  do {                                                    \
-                                                          \
-    if (val < (_divisor) * (_limit_mult)) {               \
-                                                          \
-      sprintf(tmp[cur], _fmt, ((_cast)val) / (_divisor)); \
-      return tmp[cur];                                    \
-                                                          \
-    }                                                     \
-                                                          \
-  } while (0)
-
-  cur = (cur + 1) % 12;
-
-  /* 0-9999 */
-  CHK_FORMAT(1, 10000, "%llu B", u64);
-
-  /* 10.0k - 99.9k */
-  CHK_FORMAT(1024, 99.95, "%0.01f kB", double);
-
-  /* 100k - 999k */
-  CHK_FORMAT(1024, 1000, "%llu kB", u64);
-
-  /* 1.00M - 9.99M */
-  CHK_FORMAT(1024 * 1024, 9.995, "%0.02f MB", double);
-
-  /* 10.0M - 99.9M */
-  CHK_FORMAT(1024 * 1024, 99.95, "%0.01f MB", double);
-
-  /* 100M - 999M */
-  CHK_FORMAT(1024 * 1024, 1000, "%llu MB", u64);
-
-  /* 1.00G - 9.99G */
-  CHK_FORMAT(1024LL * 1024 * 1024, 9.995, "%0.02f GB", double);
-
-  /* 10.0G - 99.9G */
-  CHK_FORMAT(1024LL * 1024 * 1024, 99.95, "%0.01f GB", double);
-
-  /* 100G - 999G */
-  CHK_FORMAT(1024LL * 1024 * 1024, 1000, "%llu GB", u64);
-
-  /* 1.00T - 9.99G */
-  CHK_FORMAT(1024LL * 1024 * 1024 * 1024, 9.995, "%0.02f TB", double);
-
-  /* 10.0T - 99.9T */
-  CHK_FORMAT(1024LL * 1024 * 1024 * 1024, 99.95, "%0.01f TB", double);
-
-#undef CHK_FORMAT
-
-  /* 100T+ */
-  strcpy(tmp[cur], "infty");
-  return tmp[cur];
-
-}
-
 list_t fsrv_list = {.element_prealloc_count = 0};
 
-/* the timeout handler */
-
-void handle_timeout(int sig) {
-
-  LIST_FOREACH(&fsrv_list, afl_forkserver_t, {
-
-    // TODO: We need a proper timer to handle multiple timeouts
-    if (el->child_pid > 0) {
+static void fsrv_exec_child(afl_forkserver_t *fsrv, char **argv) {
 
-      el->child_timed_out = 1;
-      kill(el->child_pid, SIGKILL);
-
-    } else if (el->child_pid == -1 && el->fsrv_pid > 0) {
-
-      el->child_timed_out = 1;
-      kill(el->fsrv_pid, SIGKILL);
-
-    }
-
-  });
+  execv(fsrv->target_path, argv);
 
 }
 
@@ -153,21 +74,51 @@ void afl_fsrv_init(afl_forkserver_t *fsrv) {
   fsrv->exec_tmout = EXEC_TIMEOUT;
   fsrv->mem_limit = MEM_LIMIT;
   fsrv->child_pid = -1;
-  fsrv->out_dir_fd = -1;
-
+  fsrv->map_size = MAP_SIZE;
   fsrv->use_fauxsrv = 0;
+  fsrv->prev_timed_out = 0;
+
+  fsrv->init_child_func = fsrv_exec_child;
 
   list_append(&fsrv_list, fsrv);
 
 }
 
+/* Initialize a new forkserver instance, duplicating "global" settings */
+void afl_fsrv_init_dup(afl_forkserver_t *fsrv_to, afl_forkserver_t *from) {
+
+  fsrv_to->use_stdin = from->use_stdin;
+  fsrv_to->dev_null_fd = from->dev_null_fd;
+  fsrv_to->exec_tmout = from->exec_tmout;
+  fsrv_to->mem_limit = from->mem_limit;
+  fsrv_to->map_size = from->map_size;
+
+#ifndef HAVE_ARC4RANDOM
+  fsrv_to->dev_urandom_fd = from->dev_urandom_fd;
+#endif
+
+  // These are forkserver specific.
+  fsrv_to->out_fd = -1;
+  fsrv_to->out_dir_fd = -1;
+  fsrv_to->child_pid = -1;
+  fsrv_to->use_fauxsrv = 0;
+  fsrv_to->prev_timed_out = 0;
+
+  fsrv_to->init_child_func = fsrv_exec_child;
+
+  list_append(&fsrv_list, fsrv_to);
+
+}
+
 /* Internal forkserver for dumb_mode=1 and non-forkserver mode runs.
   It execvs for each fork, forwarding exit codes and child pids to afl. */
 
 static void afl_fauxsrv_execv(afl_forkserver_t *fsrv, char **argv) {
 
-  static unsigned char tmp[4] = {0};
-  pid_t                child_pid = -1;
+  unsigned char tmp[4] = {0, 0, 0, 0};
+  pid_t         child_pid = -1;
+
+  if (!be_quiet) ACTF("Using Fauxserver:");
 
   /* Phone home and tell the parent that we're OK. If parent isn't there,
      assume we're not running in forkserver mode and just execute program. */
@@ -244,16 +195,25 @@ static void afl_fauxsrv_execv(afl_forkserver_t *fsrv, char **argv) {
    cloning a stopped child. So, we just execute once, and then send commands
    through a pipe. The other part of this logic is in afl-as.h / llvm_mode */
 
-void afl_fsrv_start(afl_forkserver_t *fsrv, char **argv) {
+void afl_fsrv_start(afl_forkserver_t *fsrv, char **argv,
+                    volatile u8 *stop_soon_p, u8 debug_child_output) {
+
+  int st_pipe[2], ctl_pipe[2];
+  int status;
+  s32 rlen;
+
+  if (!be_quiet) ACTF("Spinning up the fork server...");
+
+  if (fsrv->use_fauxsrv) {
 
-  struct timeval timeout;
-  int            st_pipe[2], ctl_pipe[2];
-  int            status;
-  s32            rlen;
+    /* TODO: Come up with sone nice way to initalize this all */
 
-  if (fsrv->use_fauxsrv) ACTF("Using Fauxserver:");
+    if (fsrv->init_child_func != fsrv_exec_child)
+      FATAL("Different forkserver not compatible with fauxserver");
 
-  if (!getenv("AFL_QUIET")) ACTF("Spinning up the fork server...");
+    fsrv->init_child_func = afl_fauxsrv_execv;
+
+  }
 
   if (pipe(st_pipe) || pipe(ctl_pipe)) PFATAL("pipe() failed");
 
@@ -305,7 +265,7 @@ void afl_fsrv_start(afl_forkserver_t *fsrv, char **argv) {
 
     setsid();
 
-    if (!get_afl_env("AFL_DEBUG_CHILD_OUTPUT")) {
+    if (!(debug_child_output)) {
 
       dup2(fsrv->dev_null_fd, 1);
       dup2(fsrv->dev_null_fd, 2);
@@ -338,7 +298,7 @@ void afl_fsrv_start(afl_forkserver_t *fsrv, char **argv) {
 #ifndef HAVE_ARC4RANDOM
     close(fsrv->dev_urandom_fd);
 #endif
-    close(fsrv->plot_file == NULL ? -1 : fileno(fsrv->plot_file));
+    if (fsrv->plot_file != NULL) fclose(fsrv->plot_file);
 
     /* This should improve performance a bit, since it stops the linker from
        doing extra work post-fork(). */
@@ -367,15 +327,7 @@ void afl_fsrv_start(afl_forkserver_t *fsrv, char **argv) {
            "msan_track_origins=0",
            0);
 
-    if (fsrv->use_fauxsrv) {
-
-      afl_fauxsrv_execv(fsrv, argv);
-
-    } else {
-
-      execv(fsrv->target_path, argv);
-
-    }
+    fsrv->init_child_func(fsrv, argv);
 
     /* Use a distinctive bitmap signature to tell the parent about execv()
        falling through. */
@@ -400,24 +352,22 @@ void afl_fsrv_start(afl_forkserver_t *fsrv, char **argv) {
   rlen = 0;
   if (fsrv->exec_tmout) {
 
-    fd_set readfds;
+    u32 time = read_timed(fsrv->fsrv_st_fd, &status, 4,
+                          fsrv->exec_tmout * FORK_WAIT_MULT, stop_soon_p);
 
-    FD_ZERO(&readfds);
-    FD_SET(fsrv->fsrv_st_fd, &readfds);
-    timeout.tv_sec = ((fsrv->exec_tmout * FORK_WAIT_MULT) / 1000);
-    timeout.tv_usec = ((fsrv->exec_tmout * FORK_WAIT_MULT) % 1000) * 1000;
+    if (!time) {
 
-    int sret = select(fsrv->fsrv_st_fd + 1, &readfds, NULL, NULL, &timeout);
+      kill(fsrv->fsrv_pid, SIGKILL);
 
-    if (sret == 0) {
+    } else if (time > fsrv->exec_tmout * FORK_WAIT_MULT) {
 
       fsrv->child_timed_out = 1;
-      kill(fsrv->child_pid, SIGKILL);
+      kill(fsrv->fsrv_pid, SIGKILL);
 
     } else {
-
-      rlen = read(fsrv->fsrv_st_fd, &status, 4);
-
+    
+      rlen = 4;
+    
     }
 
   } else {
@@ -431,7 +381,98 @@ void afl_fsrv_start(afl_forkserver_t *fsrv, char **argv) {
 
   if (rlen == 4) {
 
-    if (!getenv("AFL_QUIET")) OKF("All right - fork server is up.");
+    if (!be_quiet) OKF("All right - fork server is up.");
+
+    if ((status & FS_OPT_ENABLED) == FS_OPT_ENABLED) {
+
+      if (!be_quiet)
+        ACTF("Extended forkserver functions received (%08x).", status);
+
+      if ((status & FS_OPT_SNAPSHOT) == FS_OPT_SNAPSHOT) {
+
+        fsrv->snapshot = 1;
+        if (!be_quiet) ACTF("Using SNAPSHOT feature.");
+
+      }
+
+      if ((status & FS_OPT_MAPSIZE) == FS_OPT_MAPSIZE) {
+
+        fsrv->map_size = FS_OPT_GET_MAPSIZE(status);
+        if (fsrv->map_size % 8)  // should not happen
+          fsrv->map_size = (((fsrv->map_size + 8) >> 3) << 3);
+        if (!be_quiet) ACTF("Target map size: %u", fsrv->map_size);
+        if (fsrv->map_size > MAP_SIZE)
+          FATAL(
+              "Target's coverage map size of %u is larger than the one this "
+              "afl++ is compiled with (%u)\n",
+              fsrv->map_size, MAP_SIZE);
+
+      }
+
+      if ((status & FS_OPT_AUTODICT) == FS_OPT_AUTODICT) {
+
+        if (fsrv->function_ptr == NULL || fsrv->function_opt == NULL) {
+
+          // this is not afl-fuzz - we deny and return
+          status = (0xffffffff ^ (FS_OPT_ENABLED | FS_OPT_AUTODICT));
+          if (write(fsrv->fsrv_ctl_fd, &status, 4) != 4)
+            FATAL("Writing to forkserver failed.");
+          return;
+
+        }
+
+        if (!be_quiet) ACTF("Using AUTODICT feature.");
+        status = (FS_OPT_ENABLED | FS_OPT_AUTODICT);
+        if (write(fsrv->fsrv_ctl_fd, &status, 4) != 4)
+          FATAL("Writing to forkserver failed.");
+        if (read(fsrv->fsrv_st_fd, &status, 4) != 4)
+          FATAL("Reading from forkserver failed.");
+
+        if (status < 2 || (u32)status > 0xffffff)
+          FATAL("Dictionary has an illegal size: %d", status);
+
+        u32 len = status, offset = 0, count = 0;
+        u8 *dict = ck_alloc(len);
+        if (dict == NULL)
+          FATAL("Could not allocate %u bytes of autodictionary memmory", len);
+
+        while (len != 0) {
+
+          rlen = read(fsrv->fsrv_st_fd, dict + offset, len);
+          if (rlen > 0) {
+
+            len -= rlen;
+            offset += rlen;
+
+          } else {
+
+            FATAL(
+                "Reading autodictionary fail at position %u with %u bytes "
+                "left.",
+                offset, len);
+
+          }
+
+        }
+
+        len = status;
+        offset = 0;
+        while (offset < status && (u8)dict[offset] + offset < status) {
+
+          fsrv->function_ptr(fsrv->function_opt, dict + offset + 1,
+                             (u8)dict[offset]);
+          offset += (1 + dict[offset]);
+          count++;
+
+        }
+
+        if (!be_quiet) ACTF("Loaded %u autodictionary entries", count);
+        ck_free(dict);
+
+      }
+
+    }
+
     return;
 
   }
@@ -476,6 +517,8 @@ void afl_fsrv_start(afl_forkserver_t *fsrv, char **argv) {
 
     } else {
 
+      u8 val_buf[STRINGIFY_VAL_SIZE_MAX];
+
       SAYF("\n" cLRD "[-] " cRST
            "Whoops, the target binary crashed suddenly, "
            "before receiving any input\n"
@@ -508,7 +551,8 @@ void afl_fsrv_start(afl_forkserver_t *fsrv, char **argv) {
            "options\n"
            "      fail, poke <afl-users@googlegroups.com> for troubleshooting "
            "tips.\n",
-           forkserver_DMS(fsrv->mem_limit << 20), fsrv->mem_limit - 1);
+           stringify_mem_size(val_buf, sizeof(val_buf), fsrv->mem_limit << 20),
+           fsrv->mem_limit - 1);
 
     }
 
@@ -543,6 +587,8 @@ void afl_fsrv_start(afl_forkserver_t *fsrv, char **argv) {
 
   } else {
 
+    u8 val_buf[STRINGIFY_VAL_SIZE_MAX];
+
     SAYF(
         "\n" cLRD "[-] " cRST
         "Hmm, looks like the target binary terminated "
@@ -574,7 +620,8 @@ void afl_fsrv_start(afl_forkserver_t *fsrv, char **argv) {
               "never\n"
               "      reached before the program terminates.\n\n"
             : "",
-        forkserver_DMS(fsrv->mem_limit << 20), fsrv->mem_limit - 1);
+        stringify_int(val_buf, sizeof(val_buf), fsrv->mem_limit << 20),
+        fsrv->mem_limit - 1);
 
   }
 
@@ -582,11 +629,19 @@ void afl_fsrv_start(afl_forkserver_t *fsrv, char **argv) {
 
 }
 
+static void afl_fsrv_kill(afl_forkserver_t *fsrv) {
+
+    if (fsrv->child_pid > 0) kill(fsrv->child_pid, SIGKILL);
+    if (fsrv->fsrv_pid > 0) kill(fsrv->fsrv_pid, SIGKILL);
+    if (waitpid(fsrv->fsrv_pid, NULL, 0) <= 0) { WARNF("error waitpid\n"); }
+
+}
+
 void afl_fsrv_killall() {
 
   LIST_FOREACH(&fsrv_list, afl_forkserver_t, {
 
-    if (el->child_pid > 0) kill(el->child_pid, SIGKILL);
+    afl_fsrv_kill(el);
 
   });
 
@@ -594,6 +649,7 @@ void afl_fsrv_killall() {
 
 void afl_fsrv_deinit(afl_forkserver_t *fsrv) {
 
+  afl_fsrv_kill(fsrv);
   list_remove(&fsrv_list, fsrv);
 
 }
diff --git a/src/afl-fuzz-bitmap.c b/src/afl-fuzz-bitmap.c
index 7e2d3212..b6a494db 100644
--- a/src/afl-fuzz-bitmap.c
+++ b/src/afl-fuzz-bitmap.c
@@ -24,6 +24,7 @@
  */
 
 #include "afl-fuzz.h"
+#include <limits.h>
 
 /* Write bitmap to file. The bitmap is useful mostly for the secret
    -B option, to focus a separate fuzzing session on a particular
@@ -31,13 +32,13 @@
 
 void write_bitmap(afl_state_t *afl) {
 
-  u8 *fname;
+  u8  fname[PATH_MAX];
   s32 fd;
 
   if (!afl->bitmap_changed) return;
   afl->bitmap_changed = 0;
 
-  fname = alloc_printf("%s/fuzz_bitmap", afl->out_dir);
+  snprintf(fname, PATH_MAX, "%s/fuzz_bitmap", afl->out_dir);
   fd = open(fname, O_WRONLY | O_CREAT | O_TRUNC, 0600);
 
   if (fd < 0) PFATAL("Unable to open '%s'", fname);
@@ -45,7 +46,6 @@ void write_bitmap(afl_state_t *afl) {
   ck_write(fd, afl->virgin_bits, MAP_SIZE, fname);
 
   close(fd);
-  ck_free(fname);
 
 }
 
@@ -78,16 +78,17 @@ u8 has_new_bits(afl_state_t *afl, u8 *virgin_map) {
   u64 *current = (u64 *)afl->fsrv.trace_bits;
   u64 *virgin = (u64 *)virgin_map;
 
-  u32 i = (MAP_SIZE >> 3);
+  u32 i = (afl->fsrv.map_size >> 3);
 
 #else
 
   u32 *current = (u32 *)afl->fsrv.trace_bits;
   u32 *virgin = (u32 *)virgin_map;
 
-  u32 i = (MAP_SIZE >> 2);
+  u32 i = (afl->fsrv.map_size >> 2);
 
 #endif                                                     /* ^WORD_SIZE_64 */
+  if (i == 0) i = 1;
 
   u8 ret = 0;
 
@@ -138,7 +139,8 @@ u8 has_new_bits(afl_state_t *afl, u8 *virgin_map) {
 
   }
 
-  if (ret && virgin_map == afl->virgin_bits) afl->bitmap_changed = 1;
+  if (unlikely(ret) && unlikely(virgin_map == afl->virgin_bits))
+    afl->bitmap_changed = 1;
 
   return ret;
 
@@ -147,12 +149,14 @@ u8 has_new_bits(afl_state_t *afl, u8 *virgin_map) {
 /* Count the number of bits set in the provided bitmap. Used for the status
    screen several times every second, does not have to be fast. */
 
-u32 count_bits(u8 *mem) {
+u32 count_bits(afl_state_t *afl, u8 *mem) {
 
   u32 *ptr = (u32 *)mem;
-  u32  i = (MAP_SIZE >> 2);
+  u32  i = (afl->fsrv.map_size >> 2);
   u32  ret = 0;
 
+  if (i == 0) i = 1;
+
   while (i--) {
 
     u32 v = *(ptr++);
@@ -177,27 +181,27 @@ u32 count_bits(u8 *mem) {
 
 }
 
-#define FF(_b) (0xff << ((_b) << 3))
-
 /* Count the number of bytes set in the bitmap. Called fairly sporadically,
    mostly to update the status screen or calibrate and examine confirmed
    new paths. */
 
-u32 count_bytes(u8 *mem) {
+u32 count_bytes(afl_state_t *afl, u8 *mem) {
 
   u32 *ptr = (u32 *)mem;
-  u32  i = (MAP_SIZE >> 2);
+  u32  i = (afl->fsrv.map_size >> 2);
   u32  ret = 0;
 
+  if (i == 0) i = 1;
+
   while (i--) {
 
     u32 v = *(ptr++);
 
     if (!v) continue;
-    if (v & FF(0)) ++ret;
-    if (v & FF(1)) ++ret;
-    if (v & FF(2)) ++ret;
-    if (v & FF(3)) ++ret;
+    if (v & 0x000000ff) ++ret;
+    if (v & 0x0000ff00) ++ret;
+    if (v & 0x00ff0000) ++ret;
+    if (v & 0xff000000) ++ret;
 
   }
 
@@ -208,12 +212,14 @@ u32 count_bytes(u8 *mem) {
 /* Count the number of non-255 bytes set in the bitmap. Used strictly for the
    status screen, several calls per second or so. */
 
-u32 count_non_255_bytes(u8 *mem) {
+u32 count_non_255_bytes(afl_state_t *afl, u8 *mem) {
 
   u32 *ptr = (u32 *)mem;
-  u32  i = (MAP_SIZE >> 2);
+  u32  i = (afl->fsrv.map_size >> 2);
   u32  ret = 0;
 
+  if (i == 0) i = 1;
+
   while (i--) {
 
     u32 v = *(ptr++);
@@ -222,10 +228,10 @@ u32 count_non_255_bytes(u8 *mem) {
        case. */
 
     if (v == 0xffffffff) continue;
-    if ((v & FF(0)) != FF(0)) ++ret;
-    if ((v & FF(1)) != FF(1)) ++ret;
-    if ((v & FF(2)) != FF(2)) ++ret;
-    if ((v & FF(3)) != FF(3)) ++ret;
+    if ((v & 0x000000ff) != 0x000000ff) ++ret;
+    if ((v & 0x0000ff00) != 0x0000ff00) ++ret;
+    if ((v & 0x00ff0000) != 0x00ff0000) ++ret;
+    if ((v & 0xff000000) != 0xff000000) ++ret;
 
   }
 
@@ -246,9 +252,11 @@ const u8 simplify_lookup[256] = {
 
 #ifdef WORD_SIZE_64
 
-void simplify_trace(u64 *mem) {
+void simplify_trace(afl_state_t *afl, u64 *mem) {
 
-  u32 i = MAP_SIZE >> 3;
+  u32 i = (afl->fsrv.map_size >> 3);
+
+  if (i == 0) i = 1;
 
   while (i--) {
 
@@ -279,9 +287,11 @@ void simplify_trace(u64 *mem) {
 
 #else
 
-void simplify_trace(u32 *mem) {
+void simplify_trace(afl_state_t *afl, u32 *mem) {
+
+  u32 i = (afl->fsrv.map_size >> 2);
 
-  u32 i = MAP_SIZE >> 2;
+  if (i == 0) i = 1;
 
   while (i--) {
 
@@ -341,9 +351,11 @@ void init_count_class16(void) {
 
 #ifdef WORD_SIZE_64
 
-void classify_counts(u64 *mem) {
+void classify_counts(afl_state_t *afl, u64 *mem) {
+
+  u32 i = (afl->fsrv.map_size >> 3);
 
-  u32 i = MAP_SIZE >> 3;
+  if (i == 0) i = 1;
 
   while (i--) {
 
@@ -368,9 +380,11 @@ void classify_counts(u64 *mem) {
 
 #else
 
-void classify_counts(u32 *mem) {
+void classify_counts(afl_state_t *afl, u32 *mem) {
 
-  u32 i = MAP_SIZE >> 2;
+  u32 i = (afl->fsrv.map_size >> 2);
+
+  if (i == 0) i = 1;
 
   while (i--) {
 
@@ -397,11 +411,11 @@ void classify_counts(u32 *mem) {
    count information here. This is called only sporadically, for some
    new paths. */
 
-void minimize_bits(u8 *dst, u8 *src) {
+void minimize_bits(afl_state_t *afl, u8 *dst, u8 *src) {
 
   u32 i = 0;
 
-  while (i < MAP_SIZE) {
+  while (i < afl->fsrv.map_size) {
 
     if (*(src++)) dst[i >> 3] |= 1 << (i & 7);
     ++i;
@@ -413,13 +427,13 @@ void minimize_bits(u8 *dst, u8 *src) {
 #ifndef SIMPLE_FILES
 
 /* Construct a file name for a new test case, capturing the operation
-   that led to its discovery. Uses a static buffer. */
+   that led to its discovery. Returns a ptr to afl->describe_op_buf_256. */
 
 u8 *describe_op(afl_state_t *afl, u8 hnb) {
 
   u8 *ret = afl->describe_op_buf_256;
 
-  if (afl->syncing_party) {
+  if (unlikely(afl->syncing_party)) {
 
     sprintf(ret, "sync:%s,src:%06u", afl->syncing_party, afl->syncing_case);
 
@@ -461,20 +475,23 @@ u8 *describe_op(afl_state_t *afl, u8 hnb) {
 
 static void write_crash_readme(afl_state_t *afl) {
 
-  u8 *  fn = alloc_printf("%s/crashes/README.txt", afl->out_dir);
+  u8    fn[PATH_MAX];
   s32   fd;
   FILE *f;
 
+  u8 val_buf[STRINGIFY_VAL_SIZE_MAX];
+
+  sprintf(fn, "%s/crashes/README.txt", afl->out_dir);
+
   fd = open(fn, O_WRONLY | O_CREAT | O_EXCL, 0600);
-  ck_free(fn);
 
   /* Do not die on errors here - that would be impolite. */
 
-  if (fd < 0) return;
+  if (unlikely(fd < 0)) return;
 
   f = fdopen(fd, "w");
 
-  if (!f) {
+  if (unlikely(!f)) {
 
     close(fd);
     return;
@@ -501,7 +518,9 @@ static void write_crash_readme(afl_state_t *afl) {
 
       "  https://github.com/AFLplusplus/AFLplusplus\n\n",
 
-      afl->orig_cmdline, DMS(afl->fsrv.mem_limit << 20));  /* ignore errors */
+      afl->orig_cmdline,
+      stringify_mem_size(val_buf, sizeof(val_buf),
+                         afl->fsrv.mem_limit << 20));      /* ignore errors */
 
   fclose(f);
 
@@ -513,15 +532,17 @@ static void write_crash_readme(afl_state_t *afl) {
 
 u8 save_if_interesting(afl_state_t *afl, void *mem, u32 len, u8 fault) {
 
-  if (len == 0) return 0;
+  if (unlikely(len == 0)) return 0;
 
-  u8 *fn = "";
+  u8 *queue_fn = "";
   u8  hnb;
   s32 fd;
   u8  keeping = 0, res;
 
+  u8 fn[PATH_MAX];
+
   /* Update path frequency. */
-  u32 cksum = hash32(afl->fsrv.trace_bits, MAP_SIZE, HASH_CONST);
+  u32 cksum = hash32(afl->fsrv.trace_bits, afl->fsrv.map_size, HASH_CONST);
 
   struct queue_entry *q = afl->queue;
   while (q) {
@@ -537,30 +558,31 @@ u8 save_if_interesting(afl_state_t *afl, void *mem, u32 len, u8 fault) {
 
   }
 
-  if (fault == afl->crash_mode) {
+  if (unlikely(fault == afl->crash_mode)) {
 
     /* Keep only if there are new bits in the map, add to queue for
        future fuzzing, etc. */
 
     if (!(hnb = has_new_bits(afl, afl->virgin_bits))) {
 
-      if (afl->crash_mode) ++afl->total_crashes;
+      if (unlikely(afl->crash_mode)) ++afl->total_crashes;
       return 0;
 
     }
 
 #ifndef SIMPLE_FILES
 
-    fn = alloc_printf("%s/queue/id:%06u,%s", afl->out_dir, afl->queued_paths,
-                      describe_op(afl, hnb));
+    queue_fn = alloc_printf("%s/queue/id:%06u,%s", afl->out_dir,
+                            afl->queued_paths, describe_op(afl, hnb));
 
 #else
 
-    fn = alloc_printf("%s/queue/id_%06u", afl->out_dir, afl->queued_paths);
+    queue_fn =
+        alloc_printf("%s/queue/id_%06u", afl->out_dir, afl->queued_paths);
 
 #endif                                                    /* ^!SIMPLE_FILES */
 
-    add_to_queue(afl, fn, len, 0);
+    add_to_queue(afl, queue_fn, len, 0);
 
     if (hnb == 2) {
 
@@ -576,11 +598,12 @@ u8 save_if_interesting(afl_state_t *afl, void *mem, u32 len, u8 fault) {
 
     res = calibrate_case(afl, afl->queue_top, mem, afl->queue_cycle - 1, 0);
 
-    if (res == FAULT_ERROR) FATAL("Unable to execute target application");
+    if (unlikely(res == FAULT_ERROR))
+      FATAL("Unable to execute target application");
 
-    fd = open(fn, O_WRONLY | O_CREAT | O_EXCL, 0600);
-    if (fd < 0) PFATAL("Unable to create '%s'", fn);
-    ck_write(fd, mem, len, fn);
+    fd = open(queue_fn, O_WRONLY | O_CREAT | O_EXCL, 0600);
+    if (unlikely(fd < 0)) PFATAL("Unable to create '%s'", queue_fn);
+    ck_write(fd, mem, len, queue_fn);
     close(fd);
 
     keeping = 1;
@@ -600,12 +623,12 @@ u8 save_if_interesting(afl_state_t *afl, void *mem, u32 len, u8 fault) {
 
       if (afl->unique_hangs >= KEEP_UNIQUE_HANG) return keeping;
 
-      if (!afl->dumb_mode) {
+      if (likely(!afl->dumb_mode)) {
 
 #ifdef WORD_SIZE_64
-        simplify_trace((u64 *)afl->fsrv.trace_bits);
+        simplify_trace(afl, (u64 *)afl->fsrv.trace_bits);
 #else
-        simplify_trace((u32 *)afl->fsrv.trace_bits);
+        simplify_trace(afl, (u32 *)afl->fsrv.trace_bits);
 #endif                                                     /* ^WORD_SIZE_64 */
 
         if (!has_new_bits(afl, afl->virgin_tmout)) return keeping;
@@ -622,7 +645,7 @@ u8 save_if_interesting(afl_state_t *afl, void *mem, u32 len, u8 fault) {
 
         u8 new_fault;
         write_to_testcase(afl, mem, len);
-        new_fault = run_target(afl, afl->hang_tmout);
+        new_fault = run_target(afl, &afl->fsrv, afl->hang_tmout);
 
         /* A corner case that one user reported bumping into: increasing the
            timeout actually uncovers a crash. Make sure we don't discard it if
@@ -636,12 +659,13 @@ u8 save_if_interesting(afl_state_t *afl, void *mem, u32 len, u8 fault) {
 
 #ifndef SIMPLE_FILES
 
-      fn = alloc_printf("%s/hangs/id:%06llu,%s", afl->out_dir,
-                        afl->unique_hangs, describe_op(afl, 0));
+      snprintf(fn, PATH_MAX, "%s/hangs/id:%06llu,%s", afl->out_dir,
+               afl->unique_hangs, describe_op(afl, 0));
 
 #else
 
-      fn = alloc_printf("%s/hangs/id_%06llu", afl->out_dir, afl->unique_hangs);
+      snprintf(fn, PATH_MAX, "%s/hangs/id_%06llu", afl->out_dir,
+               afl->unique_hangs);
 
 #endif                                                    /* ^!SIMPLE_FILES */
 
@@ -663,38 +687,37 @@ u8 save_if_interesting(afl_state_t *afl, void *mem, u32 len, u8 fault) {
 
       if (afl->unique_crashes >= KEEP_UNIQUE_CRASH) return keeping;
 
-      if (!afl->dumb_mode) {
+      if (likely(!afl->dumb_mode)) {
 
 #ifdef WORD_SIZE_64
-        simplify_trace((u64 *)afl->fsrv.trace_bits);
+        simplify_trace(afl, (u64 *)afl->fsrv.trace_bits);
 #else
-        simplify_trace((u32 *)afl->fsrv.trace_bits);
+        simplify_trace(afl, (u32 *)afl->fsrv.trace_bits);
 #endif                                                     /* ^WORD_SIZE_64 */
 
         if (!has_new_bits(afl, afl->virgin_crash)) return keeping;
 
       }
 
-      if (!afl->unique_crashes) write_crash_readme(afl);
+      if (unlikely(!afl->unique_crashes)) write_crash_readme(afl);
 
 #ifndef SIMPLE_FILES
 
-      fn = alloc_printf("%s/crashes/id:%06llu,sig:%02u,%s", afl->out_dir,
-                        afl->unique_crashes, afl->kill_signal,
-                        describe_op(afl, 0));
+      snprintf(fn, PATH_MAX, "%s/crashes/id:%06llu,sig:%02u,%s", afl->out_dir,
+               afl->unique_crashes, afl->kill_signal, describe_op(afl, 0));
 
 #else
 
-      fn = alloc_printf("%s/crashes/id_%06llu_%02u", afl->out_dir,
-                        afl->unique_crashes, afl->kill_signal);
+      snprintf(fn, PATH_MAX, "%s/crashes/id_%06llu_%02u", afl->out_dir,
+               afl->unique_crashes, afl->kill_signal);
 
 #endif                                                    /* ^!SIMPLE_FILES */
 
       ++afl->unique_crashes;
-      if (afl->infoexec) {  // if the user wants to be informed on new crashes -
-                            // do
+      if (unlikely(afl->infoexec)) {
+
+        // if the user wants to be informed on new crashes - do that
 #if !TARGET_OS_IPHONE
-        // that
         if (system(afl->infoexec) == -1)
           hnb += 0;  // we dont care if system errors, but we dont want a
                      // compiler warning either
@@ -719,12 +742,10 @@ u8 save_if_interesting(afl_state_t *afl, void *mem, u32 len, u8 fault) {
      test case, too. */
 
   fd = open(fn, O_WRONLY | O_CREAT | O_EXCL, 0600);
-  if (fd < 0) PFATAL("Unable to create '%s'", fn);
+  if (unlikely(fd < 0)) PFATAL("Unable to create '%s'", fn);
   ck_write(fd, mem, len, fn);
   close(fd);
 
-  ck_free(fn);
-
   return keeping;
 
 }
diff --git a/src/afl-fuzz-cmplog.c b/src/afl-fuzz-cmplog.c
index 1600af53..e2747097 100644
--- a/src/afl-fuzz-cmplog.c
+++ b/src/afl-fuzz-cmplog.c
@@ -29,590 +29,18 @@
 #include "afl-fuzz.h"
 #include "cmplog.h"
 
-void init_cmplog_forkserver(afl_state_t *afl) {
+typedef struct cmplog_data {
 
-  static struct timeval timeout;
-  int                   st_pipe[2], ctl_pipe[2];
-  int                   status;
-  s32                   rlen;
+} cmplog_data_t;
 
-  ACTF("Spinning up the cmplog fork server...");
+void cmplog_exec_child(afl_forkserver_t *fsrv, char **argv) {
 
-  if (pipe(st_pipe) || pipe(ctl_pipe)) PFATAL("pipe() failed");
+  setenv("___AFL_EINS_ZWEI_POLIZEI___", "1", 1);
 
-  afl->fsrv.child_timed_out = 0;
-  afl->cmplog_fsrv_pid = fork();
+  if (!fsrv->qemu_mode && argv[0] != fsrv->cmplog_binary)
+    argv[0] = fsrv->cmplog_binary;
 
