Revert "Merge branch 'memcache_marc' into dev"

This reverts commit c03fbcedaa68db5324423975a34331287426f7c2, reversing
changes made to dab017dddaaab6d836a590f7bba3eea3549758d2.

5 files changed, 97 insertions, 177 deletions

diff --git a/include/afl-fuzz.h b/include/afl-fuzz.h
index a3e87129..45de197d 100644
--- a/include/afl-fuzz.h
+++ b/include/afl-fuzz.h
@@ -168,9 +168,6 @@ struct queue_entry {
 
   double perf_score;                    /* performance score                */
 
-  u8 *testcase_buf;                     /* The testcase buffer, if loaded.  */
-  u32 testcase_refs;                    /* count of users of testcase buf   */
-
   struct queue_entry *next;             /* Next element, if any             */
 
 };
@@ -689,12 +686,6 @@ typedef struct afl_state {
   /* queue entries ready for splicing count (len > 4) */
   u32 ready_for_splicing_count;
 
-  /* How many queue entries currently have cached testcases */
-  u32 q_testcase_cache_count;
-  /* Refs to each queue entry with cached testcase (for eviction, if cache_count
-   * is too large) */
-  struct queue_entry *q_testcase_cache[TESTCASE_CACHE_SIZE];
-
 } afl_state_t;
 
 struct custom_mutator {
@@ -1141,12 +1132,5 @@ static inline u64 next_p2(u64 val) {
 
 }
 
-/* Returns the testcase buf from the file behind this queue entry.
-  Increases the refcount. */
-u8 *queue_testcase_take(afl_state_t *afl, struct queue_entry *q);
-
-/* Tell afl that this testcase may be evicted from the cache */
-void queue_testcase_release(afl_state_t *afl, struct queue_entry *q);
-
 #endif
 
diff --git a/include/config.h b/include/config.h
index 3f498275..7dd045e3 100644
--- a/include/config.h
+++ b/include/config.h
@@ -295,15 +295,6 @@
 
 #define RESEED_RNG 100000
 
-/* The amount of entries in the testcase cache, held in memory.
-Decrease if RAM usage is high. */
-#define TESTCASE_CACHE_SIZE 3072
-
-#if TESTCASE_CACHE_SIZE < 4
-  #error \
-      "Dangerously low cache size: Set TESTCASE_CACHE_SIZE to 4 or more in config.h!"
-#endif
-
 /* Maximum line length passed from GCC to 'as' and used for parsing
    configuration files: */
 
diff --git a/src/afl-fuzz-one.c b/src/afl-fuzz-one.c
index ebe541a2..6ef728e0 100644
--- a/src/afl-fuzz-one.c
+++ b/src/afl-fuzz-one.c
@@ -370,7 +370,7 @@ static void locate_diffs(u8 *ptr1, u8 *ptr2, u32 len, s32 *first, s32 *last) {
 
 u8 fuzz_one_original(afl_state_t *afl) {
 
-  s32 len, temp_len;
+  s32 len, fd, temp_len;
   u32 j;
   u32 i;
   u8 *in_buf, *out_buf, *orig_in, *ex_tmp, *eff_map = 0;
@@ -453,9 +453,28 @@ u8 fuzz_one_original(afl_state_t *afl) {
 
   }
 
-  orig_in = in_buf = queue_testcase_take(afl, afl->queue_cur);
+  /* Map the test case into memory. */
+
+  fd = open(afl->queue_cur->fname, O_RDONLY);
+
+  if (unlikely(fd < 0)) {
+
+    PFATAL("Unable to open '%s'", afl->queue_cur->fname);
+
+  }
+
   len = afl->queue_cur->len;
 
+  orig_in = in_buf = mmap(0, len, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
+
+  if (unlikely(orig_in == MAP_FAILED)) {
+
+    PFATAL("Unable to mmap '%s' with len %d", afl->queue_cur->fname, len);
+
+  }
+
+  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. */
@@ -1678,7 +1697,7 @@ custom_mutator_stage:
         for (afl->stage_cur = 0; afl->stage_cur < afl->stage_max;
              ++afl->stage_cur) {
 
-          struct queue_entry *target = NULL;
+          struct queue_entry *target;
           u32                 tid;
           u8 *                new_buf = NULL;
           u32                 target_len = 0;
@@ -1701,7 +1720,17 @@ custom_mutator_stage:
             afl->splicing_with = tid;
 
