From 8d698286b8bfc948fd99e4d15a772ed68fb26538 Mon Sep 17 00:00:00 2001
From: Maryam Tahhan <mtahhan@redhat.com>
Date: Mon, 26 Aug 2024 07:33:15 -0400
Subject: [PATCH] chore: introduce locking to pkg/cgroups

Signed-off-by: Maryam Tahhan <mtahhan@redhat.com>
---
 pkg/cgroup/resolve_container.go | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/pkg/cgroup/resolve_container.go b/pkg/cgroup/resolve_container.go
index a0d28e77d7..f1eacbddaf 100644
--- a/pkg/cgroup/resolve_container.go
+++ b/pkg/cgroup/resolve_container.go
@@ -54,6 +54,7 @@ type cache struct {
 	containerIDCache           map[uint64]string
 	containerIDToContainerInfo map[string]*ContainerInfo
 	cGroupIDToPath             map[uint64]string
+	mu                         sync.RWMutex
 }
 
 func Init() (*[]corev1.Pod, error) {
@@ -119,12 +120,15 @@ func GetContainerInfo(cGroupID, pid uint64, withCGroupID bool) (*ContainerInfo,
 		return info, err
 	}
 
+	instance.mu.Lock()
+	defer instance.mu.Unlock()
 	if i, ok := instance.containerIDToContainerInfo[containerID]; ok {
 		return i, nil
 	} else {
 		info.ContainerID = containerID
 		instance.containerIDToContainerInfo[containerID] = info
 	}
+
 	return instance.containerIDToContainerInfo[containerID], nil
 }
 
@@ -151,15 +155,20 @@ func getContainerIDFromPath(cGroupID, pid uint64, withCGroupID bool) (string, er
 // AddContainerIDToCache add the container id to cache using the pid as the key
 func AddContainerIDToCache(pid uint64, containerID string) {
 	ensureCacheInitialized()
+	instance.mu.Lock()
+	defer instance.mu.Unlock()
 	instance.containerIDCache[pid] = containerID
 }
 
 // GetContainerIDFromPID find the container ID using the process PID
 func GetContainerIDFromPID(pid uint64) (string, error) {
 	ensureCacheInitialized()
+	instance.mu.RLock()
 	if p, ok := instance.containerIDCache[pid]; ok {
+		instance.mu.RUnlock()
 		return p, nil
 	}
+	instance.mu.RUnlock()
 
 	var err error
 	var path string
@@ -169,6 +178,7 @@ func GetContainerIDFromPID(pid uint64) (string, error) {
 
 	containerID, err := extractPodContainerIDfromPath(path)
 	AddContainerIDToCache(pid, containerID)
+
 	return instance.containerIDCache[pid], err
 }
 
@@ -196,9 +206,12 @@ func getPathFromPID(searchPath string, pid uint64) (string, error) {
 }
 
 func getContainerIDFromcGroupID(cGroupID uint64) (string, error) {
+	instance.mu.RLock()
 	if id, ok := instance.containerIDCache[cGroupID]; ok {
+		instance.mu.RUnlock()
 		return id, nil
 	}
+	instance.mu.RUnlock()
 
 	var err error
 	var path string
@@ -208,12 +221,15 @@ func getContainerIDFromcGroupID(cGroupID uint64) (string, error) {
 
 	containerID, err := extractPodContainerIDfromPath(path)
 	AddContainerIDToCache(cGroupID, containerID)
+
 	return instance.containerIDCache[cGroupID], err
 }
 
 // getPathFromcGroupID uses cgroupfs to get cgroup path from id
 // it needs cgroup v2 (per https://github.com/iovisor/bpftrace/issues/950) and kernel 4.18+ (https://github.com/torvalds/linux/commit/bf6fa2c893c5237b48569a13fa3c673041430b6c)
 func getPathFromcGroupID(cgroupID uint64) (string, error) {
+	instance.mu.Lock()
+	defer instance.mu.Unlock()
 	if p, ok := instance.cGroupIDToPath[cgroupID]; ok {
 		return p, nil
 	}
@@ -278,6 +294,9 @@ func extractPodContainerIDfromPathWithCgroup(path string) (string, error) {
 func getAliveContainers(pods *[]corev1.Pod) map[string]bool {
 	aliveContainers := make(map[string]bool)
 
+	instance.mu.Lock()
+	defer instance.mu.Unlock()
+
 	for i := 0; i < len(*pods); i++ {
 		statuses := (*pods)[i].Status.InitContainerStatuses
 		for j := 0; j < len(statuses); j++ {