Override centipede default rss_limit_mb for Google/chromium targets

[aakallam]

#5207 updated this default only for reproduce() but changes the override location to also affect the the fuzz() and minimize_corpus() methods.

[g-ortuno]

How is this done for libfuzzer? I'm curious why the libfuzzer change was a single line but we need to duplicate this for all task types. Seems a bit brittle :/

[aakallam]

This matches what libFuzzer is doing by overriding the flag whenever the fuzzer arguments are built from the fuzzer-specific config and the default config:

clusterfuzz/src/clusterfuzz/_internal/bot/fuzzers/libFuzzer/fuzzer.py

Lines 32 to 65 in 9f0c774

	def get_arguments(fuzzer_path) -> options.FuzzerArguments:
	"""Get arguments for a given fuzz target."""
	arguments = options.FuzzerArguments()
	rss_limit_mb = None
	timeout = None
	fuzzer_options = options.get_fuzz_target_options(fuzzer_path)
	if fuzzer_options:
	arguments = fuzzer_options.get_engine_arguments('libfuzzer')
	rss_limit_mb = arguments.get('rss_limit_mb', constructor=int)
	timeout = arguments.get('timeout', constructor=int)
	if timeout is None:
	arguments[constants.TIMEOUT_FLAGNAME] = constants.DEFAULT_TIMEOUT_LIMIT
	if not rss_limit_mb and (utils.is_chromium() or
	utils.default_project_name() == 'google'):
	# TODO(metzman/alhijazi): Monitor if we are crashing the bots.
	arguments[constants.RSS_LIMIT_FLAGNAME] = 0
	elif not rss_limit_mb:
	arguments[constants.RSS_LIMIT_FLAGNAME] = constants.DEFAULT_RSS_LIMIT_MB
	else:
	# psutil gives the total amount of memory in bytes, but we're only dealing
	# with options that are counting memory space in MB, so we need to do the
	# conversion first.
	max_memory_limit_mb = (psutil.virtual_memory().total //
	(1 << 20)) - constants.MEMORY_OVERHEAD
	# Custom rss_limit_mb value shouldn't be greater than the actual memory
	# allocated on the machine.
	if rss_limit_mb > max_memory_limit_mb:
	arguments[constants.RSS_LIMIT_FLAGNAME] = max_memory_limit_mb
	return arguments

[g-ortuno]

Oh! I see, sorry, the commit message made me think that we changed the specific tasks to use the new value. LGTM!

[g-ortuno]

Thanks!