diff options
Diffstat (limited to 'src/afl-fuzz-src/afl-fuzz.c')
| -rw-r--r-- | src/afl-fuzz-src/afl-fuzz.c | 691 |
1 files changed, 0 insertions, 691 deletions
diff --git a/src/afl-fuzz-src/afl-fuzz.c b/src/afl-fuzz-src/afl-fuzz.c index b93c17c8..dcb97387 100644 --- a/src/afl-fuzz-src/afl-fuzz.c +++ b/src/afl-fuzz-src/afl-fuzz.c @@ -45,34 +45,6 @@ int select_algorithm(void) { } -/* 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; - -} - - /* Shuffle an array of pointers. Might be slightly biased. */ static void shuffle_ptrs(void** ptrs, u32 cnt) { @@ -393,669 +365,6 @@ static u8* DTD(u64 cur_ms, u64 event_ms) { } -/* 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; - - 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) { - - s32 fd; - - 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; - q->n_fuzz = 1; - - 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. */ - -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. */ - -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. */ - -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. */ - -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--) { - - /* Optimize for (*current & *virgin) == 0 - i.e., no bits in current bitmap - that have not been already cleared from the virgin map - since this will - almost always be the case. */ - - if (unlikely(*current) && unlikely(*current & *virgin)) { - - if (likely(ret < 2)) { - - u8* cur = (u8*)current; - u8* vir = (u8*)virgin; - - /* Looks like we have not found any new bytes yet; see if any non-zero - bytes in current[] are pristine in virgin[]. */ - -#ifdef __x86_64__ - - if ((cur[0] && vir[0] == 0xff) || (cur[1] && vir[1] == 0xff) || - (cur[2] && vir[2] == 0xff) || (cur[3] && vir[3] == 0xff) || - (cur[4] && vir[4] == 0xff) || (cur[5] && vir[5] == 0xff) || - (cur[6] && vir[6] == 0xff) || (cur[7] && vir[7] == 0xff)) ret = 2; - else ret = 1; - -#else - - if ((cur[0] && vir[0] == 0xff) || (cur[1] && vir[1] == 0xff) || - (cur[2] && vir[2] == 0xff) || (cur[3] && vir[3] == 0xff)) ret = 2; - else ret = 1; - -#endif /* ^__x86_64__ */ - - } - - *virgin &= ~*current; - - } - - ++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; - -} - - -#define FF(_b) (0xff << ((_b) << 3)) - -/* Count the number of bytes set in the bitmap. Called fairly sporadically, - mostly to update the status screen or calibrate and examine confirmed - new paths. */ - -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 timeout, should be - reasonably fast. */ - -static const u8 simplify_lookup[256] = { - - [0] = 1, - [1 ... 255] = 128 - -}; - -#ifdef __x86_64__ - -static void simplify_trace(u64* mem) { - - u32 i = MAP_SIZE >> 3; - - while (i--) { - - /* Optimize for sparse bitmaps. */ - - if (unlikely(*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 (unlikely(*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 const u8 count_class_lookup8[256] = { - - [0] = 0, - [1] = 1, - [2] = 2, - [3] = 4, - [4 ... 7] = 8, - [8 ... 15] = 16, - [16 ... 31] = 32, - [32 ... 127] = 64, - [128 ... 255] = 128 - -}; - -static u16 count_class_lookup16[65536]; - - -void init_count_class16(void) { - - u32 b1, b2; - - for (b1 = 0; b1 < 256; b1++) - for (b2 = 0; b2 < 256; b2++) - count_class_lookup16[(b1 << 8) + b2] = - (count_class_lookup8[b1] << 8) | - count_class_lookup8[b2]; - -} - - -#ifdef __x86_64__ - -static inline void classify_counts(u64* mem) { - - u32 i = MAP_SIZE >> 3; - - while (i--) { - - /* Optimize for sparse bitmaps. */ - - if (unlikely(*mem)) { - - u16* mem16 = (u16*)mem; - - mem16[0] = count_class_lookup16[mem16[0]]; - mem16[1] = count_class_lookup16[mem16[1]]; - mem16[2] = count_class_lookup16[mem16[2]]; - mem16[3] = count_class_lookup16[mem16[3]]; - - } - - ++mem; - - } - -} - -#else - -static inline void classify_counts(u32* mem) { - - u32 i = MAP_SIZE >> 2; - - while (i--) { - - /* Optimize for sparse bitmaps. */ - - if (unlikely(*mem)) { - - u16* mem16 = (u16*)mem; - - mem16[0] = count_class_lookup16[mem16[0]]; - mem16[1] = count_class_lookup16[mem16[1]]; - - } - - ++mem; - - } - -} - -#endif /* ^__x86_64__ */ - - -/* 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; - - } - -} - - - -/* Find first power of two greater or equal to val (assuming val under - 2^63). */ - -static u64 next_p2(u64 val) { - - u64 ret = 1; - while (val > ret) ret <<= 1; - return ret; - -} - - -/* 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; - u64 fuzz_p2 = next_p2 (q->n_fuzz); - - /* 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. */ - u64 top_rated_fuzz_p2 = next_p2 (top_rated[i]->n_fuzz); - u64 top_rated_fav_factor = top_rated[i]->exec_us * top_rated[i]->len; - - if (fuzz_p2 > top_rated_fuzz_p2) { - continue; - } else if (fuzz_p2 == top_rated_fuzz_p2) { - if (fav_factor > top_rated_fav_factor) - continue; - } - - 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]->fuzz_level == 0 || !top_rated[i]->was_fuzzed) ++pending_favored; - - } - - q = queue; - - while (q) { - mark_as_redundant(q, !q->favored); - q = q->next; - } - -} - - /* Load postprocessor, if available. */ static void setup_post(void) { |