1 // SPDX-License-Identifier: GPL-2.0 2 /* Copyright (c) 2022 Google */ 3 4 #include "bpf_iter.h" 5 #include <bpf/bpf_helpers.h> 6 #include <bpf/bpf_tracing.h> 7 8 char _license[] SEC("license") = "GPL"; 9 int terminate_early = 0; 10 u64 terminal_cgroup = 0; 11 12 static inline u64 cgroup_id(struct cgroup *cgrp) 13 { 14 return cgrp->kn->id; 15 } 16 17 SEC("iter/cgroup") 18 int cgroup_id_printer(struct bpf_iter__cgroup *ctx) 19 { 20 struct seq_file *seq = ctx->meta->seq; 21 struct cgroup *cgrp = ctx->cgroup; 22 23 /* epilogue */ 24 if (cgrp == NULL) { 25 BPF_SEQ_PRINTF(seq, "epilogue\n"); 26 return 0; 27 } 28 29 /* prologue */ 30 if (ctx->meta->seq_num == 0) 31 BPF_SEQ_PRINTF(seq, "prologue\n"); 32 33 BPF_SEQ_PRINTF(seq, "%8llu\n", cgroup_id(cgrp)); 34 35 if (terminal_cgroup == cgroup_id(cgrp)) 36 return 1; 37 38 return terminate_early ? 1 : 0; 39 } 40