Change the values of fields, including scalar types and function pointers,
and check if the struct_ops map works as expected.
The test changes the field "test_2" of "testmod_1" from the pointer to
test_2() to pointer to test_3() and the field "data" to 13. The function
test_2() and test_3() both compute a new value for "test_2_result", but in
different way. By checking the value of "test_2_result", it ensures the
struct_ops map works as expected with changes through shadow types.
Signed-off-by: Kui-Feng Lee <thinker.li@xxxxxxxxx>
---
.../selftests/bpf/bpf_testmod/bpf_testmod.c | 11 ++++++++++-
.../selftests/bpf/bpf_testmod/bpf_testmod.h | 8 ++++++++
.../bpf/prog_tests/test_struct_ops_module.c | 19 +++++++++++++++----
.../selftests/bpf/progs/struct_ops_module.c | 8 ++++++++
4 files changed, 41 insertions(+), 5 deletions(-)
diff --git a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
index 66787e99ba1b..098ddd067224 100644
--- a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
+++ b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
@@ -539,6 +539,15 @@ static int bpf_testmod_ops_init_member(const struct btf_type *t,
const struct btf_member *member,
void *kdata, const void *udata)
{
+ if (member->offset == offsetof(struct bpf_testmod_ops, data) * 8) {
+ /* For data fields, this function has to copy it and return
+ * 1 to indicate that the data has been handled by the
+ * struct_ops type, or the verifier will reject the map if
+ * the value of the data field is not zero.
+ */
+ ((struct bpf_testmod_ops *)kdata)->data = ((struct bpf_testmod_ops *)udata)->data;
+ return 1;
+ }
return 0;
}
@@ -559,7 +568,7 @@ static int bpf_dummy_reg(void *kdata)
* initialized, so we need to check for NULL.
*/
if (ops->test_2)
- ops->test_2(4, 3);
+ ops->test_2(4, ops->data);
return 0;
}
diff --git a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.h b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.h
index c3b0cf788f9f..971458acfac3 100644
--- a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.h
+++ b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.h
@@ -35,6 +35,14 @@ struct bpf_testmod_ops {
void (*test_2)(int a, int b);
/* Used to test nullable arguments. */
int (*test_maybe_null)(int dummy, struct task_struct *task);
+
+ /* The following fields are used to test shadow copies. */
+ char onebyte;
+ struct {
+ int a;
+ int b;
+ } unsupported;
+ int data;
};
#endif /* _BPF_TESTMOD_H */
diff --git a/tools/testing/selftests/bpf/prog_tests/test_struct_ops_module.c b/tools/testing/selftests/bpf/prog_tests/test_struct_ops_module.c
index 8d833f0c7580..7d6facf46ebb 100644
--- a/tools/testing/selftests/bpf/prog_tests/test_struct_ops_module.c
+++ b/tools/testing/selftests/bpf/prog_tests/test_struct_ops_module.c
@@ -32,17 +32,23 @@ static void check_map_info(struct bpf_map_info *info)
static void test_struct_ops_load(void)
{
- DECLARE_LIBBPF_OPTS(bpf_object_open_opts, opts);
struct struct_ops_module *skel;
struct bpf_map_info info = {};
struct bpf_link *link;
int err;
u32 len;
- skel = struct_ops_module__open_opts(&opts);
+ skel = struct_ops_module__open();
if (!ASSERT_OK_PTR(skel, "struct_ops_module_open"))
return;
+ skel->struct_ops.testmod_1->data = 13;
+ skel->struct_ops.testmod_1->test_2 = skel->progs.test_3;
+ /* Since test_2() is not being used, it should be disabled from
+ * auto-loading, or it will fail to load.
+ */
+ bpf_program__set_autoload(skel->progs.test_2, false);
+
err = struct_ops_module__load(skel);
if (!ASSERT_OK(err, "struct_ops_module_load"))
goto cleanup;
@@ -56,8 +62,13 @@ static void test_struct_ops_load(void)
link = bpf_map__attach_struct_ops(skel->maps.testmod_1);
ASSERT_OK_PTR(link, "attach_test_mod_1");
- /* test_2() will be called from bpf_dummy_reg() in bpf_testmod.c */
- ASSERT_EQ(skel->bss->test_2_result, 7, "test_2_result");
+ /* test_3() will be called from bpf_dummy_reg() in bpf_testmod.c
+ *
+ * In bpf_testmod.c it will pass 4 and 13 (the value of data) to
+ * .test_2. So, the value of test_2_result should be 20 (4 + 13 +
+ * 3).
+ */
+ ASSERT_EQ(skel->bss->test_2_result, 20, "check_shadow_variables");
bpf_link__destroy(link);
diff --git a/tools/testing/selftests/bpf/progs/struct_ops_module.c b/tools/testing/selftests/bpf/progs/struct_ops_module.c
index b78746b3cef3..25952fa09348 100644
--- a/tools/testing/selftests/bpf/progs/struct_ops_module.c
+++ b/tools/testing/selftests/bpf/progs/struct_ops_module.c
@@ -21,9 +21,17 @@ void BPF_PROG(test_2, int a, int b)
test_2_result = a + b;
}
+SEC("struct_ops/test_3")
+int BPF_PROG(test_3, int a, int b)
+{
+ test_2_result = a + b + 3;
+ return a + b + 3;
+}
+
SEC(".struct_ops.link")
struct bpf_testmod_ops testmod_1 = {
.test_1 = (void *)test_1,
.test_2 = (void *)test_2,
+ .data = 0x1,
};
--
2.34.1