-  if (afl->cmplog_fsrv_pid < 0) PFATAL("fork() failed");
-
-  if (!afl->cmplog_fsrv_pid) {
-
-    /* CHILD PROCESS */
-
-    struct rlimit r;
-
-    /* Umpf. On OpenBSD, the default fd limit for root users is set to
-       soft 128. Let's try to fix that... */
-
-    if (!getrlimit(RLIMIT_NOFILE, &r) && r.rlim_cur < FORKSRV_FD + 2) {
-
-      r.rlim_cur = FORKSRV_FD + 2;
-      setrlimit(RLIMIT_NOFILE, &r);                        /* Ignore errors */
-
-    }
-
-    if (afl->fsrv.mem_limit) {
-
-      r.rlim_max = r.rlim_cur = ((rlim_t)afl->fsrv.mem_limit) << 20;
-
-#ifdef RLIMIT_AS
-      setrlimit(RLIMIT_AS, &r);                            /* Ignore errors */
-#else
-      /* This takes care of OpenBSD, which doesn't have RLIMIT_AS, but
-         according to reliable sources, RLIMIT_DATA covers anonymous
-         maps - so we should be getting good protection against OOM bugs. */
-
-      setrlimit(RLIMIT_DATA, &r);                          /* Ignore errors */
-#endif                                                        /* ^RLIMIT_AS */
-
-    }
-
-    /* Dumping cores is slow and can lead to anomalies if SIGKILL is delivered
-       before the dump is complete. */
-
-    //    r.rlim_max = r.rlim_cur = 0;
-    //    setrlimit(RLIMIT_CORE, &r);                      /* Ignore errors */
-
-    /* Isolate the process and configure standard descriptors. If
-       afl->fsrv.out_file is specified, stdin is /dev/null; otherwise,
-       afl->fsrv.out_fd is cloned instead. */
-
-    setsid();
-
-    if (!(afl->afl_env.afl_debug_child_output)) {
-
-      dup2(afl->fsrv.dev_null_fd, 1);
-      dup2(afl->fsrv.dev_null_fd, 2);
-
-    }
-
-    if (!afl->fsrv.use_stdin) {
-
-      dup2(afl->fsrv.dev_null_fd, 0);
-
-    } else {
-
-      dup2(afl->fsrv.out_fd, 0);
-      close(afl->fsrv.out_fd);
-
-    }
-
-    /* Set up control and status pipes, close the unneeded original fds. */
-
-    if (dup2(ctl_pipe[0], FORKSRV_FD) < 0) PFATAL("dup2() failed");
-    if (dup2(st_pipe[1], FORKSRV_FD + 1) < 0) PFATAL("dup2() failed");
-
-    close(ctl_pipe[0]);
-    close(ctl_pipe[1]);
-    close(st_pipe[0]);
-    close(st_pipe[1]);
-
-    close(afl->fsrv.out_dir_fd);
-    close(afl->fsrv.dev_null_fd);
-#ifndef HAVE_ARC4RANDOM
-    close(afl->fsrv.dev_urandom_fd);
-#endif
-    close(afl->fsrv.plot_file == NULL ? -1 : fileno(afl->fsrv.plot_file));
-
-    /* This should improve performance a bit, since it stops the linker from
-       doing extra work post-fork(). */
-
-    if (!getenv("LD_BIND_LAZY")) setenv("LD_BIND_NOW", "1", 0);
-
-    /* Set sane defaults for ASAN if nothing else specified. */
-
-    setenv("ASAN_OPTIONS",
-           "abort_on_error=1:"
-           "detect_leaks=0:"
-           "malloc_context_size=0:"
-           "symbolize=0:"
-           "allocator_may_return_null=1",
-           0);
-
-    /* MSAN is tricky, because it doesn't support abort_on_error=1 at this
-       point. So, we do this in a very hacky way. */
-
-    setenv("MSAN_OPTIONS",
-           "exit_code=" STRINGIFY(MSAN_ERROR) ":"
-           "symbolize=0:"
-           "abort_on_error=1:"
-           "malloc_context_size=0:"
-           "allocator_may_return_null=1:"
-           "msan_track_origins=0",
-           0);
-
-    setenv("___AFL_EINS_ZWEI_POLIZEI___", "1", 1);
-
-    if (!afl->qemu_mode && afl->argv[0] != afl->cmplog_binary) {
-
-      ck_free(afl->argv[0]);
-      afl->argv[0] = afl->cmplog_binary;
-
-    }
-
-    execv(afl->argv[0], afl->argv);
-
-    /* Use a distinctive bitmap signature to tell the parent about execv()
-       falling through. */
-
-    *(u32 *)afl->fsrv.trace_bits = EXEC_FAIL_SIG;
-    exit(0);
-
-  }
-
-  /* PARENT PROCESS */
-
-  /* Close the unneeded endpoints. */
-
-  close(ctl_pipe[0]);
-  close(st_pipe[1]);
-
-  afl->cmplog_fsrv_ctl_fd = ctl_pipe[1];
-  afl->cmplog_fsrv_st_fd = st_pipe[0];
-
-  /* Wait for the fork server to come up, but don't wait too long. */
-
-  rlen = 0;
-  if (afl->fsrv.exec_tmout) {
-
-    fd_set readfds;
-    FD_ZERO(&readfds);
-    FD_SET(afl->cmplog_fsrv_st_fd, &readfds);
-    timeout.tv_sec = ((afl->fsrv.exec_tmout * FORK_WAIT_MULT) / 1000);
-    timeout.tv_usec = ((afl->fsrv.exec_tmout * FORK_WAIT_MULT) % 1000) * 1000;
-
-    int sret =
-        select(afl->cmplog_fsrv_st_fd + 1, &readfds, NULL, NULL, &timeout);
-
-    if (sret == 0) {
-
-      kill(afl->cmplog_fsrv_pid, SIGKILL);
-
-    } else {
-
-      rlen = read(afl->cmplog_fsrv_st_fd, &status, 4);
-
-    }
-
-  } else {
-
-    rlen = read(afl->cmplog_fsrv_st_fd, &status, 4);
-
-  }
-
-  /* If we have a four-byte "hello" message from the server, we're all set.
-     Otherwise, try to figure out what went wrong. */
-
-  if (rlen == 4) {
-
-    OKF("All right - fork server is up.");
-    return;
-
-  }
-
-  if (afl->fsrv.child_timed_out)
-    FATAL(
-        "Timeout while initializing cmplog fork server (adjusting -t may "
-        "help)");
-
-  if (waitpid(afl->cmplog_fsrv_pid, &status, 0) <= 0)
-    PFATAL("waitpid() failed");
-
-  if (WIFSIGNALED(status)) {
-
-    if (afl->fsrv.mem_limit && afl->fsrv.mem_limit < 500 &&
-        afl->fsrv.uses_asan) {
-
-      SAYF("\n" cLRD "[-] " cRST
-           "Whoops, the target binary crashed suddenly, "
-           "before receiving any input\n"
-           "    from the fuzzer! Since it seems to be built with ASAN and you "
-           "have a\n"
-           "    restrictive memory limit configured, this is expected; please "
-           "read\n"
-           "    %s/notes_for_asan.md for help.\n",
-           doc_path);
-
-    } else if (!afl->fsrv.mem_limit) {
-
-      SAYF("\n" cLRD "[-] " cRST
-           "Whoops, the target binary crashed suddenly, "
-           "before receiving any input\n"
-           "    from the fuzzer! There are several probable explanations:\n\n"
-
-           "    - The binary is just buggy and explodes entirely on its own. "
-           "If so, you\n"
-           "      need to fix the underlying problem or find a better "
-           "replacement.\n\n"
-
-           MSG_FORK_ON_APPLE
-
-           "    - Less likely, there is a horrible bug in the fuzzer. If other "
-           "options\n"
-           "      fail, poke <afl-users@googlegroups.com> for troubleshooting "
-           "tips.\n");
-
-    } else {
-
-      SAYF("\n" cLRD "[-] " cRST
-           "Whoops, the target binary crashed suddenly, "
-           "before receiving any input\n"
-           "    from the fuzzer! There are several probable explanations:\n\n"
-
-           "    - The current memory limit (%s) is too restrictive, causing "
-           "the\n"
-           "      target to hit an OOM condition in the dynamic linker. Try "
-           "bumping up\n"
-           "      the limit with the -m setting in the command line. A simple "
-           "way confirm\n"
-           "      this diagnosis would be:\n\n"
-
-           MSG_ULIMIT_USAGE
-           " /path/to/fuzzed_app )\n\n"
-
-           "      Tip: you can use http://jwilk.net/software/recidivm to "
-           "quickly\n"
-           "      estimate the required amount of virtual memory for the "
-           "binary.\n\n"
-
-           "    - The binary is just buggy and explodes entirely on its own. "
-           "If so, you\n"
-           "      need to fix the underlying problem or find a better "
-           "replacement.\n\n"
-
-           MSG_FORK_ON_APPLE
-
-           "    - Less likely, there is a horrible bug in the fuzzer. If other "
-           "options\n"
-           "      fail, poke <afl-users@googlegroups.com> for troubleshooting "
-           "tips.\n",
-           DMS(afl->fsrv.mem_limit << 20), afl->fsrv.mem_limit - 1);
-
-    }
-
-    FATAL("Cmplog fork server crashed with signal %d", WTERMSIG(status));
-
-  }
-
-  if (*(u32 *)afl->fsrv.trace_bits == EXEC_FAIL_SIG)
-    FATAL("Unable to execute target application ('%s')", afl->argv[0]);
-
-  if (afl->fsrv.mem_limit && afl->fsrv.mem_limit < 500 && afl->fsrv.uses_asan) {
-
-    SAYF("\n" cLRD "[-] " cRST
-         "Hmm, looks like the target binary terminated "
-         "before we could complete a\n"
-         "    handshake with the injected code. Since it seems to be built "
-         "with ASAN and\n"
-         "    you have a restrictive memory limit configured, this is "
-         "expected; please\n"
-         "    read %s/notes_for_asan.md for help.\n",
-         doc_path);
-
-  } else if (!afl->fsrv.mem_limit) {
-
-    SAYF("\n" cLRD "[-] " cRST
-         "Hmm, looks like the target binary terminated "
-         "before we could complete a\n"
-         "    handshake with the injected code. Perhaps there is a horrible "
-         "bug in the\n"
-         "    fuzzer. Poke <afl-users@googlegroups.com> for troubleshooting "
-         "tips.\n");
-
-  } else {
-
-    SAYF(
-        "\n" cLRD "[-] " cRST
-        "Hmm, looks like the target binary terminated "
-        "before we could complete a\n"
-        "    handshake with the injected code. There are %s probable "
-        "explanations:\n\n"
-
-        "%s"
-        "    - The current memory limit (%s) is too restrictive, causing an "
-        "OOM\n"
-        "      fault in the dynamic linker. This can be fixed with the -m "
-        "option. A\n"
-        "      simple way to confirm the diagnosis may be:\n\n"
-
-        MSG_ULIMIT_USAGE
-        " /path/to/fuzzed_app )\n\n"
-
-        "      Tip: you can use http://jwilk.net/software/recidivm to quickly\n"
-        "      estimate the required amount of virtual memory for the "
-        "binary.\n\n"
-
-        "    - Less likely, there is a horrible bug in the fuzzer. If other "
-        "options\n"
-        "      fail, poke <afl-users@googlegroups.com> for troubleshooting "
-        "tips.\n",
-        getenv(DEFER_ENV_VAR) ? "three" : "two",
-        getenv(DEFER_ENV_VAR)
-            ? "    - You are using deferred forkserver, but __AFL_INIT() is "
-              "never\n"
-              "      reached before the program terminates.\n\n"
-            : "",
-        DMS(afl->fsrv.mem_limit << 20), afl->fsrv.mem_limit - 1);
-
-  }
-
-  FATAL("Cmplog fork server handshake failed");
-
-}
-
-u8 run_cmplog_target(afl_state_t *afl, u32 timeout) {
-
-  static struct itimerval it;
-  static u32              prev_timed_out = 0;
-  static u64              exec_ms = 0;
-
-  int status = 0;
-  u32 tb4;
-
-  afl->fsrv.child_timed_out = 0;
-
-  /* After this memset, afl->fsrv.trace_bits[] are effectively volatile, so we
-     must prevent any earlier operations from venturing into that
-     territory. */
-
-  memset(afl->fsrv.trace_bits, 0, MAP_SIZE);
-  MEM_BARRIER();
-
-  /* If we're running in "dumb" mode, we can't rely on the fork server
-     logic compiled into the target program, so we will just keep calling
-     execve(). There is a bit of code duplication between here and
-     init_forkserver(), but c'est la vie. */
-
-  if (afl->dumb_mode == 1 || afl->no_forkserver) {
-
-    afl->cmplog_child_pid = fork();
-
-    if (afl->cmplog_child_pid < 0) PFATAL("fork() failed");
-
-    if (!afl->cmplog_child_pid) {
-
-      struct rlimit r;
-
-      if (afl->fsrv.mem_limit) {
-
-        r.rlim_max = r.rlim_cur = ((rlim_t)afl->fsrv.mem_limit) << 20;
-
-#ifdef RLIMIT_AS
-
-        setrlimit(RLIMIT_AS, &r);                          /* Ignore errors */
-
-#else
-
-        setrlimit(RLIMIT_DATA, &r);                        /* Ignore errors */
-
-#endif                                                        /* ^RLIMIT_AS */
-
-      }
-
-      r.rlim_max = r.rlim_cur = 0;
-
-      setrlimit(RLIMIT_CORE, &r);                          /* Ignore errors */
-
-      /* Isolate the process and configure standard descriptors. If
-         afl->fsrv.out_file is specified, stdin is /dev/null; otherwise,
-         afl->fsrv.out_fd is cloned instead. */
-
-      setsid();
-
-      dup2(afl->fsrv.dev_null_fd, 1);
-      dup2(afl->fsrv.dev_null_fd, 2);
-
-      if (afl->fsrv.out_file) {
-
-        dup2(afl->fsrv.dev_null_fd, 0);
-
-      } else {
-
-        dup2(afl->fsrv.out_fd, 0);
-        close(afl->fsrv.out_fd);
-
-      }
-
-      /* On Linux, would be faster to use O_CLOEXEC. Maybe TODO. */
-
-      close(afl->fsrv.dev_null_fd);
-      close(afl->fsrv.out_dir_fd);
-#ifndef HAVE_ARC4RANDOM
-      close(afl->fsrv.dev_urandom_fd);
-#endif
-      close(fileno(afl->fsrv.plot_file));
-
-      /* Set sane defaults for ASAN if nothing else specified. */
-
-      setenv("ASAN_OPTIONS",
-             "abort_on_error=1:"
-             "detect_leaks=0:"
-             "symbolize=0:"
-             "allocator_may_return_null=1",
-             0);
-
-      setenv("MSAN_OPTIONS", "exit_code=" STRINGIFY(MSAN_ERROR) ":"
-                             "symbolize=0:"
-                             "msan_track_origins=0", 0);
-
-      setenv("___AFL_EINS_ZWEI_POLIZEI___", "1", 1);
-
-      if (!afl->qemu_mode && afl->argv[0] != afl->cmplog_binary) {
-
-        ck_free(afl->argv[0]);
-        afl->argv[0] = afl->cmplog_binary;
-
-      }
-
-      execv(afl->argv[0], afl->argv);
-
-      /* Use a distinctive bitmap value to tell the parent about execv()
-         falling through. */
-
-      *(u32 *)afl->fsrv.trace_bits = EXEC_FAIL_SIG;
-      exit(0);
-
-    }
-
-  } else {
-
-    s32 res;
-
-    /* In non-dumb mode, we have the fork server up and running, so simply
-       tell it to have at it, and then read back PID. */
-
-    if ((res = write(afl->cmplog_fsrv_ctl_fd, &prev_timed_out, 4)) != 4) {
-
-      if (afl->stop_soon) return 0;
-      RPFATAL(res,
-              "Unable to request new process from cmplog fork server (OOM?)");
-
-    }
-
-    if ((res = read(afl->cmplog_fsrv_st_fd, &afl->cmplog_child_pid, 4)) != 4) {
-
-      if (afl->stop_soon) return 0;
-      RPFATAL(res,
-              "Unable to request new process from cmplog fork server (OOM?)");
-
-    }
-
-    if (afl->cmplog_child_pid <= 0)
-      FATAL("Cmplog fork server is misbehaving (OOM?)");
-
-  }
-
-  /* Configure timeout, as requested by user, then wait for child to terminate.
-   */
-
-  it.it_value.tv_sec = (timeout / 1000);
-  it.it_value.tv_usec = (timeout % 1000) * 1000;
-
-  setitimer(ITIMER_REAL, &it, NULL);
-
-  /* The SIGALRM handler simply kills the afl->cmplog_child_pid and sets
-   * afl->fsrv.child_timed_out. */
-
-  if (afl->dumb_mode == 1 || afl->no_forkserver) {
-
-    if (waitpid(afl->cmplog_child_pid, &status, 0) <= 0)
-      PFATAL("waitpid() failed");
-
-  } else {
-
-    s32 res;
-
-    if ((res = read(afl->cmplog_fsrv_st_fd, &status, 4)) != 4) {
-
-      if (afl->stop_soon) return 0;
-      SAYF(
-          "\n" cLRD "[-] " cRST
-          "Unable to communicate with fork server. Some possible reasons:\n\n"
-          "    - You've run out of memory. Use -m to increase the the memory "
-          "limit\n"
-          "      to something higher than %lld.\n"
-          "    - The binary or one of the libraries it uses manages to create\n"
-          "      threads before the forkserver initializes.\n"
-          "    - The binary, at least in some circumstances, exits in a way "
-          "that\n"
-          "      also kills the parent process - raise() could be the "
-          "culprit.\n\n"
-          "If all else fails you can disable the fork server via "
-          "AFL_NO_FORKSRV=1.\n",
-          afl->fsrv.mem_limit);
-      RPFATAL(res, "Unable to communicate with fork server");
-
-    }
-
-  }
-
-  if (!WIFSTOPPED(status)) afl->cmplog_child_pid = 0;
-
-  getitimer(ITIMER_REAL, &it);
-  exec_ms =
-      (u64)timeout - (it.it_value.tv_sec * 1000 + it.it_value.tv_usec / 1000);
-  if (afl->slowest_exec_ms < exec_ms) afl->slowest_exec_ms = exec_ms;
-
-  it.it_value.tv_sec = 0;
-  it.it_value.tv_usec = 0;
-
-  setitimer(ITIMER_REAL, &it, NULL);
-
-  ++afl->total_execs;
-
-  /* Any subsequent operations on afl->fsrv.trace_bits must not be moved by the
-     compiler below this point. Past this location, afl->fsrv.trace_bits[]
-     behave very normally and do not have to be treated as volatile. */
-
-  MEM_BARRIER();
-
-  tb4 = *(u32 *)afl->fsrv.trace_bits;
-
-#ifdef WORD_SIZE_64
-  classify_counts((u64 *)afl->fsrv.trace_bits);
-#else
-  classify_counts((u32 *)afl->fsrv.trace_bits);
-#endif                                                     /* ^WORD_SIZE_64 */
-
-  prev_timed_out = afl->fsrv.child_timed_out;
-
-  /* Report outcome to caller. */
-
-  if (WIFSIGNALED(status) && !afl->stop_soon) {
-
-    afl->kill_signal = WTERMSIG(status);
-
-    if (afl->fsrv.child_timed_out && afl->kill_signal == SIGKILL)
-      return FAULT_TMOUT;
-
-    return FAULT_CRASH;
-
-  }
-
-  /* A somewhat nasty hack for MSAN, which doesn't support abort_on_error and
-     must use a special exit code. */
-
-  if (afl->fsrv.uses_asan && WEXITSTATUS(status) == MSAN_ERROR) {
-
-    afl->kill_signal = 0;
-    return FAULT_CRASH;
-
-  }
-
-  if ((afl->dumb_mode == 1 || afl->no_forkserver) && tb4 == EXEC_FAIL_SIG)
-    return FAULT_ERROR;
-
-  return FAULT_NONE;
+  execv(argv[0], argv);
 
 }
 
@@ -622,14 +50,19 @@ u8 common_fuzz_cmplog_stuff(afl_state_t *afl, u8 *out_buf, u32 len) {
 
   if (afl->post_handler) {
 
-    out_buf = afl->post_handler(out_buf, &len);
-    if (!out_buf || !len) return 0;
+    u8 *post_buf = NULL;
+
+    size_t post_len =
+        afl->post_handler(afl->post_data, out_buf, len, &post_buf);
+    if (!post_buf || !post_len) return 0;
+    out_buf = post_buf;
+    len = post_len;
 
   }
 
   write_to_testcase(afl, out_buf, len);
 
-  fault = run_cmplog_target(afl, afl->fsrv.exec_tmout);
+  fault = run_target(afl, &afl->cmplog_fsrv, afl->fsrv.exec_tmout);
 
   if (afl->stop_soon) return 1;
 
diff --git a/src/afl-fuzz-extras.c b/src/afl-fuzz-extras.c
index ff4c0ae2..55146dd9 100644
--- a/src/afl-fuzz-extras.c
+++ b/src/afl-fuzz-extras.c
@@ -55,6 +55,8 @@ void load_extras_file(afl_state_t *afl, u8 *fname, u32 *min_len, u32 *max_len,
   u8 *  lptr;
   u32   cur_line = 0;
 
+  u8 val_bufs[2][STRINGIFY_VAL_SIZE_MAX];
+
   f = fopen(fname, "r");
 
   if (!f) PFATAL("Unable to open '%s'", fname);
@@ -170,8 +172,10 @@ void load_extras_file(afl_state_t *afl, u8 *fname, u32 *min_len, u32 *max_len,
     afl->extras[afl->extras_cnt].len = klen;
 
     if (afl->extras[afl->extras_cnt].len > MAX_DICT_FILE)
-      FATAL("Keyword too big in line %u (%s, limit is %s)", cur_line, DMS(klen),
-            DMS(MAX_DICT_FILE));
+      FATAL(
+          "Keyword too big in line %u (%s, limit is %s)", cur_line,
+          stringify_mem_size(val_bufs[0], sizeof(val_bufs[0]), klen),
+          stringify_mem_size(val_bufs[1], sizeof(val_bufs[1]), MAX_DICT_FILE));
 
     if (*min_len > klen) *min_len = klen;
     if (*max_len < klen) *max_len = klen;
@@ -193,6 +197,8 @@ void load_extras(afl_state_t *afl, u8 *dir) {
   u32            min_len = MAX_DICT_FILE, max_len = 0, dict_level = 0;
   u8 *           x;
 
+  u8 val_bufs[2][STRINGIFY_VAL_SIZE_MAX];
+
   /* If the name ends with @, extract level and continue. */
 
   if ((x = strchr(dir, '@'))) {
@@ -238,8 +244,10 @@ void load_extras(afl_state_t *afl, u8 *dir) {
     }
 
     if (st.st_size > MAX_DICT_FILE)
-      FATAL("Extra '%s' is too big (%s, limit is %s)", fn, DMS(st.st_size),
-            DMS(MAX_DICT_FILE));
+      FATAL(
+          "Extra '%s' is too big (%s, limit is %s)", fn,
+          stringify_mem_size(val_bufs[0], sizeof(val_bufs[0]), st.st_size),
+          stringify_mem_size(val_bufs[1], sizeof(val_bufs[1]), MAX_DICT_FILE));
 
     if (min_len > st.st_size) min_len = st.st_size;
     if (max_len < st.st_size) max_len = st.st_size;
@@ -273,11 +281,12 @@ check_and_sort:
         compare_extras_len);
 
   OKF("Loaded %u extra tokens, size range %s to %s.", afl->extras_cnt,
-      DMS(min_len), DMS(max_len));
+      stringify_mem_size(val_bufs[0], sizeof(val_bufs[0]), min_len),
+      stringify_mem_size(val_bufs[1], sizeof(val_bufs[1]), max_len));
 
   if (max_len > 32)
     WARNF("Some tokens are relatively large (%s) - consider trimming.",
-          DMS(max_len));
+          stringify_mem_size(val_bufs[0], sizeof(val_bufs[0]), max_len));
 
   if (afl->extras_cnt > MAX_DET_EXTRAS)
     WARNF("More than %d tokens - will use them probabilistically.",
@@ -296,10 +305,14 @@ static inline u8 memcmp_nocase(u8 *m1, u8 *m2, u32 len) {
 }
 
 /* Maybe add automatic extra. */
+/* Ugly hack: afl state is transfered as u8* because we import data via
+   afl-forkserver.c - which is shared with other afl tools that do not
+   have the afl state struct */
 
-void maybe_add_auto(afl_state_t *afl, u8 *mem, u32 len) {
+void maybe_add_auto(void *afl_tmp, u8 *mem, u32 len) {
 
-  u32 i;
+  afl_state_t *afl = (afl_state_t *)afl_tmp;
+  u32          i;
 
   /* Allow users to specify that they don't want auto dictionaries. */
 
@@ -378,7 +391,7 @@ void maybe_add_auto(afl_state_t *afl, u8 *mem, u32 len) {
 
   } else {
 
-    i = MAX_AUTO_EXTRAS / 2 + UR(afl, (MAX_AUTO_EXTRAS + 1) / 2);
+    i = MAX_AUTO_EXTRAS / 2 + rand_below(afl, (MAX_AUTO_EXTRAS + 1) / 2);
 
     ck_free(afl->a_extras[i].data);
 
@@ -442,7 +455,7 @@ void load_auto(afl_state_t *afl) {
     u8 *fn = alloc_printf("%s/.state/auto_extras/auto_%06u", afl->in_dir, i);
     s32 fd, len;
 
-    fd = open(fn, O_RDONLY, 0600);
+    fd = open(fn, O_RDONLY);
 
     if (fd < 0) {
 
@@ -460,7 +473,7 @@ void load_auto(afl_state_t *afl) {
     if (len < 0) PFATAL("Unable to read from '%s'", fn);
 
     if (len >= MIN_AUTO_EXTRA && len <= MAX_AUTO_EXTRA)
-      maybe_add_auto(afl, tmp, len);
+      maybe_add_auto((u8 *)afl, tmp, len);
 
     close(fd);
     ck_free(fn);
diff --git a/src/afl-fuzz-init.c b/src/afl-fuzz-init.c
index 6b5fa24f..54cc81ef 100644
--- a/src/afl-fuzz-init.c
+++ b/src/afl-fuzz-init.c
@@ -24,6 +24,7 @@
  */
 
 #include "afl-fuzz.h"
+#include <limits.h>
 
 #ifdef HAVE_AFFINITY
 
@@ -76,21 +77,16 @@ void bind_to_free_cpu(afl_state_t *afl) {
 
   while ((de = readdir(d))) {
 
-    u8 *  fn;
+    u8    fn[PATH_MAX];
     FILE *f;
     u8    tmp[MAX_LINE];
     u8    has_vmsize = 0;
 
     if (!isdigit(de->d_name[0])) continue;
 
-    fn = alloc_printf("/proc/%s/status", de->d_name);
+    snprintf(fn, PATH_MAX, "/proc/%s/status", de->d_name);
 
-    if (!(f = fopen(fn, "r"))) {
-
-      ck_free(fn);
-      continue;
-
-    }
+    if (!(f = fopen(fn, "r"))) { continue; }
 
     while (fgets(tmp, MAX_LINE, f)) {
 
@@ -111,7 +107,6 @@ void bind_to_free_cpu(afl_state_t *afl) {
 
     }
 
-    ck_free(fn);
     fclose(f);
 
   }
@@ -139,8 +134,15 @@ void bind_to_free_cpu(afl_state_t *afl) {
   for (i = 0; i < proccount; i++) {
 
 #if defined(__FreeBSD__)
-    if (procs[i].ki_oncpu < sizeof(cpu_used) && procs[i].ki_pctcpu > 60)
-      cpu_used[procs[i].ki_oncpu] = 1;
+    if (!strcmp(procs[i].ki_comm, "idle")) continue;
+
+    // fix when ki_oncpu = -1
+    int oncpu;
+    oncpu = procs[i].ki_oncpu;
+    if (oncpu == -1) oncpu = procs[i].ki_lastcpu;
+
+    if (oncpu != -1 && oncpu < sizeof(cpu_used) && procs[i].ki_pctcpu > 60)
+      cpu_used[oncpu] = 1;
 #elif defined(__DragonFly__)
     if (procs[i].kp_lwp.kl_cpuid < sizeof(cpu_used) &&
         procs[i].kp_lwp.kl_pctcpu > 10)
@@ -276,7 +278,9 @@ void setup_post(afl_state_t *afl) {
 
   void *dh;
   u8 *  fn = afl->afl_env.afl_post_library;
+  u8    tbuf[6];
   u32   tlen = 6;
+  strncpy(tbuf, "hello", tlen);
 
   if (!fn) return;
 
@@ -287,10 +291,20 @@ void setup_post(afl_state_t *afl) {
 
   afl->post_handler = dlsym(dh, "afl_postprocess");
   if (!afl->post_handler) FATAL("Symbol 'afl_postprocess' not found.");
+  afl->post_init = dlsym(dh, "afl_postprocess_init");
+  if (!afl->post_init) FATAL("Symbol 'afl_postprocess_init' not found.");
+  afl->post_deinit = dlsym(dh, "afl_postprocess_deinit");
+  if (!afl->post_deinit) FATAL("Symbol 'afl_postprocess_deinit' not found.");
 
   /* Do a quick test. It's better to segfault now than later =) */
 
-  afl->post_handler("hello", &tlen);
+  u8 *post_buf = NULL;
+  afl->post_data = afl->post_init(afl);
+  if (!afl->post_data) FATAL("Could not initialize post handler.");
+
+  size_t post_len = afl->post_handler(afl->post_data, tbuf, tlen, &post_buf);
+  if (!post_len || !post_buf)
+    SAYF("Empty return in test post handler for buf=\"hello\\0\".");
 
   OKF("Postprocessor installed successfully.");
 
@@ -304,7 +318,7 @@ static void shuffle_ptrs(afl_state_t *afl, void **ptrs, u32 cnt) {
 
   for (i = 0; i < cnt - 2; ++i) {
 
-    u32   j = i + UR(afl, cnt - i);
+    u32   j = i + rand_below(afl, cnt - i);
     void *s = ptrs[i];
     ptrs[i] = ptrs[j];
     ptrs[j] = s;
@@ -323,6 +337,8 @@ void read_testcases(afl_state_t *afl) {
   u32             i;
   u8 *            fn1;
 
+  u8 val_buf[2][STRINGIFY_VAL_SIZE_MAX];
+
   /* Auto-detect non-in-place resumption attempts. */
 
   fn1 = alloc_printf("%s/queue", afl->in_dir);
@@ -367,9 +383,10 @@ void read_testcases(afl_state_t *afl) {
 
     struct stat st;
 
+    u8 dfn[PATH_MAX];
+    snprintf(dfn, PATH_MAX, "%s/.state/deterministic_done/%s", afl->in_dir,
+             nl[i]->d_name);
     u8 *fn2 = alloc_printf("%s/%s", afl->in_dir, nl[i]->d_name);
-    u8 *dfn = alloc_printf("%s/.state/deterministic_done/%s", afl->in_dir,
-                           nl[i]->d_name);
 
     u8 passed_det = 0;
 
@@ -383,14 +400,14 @@ void read_testcases(afl_state_t *afl) {
     if (!S_ISREG(st.st_mode) || !st.st_size || strstr(fn2, "/README.txt")) {
 
       ck_free(fn2);
-      ck_free(dfn);
       continue;
 
     }
 
     if (st.st_size > MAX_FILE)
-      FATAL("Test case '%s' is too big (%s, limit is %s)", fn2, DMS(st.st_size),
-            DMS(MAX_FILE));
+      FATAL("Test case '%s' is too big (%s, limit is %s)", fn2,
+            stringify_mem_size(val_buf[0], sizeof(val_buf[0]), st.st_size),
+            stringify_mem_size(val_buf[1], sizeof(val_buf[1]), MAX_FILE));
 
     /* Check for metadata that indicates that deterministic fuzzing
        is complete for this entry. We don't want to repeat deterministic
@@ -398,7 +415,6 @@ void read_testcases(afl_state_t *afl) {
        and probably very time-consuming. */
 
     if (!access(dfn, F_OK)) passed_det = 1;
-    ck_free(dfn);
 
     add_to_queue(afl, fn2, st.st_size, passed_det);
 
@@ -432,11 +448,13 @@ static void check_map_coverage(afl_state_t *afl) {
 
   u32 i;
 
-  if (count_bytes(afl->fsrv.trace_bits) < 100) return;
+  if (count_bytes(afl, afl->fsrv.trace_bits) < 100) return;
 
   for (i = (1 << (MAP_SIZE_POW2 - 1)); i < MAP_SIZE; ++i)
     if (afl->fsrv.trace_bits[i]) return;
 
+  if (afl->fsrv.map_size != MAP_SIZE) return;
+
   WARNF("Recompile binary with newer version of afl to improve coverage!");
 
 }
@@ -553,6 +571,8 @@ void perform_dry_run(afl_state_t *afl) {
 
         if (afl->fsrv.mem_limit) {
 
+          u8 val_buf[STRINGIFY_VAL_SIZE_MAX];
+
           SAYF("\n" cLRD "[-] " cRST
                "Oops, the program crashed with one of the test cases provided. "
                "There are\n"
@@ -593,8 +613,9 @@ void perform_dry_run(afl_state_t *afl) {
                "other options\n"
                "      fail, poke <afl-users@googlegroups.com> for "
                "troubleshooting tips.\n",
-               DMS(afl->fsrv.mem_limit << 20), afl->fsrv.mem_limit - 1,
-               doc_path);
+               stringify_mem_size(val_buf, sizeof(val_buf),
+                                  afl->fsrv.mem_limit << 20),
+               afl->fsrv.mem_limit - 1, doc_path);
 
         } else {
 
@@ -797,7 +818,7 @@ void pivot_inputs(afl_state_t *afl) {
 
 u32 find_start_position(afl_state_t *afl) {
 
-  static u8 tmp[4096];                   /* Ought to be enough for anybody. */
+  u8 tmp[4096] = {0};                    /* Ought to be enough for anybody. */
 
   u8 *fn, *off;
   s32 fd, i;
@@ -834,7 +855,7 @@ u32 find_start_position(afl_state_t *afl) {
 
 void find_timeout(afl_state_t *afl) {
 
-  static u8 tmp[4096];                   /* Ought to be enough for anybody. */
+  u8 tmp[4096] = {0};                    /* Ought to be enough for anybody. */
 
   u8 *fn, *off;
   s32 fd, i;
@@ -902,7 +923,7 @@ static u8 delete_files(u8 *path, u8 *prefix) {
 
 double get_runnable_processes(void) {
 
-  static double res;
+  double res = 0;
 
 #if defined(__APPLE__) || defined(__FreeBSD__) || defined(__OpenBSD__) || \
     defined(__NetBSD__) || defined(__DragonFly__)
@@ -1049,7 +1070,7 @@ static void handle_existing_out_dir(afl_state_t *afl) {
 
     /* Let's see how much work is at stake. */
 
-    if (!afl->in_place_resume &&
+    if (!afl->in_place_resume && last_update > start_time2 &&
         last_update - start_time2 > OUTPUT_GRACE * 60) {
 
       SAYF("\n" cLRD "[-] " cRST
@@ -1787,7 +1808,7 @@ void fix_up_sync(afl_state_t *afl) {
 
 static void handle_resize(int sig) {
 
-  LIST_FOREACH(&afl_states, afl_state_t, { el->clear_screen; });
+  LIST_FOREACH(&afl_states, afl_state_t, { el->clear_screen = 1; });
 
 }
 
@@ -1832,8 +1853,6 @@ static void handle_stop_sig(int sig) {
 
     if (el->fsrv.child_pid > 0) kill(el->fsrv.child_pid, SIGKILL);
     if (el->fsrv.fsrv_pid > 0) kill(el->fsrv.fsrv_pid, SIGKILL);
-    if (el->cmplog_child_pid > 0) kill(el->cmplog_child_pid, SIGKILL);
-    if (el->cmplog_fsrv_pid > 0) kill(el->cmplog_fsrv_pid, SIGKILL);
 
   });
 
@@ -1967,7 +1986,7 @@ void check_binary(afl_state_t *afl, u8 *fname) {
 
 #endif                                                       /* ^!__APPLE__ */
 
-  if (!afl->qemu_mode && !afl->unicorn_mode && !afl->dumb_mode &&
+  if (!afl->fsrv.qemu_mode && !afl->unicorn_mode && !afl->dumb_mode &&
       !memmem(f_data, f_len, SHM_ENV_VAR, strlen(SHM_ENV_VAR) + 1)) {
 
     SAYF("\n" cLRD "[-] " cRST
@@ -1994,7 +2013,7 @@ void check_binary(afl_state_t *afl, u8 *fname) {
 
   }
 
-  if ((afl->qemu_mode) &&
+  if ((afl->fsrv.qemu_mode) &&
       memmem(f_data, f_len, SHM_ENV_VAR, strlen(SHM_ENV_VAR) + 1)) {
 
     SAYF("\n" cLRD "[-] " cRST
@@ -2008,7 +2027,7 @@ void check_binary(afl_state_t *afl, u8 *fname) {
 
   }
 
-  if (memmem(f_data, f_len, "libasan.so", 10) ||
+  if (memmem(f_data, f_len, "__asan_init", 11) ||
       memmem(f_data, f_len, "__msan_init", 11))
     afl->fsrv.uses_asan = 1;
 
@@ -2125,11 +2144,6 @@ void setup_signal_handlers(void) {
   sigaction(SIGINT, &sa, NULL);
   sigaction(SIGTERM, &sa, NULL);
 
