Add American Fuzzy Lop (afl) to third_party/afl/

third_party/afl/src/afl-fuzz.c

+/*
+   american fuzzy lop - fuzzer code
+   --------------------------------
+
+   Written and maintained by Michal Zalewski <lcamtuf@google.com>
+
+   Forkserver design by Jann Horn <jannhorn@googlemail.com>
+
+   Copyright 2013, 2014, 2015, 2016 Google Inc. All rights reserved.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at:
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+   This 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.
+
+ */
+
+#define AFL_MAIN
+#define MESSAGES_TO_STDOUT
+
+#define _GNU_SOURCE
+#define _FILE_OFFSET_BITS 64
+
+#include "config.h"
+#include "types.h"
+#include "debug.h"
+#include "alloc-inl.h"
+#include "hash.h"
+
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <errno.h>
+#include <signal.h>
+#include <dirent.h>
+#include <ctype.h>
+#include <fcntl.h>
+#include <termios.h>
+#include <dlfcn.h>
+#include <sched.h>
+
+#include <sys/wait.h>
+#include <sys/time.h>
+#include <sys/shm.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/resource.h>
+#include <sys/mman.h>
+#include <sys/ioctl.h>
+#include <sys/file.h>
+
+#if defined(__APPLE__) || defined(__FreeBSD__) || defined (__OpenBSD__)
+#  include <sys/sysctl.h>
+#endif /* __APPLE__ || __FreeBSD__ || __OpenBSD__ */
+
+/* For supporting -Z on systems that have sched_setaffinity. */
+
+#ifdef __linux__
+#  define HAVE_AFFINITY 1
+#endif /* __linux__ */
+
+/* A toggle to export some variables when building as a library. Not very
+   useful for the general public. */
+
+#ifdef AFL_LIB
+#  define EXP_ST
+#else
+#  define EXP_ST static
+#endif /* ^AFL_LIB */
+
+/* Lots of globals, but mostly for the status UI and other things where it
+   really makes no sense to haul them around as function parameters. */
+
+
+EXP_ST u8 *in_dir,                    /* Input directory with test cases  */
+          *out_file,                  /* File to fuzz, if any             */
+          *out_dir,                   /* Working & output directory       */
+          *sync_dir,                  /* Synchronization directory        */
+          *sync_id,                   /* Fuzzer ID                        */
+          *use_banner,                /* Display banner                   */
+          *in_bitmap,                 /* Input bitmap                     */
+          *doc_path,                  /* Path to documentation dir        */
+          *target_path,               /* Path to target binary            */
+          *orig_cmdline;              /* Original command line            */
+
+EXP_ST u32 exec_tmout = EXEC_TIMEOUT; /* Configurable exec timeout (ms)   */
+EXP_ST u64 mem_limit = MEM_LIMIT;     /* Memory cap for child (MB)        */
+
+static u32 stats_update_freq = 1;     /* Stats update frequency (execs)   */
+
+EXP_ST u8  skip_deterministic,        /* Skip deterministic stages?       */
+           force_deterministic,       /* Force deterministic stages?      */
+           use_splicing,              /* Recombine input files?           */
+           dumb_mode,                 /* Run in non-instrumented mode?    */
+           score_changed,             /* Scoring for favorites changed?   */
+           kill_signal,               /* Signal that killed the child     */
+           resuming_fuzz,             /* Resuming an older fuzzing job?   */
+           timeout_given,             /* Specific timeout given?          */
+           not_on_tty,                /* stdout is not a tty              */
+           term_too_small,            /* terminal dimensions too small    */
+           uses_asan,                 /* Target uses ASAN?                */
+           no_forkserver,             /* Disable forkserver?              */
+           crash_mode,                /* Crash mode! Yeah!                */
+           in_place_resume,           /* Attempt in-place resume?         */
+           auto_changed,              /* Auto-generated tokens changed?   */
+           no_cpu_meter_red,          /* Feng shui on the status screen   */
+           no_var_check,              /* Don't detect variable behavior   */
+           shuffle_queue,             /* Shuffle input queue?             */
+           bitmap_changed = 1,        /* Time to update bitmap?           */
+           qemu_mode,                 /* Running in QEMU mode?            */
+           skip_requested,            /* Skip request, via SIGUSR1        */
+           run_over10m;               /* Run time over 10 minutes?        */
+
+static s32 out_fd,                    /* Persistent fd for out_file       */
+           dev_urandom_fd = -1,       /* Persistent fd for /dev/urandom   */
+           dev_null_fd = -1,          /* Persistent fd for /dev/null      */
+           fsrv_ctl_fd,               /* Fork server control pipe (write) */
+           fsrv_st_fd;                /* Fork server status pipe (read)   */
+
+static s32 forksrv_pid,               /* PID of the fork server           */
+           child_pid = -1,            /* PID of the fuzzed program        */
+           out_dir_fd = -1;           /* FD of the lock file              */
+
+EXP_ST u8* trace_bits;                /* SHM with instrumentation bitmap  */
+
+EXP_ST u8  virgin_bits[MAP_SIZE],     /* Regions yet untouched by fuzzing */
+           virgin_hang[MAP_SIZE],     /* Bits we haven't seen in hangs    */
+           virgin_crash[MAP_SIZE];    /* Bits we haven't seen in crashes  */
+
+static s32 shm_id;                    /* ID of the SHM region             */
+
+static volatile u8 stop_soon,         /* Ctrl-C pressed?                  */
+                   clear_screen = 1,  /* Window resized?                  */
+                   child_timed_out;   /* Traced process timed out?        */
+
+EXP_ST u32 queued_paths,              /* Total number of queued testcases */
+           queued_variable,           /* Testcases with variable behavior */
+           queued_at_start,           /* Total number of initial inputs   */
+           queued_discovered,         /* Items discovered during this run */
+           queued_imported,           /* Items imported via -S            */
+           queued_favored,            /* Paths deemed favorable           */
+           queued_with_cov,           /* Paths with new coverage bytes    */
+           pending_not_fuzzed,        /* Queued but not done yet          */
+           pending_favored,           /* Pending favored paths            */
+           cur_skipped_paths,         /* Abandoned inputs in cur cycle    */
+           cur_depth,                 /* Current path depth               */
+           max_depth,                 /* Max path depth                   */
+           useless_at_start,          /* Number of useless starting paths */
+           current_entry,             /* Current queue entry ID           */
+           havoc_div = 1;             /* Cycle count divisor for havoc    */
+
+EXP_ST u64 total_crashes,             /* Total number of crashes          */
+           unique_crashes,            /* Crashes with unique signatures   */
+           total_hangs,               /* Total number of hangs            */
+           unique_hangs,              /* Hangs with unique signatures     */
+           total_execs,               /* Total execve() calls             */
+           start_time,                /* Unix start time (ms)             */
+           last_path_time,            /* Time for most recent path (ms)   */
+           last_crash_time,           /* Time for most recent crash (ms)  */
+           last_hang_time,            /* Time for most recent hang (ms)   */
+           queue_cycle,               /* Queue round counter              */
+           cycles_wo_finds,           /* Cycles without any new paths     */
+           trim_execs,                /* Execs done to trim input files   */
+           bytes_trim_in,             /* Bytes coming into the trimmer    */
+           bytes_trim_out,            /* Bytes coming outa the trimmer    */
+           blocks_eff_total,          /* Blocks subject to effector maps  */
+           blocks_eff_select;         /* Blocks selected as fuzzable      */
+
+static u32 subseq_hangs;              /* Number of hangs in a row         */
+
+static u8 *stage_name = "init",       /* Name of the current fuzz stage   */
+          *stage_short,               /* Short stage name                 */
+          *syncing_party;             /* Currently syncing with...        */
+
+static s32 stage_cur, stage_max;      /* Stage progression                */
+static s32 splicing_with = -1;        /* Splicing with which test case?   */
+
+static u32 syncing_case;              /* Syncing with case #...           */
+
+static s32 stage_cur_byte,            /* Byte offset of current stage op  */
+           stage_cur_val;             /* Value used for stage op          */
+
+static u8  stage_val_type;            /* Value type (STAGE_VAL_*)         */
+
+static u64 stage_finds[32],           /* Patterns found per fuzz stage    */
+           stage_cycles[32];          /* Execs per fuzz stage             */
+
+static u32 rand_cnt;                  /* Random number counter            */
+
+static u64 total_cal_us,              /* Total calibration time (us)      */
+           total_cal_cycles;          /* Total calibration cycles         */
+
+static u64 total_bitmap_size,         /* Total bit count for all bitmaps  */
+           total_bitmap_entries;      /* Number of bitmaps counted        */
+
+static u32 cpu_core_count;            /* CPU core count                   */
+
+#ifdef HAVE_AFFINITY
+
+static u8  use_affinity;              /* Using -Z                         */
+
+static u32 cpu_aff_main,              /* Affinity for main process        */
+           cpu_aff_child;             /* Affinity for fuzzed child        */
+
+#endif /* HAVE_AFFINITY */
+
+static FILE* plot_file;               /* Gnuplot output file              */
+
+struct queue_entry {
+
+  u8* fname;                          /* File name for the test case      */
+  u32 len;                            /* Input length                     */
+
+  u8  cal_failed,                     /* Calibration failed?              */
+      trim_done,                      /* Trimmed?                         */
+      was_fuzzed,                     /* Had any fuzzing done yet?        */
+      passed_det,                     /* Deterministic stages passed?     */
+      has_new_cov,                    /* Triggers new coverage?           */
+      var_behavior,                   /* Variable behavior?               */
+      favored,                        /* Currently favored?               */
+      fs_redundant;                   /* Marked as redundant in the fs?   */
+
+  u32 bitmap_size,                    /* Number of bits set in bitmap     */
+      exec_cksum;                     /* Checksum of the execution trace  */
+
+  u64 exec_us,                        /* Execution time (us)              */
+      handicap,                       /* Number of queue cycles behind    */
+      depth;                          /* Path depth                       */
+
+  u8* trace_mini;                     /* Trace bytes, if kept             */
+  u32 tc_ref;                         /* Trace bytes ref count            */
+
+  struct queue_entry *next,           /* Next element, if any             */
+                     *next_100;       /* 100 elements ahead               */
+
+};
+
+static struct queue_entry *queue,     /* Fuzzing queue (linked list)      */
+                          *queue_cur, /* Current offset within the queue  */
+                          *queue_top, /* Top of the list                  */
+                          *q_prev100; /* Previous 100 marker              */
+
+static struct queue_entry*
+  top_rated[MAP_SIZE];                /* Top entries for bitmap bytes     */
+
+struct extra_data {
+  u8* data;                           /* Dictionary token data            */
+  u32 len;                            /* Dictionary token length          */
+  u32 hit_cnt;                        /* Use count in the corpus          */
+};
+
+static struct extra_data* extras;     /* Extra tokens to fuzz with        */
+static u32 extras_cnt;                /* Total number of tokens read      */
+
+static struct extra_data* a_extras;   /* Automatically selected extras    */
+static u32 a_extras_cnt;              /* Total number of tokens available */
+
+static u8* (*post_handler)(u8* buf, u32* len);
+
+/* Interesting values, as per config.h */
+
+static s8  interesting_8[]  = { INTERESTING_8 };
+static s16 interesting_16[] = { INTERESTING_8, INTERESTING_16 };
+static s32 interesting_32[] = { INTERESTING_8, INTERESTING_16, INTERESTING_32 };
+
+/* Fuzzing stages */
+
+enum {
+  /* 00 */ STAGE_FLIP1,
+  /* 01 */ STAGE_FLIP2,
+  /* 02 */ STAGE_FLIP4,
+  /* 03 */ STAGE_FLIP8,
+  /* 04 */ STAGE_FLIP16,
+  /* 05 */ STAGE_FLIP32,
+  /* 06 */ STAGE_ARITH8,
+  /* 07 */ STAGE_ARITH16,
+  /* 08 */ STAGE_ARITH32,
+  /* 09 */ STAGE_INTEREST8,
+  /* 10 */ STAGE_INTEREST16,
+  /* 11 */ STAGE_INTEREST32,
+  /* 12 */ STAGE_EXTRAS_UO,
+  /* 13 */ STAGE_EXTRAS_UI,
+  /* 14 */ STAGE_EXTRAS_AO,
+  /* 15 */ STAGE_HAVOC,
+  /* 16 */ STAGE_SPLICE
+};
+
+/* Stage value types */
+
+enum {
+  /* 00 */ STAGE_VAL_NONE,
+  /* 01 */ STAGE_VAL_LE,
+  /* 02 */ STAGE_VAL_BE
+};
+
+/* Execution status fault codes */
+
+enum {
+  /* 00 */ FAULT_NONE,
+  /* 01 */ FAULT_HANG,
+  /* 02 */ FAULT_CRASH,
+  /* 03 */ FAULT_ERROR,
+  /* 04 */ FAULT_NOINST,
+  /* 05 */ FAULT_NOBITS
+};
+
+
+/* Get unix time in milliseconds */
+
+static 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 */
+
+static u64 get_cur_time_us(void) {
+
+  struct timeval tv;
+  struct timezone tz;
+
+  gettimeofday(&tv, &tz);
+
+  return (tv.tv_sec * 1000000ULL) + tv.tv_usec;
+
+}
+
+
+#ifdef HAVE_AFFINITY
+
+/* Set CPU affinity (on systems that support it). */
+
+static void set_cpu_affinity(u32 cpu_id) {
+
+  cpu_set_t c;
+
+  CPU_ZERO(&c);
+  CPU_SET(cpu_id, &c);
+
+  if (sched_setaffinity(0, sizeof(c), &c))
+    PFATAL("sched_setaffinity failed");
+
+}
+
+#endif /* HAVE_AFFINITY */
+
+
+/* Generate a random number (from 0 to limit - 1). This may
+   have slight bias. */
+
+static inline u32 UR(u32 limit) {
+
+  if (!rand_cnt--) {
+
+    u32 seed[2];
+
+    ck_read(dev_urandom_fd, &seed, sizeof(seed), "/dev/urandom");
+
+    srandom(seed[0]);
+    rand_cnt = (RESEED_RNG / 2) + (seed[1] % RESEED_RNG);
+
+  }
+
+  return random() % limit;
+
+}
+
+
+/* Shuffle an array of pointers. Might be slightly biased. */
+
+static void shuffle_ptrs(void** ptrs, u32 cnt) {
+
+  u32 i;
+
+  for (i = 0; i < cnt - 2; i++) {
+
+    u32 j = i + UR(cnt - i);
+    void *s = ptrs[i];
+    ptrs[i] = ptrs[j];
+    ptrs[j] = s;
+
+  }
+
+}
+
+
+#ifndef IGNORE_FINDS
+
+/* Helper function to compare buffers; returns first and last differing offset. We
+   use this to find reasonable locations for splicing two files. */
+
+static void locate_diffs(u8* ptr1, u8* ptr2, u32 len, s32* first, s32* last) {
+
+  s32 f_loc = -1;
+  s32 l_loc = -1;
+  u32 pos;
+
+  for (pos = 0; pos < len; pos++) {
+
+    if (*(ptr1++) != *(ptr2++)) {
+
+      if (f_loc == -1) f_loc = pos;
+      l_loc = pos;
+
+    }
+
+  }
+
+  *first = f_loc;
+  *last = l_loc;
+
+  return;
+
+}
+
+#endif /* !IGNORE_FINDS */
+
+
+/* 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. */
+
+static 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. */
+
+static 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. */
+
+static 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. */
+
+static 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, %u hrs, %u min, %u sec", DI(t_d), t_h, t_m, t_s);
+  return tmp;
+
+}
+
+
+/* Mark deterministic checks as done for a particular queue entry. We use the
+   .state file to avoid repeating deterministic fuzzing when resuming aborted
+   scans. */
+
+static void mark_as_det_done(struct queue_entry* q) {
+
+  u8* fn = strrchr(q->fname, '/');
+  s32 fd;
+
+  fn = alloc_printf("%s/queue/.state/deterministic_done/%s", out_dir, fn + 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;
+
+}
+
+
+/* Mark as variable. Create symlinks if possible to make it easier to examine
+   the files. */
+
+static void mark_as_variable(struct queue_entry* q) {
+
+  u8 *fn = strrchr(q->fname, '/') + 1, *ldest;
+
+  ldest = alloc_printf("../../%s", fn);
+  fn = alloc_printf("%s/queue/.state/variable_behavior/%s", out_dir, fn);
+
+  if (symlink(ldest, fn)) {
+
+    s32 fd = open(fn, O_WRONLY | O_CREAT | O_EXCL, 0600);
+    if (fd < 0) PFATAL("Unable to create '%s'", fn);
+    close(fd);
+
+  }
+
+  ck_free(ldest);
+  ck_free(fn);
+
+  q->var_behavior = 1;
+
+}
+
+
+/* Mark / unmark as redundant (edge-only). This is not used for restoring state,
+   but may be useful for post-processing datasets. */
+
+static void mark_as_redundant(struct queue_entry* q, u8 state) {
+
+  u8* fn;
+  s32 fd;
+
+  if (state == q->fs_redundant) return;
+
+  q->fs_redundant = state;
+
+  fn = strrchr(q->fname, '/');
+  fn = alloc_printf("%s/queue/.state/redundant_edges/%s", out_dir, fn + 1);
+
+  if (state) {
+
+    fd = open(fn, O_WRONLY | O_CREAT | O_EXCL, 0600);
+    if (fd < 0) PFATAL("Unable to create '%s'", fn);
+    close(fd);
+
+  } else {
+
+    if (unlink(fn)) PFATAL("Unable to remove '%s'", fn);
+
+  }
+
+  ck_free(fn);
+
+}
+
+
+/* Append new test case to the queue. */
+
+static void add_to_queue(u8* fname, u32 len, u8 passed_det) {
+
+  struct queue_entry* q = ck_alloc(sizeof(struct queue_entry));
+
+  q->fname        = fname;
+  q->len          = len;
+  q->depth        = cur_depth + 1;
+  q->passed_det   = passed_det;
+
+  if (q->depth > max_depth) max_depth = q->depth;
+
+  if (queue_top) {
+
+    queue_top->next = q;
+    queue_top = q;
+
+  } else q_prev100 = queue = queue_top = q;
+
+  queued_paths++;
+  pending_not_fuzzed++;
+
+  cycles_wo_finds = 0;
+
+  if (!(queued_paths % 100)) {
+
+    q_prev100->next_100 = q;
+    q_prev100 = q;
+
+  }
+
+  last_path_time = get_cur_time();
+
+}
+
+
+/* Destroy the entire queue. */
+
+EXP_ST void destroy_queue(void) {
+
+  struct queue_entry *q = queue, *n;
+
+  while (q) {
+
+    n = q->next;
+    ck_free(q->fname);
+    ck_free(q->trace_mini);
+    ck_free(q);
+    q = n;
+
+  }
+
+}
+
+
+/* Write bitmap to file. The bitmap is useful mostly for the secret
+   -B option, to focus a separate fuzzing session on a particular
+   interesting input without rediscovering all the others. */
+
+EXP_ST void write_bitmap(void) {
+
+  u8* fname;
+  s32 fd;
+
+  if (!bitmap_changed) return;
+  bitmap_changed = 0;
+
+  fname = alloc_printf("%s/fuzz_bitmap", out_dir);
+  fd = open(fname, O_WRONLY | O_CREAT | O_TRUNC, 0600);
+
+  if (fd < 0) PFATAL("Unable to open '%s'", fname);
+
+  ck_write(fd, virgin_bits, MAP_SIZE, fname);
+
+  close(fd);
+  ck_free(fname);
+
+}
+
+
+/* Read bitmap from file. This is for the -B option again. */
+
+EXP_ST void read_bitmap(u8* fname) {
+
+  s32 fd = open(fname, O_RDONLY);
+
+  if (fd < 0) PFATAL("Unable to open '%s'", fname);
+
+  ck_read(fd, virgin_bits, MAP_SIZE, fname);
+
+  close(fd);
+
+}
+
+
+/* Check if the current execution path brings anything new to the table.
+   Update virgin bits to reflect the finds. Returns 1 if the only change is
+   the hit-count for a particular tuple; 2 if there are new tuples seen. 
+   Updates the map, so subsequent calls will always return 0.
+
+   This function is called after every exec() on a fairly large buffer, so
+   it needs to be fast. We do this in 32-bit and 64-bit flavors. */
+
+#define FFL(_b) (0xffULL << ((_b) << 3))
+#define FF(_b)  (0xff << ((_b) << 3))
+
+static inline u8 has_new_bits(u8* virgin_map) {
+
+#ifdef __x86_64__
+
+  u64* current = (u64*)trace_bits;
+  u64* virgin  = (u64*)virgin_map;
+
+  u32  i = (MAP_SIZE >> 3);
+
+#else
+
+  u32* current = (u32*)trace_bits;
+  u32* virgin  = (u32*)virgin_map;
+
+  u32  i = (MAP_SIZE >> 2);
+
+#endif /* ^__x86_64__ */
+
+  u8   ret = 0;
+
+  while (i--) {
+
+#ifdef __x86_64__
+
+    u64 cur = *current;
+    u64 vir = *virgin;
+
+#else
+
+    u32 cur = *current;
+    u32 vir = *virgin;
+
+#endif /* ^__x86_64__ */
+
+    /* Optimize for *current == ~*virgin, since this will almost always be the
+       case. */
+
+    if (cur & vir) {
+
+      if (ret < 2) {
+
+        /* This trace did not have any new bytes yet; see if there's any
+           current[] byte that is non-zero when virgin[] is 0xff. */
+
+#ifdef __x86_64__
+
+        if (((cur & FFL(0)) && (vir & FFL(0)) == FFL(0)) ||
+            ((cur & FFL(1)) && (vir & FFL(1)) == FFL(1)) ||
+            ((cur & FFL(2)) && (vir & FFL(2)) == FFL(2)) ||
+            ((cur & FFL(3)) && (vir & FFL(3)) == FFL(3)) ||
+            ((cur & FFL(4)) && (vir & FFL(4)) == FFL(4)) ||
+            ((cur & FFL(5)) && (vir & FFL(5)) == FFL(5)) ||
+            ((cur & FFL(6)) && (vir & FFL(6)) == FFL(6)) ||
+            ((cur & FFL(7)) && (vir & FFL(7)) == FFL(7))) ret = 2;
+        else ret = 1;
+
+#else
+
+        if (((cur & FF(0)) && (vir & FF(0)) == FF(0)) ||
+            ((cur & FF(1)) && (vir & FF(1)) == FF(1)) ||
+            ((cur & FF(2)) && (vir & FF(2)) == FF(2)) ||
+            ((cur & FF(3)) && (vir & FF(3)) == FF(3))) ret = 2;
+        else ret = 1;
+
+#endif /* ^__x86_64__ */
+
+      }
+
+      *virgin = vir & ~cur;
+
+    }
+
+    current++;
+    virgin++;
+
+  }
+
+  if (ret && virgin_map == virgin_bits) bitmap_changed = 1;
+
+  return ret;
+
+}
+
+
+/* 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. */
+
+static u32 count_bits(u8* mem) {
+
+  u32* ptr = (u32*)mem;
+  u32  i   = (MAP_SIZE >> 2);
+  u32  ret = 0;
+
+  while (i--) {
+
+    u32 v = *(ptr++);
+
+    /* This gets called on the inverse, virgin bitmap; optimize for sparse
+       data. */
+
+    if (v == 0xffffffff) {
+      ret += 32;
+      continue;
+    }
+
+    v -= ((v >> 1) & 0x55555555);
+    v = (v & 0x33333333) + ((v >> 2) & 0x33333333);
+    ret += (((v + (v >> 4)) & 0xF0F0F0F) * 0x01010101) >> 24;
+
+  }
+
+  return ret;
+
+}
+
+
+/* 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. */
+
+static u32 count_bytes(u8* mem) {
+
+  u32* ptr = (u32*)mem;
+  u32  i   = (MAP_SIZE >> 2);
+  u32  ret = 0;
+
+  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++;
+
+  }
+
+  return ret;
+
+}
+
+
+/* Count the number of non-255 bytes set in the bitmap. Used strictly for the
+   status screen, several calls per second or so. */
+
+static u32 count_non_255_bytes(u8* mem) {
+
+  u32* ptr = (u32*)mem;
+  u32  i   = (MAP_SIZE >> 2);
+  u32  ret = 0;
+
+  while (i--) {
+
+    u32 v = *(ptr++);
+
+    /* This is called on the virgin bitmap, so optimize for the most likely
+       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++;
+
+  }
+
+  return ret;
+
+}
+
+
+/* Destructively simplify trace by eliminating hit count information
+   and replacing it with 0x80 or 0x01 depending on whether the tuple
+   is hit or not. Called on every new crash or hang, should be
+   reasonably fast. */
+
+#define AREP4(_sym)   (_sym), (_sym), (_sym), (_sym)
+#define AREP8(_sym)   AREP4(_sym), AREP4(_sym)
+#define AREP16(_sym)  AREP8(_sym), AREP8(_sym)
+#define AREP32(_sym)  AREP16(_sym), AREP16(_sym)
+#define AREP64(_sym)  AREP32(_sym), AREP32(_sym)
+#define AREP128(_sym) AREP64(_sym), AREP64(_sym)
+
+static u8 simplify_lookup[256] = { 
+  /*    4 */ 1, 128, 128, 128,
+  /*   +4 */ AREP4(128),
+  /*   +8 */ AREP8(128),
+  /*  +16 */ AREP16(128),
+  /*  +32 */ AREP32(128),
+  /*  +64 */ AREP64(128),
+  /* +128 */ AREP128(128)
+};
+
+#ifdef __x86_64__
+
+static void simplify_trace(u64* mem) {
+
+  u32 i = MAP_SIZE >> 3;
+
+  while (i--) {
+
+    /* Optimize for sparse bitmaps. */
+
+    if (*mem) {
+
+      u8* mem8 = (u8*)mem;
+
+      mem8[0] = simplify_lookup[mem8[0]];
+      mem8[1] = simplify_lookup[mem8[1]];
+      mem8[2] = simplify_lookup[mem8[2]];
+      mem8[3] = simplify_lookup[mem8[3]];
+      mem8[4] = simplify_lookup[mem8[4]];
+      mem8[5] = simplify_lookup[mem8[5]];
+      mem8[6] = simplify_lookup[mem8[6]];
+      mem8[7] = simplify_lookup[mem8[7]];
+
+    } else *mem = 0x0101010101010101ULL;
+
+    mem++;
+
+  }
+
+}
+
+#else
+
+static void simplify_trace(u32* mem) {
+
+  u32 i = MAP_SIZE >> 2;
+
+  while (i--) {
+
+    /* Optimize for sparse bitmaps. */
+
+    if (*mem) {
+
+      u8* mem8 = (u8*)mem;
+
+      mem8[0] = simplify_lookup[mem8[0]];
+      mem8[1] = simplify_lookup[mem8[1]];
+      mem8[2] = simplify_lookup[mem8[2]];
+      mem8[3] = simplify_lookup[mem8[3]];
+
+    } else *mem = 0x01010101;
+
+    mem++;
+  }
+
+}
+
+#endif /* ^__x86_64__ */
+
+
+/* Destructively classify execution counts in a trace. This is used as a
+   preprocessing step for any newly acquired traces. Called on every exec,
+   must be fast. */
+
+static u8 count_class_lookup[256] = {
+
+  /* 0 - 3:       4 */ 0, 1, 2, 4,
+  /* 4 - 7:      +4 */ AREP4(8),
+  /* 8 - 15:     +8 */ AREP8(16),
+  /* 16 - 31:   +16 */ AREP16(32),
+  /* 32 - 127:  +96 */ AREP64(64), AREP32(64),
+  /* 128+:     +128 */ AREP128(128)
+
+};
+
+#ifdef __x86_64__
+
+static inline void classify_counts(u64* mem) {
+
+  u32 i = MAP_SIZE >> 3;
+
+  while (i--) {
+
+    /* Optimize for sparse bitmaps. */
+
+    if (*mem) {
+
+      u8* mem8 = (u8*)mem;
+
+      mem8[0] = count_class_lookup[mem8[0]];
+      mem8[1] = count_class_lookup[mem8[1]];
+      mem8[2] = count_class_lookup[mem8[2]];
+      mem8[3] = count_class_lookup[mem8[3]];
+      mem8[4] = count_class_lookup[mem8[4]];
+      mem8[5] = count_class_lookup[mem8[5]];
+      mem8[6] = count_class_lookup[mem8[6]];
+      mem8[7] = count_class_lookup[mem8[7]];
+
+    }
+
+    mem++;
+
+  }
+
+}
+
+#else
+
+static inline void classify_counts(u32* mem) {
+
+  u32 i = MAP_SIZE >> 2;
+
+  while (i--) {
+
+    /* Optimize for sparse bitmaps. */
+
+    if (*mem) {
+
+      u8* mem8 = (u8*)mem;
+
+      mem8[0] = count_class_lookup[mem8[0]];
+      mem8[1] = count_class_lookup[mem8[1]];
+      mem8[2] = count_class_lookup[mem8[2]];
+      mem8[3] = count_class_lookup[mem8[3]];
+
+    }
+
+    mem++;
+
+  }
+
+}
+
+#endif /* ^__x86_64__ */
+
+
+/* Get rid of shared memory (atexit handler). */
+
+static void remove_shm(void) {
+
+  shmctl(shm_id, IPC_RMID, NULL);
+
+}
+
+
+/* Compact trace bytes into a smaller bitmap. We effectively just drop the
+   count information here. This is called only sporadically, for some
+   new paths. */
+
+static void minimize_bits(u8* dst, u8* src) {
+
+  u32 i = 0;
+
+  while (i < MAP_SIZE) {
+
+    if (*(src++)) dst[i >> 3] |= 1 << (i & 7);
+    i++;
+
+  }
+
+}
+
+
+/* When we bump into a new path, we call this to see if the path appears
+   more "favorable" than any of the existing ones. The purpose of the
+   "favorables" is to have a minimal set of paths that trigger all the bits
+   seen in the bitmap so far, and focus on fuzzing them at the expense of
+   the rest.
