| // Copyright 2023 The Centipede Authors. |
| // |
| // 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 |
| // |
| // https://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| // |
| // Definitions of the Centipede flags to be expanded in different contexts. |
| // Each flag is defined as: |
| // |
| // CENTIPEDE_FLAG(type, name, default_value, description) |
| // |
| // default_value must be a compile-time constant. |
| // description must be a string literal. |
| |
| #ifndef CENTIPEDE_FLAG |
| #error This file must be used only in Centipede with CENTIPEDE_FLAG defined. |
| #endif |
| |
| // TODO(kcc): document usage of standalone binaries and how to use @@ wildcard. |
| // If the "binary" contains @@, it means the binary can only accept inputs |
| // from the command line, and only one input per process. |
| // @@ will be replaced with a path to file with the input. |
| // @@ is chosen to follow the AFL command line syntax. |
| // TODO(kcc): rename --binary to --command (same for --extra_binaries), |
| // while remaining backward compatible. |
| CENTIPEDE_FLAG(std::string, binary, "", "The target binary.") |
| CENTIPEDE_FLAG( |
| std::string, coverage_binary, "", |
| "The actual binary from which coverage is collected - if different " |
| "from --binary.") |
| CENTIPEDE_FLAG( |
| std::string, binary_hash, "", |
| "If not-empty, this hash string is used instead of the hash of the " |
| "contents of coverage_binary. Use this flag when the coverage_binary " |
| "is not available nor needed, e.g. when using --distill.") |
| CENTIPEDE_FLAG( |
| std::string, clang_coverage_binary, "", |
| "A clang source-based code coverage binary used to produce " |
| "human-readable reports. Do not add this binary to extra_binaries. " |
| "You must have llvm-cov and llvm-profdata in your path to generate " |
| "the reports. --workdir in turn must be local in order for this " |
| "functionality to work. See " |
| "https://clang.llvm.org/docs/SourceBasedCodeCoverage.html") |
| CENTIPEDE_FLAG(std::string, test_name, "", |
| "The name of test to pass to the binary to operate on.") |
| CENTIPEDE_FLAG( |
| std::vector<std::string>, extra_binaries, {}, |
| "A comma-separated list of extra target binaries. These binaries are " |
| "fed the same inputs as the main binary, but the coverage feedback " |
| "from them is not collected. Use this e.g. to run the target under " |
| "sanitizers.") |
| CENTIPEDE_FLAG(std::string, workdir, "", "The working directory.") |
| CENTIPEDE_FLAG( |
| std::string, merge_from, "", |
| "Another working directory to merge the corpus from. Inputs from " |
| "--merge_from will be added to --workdir if the add new features.") |
| CENTIPEDE_FLAG(size_t, num_runs, std::numeric_limits<size_t>::max(), |
| "Number of inputs to run per shard (see --total_shards).") |
| CENTIPEDE_FLAG(size_t, total_shards, 1, "Number of shards.") |
| CENTIPEDE_FLAG(size_t, my_shard_index, 0, |
| "Index of the first shard, [0, --total_shards - --num_threads].") |
| CENTIPEDE_FLAG( |
| size_t, num_threads, 1, |
| "Number of threads to execute in one process. i-th thread, where i " |
| "is in [0, --num_threads), will work on shard " |
| "(--first_shard_index + i).") |
| CENTIPEDE_FLAG(size_t, j, 0, |
| "If not 0, --j=N is a shorthand for " |
| "--num_threads=N --total_shards=N --first_shard_index=0. " |
| "Overrides values of these flags if they are also used.") |
| CENTIPEDE_FLAG(size_t, max_len, 4000, |
| "Max length of mutants. Passed to mutator as a hint.") |
| CENTIPEDE_FLAG( |
| size_t, batch_size, 1000, |
| "The number of inputs given to the target at one time. Batches of " |
| "more than 1 input are used to amortize the process start-up cost.") |
| CENTIPEDE_FLAG(size_t, mutate_batch_size, 2, |
| "Mutate this many inputs to produce batch_size mutants") |
| CENTIPEDE_FLAG( |
| bool, use_legacy_default_mutator, false, |
| "When set, use the legacy ByteArrayMutator as the default mutator. " |