-  /* Exec timeout notifications. */
-
-  sa.sa_handler = handle_timeout;
-  sigaction(SIGALRM, &sa, NULL);
-
   /* Window resize */
 
   sa.sa_handler = handle_resize;
diff --git a/src/afl-fuzz-misc.c b/src/afl-fuzz-misc.c
deleted file mode 100644
index 29e8bd82..00000000
--- a/src/afl-fuzz-misc.c
+++ /dev/null
@@ -1,186 +0,0 @@
-/*
-   american fuzzy lop++ - misc stuffs from Mordor
-   ----------------------------------------------
-
-   Originally written by Michal Zalewski
-
-   Now maintained by Marc Heuse <mh@mh-sec.de>,
-                        Heiko Eißfeldt <heiko.eissfeldt@hexco.de> and
-                        Andrea Fioraldi <andreafioraldi@gmail.com>
-
-   Copyright 2016, 2017 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
-
-   This is the real deal: the program takes an instrumented binary and
-   attempts a variety of basic fuzzing tricks, paying close attention to
-   how they affect the execution path.
-
- */
-
-#include "afl-fuzz.h"
-
-/* Describe integer. Uses 12 cyclic static buffers for return values. The value
-   returned should be five characters or less for all the integers we reasonably
-   expect to see. */
-
-u8 *DI(u64 val) {
-
-  static u8 tmp[12][16];
-  static u8 cur;
-
-  cur = (cur + 1) % 12;
-
-#define CHK_FORMAT(_divisor, _limit_mult, _fmt, _cast)    \
-  do {                                                    \
-                                                          \
-    if (val < (_divisor) * (_limit_mult)) {               \
-                                                          \
-      sprintf(tmp[cur], _fmt, ((_cast)val) / (_divisor)); \
-      return tmp[cur];                                    \
-                                                          \
-    }                                                     \
-                                                          \
-  } while (0)
-
-  /* 0-9999 */
-  CHK_FORMAT(1, 10000, "%llu", u64);
-
-  /* 10.0k - 99.9k */
-  CHK_FORMAT(1000, 99.95, "%0.01fk", double);
-
-  /* 100k - 999k */
-  CHK_FORMAT(1000, 1000, "%lluk", u64);
-
-  /* 1.00M - 9.99M */
-  CHK_FORMAT(1000 * 1000, 9.995, "%0.02fM", double);
-
-  /* 10.0M - 99.9M */
-  CHK_FORMAT(1000 * 1000, 99.95, "%0.01fM", double);
-
-  /* 100M - 999M */
-  CHK_FORMAT(1000 * 1000, 1000, "%lluM", u64);
-
-  /* 1.00G - 9.99G */
-  CHK_FORMAT(1000LL * 1000 * 1000, 9.995, "%0.02fG", double);
-
-  /* 10.0G - 99.9G */
-  CHK_FORMAT(1000LL * 1000 * 1000, 99.95, "%0.01fG", double);
-
-  /* 100G - 999G */
-  CHK_FORMAT(1000LL * 1000 * 1000, 1000, "%lluG", u64);
-
-  /* 1.00T - 9.99G */
-  CHK_FORMAT(1000LL * 1000 * 1000 * 1000, 9.995, "%0.02fT", double);
-
-  /* 10.0T - 99.9T */
-  CHK_FORMAT(1000LL * 1000 * 1000 * 1000, 99.95, "%0.01fT", double);
-
-  /* 100T+ */
-  strcpy(tmp[cur], "infty");
-  return tmp[cur];
-
-}
-
-/* Describe float. Similar to the above, except with a single
-   static buffer. */
-
-u8 *DF(double val) {
-
-  static u8 tmp[16];
-
-  if (val < 99.995) {
-
-    sprintf(tmp, "%0.02f", val);
-    return tmp;
-
-  }
-
-  if (val < 999.95) {
-
-    sprintf(tmp, "%0.01f", val);
-    return tmp;
-
-  }
-
-  return DI((u64)val);
-
-}
-
-/* Describe integer as memory size. */
-
-u8 *DMS(u64 val) {
-
-  static u8 tmp[12][16];
-  static u8 cur;
-
-  cur = (cur + 1) % 12;
-
-  /* 0-9999 */
-  CHK_FORMAT(1, 10000, "%llu B", u64);
-
-  /* 10.0k - 99.9k */
-  CHK_FORMAT(1024, 99.95, "%0.01f kB", double);
-
-  /* 100k - 999k */
-  CHK_FORMAT(1024, 1000, "%llu kB", u64);
-
-  /* 1.00M - 9.99M */
-  CHK_FORMAT(1024 * 1024, 9.995, "%0.02f MB", double);
-
-  /* 10.0M - 99.9M */
-  CHK_FORMAT(1024 * 1024, 99.95, "%0.01f MB", double);
-
-  /* 100M - 999M */
-  CHK_FORMAT(1024 * 1024, 1000, "%llu MB", u64);
-
-  /* 1.00G - 9.99G */
-  CHK_FORMAT(1024LL * 1024 * 1024, 9.995, "%0.02f GB", double);
-
-  /* 10.0G - 99.9G */
-  CHK_FORMAT(1024LL * 1024 * 1024, 99.95, "%0.01f GB", double);
-
-  /* 100G - 999G */
-  CHK_FORMAT(1024LL * 1024 * 1024, 1000, "%llu GB", u64);
-
-  /* 1.00T - 9.99G */
-  CHK_FORMAT(1024LL * 1024 * 1024 * 1024, 9.995, "%0.02f TB", double);
-
-  /* 10.0T - 99.9T */
-  CHK_FORMAT(1024LL * 1024 * 1024 * 1024, 99.95, "%0.01f TB", double);
-
-#undef CHK_FORMAT
-
-  /* 100T+ */
-  strcpy(tmp[cur], "infty");
-  return tmp[cur];
-
-}
-
-/* Describe time delta. Returns one static buffer, 34 chars of less. */
-
-u8 *DTD(u64 cur_ms, u64 event_ms) {
-
-  static u8 tmp[64];
-  u64       delta;
-  s32       t_d, t_h, t_m, t_s;
-
-  if (!event_ms) return "none seen yet";
-
-  delta = cur_ms - event_ms;
-
-  t_d = delta / 1000 / 60 / 60 / 24;
-  t_h = (delta / 1000 / 60 / 60) % 24;
-  t_m = (delta / 1000 / 60) % 60;
-  t_s = (delta / 1000) % 60;
-
-  sprintf(tmp, "%s days, %d hrs, %d min, %d sec", DI(t_d), t_h, t_m, t_s);
-  return tmp;
-
-}
-
diff --git a/src/afl-fuzz-mutators.c b/src/afl-fuzz-mutators.c
index 9071404d..efb1c117 100644
--- a/src/afl-fuzz-mutators.c
+++ b/src/afl-fuzz-mutators.c
@@ -7,6 +7,7 @@
    Now maintained by  Marc Heuse <mh@mh-sec.de>,
                         Heiko Eißfeldt <heiko.eissfeldt@hexco.de> and
                         Andrea Fioraldi <andreafioraldi@gmail.com>
+                        Dominik Maier <mail@dmnk.co>
 
    Copyright 2016, 2017 Google Inc. All rights reserved.
    Copyright 2019-2020 AFLplusplus Project. All rights reserved.
@@ -27,13 +28,13 @@
 
 void load_custom_mutator(afl_state_t *, const char *);
 #ifdef USE_PYTHON
-void load_custom_mutator_py(afl_state_t *, const char *);
+void load_custom_mutator_py(afl_state_t *, char *);
 #endif
 
 void setup_custom_mutator(afl_state_t *afl) {
 
   /* Try mutator library first */
-  u8 *fn = getenv("AFL_CUSTOM_MUTATOR_LIBRARY");
+  u8 *fn = afl->afl_env.afl_custom_mutator_library;
 
   if (fn) {
 
@@ -51,7 +52,7 @@ void setup_custom_mutator(afl_state_t *afl) {
 
   /* Try Python module */
 #ifdef USE_PYTHON
-  u8 *module_name = getenv("AFL_PYTHON_MODULE");
+  u8 *module_name = afl->afl_env.afl_python_module;
 
   if (module_name) {
 
@@ -59,17 +60,14 @@ void setup_custom_mutator(afl_state_t *afl) {
       FATAL(
           "MOpt and Python mutator are mutually exclusive. We accept pull "
           "requests that integrates MOpt with the optional mutators "
-          "(custom/radamsa/redquenn/...).");
-
-    if (init_py_module(afl, module_name))
-      FATAL("Failed to initialize Python module");
+          "(custom/radamsa/redqueen/...).");
 
     load_custom_mutator_py(afl, module_name);
 
   }
 
 #else
-  if (getenv("AFL_PYTHON_MODULE"))
+  if (afl->afl_env.afl_python_module)
     FATAL("Your AFL binary was built without Python support");
 #endif
 
@@ -79,18 +77,20 @@ void destroy_custom_mutator(afl_state_t *afl) {
 
   if (afl->mutator) {
 
-    if (afl->mutator->dh)
-      dlclose(afl->mutator->dh);
-    else {
+    afl->mutator->afl_custom_deinit(afl->mutator->data);
 
-      /* Python mutator */
-#ifdef USE_PYTHON
-      finalize_py_module(afl);
-#endif
+    if (afl->mutator->dh) dlclose(afl->mutator->dh);
+
+    if (afl->mutator->pre_save_buf) {
+
+      ck_free(afl->mutator->pre_save_buf);
+      afl->mutator->pre_save_buf = NULL;
+      afl->mutator->pre_save_size = 0;
 
     }
 
     ck_free(afl->mutator);
+    afl->mutator = NULL;
 
   }
 
@@ -100,6 +100,8 @@ void load_custom_mutator(afl_state_t *afl, const char *fn) {
 
   void *dh;
   afl->mutator = ck_alloc(sizeof(struct custom_mutator));
+  afl->mutator->pre_save_buf = NULL;
+  afl->mutator->pre_save_size = 0;
 
   afl->mutator->name = fn;
   ACTF("Loading custom mutator library from '%s'...", fn);
@@ -109,10 +111,15 @@ void load_custom_mutator(afl_state_t *afl, const char *fn) {
   afl->mutator->dh = dh;
 
   /* Mutator */
-  /* "afl_custom_init", optional for backward compatibility */
+  /* "afl_custom_init", required */
   afl->mutator->afl_custom_init = dlsym(dh, "afl_custom_init");
   if (!afl->mutator->afl_custom_init)
-    WARNF("Symbol 'afl_custom_init' not found.");
+    FATAL("Symbol 'afl_custom_init' not found.");
+
+  /* "afl_custom_deinit", required */
+  afl->mutator->afl_custom_deinit = dlsym(dh, "afl_custom_deinit");
+  if (!afl->mutator->afl_custom_deinit)
+    FATAL("Symbol 'afl_custom_deinit' not found.");
 
   /* "afl_custom_fuzz" or "afl_custom_mutator", required */
   afl->mutator->afl_custom_fuzz = dlsym(dh, "afl_custom_fuzz");
@@ -186,59 +193,58 @@ void load_custom_mutator(afl_state_t *afl, const char *fn) {
 
   /* Initialize the custom mutator */
   if (afl->mutator->afl_custom_init)
-    afl->mutator->afl_custom_init(afl, UR(afl, 0xFFFFFFFF));
+    afl->mutator->data =
+        afl->mutator->afl_custom_init(afl, rand_below(afl, 0xFFFFFFFF));
 
 }
 
 u8 trim_case_custom(afl_state_t *afl, struct queue_entry *q, u8 *in_buf) {
 
-  static u8 tmp[64];
-  static u8 clean_trace[MAP_SIZE];
-
   u8  needs_write = 0, fault = 0;
   u32 trim_exec = 0;
   u32 orig_len = q->len;
 
-  afl->stage_name = tmp;
+  u8 val_buf[STRINGIFY_VAL_SIZE_MAX];
+
+  afl->stage_name = afl->stage_name_buf;
   afl->bytes_trim_in += q->len;
 
   /* Initialize trimming in the custom mutator */
   afl->stage_cur = 0;
-  afl->stage_max = afl->mutator->afl_custom_init_trim(afl, in_buf, q->len);
-
+  afl->stage_max =
+      afl->mutator->afl_custom_init_trim(afl->mutator->data, in_buf, q->len);
+  if (unlikely(afl->stage_max) < 0)
+    FATAL("custom_init_trim error ret: %d", afl->stage_max);
   if (afl->not_on_tty && afl->debug)
     SAYF("[Custom Trimming] START: Max %d iterations, %u bytes", afl->stage_max,
          q->len);
 
   while (afl->stage_cur < afl->stage_max) {
 
-    sprintf(tmp, "ptrim %s", DI(trim_exec));
+    u8 *retbuf = NULL;
 
-    u32 cksum;
+    sprintf(afl->stage_name_buf, "ptrim %s",
+            u_stringify_int(val_buf, trim_exec));
 
-    u8 *   retbuf = NULL;
-    size_t retlen = 0;
+    u32 cksum;
 
-    afl->mutator->afl_custom_trim(afl, &retbuf, &retlen);
+    size_t retlen = afl->mutator->afl_custom_trim(afl->mutator->data, &retbuf);
 
-    if (retlen > orig_len)
+    if (unlikely(!retbuf))
+      FATAL("custom_trim failed (ret %zd)", retlen);
+    else if (unlikely(retlen > orig_len))
       FATAL(
           "Trimmed data returned by custom mutator is larger than original "
           "data");
 
     write_to_testcase(afl, retbuf, retlen);
 
-    fault = run_target(afl, afl->fsrv.exec_tmout);
+    fault = run_target(afl, &afl->fsrv, afl->fsrv.exec_tmout);
     ++afl->trim_execs;
 
-    if (afl->stop_soon || fault == FAULT_ERROR) {
-
-      ck_free(retbuf);
-      goto abort_trimming;
-
-    }
+    if (afl->stop_soon || fault == FAULT_ERROR) { goto abort_trimming; }
 
-    cksum = hash32(afl->fsrv.trace_bits, MAP_SIZE, HASH_CONST);
+    cksum = hash32(afl->fsrv.trace_bits, afl->fsrv.map_size, HASH_CONST);
 
     if (cksum == q->exec_cksum) {
 
@@ -251,12 +257,14 @@ u8 trim_case_custom(afl_state_t *afl, struct queue_entry *q, u8 *in_buf) {
       if (!needs_write) {
 
         needs_write = 1;
-        memcpy(clean_trace, afl->fsrv.trace_bits, MAP_SIZE);
+        memcpy(afl->clean_trace_custom, afl->fsrv.trace_bits,
+               afl->fsrv.map_size);
 
       }
 
       /* Tell the custom mutator that the trimming was successful */
-      afl->stage_cur = afl->mutator->afl_custom_post_trim(afl, 1);
+      afl->stage_cur =
+          afl->mutator->afl_custom_post_trim(afl->mutator->data, 1);
 
       if (afl->not_on_tty && afl->debug)
         SAYF("[Custom Trimming] SUCCESS: %d/%d iterations (now at %u bytes)",
@@ -265,15 +273,16 @@ u8 trim_case_custom(afl_state_t *afl, struct queue_entry *q, u8 *in_buf) {
     } else {
 
       /* Tell the custom mutator that the trimming was unsuccessful */
-      afl->stage_cur = afl->mutator->afl_custom_post_trim(afl, 0);
+      afl->stage_cur =
+          afl->mutator->afl_custom_post_trim(afl->mutator->data, 0);
+      if (unlikely(afl->stage_cur < 0))
+        FATAL("Error ret in custom_post_trim: %d", afl->stage_cur);
       if (afl->not_on_tty && afl->debug)
         SAYF("[Custom Trimming] FAILURE: %d/%d iterations", afl->stage_cur,
              afl->stage_max);
 
     }
 
-    ck_free(retbuf);
-
     /* Since this can be slow, update the screen every now and then. */
 
     if (!(trim_exec++ % afl->stats_update_freq)) show_stats(afl);
@@ -299,7 +308,7 @@ u8 trim_case_custom(afl_state_t *afl, struct queue_entry *q, u8 *in_buf) {
     ck_write(fd, in_buf, q->len, q->fname);
     close(fd);
 
-    memcpy(afl->fsrv.trace_bits, clean_trace, MAP_SIZE);
+    memcpy(afl->fsrv.trace_bits, afl->clean_trace_custom, afl->fsrv.map_size);
     update_bitmap_score(afl, q);
 
   }
@@ -311,53 +320,3 @@ abort_trimming:
 
 }
 
-#ifdef USE_PYTHON
-void load_custom_mutator_py(afl_state_t *afl, const char *module_name) {
-
-  PyObject **py_functions = afl->py_functions;
-
-  afl->mutator = ck_alloc(sizeof(struct custom_mutator));
-
-  afl->mutator->name = module_name;
-  ACTF("Loading Python mutator library from '%s'...", module_name);
-
-  if (py_functions[PY_FUNC_INIT]) afl->mutator->afl_custom_init = init_py;
-
-  /* "afl_custom_fuzz" should not be NULL, but the interface of Python mutator
-     is quite different from the custom mutator. */
-  afl->mutator->afl_custom_fuzz = fuzz_py;
-
-  if (py_functions[PY_FUNC_PRE_SAVE])
-    afl->mutator->afl_custom_pre_save = pre_save_py;
-
-  if (py_functions[PY_FUNC_INIT_TRIM])
-    afl->mutator->afl_custom_init_trim = init_trim_py;
-
-  if (py_functions[PY_FUNC_POST_TRIM])
-    afl->mutator->afl_custom_post_trim = post_trim_py;
-
-  if (py_functions[PY_FUNC_TRIM]) afl->mutator->afl_custom_trim = trim_py;
-
-  if (py_functions[PY_FUNC_HAVOC_MUTATION])
-    afl->mutator->afl_custom_havoc_mutation = havoc_mutation_py;
-
-  if (py_functions[PY_FUNC_HAVOC_MUTATION_PROBABILITY])
-    afl->mutator->afl_custom_havoc_mutation_probability =
-        havoc_mutation_probability_py;
-
-  if (py_functions[PY_FUNC_QUEUE_GET])
-    afl->mutator->afl_custom_queue_get = queue_get_py;
-
-  if (py_functions[PY_FUNC_QUEUE_NEW_ENTRY])
-    afl->mutator->afl_custom_queue_new_entry = queue_new_entry_py;
-
-  OKF("Python mutator '%s' installed successfully.", module_name);
-
-  /* Initialize the custom mutator */
-  if (afl->mutator->afl_custom_init)
-    afl->mutator->afl_custom_init(afl, UR(afl, 0xFFFFFFFF));
-
-}
-
-#endif
-
diff --git a/src/afl-fuzz-one.c b/src/afl-fuzz-one.c
index c4d49ec1..4a039a1d 100644
--- a/src/afl-fuzz-one.c
+++ b/src/afl-fuzz-one.c
@@ -31,7 +31,7 @@ int select_algorithm(afl_state_t *afl) {
 
   int i_puppet, j_puppet;
 
-  double sele = ((double)(UR(afl, 10000)) * 0.0001);
+  double sele = ((double)(rand_below(afl, 10000)) * 0.0001);
   j_puppet = 0;
   for (i_puppet = 0; i_puppet < operator_num; ++i_puppet) {
 
@@ -67,9 +67,9 @@ static u32 choose_block_len(afl_state_t *afl, u32 limit) {
   u32 min_value, max_value;
   u32 rlim = MIN(afl->queue_cycle, 3);
 
-  if (!afl->run_over10m) rlim = 1;
+  if (unlikely(!afl->run_over10m)) rlim = 1;
 
-  switch (UR(afl, rlim)) {
+  switch (rand_below(afl, rlim)) {
 
     case 0:
       min_value = 1;
@@ -83,7 +83,7 @@ static u32 choose_block_len(afl_state_t *afl, u32 limit) {
 
     default:
 
-      if (UR(afl, 10)) {
+      if (rand_below(afl, 10)) {
 
         min_value = HAVOC_BLK_MEDIUM;
         max_value = HAVOC_BLK_LARGE;
@@ -99,7 +99,7 @@ static u32 choose_block_len(afl_state_t *afl, u32 limit) {
 
   if (min_value >= limit) min_value = 1;
 
-  return min_value + UR(afl, MIN(max_value, limit) - min_value + 1);
+  return min_value + rand_below(afl, MIN(max_value, limit) - min_value + 1);
 
 }
 
@@ -347,6 +347,9 @@ u8 fuzz_one_original(afl_state_t *afl) {
   u8  a_collect[MAX_AUTO_EXTRA];
   u32 a_len = 0;
 
+/* Not pretty, but saves a lot of writing */
+#define BUF_PARAMS(name) (void **)&afl->name##_buf, &afl->name##_size
+
 #ifdef IGNORE_FINDS
 
   /* In IGNORE_FINDS mode, skip any entries that weren't in the
@@ -356,16 +359,17 @@ u8 fuzz_one_original(afl_state_t *afl) {
 
 #else
 
-  if (afl->mutator && afl->mutator->afl_custom_queue_get) {
+  if (unlikely(afl->mutator) && unlikely(afl->mutator->afl_custom_queue_get)) {
 
     /* The custom mutator will decide to skip this test case or not. */
 
-    if (!afl->mutator->afl_custom_queue_get(afl, afl->queue_cur->fname))
+    if (!afl->mutator->afl_custom_queue_get(afl->mutator->data,
+                                            afl->queue_cur->fname))
       return 1;
 
   }
 
-  if (afl->pending_favored) {
+  if (likely(afl->pending_favored)) {
 
     /* If we have any favored, non-fuzzed new arrivals in the queue,
        possibly skip to them at the expense of already-fuzzed or non-favored
@@ -373,7 +377,7 @@ u8 fuzz_one_original(afl_state_t *afl) {
 
     if (((afl->queue_cur->was_fuzzed > 0 || afl->queue_cur->fuzz_level > 0) ||
          !afl->queue_cur->favored) &&
-        UR(afl, 100) < SKIP_TO_NEW_PROB)
+        rand_below(afl, 100) < SKIP_TO_NEW_PROB)
       return 1;
 
   } else if (!afl->dumb_mode && !afl->queue_cur->favored &&
@@ -387,11 +391,11 @@ u8 fuzz_one_original(afl_state_t *afl) {
     if (afl->queue_cycle > 1 &&
         (afl->queue_cur->fuzz_level == 0 || afl->queue_cur->was_fuzzed)) {
 
-      if (UR(afl, 100) < SKIP_NFAV_NEW_PROB) return 1;
+      if (rand_below(afl, 100) < SKIP_NFAV_NEW_PROB) return 1;
 
     } else {
 
-      if (UR(afl, 100) < SKIP_NFAV_OLD_PROB) return 1;
+      if (rand_below(afl, 100) < SKIP_NFAV_OLD_PROB) return 1;
 
     }
 
@@ -399,7 +403,7 @@ u8 fuzz_one_original(afl_state_t *afl) {
 
 #endif                                                     /* ^IGNORE_FINDS */
 
-  if (afl->not_on_tty) {
+  if (unlikely(afl->not_on_tty)) {
 
     ACTF("Fuzzing test case #%u (%u total, %llu uniq crashes found)...",
          afl->current_entry, afl->queued_paths, afl->unique_crashes);
@@ -411,13 +415,13 @@ u8 fuzz_one_original(afl_state_t *afl) {
 
   fd = open(afl->queue_cur->fname, O_RDONLY);
 
-  if (fd < 0) PFATAL("Unable to open '%s'", afl->queue_cur->fname);
+  if (unlikely(fd < 0)) PFATAL("Unable to open '%s'", afl->queue_cur->fname);
 
   len = afl->queue_cur->len;
 
   orig_in = in_buf = mmap(0, len, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
 
-  if (orig_in == MAP_FAILED)
+  if (unlikely(orig_in == MAP_FAILED))
     PFATAL("Unable to mmap '%s' with len %d", afl->queue_cur->fname, len);
 
   close(fd);
@@ -426,7 +430,7 @@ u8 fuzz_one_original(afl_state_t *afl) {
      single byte anyway, so it wouldn't give us any performance or memory usage
      benefits. */
 
-  out_buf = ck_alloc_nozero(len);
+  out_buf = ck_maybe_grow(BUF_PARAMS(out), len);
 
   afl->subseq_tmouts = 0;
 
@@ -436,7 +440,7 @@ u8 fuzz_one_original(afl_state_t *afl) {
    * CALIBRATION (only if failed earlier on) *
    *******************************************/
 
-  if (afl->queue_cur->cal_failed) {
+  if (unlikely(afl->queue_cur->cal_failed)) {
 
     u8 res = FAULT_TMOUT;
 
@@ -445,11 +449,12 @@ u8 fuzz_one_original(afl_state_t *afl) {
       res =
           calibrate_case(afl, afl->queue_cur, in_buf, afl->queue_cycle - 1, 0);
 
-      if (res == FAULT_ERROR) FATAL("Unable to execute target application");
+      if (unlikely(res == FAULT_ERROR))
+        FATAL("Unable to execute target application");
 
     }
 
-    if (afl->stop_soon || res != afl->crash_mode) {
+    if (unlikely(afl->stop_soon) || res != afl->crash_mode) {
 
       ++afl->cur_skipped_paths;
       goto abandon_entry;
@@ -466,9 +471,10 @@ u8 fuzz_one_original(afl_state_t *afl) {
 
     u8 res = trim_case(afl, afl->queue_cur, in_buf);
 
-    if (res == FAULT_ERROR) FATAL("Unable to execute target application");
+    if (unlikely(res == FAULT_ERROR))
+      FATAL("Unable to execute target application");
 
-    if (afl->stop_soon) {
+    if (unlikely(afl->stop_soon)) {
 
       ++afl->cur_skipped_paths;
       goto abandon_entry;
@@ -491,9 +497,9 @@ u8 fuzz_one_original(afl_state_t *afl) {
 
   orig_perf = perf_score = calculate_score(afl, afl->queue_cur);
 
-  if (perf_score == 0) goto abandon_entry;
+  if (unlikely(perf_score == 0)) goto abandon_entry;
 
-  if (afl->use_radamsa > 1) goto radamsa_stage;
+  if (unlikely(afl->use_radamsa > 1)) goto radamsa_stage;
 
   if (afl->shm.cmplog_mode && !afl->queue_cur->fully_colorized) {
 
@@ -595,7 +601,7 @@ u8 fuzz_one_original(afl_state_t *afl) {
 
     if (!afl->dumb_mode && (afl->stage_cur & 7) == 7) {
 
-      u32 cksum = hash32(afl->fsrv.trace_bits, MAP_SIZE, HASH_CONST);
+      u32 cksum = hash32(afl->fsrv.trace_bits, afl->fsrv.map_size, HASH_CONST);
 
       if (afl->stage_cur == afl->stage_max - 1 && cksum == prev_cksum) {
 
@@ -607,7 +613,7 @@ u8 fuzz_one_original(afl_state_t *afl) {
         ++a_len;
 
         if (a_len >= MIN_AUTO_EXTRA && a_len <= MAX_AUTO_EXTRA)
-          maybe_add_auto(afl, a_collect, a_len);
+          maybe_add_auto((u8 *)afl, a_collect, a_len);
 
       } else if (cksum != prev_cksum) {
 
@@ -615,7 +621,7 @@ u8 fuzz_one_original(afl_state_t *afl) {
            worthwhile queued up, and collect that if the answer is yes. */
 
         if (a_len >= MIN_AUTO_EXTRA && a_len <= MAX_AUTO_EXTRA)
-          maybe_add_auto(afl, a_collect, a_len);
+          maybe_add_auto((u8 *)afl, a_collect, a_len);
 
         a_len = 0;
         prev_cksum = cksum;
@@ -716,7 +722,7 @@ u8 fuzz_one_original(afl_state_t *afl) {
   /* Initialize effector map for the next step (see comments below). Always
      flag first and last byte as doing something. */
 
-  eff_map = ck_alloc(EFF_ALEN(len));
+  eff_map = ck_maybe_grow(BUF_PARAMS(eff), EFF_ALEN(len));
   eff_map[0] = 1;
 
   if (EFF_APOS(len - 1) != 0) {
@@ -755,7 +761,7 @@ u8 fuzz_one_original(afl_state_t *afl) {
          without wasting time on checksums. */
 
       if (!afl->dumb_mode && len >= EFF_MIN_LEN)
-        cksum = hash32(afl->fsrv.trace_bits, MAP_SIZE, HASH_CONST);
+        cksum = hash32(afl->fsrv.trace_bits, afl->fsrv.map_size, HASH_CONST);
       else
         cksum = ~afl->queue_cur->exec_cksum;
 
@@ -1401,7 +1407,7 @@ skip_interest:
          map. */
 
       if ((afl->extras_cnt > MAX_DET_EXTRAS &&
-           UR(afl, afl->extras_cnt) >= MAX_DET_EXTRAS) ||
+           rand_below(afl, afl->extras_cnt) >= MAX_DET_EXTRAS) ||
           afl->extras[j].len > len - i ||
           !memcmp(afl->extras[j].data, out_buf + i, afl->extras[j].len) ||
           !memchr(eff_map + EFF_APOS(i), 1,
@@ -1440,7 +1446,7 @@ skip_interest:
 
   orig_hit_cnt = new_hit_cnt;
 
-  ex_tmp = ck_alloc(len + MAX_DICT_FILE);
+  ex_tmp = ck_maybe_grow(BUF_PARAMS(ex), len + MAX_DICT_FILE);
 
   for (i = 0; i <= len; ++i) {
 
@@ -1463,7 +1469,6 @@ skip_interest:
 
       if (common_fuzz_stuff(afl, ex_tmp, len + afl->extras[j].len)) {
 
-        ck_free(ex_tmp);
         goto abandon_entry;
 
       }
@@ -1477,8 +1482,6 @@ skip_interest:
 
   }
 
-  ck_free(ex_tmp);
-
   new_hit_cnt = afl->queued_paths + afl->unique_crashes;
 
   afl->stage_finds[STAGE_EXTRAS_UI] += new_hit_cnt - orig_hit_cnt;
@@ -1549,8 +1552,8 @@ custom_mutator_stage:
    * CUSTOM MUTATORS *
    *******************/
 
-  if (!afl->mutator) goto havoc_stage;
-  if (!afl->mutator->afl_custom_fuzz) goto havoc_stage;
+  if (likely(!afl->mutator)) goto havoc_stage;
+  if (likely(!afl->mutator->afl_custom_fuzz)) goto havoc_stage;
 
   afl->stage_name = "custom mutator";
   afl->stage_short = "custom";
@@ -1573,7 +1576,7 @@ custom_mutator_stage:
     /* Pick a random other queue entry for passing to external API */
     do {
 
-      tid = UR(afl, afl->queued_paths);
+      tid = rand_below(afl, afl->queued_paths);
 
     } while (tid == afl->current_entry && afl->queued_paths > 1);
 
@@ -1603,19 +1606,24 @@ custom_mutator_stage:
 
     /* Read the additional testcase into a new buffer. */
     fd = open(target->fname, O_RDONLY);
-    if (fd < 0) PFATAL("Unable to open '%s'", target->fname);
-    new_buf = ck_alloc_nozero(target->len);
+    if (unlikely(fd < 0)) PFATAL("Unable to open '%s'", target->fname);
+
+    new_buf = ck_maybe_grow(BUF_PARAMS(out_scratch), target->len);
     ck_read(fd, new_buf, target->len, target->fname);
     close(fd);
 
+    u8 *mutated_buf = NULL;
+
     size_t mutated_size = afl->mutator->afl_custom_fuzz(
-        afl, &out_buf, len, new_buf, target->len, max_seed_size);
+        afl->mutator->data, out_buf, len, &mutated_buf, new_buf, target->len,
+        max_seed_size);
 
-    ck_free(new_buf);
+    if (unlikely(!mutated_buf))
+      FATAL("Error in custom_fuzz. Size returned: %zd", mutated_size);
 
     if (mutated_size > 0) {
 
-      if (common_fuzz_stuff(afl, out_buf, (u32)mutated_size)) {
+      if (common_fuzz_stuff(afl, mutated_buf, (u32)mutated_size)) {
 
         goto abandon_entry;
 
@@ -1639,7 +1647,8 @@ custom_mutator_stage:
 
     }
 
-    if (mutated_size < len) out_buf = ck_realloc(out_buf, len);
+    /* `(afl->)out_buf` may have been changed by the call to custom_fuzz */
+    /* TODO: Only do this when `mutated_buf` == `out_buf`? Branch vs Memcpy. */
     memcpy(out_buf, in_buf, len);
 
   }
@@ -1649,7 +1658,7 @@ custom_mutator_stage:
   afl->stage_finds[STAGE_CUSTOM_MUTATOR] += new_hit_cnt - orig_hit_cnt;
   afl->stage_cycles[STAGE_CUSTOM_MUTATOR] += afl->stage_max;
 
-  if (afl->custom_only) {
+  if (likely(afl->custom_only)) {
 
     /* Skip other stages */
     ret_val = 0;
@@ -1679,8 +1688,8 @@ havoc_stage:
 
     perf_score = orig_perf;
 
-    snprintf(afl->stage_name_buf64, 64, "splice %u", splice_cycle);
-    afl->stage_name = afl->stage_name_buf64;
+    snprintf(afl->stage_name_buf, STAGE_BUF_SIZE, "splice %u", splice_cycle);
+    afl->stage_name = afl->stage_name_buf;
     afl->stage_short = "splice";
     afl->stage_max = SPLICE_HAVOC * perf_score / afl->havoc_div / 100;
 
@@ -1700,7 +1709,7 @@ havoc_stage:
   if (stacked_custom && afl->mutator->afl_custom_havoc_mutation_probability) {
 
     stacked_custom_prob =
-        afl->mutator->afl_custom_havoc_mutation_probability(afl);
+        afl->mutator->afl_custom_havoc_mutation_probability(afl->mutator->data);
     if (stacked_custom_prob > 100)
       FATAL(
           "The probability returned by afl_custom_havoc_mutation_propability "
@@ -1713,34 +1722,49 @@ havoc_stage:
 
   for (afl->stage_cur = 0; afl->stage_cur < afl->stage_max; ++afl->stage_cur) {
 
-    u32 use_stacking = 1 << (1 + UR(afl, HAVOC_STACK_POW2));
+    u32 use_stacking = 1 << (1 + rand_below(afl, HAVOC_STACK_POW2));
 
     afl->stage_cur_val = use_stacking;
 
     for (i = 0; i < use_stacking; ++i) {
 
-      if (stacked_custom && UR(afl, 100) < stacked_custom_prob) {
+      if (stacked_custom && rand_below(afl, 100) < stacked_custom_prob) {
+
+        u8 *   custom_havoc_buf = NULL;
+        size_t new_len = afl->mutator->afl_custom_havoc_mutation(
+            afl->mutator->data, out_buf, temp_len, &custom_havoc_buf, MAX_FILE);
+        if (unlikely(!custom_havoc_buf))
+          FATAL("Error in custom_havoc (return %zd)", new_len);
+        if (likely(new_len > 0 && custom_havoc_buf)) {
 
-        temp_len = afl->mutator->afl_custom_havoc_mutation(afl, &out_buf,
-                                                           temp_len, MAX_FILE);
+          temp_len = new_len;
+          if (out_buf != custom_havoc_buf) {
+
+            ck_maybe_grow(BUF_PARAMS(out), temp_len);
+            memcpy(out_buf, custom_havoc_buf, temp_len);
+
+          }
+
+        }
 
       }
 
-      switch (UR(afl, 15 + ((afl->extras_cnt + afl->a_extras_cnt) ? 2 : 0))) {
+      switch (rand_below(
+          afl, 15 + ((afl->extras_cnt + afl->a_extras_cnt) ? 2 : 0))) {
 
         case 0:
 
           /* Flip a single bit somewhere. Spooky! */
 
-          FLIP_BIT(out_buf, UR(afl, temp_len << 3));
+          FLIP_BIT(out_buf, rand_below(afl, temp_len << 3));
           break;
 
         case 1:
 
           /* Set byte to interesting value. */
 
-          out_buf[UR(afl, temp_len)] =
-              interesting_8[UR(afl, sizeof(interesting_8))];
+          out_buf[rand_below(afl, temp_len)] =
+              interesting_8[rand_below(afl, sizeof(interesting_8))];
           break;
 
         case 2:
@@ -1749,15 +1773,15 @@ havoc_stage:
 
           if (temp_len < 2) break;
 
-          if (UR(afl, 2)) {
+          if (rand_below(afl, 2)) {
 
-            *(u16 *)(out_buf + UR(afl, temp_len - 1)) =
-                interesting_16[UR(afl, sizeof(interesting_16) >> 1)];
+            *(u16 *)(out_buf + rand_below(afl, temp_len - 1)) =
+                interesting_16[rand_below(afl, sizeof(interesting_16) >> 1)];
 