+
+   The first step of the process is to maintain a list of top_rated[] entries
+   for every byte in the bitmap. We win that slot if there is no previous
+   contender, or if the contender has a more favorable speed x size factor. */
+
+static void update_bitmap_score(struct queue_entry* q) {
+
+  u32 i;
+  u64 fav_factor = q->exec_us * q->len;
+
+  /* For every byte set in trace_bits[], see if there is a previous winner,
+     and how it compares to us. */
+
+  for (i = 0; i < MAP_SIZE; i++)
+
+    if (trace_bits[i]) {
+
+       if (top_rated[i]) {
+
+         /* Faster-executing or smaller test cases are favored. */
+
+         if (fav_factor > top_rated[i]->exec_us * top_rated[i]->len) continue;
+
+         /* Looks like we're going to win. Decrease ref count for the
+            previous winner, discard its trace_bits[] if necessary. */
+
+         if (!--top_rated[i]->tc_ref) {
+           ck_free(top_rated[i]->trace_mini);
+           top_rated[i]->trace_mini = 0;
+         }
+
+       }
+
+       /* Insert ourselves as the new winner. */
+
+       top_rated[i] = q;
+       q->tc_ref++;
+
+       if (!q->trace_mini) {
+         q->trace_mini = ck_alloc(MAP_SIZE >> 3);
+         minimize_bits(q->trace_mini, trace_bits);
+       }
+
+       score_changed = 1;
+
+     }
+
+}
+
+
+/* The second part of the mechanism discussed above is a routine that
+   goes over top_rated[] entries, and then sequentially grabs winners for
+   previously-unseen bytes (temp_v) and marks them as favored, at least
+   until the next run. The favored entries are given more air time during
+   all fuzzing steps. */
+
+static void cull_queue(void) {
+
+  struct queue_entry* q;
+  static u8 temp_v[MAP_SIZE >> 3];
+  u32 i;
+
+  if (dumb_mode || !score_changed) return;
+
+  score_changed = 0;
+
+  memset(temp_v, 255, MAP_SIZE >> 3);
+
+  queued_favored  = 0;
+  pending_favored = 0;
+
+  q = queue;
+
+  while (q) {
+    q->favored = 0;
+    q = q->next;
+  }
+
+  /* Let's see if anything in the bitmap isn't captured in temp_v.
+     If yes, and if it has a top_rated[] contender, let's use it. */
+
+  for (i = 0; i < MAP_SIZE; i++)
+    if (top_rated[i] && (temp_v[i >> 3] & (1 << (i & 7)))) {
+
+      u32 j = MAP_SIZE >> 3;
+
+      /* Remove all bits belonging to the current entry from temp_v. */
+
+      while (j--) 
+        if (top_rated[i]->trace_mini[j])
+          temp_v[j] &= ~top_rated[i]->trace_mini[j];
+
+      top_rated[i]->favored = 1;
+      queued_favored++;
+
+      if (!top_rated[i]->was_fuzzed) pending_favored++;
+
+    }
+
+  q = queue;
+
+  while (q) {
+    mark_as_redundant(q, !q->favored);
+    q = q->next;
+  }
+
+}
+
+
+/* Configure shared memory and virgin_bits. This is called at startup. */
+
+EXP_ST void setup_shm(void) {
+
+  u8* shm_str;
+
+  if (!in_bitmap) memset(virgin_bits, 255, MAP_SIZE);
+
+  memset(virgin_hang, 255, MAP_SIZE);
+  memset(virgin_crash, 255, MAP_SIZE);
+
+  shm_id = shmget(IPC_PRIVATE, MAP_SIZE, IPC_CREAT | IPC_EXCL | 0600);
+
+  if (shm_id < 0) PFATAL("shmget() failed");
+
+  atexit(remove_shm);
+
+  shm_str = alloc_printf("%d", shm_id);
+
+  /* If somebody is asking us to fuzz instrumented binaries in dumb mode,
+     we don't want them to detect instrumentation, since we won't be sending
+     fork server commands. This should be replaced with better auto-detection
+     later on, perhaps? */
+
+  if (!dumb_mode) setenv(SHM_ENV_VAR, shm_str, 1);
+
+  ck_free(shm_str);
+
+  trace_bits = shmat(shm_id, NULL, 0);
+  
+  if (!trace_bits) PFATAL("shmat() failed");
+
+}
+
+
+/* Load postprocessor, if available. */
+
+static void setup_post(void) {
+
+  void* dh;
+  u8* fn = getenv("AFL_POST_LIBRARY");
+  u32 tlen = 6;
+
+  if (!fn) return;
+
+  ACTF("Loading postprocessor from '%s'...", fn);
+
+  dh = dlopen(fn, RTLD_NOW);
+  if (!dh) FATAL("%s", dlerror());
+
+  post_handler = dlsym(dh, "afl_postprocess");
+  if (!post_handler) FATAL("Symbol 'afl_postprocess' not found.");
+
+  /* Do a quick test. It's better to segfault now than later =) */
+
+  post_handler("hello", &tlen);
+
+  OKF("Postprocessor installed successfully.");
+
+}
+
+
+/* Read all testcases from the input directory, then queue them for testing.
+   Called at startup. */
+
+static void read_testcases(void) {
+
+  struct dirent **nl;
+  s32 nl_cnt;
+  u32 i;
+  u8* fn;
+
+  /* Auto-detect non-in-place resumption attempts. */
+
+  fn = alloc_printf("%s/queue", in_dir);
+  if (!access(fn, F_OK)) in_dir = fn; else ck_free(fn);
+
+  ACTF("Scanning '%s'...", in_dir);
+
+  /* We use scandir() + alphasort() rather than readdir() because otherwise,
+     the ordering  of test cases would vary somewhat randomly and would be
+     difficult to control. */
+
+  nl_cnt = scandir(in_dir, &nl, NULL, alphasort);
+
+  if (nl_cnt < 0) {
+
+    if (errno == ENOENT || errno == ENOTDIR)
+
+      SAYF("\n" cLRD "[-] " cRST
+           "The input directory does not seem to be valid - try again. The fuzzer needs\n"
+           "    one or more test case to start with - ideally, a small file under 1 kB\n"
+           "    or so. The cases must be stored as regular files directly in the input\n"
+           "    directory.\n");
+
+    PFATAL("Unable to open '%s'", in_dir);
+
+  }
+
+  if (shuffle_queue && nl_cnt > 1) {
+
+    ACTF("Shuffling queue...");
+    shuffle_ptrs((void**)nl, nl_cnt);
+
+  }
+
+  for (i = 0; i < nl_cnt; i++) {
+
+    struct stat st;
+
+    u8* fn = alloc_printf("%s/%s", in_dir, nl[i]->d_name);
+    u8* dfn = alloc_printf("%s/.state/deterministic_done/%s", in_dir, nl[i]->d_name);
+
+    u8  passed_det = 0;
+
+    free(nl[i]); /* not tracked */
+ 
+    if (lstat(fn, &st) || access(fn, R_OK))
+      PFATAL("Unable to access '%s'", fn);
+
+    /* This also takes care of . and .. */
+
+    if (!S_ISREG(st.st_mode) || !st.st_size || strstr(fn, "/README.txt")) {
+
+      ck_free(fn);
+      ck_free(dfn);
+      continue;
+
+    }
+
+    if (st.st_size > MAX_FILE) 
+      FATAL("Test case '%s' is too big (%s, limit is %s)", fn,
+            DMS(st.st_size), DMS(MAX_FILE));
+
+    /* Check for metadata that indicates that deterministic fuzzing
+       is complete for this entry. We don't want to repeat deterministic
+       fuzzing when resuming aborted scans, because it would be pointless
+       and probably very time-consuming. */
+
+    if (!access(dfn, F_OK)) passed_det = 1;
+    ck_free(dfn);
+
+    add_to_queue(fn, st.st_size, passed_det);
+
+  }
+
+  free(nl); /* not tracked */
+
+  if (!queued_paths) {
+
+    SAYF("\n" cLRD "[-] " cRST
+         "Looks like there are no valid test cases in the input directory! The fuzzer\n"
+         "    needs one or more test case to start with - ideally, a small file under\n"
+         "    1 kB or so. The cases must be stored as regular files directly in the\n"
+         "    input directory.\n");
+
+    FATAL("No usable test cases in '%s'", in_dir);
+
+  }
+
+  last_path_time = 0;
+  queued_at_start = queued_paths;
+
+}
+
+
+/* Helper function for load_extras. */
+
+static int compare_extras_len(const void* p1, const void* p2) {
+  struct extra_data *e1 = (struct extra_data*)p1,
+                    *e2 = (struct extra_data*)p2;
+
+  return e1->len - e2->len;
+}
+
+static int compare_extras_use_d(const void* p1, const void* p2) {
+  struct extra_data *e1 = (struct extra_data*)p1,
+                    *e2 = (struct extra_data*)p2;
+
+  return e2->hit_cnt - e1->hit_cnt;
+}
+
+
+/* Read extras from a file, sort by size. */
+
+static void load_extras_file(u8* fname, u32* min_len, u32* max_len,
+                             u32 dict_level) {
+
+  FILE* f;
+  u8  buf[MAX_LINE];
+  u8  *lptr;
+  u32 cur_line = 0;
+
+  f = fopen(fname, "r");
+
+  if (!f) PFATAL("Unable to open '%s'", fname);
+
+  while ((lptr = fgets(buf, MAX_LINE, f))) {
+
+    u8 *rptr, *wptr;
+    u32 klen = 0;
+
+    cur_line++;
+
+    /* Trim on left and right. */
+
+    while (isspace(*lptr)) lptr++;
+
+    rptr = lptr + strlen(lptr) - 1;
+    while (rptr >= lptr && isspace(*rptr)) rptr--;
+    rptr++;
+    *rptr = 0;
+
+    /* Skip empty lines and comments. */
+
+    if (!*lptr || *lptr == '#') continue;
+
+    /* All other lines must end with '"', which we can consume. */
+
+    rptr--;
+
+    if (rptr < lptr || *rptr != '"')
+      FATAL("Malformed name=\"value\" pair in line %u.", cur_line);
+
+    *rptr = 0;
+
+    /* Skip alphanumerics and dashes (label). */
+
+    while (isalnum(*lptr) || *lptr == '_') lptr++;
+
+    /* If @number follows, parse that. */
+
+    if (*lptr == '@') {
+
+      lptr++;
+      if (atoi(lptr) > dict_level) continue;
+      while (isdigit(*lptr)) lptr++;
+
+    }
+
+    /* Skip whitespace and = signs. */
+
+    while (isspace(*lptr) || *lptr == '=') lptr++;
+
+    /* Consume opening '"'. */
+
+    if (*lptr != '"')
+      FATAL("Malformed name=\"keyword\" pair in line %u.", cur_line);
+
+    lptr++;
+
+    if (!*lptr) FATAL("Empty keyword in line %u.", cur_line);
+
+    /* Okay, let's allocate memory and copy data between "...", handling
+       \xNN escaping, \\, and \". */
+
+    extras = ck_realloc_block(extras, (extras_cnt + 1) *
+               sizeof(struct extra_data));
+
+    wptr = extras[extras_cnt].data = ck_alloc(rptr - lptr);
+
+    while (*lptr) {
+
+      char* hexdigits = "0123456789abcdef";
+
+      switch (*lptr) {
+
+        case 1 ... 31:
+        case 128 ... 255:
+          FATAL("Non-printable characters in line %u.", cur_line);
+
+        case '\\':
+
+          lptr++;
+
+          if (*lptr == '\\' || *lptr == '"') {
+            *(wptr++) = *(lptr++);
+            klen++;
+            break;
+          }
+
+          if (*lptr != 'x' || !isxdigit(lptr[1]) || !isxdigit(lptr[2]))
+            FATAL("Invalid escaping (not \\xNN) in line %u.", cur_line);
+
+          *(wptr++) =
+            ((strchr(hexdigits, tolower(lptr[1])) - hexdigits) << 4) |
+            (strchr(hexdigits, tolower(lptr[2])) - hexdigits);
+
+          lptr += 3;
+          klen++;
+
+          break;
+
+        default:
+
+          *(wptr++) = *(lptr++);
+          klen++;
+
+      }
+
+    }
+
+    extras[extras_cnt].len = klen;
+
+    if (extras[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));
+
+    if (*min_len > klen) *min_len = klen;
+    if (*max_len < klen) *max_len = klen;
+
+    extras_cnt++;
+
+  }
+
+  fclose(f);
+
+}
+
+
+/* Read extras from the extras directory and sort them by size. */
+
+static void load_extras(u8* dir) {
+
+  DIR* d;
+  struct dirent* de;
+  u32 min_len = MAX_DICT_FILE, max_len = 0, dict_level = 0;
+  u8* x;
+
+  /* If the name ends with @, extract level and continue. */
+
+  if ((x = strchr(dir, '@'))) {
+
+    *x = 0;
+    dict_level = atoi(x + 1);
+
+  }
+
+  ACTF("Loading extra dictionary from '%s' (level %u)...", dir, dict_level);
+
+  d = opendir(dir);
+
+  if (!d) {
+
+    if (errno == ENOTDIR) {
+      load_extras_file(dir, &min_len, &max_len, dict_level);
+      goto check_and_sort;
+    }
+
+    PFATAL("Unable to open '%s'", dir);
+
+  }
+
+  if (x) FATAL("Dictionary levels not supported for directories.");
+
+  while ((de = readdir(d))) {
+
+    struct stat st;
+    u8* fn = alloc_printf("%s/%s", dir, de->d_name);
+    s32 fd;
+
+    if (lstat(fn, &st) || access(fn, R_OK))
+      PFATAL("Unable to access '%s'", fn);
+
+    /* This also takes care of . and .. */
+    if (!S_ISREG(st.st_mode) || !st.st_size) {
+
+      ck_free(fn);
+      continue;
+
+    }
+
+    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));
+
+    if (min_len > st.st_size) min_len = st.st_size;
+    if (max_len < st.st_size) max_len = st.st_size;
+
+    extras = ck_realloc_block(extras, (extras_cnt + 1) *
+               sizeof(struct extra_data));
+
+    extras[extras_cnt].data = ck_alloc(st.st_size);
+    extras[extras_cnt].len  = st.st_size;
+
+    fd = open(fn, O_RDONLY);
+
+    if (fd < 0) PFATAL("Unable to open '%s'", fn);
+
+    ck_read(fd, extras[extras_cnt].data, st.st_size, fn);
+
+    close(fd);
+    ck_free(fn);
+
+    extras_cnt++;
+
+  }
+
+  closedir(d);
+
+check_and_sort:
+
+  if (!extras_cnt) FATAL("No usable files in '%s'", dir);
+
+  qsort(extras, extras_cnt, sizeof(struct extra_data), compare_extras_len);
+
+  OKF("Loaded %u extra tokens, size range %s to %s.", extras_cnt,
+      DMS(min_len), DMS(max_len));
+
+  if (max_len > 32)
+    WARNF("Some tokens are relatively large (%s) - consider trimming.",
+          DMS(max_len));
+
+  if (extras_cnt > MAX_DET_EXTRAS)
+    WARNF("More than %u tokens - will use them probabilistically.",
+          MAX_DET_EXTRAS);
+
+}
+
+
+
+
+/* Helper function for maybe_add_auto() */
+
+static inline u8 memcmp_nocase(u8* m1, u8* m2, u32 len) {
+
+  while (len--) if (tolower(*(m1++)) ^ tolower(*(m2++))) return 1;
+  return 0;
+
+}
+
+
+/* Maybe add automatic extra. */
+
+static void maybe_add_auto(u8* mem, u32 len) {
+
+  u32 i;
+
+  /* Allow users to specify that they don't want auto dictionaries. */
+
+  if (!MAX_AUTO_EXTRAS || !USE_AUTO_EXTRAS) return;
+
+  /* Skip runs of identical bytes. */
+
+  for (i = 1; i < len; i++)
+    if (mem[0] ^ mem[i]) break;
+
+  if (i == len) return;
+
+  /* Reject builtin interesting values. */
+
+  if (len == 2) {
+
+    i = sizeof(interesting_16) >> 1;
+
+    while (i--) 
+      if (*((u16*)mem) == interesting_16[i] ||
+          *((u16*)mem) == SWAP16(interesting_16[i])) return;
+
+  }
+
+  if (len == 4) {
+
+    i = sizeof(interesting_32) >> 2;
+
+    while (i--) 
+      if (*((u32*)mem) == interesting_32[i] ||
+          *((u32*)mem) == SWAP32(interesting_32[i])) return;
+
+  }
+
+  /* Reject anything that matches existing extras. Do a case-insensitive
+     match. We optimize by exploiting the fact that extras[] are sorted
+     by size. */
+
+  for (i = 0; i < extras_cnt; i++)
+    if (extras[i].len >= len) break;
+
+  for (; i < extras_cnt && extras[i].len == len; i++)
+    if (!memcmp_nocase(extras[i].data, mem, len)) return;
+
+  /* Last but not least, check a_extras[] for matches. There are no
+     guarantees of a particular sort order. */
+
+  auto_changed = 1;
+
+  for (i = 0; i < a_extras_cnt; i++) {
+
+    if (a_extras[i].len == len && !memcmp_nocase(a_extras[i].data, mem, len)) {
+
+      a_extras[i].hit_cnt++;
+      goto sort_a_extras;
+
+    }
+
+  }
+
+  /* At this point, looks like we're dealing with a new entry. So, let's
+     append it if we have room. Otherwise, let's randomly evict some other
+     entry from the bottom half of the list. */
+
+  if (a_extras_cnt < MAX_AUTO_EXTRAS) {
+
+    a_extras = ck_realloc_block(a_extras, (a_extras_cnt + 1) *
+                                sizeof(struct extra_data));
+
+    a_extras[a_extras_cnt].data = ck_memdup(mem, len);
+    a_extras[a_extras_cnt].len  = len;
+    a_extras_cnt++;
+
+  } else {
+
+    i = MAX_AUTO_EXTRAS / 2 +
+        UR((MAX_AUTO_EXTRAS + 1) / 2);
+
+    ck_free(a_extras[i].data);
+
+    a_extras[i].data    = ck_memdup(mem, len);
+    a_extras[i].len     = len;
+    a_extras[i].hit_cnt = 0;
+
+  }
+
+sort_a_extras:
+
+  /* First, sort all auto extras by use count, descending order. */
+
+  qsort(a_extras, a_extras_cnt, sizeof(struct extra_data),
+        compare_extras_use_d);
+
+  /* Then, sort the top USE_AUTO_EXTRAS entries by size. */
+
+  qsort(a_extras, MIN(USE_AUTO_EXTRAS, a_extras_cnt),
+        sizeof(struct extra_data), compare_extras_len);
+
+}
+
+
+/* Save automatically generated extras. */
+
+static void save_auto(void) {
+
+  u32 i;
+
+  if (!auto_changed) return;
+  auto_changed = 0;
+
+  for (i = 0; i < MIN(USE_AUTO_EXTRAS, a_extras_cnt); i++) {
+
+    u8* fn = alloc_printf("%s/queue/.state/auto_extras/auto_%06u", out_dir, i);
+    s32 fd;
+
+    fd = open(fn, O_WRONLY | O_CREAT | O_TRUNC, 0600);
+
+    if (fd < 0) PFATAL("Unable to create '%s'", fn);
+
+    ck_write(fd, a_extras[i].data, a_extras[i].len, fn);
+
+    close(fd);
+    ck_free(fn);
+
+  }
+
+}
+
+
+/* Load automatically generated extras. */
+
+static void load_auto(void) {
+
+  u32 i;
+
+  for (i = 0; i < USE_AUTO_EXTRAS; i++) {
+
+    u8  tmp[MAX_AUTO_EXTRA + 1];
+    u8* fn = alloc_printf("%s/.state/auto_extras/auto_%06u", in_dir, i);
+    s32 fd, len;
+
+    fd = open(fn, O_RDONLY, 0600);
+
+    if (fd < 0) {
+
+      if (errno != ENOENT) PFATAL("Unable to open '%s'", fn);
+      ck_free(fn);
+      break;
+
+    }
+
+    /* We read one byte more to cheaply detect tokens that are too
+       long (and skip them). */
+
+    len = read(fd, tmp, MAX_AUTO_EXTRA + 1);
+
+    if (len < 0) PFATAL("Unable to read from '%s'", fn);
+
+    if (len >= MIN_AUTO_EXTRA && len <= MAX_AUTO_EXTRA)
+      maybe_add_auto(tmp, len);
+
+    close(fd);
+    ck_free(fn);
+
+  }
+
+  if (i) OKF("Loaded %u auto-discovered dictionary tokens.", i);
+  else OKF("No auto-generated dictionary tokens to reuse.");
+
+}
+
+
+/* Destroy extras. */
+
+static void destroy_extras(void) {
+
+  u32 i;
+
+  for (i = 0; i < extras_cnt; i++) 
+    ck_free(extras[i].data);
+
+  ck_free(extras);
+
+  for (i = 0; i < a_extras_cnt; i++) 
+    ck_free(a_extras[i].data);
+
+  ck_free(a_extras);
+
+}
+
+
+/* Spin up fork server (instrumented mode only). The idea is explained here:
+
+   http://lcamtuf.blogspot.com/2014/10/fuzzing-binaries-without-execve.html
+
+   In essence, the instrumentation allows us to skip execve(), and just keep
+   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. */
+
+EXP_ST void init_forkserver(char** argv) {
+
+  static struct itimerval it;
+  int st_pipe[2], ctl_pipe[2];
+  int status;
+  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;
+
+#ifdef HAVE_AFFINITY
+    if (use_affinity) set_cpu_affinity(cpu_aff_child);
+#endif /* HAVE_AFFINITY */
+
+    /* 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 (mem_limit) {
+
+      r.rlim_max = r.rlim_cur = ((rlim_t)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 out_file is
+       specified, stdin is /dev/null; otherwise, out_fd is cloned instead. */
+
+    setsid();
+
+    dup2(dev_null_fd, 1);
+    dup2(dev_null_fd, 2);
+
+    if (out_file) {
+
+      dup2(dev_null_fd, 0);
+
+    } else {
+
+      dup2(out_fd, 0);
+      close(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(out_dir_fd);
+    close(dev_null_fd);
+    close(dev_urandom_fd);
+    close(fileno(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:"
+                           "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:"
+                           "allocator_may_return_null=1:"
+                           "msan_track_origins=0", 0);
+
+    execv(target_path, argv);
+
+    /* Use a distinctive bitmap signature to tell the parent about execv()
+       falling through. */
+
+    *(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];
+
+  /* Wait for the fork server to come up, but don't wait too long. */
+
+  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) {
+    OKF("All right - fork server is up.");
+    return;
+  }
+
+  if (child_timed_out)
+    FATAL("Timeout while initializing fork server (adjusting -t may help)");
+
+  if (waitpid(forksrv_pid, &status, 0) <= 0)
+    PFATAL("waitpid() failed");
+
+  if (WIFSIGNALED(status)) {
+
+    if (mem_limit && mem_limit < 500 && 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.txt for help.\n", doc_path);
+
+    } else if (!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"
+
+#ifdef __APPLE__
+
+           "    - On MacOS X, the semantics of fork() syscalls are non-standard and may\n"
+           "      break afl-fuzz performance optimizations when running platform-specific\n"
+           "      targets. To fix this, set AFL_NO_FORKSRV=1 in the environment.\n\n"
+
+#endif /* __APPLE__ */
+
+           "    - Less likely, there is a horrible bug in the fuzzer. If other options\n"
+           "      fail, poke <lcamtuf@coredump.cx> 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"
+
+#ifdef RLIMIT_AS
+           "      ( ulimit -Sv $[%llu << 10]; /path/to/fuzzed_app )\n\n"
+#else
+           "      ( ulimit -Sd $[%llu << 10]; /path/to/fuzzed_app )\n\n"
+#endif /* ^RLIMIT_AS */
+
+           "      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"
+
+#ifdef __APPLE__
+
+           "    - On MacOS X, the semantics of fork() syscalls are non-standard and may\n"
+           "      break afl-fuzz performance optimizations when running platform-specific\n"
+           "      targets. To fix this, set AFL_NO_FORKSRV=1 in the environment.\n\n"
+
+#endif /* __APPLE__ */
+
+           "    - Less likely, there is a horrible bug in the fuzzer. If other options\n"
+           "      fail, poke <lcamtuf@coredump.cx> for troubleshooting tips.\n",
+           DMS(mem_limit << 20), mem_limit - 1);
+
+    }
+
+    FATAL("Fork server crashed with signal %d", WTERMSIG(status));
+
+  }
+
+  if (*(u32*)trace_bits == EXEC_FAIL_SIG)
+    FATAL("Unable to execute target application ('%s')", argv[0]);
+
+  if (mem_limit && mem_limit < 500 && 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.txt for help.\n", doc_path);
+
+  } else if (!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 <lcamtuf@coredump.cx> 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"
+
+#ifdef RLIMIT_AS
+         "      ( ulimit -Sv $[%llu << 10]; /path/to/fuzzed_app )\n\n"
+#else
+         "      ( ulimit -Sd $[%llu << 10]; /path/to/fuzzed_app )\n\n"
+#endif /* ^RLIMIT_AS */
+
+         "      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 <lcamtuf@coredump.cx> 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(mem_limit << 20), mem_limit - 1);
+
+  }
+
+  FATAL("Fork server handshake failed");
+
+}
+
+
+/* Execute target application, monitoring for timeouts. Return status
+   information. The called program will update trace_bits[]. */
+
+static u8 run_target(char** argv) {
+
+  static struct itimerval it;
+  static u32 prev_timed_out = 0;
+
+  int status = 0;
+  u32 tb4;
+
+  child_timed_out = 0;
+
+  /* After this memset, trace_bits[] are effectively volatile, so we
+     must prevent any earlier operations from venturing into that
+     territory. */
+
+  memset(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 (dumb_mode == 1 || no_forkserver) {
+
+    child_pid = fork();
+
+    if (child_pid < 0) PFATAL("fork() failed");
+
+    if (!child_pid) {
+
+      struct rlimit r;
+
+#ifdef HAVE_AFFINITY
+      if (use_affinity) set_cpu_affinity(cpu_aff_child);
+#endif /* HAVE_AFFINITY */
+
+      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 */
+
+      /* Isolate the process and configure standard descriptors. If out_file is
+         specified, stdin is /dev/null; otherwise, out_fd is cloned instead. */
+
+      setsid();
+
+      dup2(dev_null_fd, 1);
+      dup2(dev_null_fd, 2);
+
+      if (out_file) {
+
+        dup2(dev_null_fd, 0);
+
+      } else {
+
+        dup2(out_fd, 0);
+        close(out_fd);
+
+      }
+
+      /* On Linux, would be faster to use O_CLOEXEC. Maybe TODO. */
+
+      close(dev_null_fd);
+      close(out_dir_fd);
+      close(dev_urandom_fd);
+      close(fileno(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);
+
+      execv(target_path, argv);
+
+      /* Use a distinctive bitmap value to tell the parent about execv()
+         falling through. */
+
+      *(u32*)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(fsrv_ctl_fd, &prev_timed_out, 4)) != 4) {
+
+      if (stop_soon) return 0;
+      RPFATAL(res, "Unable to request new process from fork server (OOM?)");
+
+    }
+
+    if ((res = read(fsrv_st_fd, &child_pid, 4)) != 4) {
+
+      if (stop_soon) return 0;
+      RPFATAL(res, "Unable to request new process from fork server (OOM?)");
+
+    }
+
+    if (child_pid <= 0) FATAL("Fork server is misbehaving (OOM?)");
+
+  }
+
+  /* Configure timeout, as requested by user, then wait for child to terminate. */
+
+  it.it_value.tv_sec = (exec_tmout / 1000);
+  it.it_value.tv_usec = (exec_tmout % 1000) * 1000;
+
+  setitimer(ITIMER_REAL, &it, NULL);
+
+  /* The SIGALRM handler simply kills the child_pid and sets child_timed_out. */
+
+  if (dumb_mode == 1 || no_forkserver) {
+
+    if (waitpid(child_pid, &status, 0) <= 0) PFATAL("waitpid() failed");
+
+  } else {
+
+    s32 res;
+
+    if ((res = read(fsrv_st_fd, &status, 4)) != 4) {
+
+      if (stop_soon) return 0;
+      RPFATAL(res, "Unable to communicate with fork server (OOM?)");
+
+    }
+
+  }
+
+  child_pid = 0;
+  it.it_value.tv_sec = 0;
+  it.it_value.tv_usec = 0;
+
+  setitimer(ITIMER_REAL, &it, NULL);
+
+  total_execs++;
+
+  /* Any subsequent operations on trace_bits must not be moved by the
+     compiler below this point. Past this location, trace_bits[] behave
+     very normally and do not have to be treated as volatile. */
+
+  MEM_BARRIER();
+
+  tb4 = *(u32*)trace_bits;
+
+#ifdef __x86_64__
+  classify_counts((u64*)trace_bits);
+#else
+  classify_counts((u32*)trace_bits);
+#endif /* ^__x86_64__ */
+
+  prev_timed_out = child_timed_out;
+
+  /* Report outcome to caller. */
+
+  if (child_timed_out) return FAULT_HANG;
+
+  if (WIFSIGNALED(status) && !stop_soon) {
+    kill_signal = WTERMSIG(status);
+    return FAULT_CRASH;
+  }
+
+  /* A somewhat nasty hack for MSAN, which doesn't support abort_on_error and
+     must use a special exit code. */
+
+  if (uses_asan && WEXITSTATUS(status) == MSAN_ERROR) {
+    kill_signal = 0;
+    return FAULT_CRASH;
+  }
+
+  if ((dumb_mode == 1 || no_forkserver) && tb4 == EXEC_FAIL_SIG)
+    return FAULT_ERROR;
+
+  return FAULT_NONE;
+
+}
+
+
+/* Write modified data to file for testing. If out_file is set, the old file
+   is unlinked and a new one is created. Otherwise, out_fd is rewound and
+   truncated. */
+
+static void write_to_testcase(void* mem, u32 len) {
+
+  s32 fd = out_fd;
+
+  if (out_file) {
+
+    unlink(out_file); /* Ignore errors. */
+
+    fd = open(out_file, O_WRONLY | O_CREAT | O_EXCL, 0600);
+
+    if (fd < 0) PFATAL("Unable to create '%s'", out_file);
+
+  } else lseek(fd, 0, SEEK_SET);
+
+  ck_write(fd, mem, len, out_file);
+
+  if (!out_file) {
+
+    if (ftruncate(fd, len)) PFATAL("ftruncate() failed");
+    lseek(fd, 0, SEEK_SET);
+
+  } else close(fd);
+
+}
+
+
+/* The same, but with an adjustable gap. Used for trimming. */
+
+static void write_with_gap(void* mem, u32 len, u32 skip_at, u32 skip_len) {
+
+  s32 fd = out_fd;
+  u32 tail_len = len - skip_at - skip_len;
+
+  if (out_file) {
+
+    unlink(out_file); /* Ignore errors. */
+
+    fd = open(out_file, O_WRONLY | O_CREAT | O_EXCL, 0600);
+
+    if (fd < 0) PFATAL("Unable to create '%s'", out_file);
+
+  } else lseek(fd, 0, SEEK_SET);
+
+  if (skip_at) ck_write(fd, mem, skip_at, out_file);
+
+  if (tail_len) ck_write(fd, mem + skip_at + skip_len, tail_len, out_file);
+
+  if (!out_file) {
+
+    if (ftruncate(fd, len - skip_len)) PFATAL("ftruncate() failed");
+    lseek(fd, 0, SEEK_SET);
+
+  } else close(fd);
+
+}
+
+
+static void show_stats(void);
+
+/* Calibrate a new test case. This is done when processing the input directory
+   to warn about flaky or otherwise problematic test cases early on; and when
+   new paths are discovered to detect variable behavior and so on. */
+
+static u8 calibrate_case(char** argv, struct queue_entry* q, u8* use_mem,
+                         u32 handicap, u8 from_queue) {
+
+  u8  fault = 0, new_bits = 0, var_detected = 0, first_run = (q->exec_cksum == 0);
+  u64 start_us, stop_us;
+
+  s32 old_sc = stage_cur, old_sm = stage_max, old_tmout = exec_tmout;
+  u8* old_sn = stage_name;
+
+  /* Be a bit more generous about timeouts when resuming sessions, or when
+     trying to calibrate already-added finds. This helps avoid trouble due
+     to intermittent latency. */
+
+  if (!from_queue || resuming_fuzz)
+    exec_tmout = MAX(exec_tmout + CAL_TMOUT_ADD,
+                     exec_tmout * CAL_TMOUT_PERC / 100);
+
+  q->cal_failed++;
+
+  stage_name = "calibration";
+  stage_max  = no_var_check ? CAL_CYCLES_NO_VAR : CAL_CYCLES;
+
+  /* Make sure the forkserver is up before we do anything, and let's not
+     count its spin-up time toward binary calibration. */
+
+  if (dumb_mode != 1 && !no_forkserver && !forksrv_pid)
+    init_forkserver(argv);
+
+  start_us = get_cur_time_us();
+
+  for (stage_cur = 0; stage_cur < stage_max; stage_cur++) {
+
+    u32 cksum;
+
+    if (!first_run && !(stage_cur % stats_update_freq)) show_stats();
+
+    write_to_testcase(use_mem, q->len);
+
+    fault = run_target(argv);
+
+    /* stop_soon is set by the handler for Ctrl+C. When it's pressed,
+       we want to bail out quickly. */
+
+    if (stop_soon || fault != crash_mode) goto abort_calibration;
+
+    if (!dumb_mode && !stage_cur && !count_bytes(trace_bits)) {
+      fault = FAULT_NOINST;
+      goto abort_calibration;
+    }
+
+    cksum = hash32(trace_bits, MAP_SIZE, HASH_CONST);
+
+    if (q->exec_cksum != cksum) {
+
+      u8 hnb = has_new_bits(virgin_bits);
+      if (hnb > new_bits) new_bits = hnb;
+
+      if (!no_var_check && q->exec_cksum) {
+
+        var_detected = 1;
+        stage_max    = CAL_CYCLES_LONG;
+
+      } else q->exec_cksum = cksum;
+
+    }
+
+  }
+
+  stop_us = get_cur_time_us();
+
+  total_cal_us     += stop_us - start_us;
+  total_cal_cycles += stage_max;
+
+  /* OK, let's collect some stats about the performance of this test case.
