[PATCHv2,bpf-next,6/9] selftests/bpf: Add uprobe session test

Commit Message

Jiri Olsa July 1, 2024, 4:41 p.m. UTC

Adding uprobe session test and testing that the entry program
return value controls execution of the return probe program.

Signed-off-by: Jiri Olsa <[e-mail]>
---
 .../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

Comments

Andrii Nakryiko July 2, 2024, 9:57 p.m. UTC | #1

On Mon, Jul 1, 2024 at 9:43 AM Jiri Olsa <[e-mail]> 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 <[e-mail]>
> ---
>  .../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 <[e-mail]>

> 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
>

Patch

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());
+}