           } else {
 
-            *(u16 *)(out_buf + UR(afl, temp_len - 1)) =
-                SWAP16(interesting_16[UR(afl, sizeof(interesting_16) >> 1)]);
+            *(u16 *)(out_buf + rand_below(afl, temp_len - 1)) = SWAP16(
+                interesting_16[rand_below(afl, sizeof(interesting_16) >> 1)]);
 
           }
 
@@ -1769,15 +1793,15 @@ havoc_stage:
 
           if (temp_len < 4) break;
 
-          if (UR(afl, 2)) {
+          if (rand_below(afl, 2)) {
 
-            *(u32 *)(out_buf + UR(afl, temp_len - 3)) =
-                interesting_32[UR(afl, sizeof(interesting_32) >> 2)];
+            *(u32 *)(out_buf + rand_below(afl, temp_len - 3)) =
+                interesting_32[rand_below(afl, sizeof(interesting_32) >> 2)];
 
           } else {
 
-            *(u32 *)(out_buf + UR(afl, temp_len - 3)) =
-                SWAP32(interesting_32[UR(afl, sizeof(interesting_32) >> 2)]);
+            *(u32 *)(out_buf + rand_below(afl, temp_len - 3)) = SWAP32(
+                interesting_32[rand_below(afl, sizeof(interesting_32) >> 2)]);
 
           }
 
@@ -1787,14 +1811,14 @@ havoc_stage:
 
           /* Randomly subtract from byte. */
 
-          out_buf[UR(afl, temp_len)] -= 1 + UR(afl, ARITH_MAX);
+          out_buf[rand_below(afl, temp_len)] -= 1 + rand_below(afl, ARITH_MAX);
           break;
 
         case 5:
 
           /* Randomly add to byte. */
 
-          out_buf[UR(afl, temp_len)] += 1 + UR(afl, ARITH_MAX);
+          out_buf[rand_below(afl, temp_len)] += 1 + rand_below(afl, ARITH_MAX);
           break;
 
         case 6:
@@ -1803,16 +1827,16 @@ havoc_stage:
 
           if (temp_len < 2) break;
 
-          if (UR(afl, 2)) {
+          if (rand_below(afl, 2)) {
 
-            u32 pos = UR(afl, temp_len - 1);
+            u32 pos = rand_below(afl, temp_len - 1);
 
-            *(u16 *)(out_buf + pos) -= 1 + UR(afl, ARITH_MAX);
+            *(u16 *)(out_buf + pos) -= 1 + rand_below(afl, ARITH_MAX);
 
           } else {
 
-            u32 pos = UR(afl, temp_len - 1);
-            u16 num = 1 + UR(afl, ARITH_MAX);
+            u32 pos = rand_below(afl, temp_len - 1);
+            u16 num = 1 + rand_below(afl, ARITH_MAX);
 
             *(u16 *)(out_buf + pos) =
                 SWAP16(SWAP16(*(u16 *)(out_buf + pos)) - num);
@@ -1827,16 +1851,16 @@ havoc_stage:
 
           if (temp_len < 2) break;
 
-          if (UR(afl, 2)) {
+          if (rand_below(afl, 2)) {
 
-            u32 pos = UR(afl, temp_len - 1);
+            u32 pos = rand_below(afl, temp_len - 1);
 
-            *(u16 *)(out_buf + pos) += 1 + UR(afl, ARITH_MAX);
+            *(u16 *)(out_buf + pos) += 1 + rand_below(afl, ARITH_MAX);
 
           } else {
 
-            u32 pos = UR(afl, temp_len - 1);
-            u16 num = 1 + UR(afl, ARITH_MAX);
+            u32 pos = rand_below(afl, temp_len - 1);
+            u16 num = 1 + rand_below(afl, ARITH_MAX);
 
             *(u16 *)(out_buf + pos) =
                 SWAP16(SWAP16(*(u16 *)(out_buf + pos)) + num);
@@ -1851,16 +1875,16 @@ havoc_stage:
 
           if (temp_len < 4) break;
 
-          if (UR(afl, 2)) {
+          if (rand_below(afl, 2)) {
 
-            u32 pos = UR(afl, temp_len - 3);
+            u32 pos = rand_below(afl, temp_len - 3);
 
-            *(u32 *)(out_buf + pos) -= 1 + UR(afl, ARITH_MAX);
+            *(u32 *)(out_buf + pos) -= 1 + rand_below(afl, ARITH_MAX);
 
           } else {
 
-            u32 pos = UR(afl, temp_len - 3);
-            u32 num = 1 + UR(afl, ARITH_MAX);
+            u32 pos = rand_below(afl, temp_len - 3);
+            u32 num = 1 + rand_below(afl, ARITH_MAX);
 
             *(u32 *)(out_buf + pos) =
                 SWAP32(SWAP32(*(u32 *)(out_buf + pos)) - num);
@@ -1875,16 +1899,16 @@ havoc_stage:
 
           if (temp_len < 4) break;
 
-          if (UR(afl, 2)) {
+          if (rand_below(afl, 2)) {
 
-            u32 pos = UR(afl, temp_len - 3);
+            u32 pos = rand_below(afl, temp_len - 3);
 
-            *(u32 *)(out_buf + pos) += 1 + UR(afl, ARITH_MAX);
+            *(u32 *)(out_buf + pos) += 1 + rand_below(afl, ARITH_MAX);
 
           } else {
 
-            u32 pos = UR(afl, temp_len - 3);
-            u32 num = 1 + UR(afl, ARITH_MAX);
+            u32 pos = rand_below(afl, temp_len - 3);
+            u32 num = 1 + rand_below(afl, ARITH_MAX);
 
             *(u32 *)(out_buf + pos) =
                 SWAP32(SWAP32(*(u32 *)(out_buf + pos)) + num);
@@ -1899,7 +1923,7 @@ havoc_stage:
              why not. We use XOR with 1-255 to eliminate the
              possibility of a no-op. */
 
-          out_buf[UR(afl, temp_len)] ^= 1 + UR(afl, 255);
+          out_buf[rand_below(afl, temp_len)] ^= 1 + rand_below(afl, 255);
           break;
 
         case 11 ... 12: {
@@ -1916,7 +1940,7 @@ havoc_stage:
 
           del_len = choose_block_len(afl, temp_len - 1);
 
-          del_from = UR(afl, temp_len - del_len + 1);
+          del_from = rand_below(afl, temp_len - del_len + 1);
 
           memmove(out_buf + del_from, out_buf + del_from + del_len,
                   temp_len - del_from - del_len);
@@ -1933,14 +1957,14 @@ havoc_stage:
 
             /* Clone bytes (75%) or insert a block of constant bytes (25%). */
 
-            u8  actually_clone = UR(afl, 4);
+            u8  actually_clone = rand_below(afl, 4);
             u32 clone_from, clone_to, clone_len;
             u8 *new_buf;
 
             if (actually_clone) {
 
               clone_len = choose_block_len(afl, temp_len);
-              clone_from = UR(afl, temp_len - clone_len + 1);
+              clone_from = rand_below(afl, temp_len - clone_len + 1);
 
             } else {
 
@@ -1949,9 +1973,10 @@ havoc_stage:
 
             }
 
-            clone_to = UR(afl, temp_len);
+            clone_to = rand_below(afl, temp_len);
 
-            new_buf = ck_alloc_nozero(temp_len + clone_len);
+            new_buf =
+                ck_maybe_grow(BUF_PARAMS(out_scratch), temp_len + clone_len);
 
             /* Head */
 
@@ -1963,15 +1988,17 @@ havoc_stage:
               memcpy(new_buf + clone_to, out_buf + clone_from, clone_len);
             else
               memset(new_buf + clone_to,
-                     UR(afl, 2) ? UR(afl, 256) : out_buf[UR(afl, temp_len)],
+                     rand_below(afl, 2) ? rand_below(afl, 256)
+                                        : out_buf[rand_below(afl, temp_len)],
                      clone_len);
 
             /* Tail */
             memcpy(new_buf + clone_to + clone_len, out_buf + clone_to,
                    temp_len - clone_to);
 
-            ck_free(out_buf);
+            swap_bufs(BUF_PARAMS(out), BUF_PARAMS(out_scratch));
             out_buf = new_buf;
+            new_buf = NULL;
             temp_len += clone_len;
 
           }
@@ -1989,10 +2016,10 @@ havoc_stage:
 
           copy_len = choose_block_len(afl, temp_len - 1);
 
-          copy_from = UR(afl, temp_len - copy_len + 1);
-          copy_to = UR(afl, temp_len - copy_len + 1);
+          copy_from = rand_below(afl, temp_len - copy_len + 1);
+          copy_to = rand_below(afl, temp_len - copy_len + 1);
 
-          if (UR(afl, 4)) {
+          if (rand_below(afl, 4)) {
 
             if (copy_from != copy_to)
               memmove(out_buf + copy_to, out_buf + copy_from, copy_len);
@@ -2000,7 +2027,8 @@ havoc_stage:
           } else
 
             memset(out_buf + copy_to,
-                   UR(afl, 2) ? UR(afl, 256) : out_buf[UR(afl, temp_len)],
+                   rand_below(afl, 2) ? rand_below(afl, 256)
+                                      : out_buf[rand_below(afl, temp_len)],
                    copy_len);
 
           break;
@@ -2014,18 +2042,18 @@ havoc_stage:
 
           /* Overwrite bytes with an extra. */
 
-          if (!afl->extras_cnt || (afl->a_extras_cnt && UR(afl, 2))) {
+          if (!afl->extras_cnt || (afl->a_extras_cnt && rand_below(afl, 2))) {
 
             /* No user-specified extras or odds in our favor. Let's use an
                auto-detected one. */
 
-            u32 use_extra = UR(afl, afl->a_extras_cnt);
+            u32 use_extra = rand_below(afl, afl->a_extras_cnt);
             u32 extra_len = afl->a_extras[use_extra].len;
             u32 insert_at;
 
             if (extra_len > temp_len) break;
 
-            insert_at = UR(afl, temp_len - extra_len + 1);
+            insert_at = rand_below(afl, temp_len - extra_len + 1);
             memcpy(out_buf + insert_at, afl->a_extras[use_extra].data,
                    extra_len);
 
@@ -2033,13 +2061,13 @@ havoc_stage:
 
             /* No auto extras or odds in our favor. Use the dictionary. */
 
-            u32 use_extra = UR(afl, afl->extras_cnt);
+            u32 use_extra = rand_below(afl, afl->extras_cnt);
             u32 extra_len = afl->extras[use_extra].len;
             u32 insert_at;
 
             if (extra_len > temp_len) break;
 
-            insert_at = UR(afl, temp_len - extra_len + 1);
+            insert_at = rand_below(afl, temp_len - extra_len + 1);
             memcpy(out_buf + insert_at, afl->extras[use_extra].data, extra_len);
 
           }
@@ -2050,20 +2078,21 @@ havoc_stage:
 
         case 16: {
 
-          u32 use_extra, extra_len, insert_at = UR(afl, temp_len + 1);
+          u32 use_extra, extra_len, insert_at = rand_below(afl, temp_len + 1);
           u8 *new_buf;
 
           /* Insert an extra. Do the same dice-rolling stuff as for the
              previous case. */
 
-          if (!afl->extras_cnt || (afl->a_extras_cnt && UR(afl, 2))) {
+          if (!afl->extras_cnt || (afl->a_extras_cnt && rand_below(afl, 2))) {
 
-            use_extra = UR(afl, afl->a_extras_cnt);
+            use_extra = rand_below(afl, afl->a_extras_cnt);
             extra_len = afl->a_extras[use_extra].len;
 
             if (temp_len + extra_len >= MAX_FILE) break;
 
-            new_buf = ck_alloc_nozero(temp_len + extra_len);
+            new_buf =
+                ck_maybe_grow(BUF_PARAMS(out_scratch), temp_len + extra_len);
 
             /* Head */
             memcpy(new_buf, out_buf, insert_at);
@@ -2074,12 +2103,13 @@ havoc_stage:
 
           } else {
 
-            use_extra = UR(afl, afl->extras_cnt);
+            use_extra = rand_below(afl, afl->extras_cnt);
             extra_len = afl->extras[use_extra].len;
 
             if (temp_len + extra_len >= MAX_FILE) break;
 
-            new_buf = ck_alloc_nozero(temp_len + extra_len);
+            new_buf =
+                ck_maybe_grow(BUF_PARAMS(out_scratch), temp_len + extra_len);
 
             /* Head */
             memcpy(new_buf, out_buf, insert_at);
@@ -2093,8 +2123,9 @@ havoc_stage:
           memcpy(new_buf + insert_at + extra_len, out_buf + insert_at,
                  temp_len - insert_at);
 
-          ck_free(out_buf);
+          swap_bufs(BUF_PARAMS(out), BUF_PARAMS(out_scratch));
           out_buf = new_buf;
+          new_buf = NULL;
           temp_len += extra_len;
 
           break;
@@ -2110,7 +2141,7 @@ havoc_stage:
     /* out_buf might have been mangled a bit, so let's restore it to its
        original size and shape. */
 
-    if (temp_len < len) out_buf = ck_realloc(out_buf, len);
+    out_buf = ck_maybe_grow(BUF_PARAMS(out), len);
     temp_len = len;
     memcpy(out_buf, in_buf, len);
 
@@ -2172,7 +2203,6 @@ retry_splicing:
 
     if (in_buf != orig_in) {
 
-      ck_free(in_buf);
       in_buf = orig_in;
       len = afl->queue_cur->len;
 
@@ -2182,7 +2212,7 @@ retry_splicing:
 
     do {
 
-      tid = UR(afl, afl->queued_paths);
+      tid = rand_below(afl, afl->queued_paths);
 
     } while (tid == afl->current_entry);
 
@@ -2214,9 +2244,9 @@ retry_splicing:
 
     fd = open(target->fname, O_RDONLY);
 
-    if (fd < 0) PFATAL("Unable to open '%s'", target->fname);
+    if (unlikely(fd < 0)) PFATAL("Unable to open '%s'", target->fname);
 
-    new_buf = ck_alloc_nozero(target->len);
+    new_buf = ck_maybe_grow(BUF_PARAMS(in_scratch), target->len);
 
     ck_read(fd, new_buf, target->len, target->fname);
 
@@ -2228,25 +2258,20 @@ retry_splicing:
 
     locate_diffs(in_buf, new_buf, MIN(len, target->len), &f_diff, &l_diff);
 
-    if (f_diff < 0 || l_diff < 2 || f_diff == l_diff) {
-
-      ck_free(new_buf);
-      goto retry_splicing;
-
-    }
+    if (f_diff < 0 || l_diff < 2 || f_diff == l_diff) { goto retry_splicing; }
 
     /* Split somewhere between the first and last differing byte. */
 
-    split_at = f_diff + UR(afl, l_diff - f_diff);
+    split_at = f_diff + rand_below(afl, l_diff - f_diff);
 
     /* Do the thing. */
 
     len = target->len;
     memcpy(new_buf, in_buf, split_at);
+    swap_bufs(BUF_PARAMS(in), BUF_PARAMS(in_scratch));
     in_buf = new_buf;
 
-    ck_free(out_buf);
-    out_buf = ck_alloc_nozero(len);
+    out_buf = ck_maybe_grow(BUF_PARAMS(out), len);
     memcpy(out_buf, in_buf, len);
 
     goto custom_mutator_stage;
@@ -2263,7 +2288,7 @@ retry_splicing:
 
 radamsa_stage:
 
-  if (!afl->use_radamsa || !afl->radamsa_mutate_ptr) goto abandon_entry;
+  if (likely(!afl->use_radamsa || !afl->radamsa_mutate_ptr)) goto abandon_entry;
 
   afl->stage_name = "radamsa";
   afl->stage_short = "radamsa";
@@ -2274,12 +2299,14 @@ radamsa_stage:
 
   orig_hit_cnt = afl->queued_paths + afl->unique_crashes;
 
-  /* Read the additional testcase into a new buffer. */
-  u8 *save_buf = ck_alloc_nozero(len);
+  /* Read the additional testcase.
+  We'll reuse in_scratch, as it is free at this point.
+  */
+  u8 *save_buf = ck_maybe_grow(BUF_PARAMS(in_scratch), len);
   memcpy(save_buf, out_buf, len);
 
   u32 max_len = len + choose_block_len(afl, HAVOC_BLK_XL);
-  u8 *new_buf = ck_alloc_nozero(max_len);
+  u8 *new_buf = ck_maybe_grow(BUF_PARAMS(out_scratch), max_len);
   u8 *tmp_buf;
 
   for (afl->stage_cur = 0; afl->stage_cur < afl->stage_max; ++afl->stage_cur) {
@@ -2299,19 +2326,10 @@ radamsa_stage:
 
     }
 
-    if (common_fuzz_stuff(afl, tmp_buf, temp_len)) {
-
-      ck_free(save_buf);
-      ck_free(new_buf);
-      goto abandon_entry;
-
-    }
+    if (common_fuzz_stuff(afl, tmp_buf, temp_len)) { goto abandon_entry; }
 
   }
 
-  ck_free(save_buf);
-  ck_free(new_buf);
-
   new_hit_cnt = afl->queued_paths + afl->unique_crashes;
 
   afl->stage_finds[STAGE_RADAMSA] += new_hit_cnt - orig_hit_cnt;
@@ -2341,10 +2359,6 @@ abandon_entry:
 
   munmap(orig_in, afl->queue_cur->len);
 
-  if (in_buf != orig_in) ck_free(in_buf);
-  ck_free(out_buf);
-  ck_free(eff_map);
-
   return ret_val;
 
 #undef FLIP_BIT
@@ -2391,7 +2405,7 @@ u8 mopt_common_fuzzing(afl_state_t *afl, MOpt_globals_t MOpt_globals) {
        cases. */
 
     if ((afl->queue_cur->was_fuzzed || !afl->queue_cur->favored) &&
-        UR(afl, 100) < SKIP_TO_NEW_PROB)
+        rand_below(afl, 100) < SKIP_TO_NEW_PROB)
       return 1;
 
   } else if (!afl->dumb_mode && !afl->queue_cur->favored &&
@@ -2404,11 +2418,11 @@ u8 mopt_common_fuzzing(afl_state_t *afl, MOpt_globals_t MOpt_globals) {
 
     if (afl->queue_cycle > 1 && !afl->queue_cur->was_fuzzed) {
 
-      if (UR(afl, 100) < SKIP_NFAV_NEW_PROB) return 1;
+      if (rand_below(afl, 100) < SKIP_NFAV_NEW_PROB) return 1;
 
     } else {
 
-      if (UR(afl, 100) < SKIP_NFAV_OLD_PROB) return 1;
+      if (rand_below(afl, 100) < SKIP_NFAV_OLD_PROB) return 1;
 
     }
 
@@ -2443,7 +2457,7 @@ u8 mopt_common_fuzzing(afl_state_t *afl, MOpt_globals_t MOpt_globals) {
      single byte anyway, so it wouldn't give us any performance or memory usage
      benefits. */
 
-  out_buf = ck_alloc_nozero(len);
+  out_buf = ck_maybe_grow(BUF_PARAMS(out), len);
 
   afl->subseq_tmouts = 0;
 
@@ -2612,7 +2626,7 @@ u8 mopt_common_fuzzing(afl_state_t *afl, MOpt_globals_t MOpt_globals) {
 
     if (!afl->dumb_mode && (afl->stage_cur & 7) == 7) {
 
-      u32 cksum = hash32(afl->fsrv.trace_bits, MAP_SIZE, HASH_CONST);
+      u32 cksum = hash32(afl->fsrv.trace_bits, afl->fsrv.map_size, HASH_CONST);
 
       if (afl->stage_cur == afl->stage_max - 1 && cksum == prev_cksum) {
 
@@ -2624,7 +2638,7 @@ u8 mopt_common_fuzzing(afl_state_t *afl, MOpt_globals_t MOpt_globals) {
         ++a_len;
 
         if (a_len >= MIN_AUTO_EXTRA && a_len <= MAX_AUTO_EXTRA)
-          maybe_add_auto(afl, a_collect, a_len);
+          maybe_add_auto((u8 *)afl, a_collect, a_len);
 
       } else if (cksum != prev_cksum) {
 
@@ -2632,7 +2646,7 @@ u8 mopt_common_fuzzing(afl_state_t *afl, MOpt_globals_t MOpt_globals) {
            worthwhile queued up, and collect that if the answer is yes. */
 
         if (a_len >= MIN_AUTO_EXTRA && a_len <= MAX_AUTO_EXTRA)
-          maybe_add_auto(afl, a_collect, a_len);
+          maybe_add_auto((u8 *)afl, a_collect, a_len);
 
         a_len = 0;
         prev_cksum = cksum;
@@ -2733,7 +2747,7 @@ u8 mopt_common_fuzzing(afl_state_t *afl, MOpt_globals_t MOpt_globals) {
   /* Initialize effector map for the next step (see comments below). Always
          flag first and last byte as doing something. */
 
-  eff_map = ck_alloc(EFF_ALEN(len));
+  eff_map = ck_maybe_grow(BUF_PARAMS(eff), EFF_ALEN(len));
   eff_map[0] = 1;
 
   if (EFF_APOS(len - 1) != 0) {
@@ -2772,7 +2786,7 @@ u8 mopt_common_fuzzing(afl_state_t *afl, MOpt_globals_t MOpt_globals) {
          without wasting time on checksums. */
 
       if (!afl->dumb_mode && len >= EFF_MIN_LEN)
-        cksum = hash32(afl->fsrv.trace_bits, MAP_SIZE, HASH_CONST);
+        cksum = hash32(afl->fsrv.trace_bits, afl->fsrv.map_size, HASH_CONST);
       else
         cksum = ~afl->queue_cur->exec_cksum;
 
@@ -3418,7 +3432,7 @@ skip_interest:
          map. */
 
       if ((afl->extras_cnt > MAX_DET_EXTRAS &&
-           UR(afl, afl->extras_cnt) >= MAX_DET_EXTRAS) ||
+           rand_below(afl, afl->extras_cnt) >= MAX_DET_EXTRAS) ||
           afl->extras[j].len > len - i ||
           !memcmp(afl->extras[j].data, out_buf + i, afl->extras[j].len) ||
           !memchr(eff_map + EFF_APOS(i), 1,
@@ -3457,7 +3471,7 @@ skip_interest:
 
   orig_hit_cnt = new_hit_cnt;
 
-  ex_tmp = ck_alloc(len + MAX_DICT_FILE);
+  ex_tmp = ck_maybe_grow(BUF_PARAMS(ex), len + MAX_DICT_FILE);
 
   for (i = 0; i <= len; ++i) {
 
@@ -3480,7 +3494,6 @@ skip_interest:
 
       if (common_fuzz_stuff(afl, ex_tmp, len + afl->extras[j].len)) {
 
-        ck_free(ex_tmp);
         goto abandon_entry;
 
       }
@@ -3494,8 +3507,6 @@ skip_interest:
 
   }                                                  /* for i = 0; i <= len */
 
-  ck_free(ex_tmp);
-
   new_hit_cnt = afl->queued_paths + afl->unique_crashes;
 
   afl->stage_finds[STAGE_EXTRAS_UI] += new_hit_cnt - orig_hit_cnt;
@@ -3584,9 +3595,9 @@ pacemaker_fuzzing:
 
     perf_score = orig_perf;
 
-    snprintf(afl->stage_name_buf64, 64, MOpt_globals.splice_stageformat,
-             splice_cycle);
-    afl->stage_name = afl->stage_name_buf64;
+    snprintf(afl->stage_name_buf, STAGE_BUF_SIZE,
+             MOpt_globals.splice_stageformat, splice_cycle);
+    afl->stage_name = afl->stage_name_buf;
     afl->stage_short = MOpt_globals.splice_stagenameshort;
     afl->stage_max = SPLICE_HAVOC * perf_score / afl->havoc_div / 100;
 
@@ -3605,7 +3616,8 @@ pacemaker_fuzzing:
         afl->orig_hit_cnt_puppet = afl->queued_paths + afl->unique_crashes;
         afl->last_limit_time_start = get_cur_time();
         afl->SPLICE_CYCLES_puppet =
-            (UR(afl, SPLICE_CYCLES_puppet_up - SPLICE_CYCLES_puppet_low + 1) +
+            (rand_below(
+                 afl, SPLICE_CYCLES_puppet_up - SPLICE_CYCLES_puppet_low + 1) +
              SPLICE_CYCLES_puppet_low);
 
       }
@@ -3634,9 +3646,9 @@ pacemaker_fuzzing:
       } else {
 
         perf_score = orig_perf;
-        snprintf(afl->stage_name_buf64, 64, MOpt_globals.splice_stageformat,
-                 splice_cycle);
-        afl->stage_name = afl->stage_name_buf64;
+        snprintf(afl->stage_name_buf, STAGE_BUF_SIZE,
+                 MOpt_globals.splice_stageformat, splice_cycle);
+        afl->stage_name = afl->stage_name_buf;
         afl->stage_short = MOpt_globals.splice_stagenameshort;
         afl->stage_max = SPLICE_HAVOC * perf_score / afl->havoc_div / 100;
 
@@ -3653,7 +3665,7 @@ pacemaker_fuzzing:
       for (afl->stage_cur = 0; afl->stage_cur < afl->stage_max;
            ++afl->stage_cur) {
 
-        u32 use_stacking = 1 << (1 + UR(afl, HAVOC_STACK_POW2));
+        u32 use_stacking = 1 << (1 + rand_below(afl, HAVOC_STACK_POW2));
 
         afl->stage_cur_val = use_stacking;
 
@@ -3669,13 +3681,13 @@ pacemaker_fuzzing:
 
             case 0:
               /* Flip a single bit somewhere. Spooky! */
-              FLIP_BIT(out_buf, UR(afl, temp_len << 3));
+              FLIP_BIT(out_buf, rand_below(afl, temp_len << 3));
               MOpt_globals.cycles_v2[STAGE_FLIP1] += 1;
               break;
 
             case 1:
               if (temp_len < 2) break;
-              temp_len_puppet = UR(afl, (temp_len << 3) - 1);
+              temp_len_puppet = rand_below(afl, (temp_len << 3) - 1);
               FLIP_BIT(out_buf, temp_len_puppet);
               FLIP_BIT(out_buf, temp_len_puppet + 1);
               MOpt_globals.cycles_v2[STAGE_FLIP2] += 1;
@@ -3683,7 +3695,7 @@ pacemaker_fuzzing:
 
             case 2:
               if (temp_len < 2) break;
-              temp_len_puppet = UR(afl, (temp_len << 3) - 3);
+              temp_len_puppet = rand_below(afl, (temp_len << 3) - 3);
               FLIP_BIT(out_buf, temp_len_puppet);
               FLIP_BIT(out_buf, temp_len_puppet + 1);
               FLIP_BIT(out_buf, temp_len_puppet + 2);
@@ -3693,55 +3705,57 @@ pacemaker_fuzzing:
 
             case 3:
               if (temp_len < 4) break;
-              out_buf[UR(afl, temp_len)] ^= 0xFF;
+              out_buf[rand_below(afl, temp_len)] ^= 0xFF;
               MOpt_globals.cycles_v2[STAGE_FLIP8] += 1;
               break;
 
             case 4:
               if (temp_len < 8) break;
-              *(u16 *)(out_buf + UR(afl, temp_len - 1)) ^= 0xFFFF;
+              *(u16 *)(out_buf + rand_below(afl, temp_len - 1)) ^= 0xFFFF;
               MOpt_globals.cycles_v2[STAGE_FLIP16] += 1;
               break;
 
             case 5:
               if (temp_len < 8) break;
-              *(u32 *)(out_buf + UR(afl, temp_len - 3)) ^= 0xFFFFFFFF;
+              *(u32 *)(out_buf + rand_below(afl, temp_len - 3)) ^= 0xFFFFFFFF;
               MOpt_globals.cycles_v2[STAGE_FLIP32] += 1;
               break;
 
             case 6:
-              out_buf[UR(afl, temp_len)] -= 1 + UR(afl, ARITH_MAX);
-              out_buf[UR(afl, temp_len)] += 1 + UR(afl, ARITH_MAX);
+              out_buf[rand_below(afl, temp_len)] -=
+                  1 + rand_below(afl, ARITH_MAX);
+              out_buf[rand_below(afl, temp_len)] +=
+                  1 + rand_below(afl, ARITH_MAX);
               MOpt_globals.cycles_v2[STAGE_ARITH8] += 1;
               break;
 
             case 7:
               /* Randomly subtract from word, random endian. */
               if (temp_len < 8) break;
-              if (UR(afl, 2)) {
+              if (rand_below(afl, 2)) {
 
-                u32 pos = UR(afl, temp_len - 1);
-                *(u16 *)(out_buf + pos) -= 1 + UR(afl, ARITH_MAX);
+                u32 pos = rand_below(afl, temp_len - 1);
+                *(u16 *)(out_buf + pos) -= 1 + rand_below(afl, ARITH_MAX);
 
               } else {
 
-                u32 pos = UR(afl, temp_len - 1);
-                u16 num = 1 + UR(afl, ARITH_MAX);
+                u32 pos = rand_below(afl, temp_len - 1);
+                u16 num = 1 + rand_below(afl, ARITH_MAX);
                 *(u16 *)(out_buf + pos) =
                     SWAP16(SWAP16(*(u16 *)(out_buf + pos)) - num);
 
               }
 
               /* Randomly add to word, random endian. */
-              if (UR(afl, 2)) {
+              if (rand_below(afl, 2)) {
 
-                u32 pos = UR(afl, temp_len - 1);
-                *(u16 *)(out_buf + pos) += 1 + UR(afl, ARITH_MAX);
+                u32 pos = rand_below(afl, temp_len - 1);
+                *(u16 *)(out_buf + pos) += 1 + rand_below(afl, ARITH_MAX);
 
               } else {
 
-                u32 pos = UR(afl, temp_len - 1);
-                u16 num = 1 + UR(afl, ARITH_MAX);
+                u32 pos = rand_below(afl, temp_len - 1);
+                u16 num = 1 + rand_below(afl, ARITH_MAX);
                 *(u16 *)(out_buf + pos) =
                     SWAP16(SWAP16(*(u16 *)(out_buf + pos)) + num);
 
@@ -3753,15 +3767,15 @@ pacemaker_fuzzing:
             case 8:
               /* Randomly subtract from dword, random endian. */
               if (temp_len < 8) break;
-              if (UR(afl, 2)) {
+              if (rand_below(afl, 2)) {
 
-                u32 pos = UR(afl, temp_len - 3);
-                *(u32 *)(out_buf + pos) -= 1 + UR(afl, ARITH_MAX);
+                u32 pos = rand_below(afl, temp_len - 3);
+                *(u32 *)(out_buf + pos) -= 1 + rand_below(afl, ARITH_MAX);
 
               } else {
 
-                u32 pos = UR(afl, temp_len - 3);
-                u32 num = 1 + UR(afl, ARITH_MAX);
+                u32 pos = rand_below(afl, temp_len - 3);
+                u32 num = 1 + rand_below(afl, ARITH_MAX);
                 *(u32 *)(out_buf + pos) =
                     SWAP32(SWAP32(*(u32 *)(out_buf + pos)) - num);
 
@@ -3769,15 +3783,15 @@ pacemaker_fuzzing:
 
               /* Randomly add to dword, random endian. */
               // if (temp_len < 4) break;
-              if (UR(afl, 2)) {
+              if (rand_below(afl, 2)) {
 
-                u32 pos = UR(afl, temp_len - 3);
-                *(u32 *)(out_buf + pos) += 1 + UR(afl, ARITH_MAX);
+                u32 pos = rand_below(afl, temp_len - 3);
+                *(u32 *)(out_buf + pos) += 1 + rand_below(afl, ARITH_MAX);
 
               } else {
 
-                u32 pos = UR(afl, temp_len - 3);
-                u32 num = 1 + UR(afl, ARITH_MAX);
+                u32 pos = rand_below(afl, temp_len - 3);
+                u32 num = 1 + rand_below(afl, ARITH_MAX);
                 *(u32 *)(out_buf + pos) =
                     SWAP32(SWAP32(*(u32 *)(out_buf + pos)) + num);
 
@@ -3789,23 +3803,25 @@ pacemaker_fuzzing:
             case 9:
               /* Set byte to interesting value. */
               if (temp_len < 4) break;
-              out_buf[UR(afl, temp_len)] =
-                  interesting_8[UR(afl, sizeof(interesting_8))];
+              out_buf[rand_below(afl, temp_len)] =
+                  interesting_8[rand_below(afl, sizeof(interesting_8))];
               MOpt_globals.cycles_v2[STAGE_INTEREST8] += 1;
               break;
 
             case 10:
               /* Set word to interesting value, randomly choosing endian. */
               if (temp_len < 8) break;
-              if (UR(afl, 2)) {
+              if (rand_below(afl, 2)) {
 
-                *(u16 *)(out_buf + UR(afl, temp_len - 1)) =
-                    interesting_16[UR(afl, sizeof(interesting_16) >> 1)];
+                *(u16 *)(out_buf + rand_below(afl, temp_len - 1)) =
+                    interesting_16[rand_below(afl,
+                                              sizeof(interesting_16) >> 1)];
 
               } else {
 
-                *(u16 *)(out_buf + UR(afl, temp_len - 1)) = SWAP16(
-                    interesting_16[UR(afl, sizeof(interesting_16) >> 1)]);
+                *(u16 *)(out_buf + rand_below(afl, temp_len - 1)) =
+                    SWAP16(interesting_16[rand_below(
+                        afl, sizeof(interesting_16) >> 1)]);
 
               }
 
@@ -3817,15 +3833,17 @@ pacemaker_fuzzing:
 
               if (temp_len < 8) break;
 
-              if (UR(afl, 2)) {
+              if (rand_below(afl, 2)) {
 
-                *(u32 *)(out_buf + UR(afl, temp_len - 3)) =
-                    interesting_32[UR(afl, sizeof(interesting_32) >> 2)];
+                *(u32 *)(out_buf + rand_below(afl, temp_len - 3)) =
+                    interesting_32[rand_below(afl,
+                                              sizeof(interesting_32) >> 2)];
 
               } else {
 
-                *(u32 *)(out_buf + UR(afl, temp_len - 3)) = SWAP32(
-                    interesting_32[UR(afl, sizeof(interesting_32) >> 2)]);
+                *(u32 *)(out_buf + rand_below(afl, temp_len - 3)) =
+                    SWAP32(interesting_32[rand_below(
+                        afl, sizeof(interesting_32) >> 2)]);
 
               }
 
@@ -3838,7 +3856,7 @@ pacemaker_fuzzing:
                  why not. We use XOR with 1-255 to eliminate the
                  possibility of a no-op. */
 
-              out_buf[UR(afl, temp_len)] ^= 1 + UR(afl, 255);
+              out_buf[rand_below(afl, temp_len)] ^= 1 + rand_below(afl, 255);
               MOpt_globals.cycles_v2[STAGE_RANDOMBYTE] += 1;
               break;
 
@@ -3856,7 +3874,7 @@ pacemaker_fuzzing:
 
               del_len = choose_block_len(afl, temp_len - 1);
 
-              del_from = UR(afl, temp_len - del_len + 1);
+              del_from = rand_below(afl, temp_len - del_len + 1);
 
               memmove(out_buf + del_from, out_buf + del_from + del_len,
                       temp_len - del_from - del_len);
@@ -3874,14 +3892,14 @@ pacemaker_fuzzing:
                 /* Clone bytes (75%) or insert a block of constant bytes (25%).
                  */
 
-                u8  actually_clone = UR(afl, 4);
+                u8  actually_clone = rand_below(afl, 4);
                 u32 clone_from, clone_to, clone_len;
                 u8 *new_buf;
 
                 if (actually_clone) {
 
                   clone_len = choose_block_len(afl, temp_len);
-                  clone_from = UR(afl, temp_len - clone_len + 1);
+                  clone_from = rand_below(afl, temp_len - clone_len + 1);
 
                 } else {
 
@@ -3890,9 +3908,10 @@ pacemaker_fuzzing:
 
                 }
 
-                clone_to = UR(afl, temp_len);
+                clone_to = rand_below(afl, temp_len);
 
-                new_buf = ck_alloc_nozero(temp_len + clone_len);
+                new_buf = ck_maybe_grow(BUF_PARAMS(out_scratch),
+                                        temp_len + clone_len);
 