+     This is used for fuzzing air time calculations in calculate_score(). */
+
+  q->exec_us     = (stop_us - start_us) / stage_max;
+  q->bitmap_size = count_bytes(trace_bits);
+  q->handicap    = handicap;
+  q->cal_failed  = 0;
+
+  total_bitmap_size += q->bitmap_size;
+  total_bitmap_entries++;
+
+  update_bitmap_score(q);
+
+  /* If this case didn't result in new output from the instrumentation, tell
+     parent. This is a non-critical problem, but something to warn the user
+     about. */
+
+  if (!dumb_mode && first_run && !fault && !new_bits) fault = FAULT_NOBITS;
+
+abort_calibration:
+
+  if (new_bits == 2 && !q->has_new_cov) {
+    q->has_new_cov = 1;
+    queued_with_cov++;
+  }
+
+  /* Mark variable paths. */
+
+  if (var_detected && !q->var_behavior) {
+    mark_as_variable(q);
+    queued_variable++;
+  }
+
+  stage_name = old_sn;
+  stage_cur  = old_sc;
+  stage_max  = old_sm;
+  exec_tmout = old_tmout;
+
+  if (!first_run) show_stats();
+
+  return fault;
+
+}
+
+
+/* Examine map coverage. Called once, for first test case. */
+
+static void check_map_coverage(void) {
+
+  u32 i;
+
+  if (count_bytes(trace_bits) < 100) return;
+
+  for (i = (1 << (MAP_SIZE_POW2 - 1)); i < MAP_SIZE; i++)
+    if (trace_bits[i]) return;
+
+  WARNF("Recompile binary with newer version of afl to improve coverage!");
+
+}
+
+
+/* Perform dry run of all test cases to confirm that the app is working as
+   expected. This is done only for the initial inputs, and only once. */
+
+static void perform_dry_run(char** argv) {
+
+  struct queue_entry* q = queue;
+  u32 cal_failures = 0;
+  u8* skip_crashes = getenv("AFL_SKIP_CRASHES");
+
+  while (q) {
+
+    u8* use_mem;
+    u8  res;
+    s32 fd;
+
+    u8* fn = strrchr(q->fname, '/') + 1;
+
+    ACTF("Attempting dry run with '%s'...", fn);
+
+    fd = open(q->fname, O_RDONLY);
+    if (fd < 0) PFATAL("Unable to open '%s'", q->fname);
+
+    use_mem = ck_alloc_nozero(q->len);
+
+    if (read(fd, use_mem, q->len) != q->len)
+      FATAL("Short read from '%s'", q->fname);
+
+    close(fd);
+
+    res = calibrate_case(argv, q, use_mem, 0, 1);
+    ck_free(use_mem);
+
+    if (stop_soon) return;
+
+    if (res == crash_mode || res == FAULT_NOBITS)
+      SAYF(cGRA "    len = %u, map size = %u, exec speed = %llu us\n" cRST, 
+           q->len, q->bitmap_size, q->exec_us);
+
+    switch (res) {
+
+      case FAULT_NONE:
+
+        if (q == queue) check_map_coverage();
+
+        if (crash_mode) FATAL("Test case '%s' does *NOT* crash", fn);
+
+        break;
+
+      case FAULT_HANG:
+
+        if (timeout_given) {
+
+          /* The -t nn+ syntax in the command line sets timeout_given to '2' and
+             instructs afl-fuzz to tolerate but skip queue entries that time
+             out. */
+
+          if (timeout_given > 1) {
+            WARNF("Test case results in a hang (skipping)");
+            q->cal_failed = CAL_CHANCES;
+            cal_failures++;
+            break;
+          }
+
+          SAYF("\n" cLRD "[-] " cRST
+               "The program took more than %u ms to process one of the initial test cases.\n"
+               "    Usually, the right thing to do is to relax the -t option - or to delete it\n"
+               "    altogether and allow the fuzzer to auto-calibrate. That said, if you know\n"
+               "    what you are doing and want to simply skip the unruly test cases, append\n"
+               "    '+' at the end of the value passed to -t ('-t %u+').\n", exec_tmout,
+               exec_tmout);
+
+          FATAL("Test case '%s' results in a hang", fn);
+
+        } else {
+
+          SAYF("\n" cLRD "[-] " cRST
+               "The program took more than %u ms to process one of the initial test cases.\n"
+               "    This is bad news; raising the limit with the -t option is possible, but\n"
+               "    will probably make the fuzzing process extremely slow.\n\n"
+
+               "    If this test case is just a fluke, the other option is to just avoid it\n"
+               "    altogether, and find one that is less of a CPU hog.\n", exec_tmout);
+
+          FATAL("Test case '%s' results in a hang", fn);
+
+        }
+
+      case FAULT_CRASH:  
+
+        if (crash_mode) break;
+
+        if (skip_crashes) {
+          WARNF("Test case results in a crash (skipping)");
+          q->cal_failed = CAL_CHANCES;
+          cal_failures++;
+          break;
+        }
+
+        if (mem_limit) {
+
+          SAYF("\n" cLRD "[-] " cRST
+               "Oops, the program crashed with one of the test cases provided. There are\n"
+               "    several possible explanations:\n\n"
+
+               "    - The test case causes known crashes under normal working conditions. If\n"
+               "      so, please remove it. The fuzzer should be seeded with interesting\n"
+               "      inputs - but not ones that cause an outright crash.\n\n"
+
+               "    - The current memory limit (%s) is too low for this program, causing\n"
+               "      it to die due to OOM when parsing valid files. To fix this, try\n"
+               "      bumping it up with the -m setting in the command line. If in doubt,\n"
+               "      try something along the lines of:\n\n"
+
+#ifdef RLIMIT_AS
+               "      ( ulimit -Sv $[%llu << 10]; /path/to/binary [...] <testcase )\n\n"
+#else
+               "      ( ulimit -Sd $[%llu << 10]; /path/to/binary [...] <testcase )\n\n"
+#endif /* ^RLIMIT_AS */
+
+               "      Tip: you can use http://jwilk.net/software/recidivm to quickly\n"
+               "      estimate the required amount of virtual memory for the binary. Also,\n"
+               "      if you are using ASAN, see %s/notes_for_asan.txt.\n\n"
+
+#ifdef __APPLE__
+  
+               "    - On MacOS X, the semantics of fork() syscalls are non-standard and may\n"
+               "      break afl-fuzz performance optimizations when running platform-specific\n"
+               "      binaries. To fix this, set AFL_NO_FORKSRV=1 in the environment.\n\n"
+
+#endif /* __APPLE__ */
+
+               "    - Least likely, there is a horrible bug in the fuzzer. If other options\n"
+               "      fail, poke <lcamtuf@coredump.cx> for troubleshooting tips.\n",
+               DMS(mem_limit << 20), mem_limit - 1, doc_path);
+
+        } else {
+
+          SAYF("\n" cLRD "[-] " cRST
+               "Oops, the program crashed with one of the test cases provided. There are\n"
+               "    several possible explanations:\n\n"
+
+               "    - The test case causes known crashes under normal working conditions. If\n"
+               "      so, please remove it. The fuzzer should be seeded with interesting\n"
+               "      inputs - but not ones that cause an outright crash.\n\n"
+
+#ifdef __APPLE__
+  
+               "    - On MacOS X, the semantics of fork() syscalls are non-standard and may\n"
+               "      break afl-fuzz performance optimizations when running platform-specific\n"
+               "      binaries. To fix this, set AFL_NO_FORKSRV=1 in the environment.\n\n"
+
+#endif /* __APPLE__ */
+
+               "    - Least likely, there is a horrible bug in the fuzzer. If other options\n"
+               "      fail, poke <lcamtuf@coredump.cx> for troubleshooting tips.\n");
+
+        }
+
+        FATAL("Test case '%s' results in a crash", fn);
+
+      case FAULT_ERROR:
+
+        FATAL("Unable to execute target application ('%s')", argv[0]);
+
+      case FAULT_NOINST:
+
+        FATAL("No instrumentation detected");
+
+      case FAULT_NOBITS: 
+
+        useless_at_start++;
+
+        if (!in_bitmap && !shuffle_queue)
+          WARNF("No new instrumentation output, test case may be useless.");
+
+        break;
+
+    }
+
+    if (q->var_behavior) WARNF("Instrumentation output varies across runs.");
+
+    q = q->next;
+
+  }
+
+  if (cal_failures) {
+
+    if (cal_failures == queued_paths)
+      FATAL("All test cases time out%s, giving up!",
+            skip_crashes ? " or crash" : "");
+
+    WARNF("Skipped %u test cases (%0.02f%%) due to timeouts%s.", cal_failures,
+          ((double)cal_failures) * 100 / queued_paths,
+          skip_crashes ? " or crashes" : "");
+
+    if (cal_failures * 5 > queued_paths)
+      WARNF(cLRD "High percentage of rejected test cases, check settings!");
+
+  }
+
+  OKF("All test cases processed.");
+
+}
+
+
+/* Helper function: link() if possible, copy otherwise. */
+
+static void link_or_copy(u8* old_path, u8* new_path) {
+
+  s32 i = link(old_path, new_path);
+  s32 sfd, dfd;
+  u8* tmp;
+
+  if (!i) return;
+
+  sfd = open(old_path, O_RDONLY);
+  if (sfd < 0) PFATAL("Unable to open '%s'", old_path);
+
+  dfd = open(new_path, O_WRONLY | O_CREAT | O_EXCL, 0600);
+  if (dfd < 0) PFATAL("Unable to create '%s'", new_path);
+
+  tmp = ck_alloc(64 * 1024);
+
+  while ((i = read(sfd, tmp, 64 * 1024)) > 0) 
+    ck_write(dfd, tmp, i, new_path);
+
+  if (i < 0) PFATAL("read() failed");
+
+  ck_free(tmp);
+  close(sfd);
+  close(dfd);
+
+}
+
+
+static void nuke_resume_dir(void);
+
+/* Create hard links for input test cases in the output directory, choosing
+   good names and pivoting accordingly. */
+
+static void pivot_inputs(void) {
+
+  struct queue_entry* q = queue;
+  u32 id = 0;
+
+  ACTF("Creating hard links for all input files...");
+
+  while (q) {
+
+    u8  *nfn, *rsl = strrchr(q->fname, '/');
+    u32 orig_id;
+
+    if (!rsl) rsl = q->fname; else rsl++;
+
+    /* If the original file name conforms to the syntax and the recorded
+       ID matches the one we'd assign, just use the original file name.
+       This is valuable for resuming fuzzing runs. */
+
+#ifndef SIMPLE_FILES
+#  define CASE_PREFIX "id:"
+#else
+#  define CASE_PREFIX "id_"
+#endif /* ^!SIMPLE_FILES */
+
+    if (!strncmp(rsl, CASE_PREFIX, 3) &&
+        sscanf(rsl + 3, "%06u", &orig_id) == 1 && orig_id == id) {
+
+      u8* src_str;
+      u32 src_id;
+
+      resuming_fuzz = 1;
+      nfn = alloc_printf("%s/queue/%s", out_dir, rsl);
+
+      /* Since we're at it, let's also try to find parent and figure out the
+         appropriate depth for this entry. */
+
+      src_str = strchr(rsl + 3, ':');
+
+      if (src_str && sscanf(src_str + 1, "%06u", &src_id) == 1) {
+
+        struct queue_entry* s = queue;
+        while (src_id-- && s) s = s->next;
+        if (s) q->depth = s->depth + 1;
+
+        if (max_depth < q->depth) max_depth = q->depth;
+
+      }
+
+    } else {
+
+      /* No dice - invent a new name, capturing the original one as a
+         substring. */
+
+#ifndef SIMPLE_FILES
+
+      u8* use_name = strstr(rsl, ",orig:");
+
+      if (use_name) use_name += 6; else use_name = rsl;
+      nfn = alloc_printf("%s/queue/id:%06u,orig:%s", out_dir, id, use_name);
+
+#else
+
+      nfn = alloc_printf("%s/queue/id_%06u", out_dir, id);
+
+#endif /* ^!SIMPLE_FILES */
+
+    }
+
+    /* Pivot to the new queue entry. */
+
+    link_or_copy(q->fname, nfn);
+    ck_free(q->fname);
+    q->fname = nfn;
+
+    /* Make sure that the passed_det value carries over, too. */
+
+    if (q->passed_det) mark_as_det_done(q);
+
+    q = q->next;
+    id++;
+
+  }
+
+  if (in_place_resume) nuke_resume_dir();
+
+}
+
+
+#ifndef SIMPLE_FILES
+
+/* Construct a file name for a new test case, capturing the operation
+   that led to its discovery. Uses a static buffer. */
+
+static u8* describe_op(u8 hnb) {
+
+  static u8 ret[256];
+
+  if (syncing_party) {
+
+    sprintf(ret, "sync:%s,src:%06u", syncing_party, syncing_case);
+
+  } else {
+
+    sprintf(ret, "src:%06u", current_entry);
+
+    if (splicing_with >= 0)
+      sprintf(ret + strlen(ret), "+%06u", splicing_with);
+
+    sprintf(ret + strlen(ret), ",op:%s", stage_short);
+
+    if (stage_cur_byte >= 0) {
+
+      sprintf(ret + strlen(ret), ",pos:%u", stage_cur_byte);
+
+      if (stage_val_type != STAGE_VAL_NONE)
+        sprintf(ret + strlen(ret), ",val:%s%+d", 
+                (stage_val_type == STAGE_VAL_BE) ? "be:" : "",
+                stage_cur_val);
+
+    } else sprintf(ret + strlen(ret), ",rep:%u", stage_cur_val);
+
+  }
+
+  if (hnb == 2) strcat(ret, ",+cov");
+
+  return ret;
+
+}
+
+#endif /* !SIMPLE_FILES */
+
+
+/* Write a message accompanying the crash directory :-) */
+
+static void write_crash_readme(void) {
+
+  u8* fn = alloc_printf("%s/crashes/README.txt", out_dir);
+  s32 fd;
+  FILE* f;
+
+  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;
+
+  f = fdopen(fd, "w");
+
+  if (!f) {
+    close(fd);
+    return;
+  }
+
+  fprintf(f, "Command line used to find this crash:\n\n"
+
+             "%s\n\n"
+
+             "If you can't reproduce a bug outside of afl-fuzz, be sure to set the same\n"
+             "memory limit. The limit used for this fuzzing session was %s.\n\n"
+
+             "Need a tool to minimize test cases before investigating the crashes or sending\n"
+             "them to a vendor? Check out the afl-tmin that comes with the fuzzer!\n\n"
+
+             "Found any cool bugs in open-source tools using afl-fuzz? If yes, please drop\n"
+             "me a mail at <lcamtuf@coredump.cx> once the issues are fixed - I'd love to\n"
+             "add your finds to the gallery at:\n\n"
+
+             "  http://lcamtuf.coredump.cx/afl/\n\n"
+
+             "Thanks :-)\n",
+
+             orig_cmdline, DMS(mem_limit << 20)); /* ignore errors */
+
+  fclose(f);
+
+}
+
+
+/* Check if the result of an execve() during routine fuzzing is interesting,
+   save or queue the input test case for further analysis if so. Returns 1 if
+   entry is saved, 0 otherwise. */
+
+static u8 save_if_interesting(char** argv, void* mem, u32 len, u8 fault) {
+
+  u8  *fn = "";
+  u8  hnb;
+  s32 fd;
+  u8  keeping = 0, res;
+
+  if (fault == crash_mode) {
+
+    /* Keep only if there are new bits in the map, add to queue for
+       future fuzzing, etc. */
+
+    if (!(hnb = has_new_bits(virgin_bits))) {
+      if (crash_mode) total_crashes++;
+      return 0;
+    }    
+
+#ifndef SIMPLE_FILES
+
+    fn = alloc_printf("%s/queue/id:%06u,%s", out_dir, queued_paths,
+                      describe_op(hnb));
+
+#else
+
+    fn = alloc_printf("%s/queue/id_%06u", out_dir, queued_paths);
+
+#endif /* ^!SIMPLE_FILES */
+
+    add_to_queue(fn, len, 0);
+
+    if (hnb == 2) {
+      queue_top->has_new_cov = 1;
+      queued_with_cov++;
+    }
+
+    queue_top->exec_cksum = hash32(trace_bits, MAP_SIZE, HASH_CONST);
+
+    /* Try to calibrate inline; this also calls update_bitmap_score() when
+       successful. */
+
+    res = calibrate_case(argv, queue_top, mem, queue_cycle - 1, 0);
+
+    if (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);
+    close(fd);
+
+    keeping = 1;
+
+  }
+
+  switch (fault) {
+
+    case FAULT_HANG:
+
+      /* Hangs are not very interesting, but we're still obliged to keep
+         a handful of samples. We use the presence of new bits in the
+         hang-specific bitmap as a signal of uniqueness. In "dumb" mode, we
+         just keep everything. */
+
+      total_hangs++;
+
+      if (unique_hangs >= KEEP_UNIQUE_HANG) return keeping;
+
+      if (!dumb_mode) {
+
+#ifdef __x86_64__
+        simplify_trace((u64*)trace_bits);
+#else
+        simplify_trace((u32*)trace_bits);
+#endif /* ^__x86_64__ */
+
+        if (!has_new_bits(virgin_hang)) return keeping;
+
+      }
+
+#ifndef SIMPLE_FILES
+
+      fn = alloc_printf("%s/hangs/id:%06llu,%s", out_dir,
+                        unique_hangs, describe_op(0));
+
+#else
+
+      fn = alloc_printf("%s/hangs/id_%06llu", out_dir,
+                        unique_hangs);
+
+#endif /* ^!SIMPLE_FILES */
+
+      unique_hangs++;
+
+      last_hang_time = get_cur_time();
+
+      break;
+
+    case FAULT_CRASH:
+
+      /* This is handled in a manner roughly similar to hangs,
+         except for slightly different limits. */
+
+      total_crashes++;
+
+      if (unique_crashes >= KEEP_UNIQUE_CRASH) return keeping;
+
+      if (!dumb_mode) {
+
+#ifdef __x86_64__
+        simplify_trace((u64*)trace_bits);
+#else
+        simplify_trace((u32*)trace_bits);
+#endif /* ^__x86_64__ */
+
+        if (!has_new_bits(virgin_crash)) return keeping;
+
+      }
+
+      if (!unique_crashes) write_crash_readme();
+
+#ifndef SIMPLE_FILES
+
+      fn = alloc_printf("%s/crashes/id:%06llu,sig:%02u,%s", out_dir,
+                        unique_crashes, kill_signal, describe_op(0));
+
+#else
+
+      fn = alloc_printf("%s/crashes/id_%06llu_%02u", out_dir, unique_crashes,
+                        kill_signal);
+
+#endif /* ^!SIMPLE_FILES */
+
+      unique_crashes++;
+
+      last_crash_time = get_cur_time();
+
+      break;
+
+    case FAULT_ERROR: FATAL("Unable to execute target application");
+
+    default: return keeping;
+
+  }
+
+  /* If we're here, we apparently want to save the crash or hang
+     test case, too. */
+
+  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);
+  close(fd);
+
+  ck_free(fn);
+
+  return keeping;
+
+}
+
+
+/* When resuming, try to find the queue position to start from. This makes sense
+   only when resuming, and when we can find the original fuzzer_stats. */
+
+static u32 find_start_position(void) {
+
+  static u8 tmp[4096]; /* Ought to be enough for anybody. */
+
+  u8  *fn, *off;
+  s32 fd, i;
+  u32 ret;
+
+  if (!resuming_fuzz) return 0;
+
+  if (in_place_resume) fn = alloc_printf("%s/fuzzer_stats", out_dir);
+  else fn = alloc_printf("%s/../fuzzer_stats", in_dir);
+
+  fd = open(fn, O_RDONLY);
+  ck_free(fn);
+
+  if (fd < 0) return 0;
+
+  i = read(fd, tmp, sizeof(tmp) - 1); (void)i; /* Ignore errors */
+  close(fd);
+
+  off = strstr(tmp, "cur_path       : ");
+  if (!off) return 0;
+
+  ret = atoi(off + 17);
+  if (ret >= queued_paths) ret = 0;
+  return ret;
+
+}
+
+
+/* The same, but for timeouts. The idea is that when resuming sessions without
+   -t given, we don't want to keep auto-scaling the timeout over and over
+   again to prevent it from growing due to random flukes. */
+
+static void find_timeout(void) {
+
+  static u8 tmp[4096]; /* Ought to be enough for anybody. */
+
+  u8  *fn, *off;
+  s32 fd, i;
+  u32 ret;
+
+  if (!resuming_fuzz) return;
+
+  if (in_place_resume) fn = alloc_printf("%s/fuzzer_stats", out_dir);
+  else fn = alloc_printf("%s/../fuzzer_stats", in_dir);
+
+  fd = open(fn, O_RDONLY);
+  ck_free(fn);
+
+  if (fd < 0) return;
+
+  i = read(fd, tmp, sizeof(tmp) - 1); (void)i; /* Ignore errors */
+  close(fd);
+
+  off = strstr(tmp, "exec_timeout   : ");
+  if (!off) return;
+
+  ret = atoi(off + 17);
+  if (ret <= 4) return;
+
+  exec_tmout = ret;
+  timeout_given = 3;
+
+}
+
+
+/* Update stats file for unattended monitoring. */
+
+static void write_stats_file(double bitmap_cvg, double eps) {
+
+  static double last_bcvg, last_eps;
+
+  u8* fn = alloc_printf("%s/fuzzer_stats", out_dir);
+  s32 fd;
+  FILE* f;
+
+  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");
+
+  /* Keep last values in case we're called from another context
+     where exec/sec stats and such are not readily available. */
+
+  if (!bitmap_cvg && !eps) {
+    bitmap_cvg = last_bcvg;
+    eps        = last_eps;
+  } else {
+    last_bcvg = bitmap_cvg;
+    last_eps  = eps;
+  }
+
+  fprintf(f, "start_time     : %llu\n"
+             "last_update    : %llu\n"
+             "fuzzer_pid     : %u\n"
+             "cycles_done    : %llu\n"
+             "execs_done     : %llu\n"
+             "execs_per_sec  : %0.02f\n"
+             "paths_total    : %u\n"
+             "paths_favored  : %u\n"
+             "paths_found    : %u\n"
+             "paths_imported : %u\n"
+             "max_depth      : %u\n"
+             "cur_path       : %u\n"
+             "pending_favs   : %u\n"
+             "pending_total  : %u\n"
+             "variable_paths : %u\n"
+             "bitmap_cvg     : %0.02f%%\n"
+             "unique_crashes : %llu\n"
+             "unique_hangs   : %llu\n"
+             "last_path      : %llu\n"
+             "last_crash     : %llu\n"
+             "last_hang      : %llu\n"
+             "exec_timeout   : %u\n"
+             "afl_banner     : %s\n"
