selftests/bpf: Test BPF_MAP_TYPE_PROG_ARRAY static initialization

Add testcase for BPF_MAP_TYPE_PROG_ARRAY static initialization.

Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211128141633.502339-3-hengqi.chen@gmail.com

diff --git a/tools/testing/selftests/bpf/prog_tests/prog_array_init.c b/tools/testing/selftests/bpf/prog_tests/prog_array_init.c
new file mode 100644 (file)
index 0000000..fc46576
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/prog_array_init.c
@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (c) 2021 Hengqi Chen */
+
+#include <test_progs.h>
+#include "test_prog_array_init.skel.h"
+
+void test_prog_array_init(void)
+{
+       struct test_prog_array_init *skel;
+       int err;
+
+       skel = test_prog_array_init__open();
+       if (!ASSERT_OK_PTR(skel, "could not open BPF object"))
+               return;
+
+       skel->rodata->my_pid = getpid();
+
+       err = test_prog_array_init__load(skel);
+       if (!ASSERT_OK(err, "could not load BPF object"))
+               goto cleanup;
+
+       skel->links.entry = bpf_program__attach_raw_tracepoint(skel->progs.entry, "sys_enter");
+       if (!ASSERT_OK_PTR(skel->links.entry, "could not attach BPF program"))
+               goto cleanup;
+
+       usleep(1);
+
+       ASSERT_EQ(skel->bss->value, 42, "unexpected value");
+
+cleanup:
+       test_prog_array_init__destroy(skel);
+}

diff --git a/tools/testing/selftests/bpf/progs/test_prog_array_init.c b/tools/testing/selftests/bpf/progs/test_prog_array_init.c
new file mode 100644 (file)
index 0000000..2cd1383
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_prog_array_init.c
@@ -0,0 +1,39 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (c) 2021 Hengqi Chen */
+
+#include "vmlinux.h"
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+
+const volatile pid_t my_pid = 0;
+int value = 0;
+
+SEC("raw_tp/sys_enter")
+int tailcall_1(void *ctx)
+{
+       value = 42;
+       return 0;
+}
+
+struct {
+       __uint(type, BPF_MAP_TYPE_PROG_ARRAY);
+       __uint(max_entries, 2);
+       __uint(key_size, sizeof(__u32));
+       __array(values, int (void *));
+} prog_array_init SEC(".maps") = {
+       .values = {
+               [1] = (void *)&tailcall_1,
+       },
+};
+
+SEC("raw_tp/sys_enter")
+int entry(void *ctx)
+{
+       pid_t pid = bpf_get_current_pid_tgid() >> 32;
+
+       if (pid != my_pid)
+               return 0;
+
+       bpf_tail_call(ctx, &prog_array_init, 1);
+       return 0;
+}