testcase cache added
MODIFY
include/afl-fuzz.h
include/afl-fuzz.h
@@ -162,6 +162,9 @@ struct queue_entry {
u8 *trace_mini; /* Trace bytes, if kept */
u32 tc_ref; /* Trace bytes ref count */
+ 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 */
};
@@ -664,6 +667,11 @@ 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 {
@@ -1101,5 +1109,12 @@ 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

MODIFY
include/config.h
include/config.h
#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 2048
+
+#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: */

MODIFY
src/afl-fuzz-one.c
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, fd, temp_len;
+ s32 len, temp_len;
u32 j;
u32 i;
u8 *in_buf, *out_buf, *orig_in, *ex_tmp, *eff_map = 0;
@@ -453,28 +453,9 @@ u8 fuzz_one_original(afl_state_t *afl) {
}
- /* 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);
-
- }
-
+ orig_in = in_buf = queue_testcase_take(afl, afl->queue_cur);
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. */
@@ -1694,7 +1675,7 @@ custom_mutator_stage:
for (afl->stage_cur = 0; afl->stage_cur < afl->stage_max;
++afl->stage_cur) {
- struct queue_entry *target;
+ struct queue_entry *target = NULL;
u32 tid;
u8 * new_buf = NULL;
u32 target_len = 0;
@@ -1717,17 +1698,7 @@ custom_mutator_stage:
afl->splicing_with = tid;
/* Read the additional 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(out_scratch), target->len);
- if (unlikely(!new_buf)) { PFATAL("alloc"); }
- ck_read(fd, new_buf, target->len, target->fname);
- close(fd);
+ new_buf = queue_testcase_take(afl, target);
target_len = target->len;
}
@@ -1738,6 +1709,11 @@ 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);
@@ -2320,51 +2296,44 @@ 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;
-
- /* Read the testcase into a new buffer. */
-
- fd = open(target->fname, O_RDONLY);
-
- if (unlikely(fd < 0)) {
-
- PFATAL("Unable to open '%s'", target->fname);
+ if (!target) { break; }
- }
u32 new_len = target->len;
- u8 *new_buf = afl_realloc(AFL_BUF_PARAM(in_scratch), new_len);
- if (unlikely(!new_buf)) { PFATAL("alloc"); }
-
- ck_read(fd, new_buf, new_len, target->fname);
- close(fd);
+ /* Get the testcase contents for splicing. */
+ u8 *new_buf = queue_testcase_take(afl, target);
u8 overwrite = 0;
- if (temp_len >= 2 && rand_below(afl, 2))
+ if (temp_len >= 2 && rand_below(afl, 2)) {
overwrite = 1;
+ }
else if (temp_len + HAVOC_BLK_XL >= MAX_FILE) {
- if (temp_len >= 2)
+ if (temp_len >= 2) {
overwrite = 1;
- else
+ } else {
+ queue_testcase_release(afl, target);
+ new_buf = NULL;
break;
+ }
}
@@ -2411,6 +2380,9 @@ havoc_stage:
}
+ /* We don't need this splice testcase anymore */
+ queue_testcase_release(afl, target);
+ new_buf = NULL;
break;
}
@@ -2516,24 +2488,16 @@ retry_splicing:
if (!target) { goto retry_splicing; }
- /* Read the testcase into a new buffer. */
-
- fd = open(target->fname, O_RDONLY);
-
- if (unlikely(fd < 0)) { PFATAL("Unable to open '%s'", target->fname); }
-
+ /* Get the testcase buffer */
+ u8 *splice_buf = queue_testcase_take(afl, target);
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, new_buf, MIN(len, (s64)target->len), &f_diff, &l_diff);
+ locate_diffs(in_buf, splice_buf, MIN(len, (s64)target->len), &f_diff, &l_diff);
if (f_diff < 0 || l_diff < 2 || f_diff == l_diff) { goto retry_splicing; }
@@ -2545,6 +2509,7 @@ 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;
@@ -2552,6 +2517,9 @@ 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.*/
@@ -2582,7 +2550,8 @@ abandon_entry:
++afl->queue_cur->fuzz_level;
- munmap(orig_in, afl->queue_cur->len);
+ queue_testcase_release(afl, afl->queue_cur);
+ orig_in = NULL;
return ret_val;
@@ -2604,7 +2573,7 @@ static u8 mopt_common_fuzzing(afl_state_t *afl, MOpt_globals_t MOpt_globals) {
}
- s32 len, fd, temp_len;
+ s32 len, temp_len;
u32 i;
u32 j;
u8 *in_buf, *out_buf, *orig_in, *ex_tmp, *eff_map = 0;
@@ -2669,23 +2638,9 @@ static u8 mopt_common_fuzzing(afl_state_t *afl, MOpt_globals_t MOpt_globals) {
}
/* Map the test case into memory. */
-
- fd = open(afl->queue_cur->fname, O_RDONLY);
-
- if (fd < 0) { PFATAL("Unable to open '%s'", afl->queue_cur->fname); }
-
+ orig_in = in_buf = queue_testcase_take(afl, afl->queue_cur);
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. */
@@ -4522,31 +4477,24 @@ pacemaker_fuzzing:
if (!target) { goto retry_splicing_puppet; }
/* 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 = 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);
+ u8 *splicing_buf = queue_testcase_take(afl, target);
/* 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, new_buf, MIN(len, (s32)target->len), &f_diff,
+ locate_diffs(in_buf, splicing_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);
@@ -4555,12 +4503,16 @@ 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 */
@@ -4594,7 +4546,8 @@ pacemaker_fuzzing:
// if (afl->queue_cur->favored) --afl->pending_favored;
// }
- munmap(orig_in, afl->queue_cur->len);
+ queue_testcase_release(afl, afl->queue_cur);
+ orig_in = NULL;
if (afl->key_puppet == 1) {
@@ -4730,6 +4683,9 @@ pacemaker_fuzzing:
} /* block */
+ queue_testcase_release(afl, afl->queue_cur);
+ orig_in = NULL;
+
return ret_val;
}

MODIFY
src/afl-fuzz-queue.c
src/afl-fuzz-queue.c
@@ -220,6 +220,7 @@ void add_to_queue(afl_state_t *afl, u8 *fname, u32 len, u8 passed_det) {
q->depth = afl->cur_depth + 1;
q->passed_det = passed_det;
q->trace_mini = NULL;
+ q->testcase_buf = NULL;
if (q->depth > afl->max_depth) { afl->max_depth = q->depth; }
@@ -767,3 +768,67 @@ 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;
+ q->testcase_refs--;
+ if (unlikely(q->testcase_refs < 0)) { FATAL("Testcase refcount smaller than 0"); }
+}
+
+/* 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 (!q->testcase_buf) { FATAL("Testcase buf is NULL, this should never happen"); }
+ return q->testcase_buf;
+
+}

MODIFY
src/afl-fuzz.c
src/afl-fuzz.c
@@ -1152,8 +1152,9 @@ 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);

testcase cache added