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