[PATCHv2 bpf-next 3/3] selftests/bpf: Add bpf_get_func_ip test for uprobe inside function

Jiri Olsa
2023-08-03T09:52:56Z

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 <alan.maguire@oracle.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
.../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

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;
+}
--
2.41.0