+             "afl_version    : " VERSION "\n"
+             "command_line   : %s\n",
+             start_time / 1000, get_cur_time() / 1000, getpid(),
+             queue_cycle ? (queue_cycle - 1) : 0, total_execs, eps,
+             queued_paths, queued_favored, queued_discovered, queued_imported,
+             max_depth, current_entry, pending_favored, pending_not_fuzzed,
+             queued_variable, bitmap_cvg, unique_crashes, unique_hangs,
+             last_path_time / 1000, last_crash_time / 1000,
+             last_hang_time / 1000, exec_tmout, use_banner, orig_cmdline);
+             /* ignore errors */
+
+  fclose(f);
+
+}
+
+
+/* Update the plot file if there is a reason to. */
+
+static void maybe_update_plot_file(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 == queued_paths && prev_pf == pending_favored && 
+      prev_pnf == pending_not_fuzzed && prev_ce == current_entry &&
+      prev_qc == queue_cycle && prev_uc == unique_crashes &&
+      prev_uh == unique_hangs && prev_md == max_depth) return;
+
+  prev_qp  = queued_paths;
+  prev_pf  = pending_favored;
+  prev_pnf = pending_not_fuzzed;
+  prev_ce  = current_entry;
+  prev_qc  = queue_cycle;
+  prev_uc  = unique_crashes;
+  prev_uh  = unique_hangs;
+  prev_md  = max_depth;
+
+  /* Fields in the file:
+
+     unix_time, cycles_done, cur_path, paths_total, paths_not_fuzzed,
+     favored_not_fuzzed, unique_crashes, unique_hangs, max_depth,
+     execs_per_sec */
+
+  fprintf(plot_file, 
+          "%llu, %llu, %u, %u, %u, %u, %0.02f%%, %llu, %llu, %u, %0.02f\n",
+          get_cur_time() / 1000, queue_cycle - 1, current_entry, queued_paths,
+          pending_not_fuzzed, pending_favored, bitmap_cvg, unique_crashes,
+          unique_hangs, max_depth, eps); /* ignore errors */
+
+  fflush(plot_file);
+
+}
+
+
+
+/* A helper function for maybe_delete_out_dir(), deleting all prefixed
+   files in a directory. */
+
+static u8 delete_files(u8* path, u8* prefix) {
+
+  DIR* d;
+  struct dirent* d_ent;
+
+  d = opendir(path);
+
+  if (!d) return 0;
+
+  while ((d_ent = readdir(d))) {
+
+    if (d_ent->d_name[0] != '.' && (!prefix ||
+        !strncmp(d_ent->d_name, prefix, strlen(prefix)))) {
+
+      u8* fname = alloc_printf("%s/%s", path, d_ent->d_name);
+      if (unlink(fname)) PFATAL("Unable to delete '%s'", fname);
+      ck_free(fname);
+
+    }
+
+  }
+
+  closedir(d);
+
+  return !!rmdir(path);
+
+}
+
+
+/* Get the number of runnable processes, with some simple smoothing. */
+
+static double get_runnable_processes(void) {
+
+  static double res;
+
+#if defined(__APPLE__) || defined(__FreeBSD__) || defined (__OpenBSD__)
+
+  /* I don't see any portable sysctl or so that would quickly give us the
+     number of runnable processes; the 1-minute load average can be a
+     semi-decent approximation, though. */
+
+  if (getloadavg(&res, 1) != 1) return 0;
+
+#else
+
+  /* On Linux, /proc/stat is probably the best way; load averages are
+     computed in funny ways and sometimes don't reflect extremely short-lived
+     processes well. */
+
+  FILE* f = fopen("/proc/stat", "r");
+  u8 tmp[1024];
+  u32 val = 0;
+
+  if (!f) return 0;
+
+  while (fgets(tmp, sizeof(tmp), f)) {
+
+    if (!strncmp(tmp, "procs_running ", 14) ||
+        !strncmp(tmp, "procs_blocked ", 14)) val += atoi(tmp + 14);
+
+  }
+ 
+  fclose(f);
+
+  if (!res) {
+
+    res = val;
+
+  } else {
+
+    res = res * (1.0 - 1.0 / AVG_SMOOTHING) +
+          ((double)val) * (1.0 / AVG_SMOOTHING);
+
+  }
+
+#endif /* ^(__APPLE__ || __FreeBSD__ || __OpenBSD__) */
+
+  return res;
+
+}
+
+
+/* Delete the temporary directory used for in-place session resume. */
+
+static void nuke_resume_dir(void) {
+
+  u8* fn;
+
+  fn = alloc_printf("%s/_resume/.state/deterministic_done", out_dir);
+  if (delete_files(fn, CASE_PREFIX)) goto dir_cleanup_failed;
+  ck_free(fn);
+
+  fn = alloc_printf("%s/_resume/.state/auto_extras", out_dir);
+  if (delete_files(fn, "auto_")) goto dir_cleanup_failed;
+  ck_free(fn);
+
+  fn = alloc_printf("%s/_resume/.state/redundant_edges", out_dir);
+  if (delete_files(fn, CASE_PREFIX)) goto dir_cleanup_failed;
+  ck_free(fn);
+
+  fn = alloc_printf("%s/_resume/.state/variable_behavior", out_dir);
+  if (delete_files(fn, CASE_PREFIX)) goto dir_cleanup_failed;
+  ck_free(fn);
+
+  fn = alloc_printf("%s/_resume/.state", out_dir);
+  if (rmdir(fn) && errno != ENOENT) goto dir_cleanup_failed;
+  ck_free(fn);
+
+  fn = alloc_printf("%s/_resume", out_dir);
+  if (delete_files(fn, CASE_PREFIX)) goto dir_cleanup_failed;
+  ck_free(fn);
+
+  return;
+
+dir_cleanup_failed:
+
+  FATAL("_resume directory cleanup failed");
+
+}
+
+
+/* Delete fuzzer output directory if we recognize it as ours, if the fuzzer
+   is not currently running, and if the last run time isn't too great. */
+
+static void maybe_delete_out_dir(void) {
+
+  FILE* f;
+  u8 *fn = alloc_printf("%s/fuzzer_stats", out_dir);
+
+  /* See if the output directory is locked. If yes, bail out. If not,
+     create a lock that will persist for the lifetime of the process
+     (this requires leaving the descriptor open).*/
+
+  out_dir_fd = open(out_dir, O_RDONLY);
+  if (out_dir_fd < 0) PFATAL("Unable to open '%s'", out_dir);
+
+#ifndef __sun
+
+  if (flock(out_dir_fd, LOCK_EX | LOCK_NB) && errno == EWOULDBLOCK) {
+
+    SAYF("\n" cLRD "[-] " cRST
+         "Looks like the job output directory is being actively used by another\n"
+         "    instance of afl-fuzz. You will need to choose a different %s\n"
+         "    or stop the other process first.\n",
+         sync_id ? "fuzzer ID" : "output location");
+
+    FATAL("Directory '%s' is in use", out_dir);
+
+  }
+
+#endif /* !__sun */
+
+  f = fopen(fn, "r");
+
+  if (f) {
+
+    u64 start_time, last_update;
+
+    if (fscanf(f, "start_time     : %llu\n"
+                  "last_update    : %llu\n", &start_time, &last_update) != 2)
+      FATAL("Malformed data in '%s'", fn);
+
+    fclose(f);
+
+    /* Let's see how much work is at stake. */
+
+    if (!in_place_resume && last_update - start_time > OUTPUT_GRACE * 60) {
+
+      SAYF("\n" cLRD "[-] " cRST
+           "The job output directory already exists and contains the results of more\n"
+           "    than %u minutes worth of fuzzing. To avoid data loss, afl-fuzz will *NOT*\n"
+           "    automatically delete this data for you.\n\n"
+
+           "    If you wish to start a new session, remove or rename the directory manually,\n"
+           "    or specify a different output location for this job. To resume the old\n"
+           "    session, put '-' as the input directory in the command line ('-i -') and\n"
+           "    try again.\n", OUTPUT_GRACE);
+
+       FATAL("At-risk data found in '%s'", out_dir);
+
+    }
+
+  }
+
+  ck_free(fn);
+
+  /* The idea for in-place resume is pretty simple: we temporarily move the old
+     queue/ to a new location that gets deleted once import to the new queue/
+     is finished. If _resume/ already exists, the current queue/ may be
+     incomplete due to an earlier abort, so we want to use the old _resume/
+     dir instead, and we let rename() fail silently. */
+
+  if (in_place_resume) {
+
+    u8* orig_q = alloc_printf("%s/queue", out_dir);
+
+    in_dir = alloc_printf("%s/_resume", out_dir);
+
+    rename(orig_q, in_dir); /* Ignore errors */
+
+    OKF("Output directory exists, will attempt session resume.");
+
+    ck_free(orig_q);
+
+  } else {
+
+    OKF("Output directory exists but deemed OK to reuse.");
+
+  }
+
+  ACTF("Deleting old session data...");
+
+  /* Okay, let's get the ball rolling! First, we need to get rid of the entries
+     in <out_dir>/.synced/.../id:*, if any are present. */
+
+  fn = alloc_printf("%s/.synced", out_dir);
+  if (delete_files(fn, NULL)) goto dir_cleanup_failed;
+  ck_free(fn);
+
+  /* Next, we need to clean up <out_dir>/queue/.state/ subdirectories: */
+
+  fn = alloc_printf("%s/queue/.state/deterministic_done", out_dir);
+  if (delete_files(fn, CASE_PREFIX)) goto dir_cleanup_failed;
+  ck_free(fn);
+
+  fn = alloc_printf("%s/queue/.state/auto_extras", out_dir);
+  if (delete_files(fn, "auto_")) goto dir_cleanup_failed;
+  ck_free(fn);
+
+  fn = alloc_printf("%s/queue/.state/redundant_edges", out_dir);
+  if (delete_files(fn, CASE_PREFIX)) goto dir_cleanup_failed;
+  ck_free(fn);
+
+  fn = alloc_printf("%s/queue/.state/variable_behavior", out_dir);
+  if (delete_files(fn, CASE_PREFIX)) goto dir_cleanup_failed;
+  ck_free(fn);
+
+  /* Then, get rid of the .state subdirectory itself (should be empty by now)
+     and everything matching <out_dir>/queue/id:*. */
+
+  fn = alloc_printf("%s/queue/.state", out_dir);
+  if (rmdir(fn) && errno != ENOENT) goto dir_cleanup_failed;
+  ck_free(fn);
+
+  fn = alloc_printf("%s/queue", out_dir);
+  if (delete_files(fn, CASE_PREFIX)) goto dir_cleanup_failed;
+  ck_free(fn);
+
+  /* All right, let's do <out_dir>/crashes/id:* and <out_dir>/hangs/id:*. */
+
+  if (!in_place_resume) {
+
+    fn = alloc_printf("%s/crashes/README.txt", out_dir);
+    unlink(fn); /* Ignore errors */
+    ck_free(fn);
+
+  }
+
+  fn = alloc_printf("%s/crashes", out_dir);
+
+  /* Make backup of the crashes directory if it's not empty and if we're
+     doing in-place resume. */
+
+  if (in_place_resume && rmdir(fn)) {
+
+    time_t cur_t = time(0);
+    struct tm* t = localtime(&cur_t);
+
+#ifndef SIMPLE_FILES
+
+    u8* nfn = alloc_printf("%s.%04u-%02u-%02u-%02u:%02u:%02u", fn,
+                           t->tm_year + 1900, t->tm_mon + 1, t->tm_mday,
+                           t->tm_hour, t->tm_min, t->tm_sec);
+
+#else
+
+    u8* nfn = alloc_printf("%s_%04u%02u%02u%02u%02u%02u", fn,
+                           t->tm_year + 1900, t->tm_mon + 1, t->tm_mday,
+                           t->tm_hour, t->tm_min, t->tm_sec);
+
+#endif /* ^!SIMPLE_FILES */
+
+    rename(fn, nfn); /* Ignore errors. */
+    ck_free(nfn);
+
+  }
+
+  if (delete_files(fn, CASE_PREFIX)) goto dir_cleanup_failed;
+  ck_free(fn);
+
+  fn = alloc_printf("%s/hangs", out_dir);
+
+  /* Backup hangs, too. */
+
+  if (in_place_resume && rmdir(fn)) {
+
+    time_t cur_t = time(0);
+    struct tm* t = localtime(&cur_t);
+
+#ifndef SIMPLE_FILES
+
+    u8* nfn = alloc_printf("%s.%04u-%02u-%02u-%02u:%02u:%02u", fn,
+                           t->tm_year + 1900, t->tm_mon + 1, t->tm_mday,
+                           t->tm_hour, t->tm_min, t->tm_sec);
+
+#else
+
+    u8* nfn = alloc_printf("%s_%04u%02u%02u%02u%02u%02u", fn,
+                           t->tm_year + 1900, t->tm_mon + 1, t->tm_mday,
+                           t->tm_hour, t->tm_min, t->tm_sec);
+
+#endif /* ^!SIMPLE_FILES */
+
+    rename(fn, nfn); /* Ignore errors. */
+    ck_free(nfn);
+
+  }
+
+  if (delete_files(fn, CASE_PREFIX)) goto dir_cleanup_failed;
+  ck_free(fn);
+
+  /* And now, for some finishing touches. */
+
+  fn = alloc_printf("%s/.cur_input", out_dir);
+  if (unlink(fn) && errno != ENOENT) goto dir_cleanup_failed;
+  ck_free(fn);
+
+  fn = alloc_printf("%s/fuzz_bitmap", out_dir);
+  if (unlink(fn) && errno != ENOENT) goto dir_cleanup_failed;
+  ck_free(fn);
+
+  if (!in_place_resume) {
+    fn  = alloc_printf("%s/fuzzer_stats", out_dir);
+    if (unlink(fn) && errno != ENOENT) goto dir_cleanup_failed;
+    ck_free(fn);
+  }
+
+  fn = alloc_printf("%s/plot_data", out_dir);
+  if (unlink(fn) && errno != ENOENT) goto dir_cleanup_failed;
+  ck_free(fn);
+
+  OKF("Output dir cleanup successful.");
+
+  /* Wow... is that all? If yes, celebrate! */
+
+  return;
+
+dir_cleanup_failed:
+
+  SAYF("\n" cLRD "[-] " cRST
+       "Whoops, the fuzzer tried to reuse your output directory, but bumped into\n"
+       "    some files that shouldn't be there or that couldn't be removed - so it\n"
+       "    decided to abort! This happened while processing this path:\n\n"
+
+       "    %s\n\n"
+       "    Please examine and manually delete the files, or specify a different\n"
+       "    output location for the tool.\n", fn);
+
+  FATAL("Output directory cleanup failed");
+
+}
+
+
+static void check_term_size(void);
+
+
+/* A spiffy retro stats screen! This is called every stats_update_freq
+   execve() calls, plus in several other circumstances. */
+
+static void show_stats(void) {
+
+  static u64 last_stats_ms, last_plot_ms, last_ms, last_execs;
+  static double avg_exec;
+  double t_byte_ratio;
+
+  u64 cur_ms;
+  u32 t_bytes, t_bits;
+
+  u32 banner_len, banner_pad;
+  u8  tmp[256];
+
+  cur_ms = get_cur_time();
+
+  /* If not enough time has passed since last UI update, bail out. */
+
+  if (cur_ms - last_ms < 1000 / UI_TARGET_HZ) return;
+
+  /* Check if we're past the 10 minute mark. */
+
+  if (cur_ms - start_time > 10 * 60 * 1000) run_over10m = 1;
+
+  /* Calculate smoothed exec speed stats. */
+
+  if (!last_execs) {
+  
+    avg_exec = ((double)total_execs) * 1000 / (cur_ms - start_time);
+
+  } else {
+
+    double cur_avg = ((double)(total_execs - last_execs)) * 1000 /
+                     (cur_ms - 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;
+
+    avg_exec = avg_exec * (1.0 - 1.0 / AVG_SMOOTHING) +
+               cur_avg * (1.0 / AVG_SMOOTHING);
+
+  }
+
+  last_ms = cur_ms;
+  last_execs = total_execs;
+
+  /* Tell the callers when to contact us (as measured in execs). */
+
+  stats_update_freq = avg_exec / (UI_TARGET_HZ * 10);
+  if (!stats_update_freq) stats_update_freq = 1;
+
+  /* Do some bitmap stats. */
+
+  t_bytes = count_non_255_bytes(virgin_bits);
+  t_byte_ratio = ((double)t_bytes * 100) / MAP_SIZE;
+
+  /* Roughly every minute, update fuzzer stats and save auto tokens. */
+
+  if (cur_ms - last_stats_ms > STATS_UPDATE_SEC * 1000) {
+
+    last_stats_ms = cur_ms;
+    write_stats_file(t_byte_ratio, avg_exec);
+    save_auto();
+    write_bitmap();
+
+  }
+
+  /* Every now and then, write plot data. */
+
+  if (cur_ms - last_plot_ms > PLOT_UPDATE_SEC * 1000) {
+
+    last_plot_ms = cur_ms;
+    maybe_update_plot_file(t_byte_ratio, avg_exec);
+ 
+  }
+
+  /* Honor AFL_EXIT_WHEN_DONE and AFL_BENCH_UNTIL_CRASH. */
+
+  if (!dumb_mode && cycles_wo_finds > 20 && !pending_not_fuzzed &&
+      getenv("AFL_EXIT_WHEN_DONE")) stop_soon = 2;
+
+  if (total_crashes && getenv("AFL_BENCH_UNTIL_CRASH")) stop_soon = 2;
+
+  /* If we're not on TTY, bail out. */
+
+  if (not_on_tty) return;
+
+  /* Compute some mildly useful bitmap stats. */
+
+  t_bits = (MAP_SIZE << 3) - count_bits(virgin_bits);
+
+  /* Now, for the visuals... */
+
+  if (clear_screen) {
+
+    SAYF(TERM_CLEAR CURSOR_HIDE);
+    clear_screen = 0;
+
+    check_term_size();
+
+  }
+
+  SAYF(TERM_HOME);
+
+  if (term_too_small) {
+
+    SAYF(cBRI "Your terminal is too small to display the UI.\n"
+         "Please resize terminal window to at least 80x25.\n" cRST);
+
+    return;
+
+  }
+
+  /* Let's start by drawing a centered banner. */
+
+  banner_len = (crash_mode ? 24 : 22) + strlen(VERSION) + strlen(use_banner);
+  banner_pad = (80 - banner_len) / 2;
+  memset(tmp, ' ', banner_pad);
+
+  sprintf(tmp + banner_pad, "%s " cLCY VERSION cLGN
+          " (%s)",  crash_mode ? cPIN "peruvian were-rabbit" : 
+          cYEL "american fuzzy lop", use_banner);
+
+  SAYF("\n%s\n\n", tmp);
+
+  /* "Handy" shortcuts for drawing boxes... */
+
+#define bSTG    bSTART cGRA
+#define bH2     bH bH
+#define bH5     bH2 bH2 bH
+#define bH10    bH5 bH5
+#define bH20    bH10 bH10
+#define bH30    bH20 bH10
+#define SP5     "     "
+#define SP10    SP5 SP5
+#define SP20    SP10 SP10
+
+  /* Lord, forgive me this. */
+
+  SAYF(SET_G1 bSTG bLT bH bSTOP cCYA " process timing " bSTG bH30 bH5 bH2 bHB
+       bH bSTOP cCYA " overall results " bSTG bH5 bRT "\n");
+
+  if (dumb_mode) {
+
+    strcpy(tmp, cRST);
+
+  } else {
+
+    /* First queue cycle: don't stop now! */
+    if (queue_cycle == 1) strcpy(tmp, cMGN); else
+
+    /* Subsequent cycles, but we're still making finds. */
+    if (cycles_wo_finds < 3) strcpy(tmp, cYEL); else
+
+    /* No finds for a long time and no test cases to try. */
+    if (cycles_wo_finds > 20 && !pending_not_fuzzed) strcpy(tmp, cLGN);
+
+    /* Default: cautiously OK to stop? */
+    else strcpy(tmp, cLBL);
+
+  }
+
+  SAYF(bV bSTOP "        run time : " cRST "%-34s " bSTG bV bSTOP
+       "  cycles done : %s%-5s  " bSTG bV "\n",
+       DTD(cur_ms, start_time), tmp, DI(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. */
+
+  if (!dumb_mode && (last_path_time || resuming_fuzz || queue_cycle == 1 ||
+      in_bitmap || crash_mode)) {
+
+    SAYF(bV bSTOP "   last new path : " cRST "%-34s ",
+         DTD(cur_ms, last_path_time));
+
+  } else {
+
+    if (dumb_mode)
+
+      SAYF(bV bSTOP "   last new path : " cPIN "n/a" cRST 
+           " (non-instrumented mode)        ");
+
+     else
+
+      SAYF(bV bSTOP "   last new path : " cRST "none yet " cLRD
+           "(odd, check syntax!)      ");
+
+  }
+
+  SAYF(bSTG bV bSTOP "  total paths : " cRST "%-5s  " bSTG bV "\n",
+       DI(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(unique_crashes),
+          (unique_crashes >= KEEP_UNIQUE_CRASH) ? "+" : "");
+
+  SAYF(bV bSTOP " last uniq crash : " cRST "%-34s " bSTG bV bSTOP
+       " uniq crashes : %s%-6s " bSTG bV "\n",
+       DTD(cur_ms, last_crash_time), unique_crashes ? cLRD : cRST,
+       tmp);
+
+  sprintf(tmp, "%s%s", DI(unique_hangs),
+         (unique_hangs >= KEEP_UNIQUE_HANG) ? "+" : "");
+
+  SAYF(bV bSTOP "  last uniq hang : " cRST "%-34s " bSTG bV bSTOP 
+       "   uniq hangs : " cRST "%-6s " bSTG bV "\n",
+       DTD(cur_ms, last_hang_time), tmp);
+
+  SAYF(bVR bH bSTOP cCYA " cycle progress " bSTG bH20 bHB bH bSTOP cCYA
+       " map coverage " bSTG bH bHT bH20 bH2 bH bVL "\n");
+
+  /* This gets funny because we want to print several variable-length variables
+     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 (%0.02f%%)", DI(current_entry),
+          queue_cur->favored ? "" : "*",
+          ((double)current_entry * 100) / queued_paths);
+
+  SAYF(bV bSTOP "  now processing : " cRST "%-17s " bSTG bV bSTOP, tmp);
+
+
+  sprintf(tmp, "%s (%0.02f%%)", DI(t_bytes), t_byte_ratio);
+
+  SAYF("    map density : %s%-21s " bSTG bV "\n", t_byte_ratio > 70 ? cLRD : 
+       ((t_bytes < 200 && !dumb_mode) ? cPIN : cRST), tmp);
+
+  sprintf(tmp, "%s (%0.02f%%)", DI(cur_skipped_paths),
+          ((double)cur_skipped_paths * 100) / queued_paths);
+
+  SAYF(bV bSTOP " paths timed out : " cRST "%-17s " bSTG bV, tmp);
+
+  sprintf(tmp, "%0.02f bits/tuple",
+          t_bytes ? (((double)t_bits) / t_bytes) : 0);
+
+  SAYF(bSTOP " count coverage : " cRST "%-21s " bSTG bV "\n", tmp);
+
+  SAYF(bVR bH bSTOP cCYA " stage progress " bSTG bH20 bX bH bSTOP cCYA
+       " findings in depth " bSTG bH20 bVL "\n");
+
+  sprintf(tmp, "%s (%0.02f%%)", DI(queued_favored),
+          ((double)queued_favored) * 100 / queued_paths);
+
+  /* Yeah... it's still going on... halp? */
+
+  SAYF(bV bSTOP "  now trying : " cRST "%-21s " bSTG bV bSTOP 
+       " favored paths : " cRST "%-22s " bSTG bV "\n", stage_name, tmp);
+
+  if (!stage_max) {
+
+    sprintf(tmp, "%s/-", DI(stage_cur));
+
+  } else {
+
+    sprintf(tmp, "%s/%s (%0.02f%%)", DI(stage_cur), DI(stage_max),
+            ((double)stage_cur) * 100 / stage_max);
+
+  }
+
+  SAYF(bV bSTOP " stage execs : " cRST "%-21s " bSTG bV bSTOP, tmp);
+
+  sprintf(tmp, "%s (%0.02f%%)", DI(queued_with_cov),
+          ((double)queued_with_cov) * 100 / queued_paths);
+
+  SAYF("  new edges on : " cRST "%-22s " bSTG bV "\n", tmp);
+
+  sprintf(tmp, "%s (%s%s unique)", DI(total_crashes), DI(unique_crashes),
+          (unique_crashes >= KEEP_UNIQUE_CRASH) ? "+" : "");
+
+  if (crash_mode) {
+
+    SAYF(bV bSTOP " total execs : " cRST "%-21s " bSTG bV bSTOP
+         "   new crashes : %s%-22s " bSTG bV "\n", DI(total_execs),
+         unique_crashes ? cLRD : cRST, tmp);
+
+  } else {
+
+    SAYF(bV bSTOP " total execs : " cRST "%-21s " bSTG bV bSTOP
+         " total crashes : %s%-22s " bSTG bV "\n", DI(total_execs),
+         unique_crashes ? cLRD : cRST, tmp);
+
+  }
+
+  /* Show a warning about slow execution. */
+
+  if (avg_exec < 100) {
+
+    sprintf(tmp, "%s/sec (%s)", DF(avg_exec), avg_exec < 20 ?