             /* Read the additional testcase into a new buffer. */
-            new_buf = queue_testcase_take(afl, target);
+            fd = open(target->fname, O_RDONLY);
+            if (unlikely(fd < 0)) {
+
+              PFATAL("Unable to open '%s'", target->fname);
+
+            }
+
+            new_buf = afl_realloc(AFL_BUF_PARAM(out_scratch), target->len);
+            if (unlikely(!new_buf)) { PFATAL("alloc"); }
+            ck_read(fd, new_buf, target->len, target->fname);
+            close(fd);
             target_len = target->len;
 
           }
@@ -1712,13 +1741,6 @@ custom_mutator_stage:
               el->afl_custom_fuzz(el->data, out_buf, len, &mutated_buf, new_buf,
                                   target_len, max_seed_size);
 
-          if (new_buf) {
-
-            queue_testcase_release(afl, target);
-            new_buf = NULL;
-
-          }
-
           if (unlikely(!mutated_buf)) {
 
             FATAL("Error in custom_fuzz. Size returned: %zd", mutated_size);
@@ -2301,53 +2323,52 @@ havoc_stage:
             /* Overwrite bytes with a randomly selected chunk from another
                testcase or insert that chunk. */
 
-            if (afl->queued_paths < 4) { break; }
+            if (afl->queued_paths < 4) break;
 
             /* Pick a random queue entry and seek to it. */
 
             u32 tid;
-            do {
-
+            do
               tid = rand_below(afl, afl->queued_paths);
-
-            } while (tid == afl->current_entry);
+            while (tid == afl->current_entry);
 
             struct queue_entry *target = afl->queue_buf[tid];
 
             /* Make sure that the target has a reasonable length. */
 
-            while (target && (target->len < 2 || target == afl->queue_cur)) {
-
+            while (target && (target->len < 2 || target == afl->queue_cur))
               target = target->next;
 
-            }
+            if (!target) break;
 
-            if (!target) { break; }
+            /* Read the testcase into a new buffer. */
 
-            u32 new_len = target->len;
+            fd = open(target->fname, O_RDONLY);
 
-            /* Get the testcase contents for splicing. */
-            u8 *new_buf = queue_testcase_take(afl, target);
+            if (unlikely(fd < 0)) {
 
-            u8 overwrite = 0;
-            if (temp_len >= 2 && rand_below(afl, 2)) {
+              PFATAL("Unable to open '%s'", target->fname);
 
-              overwrite = 1;
+            }
 
-            } else if (temp_len + HAVOC_BLK_XL >= MAX_FILE) {
+            u32 new_len = target->len;
+            u8 *new_buf = afl_realloc(AFL_BUF_PARAM(in_scratch), new_len);
+            if (unlikely(!new_buf)) { PFATAL("alloc"); }
 
-              if (temp_len >= 2) {
+            ck_read(fd, new_buf, new_len, target->fname);
 
-                overwrite = 1;
+            close(fd);
 
-              } else {
+            u8 overwrite = 0;
+            if (temp_len >= 2 && rand_below(afl, 2))
+              overwrite = 1;
+            else if (temp_len + HAVOC_BLK_XL >= MAX_FILE) {
 
-                queue_testcase_release(afl, target);
-                new_buf = NULL;
+              if (temp_len >= 2)
+                overwrite = 1;
+              else
                 break;
 
-              }
-
             }
 
             if (overwrite) {
@@ -2393,9 +2414,6 @@ havoc_stage:
 
             }
 
-            /* We don't need this splice testcase anymore */
-            queue_testcase_release(afl, target);
-            new_buf = NULL;
             break;
 
           }
@@ -2501,17 +2519,24 @@ retry_splicing:
 
     if (!target) { goto retry_splicing; }
 
-    /* Get the testcase buffer */
-    u8 *splice_buf = queue_testcase_take(afl, target);
+    /* Read the testcase into a new buffer. */
+
+    fd = open(target->fname, O_RDONLY);
+
+    if (unlikely(fd < 0)) { PFATAL("Unable to open '%s'", target->fname); }
+
     new_buf = afl_realloc(AFL_BUF_PARAM(in_scratch), target->len);
     if (unlikely(!new_buf)) { PFATAL("alloc"); }
 
