[PATCH bpf-next v3 2/2] selftests/bpf: add test case for bpf_map_lookup_percpu_elem

[Feng zhou <zhoufeng.zf@xxxxxxxxxxxxx>]

From: Feng Zhou <zhoufeng.zf@xxxxxxxxxxxxx>

test_progs:
Tests new ebpf helpers bpf_map_lookup_percpu_elem.

Signed-off-by: Feng Zhou <zhoufeng.zf@xxxxxxxxxxxxx>
---
 .../bpf/prog_tests/map_lookup_percpu_elem.c   | 59 +++++++++++++++
 .../bpf/progs/test_map_lookup_percpu_elem.c   | 71 +++++++++++++++++++
 2 files changed, 130 insertions(+)
 create mode 100644 tools/testing/selftests/bpf/prog_tests/map_lookup_percpu_elem.c
 create mode 100644 tools/testing/selftests/bpf/progs/test_map_lookup_percpu_elem.c

diff --git a/tools/testing/selftests/bpf/prog_tests/map_lookup_percpu_elem.c b/tools/testing/selftests/bpf/prog_tests/map_lookup_percpu_elem.c
new file mode 100644
index 000000000000..89ca170f1c25
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/map_lookup_percpu_elem.c
@@ -0,0 +1,59 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (c) 2022 Bytedance */
+
+#include <test_progs.h>
+
+#include "test_map_lookup_percpu_elem.skel.h"
+
+void test_map_lookup_percpu_elem(void)
+{
+	struct test_map_lookup_percpu_elem *skel;
+	__u64 key = 0, sum;
+	int ret, i;
+	int nr_cpus = libbpf_num_possible_cpus();
+	__u64 *buf;
+
+	buf = (__u64 *)malloc(nr_cpus*sizeof(__u64));
+	if (!ASSERT_OK_PTR(buf, "malloc"))
+		return;
+
+	for (i=0; i<nr_cpus; i++)
+		buf[i] = i;
+	sum = (nr_cpus-1)*nr_cpus/2;
+
+	skel = test_map_lookup_percpu_elem__open();
+	if (!ASSERT_OK_PTR(skel, "test_map_lookup_percpu_elem__open"))
+		goto exit;
+
+	skel->rodata->nr_cpus = nr_cpus;
+
+	ret = test_map_lookup_percpu_elem__load(skel);
+	if (!ASSERT_OK(ret, "test_map_lookup_percpu_elem__load"))
+		goto cleanup;
+
+	ret = test_map_lookup_percpu_elem__attach(skel);
+	if (!ASSERT_OK(ret, "test_map_lookup_percpu_elem__attach"))
+		goto cleanup;
+
+	ret = bpf_map_update_elem(bpf_map__fd(skel->maps.percpu_array_map), &key, buf, 0);
+	ASSERT_OK(ret, "percpu_array_map update");
+
+	ret = bpf_map_update_elem(bpf_map__fd(skel->maps.percpu_hash_map), &key, buf, 0);
+	ASSERT_OK(ret, "percpu_hash_map update");
+
+	ret = bpf_map_update_elem(bpf_map__fd(skel->maps.percpu_lru_hash_map), &key, buf, 0);
+	ASSERT_OK(ret, "percpu_lru_hash_map update");
+
+	syscall(__NR_getuid);
+
+	test_map_lookup_percpu_elem__detach(skel);
+
+	ASSERT_EQ(skel->bss->percpu_array_elem_sum, sum, "percpu_array lookup percpu elem");
+	ASSERT_EQ(skel->bss->percpu_hash_elem_sum, sum, "percpu_hash lookup percpu elem");
+	ASSERT_EQ(skel->bss->percpu_lru_hash_elem_sum, sum, "percpu_lru_hash lookup percpu elem");
+
+cleanup:
+	test_map_lookup_percpu_elem__destroy(skel);
+exit:
+	free(buf);
+}
diff --git a/tools/testing/selftests/bpf/progs/test_map_lookup_percpu_elem.c b/tools/testing/selftests/bpf/progs/test_map_lookup_percpu_elem.c
new file mode 100644
index 000000000000..75479180571f
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_map_lookup_percpu_elem.c
@@ -0,0 +1,71 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (c) 2022 Bytedance */
+
+#include "vmlinux.h"
+#include <bpf/bpf_helpers.h>
+
+__u64 percpu_array_elem_sum = 0;
+__u64 percpu_hash_elem_sum = 0;
+__u64 percpu_lru_hash_elem_sum = 0;
+const volatile int nr_cpus;
+
+struct {
+	__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
+	__uint(max_entries, 1);
+	__type(key, __u32);
+	__type(value, __u64);
+} percpu_array_map SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_PERCPU_HASH);
+	__uint(max_entries, 1);
+	__type(key, __u64);
+	__type(value, __u64);
+} percpu_hash_map SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_LRU_PERCPU_HASH);
+	__uint(max_entries, 1);
+	__type(key, __u64);
+	__type(value, __u64);
+} percpu_lru_hash_map SEC(".maps");
+
+struct read_percpu_elem_ctx {
+	void *map;
+	__u64 sum;
+};
+
+static int read_percpu_elem_callback(__u32 index, struct read_percpu_elem_ctx *ctx)
+{
+	__u64 key = 0;
+	__u64 *value;
+	value = bpf_map_lookup_percpu_elem(ctx->map, &key, index);
+	if (value)
+		ctx->sum += *value;
+	return 0;
+}
+
+SEC("tp/syscalls/sys_enter_getuid")
+int sysenter_getuid(const void *ctx)
+{
+	struct read_percpu_elem_ctx map_ctx;
+
+	map_ctx.map = &percpu_array_map;
+	map_ctx.sum = 0;
+	bpf_loop(nr_cpus, read_percpu_elem_callback, &map_ctx, 0);
+	percpu_array_elem_sum = map_ctx.sum;
+
+	map_ctx.map = &percpu_hash_map;
+	map_ctx.sum = 0;
+	bpf_loop(nr_cpus, read_percpu_elem_callback, &map_ctx, 0);
+	percpu_hash_elem_sum = map_ctx.sum;
+
+	map_ctx.map = &percpu_lru_hash_map;
+	map_ctx.sum = 0;
+	bpf_loop(nr_cpus, read_percpu_elem_callback, &map_ctx, 0);
+	percpu_lru_hash_elem_sum = map_ctx.sum;
+
+	return 0;
+}
+
+char _license[] SEC("license") = "GPL";
-- 
2.20.1