Consider adding evidence parameters to the paramfilter

[evan-forbes]

We've noticed that there are potentially 3 values that are currently modifiable via token voting that we might not want to be changed. These are the two evidence paramters, evidence.MaxAgeNumBlocks and evidence.MaxAgeDuration, along with the mint module's mint.BondDenom (the denomination sent to the distribution module's account)

[evan-forbes]

cc @adlerjohn and @liamsi

simlar to our latest last minute change, while technically consensus breaking if no one successfully changes these values in governance we should be clear to update by simply upgrading

[rootulp]

I'm still investigating if governance can modify any of these 3 params but it doesn't look like it.

• I thinkmint.BondDenom is a genesis config and isn't a governance modifiable param. The x/mint module doesn't appear to use the params module (b/c no param subspace is provided here).
• For the evidence parameters, this file is mostly empty. Cosmos SDK docs claim: "The evidence module does not contain any parameters."

[rootulp]

The evidence parameters are a subset of the consensus parameters. cosmos/cosmos-sdk#6197 and cosmos/cosmos-sdk#5952 leads me to think that consensus parameters are modifiable through abci.EndBlocker but I don't think they're modifiable through the governance module. The behavior of modifying consensus params isn't documented in the gov docs and I couldn't find references to consensus params or evidence params in the x/gov module so they still seem non governance modifiable.

Update: created cosmos/cosmos-sdk#17630

[rootulp]

Update: we're not including this in the v1.x release of celestia-app. We do intend on including it in a subsequent breaking change.

[rootulp]

I'm not sure why the OP calls out those 3 params. IMO all the params that are currently governance modifiable should be made governance unmodifiable. Instead we should determine the values for those params off-chain via rough consensus and then update them (if necessary) via hard-forks.

[rootulp]

Update: moving any param from governance modifiable to unmodifiable requires a CIP. CIP-16 proposes making the two evidence params gov unmodifiable so I think we can close this issue as won't do until that CIP has reached Final status.