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

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

File Facts

System
Linux kernel
Corpus path
tools/testing/selftests/bpf/prog_tests/ringbuf_multi.c
Extension
.c
Size
4460 bytes
Lines
148
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 sample {
	int pid;
	int seq;
	long value;
	char comm[16];
};

static int process_sample(void *ctx, void *data, size_t len)
{
	int ring = (unsigned long)ctx;
	struct sample *s = data;

	switch (s->seq) {
	case 0:
		CHECK(ring != 1, "sample1_ring", "exp %d, got %d\n", 1, ring);
		CHECK(s->value != 333, "sample1_value", "exp %ld, got %ld\n",
		      333L, s->value);
		break;
	case 1:
		CHECK(ring != 2, "sample2_ring", "exp %d, got %d\n", 2, ring);
		CHECK(s->value != 777, "sample2_value", "exp %ld, got %ld\n",
		      777L, s->value);
		break;
	default:
		CHECK(true, "extra_sample", "unexpected sample seq %d, val %ld\n",
		      s->seq, s->value);
		return -1;
	}

	return 0;
}

void test_ringbuf_multi(void)
{
	struct test_ringbuf_multi *skel;
	struct ring_buffer *ringbuf = NULL;
	struct ring *ring_old;
	struct ring *ring;
	int err;
	int page_size = getpagesize();
	int proto_fd = -1;

	skel = test_ringbuf_multi__open();
	if (CHECK(!skel, "skel_open", "skeleton open failed\n"))
		return;

	/* validate ringbuf size adjustment logic */
	ASSERT_EQ(bpf_map__max_entries(skel->maps.ringbuf1), page_size, "rb1_size_before");
	ASSERT_OK(bpf_map__set_max_entries(skel->maps.ringbuf1, page_size + 1), "rb1_resize");
	ASSERT_EQ(bpf_map__max_entries(skel->maps.ringbuf1), 2 * page_size, "rb1_size_after");
	ASSERT_OK(bpf_map__set_max_entries(skel->maps.ringbuf1, page_size), "rb1_reset");
	ASSERT_EQ(bpf_map__max_entries(skel->maps.ringbuf1), page_size, "rb1_size_final");

	proto_fd = bpf_map_create(BPF_MAP_TYPE_RINGBUF, NULL, 0, 0, page_size, NULL);
	if (CHECK(proto_fd < 0, "bpf_map_create", "bpf_map_create failed\n"))
		goto cleanup;

	err = bpf_map__set_inner_map_fd(skel->maps.ringbuf_hash, proto_fd);
	if (CHECK(err != 0, "bpf_map__set_inner_map_fd", "bpf_map__set_inner_map_fd failed\n"))
		goto cleanup;

	err = test_ringbuf_multi__load(skel);
	if (CHECK(err != 0, "skel_load", "skeleton load failed\n"))
		goto cleanup;

	close(proto_fd);
	proto_fd = -1;

	/* make sure we can't resize ringbuf after object load */
	if (!ASSERT_ERR(bpf_map__set_max_entries(skel->maps.ringbuf1, 3 * page_size), "rb1_resize_after_load"))
		goto cleanup;

	/* only trigger BPF program for current process */
	skel->bss->pid = getpid();

	ringbuf = ring_buffer__new(bpf_map__fd(skel->maps.ringbuf1),
				   process_sample, (void *)(long)1, NULL);
	if (CHECK(!ringbuf, "ringbuf_create", "failed to create ringbuf\n"))
		goto cleanup;

	/* verify ring_buffer__ring returns expected results */
	ring = ring_buffer__ring(ringbuf, 0);
	if (!ASSERT_OK_PTR(ring, "ring_buffer__ring_idx_0"))
		goto cleanup;
	ring_old = ring;
	ring = ring_buffer__ring(ringbuf, 1);
	ASSERT_ERR_PTR(ring, "ring_buffer__ring_idx_1");

	err = ring_buffer__add(ringbuf, bpf_map__fd(skel->maps.ringbuf2),
			      process_sample, (void *)(long)2);

Annotation

Implementation Notes