run only 1 sanitized binary

[Ollrogge]

Currently, when fuzzing with multiple cores and ASAN enabled, we use the sanitized binary on all cores. This is unnecessary and degrades performance; instead, use the ASAN-compiled binary only on the first core.

Since we need two binaries for this, compile both a sanitized version and a not sanitized version if ASAN is enabled.

[louismerlin]

Super cool! Do you have any idea what the speedup is?

[louismerlin]

Can you please add some eprintln for "asan" before building the asan binary?

[Ollrogge]

Super cool! Do you have any idea what the speedup is?

No idea but I can / will measure :)

[Ollrogge]

Super cool! Do you have any idea what the speedup is?

Did some minimal benchmarking with the url example application. Running the fuzzer for 3 minutes I get:

1 core:

• ASan: cummulative speed 6.000 execs / sec | best coverage: 2.71 %
• No ASan: cummulative speed: 54016 execs/sec | best coverage: 8.92%

10 cores:

• 10 ASan: cummulative speed 22.767 execs/sec | best coverage: 4.30 %
• 1 ASan + 9 No ASan: cummulative speed 137.464 execs/sec | best coverage: 19.40%

So the speedup is quite drastic :)

Also added the eprintln.