[PATCH HID v2 09/16] selftests/hid: add subprog call test

Benjamin Tissoires
2024-06-07T15:28:53Z

I got a weird verifier error with a subprog once, so let's have a test
for it.

Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>

---

no changes in v2
---
tools/testing/selftests/hid/hid_bpf.c | 41 +++++++++++++++++++++++++++++++++
tools/testing/selftests/hid/progs/hid.c | 24 +++++++++++++++++++
2 files changed, 65 insertions(+)

diff --git a/tools/testing/selftests/hid/hid_bpf.c b/tools/testing/selftests/hid/hid_bpf.c
index 967dfe6b58cb..45e173db35bd 100644
--- a/tools/testing/selftests/hid/hid_bpf.c
+++ b/tools/testing/selftests/hid/hid_bpf.c
@@ -638,6 +638,47 @@ TEST_F(hid_bpf, raw_event)
ASSERT_EQ(buf[2], 52);
}

+/*
+ * Attach hid_first_event to the given uhid device,
+ * retrieve and open the matching hidraw node,
+ * inject one event in the uhid device,
+ * check that the program sees it and can change the data
+ */
+TEST_F(hid_bpf, subprog_raw_event)
+{
+ const struct test_program progs[] = {
+ { .name = "hid_subprog_first_event" },
+ };
+ __u8 buf[10] = {0};
+ int err;
+
+ LOAD_PROGRAMS(progs);
+
+ /* inject one event */
+ buf[0] = 1;
+ buf[1] = 42;
+ uhid_send_event(_metadata, self->uhid_fd, buf, 6);
+
+ /* read the data from hidraw */
+ memset(buf, 0, sizeof(buf));
+ err = read(self->hidraw_fd, buf, sizeof(buf));
+ ASSERT_EQ(err, 6) TH_LOG("read_hidraw");
+ ASSERT_EQ(buf[0], 1);
+ ASSERT_EQ(buf[2], 47);
+
+ /* inject another event */
+ memset(buf, 0, sizeof(buf));
+ buf[0] = 1;
+ buf[1] = 47;
+ uhid_send_event(_metadata, self->uhid_fd, buf, 6);
+
+ /* read the data from hidraw */
+ memset(buf, 0, sizeof(buf));
+ err = read(self->hidraw_fd, buf, sizeof(buf));
+ ASSERT_EQ(err, 6) TH_LOG("read_hidraw");
+ ASSERT_EQ(buf[2], 52);
+}
+
/*
* Ensures that we can attach/detach programs
*/
diff --git a/tools/testing/selftests/hid/progs/hid.c b/tools/testing/selftests/hid/progs/hid.c
index 614f1aa32649..2e7e5a736dc6 100644
--- a/tools/testing/selftests/hid/progs/hid.c
+++ b/tools/testing/selftests/hid/progs/hid.c
@@ -35,6 +35,30 @@ struct hid_bpf_ops first_event = {
.hid_id = 2,
};

+int __hid_subprog_first_event(struct hid_bpf_ctx *hid_ctx, enum hid_report_type type)
+{
+ __u8 *rw_data = hid_bpf_get_data(hid_ctx, 0 /* offset */, 3 /* size */);
+
+ if (!rw_data)
+ return 0; /* EPERM check */
+
+ rw_data[2] = rw_data[1] + 5;
+
+ return hid_ctx->size;
+}
+
+SEC("?struct_ops/hid_device_event")
+int BPF_PROG(hid_subprog_first_event, struct hid_bpf_ctx *hid_ctx, enum hid_report_type type)
+{
+ return __hid_subprog_first_event(hid_ctx, type);
+}
+
+SEC(".struct_ops.link")
+struct hid_bpf_ops subprog_first_event = {
+ .hid_device_event = (void *)hid_subprog_first_event,
+ .hid_id = 2,
+};
+
SEC("?struct_ops/hid_device_event")
int BPF_PROG(hid_second_event, struct hid_bpf_ctx *hid_ctx, enum hid_report_type type)
{

--
2.44.0