| "Otherwise, the FuzzTest domain based mutator will be used.") |
| CENTIPEDE_FLAG( |
| size_t, load_other_shard_frequency, 10, |
| "Load a random other shard after processing this many batches. Use 0 " |
| "to disable loading other shards. For now, choose the value of this " |
| "flag so that shard loads happen at most once in a few minutes. In " |
| "future we may be able to find the suitable value automatically.") |
| // TODO(b/262798184): Remove once the bug is fixed. |
| CENTIPEDE_FLAG( |
| bool, serialize_shard_loads, false, |
| "When this flag is on, shard loading is serialized. " |
| " Useful to avoid excessive RAM consumption when loading more" |
| " that one shard at a time. Currently, loading a single large shard" |
| " may create too many temporary heap allocations. " |
| " This means, if we load many large shards concurrently," |
| " we may run out or RAM.") |
| CENTIPEDE_FLAG( |
| size_t, seed, 0, |
| "A seed for the random number generator. If 0, some other random " |
| "number is used as seed.") |
| CENTIPEDE_FLAG( |
| size_t, prune_frequency, 100, |
| "Prune the corpus every time after this many inputs were added. If " |
| "zero, pruning is disabled. Pruning removes redundant inputs from " |
| "the corpus, e.g. inputs that have only \"frequent\", i.e. " |
| "uninteresting features. When the corpus gets larger than " |
| "--max_corpus_size, some random elements may also be removed.") |
| CENTIPEDE_FLAG( |
| size_t, address_space_limit_mb, |
| #ifdef __APPLE__ |
| // Address space limit is ignored on MacOS. |
| // Reference: |
| // https://bugs.chromium.org/p/chromium/issues/detail?id=853873#c2 |
| 0 |
| #else |
| 8192 |
| #endif |
| , |
| "If not zero, instructs the target to set setrlimit(RLIMIT_AS) to " |
| "this number of megabytes. Some targets (e.g. if built with ASAN, " |
| "which can't run with RLIMIT_AS) may choose to ignore this flag. See " |
| "also --rss_limit_mb.") |
| CENTIPEDE_FLAG( |
| size_t, rss_limit_mb, 4096, |
| "If not zero, instructs the target to fail if RSS goes over this " |
| "number of megabytes and report an OOM. See also " |
| "--address_space_limit_mb. These two flags have somewhat different " |
| "meaning. --address_space_limit_mb does not allow the process to " |
| "grow the used address space beyond the limit. --rss_limit_mb runs a " |
| "background thread that monitors max RSS and also checks max RSS " |
| "after executing every input, so it may detect OOM late. However " |
| "--rss_limit_mb allows Centipede to *report* an OOM condition in " |
| "most cases, while --address_space_limit_mb will cause a crash that " |
| "may be hard to attribute to OOM.") |
| CENTIPEDE_FLAG( |
| size_t, stack_limit_kb, 0, |
| "If not zero, instructs the target to fail if stack usage goes over " |
| "this number of KiB.") |
| CENTIPEDE_FLAG( |
| size_t, timeout_per_input, 60, |
| "If not zero, the timeout in seconds for a single input. If an input " |
| "runs longer than this, the runner process will abort. Support may " |
| "vary depending on the runner.") |
| CENTIPEDE_FLAG( |
| size_t, timeout_per_batch, 0, |
| "If not zero, the collective timeout budget in seconds for a single " |
| "batch of inputs. Each input in a batch still has up to " |
| "--timeout_per_input seconds to finish, but the entire batch must " |
| "finish within --timeout_per_batch seconds. The default is computed " |
| "as a function of --timeout_per_input * --batch_size. Support may " |
| "vary depending on the runner.") |
| CENTIPEDE_FLAG(size_t, ignore_timeout_reports, false, |
| "If set, will ignore reporting timeouts as errors.") |
| CENTIPEDE_FLAG( |
| absl::Time, stop_at, absl::InfiniteFuture(), |
| "Stop fuzzing in all shards (--total_shards) at approximately this " |
| "time in ISO-8601/RFC-3339 format, e.g. 2023-04-06T23:35:02Z. " |
| "If a given shard is still running at that time, it will gracefully " |
| "wind down by letting the current batch of inputs to finish and then " |
