tools/testing/selftests/bpf/prog_tests/map_in_map.c

Source file repositories/reference/linux-study-clean/tools/testing/selftests/bpf/prog_tests/map_in_map.c

File Facts

System
Linux kernel
Corpus path
tools/testing/selftests/bpf/prog_tests/map_in_map.c
Extension
.c
Size
6736 bytes
Lines
272
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 thread_ctx {
	pthread_barrier_t barrier;
	int outer_map_fd;
	int start, abort;
	int loop, err;
};

static int wait_for_start_or_abort(struct thread_ctx *ctx)
{
	while (!ctx->start && !ctx->abort)
		usleep(1);
	return ctx->abort ? -1 : 0;
}

static void *update_map_fn(void *data)
{
	struct thread_ctx *ctx = data;
	int loop = ctx->loop, err = 0;

	if (wait_for_start_or_abort(ctx) < 0)
		return NULL;
	pthread_barrier_wait(&ctx->barrier);

	while (loop-- > 0) {
		int fd, zero = 0;

		fd = bpf_map_create(BPF_MAP_TYPE_ARRAY, NULL, 4, 4, 1, NULL);
		if (fd < 0) {
			err |= 1;
			pthread_barrier_wait(&ctx->barrier);
			continue;
		}

		/* Remove the old inner map */
		if (bpf_map_update_elem(ctx->outer_map_fd, &zero, &fd, 0) < 0)
			err |= 2;
		close(fd);
		pthread_barrier_wait(&ctx->barrier);
	}

	ctx->err = err;

	return NULL;
}

static void *access_map_fn(void *data)
{
	struct thread_ctx *ctx = data;
	int loop = ctx->loop;

	if (wait_for_start_or_abort(ctx) < 0)
		return NULL;
	pthread_barrier_wait(&ctx->barrier);

	while (loop-- > 0) {
		/* Access the old inner map */
		syscall(SYS_getpgid);
		pthread_barrier_wait(&ctx->barrier);
	}

	return NULL;
}

static void test_map_in_map_access(const char *prog_name, const char *map_name)
{
	struct access_map_in_map *skel;
	struct bpf_map *outer_map;
	struct bpf_program *prog;
	struct thread_ctx ctx;
	pthread_t tid[2];
	int err;

	skel = access_map_in_map__open();
	if (!ASSERT_OK_PTR(skel, "access_map_in_map open"))
		return;

	prog = bpf_object__find_program_by_name(skel->obj, prog_name);
	if (!ASSERT_OK_PTR(prog, "find program"))
		goto out;
	bpf_program__set_autoload(prog, true);

	outer_map = bpf_object__find_map_by_name(skel->obj, map_name);
	if (!ASSERT_OK_PTR(outer_map, "find map"))
		goto out;

	err = access_map_in_map__load(skel);
	if (!ASSERT_OK(err, "access_map_in_map load"))
		goto out;

	err = access_map_in_map__attach(skel);

Annotation

Implementation Notes