fix: removed potential sources of non-determinism in upgrades (backport #10189)

CHANGELOG.md

@@ -71,6 +71,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 ### Bug Fixes
 
 * [\#9965](https://github.com/cosmos/cosmos-sdk/pull/9965) Fixed `simd version` command output to report the right release tag.
+* (x/upgrade) [\#10189](https://github.com/cosmos/cosmos-sdk/issues/10189) Removed potential sources of non-determinism in upgrades.
 
 ### Client Breaking Changes
 

store/rootmulti/store.go

@@ -190,7 +190,22 @@ func (rs *Store) loadVersion(ver int64, upgrades *types.StoreUpgrades) error {
 	// load each Store (note this doesn't panic on unmounted keys now)
 	var newStores = make(map[types.StoreKey]types.CommitKVStore)
 
-	for key, storeParams := range rs.storesParams {
+	storesKeys := make([]types.StoreKey, 0, len(rs.storesParams))
+
+	for key := range rs.storesParams {
+		storesKeys = append(storesKeys, key)
+	}
+	if upgrades != nil {
+		// deterministic iteration order for upgrades
+		// (as the underlying store may change and
+		// upgrades make store changes where the execution order may matter)
+		sort.Slice(storesKeys, func(i, j int) bool {
+			return storesKeys[i].Name() < storesKeys[j].Name()
+		})
+	}
+
+	for _, key := range storesKeys {
+		storeParams := rs.storesParams[key]
 		commitID := rs.getCommitID(infos, key.Name())
 
 		// If it has been added, set the initial version

types/module/module.go

@@ -30,6 +30,7 @@ package module
 
 import (
 	"encoding/json"
+	"sort"
 
 	"github.com/gorilla/mux"
 	"github.com/grpc-ecosystem/grpc-gateway/runtime"
@@ -389,7 +390,18 @@ func (m Manager) RunMigrations(ctx sdk.Context, cfg Configurator, fromVM Version
 	}
 
 	updatedVM := make(VersionMap)
-	for moduleName, module := range m.Modules {
+	// for deterministic iteration order
+	// (as some migrations depend on other modules
+	// and the order of executing migrations matters)
+	// TODO: make the order user-configurable?
+	sortedModNames := make([]string, 0, len(m.Modules))
+	for key := range m.Modules {
+		sortedModNames = append(sortedModNames, key)
+	}
+	sort.Strings(sortedModNames)
+
+	for _, moduleName := range sortedModNames {
+		module := m.Modules[moduleName]
 		fromVersion, exists := fromVM[moduleName]
 		toVersion := module.ConsensusVersion()
 

x/upgrade/keeper/keeper.go

@@ -7,6 +7,7 @@ import (
 	"os"
 	"path"
 	"path/filepath"
+	"sort"
 
 	"github.com/tendermint/tendermint/libs/log"
 	tmos "github.com/tendermint/tendermint/libs/os"
@@ -84,7 +85,18 @@ func (k Keeper) SetModuleVersionMap(ctx sdk.Context, vm module.VersionMap) {
 	if len(vm) > 0 {
 		store := ctx.KVStore(k.storeKey)
 		versionStore := prefix.NewStore(store, []byte{types.VersionMapByte})
-		for modName, ver := range vm {
+		// Even though the underlying store (cachekv) store is sorted, we still
+		// prefer a deterministic iteration order of the map, to avoid undesired
+		// surprises if we ever change stores.
+		sortedModNames := make([]string, 0, len(vm))
+
+		for key := range vm {
+			sortedModNames = append(sortedModNames, key)
+		}
+		sort.Strings(sortedModNames)
+
+		for _, modName := range sortedModNames {
+			ver := vm[modName]
 			nameBytes := []byte(modName)
 			verBytes := make([]byte, 8)
 			binary.BigEndian.PutUint64(verBytes, ver)