| "exiting. A special value 'infinite-future' (the default) is " |
| "supported. Tip: `date` is useful for conversion of mostly free " |
| "format human readable date/time strings, e.g. " |
| "--stop_at=$(date --date='next Monday 6pm' --utc --iso-8601=seconds) " |
| ". Also see --stop_after. These two flags are mutually exclusive.") |
| CENTIPEDE_FLAG( |
| bool, fork_server, true, |
| "If true (default) tries to execute the target(s) via the fork " |
| "server, if supported by the target(s). Prepend the binary path with " |
| "'%f' to disable the fork server. --fork_server applies to binaries " |
| "passed via these flags: --binary, --extra_binaries, " |
| "--input_filter.") |
| CENTIPEDE_FLAG(bool, persistent_mode, true, |
| "If true (default), enables the persistent mode to run multiple " |
| "execute/mutate batches without exiting the process.") |
| CENTIPEDE_FLAG( |
| bool, full_sync, false, |
| "Perform a full corpus sync on startup. If true, feature sets and " |
| "corpora are read from all shards before fuzzing. This way fuzzing " |
| "starts with a full knowledge of the current state and will avoid " |
| "adding duplicating inputs. This however is very expensive when the " |
| "number of shards is very large.") |
| CENTIPEDE_FLAG( |
| bool, use_corpus_weights, true, |
| "If true, use weighted distribution when choosing the corpus element " |
| "to mutate. This flag is mostly for Centipede developers.") |
| CENTIPEDE_FLAG( |
| bool, use_coverage_frontier, false, |
| "If true, use coverage frontier when choosing the corpus element to " |
| "mutate. This flag is mostly for Centipede developers.") |
| CENTIPEDE_FLAG( |
| size_t, max_corpus_size, 100000, |
| "Indicates the number of inputs in the in-memory corpus after which" |
| "more aggressive pruning will be applied.") |
| CENTIPEDE_FLAG( |
| size_t, crossover_level, 50, |
| "Defines how much crossover is used during mutations. 0 means no " |
| "crossover, 100 means the most aggressive crossover. See " |
| "https://en.wikipedia.org/wiki/Crossover_(genetic_algorithm).") |
| CENTIPEDE_FLAG(bool, use_pc_features, true, |
| "When available from instrumentation, use features derived from " |
| "PCs.") |
| CENTIPEDE_FLAG( |
| size_t, path_level, 0, // Not ready for wide usage. |
| "When available from instrumentation, use features derived from " |
| "bounded execution paths. Be careful, may cause exponential feature " |
| "explosion. 0 means no path features. Values between 1 and 100 " |
| "define how aggressively to use the paths.") |
| CENTIPEDE_FLAG(bool, use_cmp_features, true, |
| "When available from instrumentation, use features derived from " |
| "instrumentation of CMP instructions.") |
| CENTIPEDE_FLAG( |
| size_t, callstack_level, 0, |
| "When available from instrumentation, use features derived from " |
| "observing the function call stacks. 0 means no callstack features." |
| "Values between 1 and 100 define how aggressively to use the " |
| "callstacks. Level N roughly corresponds to N call frames.") |
| CENTIPEDE_FLAG(bool, use_auto_dictionary, true, |
| "If true, use automatically-generated dictionary derived from " |
| "intercepting comparison instructions, memcmp, and similar.") |
| CENTIPEDE_FLAG(bool, use_dataflow_features, true, |
| "When available from instrumentation, use features derived from " |
| "data flows.") |
| CENTIPEDE_FLAG( |
| bool, use_counter_features, false, |
| "When available from instrumentation, use features derived from " |
| "counting the number of occurrences of a given PC. When enabled, " |
| "supersedes --use_pc_features.") |
| CENTIPEDE_FLAG(bool, use_pcpair_features, false, |
| "If true, PC pairs are used as additional synthetic features. " |
| "Experimental, use with care - it may explode the corpus.") |
| CENTIPEDE_FLAG( |
| uint64_t, user_feature_domain_mask, ~0UL, |
| "A bitmask indicating which user feature domains should be enabled. " |
| "A value of zero will disable all user features.") |
| CENTIPEDE_FLAG( |
