On 201229 1240, Qiuhao Li wrote: > We spend much time waiting for the timeout program during the minimization > process until it passes a time limit. This patch hacks the CLOSED (indicates > the redirection file closed) notification in QTest's output if it doesn't > crash. > > Test with quadrupled trace input at: > https://bugs.launchpad.net/qemu/+bug/1890333/comments/1 > > Original version: > real 1m37.246s > user 0m13.069s > sys 0m8.399s > > Refined version: > real 0m45.904s > user 0m16.874s > sys 0m10.042s > > Signed-off-by: Qiuhao Li <qiuhao...@outlook.com> > --- > scripts/oss-fuzz/minimize_qtest_trace.py | 41 ++++++++++++++++-------- > 1 file changed, 28 insertions(+), 13 deletions(-) > > diff --git a/scripts/oss-fuzz/minimize_qtest_trace.py > b/scripts/oss-fuzz/minimize_qtest_trace.py > index 5e405a0d5f..aa69c7963e 100755 > --- a/scripts/oss-fuzz/minimize_qtest_trace.py > +++ b/scripts/oss-fuzz/minimize_qtest_trace.py > @@ -29,30 +29,46 @@ whether the crash occred. Optionally, manually set a > string that idenitifes the > crash by setting CRASH_TOKEN= > """.format((sys.argv[0]))) > > +deduplication_note = """\n\ > +Note: While trimming the input, sometimes the mutated trace triggers a > different > +crash output but indicates the same bug. Under this situation, our minimizer > is > +incapable of recognizing and stopped from removing it. In the future, we may > +use a more sophisticated crash case deduplication method. > +\n""" > + > def check_if_trace_crashes(trace, path): > - global CRASH_TOKEN > with open(path, "w") as tracefile: > tracefile.write("".join(trace)) > > - rc = subprocess.Popen("timeout -s 9 {timeout}s {qemu_path} {qemu_args} > 2>&1\ > + proc = subprocess.Popen("timeout {timeout}s {qemu_path} {qemu_args} 2>&1\
Why remove the -s 9 here? I ran into a case where the minimizer got stuck on one iteration. Adding back "sigkill" to the timeout can be a safety net to catch those bad cases. -Alex > < {trace_path}".format(timeout=TIMEOUT, > qemu_path=QEMU_PATH, > qemu_args=QEMU_ARGS, > trace_path=path), > shell=True, > stdin=subprocess.PIPE, > - stdout=subprocess.PIPE) > - stdo = rc.communicate()[0] > - output = stdo.decode('unicode_escape') > - if rc.returncode == 137: # Timed Out > - return False > - if len(output.splitlines()) < 2: > - return False > - > + stdout=subprocess.PIPE, > + encoding="utf-8") > + global CRASH_TOKEN > if CRASH_TOKEN is None: > - CRASH_TOKEN = output.splitlines()[-2] > + try: > + outs, _ = proc.communicate(timeout=5) > + CRASH_TOKEN = outs.splitlines()[-2] > + except subprocess.TimeoutExpired: > + print("subprocess.TimeoutExpired") > + return False > + print("Identifying Crashes by this string: {}".format(CRASH_TOKEN)) > + global deduplication_note > + print(deduplication_note) > + return True > > - return CRASH_TOKEN in output > + for line in iter(proc.stdout.readline, b''): > + if "CLOSED" in line: > + return False > + if CRASH_TOKEN in line: > + return True > + > + return False > > > def minimize_trace(inpath, outpath): > @@ -66,7 +82,6 @@ def minimize_trace(inpath, outpath): > print("Crashed in {} seconds".format(end-start)) > TIMEOUT = (end-start)*5 > print("Setting the timeout for {} seconds".format(TIMEOUT)) > - print("Identifying Crashes by this string: {}".format(CRASH_TOKEN)) > > i = 0 > newtrace = trace[:] > -- > 2.25.1 >