+    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, splice_buf, MIN(len, (s64)target->len), &f_diff,
-                 &l_diff);
+    locate_diffs(in_buf, new_buf, MIN(len, (s64)target->len), &f_diff, &l_diff);
 
     if (f_diff < 0 || l_diff < 2 || f_diff == l_diff) { goto retry_splicing; }
 
@@ -2523,7 +2548,6 @@ retry_splicing:
 
     len = target->len;
     memcpy(new_buf, in_buf, split_at);
-    memcpy(new_buf + split_at, splice_buf + split_at, target->len - split_at);
     afl_swap_bufs(AFL_BUF_PARAM(in), AFL_BUF_PARAM(in_scratch));
     in_buf = new_buf;
 
@@ -2531,9 +2555,6 @@ retry_splicing:
     if (unlikely(!out_buf)) { PFATAL("alloc"); }
     memcpy(out_buf, in_buf, len);
 
-    queue_testcase_release(afl, target);
-    splice_buf = NULL;
-
     goto custom_mutator_stage;
     /* ???: While integrating Python module, the author decided to jump to
        python stage, but the reason behind this is not clear.*/
@@ -2564,8 +2585,7 @@ abandon_entry:
 
   ++afl->queue_cur->fuzz_level;
 
-  queue_testcase_release(afl, afl->queue_cur);
-  orig_in = NULL;
+  munmap(orig_in, afl->queue_cur->len);
 
   return ret_val;
 
@@ -2587,7 +2607,7 @@ static u8 mopt_common_fuzzing(afl_state_t *afl, MOpt_globals_t MOpt_globals) {
 
   }
 
-  s32 len, temp_len;
+  s32 len, fd, temp_len;
   u32 i;
   u32 j;
   u8 *in_buf, *out_buf, *orig_in, *ex_tmp, *eff_map = 0;
@@ -2652,9 +2672,23 @@ static u8 mopt_common_fuzzing(afl_state_t *afl, MOpt_globals_t MOpt_globals) {
   }
 
   /* Map the test case into memory. */
-  orig_in = in_buf = queue_testcase_take(afl, afl->queue_cur);
+
+  fd = open(afl->queue_cur->fname, O_RDONLY);
+
+  if (fd < 0) { PFATAL("Unable to open '%s'", afl->queue_cur->fname); }
+
   len = afl->queue_cur->len;
 
+  orig_in = in_buf = mmap(0, len, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
+
+  if (orig_in == MAP_FAILED) {
+
+    PFATAL("Unable to mmap '%s'", afl->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. */
@@ -4494,24 +4528,31 @@ pacemaker_fuzzing:
         if (!target) { goto retry_splicing_puppet; }
 
         /* Read the testcase into a new buffer. */
-        u8 *splicing_buf = queue_testcase_take(afl, target);
+
+        fd = open(target->fname, O_RDONLY);
+
+        if (fd < 0) { PFATAL("Unable to open '%s'", target->fname); }
+
+        new_buf = afl_realloc(AFL_BUF_PARAM(in_scratch), target->len);
+        if (unlikely(!new_buf)) { PFATAL("alloc"); }
+
+        ck_read(fd, new_buf, target->len, target->fname);
+
+        close(fd);
 
         /* Find a suitable splicin g 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, splicing_buf, MIN(len, (s32)target->len), &f_diff,
+        locate_diffs(in_buf, new_buf, MIN(len, (s32)target->len), &f_diff,
                      &l_diff);
 
         if (f_diff < 0 || l_diff < 2 || f_diff == l_diff) {
 
-          queue_testcase_release(afl, target);
           goto retry_splicing_puppet;
 
         }
 
-        new_buf = afl_realloc(AFL_BUF_PARAM(in_scratch), target->len);
-
         /* Split somewhere between the first and last differing byte. */
 
         split_at = f_diff + rand_below(afl, l_diff - f_diff);
@@ -4520,17 +4561,12 @@ pacemaker_fuzzing:
 
         len = target->len;
         memcpy(new_buf, in_buf, split_at);
-        memcpy(new_buf + split_at, splicing_buf + split_at,
-               target->len - split_at);
         afl_swap_bufs(AFL_BUF_PARAM(in), AFL_BUF_PARAM(in_scratch));
         in_buf = new_buf;
         out_buf = afl_realloc(AFL_BUF_PARAM(out), len);
         if (unlikely(!out_buf)) { PFATAL("alloc"); }
         memcpy(out_buf, in_buf, len);
 