+            "zzzz..." : "slow!");
+
+    SAYF(bV bSTOP "  exec speed : " cLRD "%-21s ", tmp);
+
+  } else {
+
+    sprintf(tmp, "%s/sec", DF(avg_exec));
+    SAYF(bV bSTOP "  exec speed : " cRST "%-21s ", tmp);
+
+  }
+
+  sprintf(tmp, "%s (%s%s unique)", DI(total_hangs), DI(unique_hangs),
+          (unique_hangs >= KEEP_UNIQUE_HANG) ? "+" : "");
+
+  SAYF (bSTG bV bSTOP "   total hangs : " cRST "%-22s " bSTG bV "\n", tmp);
+
+  /* Aaaalmost there... hold on! */
+
+  SAYF(bVR bH cCYA bSTOP " fuzzing strategy yields " bSTG bH10 bH bHT bH10
+       bH5 bHB bH bSTOP cCYA " path geometry " bSTG bH5 bH2 bH bVL "\n");
+
+  if (skip_deterministic) {
+
+    strcpy(tmp, "n/a, n/a, n/a");
+
+  } else {
+
+    sprintf(tmp, "%s/%s, %s/%s, %s/%s",
+            DI(stage_finds[STAGE_FLIP1]), DI(stage_cycles[STAGE_FLIP1]),
+            DI(stage_finds[STAGE_FLIP2]), DI(stage_cycles[STAGE_FLIP2]),
+            DI(stage_finds[STAGE_FLIP4]), DI(stage_cycles[STAGE_FLIP4]));
+
+  }
+
+  SAYF(bV bSTOP "   bit flips : " cRST "%-37s " bSTG bV bSTOP "    levels : "
+       cRST "%-10s " bSTG bV "\n", tmp, DI(max_depth));
+
+  if (!skip_deterministic)
+    sprintf(tmp, "%s/%s, %s/%s, %s/%s",
+            DI(stage_finds[STAGE_FLIP8]), DI(stage_cycles[STAGE_FLIP8]),
+            DI(stage_finds[STAGE_FLIP16]), DI(stage_cycles[STAGE_FLIP16]),
+            DI(stage_finds[STAGE_FLIP32]), DI(stage_cycles[STAGE_FLIP32]));
+
+  SAYF(bV bSTOP "  byte flips : " cRST "%-37s " bSTG bV bSTOP "   pending : "
+       cRST "%-10s " bSTG bV "\n", tmp, DI(pending_not_fuzzed));
+
+  if (!skip_deterministic)
+    sprintf(tmp, "%s/%s, %s/%s, %s/%s",
+            DI(stage_finds[STAGE_ARITH8]), DI(stage_cycles[STAGE_ARITH8]),
+            DI(stage_finds[STAGE_ARITH16]), DI(stage_cycles[STAGE_ARITH16]),
+            DI(stage_finds[STAGE_ARITH32]), DI(stage_cycles[STAGE_ARITH32]));
+
+  SAYF(bV bSTOP " arithmetics : " cRST "%-37s " bSTG bV bSTOP "  pend fav : "
+       cRST "%-10s " bSTG bV "\n", tmp, DI(pending_favored));
+
+  if (!skip_deterministic)
+    sprintf(tmp, "%s/%s, %s/%s, %s/%s",
+            DI(stage_finds[STAGE_INTEREST8]), DI(stage_cycles[STAGE_INTEREST8]),
+            DI(stage_finds[STAGE_INTEREST16]), DI(stage_cycles[STAGE_INTEREST16]),
+            DI(stage_finds[STAGE_INTEREST32]), DI(stage_cycles[STAGE_INTEREST32]));
+
+  SAYF(bV bSTOP "  known ints : " cRST "%-37s " bSTG bV bSTOP " own finds : "
+       cRST "%-10s " bSTG bV "\n", tmp, DI(queued_discovered));
+
+  if (!skip_deterministic)
+    sprintf(tmp, "%s/%s, %s/%s, %s/%s",
+            DI(stage_finds[STAGE_EXTRAS_UO]), DI(stage_cycles[STAGE_EXTRAS_UO]),
+            DI(stage_finds[STAGE_EXTRAS_UI]), DI(stage_cycles[STAGE_EXTRAS_UI]),
+            DI(stage_finds[STAGE_EXTRAS_AO]), DI(stage_cycles[STAGE_EXTRAS_AO]));
+
+  SAYF(bV bSTOP "  dictionary : " cRST "%-37s " bSTG bV bSTOP
+       "  imported : " cRST "%-10s " bSTG bV "\n", tmp,
+       sync_id ? DI(queued_imported) : (u8*)"n/a");
+
+  sprintf(tmp, "%s/%s, %s/%s",
+          DI(stage_finds[STAGE_HAVOC]), DI(stage_cycles[STAGE_HAVOC]),
+          DI(stage_finds[STAGE_SPLICE]), DI(stage_cycles[STAGE_SPLICE]));
+
+  SAYF(bV bSTOP "       havoc : " cRST "%-37s " bSTG bV bSTOP 
+       "  variable : %s%-10s " bSTG bV "\n", tmp, queued_variable ? cLRD : cRST,
+      no_var_check ? (u8*)"n/a" : DI(queued_variable));
+
+  if (!bytes_trim_out) {
+
+    sprintf(tmp, "n/a, ");
+
+  } else {
+
+    sprintf(tmp, "%0.02f%%/%s, ",
+            ((double)(bytes_trim_in - bytes_trim_out)) * 100 / bytes_trim_in,
+            DI(trim_execs));
+
+  }
+
+  if (!blocks_eff_total) {
+
+    u8 tmp2[128];
+
+    sprintf(tmp2, "n/a");
+    strcat(tmp, tmp2);
+
+  } else {
+
+    u8 tmp2[128];
+
+    sprintf(tmp2, "%0.02f%%",
+            ((double)(blocks_eff_total - blocks_eff_select)) * 100 /
+            blocks_eff_total);
+
+    strcat(tmp, tmp2);
+
+  }
+
+  SAYF(bV bSTOP "        trim : " cRST "%-37s " bSTG bVR bH20 bH2 bH2 bRB "\n"
+       bLB bH30 bH20 bH2 bH bRB bSTOP cRST RESET_G1, tmp);
+
+  /* Provide some CPU utilization stats. */
+
+  if (cpu_core_count) {
+
+    double cur_runnable = get_runnable_processes();
+    u32 cur_utilization = cur_runnable * 100 / cpu_core_count;
+
+    u8* cpu_color = cCYA;
+
+    /* If we could still run one or more processes, use green. */
+
+    if (cpu_core_count > 1 && cur_runnable + 1 <= cpu_core_count)
+      cpu_color = cLGN;
+
+    /* If we're clearly oversubscribed, use red. */
+
+    if (!no_cpu_meter_red && cur_utilization >= 150) cpu_color = cLRD;
+
+#ifdef HAVE_AFFINITY
+
+    if (use_affinity) {
+
+      SAYF(SP10 cGRA "[cpu@%02u:%s%3u%%" cGRA "]\r" cRST, 
+           MIN(cpu_aff_child, 99), cpu_color,
+           MIN(cur_utilization, 999));
+
+    } else {
+
+      SAYF(SP10 cGRA "   [cpu:%s%3u%%" cGRA "]\r" cRST,
+           cpu_color, MIN(cur_utilization, 999));
+ 
+   }
+#else
+
+    SAYF(SP10 cGRA "   [cpu:%s%3u%%" cGRA "]\r" cRST,
+         cpu_color, MIN(cur_utilization, 999));
+
+#endif /* ^HAVE_AFFINITY */
+
+  } else SAYF("\r");
+
+  /* Hallelujah! */
+
+  fflush(0);
+
+}
+
+
+/* Display quick statistics at the end of processing the input directory,
+   plus a bunch of warnings. Some calibration stuff also ended up here,
+   along with several hardcoded constants. Maybe clean up eventually. */
+
+static void show_init_stats(void) {
+
+  struct queue_entry* q = queue;
+  u32 min_bits = 0, max_bits = 0;
+  u64 min_us = 0, max_us = 0;
+  u64 avg_us = 0;
+  u32 max_len = 0;
+
+  if (total_cal_cycles) avg_us = total_cal_us / total_cal_cycles;
+
+  while (q) {
+
+    if (!min_us || q->exec_us < min_us) min_us = q->exec_us;
+    if (q->exec_us > max_us) max_us = q->exec_us;
+
+    if (!min_bits || q->bitmap_size < min_bits) min_bits = q->bitmap_size;
+    if (q->bitmap_size > max_bits) max_bits = q->bitmap_size;
+
+    if (q->len > max_len) max_len = q->len;
+
+    q = q->next;
+
+  }
+
+  SAYF("\n");
+
+  if (avg_us > (qemu_mode ? 50000 : 10000)) 
+    WARNF(cLRD "The target binary is pretty slow! See %s/perf_tips.txt.",
+          doc_path);
+
+  /* Let's keep things moving with slow binaries. */
+
+  if (avg_us > 50000) havoc_div = 10;     /* 0-19 execs/sec   */
+  else if (avg_us > 20000) havoc_div = 5; /* 20-49 execs/sec  */
+  else if (avg_us > 10000) havoc_div = 2; /* 50-100 execs/sec */
+
+  if (!resuming_fuzz) {
+
+    if (max_len > 50 * 1024)
+      WARNF(cLRD "Some test cases are huge (%s) - see %s/perf_tips.txt!",
+            DMS(max_len), doc_path);
+    else if (max_len > 10 * 1024)
+      WARNF("Some test cases are big (%s) - see %s/perf_tips.txt.",
+            DMS(max_len), doc_path);
+
+    if (useless_at_start && !in_bitmap)
+      WARNF(cLRD "Some test cases look useless. Consider using a smaller set.");
+
+    if (queued_paths > 100)
+      WARNF(cLRD "You probably have far too many input files! Consider trimming down.");
+    else if (queued_paths > 20)
+      WARNF("You have lots of input files; try starting small.");
+
+  }
+
+  OKF("Here are some useful stats:\n\n"
+
+      cGRA "    Test case count : " cRST "%u favored, %u variable, %u total\n"
+      cGRA "       Bitmap range : " cRST "%u to %u bits (average: %0.02f bits)\n"
+      cGRA "        Exec timing : " cRST "%s to %s us (average: %s us)\n",
+      queued_favored, queued_variable, queued_paths, min_bits, max_bits, 
+      ((double)total_bitmap_size) / (total_bitmap_entries ? total_bitmap_entries : 1),
+      DI(min_us), DI(max_us), DI(avg_us));
+
+  if (!timeout_given) {
+
+    /* Figure out the appropriate timeout. The basic idea is: 5x average or
+       1x max, rounded up to EXEC_TM_ROUND ms and capped at 1 second.
+
+       If the program is slow, the multiplier is lowered to 2x or 3x, because
+       random scheduler jitter is less likely to have any impact, and because
+       our patience is wearing thin =) */
+
+    if (avg_us > 50000) exec_tmout = avg_us * 2 / 1000;
+    else if (avg_us > 10000) exec_tmout = avg_us * 3 / 1000;
+    else exec_tmout = avg_us * 5 / 1000;
+
+    exec_tmout = MAX(exec_tmout, max_us / 1000);
+    exec_tmout = (exec_tmout + EXEC_TM_ROUND) / EXEC_TM_ROUND * EXEC_TM_ROUND;
+
+    if (exec_tmout > EXEC_TIMEOUT) exec_tmout = EXEC_TIMEOUT;
+
+    ACTF("No -t option specified, so I'll use exec timeout of %u ms.", 
+         exec_tmout);
+
+    timeout_given = 1;
+
+  } else if (timeout_given == 3) {
+
+    ACTF("Applying timeout settings from resumed session (%u ms).", exec_tmout);
+
+  }
+
+  OKF("All set and ready to roll!");
+
+}
+
+
+/* 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;
+
+} 
+
+
+/* Trim all new test cases to save cycles when doing deterministic checks. The
+   trimmer uses power-of-two increments somewhere between 1/16 and 1/1024 of
+   file size, to keep the stage short and sweet. */
+
+static u8 trim_case(char** argv, 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 remove_len;
+  u32 len_p2;
+
+  /* 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;
+
+  stage_name = tmp;
+  bytes_trim_in += q->len;
+
+  /* Select initial chunk len, starting with large steps. */
+
+  len_p2 = next_p2(q->len);
+
+  remove_len = MAX(len_p2 / TRIM_START_STEPS, TRIM_MIN_BYTES);
+
+  /* Continue until the number of steps gets too high or the stepover
+     gets too small. */
+
+  while (remove_len >= MAX(len_p2 / TRIM_END_STEPS, TRIM_MIN_BYTES)) {
+
+    u32 remove_pos = remove_len;
+
+    sprintf(tmp, "trim %s/%s", DI(remove_len), DI(remove_len));
+
+    stage_cur = 0;
+    stage_max = q->len / remove_len;
+
+    while (remove_pos < q->len) {
+
+      u32 trim_avail = MIN(remove_len, q->len - remove_pos);
+      u32 cksum;
+
+      write_with_gap(in_buf, q->len, remove_pos, trim_avail);
+
+      fault = run_target(argv);
+      trim_execs++;
+
+      if (stop_soon || fault == FAULT_ERROR) goto abort_trimming;
+
+      /* Note that we don't keep track of crashes or hangs here; maybe TODO? */
+
+      cksum = hash32(trace_bits, 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
+         best-effort pass, so it's not a big deal if we end up with false
+         negatives every now and then. */
+
+      if (cksum == q->exec_cksum) {
+
+        u32 move_tail = q->len - remove_pos - trim_avail;
+
+        q->len -= trim_avail;
+        len_p2  = next_p2(q->len);
+
+        memmove(in_buf + remove_pos, in_buf + remove_pos + trim_avail, 
+                move_tail);
+
+        /* Let's save a clean trace, which will be needed by
+           update_bitmap_score once we're done with the trimming stuff. */
+
+        if (!needs_write) {
+
+          needs_write = 1;
+          memcpy(clean_trace, trace_bits, MAP_SIZE);
+
+        }
+
+      } else remove_pos += remove_len;
+
+      /* Since this can be slow, update the screen every now and then. */
+
+      if (!(trim_exec++ % stats_update_freq)) show_stats();
+      stage_cur++;
+
+    }
+
+    remove_len >>= 1;
+
+  }
+
+  /* If we have made changes to in_buf, we also need to update the on-disk
+     version of the test case. */
+
+  if (needs_write) {
+
+    s32 fd;
+
+    unlink(q->fname); /* ignore errors */
+
+    fd = open(q->fname, O_WRONLY | O_CREAT | O_EXCL, 0600);
+
+    if (fd < 0) PFATAL("Unable to create '%s'", q->fname);
+
+    ck_write(fd, in_buf, q->len, q->fname);
+    close(fd);
+
+    memcpy(trace_bits, clean_trace, MAP_SIZE);
+    update_bitmap_score(q);
+
+  }
+
+
+
+abort_trimming:
+
+  bytes_trim_out += q->len;
+  return fault;
+
+}
+
+
+/* Write a modified test case, run program, process results. Handle
+   error conditions, returning 1 if it's time to bail out. This is
+   a helper function for fuzz_one(). */
+
+EXP_ST u8 common_fuzz_stuff(char** argv, u8* out_buf, u32 len) {
+
+  u8 fault;
+
+  if (post_handler) {
+
+    out_buf = post_handler(out_buf, &len);
+    if (!out_buf || !len) return 0;
+
+  }
+
+  write_to_testcase(out_buf, len);
+
+  fault = run_target(argv);
+
+  if (stop_soon) return 1;
+
+  if (fault == FAULT_HANG) {
+
+    if (subseq_hangs++ > HANG_LIMIT) {
+      cur_skipped_paths++;
+      return 1;
+    }
+
+  } else subseq_hangs = 0;
+
+  /* Users can hit us with SIGUSR1 to request the current input
+     to be abandoned. */
+
+  if (skip_requested) {
+
+     skip_requested = 0;
+     cur_skipped_paths++;
+     return 1;
+
+  }
+
+  /* This handles FAULT_ERROR for us: */
+
+  queued_discovered += save_if_interesting(argv, out_buf, len, fault);
+
+  if (!(stage_cur % stats_update_freq) || stage_cur + 1 == stage_max)
+    show_stats();
+
+  return 0;
+
+}
+
+
+/* Helper to choose random block len for block operations in fuzz_one().
+   Doesn't return zero, provided that max_len is > 0. */
+
+static u32 choose_block_len(u32 limit) {
+
+  u32 min_value, max_value;
+  u32 rlim = MIN(queue_cycle, 3);
+
+  if (!run_over10m) rlim = 1;
+
+  switch (UR(rlim)) {
+
+    case 0:  min_value = 1;
+             max_value = HAVOC_BLK_SMALL;
+             break;
+
+    case 1:  min_value = HAVOC_BLK_SMALL;
+             max_value = HAVOC_BLK_MEDIUM;
+             break;
+
+    default: min_value = HAVOC_BLK_MEDIUM;
+             max_value = HAVOC_BLK_LARGE;
+
+
+  }
+
+  if (min_value >= limit) min_value = 1;
+
+  return min_value + UR(MIN(max_value, limit) - min_value + 1);
+
+}
+
+
+/* Calculate case desirability score to adjust the length of havoc fuzzing.
+   A helper function for fuzz_one(). Maybe some of these constants should
+   go into config.h. */
+
+static u32 calculate_score(struct queue_entry* q) {
+
+  u32 avg_exec_us = total_cal_us / total_cal_cycles;
+  u32 avg_bitmap_size = total_bitmap_size / total_bitmap_entries;
+  u32 perf_score = 100;
+
+  /* Adjust score based on execution speed of this path, compared to the
+     global average. Multiplier ranges from 0.1x to 3x. Fast inputs are
+     less expensive to fuzz, so we're giving them more air time. */
+
+  if (q->exec_us * 0.1 > avg_exec_us) perf_score = 10;
+  else if (q->exec_us * 0.25 > avg_exec_us) perf_score = 25;
+  else if (q->exec_us * 0.5 > avg_exec_us) perf_score = 50;
+  else if (q->exec_us * 0.75 > avg_exec_us) perf_score = 75;
+  else if (q->exec_us * 4 < avg_exec_us) perf_score = 300;
+  else if (q->exec_us * 3 < avg_exec_us) perf_score = 200;
+  else if (q->exec_us * 2 < avg_exec_us) perf_score = 150;
+
+  /* Adjust score based on bitmap size. The working theory is that better
+     coverage translates to better targets. Multiplier from 0.25x to 3x. */
+
+  if (q->bitmap_size * 0.3 > avg_bitmap_size) perf_score *= 3;
+  else if (q->bitmap_size * 0.5 > avg_bitmap_size) perf_score *= 2;
+  else if (q->bitmap_size * 0.75 > avg_bitmap_size) perf_score *= 1.5;
+  else if (q->bitmap_size * 3 < avg_bitmap_size) perf_score *= 0.25;
+  else if (q->bitmap_size * 2 < avg_bitmap_size) perf_score *= 0.5;
+  else if (q->bitmap_size * 1.5 < avg_bitmap_size) perf_score *= 0.75;
+
+  /* Adjust score based on handicap. Handicap is proportional to how late
+     in the game we learned about this path. Latecomers are allowed to run
+     for a bit longer until they catch up with the rest. */
+
+  if (q->handicap >= 4) {
+
+    perf_score *= 4;
+    q->handicap -= 4;
+
+  } else if (q->handicap) {
+
+    perf_score *= 2;
+    q->handicap--;
+
+  }
+
+  /* Final adjustment based on input depth, under the assumption that fuzzing
+     deeper test cases is more likely to reveal stuff that can't be
+     discovered with traditional fuzzers. */
+
+  switch (q->depth) {
+
+    case 0 ... 3:   break;
+    case 4 ... 7:   perf_score *= 2; break;
+    case 8 ... 13:  perf_score *= 4; break;
+    case 14 ... 25: perf_score *= 6; break;
+    default:        perf_score *= 8;
+
+  }
+
+  /* Make sure that we don't go over limit. */
+
+  if (perf_score > HAVOC_MAX_MULT * 100) perf_score = HAVOC_MAX_MULT * 100;
+
+  return perf_score;
+
+}
+
+
+/* Helper function to see if a particular change (xor_val = old ^ new) could
+   be a product of deterministic bit flips with the lengths and stepovers
+   attempted by afl-fuzz. This is used to avoid dupes in some of the
+   deterministic fuzzing operations that follow bit flips. We also
+   return 1 if xor_val is zero, which implies that the old and attempted new
+   values are identical and the exec would be a waste of time. */
+
+static u8 could_be_bitflip(u32 xor_val) {
+
+  u32 sh = 0;
+
+  if (!xor_val) return 1;
+
+  /* Shift left until first bit set. */
+
+  while (!(xor_val & 1)) { sh++; xor_val >>= 1; }
+
+  /* 1-, 2-, and 4-bit patterns are OK anywhere. */
+
+  if (xor_val == 1 || xor_val == 3 || xor_val == 15) return 1;
+
+  /* 8-, 16-, and 32-bit patterns are OK only if shift factor is
+     divisible by 8, since that's the stepover for these ops. */
+
+  if (sh & 7) return 0;
+
+  if (xor_val == 0xff || xor_val == 0xffff || xor_val == 0xffffffff)
+    return 1;
+
+  return 0;
+
+}
+
+
+/* Helper function to see if a particular value is reachable through
+   arithmetic operations. Used for similar purposes. */
+
+static u8 could_be_arith(u32 old_val, u32 new_val, u8 blen) {
+
+  u32 i, ov = 0, nv = 0, diffs = 0;
+
+  if (old_val == new_val) return 1;
+
+  /* See if one-byte adjustments to any byte could produce this result. */
+
+  for (i = 0; i < blen; i++) {
+
+    u8 a = old_val >> (8 * i),
+       b = new_val >> (8 * i);
+
+    if (a != b) { diffs++; ov = a; nv = b; }
+
+  }
+
+  /* If only one byte differs and the values are within range, return 1. */
+
+  if (diffs == 1) {
+
+    if ((u8)(ov - nv) <= ARITH_MAX ||
+        (u8)(nv - ov) <= ARITH_MAX) return 1;
+
+  }
+
+  if (blen == 1) return 0;
+
+  /* See if two-byte adjustments to any byte would produce this result. */
+
+  diffs = 0;
+
+  for (i = 0; i < blen / 2; i++) {
+
+    u16 a = old_val >> (16 * i),
+        b = new_val >> (16 * i);
+
+    if (a != b) { diffs++; ov = a; nv = b; }
+
+  }
+
+  /* If only one word differs and the values are within range, return 1. */
+
+  if (diffs == 1) {
+
+    if ((u16)(ov - nv) <= ARITH_MAX ||
+        (u16)(nv - ov) <= ARITH_MAX) return 1;
+
+    ov = SWAP16(ov); nv = SWAP16(nv);
+
+    if ((u16)(ov - nv) <= ARITH_MAX ||
+        (u16)(nv - ov) <= ARITH_MAX) return 1;
+
+  }
+
+  /* Finally, let's do the same thing for dwords. */
+
+  if (blen == 4) {
+
+    if ((u32)(old_val - new_val) <= ARITH_MAX ||
+        (u32)(new_val - old_val) <= ARITH_MAX) return 1;
+
+    new_val = SWAP32(new_val);
+    old_val = SWAP32(old_val);
+
+    if ((u32)(old_val - new_val) <= ARITH_MAX ||
+        (u32)(new_val - old_val) <= ARITH_MAX) return 1;
+
+  }
+
+  return 0;
+
+}
+
+
+/* Last but not least, a similar helper to see if insertion of an 
+   interesting integer is redundant given the insertions done for
+   shorter blen. The last param (check_le) is set if the caller
+   already executed LE insertion for current blen and wants to see
+   if BE variant passed in new_val is unique. */
+
+static u8 could_be_interest(u32 old_val, u32 new_val, u8 blen, u8 check_le) {
+
+  u32 i, j;
+
+  if (old_val == new_val) return 1;
+
+  /* See if one-byte insertions from interesting_8 over old_val could
+     produce new_val. */
+
+  for (i = 0; i < blen; i++) {
+
+    for (j = 0; j < sizeof(interesting_8); j++) {
+
+      u32 tval = (old_val & ~(0xff << (i * 8))) |
+                 (((u8)interesting_8[j]) << (i * 8));
+
+      if (new_val == tval) return 1;
+
+    }
+
+  }
+
+  /* Bail out unless we're also asked to examine two-byte LE insertions
+     as a preparation for BE attempts. */
+
+  if (blen == 2 && !check_le) return 0;
+
+  /* See if two-byte insertions over old_val could give us new_val. */
+
+  for (i = 0; i < blen - 1; i++) {
+
+    for (j = 0; j < sizeof(interesting_16) / 2; j++) {
+
+      u32 tval = (old_val & ~(0xffff << (i * 8))) |
+                 (((u16)interesting_16[j]) << (i * 8));
+
+      if (new_val == tval) return 1;
+
+      /* Continue here only if blen > 2. */
+
+      if (blen > 2) {
+
+        tval = (old_val & ~(0xffff << (i * 8))) |
+               (SWAP16(interesting_16[j]) << (i * 8));
+
+        if (new_val == tval) return 1;
+
+      }
+
+    }
+
+  }
+
+  if (blen == 4 && check_le) {
+
+    /* See if four-byte insertions could produce the same result
+       (LE only). */
+
+    for (j = 0; j < sizeof(interesting_32) / 4; j++)
+      if (new_val == (u32)interesting_32[j]) return 1;
+
+  }
+
+  return 0;
+
+}
+
+
+/* Take the current entry from the queue, fuzz it for a while. This
+   function is a tad too long... returns 0 if fuzzed successfully, 1 if
+   skipped or bailed out. */
+
+static u8 fuzz_one(char** argv) {
+
+  s32 len, fd, temp_len, i, j;
+  u8  *in_buf, *out_buf, *orig_in, *ex_tmp, *eff_map = 0;
+  u64 havoc_queued,  orig_hit_cnt, new_hit_cnt;
+  u32 splice_cycle = 0, perf_score = 100, orig_perf, prev_cksum, eff_cnt = 1;
+
+  u8  ret_val = 1;
+
+  u8  a_collect[MAX_AUTO_EXTRA];
+  u32 a_len = 0;
+
+#ifdef IGNORE_FINDS
+
+  /* In IGNORE_FINDS mode, skip any entries that weren't in the
+     initial data set. */
+
+  if (queue_cur->depth > 1) return 1;
+
+#else
+
+  if (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
+       cases. */
+
+    if ((queue_cur->was_fuzzed || !queue_cur->favored) &&
+        UR(100) < SKIP_TO_NEW_PROB) return 1;
+
+  } else if (!dumb_mode && !queue_cur->favored && queued_paths > 10) {
+
+    /* Otherwise, still possibly skip non-favored cases, albeit less often.
+       The odds of skipping stuff are higher for already-fuzzed inputs and
+       lower for never-fuzzed entries. */
+
+    if (queue_cycle > 1 && !queue_cur->was_fuzzed) {
+
+      if (UR(100) < SKIP_NFAV_NEW_PROB) return 1;
+
+    } else {
+
+      if (UR(100) < SKIP_NFAV_OLD_PROB) return 1;
+
+    }
+
+  }
+
+#endif /* ^IGNORE_FINDS */
+
+  if (not_on_tty)
+    ACTF("Fuzzing test case #%u (%u total)...", current_entry, queued_paths);
+
+  /* Map the test case into memory. */
+
+  fd = open(queue_cur->fname, O_RDONLY);
+
+  if (fd < 0) PFATAL("Unable to open '%s'", queue_cur->fname);
+
+  len = queue_cur->len;
+
+  orig_in = in_buf = mmap(0, len, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
+
+  if (orig_in == MAP_FAILED) PFATAL("Unable to mmap '%s'", queue_cur->fname);
+
+  close(fd);
+
+  /* We could mmap() out_buf as MAP_PRIVATE, but we end up clobbering every
+     single byte anyway, so it wouldn't give us any performance or memory usage
+     benefits. */
+
+  out_buf = ck_alloc_nozero(len);
+
+  subseq_hangs = 0;
+
+  cur_depth = queue_cur->depth;
+
+  /*******************************************
+   * CALIBRATION (only if failed earlier on) *
+   *******************************************/
+
+  if (queue_cur->cal_failed) {
+
+    u8 res = FAULT_HANG;
+
+    if (queue_cur->cal_failed < CAL_CHANCES) {
+
+      res = calibrate_case(argv, queue_cur, in_buf, queue_cycle - 1, 0);
+
+      if (res == FAULT_ERROR)
+        FATAL("Unable to execute target application");
+
+    }
+
+    if (stop_soon || res != crash_mode) {
+      cur_skipped_paths++;
+      goto abandon_entry;
+    }
+
+  }
+
+  /************
+   * TRIMMING *
+   ************/
+
+  if (!dumb_mode && !queue_cur->trim_done) {
+
+    u8 res = trim_case(argv, queue_cur, in_buf);
+
+    if (res == FAULT_ERROR)
+      FATAL("Unable to execute target application");
+
+    if (stop_soon) {
+      cur_skipped_paths++;
+      goto abandon_entry;
+    }
+
+    /* Don't retry trimming, even if it failed. */
+
+    queue_cur->trim_done = 1;
+
+    if (len != queue_cur->len) len = queue_cur->len;
+
+  }
+
+  memcpy(out_buf, in_buf, len);
+
+  /*********************
+   * PERFORMANCE SCORE *
+   *********************/
+
+  orig_perf = perf_score = calculate_score(queue_cur);
+
+  /* Skip right away if -d is given, if we have done deterministic fuzzing on
+     this entry ourselves (was_fuzzed), or if it has gone through deterministic
+     testing in earlier, resumed runs (passed_det). */
+
+  if (skip_deterministic || queue_cur->was_fuzzed || queue_cur->passed_det)
+    goto havoc_stage;
+
+  /*********************************************
+   * SIMPLE BITFLIP (+dictionary construction) *
+   *********************************************/
+
+#define FLIP_BIT(_ar, _b) do { \
+    u8* _arf = (u8*)(_ar); \
+    u32 _bf = (_b); \
+    _arf[(_bf) >> 3] ^= (128 >> ((_bf) & 7)); \
+  } while (0)
+
+  /* Single walking bit. */
+
+  stage_short = "flip1";
+  stage_max   = len << 3;
+  stage_name  = "bitflip 1/1";
+
+  stage_val_type = STAGE_VAL_NONE;
+
+  orig_hit_cnt = queued_paths + unique_crashes;
+
+  prev_cksum = queue_cur->exec_cksum;
+
+  for (stage_cur = 0; stage_cur < stage_max; stage_cur++) {
+
+    stage_cur_byte = stage_cur >> 3;
+
+    FLIP_BIT(out_buf, stage_cur);
+
+    if (common_fuzz_stuff(argv, out_buf, len)) goto abandon_entry;
+
+    FLIP_BIT(out_buf, stage_cur);
+
+    /* While flipping the least significant bit in every byte, pull of an extra
+       trick to detect possible syntax tokens. In essence, the idea is that if
+       you have a binary blob like this:
+
+       xxxxxxxxIHDRxxxxxxxx
+
+       ...and changing the leading and trailing bytes causes variable or no
+       changes in program flow, but touching any character in the "IHDR" string
+       always produces the same, distinctive path, it's highly likely that
+       "IHDR" is an atomically-checked magic value of special significance to
+       the fuzzed format.
+
+       We do this here, rather than as a separate stage, because it's a nice
+       way to keep the operation approximately "free" (i.e., no extra execs).
+       
+       Empirically, performing the check when flipping the least significant bit
+       is advantageous, compared to doing it at the time of more disruptive
+       changes, where the program flow may be affected in more violent ways.
+
+       The caveat is that we won't generate dictionaries in the -d mode or -S
+       mode - but that's probably a fair trade-off.
+
+       This won't work particularly well with paths that exhibit variable
+       behavior, but fails gracefully, so we'll carry out the checks anyway.
