selftests/bpf: Add tracing multi session test

Signed-off-by: Jiri Olsa <jolsa@kernel.org>

Author: olsajiri

tools/testing/selftests/bpf/Makefile

@@ -482,7 +482,8 @@ LINKED_SKELS := test_static_linked.skel.h linked_funcs.skel.h		\
 		linked_vars.skel.h linked_maps.skel.h 			\
 		test_subskeleton.skel.h test_subskeleton_lib.skel.h	\
 		test_usdt.skel.h tracing_multi.skel.h			\
-		tracing_multi_intersect.skel.h
+		tracing_multi_intersect.skel.h				\
+		tracing_multi_session.skel.h
 
 LSKELS := fexit_sleep.c trace_printk.c trace_vprintk.c map_ptr_kern.c 	\
 	core_kern.c core_kern_overflow.c test_ringbuf.c			\
@@ -510,6 +511,7 @@ xdp_hw_metadata.skel.h-deps := xdp_hw_metadata.bpf.o
 xdp_features.skel.h-deps := xdp_features.bpf.o
 tracing_multi.skel.h-deps := tracing_multi_attach.bpf.o tracing_multi_check.bpf.o
 tracing_multi_intersect.skel.h-deps := tracing_multi_intersect_attach.bpf.o tracing_multi_check.bpf.o
+tracing_multi_session.skel.h-deps := tracing_multi_session_attach.bpf.o tracing_multi_check.bpf.o
 
 LINKED_BPF_OBJS := $(foreach skel,$(LINKED_SKELS),$($(skel)-deps))
 LINKED_BPF_SRCS := $(patsubst %.bpf.o,%.c,$(LINKED_BPF_OBJS))

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

@@ -6,6 +6,7 @@
 #include "bpf/libbpf_internal.h"
 #include "tracing_multi.skel.h"
 #include "tracing_multi_intersect.skel.h"
+#include "tracing_multi_session.skel.h"
 #include "trace_helpers.h"
 
 static __u64 bpf_fentry_test_cookies[] = {
@@ -288,6 +289,32 @@ static void test_intersect(void)
 	tracing_multi_intersect__destroy(skel);
 }
 
+static void test_session(void)
+{
+	LIBBPF_OPTS(bpf_test_run_opts, topts);
+	struct tracing_multi_session *skel;
+	int err, prog_fd;
+
+	skel = tracing_multi_session__open_and_load();
+	if (!ASSERT_OK_PTR(skel, "tracing_multi_session__open_and_load"))
+		return;
+
+	err = tracing_multi_session__attach(skel);
+	if (!ASSERT_OK(err, "tracing_multi_session__attach"))
+		goto cleanup;
+
+	prog_fd = bpf_program__fd(skel->progs.test_session);
+	err = bpf_prog_test_run_opts(prog_fd, &topts);
+	ASSERT_OK(err, "test_run");
+
+	ASSERT_EQ(skel->bss->test_result_fentry, 10, "test_result_fentry");
+	/* extra count for test_result_fexit cookie */
+	ASSERT_EQ(skel->bss->test_result_fexit, 20, "test_result_fexit");
+
+cleanup:
+	tracing_multi_session__destroy(skel);
+}
+
 void test_tracing_multi_test(void)
 {
 #ifndef __x86_64__
@@ -305,4 +332,6 @@ void test_tracing_multi_test(void)
 		test_intersect();
 	if (test__start_subtest("cookies"))
 		test_link_api_ids(true);
+	if (test__start_subtest("session"))
+		test_session();
 }

tools/testing/selftests/bpf/progs/tracing_multi_session_attach.c

@@ -0,0 +1,27 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <vmlinux.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+
+char _license[] SEC("license") = "GPL";
+
+__hidden extern int tracing_multi_arg_check(__u64 *ctx, __u64 *test_result, bool is_return);
+
+__u64 test_result_fentry = 0;
+__u64 test_result_fexit = 0;
+
+SEC("fsession.multi/bpf_fentry_test*")
+int BPF_PROG(test_session)
+{
+	volatile __u64 *cookie = bpf_session_cookie(ctx);
+
+	if (bpf_session_is_return(ctx)) {
+		tracing_multi_arg_check(ctx, &test_result_fexit, true);
+		/* extra count for test_result_fexit cookie */
+		test_result_fexit += *cookie == 0xbeafbeafbeafbeaf;
+	} else {
+		tracing_multi_arg_check(ctx, &test_result_fentry, false);
+		*cookie = 0xbeafbeafbeafbeaf;
+	}
+	return 0;
+}