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

File Facts

System

Linux kernel

Corpus path

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

Extension

.c

Size

757 bytes

Lines

41

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.
• Uses kernel synchronization; read lock ordering, sleepability, and interrupt context assumptions before translating.
• Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.

Dependency Surface

• linux/ptrace.h
• linux/bpf.h
• bpf/bpf_helpers.h
• bpf/bpf_tracing.h

Detected Declarations

• struct hmap_elem
• function new_handle_kprobe

Annotated Snippet

struct hmap_elem {
	struct bpf_spin_lock lock;
	int var[VAR_NUM];
};

struct {
	__uint(type, BPF_MAP_TYPE_HASH);
	__uint(max_entries, 1);
	__type(key, __u32);
	__type(value, struct hmap_elem);
} hash_map SEC(".maps");

SEC("freplace/handle_kprobe")
int new_handle_kprobe(struct pt_regs *ctx)
{
	struct hmap_elem *val;
	int key = 0;

	val = bpf_map_lookup_elem(&hash_map, &key);
	if (!val)
		return 1;
	/* spin_lock in hash map */
	bpf_spin_lock(&val->lock);
	val->var[0] = 99;
	bpf_spin_unlock(&val->lock);

	return 0;
}

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

Annotation

• Immediate include surface: `linux/ptrace.h`, `linux/bpf.h`, `bpf/bpf_helpers.h`, `bpf/bpf_tracing.h`.
• Detected declarations: `struct hmap_elem`, `function new_handle_kprobe`.
• Atlas domain: Support Tooling And Documentation / tools.
• Implementation status: source implementation candidate.
• Synchronization appears in or near this file; preserve lock ordering, sleepability, and interrupt-context constraints.

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.