| size_t, feature_frequency_threshold, 100, |
| "Internal flag. When a given feature is present in the corpus this " |
| "many times Centipede will stop recording it for future corpus " |
| "elements. Larger values will use more RAM but may improve corpus " |
| "weights. Valid values are 2 - 255.") |
| CENTIPEDE_FLAG(bool, require_pc_table, true, |
| "If true, Centipede will exit if the --pc_table is not found.") |
| CENTIPEDE_FLAG(bool, require_seeds, false, |
| "If true, Centipede will exit if no seed inputs are found.") |
| CENTIPEDE_FLAG( |
| int, telemetry_frequency, 0, |
| "Dumping frequency for intermediate telemetry files, i.e. coverage " |
| "report (workdir/coverage-report-BINARY.*.txt), corpus stats " |
| "(workdir/corpus-stats-*.json), etc. Positive value N means dump " |
| "every N batches. Negative N means start dumping after 2^N processed " |
| "batches with exponential 2x back-off (e.g. for " |
| "--telemetry_frequency=-5, dump on batches 32, 64, 128,...). Zero " |
| "means no telemetry. Note that the before-fuzzing and after-fuzzing " |
| "telemetry are always dumped.") |
| CENTIPEDE_FLAG(bool, print_runner_log, false, |
| "If true, runner logs are printed after every batch. Note that " |
| "crash logs are always printed regardless of this flag's value.") |
| // TODO(kcc): --distill and several others had better be dedicated binaries. |
| CENTIPEDE_FLAG( |
| bool, distill, false, |
| "Distill (minimize) the --total_shards input shards from --workdir " |
| "into --num_threads output shards. The input shards are randomly and " |
| "evenly divided between --num_threads concurrent distillation " |
| "threads to speed up processing. The threads share and update the " |
| "global coverage info as they go, so the output shards will never " |
| "have identical input/feature pairs (some intputs can still be " |
| "identical if a non-deterministic target produced different features " |
| "for identical inputs in the corpus). The features.* files are " |
| "looked up in a --workdir subdirectory that corresponds to " |
| "--coverage_binary and --binary_hash, if --binary_hash is provided; " |
| "if it is not provided, the actual hash of the --coverage_binary " |
| "file on disk is computed and used. Therefore, with an explicit " |
| "--binary_hash, --coverage_binary can be just the basename of the " |
| "actual target binary; without it, it must be the full path. " |
| "Each distillation thread writes a distilled corpus shard to " |
| "to <--workdir>/distilled-<--coverage_binary basename>.<index>.") |
| CENTIPEDE_FLAG( |
| size_t, log_features_shards, 0, |
| "The first --log_features_shards shards will log newly observed " |
| "features as symbols. In most cases you don't need this to be >= 2.") |
| CENTIPEDE_FLAG( |
| std::string, knobs_file, "", |
| "If not empty, knobs will be read from this (possibly remote) file." |
| " The feature is experimental, not yet fully functional.") |
| CENTIPEDE_FLAG( |
| std::string, corpus_to_files, "", |
| "Save the remote corpus from working to the given directory, one " |
| "file per corpus.") |
| CENTIPEDE_FLAG( |
| std::string, crashes_to_files, "", |
| "When set to a directory path, save the crashing reproducers and " |
| "metadata from the workdir to the given path: Each crash with `ID`" |
| "will be saved with file `ID.data` for the reproducer, `ID.desc` the " |
| "description, `ID.sig` the signature. If multiple crashes with the same ID " |
| "exist, only one crash will be saved.") |
| CENTIPEDE_FLAG( |
| std::string, corpus_from_files, "", |
| "Export a corpus from a local directory with one file per input into " |
| "the sharded remote corpus in workdir. Not recursive.") |
| CENTIPEDE_FLAG( |
| std::vector<std::string>, corpus_dir, {}, |
| "Comma-separated list of paths to local corpus dirs, with one file " |
| "per input. At startup, the files are exported into the corpus in " |
| "--workdir. While fuzzing, the new corpus elements are written to " |