                 /* Head */
 
@@ -3904,14 +3923,16 @@ pacemaker_fuzzing:
                   memcpy(new_buf + clone_to, out_buf + clone_from, clone_len);
                 else
                   memset(new_buf + clone_to,
-                         UR(afl, 2) ? UR(afl, 256) : out_buf[UR(afl, temp_len)],
+                         rand_below(afl, 2)
+                             ? rand_below(afl, 256)
+                             : out_buf[rand_below(afl, temp_len)],
                          clone_len);
 
                 /* Tail */
                 memcpy(new_buf + clone_to + clone_len, out_buf + clone_to,
                        temp_len - clone_to);
 
-                ck_free(out_buf);
+                swap_bufs(BUF_PARAMS(out), BUF_PARAMS(out_scratch));
                 out_buf = new_buf;
                 temp_len += clone_len;
                 MOpt_globals.cycles_v2[STAGE_Clone75] += 1;
@@ -3931,10 +3952,10 @@ pacemaker_fuzzing:
 
               copy_len = choose_block_len(afl, temp_len - 1);
 
-              copy_from = UR(afl, temp_len - copy_len + 1);
-              copy_to = UR(afl, temp_len - copy_len + 1);
+              copy_from = rand_below(afl, temp_len - copy_len + 1);
+              copy_to = rand_below(afl, temp_len - copy_len + 1);
 
-              if (UR(afl, 4)) {
+              if (rand_below(afl, 4)) {
 
                 if (copy_from != copy_to)
                   memmove(out_buf + copy_to, out_buf + copy_from, copy_len);
@@ -3942,7 +3963,8 @@ pacemaker_fuzzing:
               } else
 
                 memset(out_buf + copy_to,
-                       UR(afl, 2) ? UR(afl, 256) : out_buf[UR(afl, temp_len)],
+                       rand_below(afl, 2) ? rand_below(afl, 256)
+                                          : out_buf[rand_below(afl, temp_len)],
                        copy_len);
               MOpt_globals.cycles_v2[STAGE_OverWrite75] += 1;
               break;
@@ -3963,7 +3985,7 @@ pacemaker_fuzzing:
         /* out_buf might have been mangled a bit, so let's restore it to its
            original size and shape. */
 
-        if (temp_len < len) out_buf = ck_realloc(out_buf, len);
+        out_buf = ck_maybe_grow(BUF_PARAMS(out), len);
         temp_len = len;
         memcpy(out_buf, in_buf, len);
 
@@ -4041,7 +4063,6 @@ pacemaker_fuzzing:
 
         if (in_buf != orig_in) {
 
-          ck_free(in_buf);
           in_buf = orig_in;
           len = afl->queue_cur->len;
 
@@ -4052,7 +4073,7 @@ pacemaker_fuzzing:
 
         do {
 
-          tid = UR(afl, afl->queued_paths);
+          tid = rand_below(afl, afl->queued_paths);
 
         } while (tid == afl->current_entry);
 
@@ -4086,7 +4107,7 @@ pacemaker_fuzzing:
 
         if (fd < 0) PFATAL("Unable to open '%s'", target->fname);
 
-        new_buf = ck_alloc_nozero(target->len);
+        new_buf = ck_maybe_grow(BUF_PARAMS(in_scratch), target->len);
 
         ck_read(fd, new_buf, target->len, target->fname);
 
@@ -4100,22 +4121,21 @@ pacemaker_fuzzing:
 
         if (f_diff < 0 || l_diff < 2 || f_diff == l_diff) {
 
-          ck_free(new_buf);
           goto retry_splicing_puppet;
 
         }
 
         /* Split somewhere between the first and last differing byte. */
 
-        split_at = f_diff + UR(afl, l_diff - f_diff);
+        split_at = f_diff + rand_below(afl, l_diff - f_diff);
 
         /* Do the thing. */
 
         len = target->len;
         memcpy(new_buf, in_buf, split_at);
+        swap_bufs(BUF_PARAMS(in), BUF_PARAMS(in_scratch));
         in_buf = new_buf;
-        ck_free(out_buf);
-        out_buf = ck_alloc_nozero(len);
+        out_buf = ck_maybe_grow(BUF_PARAMS(out), len);
         memcpy(out_buf, in_buf, len);
 
         goto havoc_stage_puppet;
@@ -4131,7 +4151,8 @@ pacemaker_fuzzing:
 
       if (splice_cycle >= afl->SPLICE_CYCLES_puppet)
         afl->SPLICE_CYCLES_puppet =
-            (UR(afl, SPLICE_CYCLES_puppet_up - SPLICE_CYCLES_puppet_low + 1) +
+            (rand_below(
+                 afl, SPLICE_CYCLES_puppet_up - SPLICE_CYCLES_puppet_low + 1) +
              SPLICE_CYCLES_puppet_low);
 
       afl->splicing_with = -1;
@@ -4149,10 +4170,6 @@ pacemaker_fuzzing:
 
       munmap(orig_in, afl->queue_cur->len);
 
-      if (in_buf != orig_in) ck_free(in_buf);
-      ck_free(out_buf);
-      ck_free(eff_map);
-
       if (afl->key_puppet == 1) {
 
         if (unlikely(
@@ -4374,18 +4391,13 @@ u8 fuzz_one(afl_state_t *afl) {
   int key_val_lv = 0;
 
 #ifdef _AFL_DOCUMENT_MUTATIONS
-  if (afl->do_document == 0) {
 
-    char *fn = alloc_printf("%s/mutations", afl->out_dir);
-    if (fn) {
-
-      afl->do_document = mkdir(fn, 0700);  // if it exists we do not care
-      afl->do_document = 1;
-      ck_free(fn);
-
-    } else
+  u8 path_buf[PATH_MAX];
+  if (afl->do_document == 0) {
 
-      PFATAL("malloc()");
+    snprintf(path_buf, PATH_MAX, "%s/mutations", afl->out_dir);
+    afl->do_document = mkdir(path_buf, 0700);  // if it exists we do not care
+    afl->do_document = 1;
 
   } else {
 
@@ -4413,5 +4425,7 @@ u8 fuzz_one(afl_state_t *afl) {
 
   return key_val_lv;
 
+#undef BUF_PARAMS
+
 }
 
diff --git a/src/afl-fuzz-python.c b/src/afl-fuzz-python.c
index 595c1ed0..12c3a09d 100644
--- a/src/afl-fuzz-python.c
+++ b/src/afl-fuzz-python.c
@@ -28,9 +28,93 @@
 /* Python stuff */
 #ifdef USE_PYTHON
 
-int init_py_module(afl_state_t *afl, u8 *module_name) {
+static void *unsupported(afl_state_t *afl, unsigned int seed) {
 
-  if (!module_name) return 1;
+  FATAL("Python Mutator cannot be called twice yet");
+  return NULL;
+
+}
+
+/* sorry for this makro...
+it just fills in `&py_mutator->something_buf, &py_mutator->something_size`. */
+#define BUF_PARAMS(name)                              \
+  (void **)&((py_mutator_t *)py_mutator)->name##_buf, \
+      &((py_mutator_t *)py_mutator)->name##_size
+
+size_t fuzz_py(void *py_mutator, u8 *buf, size_t buf_size, u8 **out_buf,
+               u8 *add_buf, size_t add_buf_size, size_t max_size) {
+
+  size_t    mutated_size;
+  PyObject *py_args, *py_value;
+  py_args = PyTuple_New(3);
+  py_mutator_t *py = (py_mutator_t *)py_mutator;
+
+  /* buf */
+  py_value = PyByteArray_FromStringAndSize(buf, buf_size);
+  if (!py_value) {
+
+    Py_DECREF(py_args);
+    FATAL("Failed to convert arguments");
+
+  }
+
+  PyTuple_SetItem(py_args, 0, py_value);
+
+  /* add_buf */
+  py_value = PyByteArray_FromStringAndSize(add_buf, add_buf_size);
+  if (!py_value) {
+
+    Py_DECREF(py_args);
+    FATAL("Failed to convert arguments");
+
+  }
+
+  PyTuple_SetItem(py_args, 1, py_value);
+
+  /* max_size */
+#if PY_MAJOR_VERSION >= 3
+  py_value = PyLong_FromLong(max_size);
+#else
+  py_value = PyInt_FromLong(max_size);
+#endif
+  if (!py_value) {
+
+    Py_DECREF(py_args);
+    FATAL("Failed to convert arguments");
+
+  }
+
+  PyTuple_SetItem(py_args, 2, py_value);
+
+  py_value = PyObject_CallObject(py->py_functions[PY_FUNC_FUZZ], py_args);
+
+  Py_DECREF(py_args);
+
+  if (py_value != NULL) {
+
+    mutated_size = PyByteArray_Size(py_value);
+
+    *out_buf = ck_maybe_grow(BUF_PARAMS(fuzz), mutated_size);
+
+    memcpy(*out_buf, PyByteArray_AsString(py_value), mutated_size);
+    Py_DECREF(py_value);
+    return mutated_size;
+
+  } else {
+
+    PyErr_Print();
+    FATAL("python custom fuzz: call failed");
+
+  }
+
+}
+
+static py_mutator_t *init_py_module(afl_state_t *afl, u8 *module_name) {
+
+  if (!module_name) return NULL;
+
+  py_mutator_t *py = calloc(1, sizeof(py_mutator_t));
+  if (!py) PFATAL("Could not allocate memory for python mutator!");
 
   Py_Initialize();
 
@@ -40,17 +124,18 @@ int init_py_module(afl_state_t *afl, u8 *module_name) {
   PyObject *py_name = PyString_FromString(module_name);
 #endif
 
-  afl->py_module = PyImport_Import(py_name);
+  py->py_module = PyImport_Import(py_name);
   Py_DECREF(py_name);
 
-  PyObject * py_module = afl->py_module;
-  PyObject **py_functions = afl->py_functions;
+  PyObject * py_module = py->py_module;
+  PyObject **py_functions = py->py_functions;
 
-  if (afl->py_module != NULL) {
+  if (py_module != NULL) {
 
     u8 py_notrim = 0, py_idx;
-    py_functions[PY_FUNC_INIT] = PyObject_GetAttrString(afl->py_module, "init");
-    py_functions[PY_FUNC_FUZZ] = PyObject_GetAttrString(afl->py_module, "fuzz");
+    /* init, required */
+    py_functions[PY_FUNC_INIT] = PyObject_GetAttrString(py_module, "init");
+    py_functions[PY_FUNC_FUZZ] = PyObject_GetAttrString(py_module, "fuzz");
     py_functions[PY_FUNC_PRE_SAVE] =
         PyObject_GetAttrString(py_module, "pre_save");
     py_functions[PY_FUNC_INIT_TRIM] =
@@ -66,6 +151,7 @@ int init_py_module(afl_state_t *afl, u8 *module_name) {
         PyObject_GetAttrString(py_module, "queue_get");
     py_functions[PY_FUNC_QUEUE_NEW_ENTRY] =
         PyObject_GetAttrString(py_module, "queue_new_entry");
+    py_functions[PY_FUNC_DEINIT] = PyObject_GetAttrString(py_module, "deinit");
 
     for (py_idx = 0; py_idx < PY_FUNC_COUNT; ++py_idx) {
 
@@ -96,7 +182,7 @@ int init_py_module(afl_state_t *afl, u8 *module_name) {
                   "Cannot find/call function with index %d in external "
                   "Python module.\n",
                   py_idx);
-          return 1;
+          return NULL;
 
         }
 
@@ -119,23 +205,27 @@ int init_py_module(afl_state_t *afl, u8 *module_name) {
 
     PyErr_Print();
     fprintf(stderr, "Failed to load \"%s\"\n", module_name);
-    return 1;
+    return NULL;
 
   }
 
-  return 0;
+  return py;
 
 }
 
-void finalize_py_module(afl_state_t *afl) {
+void finalize_py_module(void *py_mutator) {
 
-  if (afl->py_module != NULL) {
+  py_mutator_t *py = (py_mutator_t *)py_mutator;
+
+  if (py->py_module != NULL) {
+
+    deinit_py(py_mutator);
 
     u32 i;
     for (i = 0; i < PY_FUNC_COUNT; ++i)
-      Py_XDECREF(afl->py_functions[i]);
+      Py_XDECREF(py->py_functions[i]);
 
-    Py_DECREF(afl->py_module);
+    Py_DECREF(py->py_module);
 
   }
 
@@ -143,7 +233,8 @@ void finalize_py_module(afl_state_t *afl) {
 
 }
 
-void init_py(afl_state_t *afl, unsigned int seed) {
+static void init_py(afl_state_t *afl, py_mutator_t *py_mutator,
+                    unsigned int seed) {
 
   PyObject *py_args, *py_value;
 
@@ -158,14 +249,14 @@ void init_py(afl_state_t *afl, unsigned int seed) {
   if (!py_value) {
 
     Py_DECREF(py_args);
-    fprintf(stderr, "Cannot convert argument\n");
-    return;
+    FATAL("Cannot convert argument in python init.");
 
   }
 
   PyTuple_SetItem(py_args, 0, py_value);
 
-  py_value = PyObject_CallObject(afl->py_functions[PY_FUNC_INIT], py_args);
+  py_value =
+      PyObject_CallObject(py_mutator->py_functions[PY_FUNC_INIT], py_args);
 
   Py_DECREF(py_args);
 
@@ -173,115 +264,133 @@ void init_py(afl_state_t *afl, unsigned int seed) {
 
     PyErr_Print();
     fprintf(stderr, "Call failed\n");
-    return;
+    FATAL("Custom py mutator INIT failed.");
 
   }
 
 }
 
-size_t fuzz_py(afl_state_t *afl, u8 **buf, size_t buf_size, u8 *add_buf,
-               size_t add_buf_size, size_t max_size) {
+void deinit_py(void *py_mutator) {
 
-  size_t    mutated_size;
   PyObject *py_args, *py_value;
-  py_args = PyTuple_New(3);
 
-  /* buf */
-  py_value = PyByteArray_FromStringAndSize(*buf, buf_size);
-  if (!py_value) {
+  py_args = PyTuple_New(0);
+  py_value = PyObject_CallObject(
+      ((py_mutator_t *)py_mutator)->py_functions[PY_FUNC_DEINIT], py_args);
+  Py_DECREF(py_args);
 
-    Py_DECREF(py_args);
-    FATAL("Failed to convert arguments");
+  if (py_value != NULL) {
+
+    Py_DECREF(py_value);
+
+  } else {
+
+    PyErr_Print();
+    FATAL("Call failed");
 
   }
 
-  PyTuple_SetItem(py_args, 0, py_value);
+}
 
-  /* add_buf */
-  py_value = PyByteArray_FromStringAndSize(add_buf, add_buf_size);
-  if (!py_value) {
+void load_custom_mutator_py(afl_state_t *afl, char *module_name) {
 
-    Py_DECREF(py_args);
-    FATAL("Failed to convert arguments");
+  afl->mutator = ck_alloc(sizeof(struct custom_mutator));
+  afl->mutator->pre_save_buf = NULL;
+  afl->mutator->pre_save_size = 0;
 
-  }
+  afl->mutator->name = module_name;
+  ACTF("Loading Python mutator library from '%s'...", module_name);
 
-  PyTuple_SetItem(py_args, 1, py_value);
+  py_mutator_t *py_mutator;
+  py_mutator = init_py_module(afl, module_name);
+  afl->mutator->data = py_mutator;
+  if (!py_mutator) { FATAL("Failed to load python mutator."); }
 
-  /* max_size */
-#if PY_MAJOR_VERSION >= 3
-  py_value = PyLong_FromLong(max_size);
-#else
-  py_value = PyInt_FromLong(max_size);
-#endif
-  if (!py_value) {
+  PyObject **py_functions = py_mutator->py_functions;
 
-    Py_DECREF(py_args);
-    FATAL("Failed to convert arguments");
+  if (py_functions[PY_FUNC_INIT]) afl->mutator->afl_custom_init = unsupported;
 
-  }
+  if (py_functions[PY_FUNC_DEINIT]) afl->mutator->afl_custom_deinit = deinit_py;
 
-  PyTuple_SetItem(py_args, 2, py_value);
+  /* "afl_custom_fuzz" should not be NULL, but the interface of Python mutator
+     is quite different from the custom mutator. */
+  afl->mutator->afl_custom_fuzz = fuzz_py;
 
-  py_value = PyObject_CallObject(afl->py_functions[PY_FUNC_FUZZ], py_args);
+  if (py_functions[PY_FUNC_PRE_SAVE])
+    afl->mutator->afl_custom_pre_save = pre_save_py;
 
-  Py_DECREF(py_args);
+  if (py_functions[PY_FUNC_INIT_TRIM])
+    afl->mutator->afl_custom_init_trim = init_trim_py;
 
-  if (py_value != NULL) {
+  if (py_functions[PY_FUNC_POST_TRIM])
+    afl->mutator->afl_custom_post_trim = post_trim_py;
 
-    mutated_size = PyByteArray_Size(py_value);
-    if (buf_size < mutated_size) *buf = ck_realloc(*buf, mutated_size);
+  if (py_functions[PY_FUNC_TRIM]) afl->mutator->afl_custom_trim = trim_py;
 
-    memcpy(*buf, PyByteArray_AsString(py_value), mutated_size);
-    Py_DECREF(py_value);
-    return mutated_size;
+  if (py_functions[PY_FUNC_HAVOC_MUTATION])
+    afl->mutator->afl_custom_havoc_mutation = havoc_mutation_py;
 
-  } else {
+  if (py_functions[PY_FUNC_HAVOC_MUTATION_PROBABILITY])
+    afl->mutator->afl_custom_havoc_mutation_probability =
+        havoc_mutation_probability_py;
 
-    PyErr_Print();
-    FATAL("Call failed");
+  if (py_functions[PY_FUNC_QUEUE_GET])
+    afl->mutator->afl_custom_queue_get = queue_get_py;
 
-  }
+  if (py_functions[PY_FUNC_QUEUE_NEW_ENTRY])
+    afl->mutator->afl_custom_queue_new_entry = queue_new_entry_py;
+
+  OKF("Python mutator '%s' installed successfully.", module_name);
+
+  /* Initialize the custom mutator */
+  init_py(afl, py_mutator, rand_below(afl, 0xFFFFFFFF));
 
 }
 
-size_t pre_save_py(afl_state_t *afl, u8 *buf, size_t buf_size, u8 **out_buf) {
+size_t pre_save_py(void *py_mutator, u8 *buf, size_t buf_size, u8 **out_buf) {
+
+  size_t        py_out_buf_size;
+  PyObject *    py_args, *py_value;
+  py_mutator_t *py = (py_mutator_t *)py_mutator;
 
-  size_t    out_buf_size;
-  PyObject *py_args, *py_value;
   py_args = PyTuple_New(1);
   py_value = PyByteArray_FromStringAndSize(buf, buf_size);
   if (!py_value) {
 
     Py_DECREF(py_args);
-    FATAL("Failed to convert arguments");
+    FATAL("Failed to convert arguments in custom pre_save");
 
   }
 
   PyTuple_SetItem(py_args, 0, py_value);
 
-  py_value = PyObject_CallObject(afl->py_functions[PY_FUNC_PRE_SAVE], py_args);
+  py_value = PyObject_CallObject(
+      ((py_mutator_t *)py_mutator)->py_functions[PY_FUNC_PRE_SAVE], py_args);
 
   Py_DECREF(py_args);
 
   if (py_value != NULL) {
 
-    out_buf_size = PyByteArray_Size(py_value);
-    *out_buf = malloc(out_buf_size);
-    memcpy(*out_buf, PyByteArray_AsString(py_value), out_buf_size);
+    py_out_buf_size = PyByteArray_Size(py_value);
+
+    ck_maybe_grow(BUF_PARAMS(pre_save), py_out_buf_size);
+
+    memcpy(py->pre_save_buf, PyByteArray_AsString(py_value), py_out_buf_size);
     Py_DECREF(py_value);
-    return out_buf_size;
+
+    *out_buf = py->pre_save_buf;
+    return py_out_buf_size;
 
   } else {
 
     PyErr_Print();
-    FATAL("Call failed");
+    FATAL("Python custom mutator: pre_save call failed.");
 
   }
 
 }
 
-u32 init_trim_py(afl_state_t *afl, u8 *buf, size_t buf_size) {
+s32 init_trim_py(void *py_mutator, u8 *buf, size_t buf_size) {
 
   PyObject *py_args, *py_value;
 
@@ -296,7 +405,8 @@ u32 init_trim_py(afl_state_t *afl, u8 *buf, size_t buf_size) {
 
   PyTuple_SetItem(py_args, 0, py_value);
 
-  py_value = PyObject_CallObject(afl->py_functions[PY_FUNC_INIT_TRIM], py_args);
+  py_value = PyObject_CallObject(
+      ((py_mutator_t *)py_mutator)->py_functions[PY_FUNC_INIT_TRIM], py_args);
   Py_DECREF(py_args);
 
   if (py_value != NULL) {
@@ -318,7 +428,7 @@ u32 init_trim_py(afl_state_t *afl, u8 *buf, size_t buf_size) {
 
 }
 
-u32 post_trim_py(afl_state_t *afl, u8 success) {
+s32 post_trim_py(void *py_mutator, u8 success) {
 
   PyObject *py_args, *py_value;
 
@@ -334,7 +444,8 @@ u32 post_trim_py(afl_state_t *afl, u8 success) {
 
   PyTuple_SetItem(py_args, 0, py_value);
 
-  py_value = PyObject_CallObject(afl->py_functions[PY_FUNC_POST_TRIM], py_args);
+  py_value = PyObject_CallObject(
+      ((py_mutator_t *)py_mutator)->py_functions[PY_FUNC_POST_TRIM], py_args);
   Py_DECREF(py_args);
 
   if (py_value != NULL) {
@@ -356,19 +467,21 @@ u32 post_trim_py(afl_state_t *afl, u8 success) {
 
 }
 
-void trim_py(afl_state_t *afl, u8 **out_buf, size_t *out_buf_size) {
+size_t trim_py(void *py_mutator, u8 **out_buf) {
 
   PyObject *py_args, *py_value;
+  size_t    ret;
 
   py_args = PyTuple_New(0);
-  py_value = PyObject_CallObject(afl->py_functions[PY_FUNC_TRIM], py_args);
+  py_value = PyObject_CallObject(
+      ((py_mutator_t *)py_mutator)->py_functions[PY_FUNC_TRIM], py_args);
   Py_DECREF(py_args);
 
   if (py_value != NULL) {
 
-    *out_buf_size = PyByteArray_Size(py_value);
-    *out_buf = malloc(*out_buf_size);
-    memcpy(*out_buf, PyByteArray_AsString(py_value), *out_buf_size);
+    ret = PyByteArray_Size(py_value);
+    *out_buf = ck_maybe_grow(BUF_PARAMS(trim), ret);
+    memcpy(*out_buf, PyByteArray_AsString(py_value), ret);
     Py_DECREF(py_value);
 
   } else {
@@ -378,17 +491,19 @@ void trim_py(afl_state_t *afl, u8 **out_buf, size_t *out_buf_size) {
 
   }
 
+  return ret;
+
 }
 
-size_t havoc_mutation_py(afl_state_t *afl, u8 **buf, size_t buf_size,
-                         size_t max_size) {
+size_t havoc_mutation_py(void *py_mutator, u8 *buf, size_t buf_size,
+                         u8 **out_buf, size_t max_size) {
 
   size_t    mutated_size;
   PyObject *py_args, *py_value;
   py_args = PyTuple_New(2);
 
   /* buf */
-  py_value = PyByteArray_FromStringAndSize(*buf, buf_size);
+  py_value = PyByteArray_FromStringAndSize(buf, buf_size);
   if (!py_value) {
 
     Py_DECREF(py_args);
@@ -413,17 +528,28 @@ size_t havoc_mutation_py(afl_state_t *afl, u8 **buf, size_t buf_size,
 
   PyTuple_SetItem(py_args, 1, py_value);
 
-  py_value =
-      PyObject_CallObject(afl->py_functions[PY_FUNC_HAVOC_MUTATION], py_args);
+  py_value = PyObject_CallObject(
+      ((py_mutator_t *)py_mutator)->py_functions[PY_FUNC_HAVOC_MUTATION],
+      py_args);
 
   Py_DECREF(py_args);
 
   if (py_value != NULL) {
 
     mutated_size = PyByteArray_Size(py_value);
-    if (buf_size < mutated_size) *buf = ck_realloc(*buf, mutated_size);
+    if (mutated_size <= buf_size) {
+
+      /* We reuse the input buf here. */
+      *out_buf = buf;
 
-    memcpy(*buf, PyByteArray_AsString(py_value), mutated_size);
+    } else {
+
+      /* A new buf is needed... */
+      *out_buf = ck_maybe_grow(BUF_PARAMS(havoc), mutated_size);
+
+    }
+
+    memcpy(*out_buf, PyByteArray_AsString(py_value), mutated_size);
 
     Py_DECREF(py_value);
     return mutated_size;
@@ -437,13 +563,15 @@ size_t havoc_mutation_py(afl_state_t *afl, u8 **buf, size_t buf_size,
 
 }
 
-u8 havoc_mutation_probability_py(afl_state_t *afl) {
+u8 havoc_mutation_probability_py(void *py_mutator) {
 
   PyObject *py_args, *py_value;
 
   py_args = PyTuple_New(0);
   py_value = PyObject_CallObject(
-      afl->py_functions[PY_FUNC_HAVOC_MUTATION_PROBABILITY], py_args);
+      ((py_mutator_t *)py_mutator)
+          ->py_functions[PY_FUNC_HAVOC_MUTATION_PROBABILITY],
+      py_args);
   Py_DECREF(py_args);
 
   if (py_value != NULL) {
@@ -461,7 +589,7 @@ u8 havoc_mutation_probability_py(afl_state_t *afl) {
 
 }
 
-u8 queue_get_py(afl_state_t *afl, const u8 *filename) {
+u8 queue_get_py(void *py_mutator, const u8 *filename) {
 
   PyObject *py_args, *py_value;
 
@@ -483,7 +611,8 @@ u8 queue_get_py(afl_state_t *afl, const u8 *filename) {
   PyTuple_SetItem(py_args, 0, py_value);
 
   // Call Python function
-  py_value = PyObject_CallObject(afl->py_functions[PY_FUNC_QUEUE_GET], py_args);
+  py_value = PyObject_CallObject(
+      ((py_mutator_t *)py_mutator)->py_functions[PY_FUNC_QUEUE_GET], py_args);
   Py_DECREF(py_args);
 
   if (py_value != NULL) {
@@ -509,7 +638,7 @@ u8 queue_get_py(afl_state_t *afl, const u8 *filename) {
 
 }
 
-void queue_new_entry_py(afl_state_t *afl, const u8 *filename_new_queue,
+void queue_new_entry_py(void *py_mutator, const u8 *filename_new_queue,
                         const u8 *filename_orig_queue) {
 
   PyObject *py_args, *py_value;
@@ -552,8 +681,9 @@ void queue_new_entry_py(afl_state_t *afl, const u8 *filename_new_queue,
   PyTuple_SetItem(py_args, 1, py_value);
 
   // Call
-  py_value =
-      PyObject_CallObject(afl->py_functions[PY_FUNC_QUEUE_NEW_ENTRY], py_args);
+  py_value = PyObject_CallObject(
+      ((py_mutator_t *)py_mutator)->py_functions[PY_FUNC_QUEUE_NEW_ENTRY],
+      py_args);
   Py_DECREF(py_args);
 
   if (py_value == NULL) {
@@ -565,5 +695,7 @@ void queue_new_entry_py(afl_state_t *afl, const u8 *filename_new_queue,
 
 }
 
+#undef BUF_PARAMS
+
 #endif                                                        /* USE_PYTHON */
 
diff --git a/src/afl-fuzz-queue.c b/src/afl-fuzz-queue.c
index cfeab798..346c2639 100644
--- a/src/afl-fuzz-queue.c
+++ b/src/afl-fuzz-queue.c
@@ -23,6 +23,7 @@
  */
 
 #include "afl-fuzz.h"
+#include <limits.h>
 
 /* Mark deterministic checks as done for a particular queue entry. We use the
    .state file to avoid repeating deterministic fuzzing when resuming aborted
@@ -30,18 +31,16 @@
 
 void mark_as_det_done(afl_state_t *afl, struct queue_entry *q) {
 
-  u8 *fn = strrchr(q->fname, '/');
+  u8  fn[PATH_MAX];
   s32 fd;
 
-  fn = alloc_printf("%s/queue/.state/deterministic_done/%s", afl->out_dir,
-                    fn + 1);
+  snprintf(fn, PATH_MAX, "%s/queue/.state/deterministic_done/%s", afl->out_dir,
+           strrchr(q->fname, '/') + 1);
 
   fd = open(fn, O_WRONLY | O_CREAT | O_EXCL, 0600);
   if (fd < 0) PFATAL("Unable to create '%s'", fn);
   close(fd);
 
-  ck_free(fn);
-
   q->passed_det = 1;
 
 }
@@ -51,10 +50,13 @@ void mark_as_det_done(afl_state_t *afl, struct queue_entry *q) {
 
 void mark_as_variable(afl_state_t *afl, struct queue_entry *q) {
 
-  u8 *fn = strrchr(q->fname, '/') + 1, *ldest;
+  u8 fn[PATH_MAX];
+  u8 ldest[PATH_MAX];
+
+  u8 *fn_name = strrchr(q->fname, '/') + 1;
 
-  ldest = alloc_printf("../../%s", fn);
-  fn = alloc_printf("%s/queue/.state/variable_behavior/%s", afl->out_dir, fn);
+  sprintf(ldest, "../../%s", fn_name);
+  sprintf(fn, "%s/queue/.state/variable_behavior/%s", afl->out_dir, fn_name);
 
   if (symlink(ldest, fn)) {
 
@@ -64,9 +66,6 @@ void mark_as_variable(afl_state_t *afl, struct queue_entry *q) {
 
   }
 
-  ck_free(ldest);
-  ck_free(fn);
-
   q->var_behavior = 1;
 
 }
@@ -76,14 +75,14 @@ void mark_as_variable(afl_state_t *afl, struct queue_entry *q) {
 
 void mark_as_redundant(afl_state_t *afl, struct queue_entry *q, u8 state) {
 
-  u8 *fn;
+  u8 fn[PATH_MAX];
 
   if (state == q->fs_redundant) return;
 
   q->fs_redundant = state;
 
-  fn = strrchr(q->fname, '/');
-  fn = alloc_printf("%s/queue/.state/redundant_edges/%s", afl->out_dir, fn + 1);
+  sprintf(fn, "%s/queue/.state/redundant_edges/%s", afl->out_dir,
+          strrchr(q->fname, '/') + 1);
 
   if (state) {
 
@@ -99,8 +98,6 @@ void mark_as_redundant(afl_state_t *afl, struct queue_entry *q, u8 state) {
 
   }
 
-  ck_free(fn);
-
 }
 
 /* Append new test case to the queue. */
@@ -114,6 +111,7 @@ void add_to_queue(afl_state_t *afl, u8 *fname, u32 len, u8 passed_det) {
   q->depth = afl->cur_depth + 1;
   q->passed_det = passed_det;
   q->n_fuzz = 1;
+  q->trace_mini = NULL;
 
   if (q->depth > afl->max_depth) afl->max_depth = q->depth;
 
@@ -147,7 +145,8 @@ void add_to_queue(afl_state_t *afl, u8 *fname, u32 len, u8 passed_det) {
     /* At the initialization stage, queue_cur is NULL */
     if (afl->queue_cur) fname_orig = afl->queue_cur->fname;
 
-    afl->mutator->afl_custom_queue_new_entry(afl, fname, fname_orig);
+    afl->mutator->afl_custom_queue_new_entry(afl->mutator->data, fname,
+                                             fname_orig);
 
   }
 
@@ -185,35 +184,50 @@ void destroy_queue(afl_state_t *afl) {
 void update_bitmap_score(afl_state_t *afl, struct queue_entry *q) {
 
   u32 i;
-  u64 fav_factor = q->exec_us * q->len;
-  u64 fuzz_p2 = next_p2(q->n_fuzz);
+  u64 fav_factor;
+  u64 fuzz_p2 = next_pow2(q->n_fuzz);
+
+  if (afl->schedule == MMOPT || afl->schedule == RARE ||
+      unlikely(afl->fixed_seed))
+    fav_factor = q->len << 2;
+  else
+    fav_factor = q->exec_us * q->len;
 
   /* For every byte set in afl->fsrv.trace_bits[], see if there is a previous
      winner, and how it compares to us. */
-
-  for (i = 0; i < MAP_SIZE; ++i)
+  for (i = 0; i < afl->fsrv.map_size; ++i)
 
     if (afl->fsrv.trace_bits[i]) {
 
       if (afl->top_rated[i]) {
 
         /* Faster-executing or smaller test cases are favored. */
-        u64 top_rated_fuzz_p2 = next_p2(afl->top_rated[i]->n_fuzz);
-        u64 top_rated_fav_factor =
-            afl->top_rated[i]->exec_us * afl->top_rated[i]->len;
+        u64 top_rated_fav_factor;
+        u64 top_rated_fuzz_p2 = next_pow2(afl->top_rated[i]->n_fuzz);
 
-        if (fuzz_p2 > top_rated_fuzz_p2) {
+        if (afl->schedule == MMOPT || afl->schedule == RARE ||
+            unlikely(afl->fixed_seed))
+          top_rated_fav_factor = afl->top_rated[i]->len << 2;
+        else
+          top_rated_fav_factor =
+              afl->top_rated[i]->exec_us * afl->top_rated[i]->len;
 
+        if (fuzz_p2 > top_rated_fuzz_p2)
           continue;
+        else if (fuzz_p2 == top_rated_fuzz_p2)
+          if (fav_factor > top_rated_fav_factor) continue;
 
-        } else if (fuzz_p2 == top_rated_fuzz_p2) {
+        if (afl->schedule == MMOPT || afl->schedule == RARE ||
+            unlikely(afl->fixed_seed)) {
 
-          if (fav_factor > top_rated_fav_factor) continue;
+          if (fav_factor > afl->top_rated[i]->len << 2) continue;
 
-        }
+        } else {
 
-        if (fav_factor > afl->top_rated[i]->exec_us * afl->top_rated[i]->len)
-          continue;
+          if (fav_factor > afl->top_rated[i]->exec_us * afl->top_rated[i]->len)
+            continue;
+
+        }
 
         /* Looks like we're going to win. Decrease ref count for the
            previous winner, discard its afl->fsrv.trace_bits[] if necessary. */
@@ -234,8 +248,10 @@ void update_bitmap_score(afl_state_t *afl, struct queue_entry *q) {
 
       if (!q->trace_mini) {
 
-        q->trace_mini = ck_alloc(MAP_SIZE >> 3);
-        minimize_bits(q->trace_mini, afl->fsrv.trace_bits);
+        u32 len = (afl->fsrv.map_size >> 3);
+        if (len == 0) len = 1;
+        q->trace_mini = ck_alloc(len);
+        minimize_bits(afl, q->trace_mini, afl->fsrv.trace_bits);
 
       }
 
@@ -254,14 +270,17 @@ void update_bitmap_score(afl_state_t *afl, struct queue_entry *q) {
 void cull_queue(afl_state_t *afl) {
 
   struct queue_entry *q;
-  static u8           temp_v[MAP_SIZE >> 3];
+  u32                 len = (afl->fsrv.map_size >> 3);
   u32                 i;
+  u8                  temp_v[MAP_SIZE >> 3];
+
+  if (len == 0) len = 1;
 
   if (afl->dumb_mode || !afl->score_changed) return;
 
   afl->score_changed = 0;
 
-  memset(temp_v, 255, MAP_SIZE >> 3);
+  memset(temp_v, 255, len);
 
   afl->queued_favored = 0;
   afl->pending_favored = 0;
@@ -278,10 +297,10 @@ void cull_queue(afl_state_t *afl) {
   /* Let's see if anything in the bitmap isn't captured in temp_v.
      If yes, and if it has a afl->top_rated[] contender, let's use it. */
 
-  for (i = 0; i < MAP_SIZE; ++i)
+  for (i = 0; i < afl->fsrv.map_size; ++i)
     if (afl->top_rated[i] && (temp_v[i >> 3] & (1 << (i & 7)))) {
 
-      u32 j = MAP_SIZE >> 3;
+      u32 j = len;
 
