Subject: [PATCH bpf-next 24/29] selftests/bpf: Add fentry multi func test

From: Jiri Olsa <[email-masked]>
Date: Thu, 18 Nov 2021 12:24:50 +0100

Adding selftest for fentry multi func test that attaches
to bpf_fentry_test* functions and checks argument values
based on the processed function.

We need to cast to real arguments types in multi_arg_check,
because the checked value can be shorter than u64.

Signed-off-by: Jiri Olsa <[email-masked]>
---
 tools/testing/selftests/bpf/Makefile          |  4 +-
 .../bpf/prog_tests/multi_fentry_test.c        | 30 +++++++++
 .../testing/selftests/bpf/progs/multi_check.c | 63 +++++++++++++++++++
 .../selftests/bpf/progs/multi_fentry.c        | 17 +++++
 4 files changed, 113 insertions(+), 1 deletion(-)
 create mode 100644 tools/testing/selftests/bpf/prog_tests/multi_fentry_test.c
 create mode 100644 tools/testing/selftests/bpf/progs/multi_check.c
 create mode 100644 tools/testing/selftests/bpf/progs/multi_fentry.c

diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index 35684d61aaeb..fa29ddd47cbe 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -322,7 +322,8 @@ endef
 SKEL_BLACKLIST := btf__% test_pinning_invalid.c test_sk_assign.c
 
 LINKED_SKELS := test_static_linked.skel.h linked_funcs.skel.h		\
-		linked_vars.skel.h linked_maps.skel.h
+		linked_vars.skel.h linked_maps.skel.h			\
+		multi_fentry_test.skel.h
 
 LSKELS := kfunc_call_test.c fentry_test.c fexit_test.c fexit_sleep.c \
 	test_ringbuf.c atomics.c trace_printk.c trace_vprintk.c
@@ -334,6 +335,7 @@ test_static_linked.skel.h-deps := test_static_linked1.o test_static_linked2.o
 linked_funcs.skel.h-deps := linked_funcs1.o linked_funcs2.o
 linked_vars.skel.h-deps := linked_vars1.o linked_vars2.o
 linked_maps.skel.h-deps := linked_maps1.o linked_maps2.o
+multi_fentry_test.skel.h-deps := multi_fentry.o multi_check.o
 
 LINKED_BPF_SRCS := $(patsubst %.o,%.c,$(foreach skel,$(LINKED_SKELS),$($(skel)-deps)))
 
diff --git a/tools/testing/selftests/bpf/prog_tests/multi_fentry_test.c b/tools/testing/selftests/bpf/prog_tests/multi_fentry_test.c
new file mode 100644
index 000000000000..8dc08c3e715f
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/multi_fentry_test.c
@@ -0,0 +1,30 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <test_progs.h>
+#include "multi_fentry_test.skel.h"
+#include "trace_helpers.h"
+
+void test_multi_fentry_test(void)
+{
+	struct multi_fentry_test *skel = NULL;
+	__u32 duration = 0, retval;
+	int err, prog_fd;
+
+	skel = multi_fentry_test__open_and_load();
+	if (!ASSERT_OK_PTR(skel, "fentry_multi_skel_load"))
+		goto cleanup;
+
+	err = multi_fentry_test__attach(skel);
+	if (!ASSERT_OK(err, "fentry_attach"))
+		goto cleanup;
+
+	prog_fd = bpf_program__fd(skel->progs.test);
+	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->test_result, 8, "test_result");
+
+cleanup:
+	multi_fentry_test__destroy(skel);
+}
diff --git a/tools/testing/selftests/bpf/progs/multi_check.c b/tools/testing/selftests/bpf/progs/multi_check.c
new file mode 100644
index 000000000000..82acc9ee7715
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/multi_check.c
@@ -0,0 +1,63 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+
+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;
+
+void multi_arg_check(__u64 *ctx, __u64 *test_result)
+{
+	void *ip = (void *) bpf_get_func_ip(ctx);
+
+	if (ip == &bpf_fentry_test1) {
+		int a = (int) ctx[0];
+
+		*test_result += a == 1;
+	} else if (ip == &bpf_fentry_test2) {
+		int a = (int) bpf_arg(ctx, 0);
+		__u64 b = bpf_arg(ctx, 1);
+
+		*test_result += a == 2 && b == 3;
+	} else if (ip == &bpf_fentry_test3) {
+		char a = (int) bpf_arg(ctx, 0);
+		int b = (int) bpf_arg(ctx, 1);
+		__u64 c = bpf_arg(ctx, 2);
+
+		*test_result += a == 4 && b == 5 && c == 6;
+	} else if (ip == &bpf_fentry_test4) {
+		void *a = (void *) bpf_arg(ctx, 0);
+		char b = (char) bpf_arg(ctx, 1);
+		int c = (int) bpf_arg(ctx, 2);
+		__u64 d = bpf_arg(ctx, 3);
+
+		*test_result += a == (void *) 7 && b == 8 && c == 9 && d == 10;
+	} else if (ip == &bpf_fentry_test5) {
+		__u64 a = bpf_arg(ctx, 0);
+		void *b = (void *) bpf_arg(ctx, 1);
+		short c = (short) bpf_arg(ctx, 2);
+		int d = (int) bpf_arg(ctx, 3);
+		__u64 e = bpf_arg(ctx, 4);
+
+		*test_result += a == 11 && b == (void *) 12 && c == 13 && d == 14 && e == 15;
+	} else if (ip == &bpf_fentry_test6) {
+		__u64 a = bpf_arg(ctx, 0);
+		void *b = (void *) bpf_arg(ctx, 1);
+		short c = (short) bpf_arg(ctx, 2);
+		int d = (int) bpf_arg(ctx, 3);
+		void *e = (void *) bpf_arg(ctx, 4);
+		__u64 f = bpf_arg(ctx, 5);
+
+		*test_result += a == 16 && b == (void *) 17 && c == 18 && d == 19 && e == (void *) 20 && f == 21;
+	} else if (ip == &bpf_fentry_test7) {
+		*test_result += 1;
+	} else if (ip == &bpf_fentry_test8) {
+		*test_result += 1;
+	}
+}
diff --git a/tools/testing/selftests/bpf/progs/multi_fentry.c b/tools/testing/selftests/bpf/progs/multi_fentry.c
new file mode 100644
index 000000000000..b78d36772aa6
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/multi_fentry.c
@@ -0,0 +1,17 @@
+// 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";
+
+__u64 test_result = 0;
+
+__hidden extern void multi_arg_check(__u64 *ctx, __u64 *test_result);
+
+SEC("fentry.multi/bpf_fentry_test*")
+int BPF_PROG(test, __u64 a, __u64 b, __u64 c, __u64 d, __u64 e, __u64 f)
+{
+	multi_arg_check(ctx, &test_result);
+	return 0;
+}
-- 
2.31.1