pkg:cgroups: fix parsing process cgroups for cgroupv1

The CgroupIDFromPID() function parses the process cgroup hierarchies obtained from /proc/pid/cgroup , it was not tested on cgroupv1 however it contains a bug, let's fix this. We want the cgroup hierarchy ID since that's the one that is exposed by the kernel not the cgroup subsystem index which is used in bpf to read cgroupv1 css indexes. Signed-off-by: Djalal Harouni <[email protected]>
cilium · Oct 30, 2024 · ae10919 · ae10919
1 parent dfaf03d
commit ae10919
Showing 1 changed file with 3 additions and 3 deletions.
diff --git a/pkg/cgroups/cgroups.go b/pkg/cgroups/cgroups.go
@@ -351,8 +351,8 @@ func setCgrpv1SubsystemIdx(controller *CgroupController) {
 }
 
 // GetCgrpHierarchyID() returns the ID of the Cgroup hierarchy
-// that is used to track processes. This is used for Cgroupv1 as for
-// Cgroupv2 we run in the default hierarchy.
+// that is used to track processes. This is used mostly for
+// Cgroupv1 as for Cgroupv2 we run in the default hierarchy.
 func GetCgrpHierarchyID() uint32 {
 	return cgrpHierarchy
 }
@@ -807,7 +807,7 @@ func CgroupIDFromPID(pid uint32) (uint64, error) {
 	case CGROUP_LEGACY, CGROUP_HYBRID:
 		pathFunc = func(line string) (bool, string) {
 			// TODO: test the cgroup v1 implementation
-			v1Prefix := fmt.Sprintf("%d:%s:", GetCgrpv1SubsystemIdx(), GetCgrpControllerName())
+			v1Prefix := fmt.Sprintf("%d:%s:", GetCgrpHierarchyID(), GetCgrpControllerName())
 			if !strings.HasPrefix(line, v1Prefix) {
 				return false, ""
 			}