       /* Remove all bits belonging to the current entry from temp_v. */
 
@@ -328,7 +347,8 @@ u32 calculate_score(afl_state_t *afl, struct queue_entry *q) {
   // Longer execution time means longer work on the input, the deeper in
   // coverage, the better the fuzzing, right? -mh
 
-  if (afl->schedule != MMOPT) {
+  if (afl->schedule != MMOPT && afl->schedule != RARE &&
+      likely(!afl->fixed_seed)) {
 
     if (q->exec_us * 0.1 > avg_exec_us)
       perf_score = 10;
@@ -438,7 +458,7 @@ u32 calculate_score(afl_state_t *afl, struct queue_entry *q) {
       if (q->fuzz_level < 16)
         factor = ((u32)(1 << q->fuzz_level)) / (fuzz == 0 ? 1 : fuzz);
       else
-        factor = MAX_FACTOR / (fuzz == 0 ? 1 : next_p2(fuzz));
+        factor = MAX_FACTOR / (fuzz == 0 ? 1 : next_pow2(fuzz));
       break;
 
     case LIN: factor = q->fuzz_level / (fuzz == 0 ? 1 : fuzz); break;
@@ -448,8 +468,29 @@ u32 calculate_score(afl_state_t *afl, struct queue_entry *q) {
       break;
 
     case MMOPT:
+      /* -- this was a more complex setup, which is good, but competed with
+         -- rare. the simpler algo however is good when rare is not.
+        // the newer the entry, the higher the pref_score
+        perf_score *= (1 + (double)((double)q->depth /
+        (double)afl->queued_paths));
+        // with special focus on the last 8 entries
+        if (afl->max_depth - q->depth < 8) perf_score *= (1 + ((8 -
+        (afl->max_depth - q->depth)) / 5));
+      */
+      // put focus on the last 5 entries
+      if (afl->max_depth - q->depth < 5) perf_score *= 2;
+
+      break;
+
+    case RARE:
 
-      if (afl->max_depth - q->depth < 5) perf_score *= 1.5;
+      // increase the score for every bitmap byte for which this entry
+      // is the top contender
+      perf_score += (q->tc_ref * 10);
+      // the more often fuzz result paths are equal to this queue entry,
+      // reduce its value
+      perf_score *=
+          (1 - (double)((double)q->n_fuzz / (double)afl->total_execs));
 
       break;
 
diff --git a/src/afl-fuzz-redqueen.c b/src/afl-fuzz-redqueen.c
index c8d54ce2..ba24890b 100644
--- a/src/afl-fuzz-redqueen.c
+++ b/src/afl-fuzz-redqueen.c
@@ -88,7 +88,7 @@ static u8 get_exec_checksum(afl_state_t *afl, u8 *buf, u32 len, u32 *cksum) {
 
   if (unlikely(common_fuzz_stuff(afl, buf, len))) return 1;
 
-  *cksum = hash32(afl->fsrv.trace_bits, MAP_SIZE, HASH_CONST);
+  *cksum = hash32(afl->fsrv.trace_bits, afl->fsrv.map_size, HASH_CONST);
   return 0;
 
 }
@@ -97,7 +97,7 @@ static void rand_replace(afl_state_t *afl, u8 *buf, u32 len) {
 
   u32 i;
   for (i = 0; i < len; ++i)
-    buf[i] = UR(afl, 256);
+    buf[i] = rand_below(afl, 256);
 
 }
 
@@ -337,7 +337,7 @@ static void try_to_add_to_dict(afl_state_t *afl, u64 v, u8 shape) {
 
   }
 
-  maybe_add_auto(afl, (u8 *)&v, shape);
+  maybe_add_auto((u8 *)afl, (u8 *)&v, shape);
 
   u64 rev;
   switch (shape) {
@@ -345,15 +345,15 @@ static void try_to_add_to_dict(afl_state_t *afl, u64 v, u8 shape) {
     case 1: break;
     case 2:
       rev = SWAP16((u16)v);
-      maybe_add_auto(afl, (u8 *)&rev, shape);
+      maybe_add_auto((u8 *)afl, (u8 *)&rev, shape);
       break;
     case 4:
       rev = SWAP32((u32)v);
-      maybe_add_auto(afl, (u8 *)&rev, shape);
+      maybe_add_auto((u8 *)afl, (u8 *)&rev, shape);
       break;
     case 8:
       rev = SWAP64(v);
-      maybe_add_auto(afl, (u8 *)&rev, shape);
+      maybe_add_auto((u8 *)afl, (u8 *)&rev, shape);
       break;
 
   }
@@ -511,8 +511,8 @@ static u8 rtn_fuzz(afl_state_t *afl, u32 key, u8 *orig_buf, u8 *buf, u32 len) {
     if (fails == 8) {
 
       if (afl->pass_stats[key].total == 0) {
-        maybe_add_auto(afl, o->v0, SHAPE_BYTES(h->shape));
-        maybe_add_auto(afl, o->v1, SHAPE_BYTES(h->shape));
+        maybe_add_auto((u8 *)afl, o->v0, SHAPE_BYTES(h->shape));
+        maybe_add_auto((u8 *)afl, o->v1, SHAPE_BYTES(h->shape));
       }
 
     }
@@ -569,9 +569,10 @@ u8 input_to_state_stage(afl_state_t *afl, u8 *orig_buf, u8 *buf, u32 len,
       afl->shm.cmp_map->headers[k].hits = 0;
     
     if (afl->shm.cmp_map->headers[k].type == CMP_TYPE_INS)
-      afl->stage_max += MIN(afl->shm.cmp_map->headers[k].hits, CMP_MAP_H);
+      afl->stage_max += MIN((u32)afl->shm.cmp_map->headers[k].hits, CMP_MAP_H);
     else
-      afl->stage_max += MIN(afl->shm.cmp_map->headers[k].hits, CMP_MAP_RTN_H);
+      afl->stage_max +=
+          MIN((u32)afl->shm.cmp_map->headers[k].hits, CMP_MAP_RTN_H);
 
   }
 
diff --git a/src/afl-fuzz-run.c b/src/afl-fuzz-run.c
index cdec75e8..1ddd7e1a 100644
--- a/src/afl-fuzz-run.c
+++ b/src/afl-fuzz-run.c
@@ -27,78 +27,62 @@
 #include <sys/time.h>
 #include <signal.h>
 
-/* Execute target application, monitoring for timeouts. Return status
-   information. The called program will update afl->fsrv.trace_bits[]. */
-
-void timeout_handle(union sigval timer_data) {
+#include "cmplog.h"
 
-  pid_t child_pid = timer_data.sival_int;
-  if (child_pid > 0) kill(child_pid, SIGKILL);
-
-}
+/* Execute target application, monitoring for timeouts. Return status
+   information. The called program will update afl->fsrv->trace_bits. */
 
-u8 run_target(afl_state_t *afl, u32 timeout) {
+u8 run_target(afl_state_t *afl, afl_forkserver_t *fsrv, u32 timeout) {
 
   s32 res;
-  int sret;
-
-  fd_set readfds;
-
-  static struct timeval it;
-  static u32            prev_timed_out = 0;
+  u32 exec_ms;
 
   int status = 0;
   u32 tb4;
 
-  afl->fsrv.child_timed_out = 0;
+  fsrv->child_timed_out = 0;
 
-  /* After this memset, afl->fsrv.trace_bits[] are effectively volatile, so we
+  /* After this memset, fsrv->trace_bits[] are effectively volatile, so we
      must prevent any earlier operations from venturing into that
      territory. */
 
-  memset(afl->fsrv.trace_bits, 0, MAP_SIZE);
+  memset(fsrv->trace_bits, 0, fsrv->map_size);
 
   MEM_BARRIER();
-
+  
   /* we have the fork server (or faux server) up and running, so simply
       tell it to have at it, and then read back PID. */
 
-  if ((res = write(afl->fsrv.fsrv_ctl_fd, &prev_timed_out, 4)) != 4) {
+  if ((res = write(fsrv->fsrv_ctl_fd, &fsrv->prev_timed_out, 4)) != 4) {
 
     if (afl->stop_soon) return 0;
     RPFATAL(res, "Unable to request new process from fork server (OOM?)");
 
   }
 
-  if ((res = read(afl->fsrv.fsrv_st_fd, &afl->fsrv.child_pid, 4)) != 4) {
+  if ((res = read(fsrv->fsrv_st_fd, &fsrv->child_pid, 4)) != 4) {
 
     if (afl->stop_soon) return 0;
     RPFATAL(res, "Unable to request new process from fork server (OOM?)");
 
   }
 
-  if (afl->fsrv.child_pid <= 0) FATAL("Fork server is misbehaving (OOM?)");
+  if (fsrv->child_pid <= 0) FATAL("Fork server is misbehaving (OOM?)");
 
-  /* use select to monitor the forkserver for timeouts. */
+  exec_ms = read_timed(fsrv->fsrv_st_fd, &status, 4, timeout, &afl->stop_soon);
 
-  FD_ZERO(&readfds);
-  FD_SET(afl->fsrv.fsrv_st_fd, &readfds);
-  it.tv_sec = ((timeout) / 1000);
-  it.tv_usec = ((timeout) % 1000) * 1000;
-
-  sret = select(afl->fsrv.fsrv_st_fd + 1, &readfds, NULL, NULL, &it);
-
-  if (sret == 0) {
+  if (exec_ms > timeout) {
 
     /* If there was no response from forkserver after timeout seconds,
     we kill the child. The forkserver should inform us afterwards */
 
-    kill(afl->fsrv.child_pid, SIGKILL);
-    afl->fsrv.child_timed_out = 1;
+    kill(fsrv->child_pid, SIGKILL);
+    fsrv->child_timed_out = 1;
+    if (read(fsrv->fsrv_st_fd, &status, 4) < 4) exec_ms = 0;
 
   }
 
-  if ((res = read(afl->fsrv.fsrv_st_fd, &status, 4)) != 4) {
+  if (!exec_ms) {
 
     if (afl->stop_soon) return 0;
     SAYF("\n" cLRD "[-] " cRST
@@ -121,30 +105,30 @@ u8 run_target(afl_state_t *afl, u32 timeout) {
          "\n\n"
          "If all else fails you can disable the fork server via "
          "AFL_NO_FORKSRV=1.\n",
-         afl->fsrv.mem_limit);
+         fsrv->mem_limit);
     RPFATAL(res, "Unable to communicate with fork server");
 
   }
 
-  if (!WIFSTOPPED(status)) afl->fsrv.child_pid = 0;
+  if (!WIFSTOPPED(status)) fsrv->child_pid = 0;
 
   ++afl->total_execs;
 
-  /* Any subsequent operations on afl->fsrv.trace_bits must not be moved by the
-     compiler below this point. Past this location, afl->fsrv.trace_bits[]
+  /* Any subsequent operations on fsrv->trace_bits must not be moved by the
+     compiler below this point. Past this location, fsrv->trace_bits[]
      behave very normally and do not have to be treated as volatile. */
 
   MEM_BARRIER();
 
-  tb4 = *(u32 *)afl->fsrv.trace_bits;
+  tb4 = *(u32 *)fsrv->trace_bits;
 
 #ifdef WORD_SIZE_64
-  classify_counts((u64 *)afl->fsrv.trace_bits);
+  classify_counts(afl, (u64 *)fsrv->trace_bits);
 #else
-  classify_counts((u32 *)afl->fsrv.trace_bits);
+  classify_counts(afl, (u32 *)fsrv->trace_bits);
 #endif                                                     /* ^WORD_SIZE_64 */
 
-  prev_timed_out = afl->fsrv.child_timed_out;
+  fsrv->prev_timed_out = fsrv->child_timed_out;
 
   /* Report outcome to caller. */
 
@@ -152,7 +136,7 @@ u8 run_target(afl_state_t *afl, u32 timeout) {
 
     afl->kill_signal = WTERMSIG(status);
 
-    if (afl->fsrv.child_timed_out && afl->kill_signal == SIGKILL)
+    if (fsrv->child_timed_out && afl->kill_signal == SIGKILL)
       return FAULT_TMOUT;
 
     return FAULT_CRASH;
@@ -162,7 +146,7 @@ u8 run_target(afl_state_t *afl, u32 timeout) {
   /* A somewhat nasty hack for MSAN, which doesn't support abort_on_error and
      must use a special exit code. */
 
-  if (afl->fsrv.uses_asan && WEXITSTATUS(status) == MSAN_ERROR) {
+  if (fsrv->uses_asan && WEXITSTATUS(status) == MSAN_ERROR) {
 
     afl->kill_signal = 0;
     return FAULT_CRASH;
@@ -185,20 +169,16 @@ void write_to_testcase(afl_state_t *afl, void *mem, u32 len) {
   s32 fd = afl->fsrv.out_fd;
 
 #ifdef _AFL_DOCUMENT_MUTATIONS
-  s32   doc_fd;
-  char *fn = alloc_printf("%s/mutations/%09u:%s", afl->out_dir,
+  s32  doc_fd;
+  char fn[PATH_MAX];
+  snprintf(fn, PATH_MAX, ("%s/mutations/%09u:%s", afl->out_dir,
                           afl->document_counter++, describe_op(afl, 0));
-  if (fn != NULL) {
-
-    if ((doc_fd = open(fn, O_WRONLY | O_CREAT | O_TRUNC, 0600)) >= 0) {
-
-      if (write(doc_fd, mem, len) != len)
-        PFATAL("write to mutation file failed: %s", fn);
-      close(doc_fd);
 
-    }
+  if ((doc_fd = open(fn, O_WRONLY | O_CREAT | O_TRUNC, 0600)) >= 0) {
 
-    ck_free(fn);
+    if (write(doc_fd, mem, len) != len)
+      PFATAL("write to mutation file failed: %s", fn);
+    close(doc_fd);
 
   }
 
@@ -223,16 +203,22 @@ void write_to_testcase(afl_state_t *afl, void *mem, u32 len) {
 
     lseek(fd, 0, SEEK_SET);
 
-  if (afl->mutator && afl->mutator->afl_custom_pre_save) {
+  if (unlikely(afl->mutator && afl->mutator->afl_custom_pre_save)) {
+
+    u8 *new_buf = NULL;
+
+    size_t new_size = afl->mutator->afl_custom_pre_save(afl->mutator->data, mem,
+                                                        len, &new_buf);
+
+    if (unlikely(!new_buf))
+      FATAL("Custom_pre_save failed (ret: %lu)", (long unsigned)new_size);
 
-    u8 *   new_data;
-    size_t new_size =
-        afl->mutator->afl_custom_pre_save(afl, mem, len, &new_data);
-    ck_write(fd, new_data, new_size, afl->fsrv.out_file);
-    ck_free(new_data);
+    /* everything as planned. use the new data. */
+    ck_write(fd, new_buf, new_size, afl->fsrv.out_file);
 
   } else {
 
+    /* boring uncustom. */
     ck_write(fd, mem, len, afl->fsrv.out_file);
 
   }
@@ -299,8 +285,6 @@ static void write_with_gap(afl_state_t *afl, void *mem, u32 len, u32 skip_at,
 u8 calibrate_case(afl_state_t *afl, struct queue_entry *q, u8 *use_mem,
                   u32 handicap, u8 from_queue) {
 
-  static u8 first_trace[MAP_SIZE];
-
   u8 fault = 0, new_bits = 0, var_detected = 0,
      first_run = (q->exec_cksum == 0);
 
@@ -326,12 +310,22 @@ u8 calibrate_case(afl_state_t *afl, struct queue_entry *q, u8 *use_mem,
   /* Make sure the forkserver is up before we do anything, and let's not
      count its spin-up time toward binary calibration. */
 
-  if (!afl->fsrv.fsrv_pid) afl_fsrv_start(&afl->fsrv, afl->argv);
-  if (afl->dumb_mode != 1 && !afl->no_forkserver && !afl->cmplog_fsrv_pid &&
-      afl->shm.cmplog_mode)
-    init_cmplog_forkserver(afl);
+  if (!afl->fsrv.fsrv_pid) {
+
+    if (afl->fsrv.cmplog_binary &&
+        afl->fsrv.init_child_func != cmplog_exec_child) {
+
+      FATAL("BUG in afl-fuzz detected. Cmplog mode not set correctly.");
+
+    }
+
+    afl_fsrv_start(&afl->fsrv, afl->argv, &afl->stop_soon,
+                   afl->afl_env.afl_debug_child_output);
+
+  }
 
-  if (q->exec_cksum) memcpy(first_trace, afl->fsrv.trace_bits, MAP_SIZE);
+  if (q->exec_cksum)
+    memcpy(afl->first_trace, afl->fsrv.trace_bits, afl->fsrv.map_size);
 
   start_us = get_cur_time_us();
 
@@ -344,7 +338,7 @@ u8 calibrate_case(afl_state_t *afl, struct queue_entry *q, u8 *use_mem,
 
     write_to_testcase(afl, use_mem, q->len);
 
-    fault = run_target(afl, use_tmout);
+    fault = run_target(afl, &afl->fsrv, use_tmout);
 
     /* afl->stop_soon is set by the handler for Ctrl+C. When it's pressed,
        we want to bail out quickly. */
@@ -352,14 +346,14 @@ u8 calibrate_case(afl_state_t *afl, struct queue_entry *q, u8 *use_mem,
     if (afl->stop_soon || fault != afl->crash_mode) goto abort_calibration;
 
     if (!afl->dumb_mode && !afl->stage_cur &&
-        !count_bytes(afl->fsrv.trace_bits)) {
+        !count_bytes(afl, afl->fsrv.trace_bits)) {
 
       fault = FAULT_NOINST;
       goto abort_calibration;
 
     }
 
-    cksum = hash32(afl->fsrv.trace_bits, MAP_SIZE, HASH_CONST);
+    cksum = hash32(afl->fsrv.trace_bits, afl->fsrv.map_size, HASH_CONST);
 
     if (q->exec_cksum != cksum) {
 
@@ -370,23 +364,21 @@ u8 calibrate_case(afl_state_t *afl, struct queue_entry *q, u8 *use_mem,
 
         u32 i;
 
-        for (i = 0; i < MAP_SIZE; ++i) {
-
-          if (!afl->var_bytes[i] && first_trace[i] != afl->fsrv.trace_bits[i]) {
+        for (i = 0; i < afl->fsrv.map_size; ++i) {
 
+          if (unlikely(!afl->var_bytes[i]) &&
+              unlikely(afl->first_trace[i] != afl->fsrv.trace_bits[i]))
             afl->var_bytes[i] = 1;
-            afl->stage_max = CAL_CYCLES_LONG;
-
-          }
 
         }
 
         var_detected = 1;
+        afl->stage_max = CAL_CYCLES_LONG;
 
       } else {
 
         q->exec_cksum = cksum;
-        memcpy(first_trace, afl->fsrv.trace_bits, MAP_SIZE);
+        memcpy(afl->first_trace, afl->fsrv.trace_bits, afl->fsrv.map_size);
 
       }
 
@@ -403,7 +395,7 @@ u8 calibrate_case(afl_state_t *afl, struct queue_entry *q, u8 *use_mem,
      This is used for fuzzing air time calculations in calculate_score(). */
 
   q->exec_us = (stop_us - start_us) / afl->stage_max;
-  q->bitmap_size = count_bytes(afl->fsrv.trace_bits);
+  q->bitmap_size = count_bytes(afl, afl->fsrv.trace_bits);
   q->handicap = handicap;
   q->cal_failed = 0;
 
@@ -431,7 +423,7 @@ abort_calibration:
 
   if (var_detected) {
 
-    afl->var_byte_count = count_bytes(afl->var_bytes);
+    afl->var_byte_count = count_bytes(afl, afl->var_bytes);
 
     if (!q->var_behavior) {
 
@@ -471,8 +463,6 @@ void sync_fuzzers(afl_state_t *afl) {
 
   while ((sd_ent = readdir(sd))) {
 
-    static u8 stage_tmp[128];
-
     DIR *          qd;
     struct dirent *qd_ent;
     u8 *           qd_path, *qd_synced_path;
@@ -511,13 +501,14 @@ void sync_fuzzers(afl_state_t *afl) {
 
     /* Show stats */
 
-    sprintf(stage_tmp, "sync %u", ++sync_cnt);
-    afl->stage_name = stage_tmp;
+    snprintf(afl->stage_name_buf, STAGE_BUF_SIZE, "sync %u", ++sync_cnt);
+
+    afl->stage_name = afl->stage_name_buf;
     afl->stage_cur = 0;
     afl->stage_max = 0;
 
-    /* For every file queued by this fuzzer, parse ID and see if we have looked
-       at it before; exec a test case if not. */
+    /* For every file queued by this fuzzer, parse ID and see if we have
+       looked at it before; exec a test case if not. */
 
     while ((qd_ent = readdir(qd))) {
 
@@ -564,7 +555,7 @@ void sync_fuzzers(afl_state_t *afl) {
 
         write_to_testcase(afl, mem, st.st_size);
 
-        fault = run_target(afl, afl->fsrv.exec_tmout);
+        fault = run_target(afl, &afl->fsrv, afl->fsrv.exec_tmout);
 
         if (afl->stop_soon) goto close_sync;
 
@@ -608,26 +599,25 @@ u8 trim_case(afl_state_t *afl, struct queue_entry *q, u8 *in_buf) {
   if (afl->mutator && afl->mutator->afl_custom_trim)
     return trim_case_custom(afl, q, in_buf);
 
-  static u8 tmp[64];
-  static u8 clean_trace[MAP_SIZE];
-
   u8  needs_write = 0, fault = 0;
   u32 trim_exec = 0;
   u32 remove_len;
   u32 len_p2;
 
+  u8 val_bufs[2][STRINGIFY_VAL_SIZE_MAX];
+
   /* Although the trimmer will be less useful when variable behavior is
      detected, it will still work to some extent, so we don't check for
      this. */
 
   if (q->len < 5) return 0;
 
-  afl->stage_name = tmp;
+  afl->stage_name = afl->stage_name_buf;
   afl->bytes_trim_in += q->len;
 
   /* Select initial chunk len, starting with large steps. */
 
-  len_p2 = next_p2(q->len);
+  len_p2 = next_pow2(q->len);
 
   remove_len = MAX(len_p2 / TRIM_START_STEPS, TRIM_MIN_BYTES);
 
@@ -638,7 +628,9 @@ u8 trim_case(afl_state_t *afl, struct queue_entry *q, u8 *in_buf) {
 
     u32 remove_pos = remove_len;
 
-    sprintf(tmp, "trim %s/%s", DI(remove_len), DI(remove_len));
+    sprintf(afl->stage_name_buf, "trim %s/%s",
+            u_stringify_int(val_bufs[0], remove_len),
+            u_stringify_int(val_bufs[1], remove_len));
 
     afl->stage_cur = 0;
     afl->stage_max = q->len / remove_len;
@@ -650,14 +642,15 @@ u8 trim_case(afl_state_t *afl, struct queue_entry *q, u8 *in_buf) {
 
       write_with_gap(afl, in_buf, q->len, remove_pos, trim_avail);
 
-      fault = run_target(afl, afl->fsrv.exec_tmout);
+      fault = run_target(afl, &afl->fsrv, afl->fsrv.exec_tmout);
       ++afl->trim_execs;
 
       if (afl->stop_soon || fault == FAULT_ERROR) goto abort_trimming;
 
-      /* Note that we don't keep track of crashes or hangs here; maybe TODO? */
+      /* Note that we don't keep track of crashes or hangs here; maybe TODO?
+       */
 
-      cksum = hash32(afl->fsrv.trace_bits, MAP_SIZE, HASH_CONST);
+      cksum = hash32(afl->fsrv.trace_bits, afl->fsrv.map_size, HASH_CONST);
 
       /* If the deletion had no impact on the trace, make it permanent. This
          isn't perfect for variable-path inputs, but we're just making a
@@ -669,7 +662,7 @@ u8 trim_case(afl_state_t *afl, struct queue_entry *q, u8 *in_buf) {
         u32 move_tail = q->len - remove_pos - trim_avail;
 
         q->len -= trim_avail;
-        len_p2 = next_p2(q->len);
+        len_p2 = next_pow2(q->len);
 
         memmove(in_buf + remove_pos, in_buf + remove_pos + trim_avail,
                 move_tail);
@@ -680,7 +673,7 @@ u8 trim_case(afl_state_t *afl, struct queue_entry *q, u8 *in_buf) {
         if (!needs_write) {
 
           needs_write = 1;
-          memcpy(clean_trace, afl->fsrv.trace_bits, MAP_SIZE);
+          memcpy(afl->clean_trace, afl->fsrv.trace_bits, afl->fsrv.map_size);
 
         }
 
@@ -722,7 +715,7 @@ u8 trim_case(afl_state_t *afl, struct queue_entry *q, u8 *in_buf) {
     ck_write(fd, in_buf, q->len, q->fname);
     close(fd);
 
-    memcpy(afl->fsrv.trace_bits, clean_trace, MAP_SIZE);
+    memcpy(afl->fsrv.trace_bits, afl->clean_trace, afl->fsrv.map_size);
     update_bitmap_score(afl, q);
 
   }
@@ -744,14 +737,19 @@ u8 common_fuzz_stuff(afl_state_t *afl, u8 *out_buf, u32 len) {
 
   if (afl->post_handler) {
 
-    out_buf = afl->post_handler(out_buf, &len);
-    if (!out_buf || !len) return 0;
+    u8 *post_buf = NULL;
+
+    size_t post_len =
+        afl->post_handler(afl->post_data, out_buf, len, &post_buf);
+    if (!post_buf || !post_len) return 0;
+    out_buf = post_buf;
+    len = post_len;
 
   }
 
   write_to_testcase(afl, out_buf, len);
 
-  fault = run_target(afl, afl->fsrv.exec_tmout);
+  fault = run_target(afl, &afl->fsrv, afl->fsrv.exec_tmout);
 
   if (afl->stop_soon) return 1;
 
diff --git a/src/afl-fuzz-globals.c b/src/afl-fuzz-state.c
index efffa749..f58345fb 100644
--- a/src/afl-fuzz-globals.c
+++ b/src/afl-fuzz-state.c
@@ -30,10 +30,9 @@ s8  interesting_8[] = {INTERESTING_8};
 s16 interesting_16[] = {INTERESTING_8, INTERESTING_16};
 s32 interesting_32[] = {INTERESTING_8, INTERESTING_16, INTERESTING_32};
 
-char *power_names[POWER_SCHEDULES_NUM] = {"explore", "fast",    "coe",  "lin",
-                                          "quad",    "exploit", "mmopt"};
+char *power_names[POWER_SCHEDULES_NUM] = {
 
-u8 *doc_path = NULL;                    /* gath to documentation dir        */
+    "explore", "fast", "coe", "lin", "quad", "exploit", "mmopt", "rare"};
 
 /* Initialize MOpt "globals" for this afl state */
 
@@ -78,6 +77,10 @@ list_t afl_states = {.element_prealloc_count = 0};
 
 void afl_state_init(afl_state_t *afl) {
 
+  /* thanks to this memset, growing vars like out_buf
+  and out_size are NULL/0 by default. */
+  memset(afl, 0, sizeof(afl_state_t));
+
   afl->w_init = 0.9;
   afl->w_end = 0.3;
   afl->g_max = 5000;
@@ -96,6 +99,10 @@ void afl_state_init(afl_state_t *afl) {
 
   afl->fsrv.use_stdin = 1;
 
+  afl->fsrv.map_size = MAP_SIZE;
+  afl->fsrv.function_opt = (u8 *)afl;
+  afl->fsrv.function_ptr = &maybe_add_auto;
+
   afl->cal_cycles = CAL_CYCLES;
   afl->cal_cycles_long = CAL_CYCLES_LONG;
 
@@ -114,6 +121,29 @@ void afl_state_init(afl_state_t *afl) {
   afl->fsrv.child_pid = -1;
   afl->fsrv.out_dir_fd = -1;
 
+  afl->cmplog_prev_timed_out = 0;
+
+  /* statis file */
+  afl->last_bitmap_cvg = 0;
+  afl->last_stability = 0;
+  afl->last_eps = 0;
+
+  /* plot file saves from last run */
+  afl->plot_prev_qp = 0;
+  afl->plot_prev_pf = 0;
+  afl->plot_prev_pnf = 0;
+  afl->plot_prev_ce = 0;
+  afl->plot_prev_md = 0;
+  afl->plot_prev_qc = 0;
+  afl->plot_prev_uc = 0;
+  afl->plot_prev_uh = 0;
+
+  afl->stats_last_stats_ms = 0;
+  afl->stats_last_plot_ms = 0;
+  afl->stats_last_ms = 0;
+  afl->stats_last_execs = 0;
+  afl->stats_avg_exec = -1;
+
   init_mopt_globals(afl);
 
   list_append(&afl_states, afl);
@@ -254,6 +284,13 @@ void read_afl_environment(afl_state_t *afl, char **envp) {
             afl->afl_env.afl_autoresume =
                 get_afl_env(afl_environment_variables[i]) ? 1 : 0;
 
+          } else if (!strncmp(env, "AFL_CAL_FAST",
+
+                              afl_environment_variable_len)) {
+
+            afl->afl_env.afl_cal_fast =
+                get_afl_env(afl_environment_variables[i]) ? 1 : 0;
+
           } else if (!strncmp(env, "AFL_TMPDIR",
 
                               afl_environment_variable_len)) {
@@ -321,6 +358,17 @@ void read_afl_environment(afl_state_t *afl, char **envp) {
 
 void afl_state_deinit(afl_state_t *afl) {
 
+  if (afl->post_deinit) afl->post_deinit(afl->post_data);
+  if (afl->in_place_resume) ck_free(afl->in_dir);
+  if (afl->sync_id) ck_free(afl->out_dir);
+
+  free(afl->out_buf);
+  free(afl->out_scratch_buf);
+  free(afl->eff_buf);
+  free(afl->in_buf);
+  free(afl->in_scratch_buf);
+  free(afl->ex_buf);
+
   list_remove(&afl_states, afl);
 
 }
diff --git a/src/afl-fuzz-stats.c b/src/afl-fuzz-stats.c
index 63cca14d..2e680dbb 100644
--- a/src/afl-fuzz-stats.c
+++ b/src/afl-fuzz-stats.c
@@ -24,25 +24,27 @@
  */
 
 #include "afl-fuzz.h"
+#include <limits.h>
 
 /* Update stats file for unattended monitoring. */
 
 void write_stats_file(afl_state_t *afl, double bitmap_cvg, double stability,
                       double eps) {
 
-  static double        last_bcvg, last_stab, last_eps;
-  static struct rusage rus;
+  struct rusage rus;
 
-  u8 *  fn = alloc_printf("%s/fuzzer_stats", afl->out_dir);
-  s32   fd;
-  FILE *f;
+  unsigned long long int cur_time = get_cur_time();
+  u8                     fn[PATH_MAX];
+  s32                    fd;
+  FILE *                 f;
+  uint32_t               t_bytes = count_non_255_bytes(afl, afl->virgin_bits);
+
+  snprintf(fn, PATH_MAX, "%s/fuzzer_stats", afl->out_dir);
 
   fd = open(fn, O_WRONLY | O_CREAT | O_TRUNC, 0600);
 
   if (fd < 0) PFATAL("Unable to create '%s'", fn);
 
-  ck_free(fn);
-
   f = fdopen(fd, "w");
 
   if (!f) PFATAL("fdopen() failed");
@@ -52,15 +54,15 @@ void write_stats_file(afl_state_t *afl, double bitmap_cvg, double stability,
 
   if (!bitmap_cvg && !stability && !eps) {
 
-    bitmap_cvg = last_bcvg;
-    stability = last_stab;
-    eps = last_eps;
+    bitmap_cvg = afl->last_bitmap_cvg;
+    stability = afl->last_stability;
+    eps = afl->last_eps;
 
   } else {
 
-    last_bcvg = bitmap_cvg;
-    last_stab = stability;
-    last_eps = eps;
+    afl->last_bitmap_cvg = bitmap_cvg;
+    afl->last_stability = stability;
+    afl->last_eps = eps;
 
   }
 
@@ -70,8 +72,10 @@ void write_stats_file(afl_state_t *afl, double bitmap_cvg, double stability,
       f,
       "start_time        : %llu\n"
       "last_update       : %llu\n"
+      "run_time          : %llu\n"
       "fuzzer_pid        : %d\n"
       "cycles_done       : %llu\n"
+      "cycles_wo_finds   : %llu\n"
       "execs_done        : %llu\n"
       "execs_per_sec     : %0.02f\n"
       //          "real_execs_per_sec: %0.02f\n"  // damn the name is too long
@@ -93,17 +97,20 @@ void write_stats_file(afl_state_t *afl, double bitmap_cvg, double stability,
       "last_hang         : %llu\n"
       "execs_since_crash : %llu\n"
       "exec_timeout      : %u\n"
-      "slowest_exec_ms   : %llu\n"
+      "slowest_exec_ms   : %u\n"
       "peak_rss_mb       : %lu\n"
+      "edges_found       : %u\n"
+      "var_byte_count    : %u\n"
       "afl_banner        : %s\n"
       "afl_version       : " VERSION
       "\n"
       "target_mode       : %s%s%s%s%s%s%s%s\n"
       "command_line      : %s\n",
-      afl->start_time / 1000, get_cur_time() / 1000, getpid(),
-      afl->queue_cycle ? (afl->queue_cycle - 1) : 0, afl->total_execs,
-      /*eps,*/ afl->total_execs /
-          ((double)(get_cur_time() - afl->start_time) / 1000),
+      afl->start_time / 1000, cur_time / 1000,
+      (cur_time - afl->start_time) / 1000, getpid(),
+      afl->queue_cycle ? (afl->queue_cycle - 1) : 0, afl->cycles_wo_finds,
+      afl->total_execs,
+      afl->total_execs / ((double)(get_cur_time() - afl->start_time) / 1000),
       afl->queued_paths, afl->queued_favored, afl->queued_discovered,
       afl->queued_imported, afl->max_depth, afl->current_entry,
       afl->pending_favored, afl->pending_not_fuzzed, afl->queued_variable,
@@ -116,12 +123,13 @@ void write_stats_file(afl_state_t *afl, double bitmap_cvg, double stability,
 #else
       (unsigned long int)(rus.ru_maxrss >> 10),
 #endif
-      afl->use_banner, afl->unicorn_mode ? "unicorn" : "",
-      afl->qemu_mode ? "qemu " : "", afl->dumb_mode ? " dumb " : "",
-      afl->no_forkserver ? "no_fsrv " : "", afl->crash_mode ? "crash " : "",
+      t_bytes, afl->var_byte_count, afl->use_banner,
+      afl->unicorn_mode ? "unicorn" : "", afl->fsrv.qemu_mode ? "qemu " : "",
+      afl->dumb_mode ? " dumb " : "", afl->no_forkserver ? "no_fsrv " : "",
+      afl->crash_mode ? "crash " : "",
       afl->persistent_mode ? "persistent " : "",
       afl->deferred_mode ? "deferred " : "",
-      (afl->unicorn_mode || afl->qemu_mode || afl->dumb_mode ||
+      (afl->unicorn_mode || afl->fsrv.qemu_mode || afl->dumb_mode ||
        afl->no_forkserver || afl->crash_mode || afl->persistent_mode ||
        afl->deferred_mode)
           ? ""
@@ -137,23 +145,24 @@ void write_stats_file(afl_state_t *afl, double bitmap_cvg, double stability,
 
 void maybe_update_plot_file(afl_state_t *afl, double bitmap_cvg, double eps) {
 
-  static u32 prev_qp, prev_pf, prev_pnf, prev_ce, prev_md;
-  static u64 prev_qc, prev_uc, prev_uh;
-
-  if (prev_qp == afl->queued_paths && prev_pf == afl->pending_favored &&
-      prev_pnf == afl->pending_not_fuzzed && prev_ce == afl->current_entry &&
-      prev_qc == afl->queue_cycle && prev_uc == afl->unique_crashes &&
-      prev_uh == afl->unique_hangs && prev_md == afl->max_depth)
+  if (afl->plot_prev_qp == afl->queued_paths &&
+      afl->plot_prev_pf == afl->pending_favored &&
+      afl->plot_prev_pnf == afl->pending_not_fuzzed &&
+      afl->plot_prev_ce == afl->current_entry &&
+      afl->plot_prev_qc == afl->queue_cycle &&
+      afl->plot_prev_uc == afl->unique_crashes &&
+      afl->plot_prev_uh == afl->unique_hangs &&
+      afl->plot_prev_md == afl->max_depth)
     return;
 