| "the first dir if it is not empty. This makes it more convenient to " |
| "interop with libFuzzer corpora.") |
| CENTIPEDE_FLAG( |
| std::string, symbolizer_path, "llvm-symbolizer", |
| "Path to the symbolizer tool. By default, we use llvm-symbolizer " |
| "and assume it is in PATH.") |
| CENTIPEDE_FLAG( |
| std::string, objdump_path, "objdump", |
| "Path to the objdump tool. By default, we use the system objdump " |
| "and assume it is in PATH.") |
| CENTIPEDE_FLAG(std::string, runner_dl_path_suffix, "", |
| "If non-empty, this flag is passed to the Centipede runner. " |
| "It tells the runner that this dynamic library is instrumented " |
| "while the main binary is not. " |
| "The value could be the full path, like '/path/to/my.so' " |
| "or a suffix, like '/my.so' or 'my.so'." |
| "This flag is experimental and may be removed in future") |
| CENTIPEDE_FLAG( |
| std::string, input_filter, "", |
| "Path to a tool that filters bad inputs. The tool is invoked as " |
| "`input_filter INPUT_FILE` and should return 0 if the input is good " |
| "and non-0 otherwise. Ignored if empty. The --input_filter is " |
| "invoked only for inputs that are considered for addition to the " |
| "corpus.") |
| CENTIPEDE_FLAG( |
| std::vector<std::string>, dictionary, {}, |
| "A comma-separated list of paths to dictionary files. The dictionary " |
| "file is either in AFL/libFuzzer plain text format or in the binary " |
| "Centipede corpus file format. The flag is interpreted by " |
| "CentipedeCallbacks so its meaning may be different in custom " |
| "implementations of CentipedeCallbacks.") |
| CENTIPEDE_FLAG( |
| std::string, function_filter, "", |
| "A comma-separated list of functions that fuzzing needs to focus on. " |
| "If this list is non-empty, the fuzzer will mutate only those inputs " |
| "that trigger code in one of these functions.") |
| CENTIPEDE_FLAG( |
| std::string, for_each_blob, "", |
| "If non-empty, extracts individual blobs from the files given as " |
| "arguments, copies each blob to a temporary file, and applies this " |
| "command to that temporary file. %P is replaced with the temporary " |
| "file's path and %H is replaced with the blob's hash. Example:\n" |
| "$ centipede --for_each_blob='ls -l %P && echo %H' corpus.000000") |
| CENTIPEDE_FLAG( |
| std::string, experiment, "", |
| "A colon-separated list of values, each of which is a flag followed " |
| "by = and a comma-separated list of values. Example: " |
| "'foo=1,2,3:bar=10,20'. When non-empty, this flag is used to run an " |
| "A/B[/C/D...] experiment: different threads will set different " |
| "values of 'foo' and 'bar' and will run independent fuzzing " |
| "sessions. If more than one flag is given, all flag combinations are " |
| "tested. In example above: '--foo=1 --bar=10' ... " |
| "'--foo=3 --bar=20'. The number of threads should be multiple of the " |
| "number of flag combinations.") |
| CENTIPEDE_FLAG( |
| bool, analyze, false, |
| "If set, Centipede will read the corpora from the work dirs provided" |
| " as argv. If two corpora are provided, then analyze differences" |
| " between those corpora. If one corpus is provided, then save the" |
| " coverage report to a file within workdir with prefix" |
| " 'coverage-report-'.") |
| CENTIPEDE_FLAG(bool, exit_on_crash, false, |
| "If true, Centipede will exit on the first crash of the target.") |
| CENTIPEDE_FLAG(size_t, max_num_crash_reports, 5, |
| "report this many crashes per shard.") |
| CENTIPEDE_FLAG( |
| std::string, minimize_crash_file_path, "", |
| "If non-empty, a path to an input file that triggers a crash." |
| " Centipede will run the minimization loop and store smaller crashing" |
| " inputs in workdir/crashes.NNNNNN/, where NNNNNN is " |
| "--first_shard_index padded on the left with zeros. " |
| " --num_runs and --num_threads apply. " |
| " Assumes local workdir.") |
| CENTIPEDE_FLAG( |
| bool, batch_triage_suspect_only, false, |
