Closed Bug 1526328 Opened 7 months ago Closed 6 months ago

Disable all Telemetry Recording in FUZZING builds


(Toolkit :: Telemetry, enhancement, P1)




Tracking Status
firefox67 --- fixed


(Reporter: decoder, Assigned: decoder)



(1 file)

Similar to bug 1207696, we have reasons to disable Telemetry in fuzzing builds. In particular, this code is even active when running single gtest-like targets with libFuzzer and causes a lot of intermittent coverage noise when running (any code running in a non-deterministic fashion in the background hurts coverage-guided fuzzing).

I will make a patch to disable any Telemetry recording in FUZZING_INTERFACE builds for now. We do have our own build-time switches for fuzzing, so this won't affect normal builds at all.

Alternatively, we could also disable it for all FUZZING builds, but that would mean that we don't test/exercise this code anymore in full browser fuzzing. The advantage would be less non-deterministic action going on in the background, the disadvantage would be missing potential bugs in the Telemetry code.

Jesse, what do you think?

Flags: needinfo?(jschwartzentruber)

I just realized that FUZZING_INTERFACES will also be defined in fuzzing builds for full-browser fuzzing, so we can't use that to disable Telemetry just for command line fuzzing.

Essentially we have two options:

  1. Disable the Telemetry code at build-time for all fuzzing


  1. Use a runtime check (e.g. getenv("FUZZER") != null) to detect that we are in a command line fuzzing setup that uses the fuzzing interface.

To be clear, we're talking about telemetry collection only, since we disable non-local network access while browser fuzzing.

I'd rather see it disabled for browser too. Any bugs we find in telemetry while fuzzing will likely be coincidental, and could just as easily be found while running the test suite.

Flags: needinfo?(jschwartzentruber)
Summary: Disable all Telemetry Recording in FUZZING_INTERFACE builds → Disable all Telemetry Recording in FUZZING builds
Pushed by
Disable Telemetry recording in FUZZING builds. r=janerik
Flags: needinfo?(choller)
Priority: -- → P1
Pushed by
Disable Telemetry recording in FUZZING builds. r=janerik
Closed: 6 months ago
Resolution: --- → FIXED
Target Milestone: --- → mozilla67
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