[PATCH 7/8] selftest/bpf: Add kprobe multi attach test

[Jiri Olsa <jolsa@redhat.com>]

Adding kprobe multi attach test that uses new interface
to attach multiple probes within single perf event.

The test is attaching to bpf_fentry_test* functions and
single trampoline program to use bpf_prog_test_run to
trigger bpf_fentry_test* functions.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
 .../bpf/prog_tests/multi_kprobe_test.c        | 83 +++++++++++++++++++
 .../selftests/bpf/progs/multi_kprobe.c        | 58 +++++++++++++
 2 files changed, 141 insertions(+)
 create mode 100644 tools/testing/selftests/bpf/prog_tests/multi_kprobe_test.c
 create mode 100644 tools/testing/selftests/bpf/progs/multi_kprobe.c

diff --git a/tools/testing/selftests/bpf/prog_tests/multi_kprobe_test.c b/tools/testing/selftests/bpf/prog_tests/multi_kprobe_test.c
new file mode 100644
index 000000000000..4aae472f9c16
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/multi_kprobe_test.c
@@ -0,0 +1,83 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <test_progs.h>
+#include "multi_kprobe.skel.h"
+#include "trace_helpers.h"
+
+static void test_funcs_api(void)
+{
+	struct multi_kprobe *skel = NULL;
+	__u32 duration = 0, retval;
+	int err, prog_fd;
+
+	skel = multi_kprobe__open_and_load();
+	if (!ASSERT_OK_PTR(skel, "fentry_multi_skel_load"))
+		goto cleanup;
+
+	err = multi_kprobe__attach(skel);
+	if (!ASSERT_OK(err, "fentry_attach"))
+		goto cleanup;
+
+	prog_fd = bpf_program__fd(skel->progs.test1);
+	err = bpf_prog_test_run(prog_fd, 1, NULL, 0,
+				NULL, NULL, &retval, &duration);
+	ASSERT_OK(err, "test_run");
+	ASSERT_EQ(retval, 0, "test_run");
+
+	ASSERT_EQ(skel->bss->test2_result, 8, "test2_result");
+	ASSERT_EQ(skel->bss->test3_result, 8, "test3_result");
+
+cleanup:
+	multi_kprobe__destroy(skel);
+}
+
+static void test_addrs_api(void)
+{
+	struct bpf_link *link1 = NULL, *link2 = NULL;
+	DECLARE_LIBBPF_OPTS(bpf_kprobe_opts, opts);
+	struct multi_kprobe *skel = NULL;
+	__u32 duration = 0, retval;
+	int err, prog_fd;
+	__u64 addrs[8];
+
+	skel = multi_kprobe__open_and_load();
+	if (!ASSERT_OK_PTR(skel, "fentry_multi_skel_load"))
+		goto cleanup;
+
+	kallsyms_find("bpf_fentry_test1", &addrs[0]);
+	kallsyms_find("bpf_fentry_test2", &addrs[1]);
+	kallsyms_find("bpf_fentry_test3", &addrs[2]);
+	kallsyms_find("bpf_fentry_test4", &addrs[3]);
+	kallsyms_find("bpf_fentry_test5", &addrs[4]);
+	kallsyms_find("bpf_fentry_test6", &addrs[5]);
+	kallsyms_find("bpf_fentry_test7", &addrs[6]);
+	kallsyms_find("bpf_fentry_test8", &addrs[7]);
+
+	opts.multi.cnt = 8;
+	opts.multi.addrs = (__u64 *) &addrs;
+	link1 = bpf_program__attach_kprobe_opts(skel->progs.test2, NULL, &opts);
+	if (!ASSERT_OK_PTR(link1, "link1"))
+		goto cleanup;
+
+	link2 = bpf_program__attach_kprobe_opts(skel->progs.test3, NULL, &opts);
+	if (!ASSERT_OK_PTR(link1, "link1"))
+		goto cleanup;
+
+	prog_fd = bpf_program__fd(skel->progs.test1);
+	err = bpf_prog_test_run(prog_fd, 1, NULL, 0,
+				NULL, NULL, &retval, &duration);
+	ASSERT_OK(err, "test_run");
+	ASSERT_EQ(retval, 0, "test_run");
+
+	ASSERT_EQ(skel->bss->test2_result, 8, "test2_result");
+	ASSERT_EQ(skel->bss->test3_result, 8, "test3_result");
+
+cleanup:
+	bpf_link__destroy(link1);
+	bpf_link__destroy(link2);
+	multi_kprobe__destroy(skel);
+}
+void test_multi_kprobe_test(void)
+{
+	test_funcs_api();
+	test_addrs_api();
+}
diff --git a/tools/testing/selftests/bpf/progs/multi_kprobe.c b/tools/testing/selftests/bpf/progs/multi_kprobe.c
new file mode 100644
index 000000000000..67fe4c2486fc
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/multi_kprobe.c
@@ -0,0 +1,58 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+
+char _license[] SEC("license") = "GPL";
+
+extern const void bpf_fentry_test1 __ksym;
+extern const void bpf_fentry_test2 __ksym;
+extern const void bpf_fentry_test3 __ksym;
+extern const void bpf_fentry_test4 __ksym;
+extern const void bpf_fentry_test5 __ksym;
+extern const void bpf_fentry_test6 __ksym;
+extern const void bpf_fentry_test7 __ksym;
+extern const void bpf_fentry_test8 __ksym;
+
+/* No tests, just to trigger bpf_fentry_test* through tracing test_run */
+SEC("fentry/bpf_modify_return_test")
+int BPF_PROG(test1)
+{
+	return 0;
+}
+
+__u64 test2_result = 0;
+
+SEC("kprobe.multi/bpf_fentry_test*")
+int test2(struct pt_regs *ctx)
+{
+	__u64 addr = bpf_get_func_ip(ctx);
+
+	test2_result += (const void *) addr == &bpf_fentry_test1 ||
+			(const void *) addr == &bpf_fentry_test2 ||
+			(const void *) addr == &bpf_fentry_test3 ||
+			(const void *) addr == &bpf_fentry_test4 ||
+			(const void *) addr == &bpf_fentry_test5 ||
+			(const void *) addr == &bpf_fentry_test6 ||
+			(const void *) addr == &bpf_fentry_test7 ||
+			(const void *) addr == &bpf_fentry_test8;
+	return 0;
+}
+
+__u64 test3_result = 0;
+
+SEC("kretprobe.multi/bpf_fentry_test*")
+int test3(struct pt_regs *ctx)
+{
+	__u64 addr = bpf_get_func_ip(ctx);
+
+	test3_result += (const void *) addr == &bpf_fentry_test1 ||
+			(const void *) addr == &bpf_fentry_test2 ||
+			(const void *) addr == &bpf_fentry_test3 ||
+			(const void *) addr == &bpf_fentry_test4 ||
+			(const void *) addr == &bpf_fentry_test5 ||
+			(const void *) addr == &bpf_fentry_test6 ||
+			(const void *) addr == &bpf_fentry_test7 ||
+			(const void *) addr == &bpf_fentry_test8;
+	return 0;
+}
-- 
2.33.1