-        queue_testcase_release(afl, target);
-        splicing_buf = NULL;
-
         goto havoc_stage_puppet;
 
       }                                                  /* if splice_cycle */
@@ -4564,8 +4600,7 @@ pacemaker_fuzzing:
       //   if (afl->queue_cur->favored) --afl->pending_favored;
       // }
 
-      queue_testcase_release(afl, afl->queue_cur);
-      orig_in = NULL;
+      munmap(orig_in, afl->queue_cur->len);
 
       if (afl->key_puppet == 1) {
 
diff --git a/src/afl-fuzz-queue.c b/src/afl-fuzz-queue.c
index a034b168..d608e890 100644
--- a/src/afl-fuzz-queue.c
+++ b/src/afl-fuzz-queue.c
@@ -343,7 +343,6 @@ void add_to_queue(afl_state_t *afl, u8 *fname, u32 len, u8 passed_det) {
   q->depth = afl->cur_depth + 1;
   q->passed_det = passed_det;
   q->trace_mini = NULL;
-  q->testcase_buf = NULL;
 
   if (q->depth > afl->max_depth) { afl->max_depth = q->depth; }
 
@@ -892,89 +891,3 @@ u32 calculate_score(afl_state_t *afl, struct queue_entry *q) {
 
 }
 
-/* Tell afl that this testcase may be evicted from the cache */
-inline void queue_testcase_release(afl_state_t *afl, struct queue_entry *q) {
-
-  (void)afl;
-  if (unlikely(q->testcase_refs == 0)) {
-
-    FATAL("Testcase refcount reduced past 0");
-
-  }
-
-  q->testcase_refs--;
-
-}
-
-/* Returns the testcase buf from the file behind this queue entry.
-  Increases the refcount. */
-u8 *queue_testcase_take(afl_state_t *afl, struct queue_entry *q) {
-
-  if (!q->testcase_buf) {
-
-    u32 tid = 0;
-    /* Buf not cached, let's do that now */
-
-    if (likely(afl->q_testcase_cache_count == TESTCASE_CACHE_SIZE)) {
-
-      /* Cache full. We neet to evict one to map one.
-      Get a random one which is not in use */
-      do {
-
-        tid = rand_below(afl, afl->q_testcase_cache_count);
-
-      } while (afl->q_testcase_cache[tid]->testcase_refs > 0);
-
-      struct queue_entry *old_cached = afl->q_testcase_cache[tid];
-      /* free the current buf from cache */
-      munmap(old_cached->testcase_buf, old_cached->len);
-      old_cached->testcase_buf = NULL;
-
-    } else {
-
-      tid = afl->q_testcase_cache_count;
-      afl->q_testcase_cache_count++;
-
-    }
-
-    /* Map the test case into memory. */
-
-    int fd = open(q->fname, O_RDONLY);
-
-    if (unlikely(fd < 0)) { PFATAL("Unable to open '%s'", q->fname); }
-
-    u32 len = q->len;
-
-    q->testcase_buf = mmap(0, len, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
-
-    if (unlikely(q->testcase_buf == MAP_FAILED)) {
-
-      PFATAL("Unable to mmap '%s' with len %d", q->fname, len);
-
-    }
-
-    close(fd);
-
-    /* Register us as cached */
-    afl->q_testcase_cache[tid] = q;
-
-  }
-
-  q->testcase_refs++;
-  if (unlikely(!q->testcase_buf || !q->testcase_refs)) {
-    if (!q->testcase_buf) {
-
-      FATAL("Testcase buf is NULL, this should never happen");
-
-    }
-    if (!q->testcase_refs) {
-
-      FATAL("Testcase ref overflow. Missing a testcase release somwhere?");
-
-    }
-  }
-
-  return q->testcase_buf;
-
-}
-
diff --git a/src/afl-fuzz.c b/src/afl-fuzz.c
index cb5eb37a..d42a0d36 100644
--- a/src/afl-fuzz.c
+++ b/src/afl-fuzz.c
@@ -1174,12 +1174,9 @@ int main(int argc, char **argv_orig, char **envp) {
 
   if (extras_dir_cnt) {
 
-    for (i = 0; i < extras_dir_cnt; i++) {
-
+    for (i = 0; i < extras_dir_cnt; i++)
       load_extras(afl, extras_dir[i]);
 
-    }
-
     dedup_extras(afl);
     OKF("Loaded a total of %u extras.", afl->extras_cnt);