[CWS] remove interface{} and map of maps in invalid discarder check (…

…#17855)

* remove `interface{}` from `isInvalidDiscarder`

* remove `interface{}` from `InvalidDiscarders`

* remove map of map in invalid discarder check

pkg/security/probe/discarders.go

@@ -81,15 +81,15 @@ var (
 )
 
 var (
-	dentryInvalidDiscarder = []interface{}{""}
+	dentryInvalidDiscarder = []string{""}
 	eventZeroDiscarder     = &model.Event{
 		FieldHandlers:    &model.DefaultFieldHandlers{},
 		ContainerContext: &model.ContainerContext{},
 	}
 )
 
 // InvalidDiscarders exposes list of values that are not discarders
-var InvalidDiscarders = map[eval.Field][]interface{}{
+var InvalidDiscarders = map[eval.Field][]string{
 	"open.file.path":               dentryInvalidDiscarder,
 	"unlink.file.path":             dentryInvalidDiscarder,
 	"chmod.file.path":              dentryInvalidDiscarder,
@@ -518,27 +518,23 @@ func filenameDiscarderWrapper(eventType model.EventType, getter inodeEventGetter
 }
 
 // isInvalidDiscarder returns whether the given value is a valid discarder for the given field
-func isInvalidDiscarder(field eval.Field, value interface{}) bool {
-	values, exists := invalidDiscarders[field]
-	if !exists {
-		return false
-	}
-
-	return values[value]
+func isInvalidDiscarder(field eval.Field, value string) bool {
+	return invalidDiscarders[invalidDiscarderEntry{
+		field: field,
+		value: value,
+	}]
 }
 
 // rearrange invalid discarders for fast lookup
-func createInvalidDiscardersCache() map[eval.Field]map[interface{}]bool {
-	invalidDiscarders := make(map[eval.Field]map[interface{}]bool)
+func createInvalidDiscardersCache() map[invalidDiscarderEntry]bool {
+	invalidDiscarders := make(map[invalidDiscarderEntry]bool)
 
 	for field, values := range InvalidDiscarders {
-		ivalues := invalidDiscarders[field]
-		if ivalues == nil {
-			ivalues = make(map[interface{}]bool)
-			invalidDiscarders[field] = ivalues
-		}
 		for _, value := range values {
-			ivalues[value] = true
+			invalidDiscarders[invalidDiscarderEntry{
+				field: field,
+				value: value,
+			}] = true
 		}
 	}
 
@@ -700,7 +696,12 @@ func dumpDiscarders(resolver *dentry.Resolver, pidMap, inodeMap, statsFB, statsB
 	return dump, nil
 }
 
-var invalidDiscarders map[eval.Field]map[interface{}]bool
+type invalidDiscarderEntry struct {
+	field eval.Field
+	value string
+}
+
+var invalidDiscarders map[invalidDiscarderEntry]bool
 
 func init() {
 	invalidDiscarders = createInvalidDiscardersCache()