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

Source file repositories/reference/linux-study-clean/tools/testing/selftests/bpf/progs/test_map_in_map.c

File Facts

System
Linux kernel
Corpus path
tools/testing/selftests/bpf/progs/test_map_in_map.c
Extension
.c
Size
1679 bytes
Lines
77
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.

Dependency Surface

Detected Declarations

Annotated Snippet

struct perf_event_array {
	__uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY);
	__type(key, __u32);
	__type(value, __u32);
} inner_map0 SEC(".maps");

struct {
	__uint(type, BPF_MAP_TYPE_ARRAY_OF_MAPS);
	__uint(max_entries, 1);
	__type(key, __u32);
	__array(values, struct perf_event_array);
} mim_array_pe SEC(".maps") = {
	.values = {&inner_map0}};

struct {
	__uint(type, BPF_MAP_TYPE_HASH_OF_MAPS);
	__uint(max_entries, 1);
	__type(key, __u32);
	__array(values, struct perf_event_array);
} mim_hash_pe SEC(".maps") = {
	.values = {&inner_map0}};

SEC("xdp")
int xdp_mimtest0(struct xdp_md *ctx)
{
	int value = 123;
	int *value_p;
	int key = 0;
	void *map;

	map = bpf_map_lookup_elem(&mim_array, &key);
	if (!map)
		return XDP_DROP;

	bpf_map_update_elem(map, &key, &value, 0);
	value_p = bpf_map_lookup_elem(map, &key);
	if (!value_p || *value_p != 123)
		return XDP_DROP;

	map = bpf_map_lookup_elem(&mim_hash, &key);
	if (!map)
		return XDP_DROP;

	bpf_map_update_elem(map, &key, &value, 0);

	return XDP_PASS;
}

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

Annotation

Implementation Notes