On Mon, Jul 1, 2024 at 9:43 AM Jiri Olsa <jolsa@xxxxxxxxxx> wrote:
>
> Adding uprobe session test and testing that the entry program
> return value controls execution of the return probe program.
>
> Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
> ---
> .../bpf/prog_tests/uprobe_multi_test.c | 42 +++++++++++++++
> .../bpf/progs/uprobe_multi_session.c | 53 +++++++++++++++++++
> 2 files changed, 95 insertions(+)
> create mode 100644 tools/testing/selftests/bpf/progs/uprobe_multi_session.c
>
LGTM.
Acked-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
> diff --git a/tools/testing/selftests/bpf/prog_tests/uprobe_multi_test.c b/tools/testing/selftests/bpf/prog_tests/uprobe_multi_test.c
> index bf6ca8e3eb13..cd9581f46c73 100644
> --- a/tools/testing/selftests/bpf/prog_tests/uprobe_multi_test.c
> +++ b/tools/testing/selftests/bpf/prog_tests/uprobe_multi_test.c
> @@ -6,6 +6,7 @@
> #include "uprobe_multi.skel.h"
> #include "uprobe_multi_bench.skel.h"
> #include "uprobe_multi_usdt.skel.h"
> +#include "uprobe_multi_session.skel.h"
> #include "bpf/libbpf_internal.h"
> #include "testing_helpers.h"
> #include "../sdt.h"
> @@ -615,6 +616,45 @@ static void test_link_api(void)
> __test_link_api(child);
> }
>
> +static void test_session_skel_api(void)
> +{
> + struct uprobe_multi_session *skel = NULL;
> + LIBBPF_OPTS(bpf_kprobe_multi_opts, opts);
> + struct bpf_link *link = NULL;
> + int err;
> +
> + skel = uprobe_multi_session__open_and_load();
> + if (!ASSERT_OK_PTR(skel, "fentry_raw_skel_load"))
> + goto cleanup;
> +
> + skel->bss->pid = getpid();
> +
> + err = uprobe_multi_session__attach(skel);
> + if (!ASSERT_OK(err, " uprobe_multi_session__attach"))
> + goto cleanup;
> +
> + /* trigger all probes */
> + skel->bss->uprobe_multi_func_1_addr = (__u64) uprobe_multi_func_1;
> + skel->bss->uprobe_multi_func_2_addr = (__u64) uprobe_multi_func_2;
> + skel->bss->uprobe_multi_func_3_addr = (__u64) uprobe_multi_func_3;
> +
> + uprobe_multi_func_1();
> + uprobe_multi_func_2();
> + uprobe_multi_func_3();
> +
> + /*
> + * We expect 2 for uprobe_multi_func_2 because it runs both entry/return probe,
> + * uprobe_multi_func_[13] run just the entry probe.
> + */
> + ASSERT_EQ(skel->bss->uprobe_session_result[0], 1, "uprobe_multi_func_1_result");
> + ASSERT_EQ(skel->bss->uprobe_session_result[1], 2, "uprobe_multi_func_2_result");
> + ASSERT_EQ(skel->bss->uprobe_session_result[2], 1, "uprobe_multi_func_3_result");
> +
> +cleanup:
> + bpf_link__destroy(link);
> + uprobe_multi_session__destroy(skel);
> +}
> +
> static void test_bench_attach_uprobe(void)
> {
> long attach_start_ns = 0, attach_end_ns = 0;
> @@ -703,4 +743,6 @@ void test_uprobe_multi_test(void)
> test_bench_attach_usdt();
> if (test__start_subtest("attach_api_fails"))
> test_attach_api_fails();
> + if (test__start_subtest("session"))
> + test_session_skel_api();
> }
> diff --git a/tools/testing/selftests/bpf/progs/uprobe_multi_session.c b/tools/testing/selftests/bpf/progs/uprobe_multi_session.c
> new file mode 100644
> index 000000000000..72c00ae68372
> --- /dev/null
> +++ b/tools/testing/selftests/bpf/progs/uprobe_multi_session.c
> @@ -0,0 +1,53 @@
> +// SPDX-License-Identifier: GPL-2.0
> +#include <linux/bpf.h>
> +#include <bpf/bpf_helpers.h>
> +#include <bpf/bpf_tracing.h>
> +#include <stdbool.h>
> +#include "bpf_kfuncs.h"
> +#include "bpf_misc.h"
> +
> +char _license[] SEC("license") = "GPL";
> +
> +__u64 uprobe_multi_func_1_addr = 0;
> +__u64 uprobe_multi_func_2_addr = 0;
> +__u64 uprobe_multi_func_3_addr = 0;
> +
> +__u64 uprobe_session_result[3];
> +
> +int pid = 0;
> +
> +static int uprobe_multi_check(void *ctx, bool is_return)
> +{
> + const __u64 funcs[] = {
> + uprobe_multi_func_1_addr,
> + uprobe_multi_func_2_addr,
> + uprobe_multi_func_3_addr,
> + };
> + unsigned int i;
> + __u64 addr;
> +
> + if (bpf_get_current_pid_tgid() >> 32 != pid)
> + return 1;
> +
> + addr = bpf_get_func_ip(ctx);
> +
> + for (i = 0; i < ARRAY_SIZE(funcs); i++) {
> + if (funcs[i] == addr) {
> + uprobe_session_result[i]++;
> + break;
> + }
> + }
> +
> + /* only uprobe_multi_func_2 executes return probe */
> + if ((addr == uprobe_multi_func_1_addr) ||
> + (addr == uprobe_multi_func_3_addr))
> + return 1;
> +
> + return 0;
> +}
> +
> +SEC("uprobe.session//proc/self/exe:uprobe_multi_func_*")
> +int uprobe(struct pt_regs *ctx)
> +{
> + return uprobe_multi_check(ctx, bpf_session_is_return());
> +}
> --
> 2.45.2
>
