Re: [PATCH 16/19] selftests/bpf: Add fentry multi func test

[Yonghong Song <yhs@fb.com>]

On 6/5/21 4:10 AM, Jiri Olsa wrote:
> Adding selftest for fentry multi func test that attaches
> to bpf_fentry_test* functions and checks argument values
> based on the processed function.
> 
> Signed-off-by: Jiri Olsa <jolsa@kernel.org>
> ---
>   tools/testing/selftests/bpf/multi_check.h     | 52 +++++++++++++++++++

Should we put this file under selftests/bpf/progs directory?
It is included only by bpf programs.

>   .../bpf/prog_tests/fentry_multi_test.c        | 43 +++++++++++++++
>   .../selftests/bpf/progs/fentry_multi_test.c   | 18 +++++++
>   3 files changed, 113 insertions(+)
>   create mode 100644 tools/testing/selftests/bpf/multi_check.h
>   create mode 100644 tools/testing/selftests/bpf/prog_tests/fentry_multi_test.c
>   create mode 100644 tools/testing/selftests/bpf/progs/fentry_multi_test.c
> 
> diff --git a/tools/testing/selftests/bpf/multi_check.h b/tools/testing/selftests/bpf/multi_check.h
> new file mode 100644
> index 000000000000..36c2a93f9be3
> --- /dev/null
> +++ b/tools/testing/selftests/bpf/multi_check.h
> @@ -0,0 +1,52 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +
> +#ifndef __MULTI_CHECK_H
> +#define __MULTI_CHECK_H
> +
> +extern unsigned long long bpf_fentry_test[8];
> +
> +static __attribute__((unused)) inline
> +void multi_arg_check(unsigned long ip, __u64 a, __u64 b, __u64 c, __u64 d, __u64 e, __u64 f, __u64 *test_result)
> +{
> +	if (ip == bpf_fentry_test[0]) {
> +		*test_result += (int) a == 1;
> +	} else if (ip == bpf_fentry_test[1]) {
> +		*test_result += (int) a == 2 && (__u64) b == 3;
> +	} else if (ip == bpf_fentry_test[2]) {
> +		*test_result += (char) a == 4 && (int) b == 5 && (__u64) c == 6;
> +	} else if (ip == bpf_fentry_test[3]) {
> +		*test_result += (void *) a == (void *) 7 && (char) b == 8 && (int) c == 9 && (__u64) d == 10;
> +	} else if (ip == bpf_fentry_test[4]) {
> +		*test_result += (__u64) a == 11 && (void *) b == (void *) 12 && (short) c == 13 && (int) d == 14 && (__u64) e == 15;
> +	} else if (ip == bpf_fentry_test[5]) {
> +		*test_result += (__u64) a == 16 && (void *) b == (void *) 17 && (short) c == 18 && (int) d == 19 && (void *) e == (void *) 20 && (__u64) f == 21;
> +	} else if (ip == bpf_fentry_test[6]) {
> +		*test_result += 1;
> +	} else if (ip == bpf_fentry_test[7]) {
> +		*test_result += 1;
> +	}
> +}
> +
> +static __attribute__((unused)) inline
> +void multi_ret_check(unsigned long ip, int ret, __u64 *test_result)
> +{
> +	if (ip == bpf_fentry_test[0]) {
> +		*test_result += ret == 2;
> +	} else if (ip == bpf_fentry_test[1]) {
> +		*test_result += ret == 5;
> +	} else if (ip == bpf_fentry_test[2]) {
> +		*test_result += ret == 15;
> +	} else if (ip == bpf_fentry_test[3]) {
> +		*test_result += ret == 34;
> +	} else if (ip == bpf_fentry_test[4]) {
> +		*test_result += ret == 65;
> +	} else if (ip == bpf_fentry_test[5]) {
> +		*test_result += ret == 111;
> +	} else if (ip == bpf_fentry_test[6]) {
> +		*test_result += ret == 0;
> +	} else if (ip == bpf_fentry_test[7]) {
> +		*test_result += ret == 0;
> +	}
> +}
> +
> +#endif /* __MULTI_CHECK_H */
> diff --git a/tools/testing/selftests/bpf/prog_tests/fentry_multi_test.c b/tools/testing/selftests/bpf/prog_tests/fentry_multi_test.c
> new file mode 100644
> index 000000000000..e4a8089533d6
> --- /dev/null
> +++ b/tools/testing/selftests/bpf/prog_tests/fentry_multi_test.c
> @@ -0,0 +1,43 @@
> +// SPDX-License-Identifier: GPL-2.0
> +#include <test_progs.h>
> +#include "fentry_multi_test.skel.h"
> +#include "trace_helpers.h"
> +
> +void test_fentry_multi_test(void)
> +{
> +	struct fentry_multi_test *skel = NULL;
> +	unsigned long long *bpf_fentry_test;
> +	__u32 duration = 0, retval;
> +	int err, prog_fd;
> +
> +	skel = fentry_multi_test__open_and_load();
> +	if (!ASSERT_OK_PTR(skel, "fentry_multi_skel_load"))
> +		goto cleanup;
> +
> +	bpf_fentry_test = &skel->bss->bpf_fentry_test[0];
> +	ASSERT_OK(kallsyms_find("bpf_fentry_test1", &bpf_fentry_test[0]), "kallsyms_find");
> +	ASSERT_OK(kallsyms_find("bpf_fentry_test2", &bpf_fentry_test[1]), "kallsyms_find");
> +	ASSERT_OK(kallsyms_find("bpf_fentry_test3", &bpf_fentry_test[2]), "kallsyms_find");
> +	ASSERT_OK(kallsyms_find("bpf_fentry_test4", &bpf_fentry_test[3]), "kallsyms_find");
> +	ASSERT_OK(kallsyms_find("bpf_fentry_test5", &bpf_fentry_test[4]), "kallsyms_find");
> +	ASSERT_OK(kallsyms_find("bpf_fentry_test6", &bpf_fentry_test[5]), "kallsyms_find");
> +	ASSERT_OK(kallsyms_find("bpf_fentry_test7", &bpf_fentry_test[6]), "kallsyms_find");
> +	ASSERT_OK(kallsyms_find("bpf_fentry_test8", &bpf_fentry_test[7]), "kallsyms_find");
> +
> +	err = fentry_multi_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");
> +
> +	fentry_multi_test__detach(skel);
> +
> +cleanup:
> +	fentry_multi_test__destroy(skel);
> +}
> diff --git a/tools/testing/selftests/bpf/progs/fentry_multi_test.c b/tools/testing/selftests/bpf/progs/fentry_multi_test.c
> new file mode 100644
> index 000000000000..a443fc958e5a
> --- /dev/null
> +++ b/tools/testing/selftests/bpf/progs/fentry_multi_test.c
> @@ -0,0 +1,18 @@
> +// SPDX-License-Identifier: GPL-2.0
> +#include <linux/bpf.h>
> +#include <bpf/bpf_helpers.h>
> +#include <bpf/bpf_tracing.h>
> +#include "multi_check.h"
> +
> +char _license[] SEC("license") = "GPL";
> +
> +unsigned long long bpf_fentry_test[8];
> +
> +__u64 test_result = 0;
> +
> +SEC("fentry.multi/bpf_fentry_test*")
> +int BPF_PROG(test, unsigned long ip, __u64 a, __u64 b, __u64 c, __u64 d, __u64 e, __u64 f)
> +{
> +	multi_arg_check(ip, a, b, c, d, e, f, &test_result);
> +	return 0;
> +}
>