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

File Facts

System

Linux kernel

Corpus path

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

Extension

.c

Size

956 bytes

Lines

47

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

• vmlinux.h
• errno.h
• bpf/bpf_helpers.h
• bpf/bpf_tracing.h

Detected Declarations

• function BPF_PROG

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0

/*
 * Copyright (C) 2022 Huawei Technologies Duesseldorf GmbH
 *
 * Author: Roberto Sassu <roberto.sassu@huawei.com>
 */

#include "vmlinux.h"
#include <errno.h>
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_tracing.h>

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

__u32 monitored_pid;
__s32 key_serial;
__u32 key_id;
__u64 flags;

extern struct bpf_key *bpf_lookup_user_key(__s32 serial, __u64 flags) __ksym;
extern struct bpf_key *bpf_lookup_system_key(__u64 id) __ksym;
extern void bpf_key_put(struct bpf_key *key) __ksym;

SEC("lsm.s/bpf")
int BPF_PROG(bpf, int cmd, union bpf_attr *attr, unsigned int size, bool kernel)
{
	struct bpf_key *bkey;
	__u32 pid;

	pid = bpf_get_current_pid_tgid() >> 32;
	if (pid != monitored_pid)
		return 0;

	if (key_serial)
		bkey = bpf_lookup_user_key(key_serial, flags);
	else
		bkey = bpf_lookup_system_key(key_id);

	if (!bkey)
		return -ENOENT;

	bpf_key_put(bkey);

	return 0;
}

Annotation

• Immediate include surface: `vmlinux.h`, `errno.h`, `bpf/bpf_helpers.h`, `bpf/bpf_tracing.h`.
• Detected declarations: `function BPF_PROG`.
• 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.