pkg/subsystem: extract subsystems from a crash list

For now, let's use a straightforward approach:
1) Extract all subsystems for each guilty path and syz reproducer.
2) If there are both parents and children in the list, remove parents.
3) Count the remaining subsystems.
4) Pick the ones that appear most often.

1 files changed, 1 insertions, 16 deletions

diff --git a/pkg/subsystem/linux/parents.go b/pkg/subsystem/linux/parents.go
index 40ba10b7f..5c66782c1 100644
--- a/pkg/subsystem/linux/parents.go
+++ b/pkg/subsystem/linux/parents.go
@@ -35,8 +35,7 @@ func transitiveReduction(list []*entity.Subsystem) {
 	for _, s := range list {
 		removeParents := map[*entity.Subsystem]bool{}
 		for _, p := range s.Parents {
-			reachable := reachableParents(p)
-			for otherP := range reachable {
+			for otherP := range p.ReachableParents() {
 				removeParents[otherP] = true
 			}
 		}
@@ -50,20 +49,6 @@ func transitiveReduction(list []*entity.Subsystem) {
 	}
 }
 
-// reachableParents lists all entity.Subsystem entries reachable from the given one.
-func reachableParents(start *entity.Subsystem) map[*entity.Subsystem]bool {
-	ret := make(map[*entity.Subsystem]bool)
-	var dfs func(node *entity.Subsystem)
-	dfs = func(node *entity.Subsystem) {
-		for _, p := range node.Parents {
-			ret[p] = true
-			dfs(p)
-		}
-	}
-	dfs(start)
-	return ret
-}
-
 // loopsExist is a helper method that verifies that the resulting graph has no loops.
 func loopsExist(list []*entity.Subsystem) bool {
 	type graphNode struct {