fae63bf13033adec80c7e6d73144a21ea3cfbc6d fuzz: Clarify that only SeedRandomStateForTest(SeedRand::ZEROS) is allowed (MarcoFalke)
fa18acb457e91cc0fa6b3640b6b55c6bc61572ee fuzz: Abort when using global PRNG without re-seed (MarcoFalke)
fa7809aeab838752af94c52977936a8c6555d315 fuzz: Add missing SeedRandomStateForTest(SeedRand::ZEROS) (MarcoFalke)
Pull request description:
This is the first step toward improving fuzz stability and determinism (https://github.com/bitcoin/bitcoin/issues/29018).
A fuzz target using the global test-only PRNG will now abort if the seed is re-used across fuzz inputs.
Also, temporarily add `SeedRandomStateForTest(SeedRand::ZEROS)` to all affected fuzz targets. This may slow down the libfuzzer leak detector, but it will disable itself after some time, or it can be disabled explicitly with `-detect_leaks=0`.
In a follow-up, each affected fuzz target can be stripped of the global random use and a local `RandomMixin` (or similar) can be added instead.
(Can be tested by removing any one of the re-seed calls and observing a fuzz abort)
ACKs for top commit:
hodlinator:
ACK fae63bf13033adec80c7e6d73144a21ea3cfbc6d
dergoegge:
utACK fae63bf13033adec80c7e6d73144a21ea3cfbc6d
marcofleon:
Tested ACK fae63bf13033adec80c7e6d73144a21ea3cfbc6d
Tree-SHA512: 4a0db69af7f715408edf4f8b08b44f34ce12ee2c79d33b336ad19a6e6bd079c4ff7c971af0a3efa428213407c1171f4e2837ec6a2577086c2f94cd15618a0892
a60d5702fd