1551355 - Migrate profiler timestamps to TimeStamp::NowUnfuzzed()

Status: RESOLVED FIXED

(Core :: Gecko Profiler, enhancement, P3)

Description

[Denis Palmeiro [:denispal]]

To avoid any surprises when FuzzyFox is enabled, we should migrate over to use NowUnfuzzed() instead of Now().

Comment 1

[Gerald Squelart (he/him) (not at Mozilla since 2022-09-15)]

Thank you Denis for opening this bug.

Since we record these soon-to-be-unfuzzed times in some markers that are exposed in profiles, should we add an option to re-fuzz timers when sharing profiles?
(Like we already offer options to remove URLs, screenshots, etc., to protect privacy -- Click on "Publish..." button at top-right of just-captured profiles.)

Comment 2

[Denis Palmeiro [:denispal]]

Attachment: Use TimeStamp::NowUnfuzzed() instead of TimeStamp::Now() during gecko profiling

The profiler will requrie non-fuzzed timers for accuracy. Making the switch early will avoid surprises when FuzzyFox is enabled.

Comment 3

[Denis Palmeiro [:denispal]]

(In reply to Gerald Squelart [:gerald] from comment #1)

Thank you Denis for opening this bug.

Since we record these soon-to-be-unfuzzed times in some markers that are exposed in profiles, should we add an option to re-fuzz timers when sharing profiles?
(Like we already offer options to remove URLs, screenshots, etc., to protect privacy -- Click on "Publish..." button at top-right of just-captured profiles.)

That's an interesting question! I think if we re-fuzz the timestamps then the uploaded profiles may become much less valuable and even potentially useless in many cases?

Comment 4

[Julien Wajsberg [:julienw]]

I think that with fuzzing timestamps the main threat we want to protect our users about is the timing attacks running in the browser. I don't think that fuzzing when sharing would help this, and I can't think of another thread scenario where this would help. What do you think?

Comment 5

[Markus Stange [:mstange]]

I agree, the attack scenario which fuzzing helps with is not relevant for profile sharing. Timestamps are fuzzed in order to avoid leaking data about origin B to a website of origin A. If the owner of origin A can coerce the victim into capturing a profile and sharing it with them, all bets are off anyway because profiles already contain lots of data about things happening on other origins.

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/61b74216fec0
Use TimeStamp::NowUnfuzzed() instead of TimeStamp::Now() during gecko profiling r=mstange

Comment 7

[Noemi Erli[:noemi_erli]]

https://hg.mozilla.org/mozilla-central/rev/61b74216fec0