tools/testing/selftests/bpf/progs/test_cgroup_link.c

File Facts

System

Linux kernel

Corpus path

tools/testing/selftests/bpf/progs/test_cgroup_link.c

Extension

.c

Size

422 bytes

Lines

25

Domain

Support Tooling And Documentation

Bucket

tools

Inferred role

Support Tooling And Documentation: implementation source

Status

source implementation candidate

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

• Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.
• Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.

Dependency Surface

• linux/bpf.h
• bpf/bpf_helpers.h

Detected Declarations

• function egress
• function egress_alt

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0
// Copyright (c) 2020 Facebook
#include <linux/bpf.h>
#include <bpf/bpf_helpers.h>

int calls = 0;
int alt_calls = 0;

SEC("cgroup_skb/egress")
int egress(struct __sk_buff *skb)
{
	__sync_fetch_and_add(&calls, 1);
	return 1;
}

SEC("cgroup_skb/egress")
int egress_alt(struct __sk_buff *skb)
{
	__sync_fetch_and_add(&alt_calls, 1);
	return 1;
}

char _license[] SEC("license") = "GPL";

Annotation

• Immediate include surface: `linux/bpf.h`, `bpf/bpf_helpers.h`.
• Detected declarations: `function egress`, `function egress_alt`.
• Atlas domain: Support Tooling And Documentation / tools.
• Implementation status: source implementation candidate.

Implementation Notes

• This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
• Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
• Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.