-  prev_qp = afl->queued_paths;
-  prev_pf = afl->pending_favored;
-  prev_pnf = afl->pending_not_fuzzed;
-  prev_ce = afl->current_entry;
-  prev_qc = afl->queue_cycle;
-  prev_uc = afl->unique_crashes;
-  prev_uh = afl->unique_hangs;
-  prev_md = afl->max_depth;
+  afl->plot_prev_qp = afl->queued_paths;
+  afl->plot_prev_pf = afl->pending_favored;
+  afl->plot_prev_pnf = afl->pending_not_fuzzed;
+  afl->plot_prev_ce = afl->current_entry;
+  afl->plot_prev_qc = afl->queue_cycle;
+  afl->plot_prev_uc = afl->unique_crashes;
+  afl->plot_prev_uh = afl->unique_hangs;
+  afl->plot_prev_md = afl->max_depth;
 
   /* Fields in the file:
 
@@ -192,21 +201,47 @@ static void check_term_size(afl_state_t *afl) {
 
 void show_stats(afl_state_t *afl) {
 
-  static u64    last_stats_ms, last_plot_ms, last_ms, last_execs;
-  static double avg_exec;
-  double        t_byte_ratio, stab_ratio;
+  double t_byte_ratio, stab_ratio;
 
   u64 cur_ms;
   u32 t_bytes, t_bits;
 
   u32 banner_len, banner_pad;
   u8  tmp[256];
+  u8  time_tmp[64];
+
+  u8 val_buf[8][STRINGIFY_VAL_SIZE_MAX];
+#define IB(i) (val_buf[(i)])
 
   cur_ms = get_cur_time();
 
+  if (afl->most_time_key) {
+
+    if (afl->most_time * 1000 < cur_ms - afl->start_time) {
+
+      afl->most_time_key = 2;
+      afl->stop_soon = 2;
+
+    }
+
+  }
+
+  if (afl->most_execs_key == 1) {
+
+    if (afl->most_execs <= afl->total_execs) {
+
+      afl->most_execs_key = 2;
+      afl->stop_soon = 2;
+
+    }
+
+  }
+
   /* If not enough time has passed since last UI update, bail out. */
 
-  if (cur_ms - last_ms < 1000 / UI_TARGET_HZ && !afl->force_ui_update) return;
+  if (cur_ms - afl->stats_last_ms < 1000 / UI_TARGET_HZ &&
+      !afl->force_ui_update)
+    return;
 
   /* Check if we're past the 10 minute mark. */
 
@@ -214,49 +249,51 @@ void show_stats(afl_state_t *afl) {
 
   /* Calculate smoothed exec speed stats. */
 
-  if (!last_execs) {
+  if (!afl->stats_last_execs) {
 
-    avg_exec = ((double)afl->total_execs) * 1000 / (cur_ms - afl->start_time);
+    afl->stats_avg_exec =
+        ((double)afl->total_execs) * 1000 / (cur_ms - afl->start_time);
 
   } else {
 
-    double cur_avg =
-        ((double)(afl->total_execs - last_execs)) * 1000 / (cur_ms - last_ms);
+    double cur_avg = ((double)(afl->total_execs - afl->stats_last_execs)) *
+                     1000 / (cur_ms - afl->stats_last_ms);
 
     /* If there is a dramatic (5x+) jump in speed, reset the indicator
        more quickly. */
 
-    if (cur_avg * 5 < avg_exec || cur_avg / 5 > avg_exec) avg_exec = cur_avg;
+    if (cur_avg * 5 < afl->stats_avg_exec || cur_avg / 5 > afl->stats_avg_exec)
+      afl->stats_avg_exec = cur_avg;
 
-    avg_exec = avg_exec * (1.0 - 1.0 / AVG_SMOOTHING) +
-               cur_avg * (1.0 / AVG_SMOOTHING);
+    afl->stats_avg_exec = afl->stats_avg_exec * (1.0 - 1.0 / AVG_SMOOTHING) +
+                          cur_avg * (1.0 / AVG_SMOOTHING);
 
   }
 
-  last_ms = cur_ms;
-  last_execs = afl->total_execs;
+  afl->stats_last_ms = cur_ms;
+  afl->stats_last_execs = afl->total_execs;
 
   /* Tell the callers when to contact us (as measured in execs). */
 
-  afl->stats_update_freq = avg_exec / (UI_TARGET_HZ * 10);
+  afl->stats_update_freq = afl->stats_avg_exec / (UI_TARGET_HZ * 10);
   if (!afl->stats_update_freq) afl->stats_update_freq = 1;
 
   /* Do some bitmap stats. */
 
-  t_bytes = count_non_255_bytes(afl->virgin_bits);
-  t_byte_ratio = ((double)t_bytes * 100) / MAP_SIZE;
+  t_bytes = count_non_255_bytes(afl, afl->virgin_bits);
+  t_byte_ratio = ((double)t_bytes * 100) / afl->fsrv.map_size;
 
-  if (t_bytes)
-    stab_ratio = 100 - ((double)afl->var_byte_count) * 100 / t_bytes;
+  if (likely(t_bytes) && unlikely(afl->var_byte_count))
+    stab_ratio = 100 - (((double)afl->var_byte_count * 100) / t_bytes);
   else
     stab_ratio = 100;
 
   /* Roughly every minute, update fuzzer stats and save auto tokens. */
 
-  if (cur_ms - last_stats_ms > STATS_UPDATE_SEC * 1000) {
+  if (cur_ms - afl->stats_last_stats_ms > STATS_UPDATE_SEC * 1000) {
 
-    last_stats_ms = cur_ms;
-    write_stats_file(afl, t_byte_ratio, stab_ratio, avg_exec);
+    afl->stats_last_stats_ms = cur_ms;
+    write_stats_file(afl, t_byte_ratio, stab_ratio, afl->stats_avg_exec);
     save_auto(afl);
     write_bitmap(afl);
 
@@ -264,10 +301,10 @@ void show_stats(afl_state_t *afl) {
 
   /* Every now and then, write plot data. */
 
-  if (cur_ms - last_plot_ms > PLOT_UPDATE_SEC * 1000) {
+  if (cur_ms - afl->stats_last_plot_ms > PLOT_UPDATE_SEC * 1000) {
 
-    last_plot_ms = cur_ms;
-    maybe_update_plot_file(afl, t_byte_ratio, avg_exec);
+    afl->stats_last_plot_ms = cur_ms;
+    maybe_update_plot_file(afl, t_byte_ratio, afl->stats_avg_exec);
 
   }
 
@@ -290,7 +327,7 @@ void show_stats(afl_state_t *afl) {
 
   /* Compute some mildly useful bitmap stats. */
 
-  t_bits = (MAP_SIZE << 3) - count_bits(afl->virgin_bits);
+  t_bits = (afl->fsrv.map_size << 3) - count_bits(afl, afl->virgin_bits);
 
   /* Now, for the visuals... */
 
@@ -384,9 +421,10 @@ void show_stats(afl_state_t *afl) {
 
   }
 
+  u_stringify_time_diff(time_tmp, cur_ms, afl->start_time);
   SAYF(bV bSTOP "        run time : " cRST "%-33s " bSTG bV bSTOP
                 "  cycles done : %s%-5s " bSTG              bV "\n",
-       DTD(cur_ms, afl->start_time), tmp, DI(afl->queue_cycle - 1));
+       time_tmp, tmp, u_stringify_int(IB(0), afl->queue_cycle - 1));
 
   /* We want to warn people about not seeing new paths after a full cycle,
      except when resuming fuzzing or running in non-instrumented mode. */
@@ -395,8 +433,8 @@ void show_stats(afl_state_t *afl) {
       (afl->last_path_time || afl->resuming_fuzz || afl->queue_cycle == 1 ||
        afl->in_bitmap || afl->crash_mode)) {
 
-    SAYF(bV bSTOP "   last new path : " cRST "%-33s ",
-         DTD(cur_ms, afl->last_path_time));
+    u_stringify_time_diff(time_tmp, cur_ms, afl->last_path_time);
+    SAYF(bV bSTOP "   last new path : " cRST "%-33s ", time_tmp);
 
   } else {
 
@@ -413,25 +451,26 @@ void show_stats(afl_state_t *afl) {
   }
 
   SAYF(bSTG bV bSTOP "  total paths : " cRST "%-5s " bSTG bV "\n",
-       DI(afl->queued_paths));
+       u_stringify_int(IB(0), afl->queued_paths));
 
   /* Highlight crashes in red if found, denote going over the KEEP_UNIQUE_CRASH
      limit with a '+' appended to the count. */
 
-  sprintf(tmp, "%s%s", DI(afl->unique_crashes),
+  sprintf(tmp, "%s%s", u_stringify_int(IB(0), afl->unique_crashes),
           (afl->unique_crashes >= KEEP_UNIQUE_CRASH) ? "+" : "");
 
+  u_stringify_time_diff(time_tmp, cur_ms, afl->last_crash_time);
   SAYF(bV bSTOP " last uniq crash : " cRST "%-33s " bSTG bV bSTOP
                 " uniq crashes : %s%-6s" bSTG               bV "\n",
-       DTD(cur_ms, afl->last_crash_time), afl->unique_crashes ? cLRD : cRST,
-       tmp);
+       time_tmp, afl->unique_crashes ? cLRD : cRST, tmp);
 
-  sprintf(tmp, "%s%s", DI(afl->unique_hangs),
+  sprintf(tmp, "%s%s", u_stringify_int(IB(0), afl->unique_hangs),
           (afl->unique_hangs >= KEEP_UNIQUE_HANG) ? "+" : "");
 
+  u_stringify_time_diff(time_tmp, cur_ms, afl->last_hang_time);
   SAYF(bV bSTOP "  last uniq hang : " cRST "%-33s " bSTG bV bSTOP
                 "   uniq hangs : " cRST "%-6s" bSTG         bV "\n",
-       DTD(cur_ms, afl->last_hang_time), tmp);
+       time_tmp, tmp);
 
   SAYF(bVR bH bSTOP            cCYA
        " cycle progress " bSTG bH10 bH5 bH2 bH2 bHB bH bSTOP cCYA
@@ -441,21 +480,22 @@ void show_stats(afl_state_t *afl) {
      together, but then cram them into a fixed-width field - so we need to
      put them in a temporary buffer first. */
 
-  sprintf(tmp, "%s%s%u (%0.01f%%)", DI(afl->current_entry),
+  sprintf(tmp, "%s%s%u (%0.01f%%)", u_stringify_int(IB(0), afl->current_entry),
           afl->queue_cur->favored ? "." : "*", afl->queue_cur->fuzz_level,
           ((double)afl->current_entry * 100) / afl->queued_paths);
 
   SAYF(bV bSTOP "  now processing : " cRST "%-16s " bSTG bV bSTOP, tmp);
 
   sprintf(tmp, "%0.02f%% / %0.02f%%",
-          ((double)afl->queue_cur->bitmap_size) * 100 / MAP_SIZE, t_byte_ratio);
+          ((double)afl->queue_cur->bitmap_size) * 100 / afl->fsrv.map_size,
+          t_byte_ratio);
 
   SAYF("    map density : %s%-21s" bSTG bV "\n",
        t_byte_ratio > 70 ? cLRD
                          : ((t_bytes < 200 && !afl->dumb_mode) ? cPIN : cRST),
        tmp);
 
-  sprintf(tmp, "%s (%0.02f%%)", DI(afl->cur_skipped_paths),
+  sprintf(tmp, "%s (%0.02f%%)", u_stringify_int(IB(0), afl->cur_skipped_paths),
           ((double)afl->cur_skipped_paths * 100) / afl->queued_paths);
 
   SAYF(bV bSTOP " paths timed out : " cRST "%-16s " bSTG bV, tmp);
@@ -468,7 +508,7 @@ void show_stats(afl_state_t *afl) {
        " stage progress " bSTG bH10 bH5 bH2 bH2 bX bH bSTOP cCYA
        " findings in depth " bSTG bH10 bH5 bH2 bH2 bVL "\n");
 
-  sprintf(tmp, "%s (%0.02f%%)", DI(afl->queued_favored),
+  sprintf(tmp, "%s (%0.02f%%)", u_stringify_int(IB(0), afl->queued_favored),
           ((double)afl->queued_favored) * 100 / afl->queued_paths);
 
   /* Yeah... it's still going on... halp? */
@@ -479,58 +519,61 @@ void show_stats(afl_state_t *afl) {
 
   if (!afl->stage_max) {
 
-    sprintf(tmp, "%s/-", DI(afl->stage_cur));
+    sprintf(tmp, "%s/-", u_stringify_int(IB(0), afl->stage_cur));
 
   } else {
 
-    sprintf(tmp, "%s/%s (%0.02f%%)", DI(afl->stage_cur), DI(afl->stage_max),
+    sprintf(tmp, "%s/%s (%0.02f%%)", u_stringify_int(IB(0), afl->stage_cur),
+            u_stringify_int(IB(1), afl->stage_max),
             ((double)afl->stage_cur) * 100 / afl->stage_max);
 
   }
 
   SAYF(bV bSTOP " stage execs : " cRST "%-21s" bSTG bV bSTOP, tmp);
 
-  sprintf(tmp, "%s (%0.02f%%)", DI(afl->queued_with_cov),
+  sprintf(tmp, "%s (%0.02f%%)", u_stringify_int(IB(0), afl->queued_with_cov),
           ((double)afl->queued_with_cov) * 100 / afl->queued_paths);
 
   SAYF("  new edges on : " cRST "%-22s" bSTG bV "\n", tmp);
 
-  sprintf(tmp, "%s (%s%s unique)", DI(afl->total_crashes),
-          DI(afl->unique_crashes),
+  sprintf(tmp, "%s (%s%s unique)", u_stringify_int(IB(0), afl->total_crashes),
+          u_stringify_int(IB(1), afl->unique_crashes),
           (afl->unique_crashes >= KEEP_UNIQUE_CRASH) ? "+" : "");
 
   if (afl->crash_mode) {
 
     SAYF(bV bSTOP " total execs : " cRST "%-20s " bSTG bV bSTOP
                   "   new crashes : %s%-22s" bSTG         bV "\n",
-         DI(afl->total_execs), afl->unique_crashes ? cLRD : cRST, tmp);
+         u_stringify_int(IB(0), afl->total_execs),
+         afl->unique_crashes ? cLRD : cRST, tmp);
 
   } else {
 
     SAYF(bV bSTOP " total execs : " cRST "%-20s " bSTG bV bSTOP
                   " total crashes : %s%-22s" bSTG         bV "\n",
-         DI(afl->total_execs), afl->unique_crashes ? cLRD : cRST, tmp);
+         u_stringify_int(IB(0), afl->total_execs),
+         afl->unique_crashes ? cLRD : cRST, tmp);
 
   }
 
   /* Show a warning about slow execution. */
 
-  if (avg_exec < 100) {
+  if (afl->stats_avg_exec < 100) {
 
-    sprintf(tmp, "%s/sec (%s)", DF(avg_exec),
-            avg_exec < 20 ? "zzzz..." : "slow!");
+    sprintf(tmp, "%s/sec (%s)", u_stringify_float(IB(0), afl->stats_avg_exec),
+            afl->stats_avg_exec < 20 ? "zzzz..." : "slow!");
 
     SAYF(bV bSTOP "  exec speed : " cLRD "%-20s ", tmp);
 
   } else {
 
-    sprintf(tmp, "%s/sec", DF(avg_exec));
+    sprintf(tmp, "%s/sec", u_stringify_float(IB(0), afl->stats_avg_exec));
     SAYF(bV bSTOP "  exec speed : " cRST "%-20s ", tmp);
 
   }
 
-  sprintf(tmp, "%s (%s%s unique)", DI(afl->total_tmouts),
-          DI(afl->unique_tmouts),
+  sprintf(tmp, "%s (%s%s unique)", u_stringify_int(IB(0), afl->total_tmouts),
+          u_stringify_int(IB(1), afl->unique_tmouts),
           (afl->unique_hangs >= KEEP_UNIQUE_HANG) ? "+" : "");
 
   SAYF(bSTG bV bSTOP "  total tmouts : " cRST "%-22s" bSTG bV "\n", tmp);
@@ -547,70 +590,81 @@ void show_stats(afl_state_t *afl) {
 
   } else {
 
-    sprintf(
-        tmp, "%s/%s, %s/%s, %s/%s", DI(afl->stage_finds[STAGE_FLIP1]),
-        DI(afl->stage_cycles[STAGE_FLIP1]), DI(afl->stage_finds[STAGE_FLIP2]),
-        DI(afl->stage_cycles[STAGE_FLIP2]), DI(afl->stage_finds[STAGE_FLIP4]),
-        DI(afl->stage_cycles[STAGE_FLIP4]));
+    sprintf(tmp, "%s/%s, %s/%s, %s/%s",
+            u_stringify_int(IB(0), afl->stage_finds[STAGE_FLIP1]),
+            u_stringify_int(IB(1), afl->stage_cycles[STAGE_FLIP1]),
+            u_stringify_int(IB(2), afl->stage_finds[STAGE_FLIP2]),
+            u_stringify_int(IB(3), afl->stage_cycles[STAGE_FLIP2]),
+            u_stringify_int(IB(4), afl->stage_finds[STAGE_FLIP4]),
+            u_stringify_int(IB(5), afl->stage_cycles[STAGE_FLIP4]));
 
   }
 
   SAYF(bV bSTOP "   bit flips : " cRST "%-36s " bSTG bV bSTOP
                 "    levels : " cRST "%-10s" bSTG       bV "\n",
-       tmp, DI(afl->max_depth));
+       tmp, u_stringify_int(IB(0), afl->max_depth));
 
   if (!afl->skip_deterministic)
-    sprintf(
-        tmp, "%s/%s, %s/%s, %s/%s", DI(afl->stage_finds[STAGE_FLIP8]),
-        DI(afl->stage_cycles[STAGE_FLIP8]), DI(afl->stage_finds[STAGE_FLIP16]),
-        DI(afl->stage_cycles[STAGE_FLIP16]), DI(afl->stage_finds[STAGE_FLIP32]),
-        DI(afl->stage_cycles[STAGE_FLIP32]));
+    sprintf(tmp, "%s/%s, %s/%s, %s/%s",
+            u_stringify_int(IB(0), afl->stage_finds[STAGE_FLIP8]),
+            u_stringify_int(IB(1), afl->stage_cycles[STAGE_FLIP8]),
+            u_stringify_int(IB(2), afl->stage_finds[STAGE_FLIP16]),
+            u_stringify_int(IB(3), afl->stage_cycles[STAGE_FLIP16]),
+            u_stringify_int(IB(4), afl->stage_finds[STAGE_FLIP32]),
+            u_stringify_int(IB(5), afl->stage_cycles[STAGE_FLIP32]));
 
   SAYF(bV bSTOP "  byte flips : " cRST "%-36s " bSTG bV bSTOP
                 "   pending : " cRST "%-10s" bSTG       bV "\n",
-       tmp, DI(afl->pending_not_fuzzed));
+       tmp, u_stringify_int(IB(0), afl->pending_not_fuzzed));
 
   if (!afl->skip_deterministic)
-    sprintf(tmp, "%s/%s, %s/%s, %s/%s", DI(afl->stage_finds[STAGE_ARITH8]),
-            DI(afl->stage_cycles[STAGE_ARITH8]),
-            DI(afl->stage_finds[STAGE_ARITH16]),
-            DI(afl->stage_cycles[STAGE_ARITH16]),
-            DI(afl->stage_finds[STAGE_ARITH32]),
-            DI(afl->stage_cycles[STAGE_ARITH32]));
+    sprintf(tmp, "%s/%s, %s/%s, %s/%s",
+            u_stringify_int(IB(0), afl->stage_finds[STAGE_ARITH8]),
+            u_stringify_int(IB(1), afl->stage_cycles[STAGE_ARITH8]),
+            u_stringify_int(IB(2), afl->stage_finds[STAGE_ARITH16]),
+            u_stringify_int(IB(3), afl->stage_cycles[STAGE_ARITH16]),
+            u_stringify_int(IB(4), afl->stage_finds[STAGE_ARITH32]),
+            u_stringify_int(IB(5), afl->stage_cycles[STAGE_ARITH32]));
 
   SAYF(bV bSTOP " arithmetics : " cRST "%-36s " bSTG bV bSTOP
                 "  pend fav : " cRST "%-10s" bSTG       bV "\n",
-       tmp, DI(afl->pending_favored));
+       tmp, u_stringify_int(IB(0), afl->pending_favored));
 
   if (!afl->skip_deterministic)
-    sprintf(tmp, "%s/%s, %s/%s, %s/%s", DI(afl->stage_finds[STAGE_INTEREST8]),
-            DI(afl->stage_cycles[STAGE_INTEREST8]),
-            DI(afl->stage_finds[STAGE_INTEREST16]),
-            DI(afl->stage_cycles[STAGE_INTEREST16]),
-            DI(afl->stage_finds[STAGE_INTEREST32]),
-            DI(afl->stage_cycles[STAGE_INTEREST32]));
+    sprintf(tmp, "%s/%s, %s/%s, %s/%s",
+            u_stringify_int(IB(0), afl->stage_finds[STAGE_INTEREST8]),
+            u_stringify_int(IB(1), afl->stage_cycles[STAGE_INTEREST8]),
+            u_stringify_int(IB(2), afl->stage_finds[STAGE_INTEREST16]),
+            u_stringify_int(IB(3), afl->stage_cycles[STAGE_INTEREST16]),
+            u_stringify_int(IB(4), afl->stage_finds[STAGE_INTEREST32]),
+            u_stringify_int(IB(5), afl->stage_cycles[STAGE_INTEREST32]));
 
   SAYF(bV bSTOP "  known ints : " cRST "%-36s " bSTG bV bSTOP
                 " own finds : " cRST "%-10s" bSTG       bV "\n",
-       tmp, DI(afl->queued_discovered));
+       tmp, u_stringify_int(IB(0), afl->queued_discovered));
 
   if (!afl->skip_deterministic)
-    sprintf(tmp, "%s/%s, %s/%s, %s/%s", DI(afl->stage_finds[STAGE_EXTRAS_UO]),
-            DI(afl->stage_cycles[STAGE_EXTRAS_UO]),
-            DI(afl->stage_finds[STAGE_EXTRAS_UI]),
-            DI(afl->stage_cycles[STAGE_EXTRAS_UI]),
-            DI(afl->stage_finds[STAGE_EXTRAS_AO]),
-            DI(afl->stage_cycles[STAGE_EXTRAS_AO]));
+    sprintf(tmp, "%s/%s, %s/%s, %s/%s",
+            u_stringify_int(IB(0), afl->stage_finds[STAGE_EXTRAS_UO]),
+            u_stringify_int(IB(1), afl->stage_cycles[STAGE_EXTRAS_UO]),
+            u_stringify_int(IB(2), afl->stage_finds[STAGE_EXTRAS_UI]),
+            u_stringify_int(IB(3), afl->stage_cycles[STAGE_EXTRAS_UI]),
+            u_stringify_int(IB(4), afl->stage_finds[STAGE_EXTRAS_AO]),
+            u_stringify_int(IB(5), afl->stage_cycles[STAGE_EXTRAS_AO]));
 
   SAYF(bV bSTOP "  dictionary : " cRST "%-36s " bSTG bV bSTOP
                 "  imported : " cRST "%-10s" bSTG       bV "\n",
-       tmp, afl->sync_id ? DI(afl->queued_imported) : (u8 *)"n/a");
-
-  sprintf(
-      tmp, "%s/%s, %s/%s, %s/%s", DI(afl->stage_finds[STAGE_HAVOC]),
-      DI(afl->stage_cycles[STAGE_HAVOC]), DI(afl->stage_finds[STAGE_SPLICE]),
-      DI(afl->stage_cycles[STAGE_SPLICE]), DI(afl->stage_finds[STAGE_RADAMSA]),
-      DI(afl->stage_cycles[STAGE_RADAMSA]));
+       tmp,
+       afl->sync_id ? u_stringify_int(IB(0), afl->queued_imported)
+                    : (u8 *)"n/a");
+
+  sprintf(tmp, "%s/%s, %s/%s, %s/%s",
+          u_stringify_int(IB(0), afl->stage_finds[STAGE_HAVOC]),
+          u_stringify_int(IB(2), afl->stage_cycles[STAGE_HAVOC]),
+          u_stringify_int(IB(3), afl->stage_finds[STAGE_SPLICE]),
+          u_stringify_int(IB(4), afl->stage_cycles[STAGE_SPLICE]),
+          u_stringify_int(IB(5), afl->stage_finds[STAGE_RADAMSA]),
+          u_stringify_int(IB(6), afl->stage_cycles[STAGE_RADAMSA]));
 
   SAYF(bV bSTOP "   havoc/rad : " cRST "%-36s " bSTG bV bSTOP, tmp);
 
@@ -631,23 +685,25 @@ void show_stats(afl_state_t *afl) {
   if (afl->shm.cmplog_mode) {
 
     sprintf(tmp, "%s/%s, %s/%s, %s/%s, %s/%s",
-            DI(afl->stage_finds[STAGE_PYTHON]),
-            DI(afl->stage_cycles[STAGE_PYTHON]),
-            DI(afl->stage_finds[STAGE_CUSTOM_MUTATOR]),
-            DI(afl->stage_cycles[STAGE_CUSTOM_MUTATOR]),
-            DI(afl->stage_finds[STAGE_COLORIZATION]),
-            DI(afl->stage_cycles[STAGE_COLORIZATION]),
-            DI(afl->stage_finds[STAGE_ITS]), DI(afl->stage_cycles[STAGE_ITS]));
+            u_stringify_int(IB(0), afl->stage_finds[STAGE_PYTHON]),
+            u_stringify_int(IB(1), afl->stage_cycles[STAGE_PYTHON]),
+            u_stringify_int(IB(2), afl->stage_finds[STAGE_CUSTOM_MUTATOR]),
+            u_stringify_int(IB(3), afl->stage_cycles[STAGE_CUSTOM_MUTATOR]),
+            u_stringify_int(IB(4), afl->stage_finds[STAGE_COLORIZATION]),
+            u_stringify_int(IB(5), afl->stage_cycles[STAGE_COLORIZATION]),
+            u_stringify_int(IB(6), afl->stage_finds[STAGE_ITS]),
+            u_stringify_int(IB(7), afl->stage_cycles[STAGE_ITS]));
 
     SAYF(bV bSTOP "   custom/rq : " cRST "%-36s " bSTG bVR bH20 bH2 bH bRB "\n",
          tmp);
 
   } else {
 
-    sprintf(tmp, "%s/%s, %s/%s", DI(afl->stage_finds[STAGE_PYTHON]),
-            DI(afl->stage_cycles[STAGE_PYTHON]),
-            DI(afl->stage_finds[STAGE_CUSTOM_MUTATOR]),
-            DI(afl->stage_cycles[STAGE_CUSTOM_MUTATOR]));
+    sprintf(tmp, "%s/%s, %s/%s",
+            u_stringify_int(IB(0), afl->stage_finds[STAGE_PYTHON]),
+            u_stringify_int(IB(1), afl->stage_cycles[STAGE_PYTHON]),
+            u_stringify_int(IB(2), afl->stage_finds[STAGE_CUSTOM_MUTATOR]),
+            u_stringify_int(IB(3), afl->stage_cycles[STAGE_CUSTOM_MUTATOR]));
 
     SAYF(bV bSTOP "   py/custom : " cRST "%-36s " bSTG bVR bH20 bH2 bH bRB "\n",
          tmp);
@@ -663,7 +719,7 @@ void show_stats(afl_state_t *afl) {
     sprintf(tmp, "%0.02f%%/%s, ",
             ((double)(afl->bytes_trim_in - afl->bytes_trim_out)) * 100 /
                 afl->bytes_trim_in,
-            DI(afl->trim_execs));
+            u_stringify_int(IB(0), afl->trim_execs));
 
   }
 
@@ -688,8 +744,9 @@ void show_stats(afl_state_t *afl) {
 
   if (afl->mutator) {
 
-    sprintf(tmp, "%s/%s", DI(afl->stage_finds[STAGE_CUSTOM_MUTATOR]),
-            DI(afl->stage_cycles[STAGE_CUSTOM_MUTATOR]));
+    sprintf(tmp, "%s/%s",
+            u_stringify_int(IB(0), afl->stage_finds[STAGE_CUSTOM_MUTATOR]),
+            u_stringify_int(IB(1), afl->stage_cycles[STAGE_CUSTOM_MUTATOR]));
     SAYF(bV bSTOP " custom mut. : " cRST "%-36s " bSTG bV RESET_G1, tmp);
 
   } else {
@@ -702,6 +759,8 @@ void show_stats(afl_state_t *afl) {
 
   if (afl->cpu_core_count) {
 
+    char *spacing = SP10, snap[24] = " " cLGN "snapshot" cRST " ";
+
     double cur_runnable = get_runnable_processes();
     u32    cur_utilization = cur_runnable * 100 / afl->cpu_core_count;
 
@@ -716,23 +775,25 @@ void show_stats(afl_state_t *afl) {
 
     if (!afl->no_cpu_meter_red && cur_utilization >= 150) cpu_color = cLRD;
 
+    if (afl->fsrv.snapshot) spacing = snap;
+
 #ifdef HAVE_AFFINITY
 
     if (afl->cpu_aff >= 0) {
 
-      SAYF(SP10 cGRA "[cpu%03u:%s%3u%%" cGRA "]\r" cRST, MIN(afl->cpu_aff, 999),
-           cpu_color, MIN(cur_utilization, 999));
+      SAYF("%s" cGRA "[cpu%03u:%s%3u%%" cGRA "]\r" cRST, spacing,
+           MIN(afl->cpu_aff, 999), cpu_color, MIN(cur_utilization, 999));
 
     } else {
 
-      SAYF(SP10 cGRA "   [cpu:%s%3u%%" cGRA "]\r" cRST, cpu_color,
+      SAYF("%s" cGRA "   [cpu:%s%3u%%" cGRA "]\r" cRST, spacing, cpu_color,
            MIN(cur_utilization, 999));
 
     }
 
 #else
 
-    SAYF(SP10 cGRA "   [cpu:%s%3u%%" cGRA "]\r" cRST, cpu_color,
+    SAYF("%s" cGRA "   [cpu:%s%3u%%" cGRA "]\r" cRST, spacing, cpu_color,
          MIN(cur_utilization, 999));
 
 #endif                                                    /* ^HAVE_AFFINITY */
@@ -744,6 +805,8 @@ void show_stats(afl_state_t *afl) {
   /* Last line */
   SAYF(SET_G1 "\n" bSTG bLB bH30 bH20 bH2 bRB bSTOP cRST RESET_G1);
 
+#undef IB
+
   /* Hallelujah! */
 
   fflush(0);
@@ -762,6 +825,9 @@ void show_init_stats(afl_state_t *afl) {
   u64                 avg_us = 0;
   u32                 max_len = 0;
 
+  u8 val_bufs[4][STRINGIFY_VAL_SIZE_MAX];
+#define IB(i) val_bufs[(i)], sizeof(val_bufs[(i)])
+
   if (afl->total_cal_cycles) avg_us = afl->total_cal_us / afl->total_cal_cycles;
 
   while (q) {
@@ -780,7 +846,7 @@ void show_init_stats(afl_state_t *afl) {
 
   SAYF("\n");
 
-  if (avg_us > ((afl->qemu_mode || afl->unicorn_mode) ? 50000 : 10000))
+  if (avg_us > ((afl->fsrv.qemu_mode || afl->unicorn_mode) ? 50000 : 10000))
     WARNF(cLRD "The target binary is pretty slow! See %s/perf_tips.md.",
           doc_path);
 
@@ -797,10 +863,10 @@ void show_init_stats(afl_state_t *afl) {
 
     if (max_len > 50 * 1024)
       WARNF(cLRD "Some test cases are huge (%s) - see %s/perf_tips.md!",
-            DMS(max_len), doc_path);
+            stringify_mem_size(IB(0), max_len), doc_path);
     else if (max_len > 10 * 1024)
-      WARNF("Some test cases are big (%s) - see %s/perf_tips.md.", DMS(max_len),
-            doc_path);
+      WARNF("Some test cases are big (%s) - see %s/perf_tips.md.",
+            stringify_mem_size(IB(0), max_len), doc_path);
 
     if (afl->useless_at_start && !afl->in_bitmap)
       WARNF(cLRD "Some test cases look useless. Consider using a smaller set.");
@@ -824,7 +890,8 @@ void show_init_stats(afl_state_t *afl) {
       max_bits,
       ((double)afl->total_bitmap_size) /
           (afl->total_bitmap_entries ? afl->total_bitmap_entries : 1),
-      DI(min_us), DI(max_us), DI(avg_us));
+      stringify_int(IB(0), min_us), stringify_int(IB(1), max_us),
+      stringify_int(IB(2), avg_us));
 
   if (!afl->timeout_given) {
 
@@ -868,6 +935,7 @@ void show_init_stats(afl_state_t *afl) {
     afl->hang_tmout = MIN(EXEC_TIMEOUT, afl->fsrv.exec_tmout * 2 + 100);
 
   OKF("All set and ready to roll!");
+#undef IB
 
 }
 
diff --git a/src/afl-fuzz.c b/src/afl-fuzz.c
index b89bccb4..2320be5a 100644
--- a/src/afl-fuzz.c
+++ b/src/afl-fuzz.c
@@ -24,8 +24,7 @@
  */
 
 #include "afl-fuzz.h"
-
-u8 be_quiet = 0;
+#include "cmplog.h"
 
 static u8 *get_libradamsa_path(u8 *own_loc) {
 
@@ -96,8 +95,8 @@ static void usage(afl_state_t *afl, u8 *argv0, int more_help) {
       "Execution control settings:\n"
       "  -p schedule   - power schedules recompute a seed's performance "
       "score.\n"
-      "                  <explore (default), fast, coe, lin, quad, exploit, "
-      "mmopt>\n"
+      "                  <explore(default), fast, coe, lin, quad, exploit, "
+      "mmopt, rare>\n"
       "                  see docs/power_schedules.md\n"
       "  -f file       - location read by the fuzzed program (stdin)\n"
       "  -t msec       - timeout for each run (auto-scaled, 50-%d ms)\n"
@@ -130,12 +129,11 @@ static void usage(afl_state_t *afl, u8 *argv0, int more_help) {
 
       "Testing settings:\n"
       "  -s seed       - use a fixed seed for the RNG\n"
-      "  -V seconds    - fuzz for a maximum total time of seconds then "
-      "terminate\n"
-      "  -E execs      - fuzz for a maximum number of total executions then "
+      "  -V seconds    - fuzz for a specific time then terminate\n"
+      "  -E execs      - fuzz for a approx. no of total executions then "
       "terminate\n"
-      "  Note: -V/-E are not precise, they are checked after a queue entry "
-      "is done\n  which can be many minutes/execs later\n\n"
+      "                  Note: not precise and can have several more "
+      "executions.\n\n"
 
       "Other stuff:\n"
       "  -T text       - text banner to show on the screen\n"
@@ -145,7 +143,7 @@ static void usage(afl_state_t *afl, u8 *argv0, int more_help) {
       "  -B bitmap.txt - mutate a specific test case, use the out/fuzz_bitmap "
       "file\n"
       "  -C            - crash exploration mode (the peruvian rabbit thing)\n"
-      "  -e ext        - File extension for the temporarily generated test "
+      "  -e ext        - file extension for the temporarily generated test "
       "case\n\n",
       argv0, EXEC_TIMEOUT, MEM_LIMIT);
 
@@ -167,6 +165,7 @@ static void usage(afl_state_t *afl, u8 *argv0, int more_help) {
       "AFL_FORCE_UI: force showing the status screen (for virtual consoles)\n"
       "AFL_NO_CPU_RED: avoid red color for showing very high cpu usage\n"
       "AFL_SKIP_CPUFREQ: do not warn about variable cpu clocking\n"
+      "AFL_NO_SNAPSHOT: do not use the snapshot feature (if the snapshot lkm is loaded)\n"
       "AFL_NO_FORKSRV: run target via execve instead of using the forkserver\n"
       "AFL_NO_ARITH: skip arithmetic mutations in deterministic stage\n"
       "AFL_SHUFFLE_QUEUE: reorder the input queue randomly on startup\n"
@@ -199,6 +198,8 @@ static void usage(afl_state_t *afl, u8 *argv0, int more_help) {
 #ifdef USE_PYTHON
   SAYF("Compiled with %s module support, see docs/custom_mutator.md\n",
        (char *)PYTHON_VERSION);
+#else
+  SAYF("Compiled without python module support\n");
 #endif
 