| "If set, triage the crash on only the suspected input in a crashing " |
| "batch. Otherwise, triage on all the executed inputs") |
| CENTIPEDE_FLAG( |
| size_t, shmem_size_mb, 1024, |
| "Size of the shared memory regions used to communicate between the " |
| "ending and the runner.") |
| CENTIPEDE_FLAG( |
| bool, use_posix_shmem, |
| #ifdef __APPLE__ |
| true |
| #else |
| false |
| #endif |
| , |
| "[INTERNAL] When true, uses shm_open/shm_unlink instead of " |
| "memfd_create to allocate shared memory. You may want this if your " |
| "target doesn't have access to /proc/<arbitrary_pid> subdirs or the " |
| "memfd_create syscall is not supported.") |
| CENTIPEDE_FLAG( |
| bool, dry_run, false, |
| "Initializes as much of Centipede as possible without actually " |
| "running any fuzzing. Useful to validate the rest of the command " |
| "line, verify existence of all the input directories and files, " |
| "etc. Also useful in combination with --save_config or " |
| "--update_config to stop execution immediately after writing the " |
| "(updated) config file.") |
| CENTIPEDE_FLAG(bool, save_binary_info, false, |
| "Save the BinaryInfo from the fuzzing run within the working " |
| "directory.") |
| CENTIPEDE_FLAG( |
| bool, populate_binary_info, true, |
| "Get binary info from a coverage instrumented binary. This should " |
| "only be turned off when coverage is not based on instrumenting some " |
| "binary.") |
| CENTIPEDE_FLAG( |
| bool, riegeli, |
| #ifdef CENTIPEDE_DISABLE_RIEGELI |
| false |
| #else |
| true |
| #endif |
| , |
| "Use Riegeli file format (instead of the legacy bespoke encoding) " |
| "for storage") |
| CENTIPEDE_FLAG(bool, first_corpus_dir_output_only, false, |
| "If set, treat the first entry of `corpus_dir` as output-only. " |
| "For FuzzTest framework only, do not use from end-users.") |
| CENTIPEDE_FLAG(bool, load_shards_only, false, |
| "If set, load/merge shards without fuzzing new inputs. For " |
| "FuzzTest framework only, do not use from end-users.") |
| CENTIPEDE_FLAG( |
| bool, fuzztest_multi_test_mode_soon_to_be_removed, true, |
| "If set, operate on multiple fuzz tests queried from the binary if it is " |
| "using FuzzTest. This mode is going to be removed soon, and Centipede will " |
| "operate on only one fuzz test per invocation after that.") |
| CENTIPEDE_FLAG( |
| std::string, fuzztest_configuration, "", |
| "If set, deserializes the FuzzTest configuration from the value as a " |
| "base64url string instead of querying the configuration via runner " |
| "callbacks. For FuzzTest framework only, do not use from end-users.") |
| CENTIPEDE_FLAG( |
| bool, list_crash_ids, false, |
| "If set, lists the crash IDs of a single test of the binary to the " |
| "`crash_ids_file` with each crash ID in a single line. If there is no " |
| "crash for the test, the empty content will be written to the file. For " |
| "FuzzTest framework only, do not use from end-users.") |
| CENTIPEDE_FLAG(std::string, list_crash_ids_file, "", |
| "The path to list the crash IDs for `list_crash_ids`. For " |
| "FuzzTest framework only, do not use from end-users.") |
| CENTIPEDE_FLAG(std::string, crash_id, "", |
| "The crash ID used for `replay_crash` or `export_crash`. For " |
| "FuzzTest framework only, do not use from end-users.") |
| CENTIPEDE_FLAG(bool, replay_crash, false, |
| "If set, replay `crash_id` in the corpus database. For FuzzTest " |
| "framework only, do not use from end-users.") |
| CENTIPEDE_FLAG( |
| bool, export_crash, false, |
| "If set, export the input contents of `crash_id` from the corpus database. " |
| "For FuzzTest framework only, do not use from end-users.") |
| CENTIPEDE_FLAG( |
| std::string, export_crash_file, "", |
| "The path to export the input contents of `crash_id` for `export_crash`. " |
| "For FuzzTest framework only, do not use from end-users.") |
| CENTIPEDE_FLAG( |
| bool, report_crash_summary, true, |
| "If set, reports a summary of crashes found during fuzzing or replay." |
| ) |