+
+      */
+
+    if (!dumb_mode && (stage_cur & 7) == 7) {
+
+      u32 cksum = hash32(trace_bits, MAP_SIZE, HASH_CONST);
+
+      if (stage_cur == stage_max - 1 && cksum == prev_cksum) {
+
+        /* If at end of file and we are still collecting a string, grab the
+           final character and force output. */
+
+        if (a_len < MAX_AUTO_EXTRA) a_collect[a_len] = out_buf[stage_cur >> 3];
+        a_len++;
+
+        if (a_len >= MIN_AUTO_EXTRA && a_len <= MAX_AUTO_EXTRA)
+          maybe_add_auto(a_collect, a_len);
+
+      } else if (cksum != prev_cksum) {
+
+        /* Otherwise, if the checksum has changed, see if we have something
+           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(a_collect, a_len);
+
+        a_len = 0;
+        prev_cksum = cksum;
+
+      }
+
+      /* Continue collecting string, but only if the bit flip actually made
+         any difference - we don't want no-op tokens. */
+
+      if (cksum != queue_cur->exec_cksum) {
+
+        if (a_len < MAX_AUTO_EXTRA) a_collect[a_len] = out_buf[stage_cur >> 3];        
+        a_len++;
+
+      }
+
+    }
+
+  }
+
+  new_hit_cnt = queued_paths + unique_crashes;
+
+  stage_finds[STAGE_FLIP1]  += new_hit_cnt - orig_hit_cnt;
+  stage_cycles[STAGE_FLIP1] += stage_max;
+
+  if (queue_cur->passed_det) goto havoc_stage;
+
+  /* Two walking bits. */
+
+  stage_name  = "bitflip 2/1";
+  stage_short = "flip2";
+  stage_max   = (len << 3) - 1;
+
+  orig_hit_cnt = new_hit_cnt;
+
+  for (stage_cur = 0; stage_cur < stage_max; stage_cur++) {
+
+    stage_cur_byte = stage_cur >> 3;
+
+    FLIP_BIT(out_buf, stage_cur);
+    FLIP_BIT(out_buf, stage_cur + 1);
+
+    if (common_fuzz_stuff(argv, out_buf, len)) goto abandon_entry;
+
+    FLIP_BIT(out_buf, stage_cur);
+    FLIP_BIT(out_buf, stage_cur + 1);
+
+  }
+
+  new_hit_cnt = queued_paths + unique_crashes;
+
+  stage_finds[STAGE_FLIP2]  += new_hit_cnt - orig_hit_cnt;
+  stage_cycles[STAGE_FLIP2] += stage_max;
+
+  /* Four walking bits. */
+
+  stage_name  = "bitflip 4/1";
+  stage_short = "flip4";
+  stage_max   = (len << 3) - 3;
+
+  orig_hit_cnt = new_hit_cnt;
+
+  for (stage_cur = 0; stage_cur < stage_max; stage_cur++) {
+
+    stage_cur_byte = stage_cur >> 3;
+
+    FLIP_BIT(out_buf, stage_cur);
+    FLIP_BIT(out_buf, stage_cur + 1);
+    FLIP_BIT(out_buf, stage_cur + 2);
+    FLIP_BIT(out_buf, stage_cur + 3);
+
+    if (common_fuzz_stuff(argv, out_buf, len)) goto abandon_entry;
+
+    FLIP_BIT(out_buf, stage_cur);
+    FLIP_BIT(out_buf, stage_cur + 1);
+    FLIP_BIT(out_buf, stage_cur + 2);
+    FLIP_BIT(out_buf, stage_cur + 3);
+
+  }
+
+  new_hit_cnt = queued_paths + unique_crashes;
+
+  stage_finds[STAGE_FLIP4]  += new_hit_cnt - orig_hit_cnt;
+  stage_cycles[STAGE_FLIP4] += stage_max;
+
+  /* Effector map setup. These macros calculate:
+
+     EFF_APOS      - position of a particular file offset in the map.
+     EFF_ALEN      - length of an map with a particular number of bytes.
+     EFF_SPAN_ALEN - map span for a sequence of bytes.
+
+   */
+
+#define EFF_APOS(_p)          ((_p) >> EFF_MAP_SCALE2)
+#define EFF_REM(_x)           ((_x) & ((1 << EFF_MAP_SCALE2) - 1))
+#define EFF_ALEN(_l)          (EFF_APOS(_l) + !!EFF_REM(_l))
+#define EFF_SPAN_ALEN(_p, _l) (EFF_APOS((_p) + (_l) - 1) - EFF_APOS(_p) + 1)
+
+  /* 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[0] = 1;
+
+  if (EFF_APOS(len - 1) != 0) {
+    eff_map[EFF_APOS(len - 1)] = 1;
+    eff_cnt++;
+  }
+
+  /* Walking byte. */
+
+  stage_name  = "bitflip 8/8";
+  stage_short = "flip8";
+  stage_max   = len;
+
+  orig_hit_cnt = new_hit_cnt;
+
+  for (stage_cur = 0; stage_cur < stage_max; stage_cur++) {
+
+    stage_cur_byte = stage_cur;
+
+    out_buf[stage_cur] ^= 0xFF;
+
+    if (common_fuzz_stuff(argv, out_buf, len)) goto abandon_entry;
+
+    /* We also use this stage to pull off a simple trick: we identify
+       bytes that seem to have no effect on the current execution path
+       even when fully flipped - and we skip them during more expensive
+       deterministic stages, such as arithmetics or known ints. */
+
+    if (!eff_map[EFF_APOS(stage_cur)]) {
+
+      u32 cksum;
+
+      /* If in dumb mode or if the file is very short, just flag everything
+         without wasting time on checksums. */
+
+      if (!dumb_mode && len >= EFF_MIN_LEN)
+        cksum = hash32(trace_bits, MAP_SIZE, HASH_CONST);
+      else
+        cksum = ~queue_cur->exec_cksum;
+
+      if (cksum != queue_cur->exec_cksum) {
+        eff_map[EFF_APOS(stage_cur)] = 1;
+        eff_cnt++;
+      }
+
+    }
+
+    out_buf[stage_cur] ^= 0xFF;
+
+  }
+
+  /* If the effector map is more than EFF_MAX_PERC dense, just flag the
+     whole thing as worth fuzzing, since we wouldn't be saving much time
+     anyway. */
+
+  if (eff_cnt != EFF_ALEN(len) &&
+      eff_cnt * 100 / EFF_ALEN(len) > EFF_MAX_PERC) {
+
+    memset(eff_map, 1, EFF_ALEN(len));
+
+    blocks_eff_select += EFF_ALEN(len);
+
+  } else {
+
+    blocks_eff_select += eff_cnt;
+
+  }
+
+  blocks_eff_total += EFF_ALEN(len);
+
+  new_hit_cnt = queued_paths + unique_crashes;
+
+  stage_finds[STAGE_FLIP8]  += new_hit_cnt - orig_hit_cnt;
+  stage_cycles[STAGE_FLIP8] += stage_max;
+
+  /* Two walking bytes. */
+
+  if (len < 2) goto skip_bitflip;
+
+  stage_name  = "bitflip 16/8";
+  stage_short = "flip16";
+  stage_cur   = 0;
+  stage_max   = len - 1;
+
+  orig_hit_cnt = new_hit_cnt;
+
+  for (i = 0; i < len - 1; i++) {
+
+    /* Let's consult the effector map... */
+
+    if (!eff_map[EFF_APOS(i)] && !eff_map[EFF_APOS(i + 1)]) {
+      stage_max--;
+      continue;
+    }
+
+    stage_cur_byte = i;
+
+    *(u16*)(out_buf + i) ^= 0xFFFF;
+
+    if (common_fuzz_stuff(argv, out_buf, len)) goto abandon_entry;
+    stage_cur++;
+
+    *(u16*)(out_buf + i) ^= 0xFFFF;
+
+
+  }
+
+  new_hit_cnt = queued_paths + unique_crashes;
+
+  stage_finds[STAGE_FLIP16]  += new_hit_cnt - orig_hit_cnt;
+  stage_cycles[STAGE_FLIP16] += stage_max;
+
+  if (len < 4) goto skip_bitflip;
+
+  /* Four walking bytes. */
+
+  stage_name  = "bitflip 32/8";
+  stage_short = "flip32";
+  stage_cur   = 0;
+  stage_max   = len - 3;
+
+  orig_hit_cnt = new_hit_cnt;
+
+  for (i = 0; i < len - 3; i++) {
+
+    /* Let's consult the effector map... */
+    if (!eff_map[EFF_APOS(i)] && !eff_map[EFF_APOS(i + 1)] &&
+        !eff_map[EFF_APOS(i + 2)] && !eff_map[EFF_APOS(i + 3)]) {
+      stage_max--;
+      continue;
+    }
+
+    stage_cur_byte = i;
+
+    *(u32*)(out_buf + i) ^= 0xFFFFFFFF;
+
+    if (common_fuzz_stuff(argv, out_buf, len)) goto abandon_entry;
+    stage_cur++;
+
+    *(u32*)(out_buf + i) ^= 0xFFFFFFFF;
+
+  }
+
+  new_hit_cnt = queued_paths + unique_crashes;
+
+  stage_finds[STAGE_FLIP32]  += new_hit_cnt - orig_hit_cnt;
+  stage_cycles[STAGE_FLIP32] += stage_max;
+
+skip_bitflip:
+
+  /**********************
+   * ARITHMETIC INC/DEC *
+   **********************/
+
+  /* 8-bit arithmetics. */
+
+  stage_name  = "arith 8/8";
+  stage_short = "arith8";
+  stage_cur   = 0;
+  stage_max   = 2 * len * ARITH_MAX;
+
+  stage_val_type = STAGE_VAL_LE;
+
+  orig_hit_cnt = new_hit_cnt;
+
+  for (i = 0; i < len; i++) {
+
+    u8 orig = out_buf[i];
+
+    /* Let's consult the effector map... */
+
+    if (!eff_map[EFF_APOS(i)]) {
+      stage_max -= 2 * ARITH_MAX;
+      continue;
+    }
+
+    stage_cur_byte = i;
+
+    for (j = 1; j <= ARITH_MAX; j++) {
+
+      u8 r = orig ^ (orig + j);
+
+      /* Do arithmetic operations only if the result couldn't be a product
+         of a bitflip. */
+
+      if (!could_be_bitflip(r)) {
+
+        stage_cur_val = j;
+        out_buf[i] = orig + j;
+
+        if (common_fuzz_stuff(argv, out_buf, len)) goto abandon_entry;
+        stage_cur++;
+
+      } else stage_max--;
+
+      r =  orig ^ (orig - j);
+
+      if (!could_be_bitflip(r)) {
+
+        stage_cur_val = -j;
+        out_buf[i] = orig - j;
+
+        if (common_fuzz_stuff(argv, out_buf, len)) goto abandon_entry;
+        stage_cur++;
+
+      } else stage_max--;
+
+      out_buf[i] = orig;
+
+    }
+
+  }
+
+  new_hit_cnt = queued_paths + unique_crashes;
+
+  stage_finds[STAGE_ARITH8]  += new_hit_cnt - orig_hit_cnt;
+  stage_cycles[STAGE_ARITH8] += stage_max;
+
+  /* 16-bit arithmetics, both endians. */
+
+  if (len < 2) goto skip_arith;
+
+  stage_name  = "arith 16/8";
+  stage_short = "arith16";
+  stage_cur   = 0;
+  stage_max   = 4 * (len - 1) * ARITH_MAX;
+
+  orig_hit_cnt = new_hit_cnt;
+
+  for (i = 0; i < len - 1; i++) {
+
+    u16 orig = *(u16*)(out_buf + i);
+
+    /* Let's consult the effector map... */
+
+    if (!eff_map[EFF_APOS(i)] && !eff_map[EFF_APOS(i + 1)]) {
+      stage_max -= 4 * ARITH_MAX;
+      continue;
+    }
+
+    stage_cur_byte = i;
+
+    for (j = 1; j <= ARITH_MAX; j++) {
+
+      u16 r1 = orig ^ (orig + j),
+          r2 = orig ^ (orig - j),
+          r3 = orig ^ SWAP16(SWAP16(orig) + j),
+          r4 = orig ^ SWAP16(SWAP16(orig) - j);
+
+      /* Try little endian addition and subtraction first. Do it only
+         if the operation would affect more than one byte (hence the 
+         & 0xff overflow checks) and if it couldn't be a product of
+         a bitflip. */
+
+      stage_val_type = STAGE_VAL_LE; 
+
+      if ((orig & 0xff) + j > 0xff && !could_be_bitflip(r1)) {
+
+        stage_cur_val = j;
+        *(u16*)(out_buf + i) = orig + j;
+
+        if (common_fuzz_stuff(argv, out_buf, len)) goto abandon_entry;
+        stage_cur++;
+ 
+      } else stage_max--;
+
+      if ((orig & 0xff) < j && !could_be_bitflip(r2)) {
+
+        stage_cur_val = -j;
+        *(u16*)(out_buf + i) = orig - j;
+
+        if (common_fuzz_stuff(argv, out_buf, len)) goto abandon_entry;
+        stage_cur++;
+
+      } else stage_max--;
+
+      /* Big endian comes next. Same deal. */
+
+      stage_val_type = STAGE_VAL_BE;
+
+
+      if ((orig >> 8) + j > 0xff && !could_be_bitflip(r3)) {
+
+        stage_cur_val = j;
+        *(u16*)(out_buf + i) = SWAP16(SWAP16(orig) + j);
+
+        if (common_fuzz_stuff(argv, out_buf, len)) goto abandon_entry;
+        stage_cur++;
+
+      } else stage_max--;
+
+      if ((orig >> 8) < j && !could_be_bitflip(r4)) {
+
+        stage_cur_val = -j;
+        *(u16*)(out_buf + i) = SWAP16(SWAP16(orig) - j);
+
+        if (common_fuzz_stuff(argv, out_buf, len)) goto abandon_entry;
+        stage_cur++;
+
+      } else stage_max--;
+
+      *(u16*)(out_buf + i) = orig;
+
+    }
+
+  }
+
+  new_hit_cnt = queued_paths + unique_crashes;
+
+  stage_finds[STAGE_ARITH16]  += new_hit_cnt - orig_hit_cnt;
+  stage_cycles[STAGE_ARITH16] += stage_max;
+
+  /* 32-bit arithmetics, both endians. */
+
+  if (len < 4) goto skip_arith;
+
+  stage_name  = "arith 32/8";
+  stage_short = "arith32";
+  stage_cur   = 0;
+  stage_max   = 4 * (len - 3) * ARITH_MAX;
+
+  orig_hit_cnt = new_hit_cnt;
+
+  for (i = 0; i < len - 3; i++) {
+
+    u32 orig = *(u32*)(out_buf + i);
+
+    /* Let's consult the effector map... */
+
+    if (!eff_map[EFF_APOS(i)] && !eff_map[EFF_APOS(i + 1)] &&
+        !eff_map[EFF_APOS(i + 2)] && !eff_map[EFF_APOS(i + 3)]) {
+      stage_max -= 4 * ARITH_MAX;
+      continue;
+    }
+
+    stage_cur_byte = i;
+
+    for (j = 1; j <= ARITH_MAX; j++) {
+
+      u32 r1 = orig ^ (orig + j),
+          r2 = orig ^ (orig - j),
+          r3 = orig ^ SWAP32(SWAP32(orig) + j),
+          r4 = orig ^ SWAP32(SWAP32(orig) - j);
+
+      /* Little endian first. Same deal as with 16-bit: we only want to
+         try if the operation would have effect on more than two bytes. */
+
+      stage_val_type = STAGE_VAL_LE; 
+
+      if ((orig & 0xffff) + j > 0xffff && !could_be_bitflip(r1)) {
+
+        stage_cur_val = j;
+        *(u32*)(out_buf + i) = orig + j;
+
+        if (common_fuzz_stuff(argv, out_buf, len)) goto abandon_entry;
+        stage_cur++;
+
+      } else stage_max--;
+
+      if ((orig & 0xffff) < j && !could_be_bitflip(r2)) {
+
+        stage_cur_val = -j;
+        *(u32*)(out_buf + i) = orig - j;
+
+        if (common_fuzz_stuff(argv, out_buf, len)) goto abandon_entry;
+        stage_cur++;
+
+      } else stage_max--;
+
+      /* Big endian next. */
+
+      stage_val_type = STAGE_VAL_BE;
+
+      if ((SWAP32(orig) & 0xffff) + j > 0xffff && !could_be_bitflip(r3)) {
+
+        stage_cur_val = j;
+        *(u32*)(out_buf + i) = SWAP32(SWAP32(orig) + j);
+
+        if (common_fuzz_stuff(argv, out_buf, len)) goto abandon_entry;
+        stage_cur++;
+
+      } else stage_max--;
+
+      if ((SWAP32(orig) & 0xffff) < j && !could_be_bitflip(r4)) {
+
+        stage_cur_val = -j;
+        *(u32*)(out_buf + i) = SWAP32(SWAP32(orig) - j);
+
+        if (common_fuzz_stuff(argv, out_buf, len)) goto abandon_entry;
+        stage_cur++;
+
+      } else stage_max--;
+
+      *(u32*)(out_buf + i) = orig;
+
+    }
+
+  }
+
+  new_hit_cnt = queued_paths + unique_crashes;
+
+  stage_finds[STAGE_ARITH32]  += new_hit_cnt - orig_hit_cnt;
+  stage_cycles[STAGE_ARITH32] += stage_max;
+
+skip_arith:
+
+  /**********************
+   * INTERESTING VALUES *
+   **********************/
+
+  stage_name  = "interest 8/8";
+  stage_short = "int8";
+  stage_cur   = 0;
+  stage_max   = len * sizeof(interesting_8);
+
+  stage_val_type = STAGE_VAL_LE;
+
+  orig_hit_cnt = new_hit_cnt;
+
+  /* Setting 8-bit integers. */
+
+  for (i = 0; i < len; i++) {
+
+    u8 orig = out_buf[i];
+
+    /* Let's consult the effector map... */
+
+    if (!eff_map[EFF_APOS(i)]) {
+      stage_max -= sizeof(interesting_8);
+      continue;
+    }
+
+    stage_cur_byte = i;
+
+    for (j = 0; j < sizeof(interesting_8); j++) {
+
+      /* Skip if the value could be a product of bitflips or arithmetics. */
+
+      if (could_be_bitflip(orig ^ (u8)interesting_8[j]) ||
+          could_be_arith(orig, (u8)interesting_8[j], 1)) {
+        stage_max--;
+        continue;
+      }
+
+      stage_cur_val = interesting_8[j];
+      out_buf[i] = interesting_8[j];
+
+      if (common_fuzz_stuff(argv, out_buf, len)) goto abandon_entry;
+
+      out_buf[i] = orig;
+      stage_cur++;
+
+    }
+
+  }
+
+  new_hit_cnt = queued_paths + unique_crashes;
+
+  stage_finds[STAGE_INTEREST8]  += new_hit_cnt - orig_hit_cnt;
+  stage_cycles[STAGE_INTEREST8] += stage_max;
+
+  /* Setting 16-bit integers, both endians. */
+
+  if (len < 2) goto skip_interest;
+
+  stage_name  = "interest 16/8";
+  stage_short = "int16";
+  stage_cur   = 0;
+  stage_max   = 2 * (len - 1) * (sizeof(interesting_16) >> 1);
+
+  orig_hit_cnt = new_hit_cnt;
+
+  for (i = 0; i < len - 1; i++) {
+
+    u16 orig = *(u16*)(out_buf + i);
+
+    /* Let's consult the effector map... */
+
+    if (!eff_map[EFF_APOS(i)] && !eff_map[EFF_APOS(i + 1)]) {
+      stage_max -= sizeof(interesting_16);
+      continue;
+    }
+
+    stage_cur_byte = i;
+
+    for (j = 0; j < sizeof(interesting_16) / 2; j++) {
+
+      stage_cur_val = interesting_16[j];
+
+      /* Skip if this could be a product of a bitflip, arithmetics,
+         or single-byte interesting value insertion. */
+
+      if (!could_be_bitflip(orig ^ (u16)interesting_16[j]) &&
+          !could_be_arith(orig, (u16)interesting_16[j], 2) &&
+          !could_be_interest(orig, (u16)interesting_16[j], 2, 0)) {
+
+        stage_val_type = STAGE_VAL_LE;
+
+        *(u16*)(out_buf + i) = interesting_16[j];
+
+        if (common_fuzz_stuff(argv, out_buf, len)) goto abandon_entry;
+        stage_cur++;
+
+      } else stage_max--;
+
+      if ((u16)interesting_16[j] != SWAP16(interesting_16[j]) &&
+          !could_be_bitflip(orig ^ SWAP16(interesting_16[j])) &&
+          !could_be_arith(orig, SWAP16(interesting_16[j]), 2) &&
+          !could_be_interest(orig, SWAP16(interesting_16[j]), 2, 1)) {
+
+        stage_val_type = STAGE_VAL_BE;
+
+        *(u16*)(out_buf + i) = SWAP16(interesting_16[j]);
+        if (common_fuzz_stuff(argv, out_buf, len)) goto abandon_entry;
+        stage_cur++;
+
+      } else stage_max--;
+
+    }
+
+    *(u16*)(out_buf + i) = orig;
+
+  }
+
+  new_hit_cnt = queued_paths + unique_crashes;
+
+  stage_finds[STAGE_INTEREST16]  += new_hit_cnt - orig_hit_cnt;
+  stage_cycles[STAGE_INTEREST16] += stage_max;
+
+  if (len < 4) goto skip_interest;
+
+  /* Setting 32-bit integers, both endians. */
+
+  stage_name  = "interest 32/8";
+  stage_short = "int32";
+  stage_cur   = 0;
+  stage_max   = 2 * (len - 3) * (sizeof(interesting_32) >> 2);
+
+  orig_hit_cnt = new_hit_cnt;
+
+  for (i = 0; i < len - 3; i++) {
+
+    u32 orig = *(u32*)(out_buf + i);
+
+    /* Let's consult the effector map... */
+
+    if (!eff_map[EFF_APOS(i)] && !eff_map[EFF_APOS(i + 1)] &&
+        !eff_map[EFF_APOS(i + 2)] && !eff_map[EFF_APOS(i + 3)]) {
+      stage_max -= sizeof(interesting_32) >> 1;
+      continue;
+    }
+
+    stage_cur_byte = i;
+
+    for (j = 0; j < sizeof(interesting_32) / 4; j++) {
+
+      stage_cur_val = interesting_32[j];
+
+      /* Skip if this could be a product of a bitflip, arithmetics,
+         or word interesting value insertion. */
+
+      if (!could_be_bitflip(orig ^ (u32)interesting_32[j]) &&
+          !could_be_arith(orig, interesting_32[j], 4) &&
+          !could_be_interest(orig, interesting_32[j], 4, 0)) {
+
+        stage_val_type = STAGE_VAL_LE;
+
+        *(u32*)(out_buf + i) = interesting_32[j];
+
+        if (common_fuzz_stuff(argv, out_buf, len)) goto abandon_entry;
+        stage_cur++;
+
+      } else stage_max--;
+
+      if ((u32)interesting_32[j] != SWAP32(interesting_32[j]) &&
+          !could_be_bitflip(orig ^ SWAP32(interesting_32[j])) &&
+          !could_be_arith(orig, SWAP32(interesting_32[j]), 4) &&
+          !could_be_interest(orig, SWAP32(interesting_32[j]), 4, 1)) {
+
+        stage_val_type = STAGE_VAL_BE;
+
+        *(u32*)(out_buf + i) = SWAP32(interesting_32[j]);
+        if (common_fuzz_stuff(argv, out_buf, len)) goto abandon_entry;
+        stage_cur++;
+
+      } else stage_max--;
+
+    }
+
+    *(u32*)(out_buf + i) = orig;
+
+  }
+
+  new_hit_cnt = queued_paths + unique_crashes;
+
+  stage_finds[STAGE_INTEREST32]  += new_hit_cnt - orig_hit_cnt;
+  stage_cycles[STAGE_INTEREST32] += stage_max;
+
+skip_interest:
+
+  /********************
+   * DICTIONARY STUFF *
+   ********************/
+
+  if (!extras_cnt) goto skip_user_extras;
+
+  /* Overwrite with user-supplied extras. */
+
+  stage_name  = "user extras (over)";
+  stage_short = "ext_UO";
+  stage_cur   = 0;
+  stage_max   = extras_cnt * len;
+
+  stage_val_type = STAGE_VAL_NONE;
+
+  orig_hit_cnt = new_hit_cnt;
+
+  for (i = 0; i < len; i++) {
+
+    u32 last_len = 0;
+
+    stage_cur_byte = i;
+
+    /* Extras are sorted by size, from smallest to largest. This means
+       that we don't have to worry about restoring the buffer in
+       between writes at a particular offset determined by the outer
+       loop. */
+
+    for (j = 0; j < extras_cnt; j++) {
+
+      /* Skip extras probabilistically if extras_cnt > MAX_DET_EXTRAS. Also
+         skip them if there's no room to insert the payload, if the token
+         is redundant, or if its entire span has no bytes set in the effector
+         map. */
+
+      if ((extras_cnt > MAX_DET_EXTRAS && UR(extras_cnt) >= MAX_DET_EXTRAS) ||
+          extras[j].len > len - i ||
+          !memcmp(extras[j].data, out_buf + i, extras[j].len) ||
+          !memchr(eff_map + EFF_APOS(i), 1, EFF_SPAN_ALEN(i, extras[j].len))) {
+
+        stage_max--;
+        continue;
+
+      }
+
+      last_len = extras[j].len;
+      memcpy(out_buf + i, extras[j].data, last_len);
+
+      if (common_fuzz_stuff(argv, out_buf, len)) goto abandon_entry;
+
+      stage_cur++;
+
+    }
+
+    /* Restore all the clobbered memory. */
+    memcpy(out_buf + i, in_buf + i, last_len);
+
+  }
+
+  new_hit_cnt = queued_paths + unique_crashes;
+
+  stage_finds[STAGE_EXTRAS_UO]  += new_hit_cnt - orig_hit_cnt;
+  stage_cycles[STAGE_EXTRAS_UO] += stage_max;
+
+  /* Insertion of user-supplied extras. */
+
+  stage_name  = "user extras (insert)";
+  stage_short = "ext_UI";
+  stage_cur   = 0;
+  stage_max   = extras_cnt * len;
+
+  orig_hit_cnt = new_hit_cnt;
+
+  ex_tmp = ck_alloc(len + MAX_DICT_FILE);
+
+  for (i = 0; i < len; i++) {
+
+    stage_cur_byte = i;
+
+    for (j = 0; j < extras_cnt; j++) {
+
+      if (len + extras[j].len > MAX_FILE) {
+        stage_max--; 
+        continue;
+      }
+
+      /* Insert token */
+      memcpy(ex_tmp + i, extras[j].data, extras[j].len);
+
+      /* Copy tail */
+      memcpy(ex_tmp + i + extras[j].len, out_buf + i, len - i);
+
+      if (common_fuzz_stuff(argv, ex_tmp, len + extras[j].len)) {
+        ck_free(ex_tmp);
+        goto abandon_entry;
+      }
+
+      stage_cur++;
+
+    }
+
+    /* Copy head */
+    ex_tmp[i] = out_buf[i];
+
+  }
+
+  ck_free(ex_tmp);
+
+  new_hit_cnt = queued_paths + unique_crashes;
+
+  stage_finds[STAGE_EXTRAS_UI]  += new_hit_cnt - orig_hit_cnt;
+  stage_cycles[STAGE_EXTRAS_UI] += stage_max;
+
+skip_user_extras:
+
+  if (!a_extras_cnt) goto skip_extras;
+
+  stage_name  = "auto extras (over)";
+  stage_short = "ext_AO";
+  stage_cur   = 0;
+  stage_max   = MIN(a_extras_cnt, USE_AUTO_EXTRAS) * len;
+
+  stage_val_type = STAGE_VAL_NONE;
+
+  orig_hit_cnt = new_hit_cnt;
+
+  for (i = 0; i < len; i++) {
+
+    u32 last_len = 0;
+
+    stage_cur_byte = i;
+
+    for (j = 0; j < MIN(a_extras_cnt, USE_AUTO_EXTRAS); j++) {
+
+      /* See the comment in the earlier code; extras are sorted by size. */
+
+      if (a_extras[j].len > len - i ||
+          !memcmp(a_extras[j].data, out_buf + i, a_extras[j].len) ||
+          !memchr(eff_map + EFF_APOS(i), 1, EFF_SPAN_ALEN(i, a_extras[j].len))) {
+
+        stage_max--;
+        continue;
+
+      }
+
+      last_len = a_extras[j].len;
+      memcpy(out_buf + i, a_extras[j].data, last_len);
+
+      if (common_fuzz_stuff(argv, out_buf, len)) goto abandon_entry;
+
+      stage_cur++;
+
+    }
+
+    /* Restore all the clobbered memory. */
+    memcpy(out_buf + i, in_buf + i, last_len);
+
+  }
+
+  new_hit_cnt = queued_paths + unique_crashes;
+
+  stage_finds[STAGE_EXTRAS_AO]  += new_hit_cnt - orig_hit_cnt;
+  stage_cycles[STAGE_EXTRAS_AO] += stage_max;
+
+skip_extras:
+
+  /* If we made this to here without jumping to havoc_stage or abandon_entry,
+     we're properly done with deterministic steps and can mark it as such
+     in the .state/ directory. */
+
+  if (!queue_cur->passed_det) mark_as_det_done(queue_cur);
+
+  /****************
+   * RANDOM HAVOC *
+   ****************/
+
+havoc_stage:
+
+  stage_cur_byte = -1;
+
+  /* The havoc stage mutation code is also invoked when splicing files; if the
+     splice_cycle variable is set, generate different descriptions and such. */
+
+  if (!splice_cycle) {
+
+    stage_name  = "havoc";
+    stage_short = "havoc";
+    stage_max   = HAVOC_CYCLES * perf_score / havoc_div / 100;
+
+  } else {
+
+    static u8 tmp[32];
+
+    perf_score = orig_perf;
+
+    sprintf(tmp, "splice %u", splice_cycle);
+    stage_name  = tmp;
+    stage_short = "splice";
+    stage_max   = SPLICE_HAVOC * perf_score / havoc_div / 100;
+
+  }
+
+  if (stage_max < HAVOC_MIN) stage_max = HAVOC_MIN;
+
+  temp_len = len;
+
+  orig_hit_cnt = queued_paths + unique_crashes;
+
+  havoc_queued = queued_paths;
+
+  /* We essentially just do several thousand runs (depending on perf_score)
+     where we take the input file and make random stacked tweaks. */
+
+  for (stage_cur = 0; stage_cur < stage_max; stage_cur++) {
+
+    u32 use_stacking = 1 << (1 + UR(HAVOC_STACK_POW2));
+
+    stage_cur_val = use_stacking;
+ 
+    for (i = 0; i < use_stacking; i++) {
+
+      switch (UR(15 + ((extras_cnt + a_extras_cnt) ? 2 : 0))) {
+
+        case 0:
+
+          /* Flip a single bit somewhere. Spooky! */
+
+          FLIP_BIT(out_buf, UR(temp_len << 3));
+          break;
+
+        case 1: 
+
+          /* Set byte to interesting value. */
+
+          out_buf[UR(temp_len)] = interesting_8[UR(sizeof(interesting_8))];