   SAYF("For additional help please consult %s/README.md\n\n", doc_path);
@@ -212,6 +213,8 @@ static void usage(afl_state_t *afl, u8 *argv0, int more_help) {
 
 static int stricmp(char const *a, char const *b) {
 
+  if (!a || !b) FATAL("Null reference");
+
   for (;; ++a, ++b) {
 
     int d;
@@ -230,8 +233,7 @@ int main(int argc, char **argv_orig, char **envp) {
   u64    prev_queued = 0;
   u32    sync_interval_cnt = 0, seek_to, show_help = 0;
   u8 *   extras_dir = 0;
-  u8     mem_limit_given = 0;
-  u8     exit_1 = !!get_afl_env("AFL_BENCH_JUST_ONE");
+  u8     mem_limit_given = 0, exit_1 = 0;
   char **use_argv;
 
   struct timeval  tv;
@@ -245,12 +247,14 @@ int main(int argc, char **argv_orig, char **envp) {
   afl_state_init(afl);
   afl_fsrv_init(&afl->fsrv);
 
+  if (get_afl_env("AFL_DEBUG")) afl->debug = 1;
   read_afl_environment(afl, envp);
+  exit_1 = !!afl->afl_env.afl_bench_just_one;
 
   SAYF(cCYA "afl-fuzz" VERSION cRST
             " based on afl by Michal Zalewski and a big online community\n");
 
-  doc_path = access(DOC_PATH, F_OK) ? (u8 *)"docs" : doc_path;
+  doc_path = access(DOC_PATH, F_OK) != 0 ? (u8 *)"docs" : (u8 *)DOC_PATH;
 
   gettimeofday(&tv, &tz);
   afl->init_seed = tv.tv_sec ^ tv.tv_usec ^ getpid();
@@ -304,6 +308,10 @@ int main(int argc, char **argv_orig, char **envp) {
 
           afl->schedule = MMOPT;
 
+        } else if (!stricmp(optarg, "rare")) {
+
+          afl->schedule = RARE;
+
         } else if (!stricmp(optarg, "explore") || !stricmp(optarg, "default") ||
 
                    !stricmp(optarg, "normal") || !stricmp(optarg, "afl")) {
@@ -493,8 +501,8 @@ int main(int argc, char **argv_orig, char **envp) {
 
       case 'Q':                                                /* QEMU mode */
 
-        if (afl->qemu_mode) FATAL("Multiple -Q options not supported");
-        afl->qemu_mode = 1;
+        if (afl->fsrv.qemu_mode) FATAL("Multiple -Q options not supported");
+        afl->fsrv.qemu_mode = 1;
 
         if (!mem_limit_given) afl->fsrv.mem_limit = MEM_LIMIT_QEMU;
 
@@ -519,7 +527,7 @@ int main(int argc, char **argv_orig, char **envp) {
       case 'W':                                           /* Wine+QEMU mode */
 
         if (afl->use_wine) FATAL("Multiple -W options not supported");
-        afl->qemu_mode = 1;
+        afl->fsrv.qemu_mode = 1;
         afl->use_wine = 1;
 
         if (!mem_limit_given) afl->fsrv.mem_limit = 0;
@@ -682,13 +690,14 @@ int main(int argc, char **argv_orig, char **envp) {
   OKF("MOpt Mutator from github.com/puppet-meteor/MOpt-AFL");
 
   if (afl->sync_id && afl->force_deterministic &&
-      getenv("AFL_CUSTOM_MUTATOR_ONLY"))
+      afl->afl_env.afl_custom_mutator_only)
     WARNF(
         "Using -M master with the AFL_CUSTOM_MUTATOR_ONLY mutator options will "
         "result in no deterministic mutations being done!");
 
   if (afl->fixed_seed) OKF("Running with fixed seed: %u", (u32)afl->init_seed);
   srandom((u32)afl->init_seed);
+  srand((u32)afl->init_seed);  // in case it is a different implementation
 
   if (afl->use_radamsa) {
 
@@ -719,6 +728,16 @@ int main(int argc, char **argv_orig, char **envp) {
 
   }
 
+#if defined(__SANITIZE_ADDRESS__)
+  if (afl->fsrv.mem_limit) {
+
+    WARNF("in the ASAN build we disable all memory limits");
+    afl->fsrv.mem_limit = 0;
+
+  }
+
+#endif
+
   setup_signal_handlers();
   check_asan_opts();
 
@@ -732,7 +751,7 @@ int main(int argc, char **argv_orig, char **envp) {
   if (afl->dumb_mode) {
 
     if (afl->crash_mode) FATAL("-C and -n are mutually exclusive");
-    if (afl->qemu_mode) FATAL("-Q and -n are mutually exclusive");
+    if (afl->fsrv.qemu_mode) FATAL("-Q and -n are mutually exclusive");
     if (afl->unicorn_mode) FATAL("-U and -n are mutually exclusive");
 
   }
@@ -760,8 +779,9 @@ int main(int argc, char **argv_orig, char **envp) {
     case LIN: OKF("Using linear power schedule (LIN)"); break;
     case QUAD: OKF("Using quadratic power schedule (QUAD)"); break;
     case MMOPT: OKF("Using modified MOpt power schedule (MMOPT)"); break;
+    case RARE: OKF("Using rare edge focus power schedule (RARE)"); break;
     case EXPLORE:
-      OKF("Using exploration-based constant power schedule (EXPLORE)");
+      OKF("Using exploration-based constant power schedule (EXPLORE, default)");
       break;
     default: FATAL("Unknown power schedule"); break;
 
@@ -799,7 +819,7 @@ int main(int argc, char **argv_orig, char **envp) {
 
   if (afl->afl_env.afl_preload) {
 
-    if (afl->qemu_mode) {
+    if (afl->fsrv.qemu_mode) {
 
       u8 *qemu_preload = getenv("QEMU_SET_ENV");
       u8 *afl_preload = getenv("AFL_PRELOAD");
@@ -845,7 +865,7 @@ int main(int argc, char **argv_orig, char **envp) {
   check_if_tty(afl);
   if (afl->afl_env.afl_force_ui) afl->not_on_tty = 0;
 
-  if (get_afl_env("AFL_CAL_FAST")) {
+  if (afl->afl_env.afl_cal_fast) {
 
     /* Use less calibration cycles, for slow applications */
     afl->cal_cycles = 3;
@@ -853,8 +873,6 @@ int main(int argc, char **argv_orig, char **envp) {
 
   }
 
-  if (get_afl_env("AFL_DEBUG")) afl->debug = 1;
-
   if (afl->afl_env.afl_custom_mutator_only) {
 
     /* This ensures we don't proceed to havoc/splice */
@@ -902,21 +920,21 @@ int main(int argc, char **argv_orig, char **envp) {
   if ((afl->tmp_dir = afl->afl_env.afl_tmpdir) != NULL &&
       !afl->in_place_resume) {
 
-    char tmpfile[afl->file_extension ? strlen(afl->tmp_dir) + 1 + 10 + 1 +
-                                           strlen(afl->file_extension) + 1
-                                     : strlen(afl->tmp_dir) + 1 + 10 + 1];
+    char tmpfile[PATH_MAX];
+
     if (afl->file_extension) {
 
-      sprintf(tmpfile, "%s/.cur_input.%s", afl->tmp_dir, afl->file_extension);
+      snprintf(tmpfile, PATH_MAX, "%s/.cur_input.%s", afl->tmp_dir,
+               afl->file_extension);
 
     } else {
 
-      sprintf(tmpfile, "%s/.cur_input", afl->tmp_dir);
+      snprintf(tmpfile, PATH_MAX, "%s/.cur_input", afl->tmp_dir);
 
     }
 
-    if (access(tmpfile, F_OK) !=
-        -1)  // there is still a race condition here, but well ...
+    /* there is still a race condition here, but well ... */
+    if (access(tmpfile, F_OK) != -1)
       FATAL(
           "AFL_TMPDIR already has an existing temporary input file: %s - if "
           "this is not from another instance, then just remove the file.",
@@ -968,7 +986,7 @@ int main(int argc, char **argv_orig, char **envp) {
 
     if (afl->unicorn_mode)
       FATAL("CmpLog and Unicorn mode are not compatible at the moment, sorry");
-    if (!afl->qemu_mode) check_binary(afl, afl->cmplog_binary);
+    if (!afl->fsrv.qemu_mode) check_binary(afl, afl->cmplog_binary);
 
   }
 
@@ -976,7 +994,7 @@ int main(int argc, char **argv_orig, char **envp) {
 
   afl->start_time = get_cur_time();
 
-  if (afl->qemu_mode) {
+  if (afl->fsrv.qemu_mode) {
 
     if (afl->use_wine)
       use_argv = get_wine_argv(argv[0], &afl->fsrv.target_path, argc - optind,
@@ -992,6 +1010,21 @@ int main(int argc, char **argv_orig, char **envp) {
   }
 
   afl->argv = use_argv;
+
+  if (afl->cmplog_binary) {
+
+    ACTF("Spawning cmplog forkserver");
+    afl_fsrv_init_dup(&afl->cmplog_fsrv, &afl->fsrv);
+    // TODO: this is semi-nice
+    afl->cmplog_fsrv.trace_bits = afl->fsrv.trace_bits;
+    afl->cmplog_fsrv.qemu_mode = afl->fsrv.qemu_mode;
+    afl->cmplog_fsrv.cmplog_binary = afl->cmplog_binary;
+    afl->cmplog_fsrv.init_child_func = cmplog_exec_child;
+    afl_fsrv_start(&afl->cmplog_fsrv, afl->argv, &afl->stop_soon,
+                   afl->afl_env.afl_debug_child_output);
+
+  }
+
   perform_dry_run(afl);
 
   cull_queue(afl);
@@ -1040,9 +1073,9 @@ int main(int argc, char **argv_orig, char **envp) {
 
       }
 
-      show_stats(afl);
+      // show_stats(afl);
 
-      if (afl->not_on_tty) {
+      if (unlikely(afl->not_on_tty)) {
 
         ACTF("Entering queue cycle %llu.", afl->queue_cycle);
         fflush(stdout);
@@ -1086,64 +1119,15 @@ int main(int argc, char **argv_orig, char **envp) {
     afl->queue_cur = afl->queue_cur->next;
     ++afl->current_entry;
 
-    if (afl->most_time_key == 1) {
-
-      u64 cur_ms_lv = get_cur_time();
-      if (afl->most_time * 1000 < cur_ms_lv - afl->start_time) {
-
-        afl->most_time_key = 2;
-        afl->stop_soon = 2;
-        break;
-
-      }
-
-    }
-
-    if (afl->most_execs_key == 1) {
-
-      if (afl->most_execs <= afl->total_execs) {
-
-        afl->most_execs_key = 2;
-        afl->stop_soon = 2;
-        break;
-
-      }
-
-    }
-
-  }
-
-  if (afl->queue_cur) show_stats(afl);
-
-  /*
-   * ATTENTION - the following 10 lines were copied from a PR to Google's afl
-   * repository - and slightly fixed.
-   * These lines have nothing to do with the purpose of original PR though.
-   * Looks like when an exit condition was completed (AFL_BENCH_JUST_ONE,
-   * AFL_EXIT_WHEN_DONE or AFL_BENCH_UNTIL_CRASH) the child and forkserver
-   * where not killed?
-   */
-  /* if we stopped programmatically, we kill the forkserver and the current
-     runner. if we stopped manually, this is done by the signal handler */
-  if (afl->stop_soon == 2) {
-
-    if (afl->fsrv.child_pid > 0) kill(afl->fsrv.child_pid, SIGKILL);
-    if (afl->fsrv.fsrv_pid > 0) kill(afl->fsrv.fsrv_pid, SIGKILL);
-    if (afl->cmplog_child_pid > 0) kill(afl->cmplog_child_pid, SIGKILL);
-    if (afl->cmplog_fsrv_pid > 0) kill(afl->cmplog_fsrv_pid, SIGKILL);
-    /* Now that we've killed the forkserver, we wait for it to be able to get
-     * rusage stats. */
-    if (waitpid(afl->fsrv.fsrv_pid, NULL, 0) <= 0) { WARNF("error waitpid\n"); }
-
   }
 
   write_bitmap(afl);
-  write_stats_file(afl, 0, 0, 0);
   maybe_update_plot_file(afl, 0, 0);
   save_auto(afl);
 
 stop_fuzzing:
 
+  write_stats_file(afl, 0, 0, 0);
   afl->force_ui_update = 1;  // ensure the screen is reprinted
   show_stats(afl);           // print the screen one last time
 
@@ -1177,6 +1161,7 @@ stop_fuzzing:
   ck_free(afl->fsrv.target_path);
   ck_free(afl->fsrv.out_file);
   ck_free(afl->sync_id);
+  afl_state_deinit(afl);
   free(afl);                                                 /* not tracked */
 
   argv_cpy_free(argv);
diff --git a/src/afl-gcc.c b/src/afl-gcc.c
index b0153b49..32cd36cb 100644
--- a/src/afl-gcc.c
+++ b/src/afl-gcc.c
@@ -142,12 +142,12 @@ static void edit_params(u32 argc, char **argv) {
     if (!strcmp(name, "afl-clang++")) {
 
       u8 *alt_cxx = getenv("AFL_CXX");
-      cc_params[0] = alt_cxx ? alt_cxx : (u8 *)"clang++";
+      cc_params[0] = alt_cxx && *alt_cxx ? alt_cxx : (u8 *)"clang++";
 
     } else {
 
       u8 *alt_cc = getenv("AFL_CC");
-      cc_params[0] = alt_cc ? alt_cc : (u8 *)"clang";
+      cc_params[0] = alt_cc && *alt_cc ? alt_cc : (u8 *)"clang";
 
     }
 
@@ -187,17 +187,17 @@ static void edit_params(u32 argc, char **argv) {
     if (!strcmp(name, "afl-g++")) {
 
       u8 *alt_cxx = getenv("AFL_CXX");
-      cc_params[0] = alt_cxx ? alt_cxx : (u8 *)"g++";
+      cc_params[0] = alt_cxx && *alt_cxx ? alt_cxx : (u8 *)"g++";
 
     } else if (!strcmp(name, "afl-gcj")) {
 
       u8 *alt_cc = getenv("AFL_GCJ");
-      cc_params[0] = alt_cc ? alt_cc : (u8 *)"gcj";
+      cc_params[0] = alt_cc && *alt_cc ? alt_cc : (u8 *)"gcj";
 
     } else {
 
       u8 *alt_cc = getenv("AFL_CC");
-      cc_params[0] = alt_cc ? alt_cc : (u8 *)"gcc";
+      cc_params[0] = alt_cc && *alt_cc ? alt_cc : (u8 *)"gcc";
 
     }
 
diff --git a/src/afl-gotcpu.c b/src/afl-gotcpu.c
index 70ed4dbc..6c2fa147 100644
--- a/src/afl-gotcpu.c
+++ b/src/afl-gotcpu.c
@@ -90,7 +90,7 @@ static u64 get_cpu_usage_us(void) {
 
 static u32 measure_preemption(u32 target_ms) {
 
-  static volatile u32 v1, v2;
+  volatile u32 v1, v2 = 0;
 
   u64 st_t, en_t, st_c, en_c, real_delta, slice_delta;
   s32 loop_repeats = 0;
diff --git a/src/afl-sharedmem.c b/src/afl-sharedmem.c
index 7bdf8d03..9db84e77 100644
--- a/src/afl-sharedmem.c
+++ b/src/afl-sharedmem.c
@@ -95,7 +95,7 @@ void afl_shm_deinit(sharedmem_t *shm) {
 
 /* At exit, remove all leftover maps */
 
-void afl_shm_atexit() {
+void afl_shm_atexit(void) {
 
   LIST_FOREACH(&shm_list, sharedmem_t, { afl_shm_deinit(el); });
 
diff --git a/src/afl-showmap.c b/src/afl-showmap.c
index 0051bbec..c84fa36c 100644
--- a/src/afl-showmap.c
+++ b/src/afl-showmap.c
@@ -59,13 +59,10 @@
 #include <sys/types.h>
 #include <sys/resource.h>
 
-u8 be_quiet;
-
 char *stdin_file;                      /* stdin file                        */
 
 u8 *in_dir,                            /* input folder                      */
-    *doc_path,                         /* Path to docs                      */
-        *at_file = NULL;               /* Substitution string for @@        */
+    *at_file = NULL;              /* Substitution string for @@             */
 
 static u8 *in_data;                    /* Input data                        */
 
@@ -84,8 +81,6 @@ u8 quiet_mode,                         /* Hide non-essential messages?      */
 static volatile u8 stop_soon,          /* Ctrl-C pressed?                   */
     child_crashed;                     /* Child crashed?                    */
 
-static u8 qemu_mode;
-
 /* Classify tuple counts. Instead of mapping to individual bits, as in
    afl-fuzz.c, we map to more user-friendly numbers between 1 and 8. */
 
@@ -157,7 +152,8 @@ static u32 write_results_to_file(afl_forkserver_t *fsrv, u8 *outfile) {
 
   if (!strncmp(outfile, "/dev/", 5)) {
 
-    fd = open(outfile, O_WRONLY, 0600);
+    fd = open(outfile, O_WRONLY);
+
     if (fd < 0) PFATAL("Unable to open '%s'", fsrv->out_file);
 
   } else if (!strcmp(outfile, "-")) {
@@ -224,26 +220,6 @@ static u32 write_results(afl_forkserver_t *fsrv) {
 
 }
 
-/* Write output file. */
-
-static s32 write_to_file(u8 *path, u8 *mem, u32 len) {
-
-  s32 ret;
-
-  unlink(path);                                            /* Ignore errors */
-
-  ret = open(path, O_RDWR | O_CREAT | O_EXCL, 0600);
-
-  if (ret < 0) PFATAL("Unable to create '%s'", path);
-
-  ck_write(ret, mem, len, path);
-
-  lseek(ret, 0, SEEK_SET);
-
-  return ret;
-
-}
-
 /* Write modified data to file for testing. If use_stdin is clear, the old file
    is unlinked and a new one is created. Otherwise, out_fd is rewound and
    truncated. */
@@ -263,9 +239,8 @@ static void write_to_testcase(afl_forkserver_t *fsrv, void *mem, u32 len) {
 static u8 run_target_forkserver(afl_forkserver_t *fsrv, char **argv, u8 *mem,
                                 u32 len) {
 
-  static struct itimerval it;
-  static u32              prev_timed_out = 0;
-  int                     status = 0;
+  struct itimerval it;
+  int              status = 0;
 
   memset(fsrv->trace_bits, 0, MAP_SIZE);
   MEM_BARRIER();
@@ -277,7 +252,7 @@ static u8 run_target_forkserver(afl_forkserver_t *fsrv, char **argv, u8 *mem,
   /* we have the fork server up and running, so simply
      tell it to have at it, and then read back PID. */
 
-  if ((res = write(fsrv->fsrv_ctl_fd, &prev_timed_out, 4)) != 4) {
+  if ((res = write(fsrv->fsrv_ctl_fd, &fsrv->prev_timed_out, 4)) != 4) {
 
     if (stop_soon) return 0;
     RPFATAL(res, "Unable to request new process from fork server (OOM?)");
@@ -505,7 +480,7 @@ static void handle_stop_sig(int sig) {
 
 /* Do basic preparations - persistent fds, filenames, etc. */
 
-static void set_up_environment(void) {
+static void set_up_environment(afl_forkserver_t *fsrv) {
 
   setenv("ASAN_OPTIONS",
          "abort_on_error=1:"
@@ -522,7 +497,7 @@ static void set_up_environment(void) {
 
   if (get_afl_env("AFL_PRELOAD")) {
 
-    if (qemu_mode) {
+    if (fsrv->qemu_mode) {
 
       u8 *qemu_preload = getenv("QEMU_SET_ENV");
       u8 *afl_preload = getenv("AFL_PRELOAD");
@@ -579,11 +554,6 @@ static void setup_signal_handlers(void) {
   sigaction(SIGINT, &sa, NULL);
   sigaction(SIGTERM, &sa, NULL);
 
-  /* Exec timeout notifications. */
-
-  sa.sa_handler = handle_timeout;
-  sigaction(SIGALRM, &sa, NULL);
-
 }
 
 /* Show banner. */
@@ -826,10 +796,10 @@ int main(int argc, char **argv_orig, char **envp) {
 
       case 'Q':
 
-        if (qemu_mode) FATAL("Multiple -Q options not supported");
+        if (fsrv->qemu_mode) FATAL("Multiple -Q options not supported");
         if (!mem_limit_given) fsrv->mem_limit = MEM_LIMIT_QEMU;
 
-        qemu_mode = 1;
+        fsrv->qemu_mode = 1;
         break;
 
       case 'U':
@@ -843,7 +813,7 @@ int main(int argc, char **argv_orig, char **envp) {
       case 'W':                                           /* Wine+QEMU mode */
 
         if (use_wine) FATAL("Multiple -W options not supported");
-        qemu_mode = 1;
+        fsrv->qemu_mode = 1;
         use_wine = 1;
 
         if (!mem_limit_given) fsrv->mem_limit = 0;
@@ -888,7 +858,7 @@ int main(int argc, char **argv_orig, char **envp) {
   fsrv->trace_bits = afl_shm_init(&shm, MAP_SIZE, 0);
   setup_signal_handlers();
 
-  set_up_environment();
+  set_up_environment(fsrv);
 
   find_binary(fsrv, argv[optind]);
 
@@ -913,7 +883,7 @@ int main(int argc, char **argv_orig, char **envp) {
   for (i = optind; i < argc; i++)
     if (strcmp(argv[i], "@@") == 0) arg_offset = i;
 
-  if (qemu_mode) {
+  if (fsrv->qemu_mode) {
 
     if (use_wine)
       use_argv = get_wine_argv(argv[0], &fsrv->target_path, argc - optind,
@@ -979,7 +949,8 @@ int main(int argc, char **argv_orig, char **envp) {
 
     }
 
-    afl_fsrv_start(fsrv, use_argv);
+    afl_fsrv_start(fsrv, use_argv, &stop_soon,
+                   get_afl_env("AFL_DEBUG_CHILD_OUTPUT") ? 1 : 0);
 
     while (done == 0 && (dir_ent = readdir(dir_in))) {
 
diff --git a/src/afl-tmin.c b/src/afl-tmin.c
index 17e9af5a..3be6b2c0 100644
--- a/src/afl-tmin.c
+++ b/src/afl-tmin.c
@@ -61,8 +61,7 @@
 static u8 *mask_bitmap;                /* Mask for trace bits (-B)          */
 
 u8 *in_file,                           /* Minimizer input test case         */
-    *output_file,                      /* Minimizer output file             */
-    *doc_path;                         /* Path to docs                      */
+    *output_file;                      /* Minimizer output file             */
 
 static u8 *in_data;                    /* Input data for trimming           */
 
@@ -77,13 +76,10 @@ u8 crash_mode,                         /* Crash-centric mode?               */
     hang_mode,                         /* Minimize as long as it hangs      */
     exit_crash,                        /* Treat non-zero exit as crash?     */
     edges_only,                        /* Ignore hit counts?                */
-    exact_mode,                        /* Require path match for crashes?   */
-    be_quiet;
+    exact_mode;                        /* Require path match for crashes?   */
 
 static volatile u8 stop_soon;          /* Ctrl-C pressed?                   */
 
-static u8 qemu_mode;
-
 /*
  * forkserver section
  */
@@ -247,166 +243,20 @@ static void write_to_testcase(afl_forkserver_t *fsrv, void *mem, u32 len) {
 
 }
 
-/* Handle timeout signal. */
-/*
-static void handle_timeout(int sig) {
-
-  if (child_pid > 0) {
-
-  child_timed_out = 1;
-    kill(child_pid, SIGKILL);
-
-  } else if (child_pid == -1 && forksrv_pid > 0) {
-
-    child_timed_out = 1;
-    kill(forksrv_pid, SIGKILL);
-
-  }
-
-}
-
-*/
-
-/* start the app and it's forkserver */
-/*
-static void init_forkserver(char **argv) {
-
-  static struct itimerval it;
-  int st_pipe[2], ctl_pipe[2];
-  int status = 0;
-  s32 rlen;
-
-  ACTF("Spinning up the fork server...");
-  if (pipe(st_pipe) || pipe(ctl_pipe)) PFATAL("pipe() failed");
-
-  forksrv_pid = fork();
-
-  if (forksrv_pid < 0) PFATAL("fork() failed");
-
-  if (!forksrv_pid) {
-
-    struct rlimit r;
-
-    if (dup2(use_stdin ? out_fd : dev_null_fd, 0) < 0 ||
-        dup2(dev_null_fd, 1) < 0 ||
-        dup2(dev_null_fd, 2) < 0) {
-
-      *(u32*)trace_bits = EXEC_FAIL_SIG;
-      PFATAL("dup2() failed");
-
-    }
-
-    close(dev_null_fd);
-    close(out_fd);
-
-    setsid();
-
-    if (mem_limit) {
-
-      r.rlim_max = r.rlim_cur = ((rlim_t)mem_limit) << 20;
-
-#ifdef RLIMIT_AS
-
-      setrlimit(RLIMIT_AS, &r); // Ignore errors
-
-#else
-
-      setrlimit(RLIMIT_DATA, &r); // Ignore errors
-
-#endif // ^RLIMIT_AS
-
-    }
-
-    r.rlim_max = r.rlim_cur = 0;
-    setrlimit(RLIMIT_CORE, &r); // Ignore errors
-
-    // Set up control and status pipes, close the unneeded original fds.
-
-    if (dup2(ctl_pipe[0], FORKSRV_FD) < 0) PFATAL("dup2() failed");
-    if (dup2(st_pipe[1], FORKSRV_FD + 1) < 0) PFATAL("dup2() failed");
-
-    close(ctl_pipe[0]);
-    close(ctl_pipe[1]);
-    close(st_pipe[0]);
-    close(st_pipe[1]);
-
-    execv(fsrv->target_path, argv);
-
-    *(u32*)trace_bits = EXEC_FAIL_SIG;
-    exit(0);
-
-  }
-
-  // Close the unneeded endpoints.
-
-  close(ctl_pipe[0]);
-  close(st_pipe[1]);
-
-  fsrv_ctl_fd = ctl_pipe[1];
-  fsrv_st_fd  = st_pipe[0];
-
-  // Configure timeout, wait for child, cancel timeout.
-
-  if (exec_tmout) {
-
-    child_timed_out = 0;
-    it.it_value.tv_sec = (exec_tmout * FORK_WAIT_MULT / 1000);
-    it.it_value.tv_usec = ((exec_tmout * FORK_WAIT_MULT) % 1000) * 1000;
-
-  }
-
-  setitimer(ITIMER_REAL, &it, NULL);
-
-  rlen = read(fsrv_st_fd, &status, 4);
-
-  it.it_value.tv_sec = 0;
-  it.it_value.tv_usec = 0;
-  setitimer(ITIMER_REAL, &it, NULL);
-
-  // If we have a four-byte "hello" message from the server, we're all set.
-  // Otherwise, try to figure out what went wrong.
-
-  if (rlen == 4) {
-
-    ACTF("All right - fork server is up.");
-    return;
-
-  }
-
-  if (waitpid(forksrv_pid, &status, 0) <= 0)
-    PFATAL("waitpid() failed");
-
-  u8 child_crashed;
-
-  if (WIFSIGNALED(status))
-    child_crashed = 1;
-
-  if (child_timed_out)
-    SAYF(cLRD "\n+++ Program timed off +++\n" cRST);
-  else if (stop_soon)
-    SAYF(cLRD "\n+++ Program aborted by user +++\n" cRST);
-  else if (child_crashed)
-    SAYF(cLRD "\n+++ Program killed by signal %u +++\n" cRST, WTERMSIG(status));
-
-}
-
-*/
-
 /* Execute target application. Returns 0 if the changes are a dud, or
    1 if they should be kept. */
 
 static u8 run_target(afl_forkserver_t *fsrv, char **argv, u8 *mem, u32 len,
                      u8 first_run) {
 
-  static struct itimerval it;
-  static u32              prev_timed_out = 0;
-  int                     status = 0;
+  struct itimerval it;
+  int              status = 0;
 
   u32 cksum;
 
   fsrv->child_timed_out = 0;
 
-  memset(fsrv->trace_bits, 0, MAP_SIZE);
+  memset(fsrv->trace_bits, 0, fsrv->map_size);
   MEM_BARRIER();
 
   write_to_testcase(fsrv, mem, len);
@@ -416,7 +266,7 @@ static u8 run_target(afl_forkserver_t *fsrv, char **argv, u8 *mem, u32 len,
   /* we have the fork server up and running, so simply
      tell it to have at it, and then read back PID. */
 
-  if ((res = write(fsrv->fsrv_ctl_fd, &prev_timed_out, 4)) != 4) {
+  if ((res = write(fsrv->fsrv_ctl_fd, &fsrv->prev_timed_out, 4)) != 4) {
 
     if (stop_soon) return 0;
     RPFATAL(res, "Unable to request new process from fork server (OOM?)");
@@ -541,7 +391,7 @@ static u8 run_target(afl_forkserver_t *fsrv, char **argv, u8 *mem, u32 len,
 
   }
 
-  cksum = hash32(fsrv->trace_bits, MAP_SIZE, HASH_CONST);
+  cksum = hash32(fsrv->trace_bits, fsrv->map_size, HASH_CONST);
 
   if (first_run) orig_cksum = cksum;
 
@@ -552,17 +402,6 @@ static u8 run_target(afl_forkserver_t *fsrv, char **argv, u8 *mem, u32 len,
 
 }
 
-/* Find first power of two greater or equal to val. */
-
-static u32 next_p2(u32 val) {
-
-  u32 ret = 1;
-  while (val > ret)
-    ret <<= 1;
-  return ret;
-
-}
-
 /* Actually minimize! */
 
 static void minimize(afl_forkserver_t *fsrv, char **argv) {
@@ -580,7 +419,7 @@ static void minimize(afl_forkserver_t *fsrv, char **argv) {
    * BLOCK NORMALIZATION *
    ***********************/
 
-  set_len = next_p2(in_len / TMIN_SET_STEPS);
+  set_len = next_pow2(in_len / TMIN_SET_STEPS);
   set_pos = 0;
 
   if (set_len < TMIN_SET_MIN_SIZE) set_len = TMIN_SET_MIN_SIZE;
@@ -630,7 +469,7 @@ next_pass:
    * BLOCK DELETION *
    ******************/
 
-  del_len = next_p2(in_len / TRIM_START_STEPS);
+  del_len = next_pow2(in_len / TRIM_START_STEPS);
   stage_o_len = in_len;
 
   ACTF(cBRI "Stage #1: " cRST "Removing blocks of data...");
@@ -905,7 +744,7 @@ static void set_up_environment(afl_forkserver_t *fsrv) {
 
   if (get_afl_env("AFL_PRELOAD")) {
 
-    if (qemu_mode) {
+    if (fsrv->qemu_mode) {
 
       u8 *qemu_preload = getenv("QEMU_SET_ENV");
       u8 *afl_preload = getenv("AFL_PRELOAD");
@@ -962,11 +801,6 @@ static void setup_signal_handlers(void) {
   sigaction(SIGINT, &sa, NULL);
   sigaction(SIGTERM, &sa, NULL);
 
-  /* Exec timeout notifications. */
-
-  sa.sa_handler = handle_timeout;
-  sigaction(SIGALRM, &sa, NULL);
-
 }
 
 /* Display usage hints. */
@@ -1193,10 +1027,10 @@ int main(int argc, char **argv_orig, char **envp) {
 
       case 'Q':
 
-        if (qemu_mode) FATAL("Multiple -Q options not supported");
+        if (fsrv->qemu_mode) FATAL("Multiple -Q options not supported");
         if (!mem_limit_given) fsrv->mem_limit = MEM_LIMIT_QEMU;
 
-        qemu_mode = 1;
+        fsrv->qemu_mode = 1;
         break;
 
       case 'U':
@@ -1210,7 +1044,7 @@ int main(int argc, char **argv_orig, char **envp) {
       case 'W':                                           /* Wine+QEMU mode */
 
         if (use_wine) FATAL("Multiple -W options not supported");
-        qemu_mode = 1;
+        fsrv->qemu_mode = 1;
         use_wine = 1;
 
         if (!mem_limit_given) fsrv->mem_limit = 0;
@@ -1271,7 +1105,7 @@ int main(int argc, char **argv_orig, char **envp) {
   find_binary(fsrv, argv[optind]);
   detect_file_args(argv + optind, fsrv->out_file, &fsrv->use_stdin);
 
-  if (qemu_mode) {
+  if (fsrv->qemu_mode) {
 
     if (use_wine)
       use_argv = get_wine_argv(argv[0], &fsrv->target_path, argc - optind,
@@ -1297,7 +1131,8 @@ int main(int argc, char **argv_orig, char **envp) {
 
   read_initial_file();
 
-  afl_fsrv_start(fsrv, use_argv);
+  afl_fsrv_start(fsrv, use_argv, &stop_soon,
+                 get_afl_env("AFL_DEBUG_CHILD_OUTPUT") ? 1 : 0);
 
   ACTF("Performing dry run (mem limit = %llu MB, timeout = %u ms%s)...",
        fsrv->mem_limit, fsrv->exec_tmout, edges_only ? ", edges only" : "");
diff --git a/src/third_party/libradamsa/Makefile b/src/third_party/libradamsa/GNUmakefile
index c5a78ead..c5a78ead 100644
--- a/src/third_party/libradamsa/Makefile
+++ b/src/third_party/libradamsa/GNUmakefile
diff --git a/src/third_party/libradamsa/libradamsa.c b/src/third_party/libradamsa/libradamsa.c
index f3677fa7..27cf91bc 100644
--- a/src/third_party/libradamsa/libradamsa.c
+++ b/src/third_party/libradamsa/libradamsa.c
@@ -2177,7 +2177,7 @@ static uint llen(word *ptr) {
    return len;
 }
 
-static void set_signal_handler() {
+static void set_signal_handler(void) {
    struct sigaction sa;
    sa.sa_handler = signal_handler;
    sigemptyset(&sa.sa_mask);
@@ -2312,7 +2312,7 @@ static word prim_set(word wptr, hval pos, word val) {
    return (word) new;
 }
 
-static void setdown() {
+static void setdown(void) {
    tcsetattr(0, TCSANOW, &tsettings); /* return stdio settings */
 }
 
@@ -30773,7 +30773,7 @@ int secondary(int nargs, char **argv) {
    return 127;
 }
 
-void radamsa_init() {
+void radamsa_init(void) {
    int nobjs=0, nwords=0;
    hp = (byte *) &heap; /* builtin heap */
    state = IFALSE;
@@ -30815,7 +30815,7 @@ size_t copy_list(uint8_t *ptr, word lispval, size_t max) {
       lispval = G(lispval, 2);              // list   = cdr(list)
    }
    if (lispval != INULL && max == 0) {
-      printf("ERROR: lisp return value was not a proper list. Trailing %lu\n", lispval);
+      printf("ERROR: lisp return value was not a proper list. Trailing %lu\n", (unsigned long)lispval);
    }
    return n;
 }
diff --git a/src/third_party/libradamsa/radamsa.h b/src/third_party/libradamsa/radamsa.h
index d54fa2ec..33cccde4 100644
--- a/src/third_party/libradamsa/radamsa.h
+++ b/src/third_party/libradamsa/radamsa.h
@@ -1,15 +1,13 @@
 #include <inttypes.h>
 #include <stddef.h>
 
-extern void radamsa_init();
+extern void radamsa_init(void);
 
-extern size_t radamsa(uint8_t *ptr, size_t len, 
-                      uint8_t *target, size_t max, 
+extern size_t radamsa(uint8_t *ptr, size_t len,
+                      uint8_t *target, size_t max,
                       unsigned int seed);
 
-extern size_t radamsa_inplace(uint8_t *ptr, 
-                              size_t len, 
-                              size_t max, 
+extern size_t radamsa_inplace(uint8_t *ptr,
+                              size_t len,
+                              size_t max,
                               unsigned int seed);
-
-