@cryptotaxi247 / netdata-1 / commits / a59c44144

Improve EBPF cleanup (#21501)

Unlink shared memory and semaphore for eBPF cgroup during cleanup. Remove duplicate sem_post

Stelios Fragkakis committed Jan 4, 2026 at 20:46 UTC a59c441442a8281be77228efca1deb44310edfd5

2 files changed +9 -3

src/collectors/cgroups.plugin/cgroup-discovery.c

+9 -1

@@ -1055,6 +1055,12 @@ static void netdata_cgroup_ebpf_set_values(size_t length)

1055

1056 static void netdata_cgroup_ebpf_initialize_shm()

1057 {

1058 + // Unlink any existing shared memory and semaphore to start fresh.

1059 + // This prevents truncating memory that another process might be using.

1060 + // Existing mappings in other processes remain valid until they unmap.

1061 + (void) shm_unlink(NETDATA_SHARED_MEMORY_EBPF_CGROUP_NAME);

1062 + (void) sem_unlink(NETDATA_NAMED_SEMAPHORE_EBPF_CGROUP_NAME);

1063 +

1064 shm_fd_cgroup_ebpf = shm_open(NETDATA_SHARED_MEMORY_EBPF_CGROUP_NAME, O_CREAT | O_RDWR, 0660);

1065 if (shm_fd_cgroup_ebpf < 0) {

1066 collector_error("Cannot initialize shared memory used by cgroup and eBPF, integration won't happen.");

@@ -1093,13 +1099,14 @@ static void netdata_cgroup_ebpf_initialize_shm()

1099 end_init_shm:

1100 close(shm_fd_cgroup_ebpf);

1101 shm_fd_cgroup_ebpf = -1;

1096 - shm_unlink(NETDATA_SHARED_MEMORY_EBPF_CGROUP_NAME);

1102 + (void) shm_unlink(NETDATA_SHARED_MEMORY_EBPF_CGROUP_NAME);

1103 }

1104

1105 static void cgroup_cleanup_ebpf_integration()

1106 {

1107 if (shm_mutex_cgroup_ebpf != SEM_FAILED) {

1108 sem_close(shm_mutex_cgroup_ebpf);

1109 + (void) sem_unlink(NETDATA_NAMED_SEMAPHORE_EBPF_CGROUP_NAME);

1110 }

1111

1112 if (shm_cgroup_ebpf.header) {

@@ -1110,6 +1117,7 @@ static void cgroup_cleanup_ebpf_integration()

1117 if (shm_fd_cgroup_ebpf > 0) {

1118 close(shm_fd_cgroup_ebpf);

1119 }

1120 + (void) shm_unlink(NETDATA_SHARED_MEMORY_EBPF_CGROUP_NAME);

1121 }

1122

1123 // ----------------------------------------------------------------------------

src/collectors/ebpf.plugin/ebpf_cgroup.c

-2

@@ -310,8 +310,6 @@ void ebpf_parse_cgroup_shm_data()

310 previous,

311 shm_ebpf_cgroup.header->cgroup_root_count);

312 #endif

313 -

314 - sem_post(shm_sem_ebpf_cgroup);

313 }

314

315 // --------------------------------------------------------------------------------------------------------------------