[PATCHv3,bpf-next,3/3] selftests/bpf: Add bpf_get_func_ip test for uprobe inside function

Commit Message

Jiri Olsa Aug. 7, 2023, 8:59 a.m. UTC

Adding get_func_ip test for uprobe inside function that validates
the get_func_ip helper returns correct probe address value.

Tested-by: Alan Maguire <[e-mail]>
Signed-off-by: Jiri Olsa <[e-mail]>
---
 .../bpf/prog_tests/get_func_ip_test.c         | 46 +++++++++++++++++--
 .../bpf/progs/get_func_ip_uprobe_test.c       | 18 ++++++++
 2 files changed, 60 insertions(+), 4 deletions(-)
 create mode 100644 tools/testing/selftests/bpf/progs/get_func_ip_uprobe_test.c

Comments

Yonghong Song Aug. 7, 2023, 4:02 p.m. UTC | #1

On 8/7/23 1:59 AM, Jiri Olsa wrote:
> Adding get_func_ip test for uprobe inside function that validates
> the get_func_ip helper returns correct probe address value.
> 
> Tested-by: Alan Maguire <[e-mail]>
> Signed-off-by: Jiri Olsa <[e-mail]>

Acked-by: Yonghong Song <[e-mail]>

Patch

diff --git a/tools/testing/selftests/bpf/prog_tests/get_func_ip_test.c b/tools/testing/selftests/bpf/prog_tests/get_func_ip_test.c
index 114cdbc04caf..c40242dfa8fb 100644
--- a/tools/testing/selftests/bpf/prog_tests/get_func_ip_test.c
+++ b/tools/testing/selftests/bpf/prog_tests/get_func_ip_test.c
@@ -51,11 +51,17 @@  static void test_function_entry(void)
 	get_func_ip_test__destroy(skel);
 }
 
-/* test6 is x86_64 specific because of the instruction
- * offset, disabling it for all other archs
- */
 #ifdef __x86_64__
-static void test_function_body(void)
+extern void uprobe_trigger_body(void);
+asm(
+".globl uprobe_trigger_body\n"
+".type uprobe_trigger_body, @function\n"
+"uprobe_trigger_body:\n"
+"	nop\n"
+"	ret\n"
+);
+
+static void test_function_body_kprobe(void)
 {
 	struct get_func_ip_test *skel = NULL;
 	LIBBPF_OPTS(bpf_test_run_opts, topts);
@@ -67,6 +73,9 @@  static void test_function_body(void)
 	if (!ASSERT_OK_PTR(skel, "get_func_ip_test__open"))
 		return;
 
+	/* test6 is x86_64 specific and is disabled by default,
+	 * enable it for body test.
+	 */
 	bpf_program__set_autoload(skel->progs.test6, true);
 
 	err = get_func_ip_test__load(skel);
@@ -90,6 +99,35 @@  static void test_function_body(void)
 	bpf_link__destroy(link6);
 	get_func_ip_test__destroy(skel);
 }
+
+static void test_function_body_uprobe(void)
+{
+	struct get_func_ip_uprobe_test *skel = NULL;
+	int err;
+
+	skel = get_func_ip_uprobe_test__open_and_load();
+	if (!ASSERT_OK_PTR(skel, "get_func_ip_uprobe_test__open_and_load"))
+		return;
+
+	err = get_func_ip_uprobe_test__attach(skel);
+	if (!ASSERT_OK(err, "get_func_ip_test__attach"))
+		goto cleanup;
+
+	skel->bss->uprobe_trigger_body = (unsigned long) uprobe_trigger_body;
+
+	uprobe_trigger_body();
+
+	ASSERT_EQ(skel->bss->test1_result, 1, "test1_result");
+
+cleanup:
+	get_func_ip_uprobe_test__destroy(skel);
+}
+
+static void test_function_body(void)
+{
+	test_function_body_kprobe();
+	test_function_body_uprobe();
+}
 #else
 #define test_function_body()
 #endif
diff --git a/tools/testing/selftests/bpf/progs/get_func_ip_uprobe_test.c b/tools/testing/selftests/bpf/progs/get_func_ip_uprobe_test.c
new file mode 100644
index 000000000000..052f8a4345a8
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/get_func_ip_uprobe_test.c
@@ -0,0 +1,18 @@ 
+// SPDX-License-Identifier: GPL-2.0
+#include "vmlinux.h"
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+
+char _license[] SEC("license") = "GPL";
+
+unsigned long uprobe_trigger_body;
+
+__u64 test1_result = 0;
+SEC("uprobe//proc/self/exe:uprobe_trigger_body+1")
+int BPF_UPROBE(test1)
+{
+	__u64 addr = bpf_get_func_ip(ctx);
+
+	test1_result = (const void *) addr == (const void *) uprobe_trigger_body + 1;
+	return 0;
+}