+          break;
+
+        case 2:
+
+          /* Set word to interesting value, randomly choosing endian. */
+
+          if (temp_len < 2) break;
+
+          if (UR(2)) {
+
+            *(u16*)(out_buf + UR(temp_len - 1)) =
+              interesting_16[UR(sizeof(interesting_16) >> 1)];
+
+          } else {
+
+            *(u16*)(out_buf + UR(temp_len - 1)) = SWAP16(
+              interesting_16[UR(sizeof(interesting_16) >> 1)]);
+
+          }
+
+          break;
+
+        case 3:
+
+          /* Set dword to interesting value, randomly choosing endian. */
+
+          if (temp_len < 4) break;
+
+          if (UR(2)) {
+  
+            *(u32*)(out_buf + UR(temp_len - 3)) =
+              interesting_32[UR(sizeof(interesting_32) >> 2)];
+
+          } else {
+
+            *(u32*)(out_buf + UR(temp_len - 3)) = SWAP32(
+              interesting_32[UR(sizeof(interesting_32) >> 2)]);
+
+          }
+
+          break;
+
+        case 4:
+
+          /* Randomly subtract from byte. */
+
+          out_buf[UR(temp_len)] -= 1 + UR(ARITH_MAX);
+          break;
+
+        case 5:
+
+          /* Randomly add to byte. */
+
+          out_buf[UR(temp_len)] += 1 + UR(ARITH_MAX);
+          break;
+
+        case 6:
+
+          /* Randomly subtract from word, random endian. */
+
+          if (temp_len < 2) break;
+
+          if (UR(2)) {
+
+            u32 pos = UR(temp_len - 1);
+
+            *(u16*)(out_buf + pos) -= 1 + UR(ARITH_MAX);
+
+          } else {
+
+            u32 pos = UR(temp_len - 1);
+            u16 num = 1 + UR(ARITH_MAX);
+
+            *(u16*)(out_buf + pos) =
+              SWAP16(SWAP16(*(u16*)(out_buf + pos)) - num);
+
+          }
+
+          break;
+
+        case 7:
+
+          /* Randomly add to word, random endian. */
+
+          if (temp_len < 2) break;
+
+          if (UR(2)) {
+
+            u32 pos = UR(temp_len - 1);
+
+            *(u16*)(out_buf + pos) += 1 + UR(ARITH_MAX);
+
+          } else {
+
+            u32 pos = UR(temp_len - 1);
+            u16 num = 1 + UR(ARITH_MAX);
+
+            *(u16*)(out_buf + pos) =
+              SWAP16(SWAP16(*(u16*)(out_buf + pos)) + num);
+
+          }
+
+          break;
+
+        case 8:
+
+          /* Randomly subtract from dword, random endian. */
+
+          if (temp_len < 4) break;
+
+          if (UR(2)) {
+
+            u32 pos = UR(temp_len - 3);
+
+            *(u32*)(out_buf + pos) -= 1 + UR(ARITH_MAX);
+
+          } else {
+
+            u32 pos = UR(temp_len - 3);
+            u32 num = 1 + UR(ARITH_MAX);
+
+            *(u32*)(out_buf + pos) =
+              SWAP32(SWAP32(*(u32*)(out_buf + pos)) - num);
+
+          }
+
+          break;
+
+        case 9:
+
+          /* Randomly add to dword, random endian. */
+
+          if (temp_len < 4) break;
+
+          if (UR(2)) {
+
+            u32 pos = UR(temp_len - 3);
+
+            *(u32*)(out_buf + pos) += 1 + UR(ARITH_MAX);
+
+          } else {
+
+            u32 pos = UR(temp_len - 3);
+            u32 num = 1 + UR(ARITH_MAX);
+
+            *(u32*)(out_buf + pos) =
+              SWAP32(SWAP32(*(u32*)(out_buf + pos)) + num);
+
+          }
+
+          break;
+
+        case 10:
+
+          /* Just set a random byte to a random value. Because,
+             why not. We use XOR with 1-255 to eliminate the
+             possibility of a no-op. */
+
+          out_buf[UR(temp_len)] ^= 1 + UR(255);
+          break;
+
+        case 11 ... 12: {
+
+            /* Delete bytes. We're making this a bit more likely
+               than insertion (the next option) in hopes of keeping
+               files reasonably small. */
+
+            u32 del_from, del_len;
+
+            if (temp_len < 2) break;
+
+            /* Don't delete too much. */
+
+            del_len = choose_block_len(temp_len - 1);
+
+            del_from = UR(temp_len - del_len + 1);
+
+            memmove(out_buf + del_from, out_buf + del_from + del_len,
+                    temp_len - del_from - del_len);
+
+            temp_len -= del_len;
+
+            break;
+
+          }
+
+        case 13:
+
+          if (temp_len + HAVOC_BLK_LARGE < MAX_FILE) {
+
+            /* Clone bytes (75%) or insert a block of constant bytes (25%). */
+
+            u32 clone_from, clone_to, clone_len;
+            u8* new_buf;
+
+            clone_len  = choose_block_len(temp_len);
+
+            clone_from = UR(temp_len - clone_len + 1);
+            clone_to   = UR(temp_len);
+
+            new_buf = ck_alloc_nozero(temp_len + clone_len);
+
+            /* Head */
+
+            memcpy(new_buf, out_buf, clone_to);
+
+            /* Inserted part */
+
+            if (UR(4))
+              memcpy(new_buf + clone_to, out_buf + clone_from, clone_len);
+            else
+              memset(new_buf + clone_to, UR(256), clone_len);
+
+            /* Tail */
+            memcpy(new_buf + clone_to + clone_len, out_buf + clone_to,
+                   temp_len - clone_to);
+
+            ck_free(out_buf);
+            out_buf = new_buf;
+            temp_len += clone_len;
+
+          }
+
+          break;
+
+        case 14: {
+
+            /* Overwrite bytes with a randomly selected chunk (75%) or fixed
+               bytes (25%). */
+
+            u32 copy_from, copy_to, copy_len;
+
+            if (temp_len < 2) break;
+
+            copy_len  = choose_block_len(temp_len - 1);
+
+            copy_from = UR(temp_len - copy_len + 1);
+            copy_to   = UR(temp_len - copy_len + 1);
+
+            if (UR(4)) {
+
+              if (copy_from != copy_to)
+                memmove(out_buf + copy_to, out_buf + copy_from, copy_len);
+
+            } else memset(out_buf + copy_to, UR(256), copy_len);
+
+            break;
+
+          }
+
+        /* Values 15 and 16 can be selected only if there are any extras
+           present in the dictionaries. */
+
+        case 15: {
+
+            /* Overwrite bytes with an extra. */
+
+            if (!extras_cnt || (a_extras_cnt && UR(2))) {
+
+              /* No user-specified extras or odds in our favor. Let's use an
+                 auto-detected one. */
+
+              u32 use_extra = UR(a_extras_cnt);
+              u32 extra_len = a_extras[use_extra].len;
+              u32 insert_at;
+
+              if (extra_len > temp_len) break;
+
+              insert_at = UR(temp_len - extra_len + 1);
+              memcpy(out_buf + insert_at, a_extras[use_extra].data, extra_len);
+
+            } else {
+
+              /* No auto extras or odds in our favor. Use the dictionary. */
+
+              u32 use_extra = UR(extras_cnt);
+              u32 extra_len = extras[use_extra].len;
+              u32 insert_at;
+
+              if (extra_len > temp_len) break;
+
+              insert_at = UR(temp_len - extra_len + 1);
+              memcpy(out_buf + insert_at, extras[use_extra].data, extra_len);
+
+            }
+
+            break;
+
+          }
+
+        case 16: {
+
+            u32 use_extra, extra_len, insert_at = UR(temp_len);
+            u8* new_buf;
+
+            /* Insert an extra. Do the same dice-rolling stuff as for the
+               previous case. */
+
+            if (!extras_cnt || (a_extras_cnt && UR(2))) {
+
+              use_extra = UR(a_extras_cnt);
+              extra_len = a_extras[use_extra].len;
+
+              if (temp_len + extra_len >= MAX_FILE) break;
+
+              new_buf = ck_alloc_nozero(temp_len + extra_len);
+
+              /* Head */
+              memcpy(new_buf, out_buf, insert_at);
+
+              /* Inserted part */
+              memcpy(new_buf + insert_at, a_extras[use_extra].data, extra_len);
+
+            } else {
+
+              use_extra = UR(extras_cnt);
+              extra_len = extras[use_extra].len;
+
+              if (temp_len + extra_len >= MAX_FILE) break;
+
+              new_buf = ck_alloc_nozero(temp_len + extra_len);
+
+              /* Head */
+              memcpy(new_buf, out_buf, insert_at);
+
+              /* Inserted part */
+              memcpy(new_buf + insert_at, extras[use_extra].data, extra_len);
+
+            }
+
+            /* Tail */
+            memcpy(new_buf + insert_at + extra_len, out_buf + insert_at,
+                   temp_len - insert_at);
+
+            ck_free(out_buf);
+            out_buf   = new_buf;
+            temp_len += extra_len;
+
+            break;
+
+          }
+
+      }
+
+    }
+
+    if (common_fuzz_stuff(argv, out_buf, temp_len))
+      goto abandon_entry;
+
+    /* 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);
+    temp_len = len;
+    memcpy(out_buf, in_buf, len);
+
+    /* If we're finding new stuff, let's run for a bit longer, limits
+       permitting. */
+
+    if (queued_paths != havoc_queued) {
+
+      if (perf_score <= HAVOC_MAX_MULT * 100) {
+        stage_max  *= 2;
+        perf_score *= 2;
+      }
+
+      havoc_queued = queued_paths;
+
+    }
+
+  }
+
+  new_hit_cnt = queued_paths + unique_crashes;
+
+  if (!splice_cycle) {
+    stage_finds[STAGE_HAVOC]  += new_hit_cnt - orig_hit_cnt;
+    stage_cycles[STAGE_HAVOC] += stage_max;
+  } else {
+    stage_finds[STAGE_SPLICE]  += new_hit_cnt - orig_hit_cnt;
+    stage_cycles[STAGE_SPLICE] += stage_max;
+  }
+
+#ifndef IGNORE_FINDS
+
+  /************
+   * SPLICING *
+   ************/
+
+  /* This is a last-resort strategy triggered by a full round with no findings.
+     It takes the current input file, randomly selects another input, and
+     splices them together at some offset, then relies on the havoc
+     code to mutate that blob. */
+
+retry_splicing:
+
+  if (use_splicing && splice_cycle++ < SPLICE_CYCLES &&
+      queued_paths > 1 && queue_cur->len > 1) {
+
+    struct queue_entry* target;
+    u32 tid, split_at;
+    u8* new_buf;
+    s32 f_diff, l_diff;
+
+    /* First of all, if we've modified in_buf for havoc, let's clean that
+       up... */
+
+    if (in_buf != orig_in) {
+      ck_free(in_buf);
+      in_buf = orig_in;
+      len = queue_cur->len;
+    }
+
+    /* Pick a random queue entry and seek to it. Don't splice with yourself. */
+
+    do { tid = UR(queued_paths); } while (tid == current_entry);
+
+    splicing_with = tid;
+    target = queue;
+
+    while (tid >= 100) { target = target->next_100; tid -= 100; }
+    while (tid--) target = target->next;
+
+    /* Make sure that the target has a reasonable length. */
+
+    while (target && (target->len < 2 || target == queue_cur)) {
+      target = target->next;
+      splicing_with++;
+    }
+
+    if (!target) goto retry_splicing;
+
+    /* Read the 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);
+
+    ck_read(fd, new_buf, target->len, target->fname);
+
+    close(fd);
+
+    /* Find a suitable splicing location, somewhere between the first and
+       the last differing byte. Bail out if the difference is just a single
+       byte or so. */
+
+    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;
+    }
+
+    /* Split somewhere between the first and last differing byte. */
+
+    split_at = f_diff + UR(l_diff - f_diff);
+
+    /* Do the thing. */
+
+    len = target->len;
+    memcpy(new_buf, in_buf, split_at);
+    in_buf = new_buf;
+
+    ck_free(out_buf);
+    out_buf = ck_alloc_nozero(len);
+    memcpy(out_buf, in_buf, len);
+
+    goto havoc_stage;
+
+  }
+
+#endif /* !IGNORE_FINDS */
+
+  ret_val = 0;
+
+abandon_entry:
+
+  splicing_with = -1;
+
+  /* Update pending_not_fuzzed count if we made it through the calibration
+     cycle and have not seen this entry before. */
+
+  if (!stop_soon && !queue_cur->cal_failed && !queue_cur->was_fuzzed) {
+    queue_cur->was_fuzzed = 1;
+    pending_not_fuzzed--;
+    if (queue_cur->favored) pending_favored--;
+  }
+
+  munmap(orig_in, 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
+
+}
+
+
+/* Grab interesting test cases from other fuzzers. */
+
+static void sync_fuzzers(char** argv) {
+
+  DIR* sd;
+  struct dirent* sd_ent;
+  u32 sync_cnt = 0;
+
+  sd = opendir(sync_dir);
+  if (!sd) PFATAL("Unable to open '%s'", sync_dir);
+
+  stage_max = stage_cur = 0;
+  cur_depth = 0;
+
+  /* Look at the entries created for every other fuzzer in the sync directory. */
+
+  while ((sd_ent = readdir(sd))) {
+
+    static u8 stage_tmp[128];
+
+    DIR* qd;
+    struct dirent* qd_ent;
+    u8 *qd_path, *qd_synced_path;
+    u32 min_accept = 0, next_min_accept;
+
+    s32 id_fd;
+
+    /* Skip dot files and our own output directory. */
+
+    if (sd_ent->d_name[0] == '.' || !strcmp(sync_id, sd_ent->d_name)) continue;
+
+    /* Skip anything that doesn't have a queue/ subdirectory. */
+
+    qd_path = alloc_printf("%s/%s/queue", sync_dir, sd_ent->d_name);
+
+    if (!(qd = opendir(qd_path))) {
+      ck_free(qd_path);
+      continue;
+    }
+
+    /* Retrieve the ID of the last seen test case. */
+
+    qd_synced_path = alloc_printf("%s/.synced/%s", out_dir, sd_ent->d_name);
+
+    id_fd = open(qd_synced_path, O_RDWR | O_CREAT, 0600);
+
+    if (id_fd < 0) PFATAL("Unable to create '%s'", qd_synced_path);
+
+    if (read(id_fd, &min_accept, sizeof(u32)) > 0) 
+      lseek(id_fd, 0, SEEK_SET);
+
+    next_min_accept = min_accept;
+
+    /* Show stats */    
+
+    sprintf(stage_tmp, "sync %u", ++sync_cnt);
+    stage_name = stage_tmp;
+    stage_cur  = 0;
+    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. */
+
+    while ((qd_ent = readdir(qd))) {
+
+      u8* path;
+      s32 fd;
+      struct stat st;
+
+      if (qd_ent->d_name[0] == '.' ||
+          sscanf(qd_ent->d_name, CASE_PREFIX "%06u", &syncing_case) != 1 || 
+          syncing_case < min_accept) continue;
+
+      /* OK, sounds like a new one. Let's give it a try. */
+
+      if (syncing_case >= next_min_accept)
+        next_min_accept = syncing_case + 1;
+
+      path = alloc_printf("%s/%s", qd_path, qd_ent->d_name);
+
+      fd = open(path, O_RDONLY);
+      if (fd < 0) PFATAL("Unable to open '%s'", path);
+
+      if (fstat(fd, &st)) PFATAL("fstat() failed");
+
+      /* Ignore zero-sized or oversized files. */
+
+      if (st.st_size && st.st_size <= MAX_FILE) {
+
+        u8  fault;
+        u8* mem = mmap(0, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
+
+        if (mem == MAP_FAILED) PFATAL("Unable to mmap '%s'", path);
+
+        /* See what happens. We rely on save_if_interesting() to catch major
+           errors and save the test case. */
+
+        write_to_testcase(mem, st.st_size);
+
+        fault = run_target(argv);
+
+        if (stop_soon) return;
+
+        syncing_party = sd_ent->d_name;
+        queued_imported += save_if_interesting(argv, mem, st.st_size, fault);
+        syncing_party = 0;
+
+        munmap(mem, st.st_size);
+
+        if (!(stage_cur++ % stats_update_freq)) show_stats();
+
+      }
+
+      ck_free(path);
+      close(fd);
+
+    }
+
+    ck_write(id_fd, &next_min_accept, sizeof(u32), qd_synced_path);
+
+    close(id_fd);
+    closedir(qd);
+    ck_free(qd_path);
+    ck_free(qd_synced_path);
+    
+  }  
+
+  closedir(sd);
+
+}
+
+
+/* Handle stop signal (Ctrl-C, etc). */
+
+static void handle_stop_sig(int sig) {
+
+  stop_soon = 1; 
+
+  if (child_pid > 0) kill(child_pid, SIGKILL);
+  if (forksrv_pid > 0) kill(forksrv_pid, SIGKILL);
+
+}
+
+
+/* Handle skip request (SIGUSR1). */
+
+static void handle_skipreq(int sig) {
+
+  skip_requested = 1;
+
+}
+
+/* Handle timeout (SIGALRM). */
+
+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);
+
+  }
+
+}
+
+
+/* Do a PATH search and find target binary to see that it exists and
+   isn't a shell script - a common and painful mistake. We also check for
+   a valid ELF header and for evidence of AFL instrumentation. */
+
+EXP_ST void check_binary(u8* fname) {
+
+  u8* env_path = 0;
+  struct stat st;
+
+  s32 fd;
+  u8* f_data;
+  u32 f_len = 0;
+
+  ACTF("Validating target binary...");
+
+  if (strchr(fname, '/') || !(env_path = getenv("PATH"))) {
+
+    target_path = ck_strdup(fname);
+    if (stat(target_path, &st) || !S_ISREG(st.st_mode) ||
+        !(st.st_mode & 0111) || (f_len = st.st_size) < 4)
+      FATAL("Program '%s' not found or not executable", fname);
+
+  } else {
+
+    while (env_path) {
+
+      u8 *cur_elem, *delim = strchr(env_path, ':');
+
+      if (delim) {
+
+        cur_elem = ck_alloc(delim - env_path + 1);
+        memcpy(cur_elem, env_path, delim - env_path);
+        delim++;
+
+      } else cur_elem = ck_strdup(env_path);
+
+      env_path = delim;
+
+      if (cur_elem[0])
+        target_path = alloc_printf("%s/%s", cur_elem, fname);
+      else
+        target_path = ck_strdup(fname);
+
+      ck_free(cur_elem);
+
+      if (!stat(target_path, &st) && S_ISREG(st.st_mode) &&
+          (st.st_mode & 0111) && (f_len = st.st_size) >= 4) break;
+
+      ck_free(target_path);
+      target_path = 0;
+
+    }
+
+    if (!target_path) FATAL("Program '%s' not found or not executable", fname);
+
+  }
+
+  if (getenv("AFL_SKIP_BIN_CHECK")) return;
+
+  /* Check for blatant user errors. */
+
+  if ((!strncmp(target_path, "/tmp/", 5) && !strchr(target_path + 5, '/')) ||
+      (!strncmp(target_path, "/var/tmp/", 9) && !strchr(target_path + 9, '/')))
+     FATAL("Please don't keep binaries in /tmp or /var/tmp");
+
+  fd = open(target_path, O_RDONLY);
+
+  if (fd < 0) PFATAL("Unable to open '%s'", target_path);
+
+  f_data = mmap(0, f_len, PROT_READ, MAP_PRIVATE, fd, 0);
+
+  if (f_data == MAP_FAILED) PFATAL("Unable to mmap file '%s'", target_path);
+
+  close(fd);
+
+  if (f_data[0] == '#' && f_data[1] == '!') {
+
+    SAYF("\n" cLRD "[-] " cRST
+         "Oops, the target binary looks like a shell script. Some build systems will\n"
+         "    sometimes generate shell stubs for dynamically linked programs; try static\n"
+         "    library mode (./configure --disable-shared) if that's the case.\n\n"
+
+         "    Another possible cause is that you are actually trying to use a shell\n" 
+         "    wrapper around the fuzzed component. Invoking shell can slow down the\n" 
+         "    fuzzing process by a factor of 20x or more; it's best to write the wrapper\n"
+         "    in a compiled language instead.\n");
+
+    FATAL("Program '%s' is a shell script", target_path);
+
+  }
+
+#ifndef __APPLE__
+
+  if (f_data[0] != 0x7f || memcmp(f_data + 1, "ELF", 3))
+    FATAL("Program '%s' is not an ELF binary", target_path);
+
+#else
+
+  if (f_data[0] != 0xCF || f_data[1] != 0xFA || f_data[2] != 0xED)
+    FATAL("Program '%s' is not a 64-bit Mach-O binary", target_path);
+
+#endif /* ^!__APPLE__ */
+
+  if (!qemu_mode && !dumb_mode &&
+      !memmem(f_data, f_len, SHM_ENV_VAR, strlen(SHM_ENV_VAR) + 1)) {
+
+    SAYF("\n" cLRD "[-] " cRST
+         "Looks like the target binary is not instrumented! The fuzzer depends on\n"
+         "    compile-time instrumentation to isolate interesting test cases while\n"
+         "    mutating the input data. For more information, and for tips on how to\n"
+         "    instrument binaries, please see %s/README.\n\n"
+
+         "    When source code is not available, you may be able to leverage QEMU\n"
+         "    mode support. Consult the README for tips on how to enable this.\n"
+
+         "    (It is also possible to use afl-fuzz as a traditional, \"dumb\" fuzzer.\n"
+         "    For that, you can use the -n option - but expect much worse results.)\n",
+         doc_path);
+
+    FATAL("No instrumentation detected");
+
+  }
+
+  if (qemu_mode &&
+      memmem(f_data, f_len, SHM_ENV_VAR, strlen(SHM_ENV_VAR) + 1)) {
+
+    SAYF("\n" cLRD "[-] " cRST
+         "This program appears to be instrumented with afl-gcc, but is being run in\n"
+         "    QEMU mode (-Q). This is probably not what you want - this setup will be\n"
+         "    slow and offer no practical benefits.\n");
+
+    FATAL("Instrumentation found in -Q mode");
+
+  }
+
+  if (memmem(f_data, f_len, "libasan.so", 10) ||
+      memmem(f_data, f_len, "__msan_init", 11)) uses_asan = 1;
+
+  /* Detect persistent & deferred init signatures in the binary. */
+
+  if (memmem(f_data, f_len, PERSIST_SIG, strlen(PERSIST_SIG) + 1)) {
+
+    OKF(cPIN "Persistent mode binary detected.");
+    setenv(PERSIST_ENV_VAR, "1", 1);
+    no_var_check = 1;
+
+  } else if (getenv("AFL_PERSISTENT")) {
+
+    WARNF("AFL_PERSISTENT is no longer supported and may misbehave!");
+
+  }
+
+  if (memmem(f_data, f_len, DEFER_SIG, strlen(DEFER_SIG) + 1)) {
+
+    OKF(cPIN "Deferred forkserver binary detected.");
+    setenv(DEFER_ENV_VAR, "1", 1);
+
+  } else if (getenv("AFL_DEFER_FORKSRV")) {
+
+    WARNF("AFL_DEFER_FORKSRV is no longer supported and may misbehave!");
+
+  }
+
+  if (munmap(f_data, f_len)) PFATAL("unmap() failed");
+
+}
+
+
+/* Trim and possibly create a banner for the run. */
+
+static void fix_up_banner(u8* name) {
+
+  if (!use_banner) {
+
+    if (sync_id) {
+
+      use_banner = sync_id;
+
+    } else {
+
+      u8* trim = strrchr(name, '/');
+      if (!trim) use_banner = name; else use_banner = trim + 1;
+
+    }
+
+  }
+
+  if (strlen(use_banner) > 40) {
+
+    u8* tmp = ck_alloc(44);
+    sprintf(tmp, "%.40s...", use_banner);
+    use_banner = tmp;
+
+  }
+
+}
+
+
+/* Check if we're on TTY. */
+
+static void check_if_tty(void) {
+
+  struct winsize ws;
+
+  if (ioctl(1, TIOCGWINSZ, &ws)) {
+
+    if (errno == ENOTTY) {
+      OKF("Looks like we're not running on a tty, so I'll be a bit less verbose.");
+      not_on_tty = 1;
+    }
+
+    return;
+  }
+
+}
+
+
+/* Check terminal dimensions after resize. */
+
+static void check_term_size(void) {
+
+  struct winsize ws;
+
+  term_too_small = 0;
+
+  if (ioctl(1, TIOCGWINSZ, &ws)) return;
+
+  if (ws.ws_row < 25 || ws.ws_col < 80) term_too_small = 1;
+
+}
+
+
+
+/* Display usage hints. */
+
+static void usage(u8* argv0) {
+
+  SAYF("\n%s [ options ] -- /path/to/fuzzed_app [ ... ]\n\n"
+
+       "Required parameters:\n\n"
+
+       "  -i dir        - input directory with test cases\n"
+       "  -o dir        - output directory for fuzzer findings\n\n"
+
+       "Execution control settings:\n\n"
+
+       "  -f file       - location read by the fuzzed program (stdin)\n"
+       "  -t msec       - timeout for each run (auto-scaled, 50-%u ms)\n"
+       "  -m megs       - memory limit for child process (%u MB)\n"
+       "  -Q            - use binary-only instrumentation (QEMU mode)\n\n"     
+ 
+       "Fuzzing behavior settings:\n\n"
+
+       "  -d            - quick & dirty mode (skips deterministic steps)\n"
+       "  -n            - fuzz without instrumentation (dumb mode)\n"
+       "  -x dir        - optional fuzzer dictionary (see README)\n\n"
+
+       "Other stuff:\n\n"
+
+       "  -T text       - text banner to show on the screen\n"
+       "  -M / -S id    - distributed mode (see parallel_fuzzing.txt)\n"
+#ifdef HAVE_AFFINITY
+       "  -Z core_id    - set CPU affinity (see perf_tips.txt)\n"
+#endif /* HAVE_AFFINITY */
+       "  -C            - crash exploration mode (the peruvian rabbit thing)\n\n"
+
+       "For additional tips, please consult %s/README.\n\n",
+
+       argv0, EXEC_TIMEOUT, MEM_LIMIT, doc_path);
+
+  exit(1);
+
+}
+
+
+/* Prepare output directories and fds. */
+
+EXP_ST void setup_dirs_fds(void) {
+
+  u8* tmp;
+  s32 fd;
+
+  ACTF("Setting up output directories...");
+
+  if (sync_id && mkdir(sync_dir, 0700) && errno != EEXIST)
+      PFATAL("Unable to create '%s'", sync_dir);
+
+  if (mkdir(out_dir, 0700)) {
+
+    if (errno != EEXIST) PFATAL("Unable to create '%s'", out_dir);
+
+    maybe_delete_out_dir();
+
+  } else {
+
+    if (in_place_resume)
+      FATAL("Resume attempted but old output directory not found");
+
+    out_dir_fd = open(out_dir, O_RDONLY);
+
+#ifndef __sun
+
+    if (out_dir_fd < 0 || flock(out_dir_fd, LOCK_EX | LOCK_NB))
+      PFATAL("Unable to flock() output directory.");
+
+#endif /* !__sun */
+
+  }
+
+  /* Queue directory for any starting & discovered paths. */
