governance: lower emergency vote threshold to 1/3 (#4440)

This changes the ratio in tally.rs emergency_pass() to 1/3 and also
updates any comments/docs referring to the previous 2/3 threshold. Note:
this will also affect `IBCFreeze` and `IBCUnfreeze`, so those have also
gotten easier to accomplish (seems fine for the same reasons, but wasn't
explicitly noted in the ticket). Closes #4389.

crates/core/component/governance/src/action_handler/validator_vote.rs

@@ -78,7 +78,7 @@ impl ActionHandler for ValidatorVote {
         tracing::debug!(validator_identity = %identity_key, proposal = %proposal, "cast validator vote");
         state.cast_validator_vote(*proposal, *identity_key, *vote, reason.clone());
 
-        // Emergency proposals are passed immediately after receiving +2/3 of
+        // Emergency proposals are passed immediately after receiving +1/3 of
         // validator votes. These include the eponymous `Emergency` proposal but
         // also `IbcFreeze` and `IbcUnfreeze`.
         let proposal_payload = state

crates/core/component/governance/src/proposal.rs

@@ -240,7 +240,7 @@ pub enum ProposalPayload {
         /// An optional commit hash for code that this proposal refers to.
         commit: Option<String>,
     },
-    /// An emergency proposal is immediately passed when 2/3 of all validators approve it, without
+    /// An emergency proposal is immediately passed when 1/3 of all validators approve it, without
     /// waiting for the voting period to conclude.
     Emergency {
         /// If `halt_chain == true`, then the chain will immediately halt when the proposal is

crates/core/component/governance/src/tally.rs

@@ -186,8 +186,8 @@ impl Tally {
         }
 
         // Now that we've checked for slash and quorum, we can just check to see if it should pass in
-        // the emergency condition of 2/3 majority of voting power
-        Ratio::new(self.yes, total_voting_power) > Ratio::new(2, 3)
+        // the emergency condition of 1/3 majority of voting power
+        Ratio::new(self.yes, total_voting_power) > Ratio::new(1, 3)
     }
 }
 

crates/proto/src/gen/penumbra.core.component.governance.v1.rs

@@ -628,7 +628,7 @@ pub mod proposal {
             )
         }
     }
-    /// An emergency proposal can be passed instantaneously by a 2/3 majority of validators, without
+    /// An emergency proposal can be passed instantaneously by a 1/3 majority of validators, without
     /// waiting for the voting period to expire.
     ///
     /// If the boolean `halt_chain` is set to `true`, then the chain will halt immediately when the

docs/guide/src/pcli/governance.md

@@ -132,7 +132,7 @@ may be included to specify these changes.
 #### Emergency Proposals
 
 Emergency proposals are meant for when immediate action is required to address a crisis, and
-conclude early as soon as a 2/3 majority of all active voting power votes yes.
+conclude early as soon as a 1/3 majority of all active voting power votes yes.
 
 Emergency proposals have the power to optionally halt the chain when passed. If this occurs,
 off-chain coordination between validators will be required to restart the chain.

docs/protocol/src/concepts/governance.md

@@ -22,14 +22,14 @@ proposals can reclaim their deposit).
 Proposals can either be normal or emergency proposals.  In either case, the
 voting period begins immediately, in the next block after the proposal has been
 committed to the chain.  Normal proposals have a fixed-length voting period,
-while emergency proposals are accepted as soon as a 2/3 majority of the stake is
+while emergency proposals are accepted as soon as a 1/3 majority of the stake is
 reached.
 
 Because validators provide default votes for their delegation pool, an emergency
 proposal can in principle be accepted immediately, without any input from
 delegators. This allows time-critical resolution of emergencies (e.g., deploying
-an 0day hotfix); the 2/3 majority of the stake required is already sufficient to
-arbitrarily rewrite the chain state.
+an 0day hotfix); a 1/3 + 1 plurality of the stake required is already sufficient to
+halt the chain.
 
 Proposals can also be withdrawn by their proposer prior to the end of the voting
 period.  This is done by creating a transaction with a `ProposalWithdraw`

docs/protocol/src/governance.md

@@ -73,7 +73,7 @@ may be included to specify these changes.
 #### Emergency Proposals
 
 Emergency proposals are meant for when immediate action is required to address a crisis, and
-conclude early as soon as a 2/3 majority of all active voting power votes yes.
+conclude early as soon as a 1/3 majority of all active voting power votes yes.
 
 Emergency proposals have the power to optionally halt the chain when passed. If this occurs,
 off-chain coordination between validators will be required to restart the chain.

proto/penumbra/penumbra/core/component/governance/v1/governance.proto

@@ -262,7 +262,7 @@ message Proposal {
     string commit = 1;
   }
 
-  // An emergency proposal can be passed instantaneously by a 2/3 majority of validators, without
+  // An emergency proposal can be passed instantaneously by a 1/3 majority of validators, without
   // waiting for the voting period to expire.
   //
   // If the boolean `halt_chain` is set to `true`, then the chain will halt immediately when the