+
+  tmp = alloc_printf("%s/queue", out_dir);
+  if (mkdir(tmp, 0700)) PFATAL("Unable to create '%s'", tmp);
+  ck_free(tmp);
+
+  /* Top-level directory for queue metadata used for session
+     resume and related tasks. */
+
+  tmp = alloc_printf("%s/queue/.state/", out_dir);
+  if (mkdir(tmp, 0700)) PFATAL("Unable to create '%s'", tmp);
+  ck_free(tmp);
+
+  /* Directory for flagging queue entries that went through
+     deterministic fuzzing in the past. */
+
+  tmp = alloc_printf("%s/queue/.state/deterministic_done/", out_dir);
+  if (mkdir(tmp, 0700)) PFATAL("Unable to create '%s'", tmp);
+  ck_free(tmp);
+
+  /* Directory with the auto-selected dictionary entries. */
+
+  tmp = alloc_printf("%s/queue/.state/auto_extras/", out_dir);
+  if (mkdir(tmp, 0700)) PFATAL("Unable to create '%s'", tmp);
+  ck_free(tmp);
+
+  /* The set of paths currently deemed redundant. */
+
+  tmp = alloc_printf("%s/queue/.state/redundant_edges/", out_dir);
+  if (mkdir(tmp, 0700)) PFATAL("Unable to create '%s'", tmp);
+  ck_free(tmp);
+
+  /* The set of paths showing variable behavior. */
+
+  tmp = alloc_printf("%s/queue/.state/variable_behavior/", out_dir);
+  if (mkdir(tmp, 0700)) PFATAL("Unable to create '%s'", tmp);
+  ck_free(tmp);
+
+  /* Sync directory for keeping track of cooperating fuzzers. */
+
+  if (sync_id) {
+
+    tmp = alloc_printf("%s/.synced/", out_dir);
+    if (mkdir(tmp, 0700)) PFATAL("Unable to create '%s'", tmp);
+    ck_free(tmp);
+
+  }
+
+  /* All recorded crashes. */
+
+  tmp = alloc_printf("%s/crashes", out_dir);
+  if (mkdir(tmp, 0700)) PFATAL("Unable to create '%s'", tmp);
+  ck_free(tmp);
+
+  /* All recorded hangs. */
+
+  tmp = alloc_printf("%s/hangs", out_dir);
+  if (mkdir(tmp, 0700)) PFATAL("Unable to create '%s'", tmp);
+  ck_free(tmp);
+
+  /* Generally useful file descriptors. */
+
+  dev_null_fd = open("/dev/null", O_RDWR);
+  if (dev_null_fd < 0) PFATAL("Unable to open /dev/null");
+
+  dev_urandom_fd = open("/dev/urandom", O_RDONLY);
+  if (dev_urandom_fd < 0) PFATAL("Unable to open /dev/urandom");
+
+  /* Gnuplot output file. */
+
+  tmp = alloc_printf("%s/plot_data", out_dir);
+  fd = open(tmp, O_WRONLY | O_CREAT | O_EXCL, 0600);
+  if (fd < 0) PFATAL("Unable to create '%s'", tmp);
+  ck_free(tmp);
+
+  plot_file = fdopen(fd, "w");
+  if (!plot_file) PFATAL("fdopen() failed");
+
+  fprintf(plot_file, "# unix_time, cycles_done, cur_path, paths_total, "
+                     "pending_total, pending_favs, map_size, unique_crashes, "
+                     "unique_hangs, max_depth, execs_per_sec\n");
+                     /* ignore errors */
+
+}
+
+
+/* Setup the output file for fuzzed data, if not using -f. */
+
+EXP_ST void setup_stdio_file(void) {
+
+  u8* fn = alloc_printf("%s/.cur_input", out_dir);
+
+  unlink(fn); /* Ignore errors */
+
+  out_fd = open(fn, O_RDWR | O_CREAT | O_EXCL, 0600);
+
+  if (out_fd < 0) PFATAL("Unable to create '%s'", fn);
+
+  ck_free(fn);
+
+}
+
+
+/* Make sure that core dumps don't go to a program. */
+
+static void check_crash_handling(void) {
+
+#ifdef __APPLE__
+
+  /* Yuck! There appears to be no simple C API to query for the state of 
+     loaded daemons on MacOS X, and I'm a bit hesitant to do something
+     more sophisticated, such as disabling crash reporting via Mach ports,
+     until I get a box to test the code. So, for now, we check for crash
+     reporting the awful way. */
+  
+  if (system("launchctl list 2>/dev/null | grep -q '\\.ReportCrash$'")) return;
+
+  SAYF("\n" cLRD "[-] " cRST
+       "Whoops, your system is configured to forward crash notifications to an\n"
+       "    external crash reporting utility. This will cause issues due to the\n"
+       "    extended delay between the fuzzed binary malfunctioning and this fact\n"
+       "    being relayed to the fuzzer via the standard waitpid() API.\n\n"
+       "    To avoid having crashes misinterpreted as hangs, please run the\n" 
+       "    following commands:\n\n"
+
+       "    SL=/System/Library; PL=com.apple.ReportCrash\n"
+       "    launchctl unload -w ${SL}/LaunchAgents/${PL}.plist\n"
+       "    sudo launchctl unload -w ${SL}/LaunchDaemons/${PL}.Root.plist\n");
+
+  if (!getenv("AFL_I_DONT_CARE_ABOUT_MISSING_CRASHES"))
+    FATAL("Crash reporter detected");
+
+#else
+
+  /* This is Linux specific, but I don't think there's anything equivalent on
+     *BSD, so we can just let it slide for now. */
+
+  s32 fd = open("/proc/sys/kernel/core_pattern", O_RDONLY);
+  u8  fchar;
+
+  if (fd < 0) return;
+
+  ACTF("Checking core_pattern...");
+
+  if (read(fd, &fchar, 1) == 1 && fchar == '|') {
+
+    SAYF("\n" cLRD "[-] " cRST
+         "Hmm, your system is configured to send core dump notifications to an\n"
+         "    external utility. This will cause issues: there will be an extended delay\n"
+         "    between stumbling upon a crash and having this information relayed to the\n"
+         "    fuzzer via the standard waitpid() API.\n\n"
+
+         "    To avoid having crashes misinterpreted as hangs, please log in as root\n" 
+         "    and temporarily modify /proc/sys/kernel/core_pattern, like so:\n\n"
+
+         "    echo core >/proc/sys/kernel/core_pattern\n");
+
+    if (!getenv("AFL_I_DONT_CARE_ABOUT_MISSING_CRASHES"))
+      FATAL("Pipe at the beginning of 'core_pattern'");
+
+  }
+ 
+  close(fd);
+
+#endif /* ^__APPLE__ */
+
+}
+
+
+/* Check CPU governor. */
+
+static void check_cpu_governor(void) {
+
+  FILE* f;
+  u8 tmp[128];
+  u64 min = 0, max = 0;
+
+  if (getenv("AFL_SKIP_CPUFREQ")) return;
+
+  f = fopen("/sys/devices/system/cpu/cpu0/cpufreq/scaling_governor", "r");
+  if (!f) return;
+
+  ACTF("Checking CPU scaling governor...");
+
+  if (!fgets(tmp, 128, f)) PFATAL("fgets() failed");
+
+  fclose(f);
+
+  if (!strncmp(tmp, "perf", 4)) return;
+
+  f = fopen("/sys/devices/system/cpu/cpu0/cpufreq/scaling_min_freq", "r");
+
+  if (f) {
+    if (fscanf(f, "%llu", &min) != 1) min = 0;
+    fclose(f);
+  }
+
+  f = fopen("/sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq", "r");
+
+  if (f) {
+    if (fscanf(f, "%llu", &max) != 1) max = 0;
+    fclose(f);
+  }
+
+  if (min == max) return;
+
+  SAYF("\n" cLRD "[-] " cRST
+       "Whoops, your system uses on-demand CPU frequency scaling, adjusted\n"
+       "    between %llu and %llu MHz. Unfortunately, the scaling algorithm in the\n"
+       "    kernel is imperfect and can miss the short-lived processes spawned by\n"
+       "    afl-fuzz. To keep things moving, run these commands as root:\n\n"
+
+       "    cd /sys/devices/system/cpu\n"
+       "    echo performance | tee cpu*/cpufreq/scaling_governor\n\n"
+
+       "    You can later go back to the original state by replacing 'performance' with\n"
+       "    'ondemand'. If you don't want to change the settings, set AFL_SKIP_CPUFREQ\n"
+       "    to make afl-fuzz skip this check - but expect some performance drop.\n",
+       min / 1024, max / 1024);
+
+  FATAL("Suboptimal CPU scaling governor");
+
+}
+
+
+/* Count the number of logical CPU cores. */
+
+static void get_core_count(void) {
+
+  u32 cur_runnable = 0;
+
+#if defined(__APPLE__) || defined(__FreeBSD__) || defined (__OpenBSD__)
+
+  size_t s = sizeof(cpu_core_count);
+
+  /* On *BSD systems, we can just use a sysctl to get the number of CPUs. */
+
+#ifdef __APPLE__
+
+  if (sysctlbyname("hw.logicalcpu", &cpu_core_count, &s, NULL, 0) < 0)
+    return;
+
+#else
+
+  int s_name[2] = { CTL_HW, HW_NCPU };
+
+  if (sysctl(s_name, 2, &cpu_core_count, &s, NULL, 0) < 0) return;
+
+#endif /* ^__APPLE__ */
+
+#else
+
+  if (!cpu_core_count) {
+
+    /* On Linux, a simple way is to look at /proc/stat, especially since we'd
+       be parsing it anyway for other reasons later on. But do this only if
+       cpu_core_count hasn't been obtained before as a result of specifying
+       -Z. */
+
+    FILE* f = fopen("/proc/stat", "r");
+    u8 tmp[1024];
+
+    if (!f) return;
+
+    while (fgets(tmp, sizeof(tmp), f))
+      if (!strncmp(tmp, "cpu", 3) && isdigit(tmp[3])) cpu_core_count++;
+
+    fclose(f);
+  }
+
+#endif /* ^(__APPLE__ || __FreeBSD__ || __OpenBSD__) */
+
+  if (cpu_core_count) {
+
+    cur_runnable = (u32)get_runnable_processes();
+
+#if defined(__APPLE__) || defined(__FreeBSD__) || defined (__OpenBSD__)
+
+    /* Add ourselves, since the 1-minute average doesn't include that yet. */
+
+    cur_runnable++;
+
+#endif /* __APPLE__ || __FreeBSD__ || __OpenBSD__ */
+
+    OKF("You have %u CPU cores and %u runnable tasks (utilization: %0.0f%%).",
+        cpu_core_count, cur_runnable, cur_runnable * 100.0 / cpu_core_count);
+
+    if (cpu_core_count > 1) {
+
+      if (cur_runnable > cpu_core_count * 1.5) {
+
+        WARNF("System under apparent load, performance may be spotty.");
+
+      } else if (cur_runnable + 1 <= cpu_core_count) {
+
+        OKF("Try parallel jobs - see %s/parallel_fuzzing.txt.", doc_path);
+  
+      }
+
+    }
+
+  } else WARNF("Unable to figure out the number of CPU cores.");
+
+#ifdef HAVE_AFFINITY
+
+  if (use_affinity)
+    OKF("Using specified CPU affinity: main = %u, child = %u",
+        cpu_aff_main, cpu_aff_child);
+  else if (cpu_core_count > 1)
+    OKF(cBRI "Try setting CPU affinity (-Z) for a performance boost!" cRST);
+
+#endif /* HAVE_AFFINITY */
+
+}
+
+
+/* Validate and fix up out_dir and sync_dir when using -S. */
+
+static void fix_up_sync(void) {
+
+  u8* x = sync_id;
+
+  if (dumb_mode)
+    FATAL("-S / -M and -n are mutually exclusive");
+
+  if (skip_deterministic) {
+
+    if (force_deterministic)
+      FATAL("use -S instead of -M -d");
+    else
+      FATAL("-S already implies -d");
+
+  }
+
+  while (*x) {
+
+    if (!isalnum(*x) && *x != '_' && *x != '-')
+      FATAL("Non-alphanumeric fuzzer ID specified via -S or -M");
+
+    x++;
+
+  }
+
+  if (strlen(sync_id) > 32) FATAL("Fuzzer ID too long");
+
+  x = alloc_printf("%s/%s", out_dir, sync_id);
+
+  sync_dir = out_dir;
+  out_dir  = x;
+
+  if (!force_deterministic) {
+    skip_deterministic = 1;
+    use_splicing = 1;
+  }
+
+}
+
+
+/* Handle screen resize (SIGWINCH). */
+
+static void handle_resize(int sig) {
+  clear_screen = 1;
+}
+
+
+/* Check ASAN options. */
+
+static void check_asan_opts(void) {
+  u8* x = getenv("ASAN_OPTIONS");
+
+  if (x) {
+
+    if (!strstr(x, "abort_on_error=1"))
+      FATAL("Custom ASAN_OPTIONS set without abort_on_error=1 - please fix!");
+
+    if (!strstr(x, "symbolize=0"))
+      FATAL("Custom ASAN_OPTIONS set without symbolize=0 - please fix!");
+
+  }
+
+  x = getenv("MSAN_OPTIONS");
+
+  if (x) {
+
+    if (!strstr(x, "exit_code=" STRINGIFY(MSAN_ERROR)))
+      FATAL("Custom MSAN_OPTIONS set without exit_code="
+            STRINGIFY(MSAN_ERROR) " - please fix!");
+
+    if (!strstr(x, "symbolize=0"))
+      FATAL("Custom MSAN_OPTIONS set without symbolize=0 - please fix!");
+
+  }
+
+} 
+
+
+/* Detect @@ in args. */
+
+EXP_ST void detect_file_args(char** argv) {
+
+  u32 i = 0;
+  u8* cwd = getcwd(NULL, 0);
+
+  if (!cwd) PFATAL("getcwd() failed");
+
+  while (argv[i]) {
+
+    u8* aa_loc = strstr(argv[i], "@@");
+
+    if (aa_loc) {
+
+      u8 *aa_subst, *n_arg;
+
+      /* If we don't have a file name chosen yet, use a safe default. */
+
+      if (!out_file)
+        out_file = alloc_printf("%s/.cur_input", out_dir);
+
+      /* Be sure that we're always using fully-qualified paths. */
+
+      if (out_file[0] == '/') aa_subst = out_file;
+      else aa_subst = alloc_printf("%s/%s", cwd, out_file);
+
+      /* Construct a replacement argv value. */
+
+      *aa_loc = 0;
+      n_arg = alloc_printf("%s%s%s", argv[i], aa_subst, aa_loc + 2);
+      argv[i] = n_arg;
+      *aa_loc = '@';
+
+      if (out_file[0] != '/') ck_free(aa_subst);
+
+    }
+
+    i++;
+
+  }
+
+  free(cwd); /* not tracked */
+
+}
+
+
+/* Set up signal handlers. More complicated that needs to be, because libc on
+   Solaris doesn't resume interrupted reads(), sets SA_RESETHAND when you call
+   siginterrupt(), and does other stupid things. */
+
+EXP_ST void setup_signal_handlers(void) {
+
+  struct sigaction sa;
+
+  sa.sa_handler   = NULL;
+  sa.sa_flags     = SA_RESTART;
+  sa.sa_sigaction = NULL;
+
+  sigemptyset(&sa.sa_mask);
+
+  /* Various ways of saying "stop". */
+
+  sa.sa_handler = handle_stop_sig;
+  sigaction(SIGHUP, &sa, NULL);
+  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;
+  sigaction(SIGWINCH, &sa, NULL);
+
+  /* SIGUSR1: skip entry */
+
+  sa.sa_handler = handle_skipreq;
+  sigaction(SIGUSR1, &sa, NULL);
+
+  /* Things we don't care about. */
+
+  sa.sa_handler = SIG_IGN;
+  sigaction(SIGTSTP, &sa, NULL);
+  sigaction(SIGPIPE, &sa, NULL);
+
+}
+
+
+/* Rewrite argv for QEMU. */
+
+static char** get_qemu_argv(u8* own_loc, char** argv, int argc) {
+
+  char** new_argv = ck_alloc(sizeof(char*) * (argc + 4));
+  u8 *tmp, *cp, *rsl, *own_copy;
+
+  memcpy(new_argv + 3, argv + 1, sizeof(char*) * argc);
+
+  new_argv[2] = target_path;
+  new_argv[1] = "--";
+
+  /* Now we need to actually find the QEMU binary to put in argv[0]. */
+
+  tmp = getenv("AFL_PATH");
+
+  if (tmp) {
+
+    cp = alloc_printf("%s/afl-qemu-trace", tmp);
+
+    if (access(cp, X_OK))
+      FATAL("Unable to find '%s'", tmp);
+
+    target_path = new_argv[0] = cp;
+    return new_argv;
+
+  }
+
+  own_copy = ck_strdup(own_loc);
+  rsl = strrchr(own_copy, '/');
+
+  if (rsl) {
+
+    *rsl = 0;
+
+    cp = alloc_printf("%s/afl-qemu-trace", own_copy);
+    ck_free(own_copy);
+
+    if (!access(cp, X_OK)) {
+
+      target_path = new_argv[0] = cp;
+      return new_argv;
+
+    }
+
+  } else ck_free(own_copy);
+
+  if (!access(BIN_PATH "/afl-qemu-trace", X_OK)) {
+
+    target_path = new_argv[0] = ck_strdup(BIN_PATH "/afl-qemu-trace");
+    return new_argv;
+
+  }
+
+  SAYF("\n" cLRD "[-] " cRST
+       "Oops, unable to find the 'afl-qemu-trace' binary. The binary must be built\n"
+       "    separately by following the instructions in qemu_mode/README.qemu. If you\n"
+       "    already have the binary installed, you may need to specify AFL_PATH in the\n"
+       "    environment.\n\n"
+
+       "    Of course, even without QEMU, afl-fuzz can still work with binaries that are\n"
+       "    instrumented at compile time with afl-gcc. It is also possible to use it as a\n"
+       "    traditional \"dumb\" fuzzer by specifying '-n' in the command line.\n");
+
+  FATAL("Failed to locate 'afl-qemu-trace'.");
+
+}
+
+
+/* Make a copy of the current command line. */
+
+static void save_cmdline(u32 argc, char** argv) {
+
+  u32 len = 1, i;
+  u8* buf;
+
+  for (i = 0; i < argc; i++)
+    len += strlen(argv[i]) + 1;
+  
+  buf = orig_cmdline = ck_alloc(len);
+
+  for (i = 0; i < argc; i++) {
+
+    u32 l = strlen(argv[i]);
+
+    memcpy(buf, argv[i], l);
+    buf += l;
+
+    if (i != argc - 1) *(buf++) = ' ';
+
+  }
+
+  *buf = 0;
+
+}
+
+
+#ifndef AFL_LIB
+
+/* Main entry point */
+
+int main(int argc, char** argv) {
+
+  s32 opt;
+  u64 prev_queued = 0;
+  u32 sync_interval_cnt = 0, seek_to;
+  u8  *extras_dir = 0;
+  u8  mem_limit_given = 0;
+  u8  exit_1 = !!getenv("AFL_BENCH_JUST_ONE");
+
+  char** use_argv;
+
+  SAYF(cCYA "afl-fuzz " cBRI VERSION cRST " by <lcamtuf@google.com>\n");
+
+  doc_path = access(DOC_PATH, F_OK) ? "docs" : DOC_PATH;
+
+  while ((opt = getopt(argc, argv, "+i:o:f:m:t:T:dnCB:S:M:x:QZ:")) > 0)
+
+    switch (opt) {
+
+      case 'i':
+
+        if (in_dir) FATAL("Multiple -i options not supported");
+        in_dir = optarg;
+
+        if (!strcmp(in_dir, "-")) in_place_resume = 1;
+
+        break;
+
+      case 'o': /* output dir */
+
+        if (out_dir) FATAL("Multiple -o options not supported");
+        out_dir = optarg;
+        break;
+
+      case 'M':
+
+        force_deterministic = 1;
+        /* Fall through */
+
+      case 'S': /* sync ID */
+
+        if (sync_id) FATAL("Multiple -S or -M options not supported");
+        sync_id = optarg;
+        break;
+
+      case 'f': /* target file */
+
+        if (out_file) FATAL("Multiple -f options not supported");
+        out_file = optarg;
+        break;
+
+      case 'x':
+
+        if (extras_dir) FATAL("Multiple -x options not supported");
+        extras_dir = optarg;
+        break;
+
+      case 't': {
+
+          u8 suffix = 0;
+
+          if (timeout_given) FATAL("Multiple -t options not supported");
+
+          if (sscanf(optarg, "%u%c", &exec_tmout, &suffix) < 1 ||
+              optarg[0] == '-') FATAL("Bad syntax used for -t");
+
+          if (exec_tmout < 5) FATAL("Dangerously low value of -t");
+
+          if (suffix == '+') timeout_given = 2; else timeout_given = 1;
+
+          break;
+
+      }
+
+      case 'm': {
+
+          u8 suffix = 'M';
+
+          if (mem_limit_given) FATAL("Multiple -m options not supported");
+          mem_limit_given = 1;
+
+          if (!strcmp(optarg, "none")) {
+
+            mem_limit = 0;
+            break;
+
+          }
+
+          if (sscanf(optarg, "%llu%c", &mem_limit, &suffix) < 1 ||
+              optarg[0] == '-') FATAL("Bad syntax used for -m");
+
+          switch (suffix) {
+
+            case 'T': mem_limit *= 1024 * 1024; break;
+            case 'G': mem_limit *= 1024; break;
+            case 'k': mem_limit /= 1024; break;
+            case 'M': break;
+
+            default:  FATAL("Unsupported suffix or bad syntax for -m");
+
+          }
+
+          if (mem_limit < 5) FATAL("Dangerously low value of -m");
+
+          if (sizeof(rlim_t) == 4 && mem_limit > 2000)
+            FATAL("Value of -m out of range on 32-bit systems");
+
+        }
+
+        break;
+
+#ifdef HAVE_AFFINITY
+
+      case 'Z': {
+
+          s32 i;
+
+          if (use_affinity) FATAL("Multiple -Z options not supported");
+          use_affinity = 1;
+
+          cpu_core_count = sysconf(_SC_NPROCESSORS_ONLN);
+
+          i = sscanf(optarg, "%u,%u", &cpu_aff_main, &cpu_aff_child);
+
+          if (i < 1 || cpu_aff_main >= cpu_core_count) 
+            FATAL("Bogus primary core ID passed to -Z (expected 0-%u)",
+                  cpu_core_count - 1);
+
+          if (i == 1) cpu_aff_child = cpu_aff_main;
+
+          if (cpu_aff_child >= cpu_core_count)
+            FATAL("Bogus secondary core ID passed to -Z (expected 0-%u)",
+                  cpu_core_count - 1);
+
+          break;
+
+        }
+
+#endif /* HAVE_AFFINITY */
+
+      case 'd':
+
+        if (skip_deterministic) FATAL("Multiple -d options not supported");
+        skip_deterministic = 1;
+        use_splicing = 1;
+        break;
+
+      case 'B':
+
+        /* This is a secret undocumented option! It is useful if you find
+           an interesting test case during a normal fuzzing process, and want
+           to mutate it without rediscovering any of the test cases already
+           found during an earlier run.
+
+           To use this mode, you need to point -B to the fuzz_bitmap produced
+           by an earlier run for the exact same binary... and that's it.
+
+           I only used this once or twice to get variants of a particular
+           file, so I'm not making this an official setting. */
+
+        if (in_bitmap) FATAL("Multiple -B options not supported");
+
+        in_bitmap = optarg;
+        read_bitmap(in_bitmap);
+        break;
+
+      case 'C':
+
+        if (crash_mode) FATAL("Multiple -C options not supported");
+        crash_mode = FAULT_CRASH;
+        break;
+
+      case 'n':
+
+        if (dumb_mode) FATAL("Multiple -n options not supported");
+        if (getenv("AFL_DUMB_FORKSRV")) dumb_mode = 2; else dumb_mode = 1;
+
+        break;
+
+      case 'T':
+
+        if (use_banner) FATAL("Multiple -T options not supported");
+        use_banner = optarg;
+        break;
+
+      case 'Q':
+
+        if (qemu_mode) FATAL("Multiple -Q options not supported");
+        qemu_mode = 1;
+
+        if (!mem_limit_given) mem_limit = MEM_LIMIT_QEMU;
+
+        break;
+
+      default:
+
+        usage(argv[0]);
+
+    }
+
+  if (optind == argc || !in_dir || !out_dir) usage(argv[0]);
+
+  setup_signal_handlers();
+  check_asan_opts();
+
+#ifdef HAVE_AFFINITY
+  if (use_affinity) set_cpu_affinity(cpu_aff_main);
+#endif /* HAVE_AFFINITY */
+
+  if (sync_id) fix_up_sync();
+
+  if (!strcmp(in_dir, out_dir))
+    FATAL("Input and output directories can't be the same");
+
+  if (dumb_mode) {
+
+    if (crash_mode) FATAL("-C and -n are mutually exclusive");
+    if (qemu_mode)  FATAL("-Q and -n are mutually exclusive");
+
+  }
+
+  if (getenv("AFL_NO_FORKSRV"))    no_forkserver    = 1;
+  if (getenv("AFL_NO_CPU_RED"))    no_cpu_meter_red = 1;
+  if (getenv("AFL_NO_VAR_CHECK"))  no_var_check     = 1;
+  if (getenv("AFL_SHUFFLE_QUEUE")) shuffle_queue    = 1;
+
+  if (dumb_mode == 2 && no_forkserver)
+    FATAL("AFL_DUMB_FORKSRV and AFL_NO_FORKSRV are mutually exclusive");
+
+  if (getenv("AFL_LD_PRELOAD"))
+    setenv("LD_PRELOAD", getenv("AFL_LD_PRELOAD"), 1);
+
+  save_cmdline(argc, argv);
+
+  fix_up_banner(argv[optind]);
+
+  check_if_tty();
+
+  get_core_count();
+  check_crash_handling();
+  check_cpu_governor();
+
+  setup_post();
+  setup_shm();
+
+  setup_dirs_fds();
+  read_testcases();
+  load_auto();
+
+  pivot_inputs();
+
+  if (extras_dir) load_extras(extras_dir);
+
+  if (!timeout_given) find_timeout();
+
+  detect_file_args(argv + optind + 1);
+
+  if (!out_file) setup_stdio_file();
+
+  check_binary(argv[optind]);
+
+  start_time = get_cur_time();
+
+  if (qemu_mode)
+    use_argv = get_qemu_argv(argv[0], argv + optind, argc - optind);
+  else
+    use_argv = argv + optind;
+
+  perform_dry_run(use_argv);
+
+  cull_queue();
+
+  show_init_stats();
+
+  seek_to = find_start_position();
+
+  write_stats_file(0, 0);
+  save_auto();
+
+  if (stop_soon) goto stop_fuzzing;
+
+  /* Woop woop woop */
+
+  if (!not_on_tty) {
+    sleep(4);
+    start_time += 4000;
+    if (stop_soon) goto stop_fuzzing;
+  }
+
+  while (1) {
+
+    u8 skipped_fuzz;
+
+    cull_queue();
+
+    if (!queue_cur) {
+
+      queue_cycle++;
+      current_entry     = 0;
+      cur_skipped_paths = 0;
+      queue_cur         = queue;
+
+      while (seek_to) {
+        current_entry++;
+        seek_to--;
+        queue_cur = queue_cur->next;
+      }
+
+      show_stats();
+
+      if (not_on_tty) {
+        ACTF("Entering queue cycle %llu.", queue_cycle);
+        fflush(stdout);
+      }
+
+      /* If we had a full queue cycle with no new finds, try
+         recombination strategies next. */
+
+      if (queued_paths == prev_queued) {
+
+        if (use_splicing) cycles_wo_finds++; else use_splicing = 1;
+
+      } else cycles_wo_finds = 0;
+
+      prev_queued = queued_paths;
+
+      if (sync_id && queue_cycle == 1 && getenv("AFL_IMPORT_FIRST"))
+        sync_fuzzers(use_argv);
+
+    }
+
+    skipped_fuzz = fuzz_one(use_argv);
+
+    if (!stop_soon && sync_id && !skipped_fuzz) {
+      
+      if (!(sync_interval_cnt++ % SYNC_INTERVAL))
+        sync_fuzzers(use_argv);
+
+    }
+
+    if (!stop_soon && exit_1) stop_soon = 2;
+
+    if (stop_soon) break;
+
+    queue_cur = queue_cur->next;
+    current_entry++;
+
+  }
+
+  if (queue_cur) show_stats();
+
+  write_bitmap();
+  write_stats_file(0, 0);
+  save_auto();
+
+stop_fuzzing:
+
+  SAYF(CURSOR_SHOW cLRD "\n\n+++ Testing aborted %s +++\n" cRST,
+       stop_soon == 2 ? "programatically" : "by user");
+
+  /* Running for more than 30 minutes but still doing first cycle? */
+
+  if (queue_cycle == 1 && get_cur_time() - start_time > 30 * 60 * 1000) {
+
+    SAYF("\n" cYEL "[!] " cRST
+           "Stopped during the first cycle, results may be incomplete.\n"
+           "    (For info on resuming, see %s/README.)\n", doc_path);
+
+  }
+
+  fclose(plot_file);
+  destroy_queue();
+  destroy_extras();
+  ck_free(target_path);
+
+  alloc_report();
+
+  OKF("We're done here. Have a nice day!\n");
+
+  exit(0);
+
+}
+
+#endif /* !AFL_LIB */